JP7683553B2 - Battery monitoring device, battery transportation equipment, battery monitoring method - Google Patents

Description

This disclosure relates to a battery monitoring device, a battery transport device, and a battery monitoring method.

In rechargeable batteries such as lithium-ion batteries, abnormal heat generation can occur when a specific component inside the battery heats up due to some trigger, which in turn causes other components to heat up, causing the temperature of the battery to continue to rise unintentionally. If such an abnormal heat generation phenomenon occurs, it is undesirable because it significantly reduces the thermal reliability of the battery. Therefore, in lithium-ion batteries and the like, it is important to detect the presence or absence of abnormal heat generation in the battery to ensure thermal reliability.

Against this background, a system has been proposed that compares the sensing values of multiple sensors that detect the temperature, gas, and pressure inside a battery module with predetermined thresholds and combines the results to detect thermal runaway in the battery in advance (see, for example, Patent Document 1).

Korean Patent Publication No. 10-2021-0116050

However, Patent Document 1 only describes the detection of thermal runaway in batteries and does not provide any measures to prevent the occurrence of thermal runaway, making it an insufficient measure against heat in batteries.

The purpose of this disclosure is to provide a battery monitoring device, battery transport equipment, and battery monitoring method that can implement effective heat countermeasures for abnormal heat generation in batteries.

The invention described in claim 1 is
A battery monitoring device for monitoring a chargeable/dischargeable battery,
A factor monitoring unit (37, 53) that monitors factors that lead to an abnormal heat generation phenomenon in which the temperature of the battery continues to rise unintentionally;
An abnormality detection unit (50, 150) that detects an abnormality in the battery,
The abnormality detection unit prevents the occurrence of abnormal heat generation phenomena based on the result of monitoring the factors, detects an abnormal state occurring in the battery at an early stage of the occurrence of the abnormal heat generation phenomenon, and implements measures against the abnormal heat generation phenomenon based on the detection result of the abnormal state ;
The battery is a lithium-ion battery,
The factors include the amount of lithium deposition within the battery,
The factor monitoring unit includes a short circuit (371) that temporarily shorts both ends of the lithium ion battery to discharge it, and has a deposition amount detection unit (37) that calculates an estimated amount of lithium deposition based on a change in at least one of the current and the voltage when both ends of the lithium ion battery are shorted by the short circuit.

The invention described in claim 12 is
A battery transport device for transporting a chargeable/dischargeable battery by a moving object, comprising:
A storage container (SC) in which the battery is stored;
A factor monitoring unit (37) that monitors factors that lead to an abnormal heat generation phenomenon in which the temperature of the battery continues to rise unintentionally;
An abnormality detection unit (150) that detects an abnormality in the battery,
the abnormality detection unit prevents the occurrence of abnormal heat generation phenomena based on the factor monitoring results, detects abnormal conditions occurring in the battery at an early stage of the occurrence of the abnormal heat generation phenomena, and implements measures against the abnormal heat generation phenomena based on the detection results of the abnormal conditions ;
The battery is a lithium-ion battery,
The factors include the amount of lithium deposition within the battery,
The factor monitoring unit includes a short circuit (371) that temporarily shorts both ends of the lithium ion battery to discharge it, and has a deposition amount detection unit (37) that calculates an estimated amount of lithium deposition based on a change in at least one of the current and the voltage when both ends of the lithium ion battery are shorted by the short circuit.

This makes it possible to implement effective heat countermeasures that prevent abnormal heat generation from occurring when transporting batteries, and, in the unlikely event that abnormal heat generation does occur, take measures from the early stages of occurrence.

The invention described in claim 13 is
To monitor factors that lead to an abnormal heat generation phenomenon in which the temperature of a battery continues to rise unintentionally;
detecting an abnormality in the battery;
Detecting an abnormality in the battery includes preventing the occurrence of an abnormal heat phenomenon based on the monitoring results of factors, and detecting an abnormal state occurring in the battery at an early stage of the occurrence of the abnormal heat phenomenon and implementing measures against the abnormal heat phenomenon based on the detection results of the abnormal state ;
The battery is a lithium-ion battery,
Factors include the amount of lithium deposition inside the battery,
Monitoring the factors includes calculating an estimate of the amount of lithium deposition based on a change in at least one of the current and the voltage when the lithium ion battery is discharged by temporarily shorting both ends of the battery.

These measures will allow for effective heat countermeasures to be implemented, preventing abnormal heat generation from occurring in the first place, and in the unlikely event that abnormal heat generation does occur, taking measures from the early stages of occurrence.

The reference symbols in parentheses attached to each component indicate an example of the correspondence between the component and the specific components described in the embodiments described below.

1 is a schematic diagram showing a battery pack to which a battery monitoring device according to a first embodiment is applied; FIG. 1 is an explanatory diagram for explaining a lithium ion battery. 1 is a schematic configuration diagram of a battery management unit including a battery monitoring device. FIG. 2 is an explanatory diagram for explaining a battery monitoring device. 4 is an explanatory diagram for explaining a deposition amount detection unit included in the battery monitoring device. FIG. FIG. 4 is an explanatory diagram for explaining a method for calculating the amount of lithium deposition. FIG. 11 is an explanatory diagram for explaining how to obtain a parasitic resistance value. FIG. 4 is an explanatory diagram for explaining a flow of calculation of the amount of lithium deposition. 4 is an explanatory diagram for explaining diagnosis of the deposition amount detection unit by a diagnosis unit. FIG. FIG. 11 is an explanatory diagram for explaining a method for calculating a volume ratio SOH of a battery. 4 is a timing chart showing changes in output from various sensors before and after the occurrence of an abnormal heat generation phenomenon. 4 is an explanatory diagram for explaining the flow of a control process executed by a battery monitoring device; FIG. 1 is a schematic configuration diagram of a battery management system including a battery monitoring device. 1 is a schematic diagram of a charging system including a battery monitoring device; 5 is an explanatory diagram for explaining current and voltage during charging of a battery module in a charging system serving as a comparative example of the first embodiment. FIG. 4 is an explanatory diagram for explaining the flow of a control process executed by the battery monitoring device when charging of the battery module is started; FIG. FIG. 4 is an explanatory diagram for explaining the flow of a control process executed by a charger. 4 is an explanatory diagram for explaining the flow of a control process executed by a battery monitoring device while a battery module is being charged; FIG. 4 is an explanatory diagram for explaining current and voltage during charging of a battery module in the charging system of the first embodiment. FIG. FIG. 1 is a schematic diagram of a battery evaluation system. FIG. 1 is a schematic block diagram for explaining value assessment and use proposal of a battery module by a battery evaluation system. FIG. 4 is an explanatory diagram for explaining rebuild information generated by the battery evaluation system. 3A to 3C are explanatory diagrams for explaining the manufacturing process up to the point where the battery pack is mounted on a vehicle. FIG. 11 is an explanatory diagram for explaining some functions of a battery monitoring device according to a second embodiment. FIG. 2 is an explanatory diagram for explaining the timing of lithium precipitation in a lithium ion battery. FIG. 11 is a schematic configuration diagram of a large-capacity power storage system according to a third embodiment. FIG. 2 is an explanatory diagram for explaining an internal configuration of the large-capacity power storage system. FIG. 1 is a schematic system configuration diagram of a large-capacity power storage system. FIG. 13 is an explanatory diagram for explaining temperature control of a large-capacity power storage system serving as a comparative example of the third embodiment. FIG. 13 is an explanatory diagram for explaining temperature control of the large-capacity power storage system according to the third embodiment. FIG. 13 is an explanatory diagram for explaining a modified example of temperature control. FIG. 11 is an explanatory diagram for explaining a suitable time for battery replacement. FIG. 4 is an explanatory diagram for explaining the relationship between the charge rate and the temperature and the amount of lithium deposition. FIG. 13 is a schematic configuration diagram of a battery transport device according to a fourth embodiment. FIG. 1 is a schematic system configuration diagram of a battery transportation device.

Embodiments of the present disclosure will be described below with reference to the drawings. In the following embodiments, parts that are the same as or equivalent to those described in the preceding embodiments may be given the same reference numerals, and their description may be omitted. In addition, in the embodiments where only some of the components are described, the components described in the preceding embodiments may be applied to the other parts of the components. The following embodiments may be partially combined with each other, as long as the combination does not cause any problems, even if not specifically stated.

First Embodiment
In this embodiment, first, an example in which the battery monitoring device 20 and the battery monitoring method disclosed herein are applied to a battery management unit (hereinafter also referred to as a BMU) of a vehicle equipped with a battery pack 1, which is a high-voltage battery, will be described with reference to Figures 1 to 13. Then, in this embodiment, a charging system BCS and a battery evaluation system BRS including the battery monitoring device 20 will be described.

The BMU includes a battery pack 1 shown in FIG. 1. The battery pack 1 includes a sealed container 11 that forms an outer shell, and multiple battery modules BM, a battery monitoring device 20, and a battery ECU 100 are housed inside the sealed container 11. The sealed container 11 is provided with a high-pressure protection valve HPV for venting gas inside to the outside when the internal pressure increases. In the battery pack 1, each battery module BM is adjusted to an appropriate temperature by a temperature control device (not shown).

The battery modules BM are connected to an electric device such as an electric motor for vehicle running (not shown) and are a power source that supplies power to the electric device. The battery modules BM are electrically connected in series. The battery modules BM are also a battery pack in which a plurality of battery cells C are electrically connected in series. In this embodiment, the battery pack 1 including three battery modules BM is illustrated, but the number of battery modules BM is not limited to this and can be any number. The number of battery cells C constituting the battery module BM can also be any number. Some of the battery modules BM may be electrically connected in parallel. Hereinafter, the battery cells C and the battery modules BM may be simply referred to as batteries. In this embodiment, the battery module BM is a storage battery including a lithium-ion battery.

Battery cell C is a rechargeable secondary battery. Battery cell C is a lithium ion battery. For example, as shown in FIG. 2, a lithium ion battery is configured with lithium iron phosphate LFP or nickel manganese cobalt NMC as a positive electrode material and graphite as a negative electrode material. In addition, a lithium ion battery is configured with, for example, a positive electrode collector made of aluminum and a negative electrode collector made of copper. A lithium ion battery configured in this way has excellent charge and discharge cycle characteristics, but has the characteristic that the electrode potential is very close to the lithium deposition potential, making it easy for lithium to deposit in a charged state.

As shown in FIG. 3, the battery monitoring device 20 is electrically connected to each battery module BM via a connection member 21. The connection member 21 includes a flexible substrate FPC on which a wiring pattern is printed. The battery monitoring device 20 includes the same number of sensor units 30A, 30B, 30C as the battery modules BM, and the same number of monitoring modules 50A, 50B, 50C as the battery modules BM. Since the sensor units 30A, 30B, 30C have the same basic configuration, they will not be described individually but will be described collectively as the sensor unit 30. Furthermore, since the monitoring modules 50A, 50B, 50C have the same basic configuration, they will not be described individually but will be described collectively as the monitoring module 50.

The sensor unit 30 detects the battery state of each battery module BM. As shown in FIG. 4, the sensor unit 30 includes a temperature sensor 31, a current sensor 32, a voltage sensor 33, a strain sensor 34, a gas sensor 35, a pack internal pressure sensor 36, a deposition amount detection unit 37, and a coating detection unit 38. At least some of the various sensors constituting the sensor unit 30 are mounted on the flexible substrate FPC. It is not necessary for all of the various sensors constituting the sensor unit 30 to be mounted on the flexible substrate FPC. However, it is preferable that the temperature sensor 31, the strain sensor 34, and the gas sensor 35 are located near the battery cells C, and therefore it is desirable to mount them on the flexible substrate FPC.

The temperature sensor 31 is a sensor that detects the battery temperature of the lithium ion battery. As shown in FIG. 1, multiple temperature sensors 31 are mounted on the flexible substrate FPC. The flexible substrate FPC is mounted with the same number of temperature sensors 31 as the battery cells C or a number slightly less than the battery cells C so that the battery temperatures of all the lithium ion batteries that make up the battery module BM can be grasped. The battery temperature may be estimated from the measurement results of the internal impedance of the battery cells C. In this case, the means for estimating the battery temperature functions as the temperature sensor 31.

The current sensor 32 is a sensor that detects the current flowing through the battery module BM. When each battery module BM is electrically connected in series, one current sensor 32 is sufficient for the battery pack 1.

In addition to detecting the cell voltage of each battery cell C, the voltage sensor 33 can also detect the voltage of the battery module BM as a block voltage. The voltage sensor 33 can be configured, for example, as a flying capacitor type circuit that sequentially charges a capacitor with the cell voltage of each battery cell C and detects the voltage between the terminals of the capacitor as the cell voltage.

The strain sensor 34 is a sensor that detects the strain of each battery cell C caused by gas generation or the like inside each battery cell C. Note that the strain of the battery cell C may be detected by another sensor, such as an ultrasonic sensor, instead of the strain sensor 34.

The gas sensor 35 is a sensor for detecting gas leakage from each battery cell C. The gas sensor 35 is configured to detect at least one of hydrogen, carbon monoxide, carbon dioxide, and hydrogen fluoride, which are generated when an abnormality occurs in the lithium ion battery, for example.

The pack internal pressure sensor 36 is a sensor that detects the pressure inside the sealed container 11 of the battery pack 1 as the pack internal pressure. The pack internal pressure sensor 36 is configured, for example, as an atmospheric pressure range type pressure sensor that uses atmospheric pressure as a reference.

The deposition amount detection unit 37 is a device that detects lithium deposition in a lithium ion battery. The deposition amount detection unit 37 estimates the amount of lithium deposition from the behavior of the current and voltage when both ends of the lithium ion battery are short-circuited, utilizing the correlation between the amount of lithium deposition in the lithium ion battery and the behavior of the current and voltage when the two ends of the lithium ion battery are short-circuited.

As shown in FIG. 5, the deposition amount detection unit 37 has a short circuit 371 that temporarily shorts both ends of the lithium ion battery to discharge it, and a calculator 372 that estimates the amount of lithium deposition based on the behavior of the current and voltage when the lithium ion battery is shorted by the short circuit 371. The short circuit 371 is mounted on the flexible substrate FPC. The calculator 372 is also mounted on the monitoring module 50.

Although not shown, the short circuit 371 has a short circuit switch, a coil, and a capacitor for shorting both ends of the lithium ion battery. A self-resonant circuit is formed by the internal resistance of the lithium ion battery, the coil of the short circuit 371, and the capacitor.

When both ends of the lithium ion battery are short-circuited, the calculator 372 extracts a resistance change component that is correlated with the amount of lithium precipitation contained in at least one of the signal waveforms of the current and voltage flowing through the short circuit 371, and calculates an estimate of the amount of lithium precipitation from the extracted component.

The above estimation method is extremely simple and useful in that it can detect specific battery degradation modes by adjusting the discharge frequency from the lithium-ion battery.

On the other hand, the internal resistance of a lithium-ion battery is on the order of several mΩ to several hundred mΩ, and is easily affected by disturbances such as temperature and parasitic impedance. It has been found that it is difficult to accurately determine the amount of lithium deposition using the estimation method described above. This fact was discovered after extensive research by the present inventors.

Taking this into consideration, the calculator 372 of the deposition amount detection unit 37 calculates the amount of lithium deposition by correcting the above estimated value with both the battery temperature detected by the temperature sensor 31 and the parasitic resistance value previously stored in the memory unit 51 of the monitoring module 50, as shown in FIG. 6.

The parasitic resistance value is part of the parasitic impedance generated between the lithium ion battery and the short circuit 371. The parasitic resistance value changes depending on the battery temperature. Therefore, the calculator 372 corrects the parasitic resistance value stored in the memory unit 51 depending on the battery temperature, and calculates the amount of lithium deposition using the corrected parasitic resistance value. In addition to functioning as a means for estimating the amount of lithium deposition, the calculator 372 also functions as a calibration means for correcting the estimated value of the amount of lithium deposition.

The parasitic resistance value is obtained by connecting the deposition amount detection unit 37 to a calibration device CD having a known impedance Z before connecting it to the lithium ion battery, as shown in FIG. 7. Specifically, as shown in FIG. 8, a short circuit 371 is connected to the calibration device CD, and the parasitic resistance value is obtained in this state. The parasitic resistance value is then stored in the memory unit 51 of the monitoring module 50. Next, the short circuit 371 is connected to the battery module BM, and the lithium deposition amount is calculated in this state.

The deposition amount detection unit 37 configured in this manner can ensure robustness against parasitic impedance and temperature changes. This is extremely effective in detecting the amount of lithium deposition with high accuracy.

The short circuit 371 of this embodiment includes a coil, which makes it large in size, so it is necessary to appropriately miniaturize it while taking into consideration its mountability. Miniaturization can be achieved, for example, by improving the saturation magnetic flux density of the coil. Specific means for miniaturization include, for example, using a coil made of a material with high magnetic flux density, or improving the saturation magnetic flux density by providing a gap.

The coating detection unit 38 detects the thickness of the coating that forms at the interface between the negative electrode and the electrolyte when the lithium-ion battery is being charged. This coating is also called the SEI layer. SEI is an abbreviation for Solid Electrolyte Interphase.

The thickness of the SEI layer is correlated with the behavior of the current and voltage when both ends of the lithium ion battery are shorted by the short circuit 371. The coating detection unit 38 estimates the thickness of the SEI layer from the behavior of the current and voltage when both ends of the lithium ion battery are shorted by the short circuit 371. Specifically, when both ends of the battery are shorted by the short circuit 371, the coating detection unit 38 extracts a component that is correlated with the thickness of the SEI layer contained in at least one of the signal waveforms of the current and voltage flowing through the short circuit 371, and estimates the thickness of the SEI layer from the extracted component. Note that when detecting the thickness of the SEI layer, it is desirable to correct for the battery temperature, as in the detection of the amount of lithium precipitation.

Here, the amount of lithium precipitation and the thickness of the SEI layer are physical quantities that are more highly correlated with battery capacity degradation than the battery voltage and current. In this embodiment, the precipitation amount detection unit 37 and the coating detection unit 38 constitute a "deterioration detection unit" that detects physical quantities that are more highly correlated with battery capacity degradation than the battery voltage and current. In addition, the amount of lithium precipitation is one of the factors that lead to an abnormal heat generation phenomenon in which the battery temperature continues to rise unintentionally. For this reason, the precipitation amount detection unit 37 constitutes a "factor monitoring unit" that monitors factors that lead to an abnormal heat generation phenomenon.

As shown in FIG. 4, the flexible substrate FPC is equipped with a battery state detection unit 39 that detects the battery state. The battery state detection unit 39 detects a battery state in which the battery temperature is excessive, a battery state in which the battery is overcharged, a battery state in which the internal resistance changes significantly, etc., based on the sensor outputs of the temperature sensor 31, the current sensor 32, and the voltage sensor 33, for example.

Next, the monitoring module 50 will be described. The monitoring module 50 is a satellite module that is directly attached to the battery module BM. The monitoring module 50 is a device on the high-voltage side of the BMU. The monitoring module 50 is electrically connected to the battery and constitutes an "anomaly detection unit" that detects abnormalities in the battery.

The monitoring module 50 includes a memory unit 51, a wireless communication unit 52, an internal resistance detection unit 53, a monitoring IC 54, etc. The memory unit 51 stores various information such as a unique ID set for each monitoring module 50, the monitoring results of the battery module BM, the parasitic resistance value mentioned above, etc. The memory unit 51 is configured as a non-transient tangible storage medium.

The wireless communication unit 52 is a communication device that enables two-way communication with the battery ECU 100. The monitoring module 50 receives various signals from the battery ECU 100 and transmits the monitoring results of the monitoring module 50 to the battery ECU 100.

The internal resistance detection unit 53 is a device that detects the internal resistance of the battery based on various information output from the sensor unit 30. Furthermore, changes in the internal resistance of the battery are one of the factors that can lead to abnormal heat generation. For this reason, the internal resistance detection unit 53 constitutes a "factor monitoring unit" that monitors factors that can lead to abnormal heat generation.

The monitoring IC 54 is electrically connected to the battery and detects abnormalities in the battery. The monitoring IC 54 prevents the occurrence of abnormal heat generation based on the results of monitoring factors that lead to the abnormal heat generation phenomenon, detects abnormal conditions that occur in the battery at an early stage of the occurrence of the abnormal heat generation phenomenon, and implements measures against the abnormal heat generation phenomenon based on the results of the detection of the abnormal condition.

The monitoring IC 54 includes an ASIC circuit having an algorithm that performs at least part of the monitoring of factors that lead to abnormal heat generation and the detection of abnormal conditions that occur in the battery at the early stage of the occurrence of the abnormal heat generation phenomenon. Specifically, the monitoring IC 54 is configured to have a diagnosis unit 541, a SOH estimation unit 542, and a monitoring control unit 543 as functional units that perform various controls.

The amount of lithium deposition is a parameter that greatly affects the residual value of the battery, so it is important to verify the accuracy of this parameter. The diagnosis unit 541 compares a predetermined battery state estimated from the amount of lithium deposition with a battery state estimated from factors other than the amount of lithium deposition, and diagnoses the suitability of the deposition amount detection unit 37.

For example, as shown in FIG. 9, the diagnosis unit 541 estimates the battery volumetric rate SOH from the amount of lithium deposition detected by the deposition amount detection unit 37. The diagnosis unit 541 also estimates the battery volumetric rate SOH based on the sensor outputs of the temperature sensor 31, the current sensor 32, and the voltage sensor 33. Note that SOH is an abbreviation for State of Health.

Next, the diagnosis unit 541 compares the volumetric rate SOH estimated from the amount of lithium precipitation with the volumetric rate SOH estimated from the temperature, current, and voltage of the battery using a state comparator to diagnose the appropriateness of the precipitation amount detection unit 37. For example, if the deviation between the volumetric rate SOH estimated from the amount of lithium precipitation and the volumetric rate SOH estimated from the temperature, current, and voltage of the battery is within a predetermined range, the diagnosis unit 541 diagnoses that the precipitation amount detection unit 37 is appropriate. On the other hand, if the deviation between the volumetric rate SOH estimated from the amount of lithium precipitation and the volumetric rate SOH estimated from the temperature, current, and voltage of the battery exceeds a predetermined range, the diagnosis unit 541 diagnoses that the precipitation amount detection unit 37 is inappropriate. If the precipitation amount detection unit 37 is diagnosed as inappropriate, the monitoring IC 54 prohibits detection of the amount of lithium precipitation and control processing using the amount of lithium precipitation, or transmits a signal indicating a failure of the precipitation amount detection unit 37 to the battery ECU 100 via the wireless communication unit 52. In this embodiment, the battery volume ratio SOH is exemplified as the battery state estimated by the diagnosis unit 541, but the diagnosis unit 541 may be configured to estimate a battery state other than the volume ratio.

Here, JP2014-102076A discloses a method for calculating the full charge amount of a battery. In this calculation method, first, the current value of the output current of the battery is integrated over time to calculate the change in the charge/discharge amount between the first and second points in time. Then, the OCV at the first and second points in time is measured, and the remaining capacity SOC at the first and second points in time is calculated using the SOC-OCV curve, to calculate the change ΔSOC calculated as the deviation of the remaining capacity SOC at each point in time. Next, the full charge amount of the battery is calculated by dividing the change in the charge/discharge amount by the change ΔSOC in the remaining capacity SOC. In addition, the volume ratio SOH of the battery is obtained by dividing the full charge amount of the battery by the initial value of the full charge amount.

However, the above-mentioned method of calculating the remaining capacity SOC and the volumetric capacity SOH cannot calculate the charge/discharge amount of the battery unless a certain amount of charge or discharge occurs in order to avoid the influence of errors in the current sensor 32 and the voltage sensor 33, and therefore lacks real-time performance and has practical issues. In addition, when calculating the charge/discharge amount, there is also the issue that the calculation error of the volumetric capacity SOH increases over time due to the offset error of the current sensor 32.

Taking these factors into consideration, the SOH estimation unit 542 estimates the volumetric capacity SOH of the battery based on a physical quantity that is more highly correlated with the deterioration of the battery capacity than the battery voltage and current. The SOH estimation unit 542 constitutes a "volumetric capacity estimation unit."

One of the causes of battery deterioration is an increase in the battery's internal resistance. The battery's internal resistance is strongly correlated with physical quantities such as the amount of lithium deposition and the battery's internal resistance. In addition, the battery's internal resistance is temperature dependent and affects the battery's current and voltage.

Taking these factors into consideration, the SOH estimation unit 542 of this embodiment estimates the volumetric rate SOH using an estimation model of the volumetric rate SOH from the amount of lithium precipitation, the thickness of the SEI layer, the battery temperature, current, and voltage, as shown in FIG. 10. The estimation model of the volumetric rate SOH is, for example, a control map or function that specifies the relationship between the volumetric rate SOH, the amount of lithium precipitation, the thickness of the SEI layer, the battery temperature, current, and voltage. Note that the estimation model may be, for example, a model obtained by deep learning, reinforcement learning, or deep reinforcement learning using a neural network.

This makes it possible to diagnose the battery condition in real time, which was previously difficult when estimating the volumetric capacity SOH based on the charge/discharge amount. In addition, by accurately measuring the temperature, the effect of temperature on the battery's internal resistance can be eliminated and degradation information can be appropriately extracted, improving accuracy.

The monitoring control unit 543 prevents the occurrence of abnormal heat generation based on the results of monitoring factors that lead to the abnormal heat generation phenomenon, detects abnormal conditions that occur in the battery at the early stage of the occurrence of the abnormal heat generation phenomenon, and implements measures against the abnormal heat generation phenomenon based on the detection results of the abnormal condition. Although not shown, the monitoring IC 54 controls a circuit that equalizes the voltage of multiple battery cells C.

Next, the battery ECU 100 will be described. The battery ECU 100 is the main module in the BMU and controls the charging and discharging of each battery module BM. The battery ECU 100 is a device on the low-voltage side of the BMU.

Specifically, the battery ECU 100 is configured as a microcomputer equipped with a processor, memory, I/O, wireless communication device 110, etc. The battery ECU 100 is configured to be able to communicate with each of the monitoring modules 50A, 50B, 50C via the wireless communication device 110. The battery ECU 100 is also connected to various ECUs via a communication path such as a CAN. Examples of the various ECUs include an ECU for thermal management that controls the temperature regulator of the battery, and an ECU for an HMI device mounted on the vehicle. The battery ECU 100 is capable of reporting various battery conditions to the outside via the HMI device, etc.

The battery pack 1 configured in this manner includes a rechargeable battery such as a lithium ion battery. This type of battery can experience an abnormal heating phenomenon in which a specific component inside the battery heats up due to some trigger, which in turn causes other components to heat up, causing the battery temperature to continue to rise unintentionally. If such an abnormal heating phenomenon occurs, it is undesirable because it significantly reduces the thermal reliability of the battery. Therefore, with lithium ion batteries and the like, it is important to detect the presence or absence of an abnormal heating phenomenon in the battery to ensure thermal reliability.

Here, the changes in output from various sensors before and after an abnormal heat generation phenomenon will be described with reference to FIG. 11. FIG. 11 shows an example of the results of the inventors' verification of the changes in output from various sensors before and after an abnormal heat generation phenomenon.

As shown in FIG. 11, before the abnormal heat generation phenomenon occurs, the first symptom of an abnormality in the battery is a change in the volume of the battery caused by an increase in gas pressure inside the battery cell. This causes the output of the strain sensor 34 to show an increasing trend.

After that, when the change in the volume of the battery becomes large, the battery is damaged and gas inside the battery cell begins to leak. This causes the output of the gas sensor 35 to tend to increase. Furthermore, when the battery is damaged, the gas pressure inside the battery decreases, and the output of the strain sensor 34 tends to decrease.

Although not shown in Figure 11, as the battery deteriorates, lithium deposition occurs inside the battery and the thickness of the SEI layer increases, causing the internal resistance of the battery to increase.

When an abnormal heat generation phenomenon occurs, the battery temperature and the pressure inside the battery pack 1 (i.e., the pack internal pressure) rise sharply, and the battery voltage drops sharply. In addition, the output of the gas sensor 35 shows a tendency to increase. These symptoms become noticeable in the early stages of the occurrence of the abnormal heat generation phenomenon.

Taking these factors into consideration, the battery monitoring device 20 executes control processing to prevent and detect abnormal heat generation at an early stage. An example of the control processing executed by the battery monitoring device 20 is described below with reference to FIG. 12.

The control process shown in FIG. 12 is executed by the battery monitoring device 20 periodically or irregularly, for example, while the vehicle is running and during a period until a predetermined time has elapsed since the vehicle is stopped. Note that each process shown in this flowchart is realized by each functional unit of the battery monitoring device 20. Also, each step that realizes this process can be understood as each step that realizes the battery monitoring method.

As shown in FIG. 12, the battery monitoring device 20 reads various signals from the sensor unit 30 etc. in step S100. Then, in step S105, the battery monitoring device 20 determines whether or not an abnormal heat generation phenomenon has occurred. As described above, in the early stages of the occurrence of an abnormal heat generation phenomenon, the battery temperature, the pack internal pressure, and the output of the gas sensor 35 rise sharply, and the battery voltage drops sharply. Taking this into consideration, the battery monitoring device 20 determines whether or not an abnormal heat generation phenomenon has occurred based on at least some of the sensor outputs of the temperature sensor 31, the voltage sensor 33, the gas sensor 35, and the pack internal pressure sensor 36.

When the occurrence of an abnormal heat generation phenomenon is detected, the battery monitoring device 20 proceeds to step S110 and implements measures against the abnormal heat generation phenomenon. These measures include an external notification process that notifies the outside of the occurrence of the abnormal heat generation phenomenon, and a battery protection process that involves at least one of cooling the battery and controlling charging and discharging the battery.

In the external notification process, for example, a signal indicating the occurrence of an abnormal heat generation phenomenon is output to the battery ECU 100, and a device with a notification function, such as an HMI device, is operated via the battery ECU 100 to notify the user and battery manager of the occurrence of the abnormal heat generation phenomenon.

In the battery protection process, for example, a signal to instruct the battery ECU 100 to cool the battery is output, and the battery temperature control device is operated via the battery ECU 100 to cool the battery. Such battery cooling makes it possible to slow the progression of abnormal heat generation in the battery. In addition, in the battery protection process, for example, a signal to instruct the battery ECU 100 to limit the charging and discharging of the battery is output, and the operation of the battery is restricted to suppress self-heating of the battery. Such charge and discharge control also makes it possible to slow the progression of abnormal heat generation in the battery. The battery protection process constitutes an extension process that extends the life of the battery.

As one of the measures against the abnormal heat generation phenomenon, the battery monitoring device 20 identifies abnormal cells among the multiple battery cells C as abnormal cells based on at least one of the monitoring results of each of the multiple battery cells C and the detection results of the abnormal state of the battery. This makes it possible to restrict the use of the abnormal cells and slow the progression of the abnormal heat generation phenomenon.

Note that measures against abnormal heat generation are not limited to the above processes, and may be implemented by processes other than those described above. Measures against abnormal heat generation may include, for example, turning on a warning light or sounding an alarm.

On the other hand, if the occurrence of an abnormal heat generation phenomenon is not detected, the battery monitoring device 20 proceeds to the processing of step S115 and subsequent steps. Note that the processing of step S115 and subsequent steps is processing for preventing the occurrence of an abnormal heat generation phenomenon in advance.

In step S115, the battery monitoring device 20 determines whether or not overcharging of the battery has been detected. Battery overcharging can be detected, for example, by monitoring the sensor output of the voltage sensor 33. If battery overcharging is detected, the battery monitoring device 20 executes a charge suppression process in step S120 and returns to step S115. In this charge suppression process, the charging of the battery is suppressed and/or the battery is discharged.

If battery overcharging is not detected, the battery monitoring device 20 determines in step S125 whether or not battery overheating has been detected. Battery overheating can be detected, for example, by monitoring the sensor output of the temperature sensor 31. If battery overheating is detected, the battery monitoring device 20 implements output restriction and cooling control in step S130 and returns to step S115. Output restriction, for example, suppresses charging and discharging of the battery. Cooling control, for example, cools the battery using a battery temperature adjustment device.

If no excessive temperature rise of the battery is detected, the battery monitoring device 20 determines in step S135 whether new lithium deposition has been detected. Lithium deposition can be detected, for example, by monitoring the increase in the amount of lithium deposition detected by the deposition amount detection unit 37.

If new lithium deposition is detected, the battery monitoring device 20 performs charging, regeneration control, and heating control in step S140, and returns to step S115. In charging and regeneration control, for example, the charging of the battery is suppressed. In heating control, for example, the battery is heated by a battery temperature control device. Note that each process performed when lithium deposition is detected constitutes an extension process that extends the life of the battery.

If no new lithium deposition is detected, the battery monitoring device 20 determines in step S145 whether a change in the internal resistance of the battery has been detected. The internal resistance of the battery can be detected, for example, by monitoring the increase in the internal resistance detected by the internal resistance detection unit 53.

If a change in the battery's internal resistance is detected, the battery monitoring device 20 performs battery output limiting, temperature control, and notification of the degree of deterioration in step S150, and then returns to step S115. In output control, for example, the discharge of the battery is suppressed. In temperature control, for example, the temperature control device adjusts the battery temperature so that the battery temperature is maintained within an appropriate range. In notification of the degree of deterioration, the degree of deterioration of the battery is determined from the battery's internal resistance, and the result of the determination of the degree of deterioration or the time to replace the battery estimated from the determination result is notified to the outside. Note that each process performed when a change in internal resistance is detected constitutes an extension process that extends the life of the battery.

If no change in the internal resistance of the battery is detected, the battery monitoring device 20 determines in step S155 whether or not deformation of the battery has been detected. Deformation of the battery can be detected by monitoring the sensor output amount of the strain sensor 34.

If battery deformation is detected, the battery monitoring device 20 implements battery output restrictions in step S160 and returns to step S115. The output control includes, for example, suppressing the charging and discharging of the battery.

If no deformation of the battery is detected, there are no signs of an abnormal heat generation phenomenon, and the battery is considered to be in a normal state. Therefore, if no deformation of the battery is detected, the battery monitoring device 20 ends the control process shown in FIG. 12.

However, with the rapid electrification of vehicles, it is expected that a large amount of used batteries will be generated in the near future. Since the production of batteries involves the emission of a large amount of CO ₂ and the use of rare metals, it is expected that a battery ecosystem adapted to a circular society will be constructed by selecting reuse, rebuild, or recycling for used batteries according to the remaining capacity SOC and volumetric rate SOH of the battery. In order to construct such a battery ecosystem, it is important to correctly diagnose the value of the battery, such as the remaining capacity SOC and volumetric rate SOH. In addition, it is assumed that after the end of in-vehicle use, the battery is stored until the secondary use destination is decided, but the battery continues to discharge even when not in use, and it is also assumed that deterioration progresses depending on the storage state. Therefore, as a secondary user, it is necessary to grasp the remaining capacity SOC and volumetric rate SOH of the battery at that moment, and the real-time nature of the battery diagnosis is important.

As described above, the battery monitoring device 20 of this embodiment can determine the remaining capacity SOC and volumetric capacity SOH in real time. Considering this, it is desirable to treat the battery module BM and the battery monitoring device 20 as a battery unit UT and distribute the battery module BM in units of the battery unit UT. It is also desirable to manage the battery module BM by, for example, a battery management system BMS as shown in FIG. 13.

The battery management system BMS includes a battery monitoring device 20 and a battery management device 60 attached to the battery module BM. The battery management device 60 includes a performance determination unit 61, a value setting unit 62, and a performance notification unit 63.

The performance determination unit 61 determines whether or not the battery can be reused secondary based on the volumetric capacity SOH estimated by the SOH estimation unit 542 of the battery monitoring device 20. For example, the performance determination unit 61 determines that the battery can be reused secondary if the volumetric capacity SOH estimated by the SOH estimation unit 542 is equal to or greater than a predetermined value, and determines that the battery cannot be reused secondary if the volumetric capacity SOH is less than the predetermined value. Note that the performance determination unit 61 may be configured to determine whether or not the battery can be reused secondary based on a battery state other than the volumetric capacity SOH.

The value setting unit 62 determines whether or not there is an abnormality in the battery based on the volumetric capacity SOH estimated by the SOH estimation unit 542 of the battery monitoring device 20, and sets the remaining value of the battery if there is an abnormality in the battery. For example, the value setting unit 62 estimates the remaining value of the battery low as the volumetric capacity SOH decreases. Note that the value setting unit 62 may be configured to set the remaining value of the battery based on a battery condition other than the volumetric capacity SOH.

The performance notification unit 63 determines whether the volumetric capacity SOH estimated by the SOH estimation unit 542 of the battery monitoring device 20 is within the allowable range of the volumetric capacity SOH indicated in the battery specification data, and outputs the result of this determination to the outside.

The performance notification unit 63 acquires battery specification data provided by the battery manufacturer or the like and stores it in memory. Then, for example, if the volumetric capacity SOH estimated by the SOH estimation unit 542 is within the allowable range indicated in the specification data, the performance notification unit 63 notifies the battery distributor, secondary user, etc. of that fact. Also, for example, if the volumetric capacity SOH estimated by the SOH estimation unit 542 is outside the allowable range indicated in the specification data, the performance notification unit 63 notifies the battery distributor, secondary user, etc. of the fact that secondary reuse of the battery is difficult.

The battery monitoring device 20 and the battery monitoring method described above can provide effective measures against abnormal heat generation, effective detection of the amount of lithium precipitation, and effective estimation of the volumetric rate SOH. Specifically, this is as follows:

[Countermeasures against abnormal heat]
The battery monitoring device 20 and the battery monitoring method monitor factors that lead to abnormal heat generation phenomena, and prevent the occurrence of abnormal heat generation phenomena based on the monitoring results of the factors. In addition, the battery monitoring device 20 and the battery monitoring method detect an abnormal state occurring in the battery at an early stage of the occurrence of the abnormal heat generation phenomenon, and implement measures against the abnormal heat generation phenomenon based on the detection result of the abnormal state. This makes it possible to implement effective heat countermeasures, such as preventing the occurrence of abnormal heat generation phenomena, and implementing measures from the early stage of the occurrence, in the unlikely event that an abnormal heat generation phenomenon does occur.

In addition, the battery monitoring device 20 provides the following advantages:

(1) The monitoring module 50 of the battery monitoring device 20 performs monitoring of factors that lead to abnormal heat generation and detection of abnormal battery conditions in parallel. In other words, the monitoring module 50 performs detection of abnormal battery conditions regardless of the monitoring results of factors that lead to abnormal heat generation. This allows for earlier detection of abnormal conditions compared to, for example, a case in which abnormal conditions are detected after monitoring factors that lead to abnormal heat generation, and therefore allows for earlier implementation of measures against abnormal heat generation.

(2) Countermeasures for when an abnormal heat generation phenomenon occurs include an external notification process that notifies the outside of the occurrence of the abnormal heat generation phenomenon, or a battery protection process that involves at least one of temperature adjustment control and charging/discharging control of the battery. When the countermeasures for abnormal heat generation phenomenon include an external notification process, in addition to measures that the battery monitoring device 20 itself can take, it becomes easier to implement measures by devices external to the battery monitoring device 20 or measures in cooperation with external devices. Furthermore, when the countermeasures for abnormal heat generation phenomenon include a battery protection process, it becomes possible to appropriately protect the battery.

(3) The monitoring module 50 performs an extension process to extend the battery life in accordance with the monitoring results of factors that lead to the abnormal heat generation phenomenon. In this way, by configuring the monitoring module 50 to perform a battery life extension process in accordance with the monitoring results of factors that lead to the abnormal heat generation phenomenon, it becomes possible to appropriately extend the battery life.

(4) Factors that lead to abnormal heat generation include at least one of lithium precipitation inside the battery and the internal resistance of the battery. Lithium precipitation inside a lithium-ion battery or an increase in internal resistance can lead to abnormal heat generation in the battery. Therefore, by monitoring lithium precipitation and internal resistance, it becomes easier to prevent abnormal heat generation in the battery.

(5) The monitoring module 50 identifies abnormal cells among the multiple battery cells C as abnormal cells based on at least one of the monitoring results for each of the multiple battery cells C and the detection results for the abnormal state of the multiple battery cells C. In this way, if the configuration is capable of identifying abnormal cells from among the multiple battery cells C, it becomes possible, for example, to restrict the use of the abnormal cells, thereby preventing the occurrence of abnormal heat generation phenomena or delaying the progression of the abnormal heat generation phenomena.

(6) The monitoring module 50 is configured to be able to detect at least one of the following abnormal battery conditions: abnormal internal pressure of the sealed container 11, abnormal battery temperature, abnormal battery voltage, and abnormal gas inside the sealed container 11. In the early stages of an abnormal heat generation phenomenon, the internal pressure of the sealed container 11 that houses the battery, the temperature of the battery, the voltage of the battery, and the gas state inside the sealed container 11 become abnormal. For this reason, if the monitoring module 50 is configured to be able to detect at least one of the following abnormal internal pressure of the sealed container 11, abnormal battery temperature, abnormal battery voltage, and abnormal gas inside the sealed container 11, it becomes easier to detect an abnormal heat generation phenomenon in the early stages of its occurrence.

(7) The battery monitoring device 20 includes an ASIC circuit having an algorithm that performs at least some of the monitoring of factors that lead to abnormal heat generation and the detection of abnormal battery states. This makes it possible to monitor factors that lead to abnormal heat generation and detect abnormal states with a simple configuration.

(8) The monitoring module 50 is configured to determine the degree of battery deterioration based on the results of monitoring factors that lead to abnormal heat generation, and to be able to notify the outside of the result of the deterioration degree determination or the time to replace the battery estimated from the determination result. In this way, if the degree of battery deterioration is determined from the results of monitoring factors that lead to abnormal heat generation, a dedicated device for determining the degree of battery deterioration is not required. This contributes to simplifying the battery monitoring device 20.

(9) The connection member 21 that connects the battery and the monitoring module 50 includes a flexible substrate FPC on which a portion of the sensor unit 30 is mounted. In this way, by mounting a portion of the sensor unit 30 on the flexible substrate FPC that constitutes the connection member 21, factors that lead to abnormal heat generation in the battery can be monitored in a position close to the battery.

[Detection of Lithium Deposition Amount]
The deposition amount detection unit 37 of the battery monitoring device 20 calculates an estimate of the amount of lithium deposition based on a change in at least one of the current and voltage when both ends of the lithium ion battery are shorted by the short circuit 371. The deposition amount detection unit 37 then corrects the estimate of the amount of lithium deposition with the battery temperature. This reduces the effect of the battery temperature included in the estimate of the amount of lithium deposition, improving the detection accuracy of the amount of lithium deposition, and ensuring the reliability of the deposition amount detection unit 37.

The deposition amount detection unit 37 also corrects the estimated value of the lithium deposition amount with the parasitic resistance value stored in the memory unit 51. This reduces the effect of the parasitic impedance included in the estimated value of the lithium deposition amount, improving the detection accuracy of the lithium deposition amount, thereby ensuring the reliability of the deposition amount detection unit 37.

(1) Specifically, the deposition amount detection unit 37 corrects the parasitic resistance value stored in the memory unit 51 in accordance with the battery temperature, and calculates the amount of lithium deposition using the corrected parasitic resistance value. This reduces the influence of the battery temperature and parasitic impedance included in the estimated value of the amount of lithium deposition, thereby improving the detection accuracy of the amount of lithium deposition.

(2) The parasitic resistance value is obtained by connecting the short circuit 371 to a calibration device CD having a known impedance Z before connecting it to the lithium ion battery. This allows the parasitic resistance value of the deposition amount detection unit 37 to be obtained with high accuracy. This greatly contributes to improving the detection accuracy of the amount of lithium deposition.

(3) The battery monitoring device 20 includes a diagnostic unit 541 that compares a predetermined battery state estimated from the amount of lithium precipitation with a predetermined battery state estimated from factors other than the amount of lithium precipitation to diagnose the suitability of the precipitation amount detection unit 37. This allows the diagnostic unit 541 to diagnose the reliability of the precipitation amount detection unit 37, thereby ensuring the reliability of the precipitation amount detection unit 37.

[Modification of the battery monitoring device 20]
The battery monitoring device 20 may not be the same as that described above, and may be partially different from that described above. In addition, the technical matters described above can be applied to devices and systems other than in-vehicle devices.

[Estimation of Floor Area Ratio SOH]
The battery monitoring device 20 detects a physical quantity that is more highly correlated with battery capacity degradation than the battery voltage and current, and estimates the battery volumetric rate SOH based on the physical quantity. In this way, if the battery monitoring device 20 is configured to estimate the volumetric rate SOH using a physical quantity that is more highly correlated with battery capacity degradation, there is less need to avoid the influence of errors compared to when the volumetric rate SOH is calculated from the battery current and voltage, so the volumetric rate SOH can be estimated in a short time. Therefore, the battery monitoring device 20 of the present invention makes it possible to grasp the battery state in a practical manner.

(1) Here, the amount of lithium precipitation and the thickness of the SEI layer are physical quantities that directly affect the capacity degradation of the battery. Therefore, by detecting the amount of lithium precipitation and the thickness of the SEI layer and calculating the volumetric rate SOH based on the amount of lithium precipitation and the thickness of the SEI layer, real-time performance can be ensured. In addition, the degree of cracking of the positive electrode active material inside the battery is a physical quantity that directly affects the capacity degradation of the battery. Therefore, the accuracy of detecting the volumetric rate SOH can be improved even if the volumetric rate SOH is calculated based not only on the amount of lithium precipitation and the thickness of the SEI layer but also on the degree of cracking of the positive electrode active material. The degree of cracking of the positive electrode active material can be estimated based on the behavior of the current and voltage when both ends of the lithium ion battery are short-circuited, or on the sensor output of a strain sensor or ultrasonic sensor.

(2) The amount of lithium precipitation and the thickness of the SEI layer in a lithium ion battery are correlated with the behavior of the current and voltage when both ends of the lithium ion battery are short-circuited. Taking this into consideration, the battery monitoring device 20 calculates at least one of the amount of lithium precipitation and the thickness of the SEI layer based on the change in at least one of the current and voltage when both ends of the lithium ion battery are short-circuited by the short circuit 371.

(3) Specifically, the battery monitoring device 20 corrects at least one of the amount of lithium precipitation and the thickness of the SEI layer with the battery temperature. This reduces the influence of the battery temperature on the estimated amount of lithium precipitation and the thickness of the SEI layer, thereby improving the detection accuracy of the amount of lithium precipitation and the thickness of the SEI layer.

(4) The battery management system BMS determines whether or not a battery can be reused based on the volumetric capacity SOH estimated by the SOH estimation unit 542 of the battery monitoring device 20. This makes it easier to determine whether to reuse, rebuild, or recycle a battery when reusing it. This contributes greatly to the creation of a battery ecosystem that is adapted to a recycling-oriented society.

(5) The battery management system BMS determines whether there is a battery abnormality based on the volumetric capacity SOH estimated by the SOH estimation unit 542 of the battery monitoring device 20, and sets the residual value of the battery if there is a battery abnormality. This also makes it easier to determine whether to reuse, rebuild, or recycle when reusing batteries, thereby contributing to the creation of a battery ecosystem adapted to a circular society.

(6) The battery management system BMS determines whether the volumetric capacity SOH estimated by the SOH estimation unit 542 of the battery monitoring device 20 is within the allowable range of the volumetric capacity SOH indicated in the battery specification data, and outputs the result of this determination to the outside. This also makes it easier to determine whether to reuse, rebuild, or recycle when putting a battery to secondary use, and thus contributes greatly to the construction of a battery ecosystem adapted to a recycling-oriented society.

[Modification of Battery Management System BMS]
The battery management system BMS may not be the same as the one described above, and may be partially different from the one described above. In addition, the technical matters described above may be applied to devices and systems other than in-vehicle devices.

The above is an explanation of the BMU, etc. Below, we will explain the charging system BCS and the battery evaluation system BRS.

[BCS charging system]
The charging system BCS will be described below with reference to Figures 14 to 19. The charging system BCS is a system that charges the battery module BM included in the battery pack 1. The charging system BCS is applied to, for example, a charging station for vehicles.

As shown in FIG. 14, the charging system BCS includes a battery monitoring device 20, a battery ECU 100, a charger 120, and a charging cable CC. In this embodiment, the battery monitoring device 20 and the battery ECU 100 included in the battery pack 1 constitute a battery-side device that monitors the battery state, including the amount of lithium precipitation in the lithium-ion battery.

The battery module BM is connected to the vehicle's power control unit PCU and motor generator MG via a switch SW2 such as a system main relay. For example, when the vehicle's start switch is turned on, the switch SW2 is turned on and the battery module BM is electrically connected to the motor generator MG via the power control unit PCU, making it available for charging and discharging.

The battery monitoring device 20 and the battery ECU 100 are basically configured in the same manner as described above. The battery ECU 100 is capable of communicating with the charger 120 via the communication device CE. When the battery ECU 100 is capable of communicating with the charger 120, it notifies the charger 120 of battery information including the battery state such as the amount of lithium deposition and the remaining capacity SOC. The battery ECU 100 also determines whether the battery is in a chargeable state and notifies the charger 120 of the determination result as one piece of battery information. Furthermore, the battery ECU 100 sets the CC charging current, which is the target current amount during charging with a constant current, and the CV charging voltage, which is the target voltage during charging with a constant voltage, and notifies the charger 120 of these set values. The communication between the communication device CE and the charger 120 is performed via the CAN and the communication lines included in the charging cable CC.

The charging cable CC electrically connects the battery module BM and the charger 120. The charging cable CC includes a cable, a charging connector (not shown), a control box (not shown), etc.

The charger 120 is a device that charges the battery module BM. The charger 120 is composed of equipment that complies with charging standards such as CHAdeMO, CCS, and GB/T. A switch SW1 that turns on and off the electrical connection between the charger 120 and the battery module BM is provided between the charger 120 and the battery module BM. This switch SW1 may be provided on the charger 120 side or on the vehicle side.

The charger 120 includes an information acquisition unit 121, a charging determination unit 122, a charging control unit 123, and a charging time calculation unit 124. The information acquisition unit 121, the charging determination unit 122, the charging control unit 123, and the charging time calculation unit 124 are configured, for example, by a microcomputer equipped with a processor, memory, I/O, etc.

The information acquisition unit 121 acquires battery information including the battery state such as the amount of lithium deposition and the remaining capacity SOC from the battery monitoring device 20 and the battery ECU 100 when the battery module BM is being charged. The information acquisition unit 121 also acquires the CC charging current and the CV charging voltage from the battery ECU 100.

Here, the amount of lithium precipitation is important information indicating the safety of the battery module BM. For this reason, the information acquisition unit 121 of this embodiment is configured to notify the battery information, including the information indicating the amount of lithium precipitation, to the outside via the notification device ND. The notification device ND is composed of devices such as a display, speaker, and lamp.

The charging determination unit 122 determines whether or not the battery module BM can be charged based on the battery information acquired by the information acquisition unit 121. For example, the charging determination unit 122 determines whether or not the battery module BM can be charged based on the result of the determination made by the battery ECU 100 as to whether or not the battery module BM is in a chargeable state. The charging determination unit 122 may be configured to determine whether or not charging is possible based on the amount of lithium deposition acquired by the information acquisition unit 121, etc.

The charging control unit 123 charges the battery module BM based on the judgment result of the charging judgment unit 122. The charging control unit 123 charges the battery module BM when the judgment result of the charging judgment unit 122 indicates that the battery module BM can be charged, and does not charge the battery module BM when the judgment result indicates that the battery module BM cannot be charged.

The charging control unit 123 of this embodiment is configured to charge the battery module BM using a CCCV charging method in which charging is performed at a constant current followed by charging at a constant voltage. In the following, charging at a constant current may be referred to as CC charging, and charging at a constant voltage may be referred to as CV charging.

The charging time calculation unit 124 estimates the required charging time based on the battery state acquired by the information acquisition unit 121, and notifies the outside with information indicating the estimated required charging time by the notification device ND. The charging time calculation unit 124 can be configured to estimate the required charging time, for example, by using a control map that specifies the relationship between the remaining capacity of the battery module BM and the required charging time. When notifying the outside with the notification device ND of the required charging time, the charger 120 is preferably configured to notify the outside with information about how much the current quick charging has been shortened compared to normal charging. In addition, the charger 120 is preferably configured to notify the remaining time until charging is completed to an information terminal held by the user.

There is a demand for a charging system BCS configured as described above that is capable of faster charging with a higher energy density. Recently, attempts have been made to shorten the charging time of the battery module BM by making the charger 120 compatible with 50 kW for CHAdeMO 1.0 specifications, 400 kW for CHAdeMO 2.0 specifications, and 900 kW for CHAdeMO 3.0 specifications.

Charging times can be shortened by increasing the charging power, but the increased charging current caused by high-power charging accelerates lithium deposition on the battery's negative electrode, which can significantly reduce the battery's lifespan and safety.

To avoid this, a charging profile can be considered that prevents deterioration or unsafe conditions, such as performing a pre-charge with a small current before CC charging, as shown in Figure 15, to detect abnormalities such as deep discharge of the battery.

However, if preliminary charging is performed for safety reasons, the charging time will be longer, which may cause inconvenience to the user. Furthermore, if the charging time is longer than expected, the user may feel anxious or irritated.

Taking these factors into consideration, the charging system BCS of this embodiment is configured so that the charger 120 determines whether or not the battery module BM can be charged based on battery information acquired from the battery monitoring device 20 and the battery ECU 100.

The control process on the battery ECU 100 side when charging of the battery module BM starts will be described below with reference to FIG. 16. This control process is performed periodically or irregularly by the battery ECU 100. Each control step of the control process shown in FIG. 16 constitutes a function realization unit that realizes various functions executed by the battery ECU 100.

As shown in FIG. 16, in step S200, the battery ECU 100 determines whether the charger 120 is connected. The battery ECU 100 waits until the charger 120 is connected, and when the charger 120 is connected, the process proceeds to step S210.

In step S210, the battery ECU 100 executes an initial process. In the initial process, the battery ECU 100 initializes flags and acquires the monitoring results of the battery monitoring device 20.

Then, the battery ECU 100 judges whether the battery module BM is in a state in which charging is possible. For example, the battery ECU 100 judges that charging is possible if the amount of lithium deposition is within a predetermined value, and judges that charging is not possible if the amount of lithium deposition exceeds the predetermined value. The battery ECU 100 may also be configured to judge that charging is not possible if the battery module is in an overcharged state or a deep discharged state.

If charging to the battery module BM is possible, the battery ECU 100 sets the charge amount to the battery module BM in step S230. The battery ECU 100 determines the charge amount to the battery module BM based on, for example, the remaining capacity SOC and volumetric capacity SOH of the battery module BM. The battery ECU 100 also sets the CV charging voltage in step S240. The battery ECU 100 sets, for example, a voltage value recommended as the charging voltage of the battery module BM as the CV charging voltage. Furthermore, the battery ECU 100 sets the CC charging current in step S250. The battery ECU 100 sets, for example, a current value recommended as the charging current of the battery module BM as the CC charging current. The battery ECU 100 then notifies the charger 120 of various settings including battery information indicating the battery state including the amount of lithium precipitation, the CV charging voltage, and the CC charging current, and exits this control process.

On the other hand, if charging to the battery module BM is not possible, the battery ECU 100 notifies the charger 120 that charging to the battery module BM is not possible in step S270, and exits this control process.

Next, the control process on the charger 120 side when charging the battery module BM will be described with reference to FIG. 17. This control process is performed periodically or irregularly by the charger 120. Each control step of the control process shown in FIG. 17 constitutes a function realization unit that realizes various functions executed by the charger 120.

As shown in FIG. 17, in step S300, the charger 120 determines whether or not it has received a notification issued by the battery ECU 100. The charger 120 waits until it receives a notification from the battery ECU 100, and when it receives a notification from the battery ECU 100, it proceeds to step S310. In step S310, the charger 120 determines whether or not it is possible to charge the battery module BM based on the notification from the battery ECU 100. The process of step S310 is performed by the charging determination unit 122 of the charger 120.

If the notification from the battery ECU 100 indicates that charging is not possible, the charger 120 notifies the outside, in step S320, by the notification device ND, of information indicating that charging to the battery module BM is not possible and information indicating the amount of lithium deposition, and does not charge the battery module BM.

On the other hand, if the notification from the battery ECU 100 indicates that charging is possible, the charger 120 starts CC charging in step S330. The charger 120 charges the battery module BM with the CC charging current set by the battery ECU 100 as the target current amount.

Then, in step S340, the charger 120 determines whether the voltage of the battery module BM has reached a predetermined voltage. This determination process is to determine whether it is time to switch from CC charging to CV charging. The predetermined voltage is set to, for example, the CV charging voltage.

If the voltage of the battery module BM has not reached the predetermined voltage, the charger 120 determines in step S350 whether it has received a notification from the battery ECU 100 to update the CC charging current setting.

Here, the battery ECU 100 periodically or irregularly executes the setting update process shown in FIG. 18 during CC charging. Specifically, as shown in FIG. 18, the battery ECU 100 determines whether the amount of lithium deposition is greater than a predetermined threshold in step S500. This threshold is set to a value that assumes the amount of lithium deposition that will be deposited when the battery is abnormal. If the amount of lithium deposition is equal to or less than the predetermined threshold, the battery ECU 100 skips the subsequent steps and exits from the setting update process, and if the amount of lithium deposition is greater than the predetermined threshold, the battery ECU 100 proceeds to step S510. In step S510, the battery ECU 100 resets the CC charging current to be smaller than the current value. For example, the battery ECU 100 resets the CC charging current to the current value before the amount of lithium deposition exceeds the predetermined threshold. Then, in step S520, the battery ECU 100 notifies the charger 120 of the update of the CC charging current setting.

Returning to FIG. 17, when the charger 120 receives notification from the battery ECU 100 of an update to the CC charging current setting, in step S360, the charger 120 updates the CC charging current to the current amount notified by the battery ECU 100. That is, when the amount of lithium deposition increases beyond a predetermined threshold during CC charging, the charger 120 reduces the amount of constant current. The process of step S360 is performed by the charging control unit 123 of the charger 120.

When the voltage of the battery module BM reaches a predetermined voltage, the charger 120 proceeds to step S370 and starts CV charging. The charger 120 charges the battery module BM with the CV charging voltage set by the battery ECU 100 as the target voltage.

Next, in step S330, the charger 120 determines whether the current flowing through the battery module BM is equal to or less than a predetermined value, or whether the time elapsed since the start of charging the battery module BM is equal to or greater than a predetermined time.

If the current flowing through the battery module BM is greater than a predetermined value and the elapsed time from the start of charging is within a predetermined time, the charger 120 continues CV charging. If the current flowing through the battery module BM is equal to or less than a predetermined value or the elapsed time from the start of charging exceeds a predetermined time, the charger 120 executes a charging termination process in step S390 and then exits this control process. In the charging termination process, for example, the notification device ND notifies the user of charging completion, charge amount, battery state, etc.

The charging system BCS described above includes a charger 120 for a battery module BM including a lithium-ion battery. The charger 120 includes an information acquisition unit 121 that acquires battery information from the battery-side device, a charging determination unit 122 that determines whether the battery module BM can be charged based on the battery information, and a charging control unit 123 that charges the battery module BM based on the determination result of the charging determination unit 122. In this way, if the charger 120 is configured to determine whether the battery module BM can be charged based on the battery information acquired from the battery-side device, the charging time can be shortened compared to a case in which the charger 120 determines whether the battery module BM can be charged by performing a preliminary charge.

The charging system BCS of this embodiment also has the following features:

(1) The charge control unit 123 of the charger 120 is configured to charge the battery module BM by a CCCV charging method in which charging is performed at a constant current followed by charging at a constant voltage. Then, as shown in FIG. 19, for example, when the amount of lithium deposition during CC charging increases beyond a predetermined threshold, the charge control unit 123 reduces the amount of constant current. This suppresses the amount of lithium deposition during CC charging, thereby ensuring the safety of the battery module BM while suppressing the charging time of the battery module BM from becoming longer.

(2) When charging by the charger 120 is started, the battery side device periodically determines whether the amount of lithium deposition has increased beyond a threshold. Then, when the amount of lithium deposition has increased beyond the threshold, the battery side device sets the target current amount for constant current charging to a value smaller than the current current amount and notifies the charger 120 of the target current amount. When the charging control unit 123 acquires the target current amount from the battery side device during CC charging, it adjusts the amount of constant current based on the target current amount. In this way, if the battery side device is configured to periodically monitor the amount of lithium deposition and the charger 120 adjusts the current amount suitable for constant current charging based on the monitoring result, it is possible to control the charging rate to be maximized so that lithium deposition does not occur. This makes it possible to appropriately shorten the waiting time due to the user's charging time.

(3) The charger 120 estimates the required charging time based on the battery state, and notifies the outside world of the estimated required charging time via the notification device ND. This allows the user to know the approximate waiting time, thereby reducing the psychological burden on the user when charging the battery module BM.

(4) The charger 120 notifies the outside world of information indicating the amount of lithium deposition by the notification device ND. In this way, if it is possible to provide the user with information indicating the amount of lithium deposition in addition to information indicating the required charging time, the user will be able to understand the safety of the lithium ion battery, which will help reduce the user's concerns about lithium ion batteries.

[Modification of the charging system BCS]
The charging system BCS may not be the same as the one described above, and may be partially different from the one described above. In addition, the technical matters described above may be applied to devices and systems other than in-vehicle devices.

[Battery Evaluation System BRS and Battery Evaluation Method]
Lithium ion batteries may experience lithium precipitation when charged at low temperatures or at high speeds. If lithium precipitation progresses, it may cause an internal short circuit, which may lead to fire or smoke. Therefore, when reusing storage batteries, including lithium ion batteries, it is advisable to understand the safety of the batteries by taking into account not only the degree of deterioration but also the degree of lithium precipitation.

Taking this into consideration, the battery evaluation system BRS and the battery evaluation method of this embodiment are configured to determine the safety of the storage battery based on the amount of lithium deposition. In addition, the battery evaluation system BRS functions as a support system that supports the reuse and rebuilding of the battery module BM. The battery evaluation system BRS and the battery evaluation method will be described below with reference to Figures 20 to 22.

As shown in FIG. 20, the battery evaluation system BRS includes a battery monitoring device 20 as a battery monitoring unit that monitors the battery state of the battery module BM, and an evaluation device 130 that evaluates the battery module BM.

The battery monitoring device 20 is basically configured in the same manner as described above. The battery monitoring device 20 is configured to be able to calculate the amount of lithium precipitation in the lithium ion batteries included in the battery module BM as an index indicating the battery state. The battery monitoring device 20 is capable of outputting battery state information, etc., including the monitoring results of the battery state, including the amount of lithium precipitation, to the outside, using the wireless communication unit 52 of the monitoring module 50. In addition to the amount of lithium precipitation, this battery state information includes battery form information indicating the use of the battery module BM, the usage history of the battery module BM, etc. Note that the battery monitoring device 20 may be configured to be able to output battery state information, etc., to the outside by a communication device other than the wireless communication unit 52 of the monitoring module 50.

The evaluation device 130 is configured to be able to communicate with the battery monitoring device 20, a data center storing market buying and selling information for reused batteries, and information terminals UA, UB, UC, etc. owned by users, distributors, secondary users, etc., via a wired or wireless communication network. The evaluation device 130 acquires battery status information from the battery monitoring device 20, and evaluates the battery module BM based on the battery status information. The evaluation device 130 of this embodiment includes a safety determination unit 131, a value calculation unit 132, a use proposal unit 133, a reuse determination unit 134, and an information output unit 135.

The safety determination unit 131 determines the safety of the battery module BM based on the amount of lithium precipitation in the lithium ion batteries included in the battery module BM. The safety determination unit 131 determines that the lower the amount of lithium precipitation, the higher the safety, and the higher the amount of lithium precipitation, the lower the safety. If the battery module BM contains even one unsafe lithium battery, the safety of the battery module BM is compromised. For this reason, the safety determination unit 131 is capable of ranking the safety of each of the multiple lithium ion batteries included in the battery module BM based on the amount of lithium precipitation.

The value calculation unit 132 calculates the value of the battery module BM taking into account the results of the safety assessment of the battery module BM. For example, the value calculation unit 132 calculates the value of a battery module BM with high safety as being more expensive than a battery module BM with low safety.

21, for example, the value calculation unit 132 acquires the deterioration state based on the volumetric capacity SOH, safety based on the amount of lithium precipitation, battery form information including applications, and usage history from the battery monitoring device 20, and also acquires market buying and selling information of reused batteries from the data center. The value calculation unit 132 then calculates the purchase price of the battery module BM based on the deterioration state, safety, battery form information, usage history, and market buying and selling information. The value calculation unit 132 refers to a map that associates the deterioration state, safety, battery form information, usage history, market buying and selling information, and the purchase price of the battery module BM, for example, and calculates the purchase price of the battery module BM based on the information acquired from the battery monitoring device 20 and the data center. The value calculation unit 132 may also be configured to calculate the sales price of the battery module BM.

The usage suggestion unit 133 takes into account the safety assessment result of the battery module BM and proposes transitional usage of the battery module BM when it is reused. For example, as shown in FIG. 21, the usage suggestion unit 133 proposes recommended usage of the battery module BM when it is reused based on the deterioration state, safety, battery form information, and usage history. For example, the usage suggestion unit 133 refers to a map that associates the deterioration state, safety, battery form information, usage history, and usage when it is reused, and finds the recommended usage of the battery module BM when it is reused based on the information acquired from the battery monitoring device 20.

The reuse determination unit 134 determines whether or not the lithium ion batteries can be reused, taking into account the safety of each of the multiple lithium ion batteries that make up the battery module BM. For example, the reuse determination unit 134 determines that the lithium ion batteries can be reused if the amount of lithium precipitation is equal to or less than a predetermined value, and determines that the lithium ion batteries cannot be reused if the amount of lithium precipitation exceeds the predetermined value.

When reusable lithium-ion batteries are rearranged to rebuild different batteries, the information output unit 135 outputs a combination of lithium-ion batteries suitable for the intended use of the different batteries as rebuild information, taking into account the safety of the lithium-ion batteries, as shown in FIG. 22.

Here, the optimal combination of lithium ion batteries may differ depending on how the rebuilt battery will be used. For this reason, it is desirable for the information output unit 135 to output a combination that corresponds to how the rebuilt battery will be used to the rebuild system RS that manufactures the rebuilt battery. For example, if the rebuilt battery will be used for a long period of time, such as a stationary type, the information output unit 135 outputs a combination that provides a long life and high safety as rebuild information. Also, for example, if the rebuilt battery will be used for a short period of time, the information output unit 135 outputs a combination that prioritizes factors other than life as rebuild information.

The battery evaluation system BRS and battery evaluation method described above monitor the battery state of the battery module BM and evaluate the battery module BM based on battery state information including the monitoring results of the battery state. The battery monitoring device 20 calculates the amount of lithium precipitation in the lithium ion battery as an index showing the battery state. The evaluation device 130 judges the safety of the battery module BM based on the amount of lithium precipitation. In this way, since an index related to the safety of the battery module BM, such as the lithium precipitation state, is judged, it becomes possible to appropriately perform an evaluation, including whether or not the safety requirements are met.

The battery evaluation system BRS and battery evaluation method of this embodiment also have the following features:

(1) The evaluation device 130 includes a value calculation unit 132 that calculates the value of the battery module BM by taking into account the results of the safety assessment of the battery module BM. This makes it possible to provide the user with information on the fair value of the battery module BM.

(2) The evaluation device 130 includes a usage suggestion unit 133 that takes into account the results of the safety assessment of the battery module BM and suggests usages for the battery module BM when it is reused. This makes it possible to provide the user with information on appropriate usages for the battery module BM.

(3) The evaluation device 130 ranks the safety of each of the multiple lithium ion batteries included in the battery module BM based on the amount of lithium precipitation. This makes it possible to provide the user with information on the proper state of the multiple lithium ion batteries that make up the battery module BM.

(4) The evaluation device 130 includes a reuse determination unit 134 that determines whether or not the lithium ion batteries can be reused, taking into account the safety of each of the multiple lithium ion batteries. This makes it easier to reuse the safe lithium ion batteries in the battery module BM, even if the entire battery module BM cannot be reused.

(5) When reusing reusable lithium-ion batteries to rebuild a battery other than the battery module BM, the evaluation device 130 takes into account the safety of the lithium-ion batteries and outputs a combination of lithium-ion batteries suitable for the application of the other battery as rebuild information. As a result, even if the entire battery module BM cannot be reused, it becomes easier to build and reuse another storage battery using the highly safe lithium-ion batteries in the battery module BM.

(6) In addition to the amount of lithium precipitation, the battery status information includes at least one of the use, usage history, and degradation state of the lithium ion battery. In this way, if the battery module BM is configured to be evaluated using various information, it becomes possible to evaluate the battery module BM from multiple perspectives.

[Modifications of the battery evaluation system BRS and the battery evaluation method]
The battery evaluation system BRS and the battery evaluation method may not be the same as those described above, and may be partially different from those described above. In addition, the technical matters described above can be applied to devices and systems other than in-vehicle devices.

Second Embodiment
Next, a second embodiment will be described with reference to Figures 23 to 25. In this embodiment, an example will be described in which the cause of an abnormality in a battery module BM is identified based on the usage history and manufacturing history of the battery module BM.

First, the manufacturing process up to mounting the battery pack 1 on a vehicle will be described with reference to FIG. 23. As shown in FIG. 23, the battery pack 1 is mounted on the vehicle through a manufacturing process of the battery cells C → a manufacturing process of the battery module BM → a manufacturing process of the battery pack 1 → a process of assembling the battery pack to the vehicle.

The manufacturing process for battery cells C involves forming the electrode body, assembling the cell, injecting electrolyte, initial charging and discharging, and a performance test, in that order. In this performance test, for example, inspection equipment is used to carry out visual inspection of the battery cells C alone, foreign object inspection, battery characteristic inspection, etc.

Here, in lithium-ion batteries, lithium ions can be reduced and precipitated at the negative electrode. In particular, when charging with a large current or at a low temperature, or when metallic foreign matter is mixed into the battery and the current density is concentrated, the lithium ions released from the positive electrode active material cannot enter the negative electrode active material and tend to precipitate on the surface of the negative electrode. When lithium precipitates on the negative electrode, the amount of lithium ions contributing to the battery reaction decreases, which may lead to a decrease in capacity or the occurrence of an internal short circuit.

For this reason, in the manufacturing process of battery cell C, the current and temperature conditions under which lithium precipitation does not occur are calculated and mapped, and manufacturing techniques and inspections are implemented to prevent the inclusion of metallic foreign matter in battery cell C. In the manufacturing process of battery cell C, for example, the electrode surface of battery cell C is inspected for the presence or absence of lithium precipitation by shining light on it, and the ease of lithium precipitation is inspected by measuring the resistance distribution on the surface of the negative electrode active material.

In the next manufacturing process of the battery module BM, module assembly is performed by assembling the battery cells C together, and sensor assembly is performed by assembling the sensor unit 30 and the like to the battery cell C assembly. In this manufacturing process of the battery module BM, the battery monitoring device 20 is attached to the battery module BM. As a result, at the manufacturing stage of the battery module BM, the amount of lithium deposition, etc. can be monitored by the battery monitoring device 20.

The next manufacturing process for the battery pack 1 involves pack assembly, in which the battery modules BM are assembled together and housed in a sealed container 11. In this process, inspections such as checking electrical continuity are carried out as appropriate.

In the subsequent vehicle assembly process, the battery pack 1 is assembled into the vehicle and a vehicle inspection is carried out. During the vehicle inspection, electrical continuity with the on-board equipment is checked, etc. After that, the vehicle equipped with the battery pack 1 is shipped from the factory to the user.

While it is possible to disassemble the battery cell C and inspect the amount of lithium deposition, this inspection method is difficult to implement on battery cells C that are actually in use or in the manufacturing process, let alone in the development stage.

In response to this, the battery monitoring device 20, as shown in FIG. 24, is equipped with a deposition amount detection unit 37 that calculates the amount of lithium deposition using the output of a sensor installed in the battery module BM, and a memory unit 51 that stores the change in the amount of lithium deposition over time as one of the battery usage histories.

For example, when the user drives the vehicle, the battery monitoring device 20 stores the amount of lithium deposition, etc., as part of the usage history in the storage unit 51, which is a storage medium. The battery monitoring device 20 also stores the amount of lithium deposition, etc., during the manufacturing process of the battery module BM, the manufacturing process of the battery pack 1, and the vehicle assembly process, as part of the manufacturing history, in the storage unit 51 or an external storage device.

The battery monitoring device 20 also includes an abnormality identification unit 544 that, when an abnormality occurs in the lithium ion battery, identifies the cause of the abnormality in the lithium ion battery based on the usage history stored in the memory unit 51 and the manufacturing history stored in the memory unit 51 and an external storage device. The abnormality identification unit 544 uses the manufacturing history as reference data and compares the manufacturing history with the usage history to identify the time when the abnormality in the lithium ion battery occurred, and identifies the cause of the abnormality in the lithium ion battery by verifying the battery state before and after the time of occurrence. For example, as shown in FIG. 25, the abnormality identification unit 544 identifies the timing when the amount of lithium precipitation increases as the time when the abnormality in the lithium ion battery occurred.

Otherwise, it is the same as the first embodiment. The battery monitoring device 20 of this embodiment can obtain the same effects as the first embodiment, which are achieved from a common configuration or an equivalent configuration to the first embodiment.

In addition, the battery monitoring device 20 of this embodiment has the following features:

(1) The battery monitoring device 20 includes a memory unit 51 that stores the change over time in the amount of lithium precipitation as one of the usage or manufacturing histories of the lithium ion battery. This allows the amount of lithium precipitation to be detected non-destructively and appropriately in a short time, and allows inspection of the lithium precipitation state to be carried out. In particular, since a sensor for detecting lithium precipitation is installed in the battery module BM, it is possible to detect the lithium precipitation state regardless of time or place. Furthermore, by storing the change over time in the amount of lithium precipitation in the memory unit 51 as one of the usage or manufacturing histories of the lithium ion battery, it is possible to clearly determine when lithium was precipitated. This has the advantage of making it clear who is responsible for lithium precipitation.

(2) Furthermore, the battery monitoring device 20 includes an abnormality identification unit 544 that, when an abnormality occurs in the lithium-ion battery, identifies the cause of the abnormality in the lithium-ion battery based on the usage history and the manufacturing history of the lithium-ion battery. In this way, if the cause of the abnormality in the lithium-ion battery is identified based on history information, including not only the usage history but also the manufacturing history, it is possible to trace the cause of the abnormality back to the manufacturing stage, not just the usage stage. This contributes greatly to clarifying where responsibility lies.

(Modification of the second embodiment)
The battery monitoring device 20 of the second embodiment is not the same as that described above, and may be partially different from that described above. In addition, the technical matters described in the second embodiment can be applied to devices and systems other than in-vehicle devices.

Third Embodiment
Next, a third embodiment will be described with reference to Fig. 26 to Fig. 33. In this embodiment, an example in which the battery management unit BMU of the present disclosure is applied to a stationary large-capacity power storage system BSS will be described.

As shown in Figures 26, 27, and 28, the large-capacity power storage system BSS includes a storage container SC, multiple battery modules BM, a blower device CM, a heater device HM, a battery management unit BMU, etc.

The battery modules BM are each a storage battery including a lithium ion battery. A sensor unit 30 is installed in each of the battery modules BM. This sensor unit 30 is configured in the same manner as described in the first embodiment.

The storage container SC is a container that stores multiple battery modules BM. The storage container SC is provided with appropriate openings to ensure ventilation. The storage container SC is provided with a blower device CM and a heater device HM.

The blower CM is a cooling element for the battery module BM, and generates an airflow inside the storage container SC. The blower CM may be configured as a device that draws air into the storage container SC, or may be configured as a device that pushes air into the storage container SC. The operation of the blower CM is controlled in response to a control signal from the battery control device 140, which will be described later.

The heater device HM is a heating element of the battery module BM and includes a heating element that generates heat when electricity is applied. The heater device HM may be configured to directly heat the battery module BM, or may be configured to indirectly heat the battery module BM. The operation of the blower device CM is controlled in response to a control signal from the battery control device 140 described below.

The battery management unit BMU manages multiple battery modules BM. The battery management unit BMU includes a sensor unit 30 that monitors the battery state, including the amount of lithium precipitation in the lithium ion battery, and a battery control device 140 that controls the charging of the multiple battery modules BM.

The battery control device 140 controls the charging of the multiple battery modules BM based on the battery state monitored by the sensor unit 30. The battery control device 140 charges the multiple battery modules BM using, for example, electricity obtained by solar power generation or electricity during times when electricity rates are low.

The battery control device 140 is also connected to an alarm device ND. The battery control device 140 notifies the outside of the battery state and other information monitored by the sensor unit 30 via the alarm device ND.

In lithium-ion batteries, the electrode potential during charging drops to close to the redox potential of lithium, making lithium more likely to precipitate in situations such as low-temperature charging, large-capacity charging, and overcharging. Lithium precipitation reduces the available lithium ions inside the battery, causing a rapid decrease in battery capacity. Furthermore, if lithium precipitation continues, it can cause an internal short circuit and, in the worst case, lead to thermal runaway of the battery.

Furthermore, once a battery fails, it may not be possible to store the energy it generates until it becomes widespread, which can cause significant damage to users and businesses. Therefore, in order to continue using batteries safely and securely, it is necessary to properly manage the temperature of lithium-ion batteries while charging and discharging them, as well as to detect early signs of battery failure, such as internal short circuits, and minimize downtime.

In response to this, for example, as shown in FIG. 29, when the temperature of the lithium ion battery falls below a predetermined low temperature threshold, it is possible to use the power stored in the battery as a power source to raise the temperature of the battery using a heating element such as a heater device HM.

However, the above method is a control method that focuses only on the battery temperature, and depending on the charge/discharge rate of the battery, it may not be necessary to raise the temperature of the battery. Also, if the focus is only on the battery temperature, the battery temperature may be controlled excessively, resulting in excessive use of the power stored in the battery. In addition, in the case of a large-scale energy storage facility such as a large-capacity energy storage system BSS, the battery temperature distribution becomes complex, making it difficult to properly grasp the battery temperature. Also, it is difficult to detect battery failures such as internal short circuits early with only the temperature information of lithium-ion batteries, and the system may break down before the operator has time to secure the appropriate maintenance man-hours, resulting in significant downtime. The charge/discharge rate is the speed of charging and discharging.

Taking these factors into consideration, the battery control device 140 is configured to heat the lithium ion battery in accordance with the amount of lithium deposition during charging control. Note that lithium deposition can occur at times other than charging control. For this reason, it is desirable for the battery control device 140 to heat the lithium ion battery in accordance with the amount of lithium deposition, not limited to charging control.

As shown in FIG. 30, for example, when the amount of lithium precipitation increases beyond the first precipitation threshold Hi, the battery control device 140 starts passing electricity through the heater device HM to heat the battery module BM. Heating the battery module BM reduces the amount of lithium precipitation. Then, when the amount of lithium precipitation falls below a second precipitation threshold Lo that is smaller than the first precipitation threshold Hi, the battery control device 140 stops passing electricity through the heater device HM to stop heating the battery module BM.

As mentioned above, lithium precipitation occurs not only during low-temperature charging, but also in situations such as large-capacity charging and overcharging. In situations such as large-capacity charging and overcharging, the battery temperature of the battery module BM may be somewhat high.

For this reason, the battery control device 140 may be configured to heat the lithium ion battery in accordance with the amount of lithium precipitation and the temperature of the battery module BM. For example, as shown in FIG. 31, the battery control device 140 may be configured to energize the heater device HM to heat the battery module BM when the amount of lithium precipitation increases beyond the first precipitation threshold Hi and the battery temperature of the battery module BM falls below a predetermined low temperature threshold.

When the battery temperature of the battery module BM exceeds the low temperature threshold and the amount of lithium deposition exceeds the first deposition threshold Hi, the battery control device 140 restricts the charging and discharging of the battery module BM and notifies the outside of the battery abnormality using the alarm device ND.

Here, in order to reduce downtime, it is desirable to replace the battery during the period from when the battery's volumetric capacity SOH decreases to a certain degree due to deterioration until the amount of lithium deposition reaches a level that would cause an internal short circuit in the battery, as shown in FIG. 32, for example.

Taking this into consideration, the battery control device 140 of this embodiment estimates the desirable battery replacement period from the change in volumetric capacity SOH and the change in the amount of lithium deposition output by the sensor unit 30, and notifies the outside of the battery replacement period as the recommended period by the notification device ND. This allows businesses and the like to know the recommended battery replacement period, making it possible to reduce downtime due to system failures, including maintenance and battery failures.

Otherwise, it is the same as the first embodiment. The battery management unit BMU of this embodiment can obtain the same effects as the first embodiment, which are achieved from a common configuration or an equivalent configuration to the first embodiment.

The battery management unit BMU of this embodiment also has the following features:

(1) When the amount of lithium precipitation increases beyond a predetermined threshold, the battery management unit BMU heats the battery module BM using a heater device HM that raises the temperature of the battery module BM. By heating the lithium ion battery at the timing when the amount of lithium precipitation increases, the increase in the amount of lithium precipitation is appropriately suppressed, allowing the lithium ion battery to be used in a safe and highly efficient manner. In particular, the battery management unit of this proposal is suitable for large-scale power storage facilities where the temperature distribution is likely to expand.

(2) The sensor unit 30 includes a temperature sensor 31 that detects the battery temperature of the lithium ion battery. The battery control device 140 may be configured to heat the battery module BM using the heater device HM when the amount of lithium deposition increases beyond a predetermined threshold and the battery temperature falls below a predetermined low temperature threshold. This also allows the lithium ion battery to be used in a safe and highly efficient manner.

(Modification of the third embodiment)
In the third embodiment, the battery management unit BMU of the large-capacity power storage system BSS has been described in detail, but the battery management unit BMU may not be the same as that described above, and may be partially different from that described above.

The technical matters described in the third embodiment can also be applied to devices and systems other than the large-capacity power storage system BSS. The battery management unit BMU can be applied, for example, to power supply management for moving objects such as vehicles.

In the third embodiment, the heating element is configured as a heater device HM, but this is not limited thereto, and the heating element may be configured as a load device located around the battery. In addition, the heating element may be heated by a power supply from a source other than the battery module BM.

Here, the amount of lithium deposition tends to be large when the battery temperature is low and the charge rate is high, and tends to be small when the battery temperature is high and the charge rate is low. Thus, there is a certain correlation between the amount of lithium deposition, the charge rate, and the battery temperature. For this reason, the deposition amount detection unit 37 may calculate the amount of lithium deposition by referring to a control map that specifies the correlation between the amount of lithium deposition, the charge rate, and the battery temperature, as shown in FIG. 33, for example. This also applies to other embodiments.

Fourth Embodiment
Next, a fourth embodiment will be described with reference to Fig. 34 and Fig. 35. In this embodiment, a battery transport device BSC that stores batteries in a storage container SC and transports them will be described.

Lithium-ion batteries contain toxic and flammable chemicals, so they need to be transported safely. For example, international regulations stipulate packaging standards for transport by aircraft according to the lithium content. Batteries used in electric vehicles contain a large amount of lithium, so transporting them by aircraft is legally difficult, and they are generally transported by sea on ships. Compared to air transport, sea transport takes longer. For example, in summer, long transport times are required under high temperature and humidity conditions, and in winter, long transport times are required under low temperature conditions. Under such stressful conditions, once a lithium-ion battery transitions to an unsafe state, it becomes difficult to control the lithium-ion battery, and there is a risk of harm to other cargo or passengers, so it is important to monitor the safety state of the lithium-ion battery.

In response to this, it is conceivable that lithium-ion batteries could be transported using a transport container made of non-flammable materials and equipped with a cooling mechanism, and if an unsafe event involving the battery is detected using the gas sensor 35, the cooling mechanism could be used to deactivate the lithium-ion battery.

However, the chemical reaction that leads to an unsafe state in a lithium-ion battery is a chain reaction of exothermic reactions, and when a gas sensor 35 is used to detect an unsafe event in the battery as in the above method, the chain reaction has already begun when gas is released from the lithium-ion battery. Because the chain reaction progresses rapidly, it is difficult to inactivate the lithium-ion battery at such a point. Furthermore, the released gas is harmful, and may cause damage to cargo and passengers.

Taking these factors into consideration, the battery transport device BSC of this embodiment is configured to monitor factors that lead to abnormal heat generation, in which the temperature of the battery continues to rise unintentionally, and to detect abnormal conditions that occur in the battery at the early stages of the occurrence of the abnormal heat generation phenomenon based on the monitoring results.

As shown in FIG. 34, the battery transport device BSC includes a storage container SC that stores multiple battery modules BM, a sensor unit 30A that detects the battery state of the multiple battery modules BM, and an abnormality detection unit 150.

As shown in FIG. 35, the sensor unit 30A includes a humidity sensor HS and an acceleration sensor GS in addition to the temperature sensor 31, gas sensor 35, and deposition amount detection unit 37 described in the first embodiment. The humidity sensor HS is installed inside the storage container SC to detect the humidity inside the storage container SC. The acceleration sensor GS is set in the storage container SC to detect vibrations and impacts applied to the storage container SC. The sensor unit 30A may include other sensors.

The sensor unit 30A of this embodiment includes a wireless communication device (not shown) for wireless communication with the anomaly detection unit 150. The sensor unit 30A may also include a communication device for wired communication with the anomaly detection unit 150.

The abnormality detection unit 150 prevents the occurrence of abnormal heat generation based on the monitoring results of factors that lead to the abnormal heat generation, detects an abnormal state occurring in the battery at an early stage of the occurrence of the abnormal heat generation, and implements measures against the abnormal heat generation based on the detection results of the abnormal state. The abnormality detection unit 150 is configured in the same manner as the monitoring module 50 described in the first embodiment. That is, the abnormality detection unit 150 includes a memory unit 51, a wireless communication unit 52, an internal resistance detection unit 53, a monitoring IC 54, etc.

The abnormality detection unit 150 executes the control process shown in FIG. 12 described in the first embodiment to prevent and detect abnormal heat generation at an early stage. In addition, the abnormality detection unit 150 executes the external notification process and battery protection process described in the first embodiment as measures against abnormal heat generation.

In the external notification process, a signal indicating the occurrence of an abnormal heat generation phenomenon is output to the notification device ND, and the occurrence of the abnormal heat generation phenomenon is notified to the outside via the notification device ND. In this external notification process, it is desirable to notify to the outside, for example, at least one of the sensor outputs of the temperature sensor 31, the humidity sensor HS, the acceleration sensor GS, and the position information of the battery module BM in which the abnormal heat generation phenomenon occurred. This is because it becomes easier to clarify the responsibility for the occurrence of the abnormal heat generation phenomenon. Note that the position information of the battery module BM can be information determined based on, for example, the radio wave strength of the signal emitted by the sensor unit 30A.

Otherwise, it is the same as the first embodiment. The battery transport device BSC of this embodiment can obtain the same effects as the first embodiment, which are achieved from a common configuration or an equivalent configuration to the first embodiment.

The battery transport device BSC of this embodiment also has the following features:

(1) The battery transport device BSC comprises a storage container SC, a factor monitoring unit that monitors factors that lead to an abnormal heat generation phenomenon in which the temperature of the battery continues to rise unintentionally, and an abnormality detection unit 150 that detects abnormalities in the battery. The abnormality detection unit 150 suppresses the occurrence of abnormal heat generation based on the monitoring results of the factor monitoring unit, detects an abnormal state that occurs in the battery at an early stage of the occurrence of the abnormal heat generation phenomenon, and implements measures against the abnormal heat generation phenomenon based on the detection result of the abnormal state. This makes it possible to implement effective heat countermeasures when transporting batteries, such as preventing the occurrence of abnormal heat generation phenomenon, and implementing measures from the early stage of occurrence in the unlikely event that an abnormal heat generation phenomenon does occur.

(Modification of the fourth embodiment)
In the fourth embodiment, the battery transport equipment BSC has been described in detail, but the battery transport equipment BSC is not the same as the one described above, and may be partially different from the one described above. Furthermore, the technical matters described in the fourth embodiment can be applied to equipment and systems other than the battery transport equipment BSC.

Other Embodiments
Representative embodiments of the present disclosure have been described above, but the present disclosure is not limited to the above-described embodiments and can be modified in various ways, for example, as described below.

The battery monitoring device 20 of the present invention is required to take measures against abnormal heat generation in the battery, but is not required to estimate the battery volume ratio SOH or detect the amount of lithium precipitation in a lithium ion battery.

In the above embodiment, the amount of lithium deposition and the internal resistance of the battery are monitored as factors that can lead to abnormal heat generation, but physical quantities other than these may also be monitored as factors that can lead to abnormal heat generation.

In the above embodiment, multiple processes are exemplified as countermeasures against abnormal heat generation, but some of these processes may be performed by the battery monitoring device 20. In addition, countermeasures against abnormal heat generation may be processes other than those described above.

In the above embodiment, examples of abnormal conditions occurring in the battery at the early stage of the occurrence of an abnormal heat generation phenomenon include abnormal pressure inside the sealed container 11, abnormal temperature of the battery, abnormal voltage of the battery, and abnormal gas inside the sealed container 11, but are not limited to these. Battery conditions other than these may also be detected as abnormal conditions occurring at the early stage of the occurrence of an abnormal heat generation phenomenon.

The battery monitoring device 20 described above includes a flexible printed circuit board FPC and an ASIC circuit, but is not limited to this. The flexible printed circuit board FPC and the ASIC circuit are not essential components of the battery monitoring device 20.

As in the above embodiment, it is desirable for the battery monitoring device 20 to correct the estimated amount of lithium deposition based on the battery temperature or parasitic resistance value, but this is not required.

As in the above embodiment, it is desirable for the battery monitoring device 20 to compare a predetermined battery state estimated from the amount of lithium deposition with a predetermined battery state estimated from other elements to diagnose the suitability of the deposition amount detection unit 37, but this is not essential.

In the above embodiment, the volumetric rate SOH is estimated based on the amount of lithium precipitation and the thickness of the SEI layer of the battery, but the volumetric rate SOH may be estimated based on other physical quantities. The battery monitoring device 20 may be configured to detect, for example, a deterioration state of the battery, including cracks in the positive electrode, and calculate the volumetric rate SOH based on the deterioration state.

As in the above embodiment, it is desirable that the battery monitoring device 20, together with the battery management device 60, be capable of configuring a battery management system BMS that manages the battery module BM, but this is not necessary. The same applies to the charging system BCS and the battery evaluation system BRS. The battery evaluation system BRS may be configured as one functional part in the battery management system BMS.

The object of monitoring by the battery monitoring device 20 is not limited to an on-board battery installed in a vehicle. The battery monitoring device 20 can also be used as a device for monitoring, for example, a stationary storage battery or a portable storage battery.

The battery monitoring device 20 basically monitors lithium ion batteries, but is not limited to this. Any battery that may have similar issues to lithium ion batteries can also be monitored. Note that the battery monitored by the battery monitoring device 20 does not have to be one in which multiple battery cells C are modularized.

The battery monitoring device 20 may be configured to be connected to the battery ECU 100 by wire rather than wirelessly. The battery monitoring device 20 is not limited to being completely identical to the one described above, and may be partially different from the one described above.

It goes without saying that in the above-described embodiments, the elements constituting the embodiments are not necessarily essential, except in cases where they are specifically stated as essential or where they are clearly considered essential in principle.

In the above-described embodiments, when numerical values such as the number, values, amounts, ranges, etc. of components of the embodiments are mentioned, they are not limited to the specific numbers, except when it is expressly stated that they are essential or when they are clearly limited to a specific number in principle.

In the above-described embodiments, when referring to the shapes, positional relationships, etc. of components, etc., there is no limitation to those shapes, positional relationships, etc., unless specifically stated otherwise or in principle limited to a specific shape, positional relationship, etc.

The control unit and the method of the present disclosure may be realized in a special-purpose computer provided by configuring a processor and memory programmed to execute one or more functions embodied in a computer program. The control unit and the method of the present disclosure may be realized in a special-purpose computer provided by configuring a processor with one or more dedicated hardware logic circuits. The control unit and the method of the present disclosure may be realized in one or more special-purpose computers configured by a combination of a processor and memory programmed to execute one or more functions and a processor configured with one or more hardware logic circuits. The computer program may also be stored in a computer-readable non-transient tangible recording medium as instructions executed by the computer.

[Features of the present disclosure]
The present disclosure has the following features.

[Disclosure 1]
A battery monitoring device for monitoring a chargeable/dischargeable battery,
A factor monitoring unit (37, 53) that monitors factors that lead to an abnormal heat generation phenomenon in which the temperature of the battery continues to increase unintentionally;
An abnormality detection unit (50, 150) that detects an abnormality in the battery,
The abnormality detection unit prevents the occurrence of the abnormal heat generation phenomenon based on the monitoring results of the factors, detects an abnormal condition occurring in the battery at an early stage of the occurrence of the abnormal heat generation phenomenon, and implements measures against the abnormal heat generation phenomenon based on the detection results of the abnormal condition.

[Disclosure 2]
The battery monitoring device according to Disclosure 1, wherein the abnormality detection unit monitors the factor and detects the abnormal state in parallel.

[Disclosure 3]
The battery monitoring device described in Disclosure 1 or 2, wherein the countermeasures include an external notification process that notifies the outside of the occurrence of the abnormal heat generation phenomenon, or a battery protection process by at least one of temperature adjustment control and charging/discharging control of the battery.

[Disclosure 4]
The battery monitoring device according to any one of claims 1 to 3, wherein the abnormality detection unit performs an extension process for extending a life of the battery according to a result of the monitoring.

[Disclosure 5]
the battery is a lithium ion battery,
The battery monitoring device according to any one of Disclosures 1 to 4, wherein the factors include at least one of lithium precipitation inside the battery and the internal resistance of the battery.

[Disclosure 6]
The battery includes a battery pack in which a plurality of battery cells are connected in series,
A battery monitoring device described in any one of Disclosures 1 to 5, wherein the abnormality detection unit identifies an abnormal one of the multiple battery cells as an abnormal cell based on at least one of the monitoring result and the detection result for each of the multiple battery cells.

[Disclosure 7]
The battery is housed inside a sealed container (11),
The battery monitoring device described in any one of Disclosures 1 to 6, wherein the abnormality detection unit is configured to detect at least one of the following abnormal conditions: an internal pressure abnormality of the sealed container, a temperature abnormality of the battery, a voltage abnormality of the battery, and a gas abnormality within the sealed container.

[Disclosure 8]
The battery monitoring device according to any one of Disclosures 1 to 7, wherein the factor monitoring unit or the abnormality detection unit includes an ASIC circuit having an algorithm for performing at least a part of the monitoring of the factors and the detection of the abnormal state.

[Disclosure 9]
A battery monitoring device as described in any one of Disclosures 1 to 8, wherein the abnormality detection unit is configured to determine the degree of deterioration of the battery based on the monitoring results, and to be able to notify an external party of the determination result of the degree of deterioration or the time to replace the battery estimated from the determination result.

[Disclosure 10]
A connection member (21) is provided to connect the battery and the abnormality detection unit,
The battery monitoring device according to any one of Disclosures 1 to 9, wherein the connection member includes a flexible printed circuit (FPC) on which a portion of the factor monitoring unit is mounted.

[Disclosure 11]
The battery is applied to a battery transport device (BSC) for transporting the battery in a container,
The battery monitoring device described in any one of Disclosures 1 to 10, wherein the abnormality detection unit (150) prevents the occurrence of the abnormal heat generation phenomenon based on the monitoring results of the factors during transportation of the battery, detects an abnormal state occurring in the battery at an early stage of the occurrence of the abnormal heat generation phenomenon, and implements measures against the abnormal heat generation phenomenon based on the detection results of the abnormal state.

[Disclosure 12]
A battery transport device for transporting a chargeable/dischargeable battery by a moving object, comprising:
A container (SC) in which the battery is housed;
A factor monitoring unit (37) for monitoring factors that lead to an abnormal heat generation phenomenon in which the temperature of the battery continues to rise unintentionally;
An abnormality detection unit (150) that detects an abnormality in the battery,
The abnormality detection unit prevents the occurrence of the abnormal heat generation phenomenon based on the monitoring results of the factors, detects an abnormal condition occurring in the battery at an early stage of the occurrence of the abnormal heat generation phenomenon, and implements measures against the abnormal heat generation phenomenon based on the detection results of the abnormal condition.

[Disclosure 13]
A battery monitoring method for monitoring a chargeable/dischargeable battery, comprising:
Monitoring factors that lead to an abnormal heat generation phenomenon in which the temperature of the battery continues to increase unintentionally;
detecting an abnormality in the battery;
A battery monitoring method in which detecting an abnormality in the battery includes preventing the occurrence of the abnormal heat generation phenomenon based on the monitoring results of the factors, and detecting an abnormal condition occurring in the battery at an early stage of the occurrence of the abnormal heat generation phenomenon and implementing measures against the abnormal heat generation phenomenon based on the detection results of the abnormal condition.

20 Battery monitoring device 37 Deposition amount detection unit (factor monitoring unit)
50 Monitoring module (anomaly detection section)
53 Internal resistance detection unit (factor monitoring unit)

Claims (13)

A battery monitoring device for monitoring a chargeable/dischargeable battery,
A factor monitoring unit (37, 53) that monitors factors that lead to an abnormal heat generation phenomenon in which the temperature of the battery continues to increase unintentionally;
An abnormality detection unit (50, 150) that detects an abnormality in the battery,
the abnormality detection unit prevents the abnormal heat generation phenomenon from occurring based on the monitoring result of the factors, detects an abnormal state occurring in the battery at an early stage of the occurrence of the abnormal heat generation phenomenon, and implements measures against the abnormal heat generation phenomenon based on the detection result of the abnormal state ;
the battery is a lithium ion battery,
The factors include an amount of lithium deposition inside the battery,
The factor monitoring unit includes a short circuit (371) that temporarily shorts both ends of the lithium ion battery to discharge it, and has a deposition amount detection unit (37) that calculates an estimate of the amount of lithium deposition based on a change in at least one of the current and the voltage when both ends of the lithium ion battery are shorted by the short circuit . The battery monitoring device according to claim 1, wherein the abnormality detection unit monitors the factors and detects the abnormal state in parallel. The battery monitoring device according to claim 1 or 2, wherein the countermeasures include an external notification process that notifies the outside of the occurrence of the abnormal heat generation phenomenon, or a battery protection process that involves at least one of temperature regulation control and charge/discharge control of the battery. The battery monitoring device according to claim 1 or 2, wherein the abnormality detection unit performs an extension process to extend the life of the battery according to the monitoring result. 3. The battery monitoring device according to claim 1, wherein the factors include the amount of lithium deposition and an internal resistance of the battery. The battery includes a battery pack in which a plurality of battery cells are connected in series,
The battery monitoring device according to claim 1 , wherein the abnormality detection unit identifies an abnormal one of the plurality of battery cells as an abnormal cell based on at least one of the monitoring result and the detection result for each of the plurality of battery cells. The battery is housed inside a sealed container (11),
The battery monitoring device of claim 1 or 2, wherein the abnormality detection unit is configured to detect at least one of the following abnormal conditions: an internal pressure abnormality of the sealed container, a temperature abnormality of the battery, a voltage abnormality of the battery, and a gas abnormality within the sealed container. The battery monitoring device according to claim 1 or 2, wherein the factor monitoring unit or the abnormality detection unit includes an ASIC circuit having an algorithm that performs at least a portion of the monitoring of the factors and the detection of the abnormal state. The battery monitoring device according to claim 1 or 2, wherein the abnormality detection unit is configured to determine the degree of deterioration of the battery based on the monitoring result and to be able to notify an external device of the result of the determination of the degree of deterioration or the time to replace the battery estimated from the result of the determination. A connection member (21) is provided to connect the battery and the abnormality detection unit,
The battery monitoring device according to claim 1 , wherein the connection member includes a flexible printed circuit (FPC) on which a part of the factor monitoring unit is mounted. The battery is applied to a battery transport device (BSC) for transporting the battery in a container,
3. The battery monitoring device of claim 1, wherein the abnormality detection unit (150) prevents the abnormal heat generation phenomenon from occurring based on the monitoring results of the factors during transportation of the battery, detects the abnormal state occurring in the battery at an early stage of the occurrence of the abnormal heat generation phenomenon, and implements measures against the abnormal heat generation phenomenon based on the detection results of the abnormal state. A battery transport device for transporting a chargeable/dischargeable battery by a moving object, comprising:
A container (SC) in which the battery is housed;
A factor monitoring unit (37) for monitoring factors that lead to an abnormal heat generation phenomenon in which the temperature of the battery continues to rise unintentionally;
An abnormality detection unit (150) that detects an abnormality in the battery,
the abnormality detection unit prevents the abnormal heat generation phenomenon from occurring based on the monitoring result of the factors, detects an abnormal state occurring in the battery at an early stage of the occurrence of the abnormal heat generation phenomenon, and implements measures against the abnormal heat generation phenomenon based on the detection result of the abnormal state ;
the battery is a lithium ion battery,
The factors include an amount of lithium deposition inside the battery,
The factor monitoring unit includes a short circuit (371) that temporarily shorts both ends of the lithium ion battery to discharge it, and has a deposition amount detection unit (37) that calculates an estimate of the amount of lithium deposition based on a change in at least one of the current and the voltage when both ends of the lithium ion battery are shorted by the short circuit . A battery monitoring method for monitoring a chargeable/dischargeable battery, comprising:
Monitoring factors that lead to an abnormal heat generation phenomenon in which the temperature of the battery continues to increase unintentionally;
detecting an abnormality in the battery;
Detecting an abnormality in the battery includes preventing the abnormal heat generation phenomenon from occurring based on the monitoring results of the factors, and detecting an abnormal state occurring in the battery at an early stage of the occurrence of the abnormal heat generation phenomenon and implementing measures against the abnormal heat generation phenomenon based on the detection results of the abnormal state ,
the battery is a lithium ion battery,
The factors include an amount of lithium deposition inside the battery,
The battery monitoring method, wherein monitoring the factors includes calculating an estimate of the amount of lithium deposition based on a change in at least one of a current and a voltage when both ends of the lithium ion battery are temporarily short-circuited and discharged .

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