JP6933176B2 - Server and battery management system - Google Patents

Description

The present disclosure relates to a battery information processing device, and more particularly to a technique for manufacturing an assembled battery by exchanging at least a part of a plurality of cells constituting the assembled battery mounted on a vehicle.

The assembled battery is composed of a plurality of secondary batteries. By combining a plurality of secondary batteries, a large-capacity assembled battery can be obtained. However, in order to use the assembled battery for a long period of time, maintenance of the assembled battery is required. Japanese Unexamined Patent Publication No. 2015-73427 (Patent Document 1) discloses a battery management system for maintenance of an assembled battery. In this battery management system, it is determined whether or not maintenance of the assembled battery is necessary based on the variation in the characteristics of a plurality of battery blocks included in the assembled battery, and if maintenance of the assembled battery is necessary, the assembly is performed. Notify the person concerned with the battery of the information related to the assembled battery. Each secondary battery constituting the assembled battery is also referred to as a "cell", a "cell", or the like, and hereinafter, each secondary battery is referred to as a "cell".

JP-A-2015-73427

Generally, when the cell of the assembled battery mounted on the vehicle is replaced, the cell is replaced with a cell having the same specifications (material, structure, etc.) as the cell before the replacement. Therefore, it is often replaced with a cell having the same performance as the cell before replacement. However, how to use the vehicle differs depending on the user. Therefore, it is not always appropriate to replace the cell with a cell having the same performance as the cell before replacement. For example, for users who use the vehicle in such a way that lithium is likely to precipitate on the electrode surface of the lithium-ion secondary battery mounted on the vehicle, the battery performance may deteriorate (battery capacity decreases, etc.) or the cell may be replaced. It may lead to an increase in frequency. The battery management system described in Patent Document 1 described above is useful in that maintenance of the assembled battery can be performed at an appropriate time, but a cell suitable for cell replacement from a plurality of types of cells (replacement cell). There is room for further improvement in order to be able to select.

The present disclosure has been made to solve such a problem, and an object thereof is battery information capable of providing information for selecting an appropriate replacement cell in consideration of the difference in vehicle usage for each user. It is to provide a processing device.

The battery information processing device of the present disclosure is a battery information processing device that processes information for manufacturing an assembled battery including a plurality of cells, and includes an acquisition unit and a generation unit. The cell is a lithium ion secondary battery. The above acquisition unit acquires the usage history information of the assembled battery used in the vehicle. In the vehicle, when a predetermined execution condition (hereinafter, may be referred to as “Li precipitation suppression condition”) is satisfied, a Li precipitation suppression process for suppressing lithium precipitation on the electrode surface of the cell is executed. The usage history information of the assembled battery includes the execution history of the Li precipitation suppressing process. The above generation unit uses the execution history of the Li precipitation suppression process to generate exchange information for selecting a suitable cell for cell exchange from the exchange cell. The exchange information indicates which of the cells classified by the above-mentioned predetermined index indicating the degree of resistance to lithium precipitation (hereinafter, may be referred to as "Li precipitation resistance index") is a compatible cell. ..

The above-mentioned lithium ion secondary battery is a secondary battery that charges and discharges using lithium as a charge carrier, and is a general lithium ion secondary battery (electrolyte type lithium) that uses a liquid electrolyte (for example, an organic solvent). It includes not only an ion secondary battery) but also an all-solid-state battery (all-solid-state lithium-ion secondary battery) using a solid electrolyte.

When an assembled battery is used in a vehicle, lithium may be deposited on the surface of an electrode (for example, a negative electrode) of a cell (lithium ion secondary battery) constituting the assembled battery. When lithium is deposited on the electrode surface of the cell, the cell capacity (the amount of electric power that can be stored in the cell) decreases. The likelihood of lithium precipitation on the electrode surface of the cell depends on how the assembled battery is used. How to use the assembled battery depends on how the user uses the vehicle. In a vehicle in which the Li precipitation suppression process is executed, the user's usage of the vehicle is reflected in the execution history of the Li precipitation suppression process. For example, in a vehicle that has been used so that lithium precipitation is likely to occur on the electrode surface of the cell (hereinafter, may be referred to as "first usage"), the Li precipitation suppression process is frequently executed, or Li The precipitation suppression treatment may be performed with high intensity (that is, with a large amount of suppression). On the other hand, in a vehicle that has been used so that lithium precipitation is less likely to occur on the electrode surface of the cell (hereinafter, may be referred to as "second usage"), compared with a vehicle that has been used in the first usage, The execution frequency and strength of the Li precipitation suppression treatment are reduced.

In the above battery information processing apparatus, exchange information is generated using the execution history of the Li precipitation suppression process. For this reason, in the vehicle used in the first manner, lithium on the electrode surface of the cell is manufactured for a long period of time by manufacturing the assembled battery in the cell having high lithium precipitation resistance (difficulty of lithium precipitation on the electrode surface of the cell). It is possible to suppress precipitation and maintain a high capacity of the assembled battery. Further, in the second usage, lithium precipitation on the electrode surface of the cell does not become a problem. For this reason, in the vehicle used in the second way, by manufacturing the assembled battery in a cell having an advantage other than lithium precipitation, the capacity of the assembled battery can be maintained high for a long period of time, and another merit can be obtained. It will be possible to enjoy it. For example, if a cell suitable for increasing the capacity is used in the manufacture of an assembled battery, a large capacity assembled battery can be obtained. Further, if an inexpensive cell is used for manufacturing an assembled battery, it is advantageous in terms of cost. As described above, according to the above-mentioned battery information processing device, it is possible to provide information (exchange information) for manufacturing an assembled battery by an appropriate replacement cell in consideration of the difference in how the vehicle is used for each user. become.

Note that "acquiring" usage history information (execution history of Li precipitation suppression processing, etc.) means generating and acquiring usage history information in the battery information processing device and externally (for example, a set) of the battery information processing device. This includes receiving and acquiring usage history information generated in a vehicle equipped with a battery, etc.).

Further, the battery information processing device may be a server that manages battery information, or may be a terminal different from such a server. When the battery information processing device is a terminal, for example, the terminal may acquire the usage history information acquired in the server from the server and generate the exchange information in the terminal.

An example of the Li precipitation suppressing process is the limitation of the charging power of the assembled battery. By limiting the charging power (input power) of the assembled battery, lithium is less likely to precipitate on the electrode surface of the cell. The execution condition of the Li precipitation suppressing process may be satisfied, for example, when the state of the assembled battery (temperature, current, SOC, etc.) reaches a predetermined state. Examples of the execution history of the Li precipitation suppression process used for generating the exchange information include the execution frequency and intensity (magnitude of the suppression amount) of the Li precipitation suppression process. Specific examples of the execution frequency of the Li precipitation suppression treatment include the ratio of the period during which the Li precipitation suppression treatment was executed to the unit period. The unit period may be specified by the number of times the vehicle has traveled (the number of trips), or may be specified by the mileage of the vehicle or the usage time of the assembled battery (elapsed time from the start of use).

An example of the Li precipitation resistance index is the amount of LiBOB (additive) in the electrolytic solution in the electrolytic solution type lithium ion secondary battery. As the amount of LiBOB increases, the lithium precipitation resistance tends to increase (that is, lithium tends to be less likely to precipitate on the electrode surface of the cell). The number of cell divisions (hereinafter, may be referred to as "cell divisions") classified according to the Li precipitation resistance index is arbitrary as long as it is 2 or more.

A suitable battery manufacturing support device used together with the above-mentioned battery information processing device in the manufacturing of an assembled battery is shown below.

A suitable battery production support device is a battery production support device for manufacturing an assembled battery by exchanging at least a part of a plurality of cells constituting the assembled battery with a compatible cell selected from replacement cells. It includes an acquisition unit that acquires exchange information generated by the battery information processing device, and a selection unit that selects a compatible cell according to the exchange information acquired by the acquisition unit. According to such a battery manufacturing support device, an appropriate replacement cell can be selected in consideration of the difference in how the vehicle is used for each user, and the assembled battery can be manufactured using the selected replacement cell.

Further, the assembled battery manufactured according to the exchange information generated by the above-mentioned battery information processing apparatus includes an appropriate exchange cell suitable for the usage of the user's vehicle. That is, such an assembled battery is suitable for the user.

According to the battery information processing apparatus of the present disclosure, it is possible to provide information for selecting an appropriate replacement cell in consideration of the difference in the usage of the vehicle for each user.

It is a figure which showed one aspect of the physical distribution from the collection of a battery pack to the manufacture and sale in the embodiment of this disclosure. It is a figure which showed the configuration example of the battery management system applied to the battery distribution model shown in FIG. It is a figure which showed the configuration of the vehicle, the management server, and the terminal of the battery pack manufacturer shown in FIG. 2 in detail. It is a figure which shows the relationship between the amount of lithium precipitation on the negative electrode surface of a lithium ion secondary battery, and the amount of capacity decrease of a lithium ion secondary battery based on the initial state. It is an execution frequency distribution of the Li precipitation suppression control measured in a vehicle used so that lithium precipitation is likely to occur on the negative electrode surface of the cell. It is the execution frequency distribution of the Li precipitation suppression control measured in the vehicle used so that the precipitation of lithium is less likely to occur on the negative electrode surface of the cell. It is a flowchart explaining the procedure of the process executed by the ECU of a vehicle. It is a flowchart explaining the procedure of the process executed by the management server. It is a figure for demonstrating the conforming cell which is shown by the rebuild information generated in the process of FIG. It is a figure which shows the relationship between the addition amount of LiBOB in a lithium ion secondary battery, the resistance of a negative electrode surface, and the lithium precipitation resistance. It is a figure for demonstrating the conforming cell which is shown by the rebuild information generated in the modification which classified the user's use of a vehicle into two categories. It is a flowchart explaining the procedure of the process executed by the management server in the modified example which classified the usage of a user's vehicle into two categories. It is a figure which showed the result of having evaluated the capacity retention rate before and after deterioration about the rebuilt product by an Example and the rebuilt product by a comparative example. It is a figure for demonstrating the conforming cell which is shown by the rebuild information generated in the modification which adopted the LiBOB addition amount, the negative electrode basis weight, and the negative electrode BET as a Li precipitation resistance index.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are designated by the same reference numerals, and the description thereof will not be repeated.

FIG. 1 is a diagram showing an aspect of physical distribution from collection to manufacturing / sales of a battery pack in the embodiment of the present disclosure. Hereinafter, the mode of distribution shown in FIG. 1 will be referred to as a “battery distribution model”. In the present disclosure, "manufacturing a battery pack" means manufacturing a battery pack by replacing at least a part of a plurality of cells included in the battery pack with replacement cells. The replacement cell is basically a reusable cell taken out of the recovered battery pack, but may be a new cell.

With reference to FIG. 1, this battery distribution model includes a collection company 31, an inspection company 32, a performance recovery company 33, a battery pack manufacturer 34, a dealer 35, a recycler 36, and a battery management system (vehicle) as described below. 10. It is constructed by the management server 20 etc.).

FIG. 2 is a diagram showing a configuration example of a battery management system applied to the battery distribution model shown in FIG. With reference to FIG. 2, the battery management system 1 includes a vehicle 10, a management server 20, terminals 41 to 45, and a communication network 50. The vehicle 10, the management server 20, and the terminals 41 to 45 are configured to be able to communicate with each other via a communication network 50 such as the Internet or a telephone line. The vehicle 10 is configured to be able to exchange information with the base station 51 of the communication network 50 by wireless communication. The terminals 41, 42, 43, 44, and 45 are terminals of a collection company 31, an inspection company 32, a performance recovery company 33, a battery pack manufacturer 34, and a store 35, respectively, as shown in FIG.

With reference to FIG. 1 again, the collection company 31 collects the used battery pack from the vehicles 60-1, 60-2, 60-3, .... Vehicles 60-1, 60-2, 60-3, ... Are equipped with battery packs 62-1, 62-2, 62-3, ..., Respectively, and each battery pack has a plurality of cells. Consists of including. Further, the collection company 31 disassembles the collected battery pack and takes out the cell from the battery pack. The cells may be taken out from the battery pack for each cell, or for each module in which several cells are grouped.

In this battery distribution model, an ID for identifying the cell is assigned to each cell, and the information of each cell is managed by the management server 20. Then, the collection company 31 transmits the ID of each cell taken out from the battery pack to the management server 20 using the terminal 41.

The inspector 32 inspects the performance of each cell collected by the collector 31. Specifically, the inspector 32 inspects the electrical properties of the recovered cell. For example, the inspector 32 inspects the electrical characteristics such as cell capacity, resistance value, OCV (Open Circuit Voltage), and SOC (State Of Charge). Then, the inspection company 32 separates the reusable cell and the non-reusable cell based on the inspection result, hands over the reusable cell to the performance recovery company 33, and the non-reusable cell. Will be handed over to the recycler 36. The inspection result of each cell is transmitted to the management server 20 using the terminal 42 of the inspection company 32.

The performance recovery company 33 performs a process for recovering the performance of the cell (replacement cell) that has been made reusable by the inspection company 32. As an example, the performance recovery company 33 recovers the capacity of the cell by discharging the cell to the over-discharged state or charging the cell to the over-charged state. The performance recovery process by the performance recovery company 33 may be omitted for the cells for which the performance deterioration is determined to be small in the inspection by the inspection company 32. The performance recovery result of each cell is transmitted to the management server 20 using the terminal 43 of the performance recovery company 33.

The battery pack manufacturer 34 manufactures the battery pack using the cells whose performance has been restored by the performance recovery manufacturer 33. In this embodiment, the battery pack manufacturer 34 acquires information for manufacturing the battery pack from the management server 20 using the terminal 44, and manufactures the battery pack according to the acquired information.

Specifically, in this embodiment, rebuild information for manufacturing a rebuilt product of the battery pack mounted on the vehicle 10 is generated in the management server 20 and transmitted to the terminal 44 of the battery pack manufacturer 34. According to the rebuild information, the battery pack manufacturer 34 replaces at least a part of the plurality of cells contained in the battery pack of the vehicle 10 with cells whose performance has been recovered by the performance recovery company 33 (replacement cells). Manufacture a rebuilt product of the battery pack of the vehicle 10.

The store 35 sells the battery pack manufactured by the battery pack manufacturer 34 for vehicles, or for stationary use that can be used in a house or the like. In this embodiment, the vehicle 10 is brought to the dealer 35, where the battery pack of the vehicle 10 is replaced with a rebuilt product manufactured by the battery pack manufacturer 34.

The recycler 36 dismantles the cells that have been made unreusable by the inspector 32, and recycles them for use as raw materials for new cells and other products.

The vehicle 10 is a vehicle on which a battery pack (not shown) is mounted and the battery pack is rebuilt in this battery distribution model (hereinafter, the vehicle 10 may be referred to as a “target vehicle”). ). As described above, in this embodiment, at least a part of the plurality of cells included in the battery pack mounted on the vehicle 10 is replaced with a replacement cell, and the battery pack for the vehicle 10 is rebuilt.

The details will be described later, but in general, the usage history information of the assembled batteries in the battery pack mounted on the vehicle 10 is transmitted from the vehicle 10 to the management server 20 and stored in the management server 20. Further, the management server 20 is a reusable cell included in the battery packs 62-1, 62-2, ... Collected from the vehicles 60-1, 60-2, ... equipped with the battery pack. Accumulate information.

When the user of the vehicle 10 (target vehicle) wishing to replace the battery pack hands over the vehicle 10 to the dealer 35, information for identifying the vehicle 10 is transmitted from the terminal 45 of the dealer 35 to the management server 20. The management server 20 refers to the stored usage history information of the assembled battery of the vehicle 10 and the information of the reusable cell, and rebuilds the battery pack to be mounted on the vehicle 10 to configure a rebuild product. Generate information. The generated rebuild information is transmitted from the management server 20 to the terminal 44 of the battery pack manufacturer 34, and the battery pack manufacturer 34 selects a cell based on the rebuild information from the reusable cells whose performance has been recovered. Then, a rebuilt product of the battery pack of the vehicle 10 is manufactured. The manufactured rebuilt product is delivered to the store 35 where the vehicle 10 is brought in, and the battery pack of the vehicle 10 is replaced with the rebuilt product at the store 35.

In the above, the collection company 31, the inspection company 32, the performance recovery company 33, the battery pack manufacturer, and the store 35 are separate companies from each other, but the classification of the companies is not limited to this. For example, the inspection company 32 and the performance recovery company 33 may be one company. Alternatively, the collection company 31 may be divided into a company that collects the battery pack and a company that disassembles the collected battery pack. In addition, the bases of the above-mentioned vendors and dealers are not limited. Each base of each trader and dealer may be separate, or a plurality of traders or dealers may be in the same base.

FIG. 3 is a diagram showing in detail the configurations of the vehicle 10, the management server 20, and the terminal 44 of the battery pack manufacturer 34 shown in FIG.

With reference to FIG. 3, the management server 20 includes an information processing device 210, a communication device 220, a recycled product database (DB) 230, and a battery information database (DB) 240.

The reused product DB 230 is a cell included in the used battery packs 62-1, 62-2, ... (FIG. 1) collected by the collection company 31 and reusable by the inspection company 32. Information (hereinafter referred to as "replacement cell information") is stored in association with an ID that identifies each cell. The replacement cell information includes initial cell information (for example, traceability data stored at the time of shipment) and used cell information. The cell traceability data includes an index indicating the degree of lithium precipitation resistance of each cell (BET specific surface area of electrode, grain amount, LiBOB addition amount, etc.). The used cell information is collected, for example, by performing a performance evaluation of each cell by an inspector 32, and includes the above-mentioned index indicating the degree of lithium precipitation resistance of each cell.

The battery information DB 240 stores information on the battery pack 110 mounted on the vehicle 10 (hereinafter, referred to as “target battery pack information”) in association with an ID that identifies the vehicle 10. The target battery pack information includes initial information of the battery pack 110 (for example, traceability data stored at the time of shipment) and information of the battery pack 110 periodically received from the vehicle 10 (for example, usage history information of the battery pack 110). including.

The information processing device 210 includes a CPU (Central Processing Unit), a memory, an input / output port for inputting / outputting various signals, and the like (none of which are shown). When the information processing device 210 receives the information for identifying the vehicle 10 for rebuilding the battery pack 110 from the terminal 45 of the store 35 by the communication device 220, the information processing device 210 reappears with the target battery pack information stored in the battery information DB 240. Using the replacement cell information stored in the used product DB 230, rebuild information for rebuilding the battery pack 110 is generated. Then, the information processing device 210 transmits the generated rebuild information to the terminal 44 of the battery pack manufacturer 34 by the communication device 220. The details of the specific processing for generating the rebuild information will be described later.

The vehicle 10 includes a battery pack 110, a battery monitoring unit 112, a power control unit (PCU: Power Control Unit) 120, a motor generator (MG: Motor Generator) 130, a drive wheel 140, and an electronic control unit (ECU:). It includes an Electronic Control Unit) 150, a storage unit 160 (for example, a non-volatile memory), a communication device 170, and a communication line 180. The ECU 150, the storage unit 160, and the communication device 170 are connected by a communication line 180, and are configured to be able to send and receive information to and from each other.

The vehicle 10 is configured to be capable of traveling by converting the electric power stored in the battery pack 110 into power. The vehicle 10 may be an electric vehicle having no engine (internal combustion engine), or a hybrid vehicle having an engine (not shown) and capable of traveling by the power output from the engine. good. The electric power stored in the battery pack 110 is converted into power for driving the drive wheels 140 by the MG 130.

The battery pack 110 is configured to include an assembled battery composed of a plurality of cells, for example, an assembled battery in which a plurality of lithium ion secondary batteries are connected in series and / or in parallel. The details of the configuration of each cell (lithium ion secondary battery) included in the assembled battery will be described later.

The battery monitoring unit 112 includes various sensors and is configured to monitor the state of the battery pack 110. The battery monitoring unit 112 includes, for example, a voltage sensor, a current sensor, and a temperature sensor. The voltage sensor detects the voltage of the assembled battery in the battery pack 110 and outputs the detected value to the ECU 150. The current sensor detects the current of the assembled battery in the battery pack 110 and outputs the detected value to the ECU 150. The temperature sensor detects the temperature of the assembled battery in the battery pack 110 and outputs the detected value to the ECU 150. The ECU 150 can detect the state (temperature, current, SOC, etc.) of the assembled battery based on the output of the battery monitoring unit 112. The SOC indicates the remaining amount of electricity stored, and for example, the ratio of the current amount of electricity stored to the amount of electricity stored in the fully charged state is expressed by 0 to 100%. The SOC calculation method is arbitrary, and a method based on current value integration (Coulomb count), a method based on open circuit voltage (OCV) estimation, or the like can be adopted.

The MG 130 is a rotary electric machine, for example, a three-phase AC motor generator. The MG 130 is driven by the PCU 120 to rotate the drive wheels 140. Further, the MG 130 can also generate regenerative power generation when the vehicle 10 is braked or the like. The electric power generated by the MG 130 is rectified by the PCU 120 and charged into the battery pack 110.

The PCU 120 includes an inverter and a converter (neither of them is shown), and drives the MG 130 according to a drive signal from the ECU 150. The PCU 120 converts the DC power supplied from the battery pack 110 into AC power and supplies it to the MG 130 during the power running drive of the MG 130, and the MG 130 generates electricity during the regenerative driving of the MG 130 (such as when braking the vehicle 10). The electric power is rectified and supplied to the battery pack 110.

The ECU 150 includes a CPU, a memory, an input / output port, and the like (none of them are shown). The ECU 150 controls each device so that the vehicle 10 is in a desired state based on the signal received from each sensor and the map and program stored in the memory. By controlling the PCU 120 and the like, the ECU 150 executes running control of the vehicle 10 and charge / discharge control of the battery pack 110.

The ECU 150 controls the input / output power of the battery pack 110 based on the input limit Win indicating the upper limit value of the charging power of the battery pack 110 and the output limit Wout indicating the upper limit value of the discharge power of the battery pack 110. It is composed. The ECU 150 executes the input power limiting process to the battery pack 110 so that the input power to the battery pack 110 does not exceed the input limit Win. Further, the ECU 150 executes the process of limiting the output power from the battery pack 110 so that the output power from the battery pack 110 does not exceed the output limit Wout. These restriction processes are performed by controlling the PCU 120 and the like. The input limit Win and the output limit Wout are stored in, for example, the storage unit 160. The respective numerical values of the input limit Win and the output limit Wout can be changed by the ECU 150.

When the Li precipitation suppression control described later is not executed, the limit value SWin is set to the input limit Win. On the other hand, when the Li precipitation suppression control is executed, a limit value cWin smaller than the limit value SWin is set as the input limit Win. The smaller the value of the input limit Win, the stronger the limit of the charging power for the battery pack 110 (that is, the larger the limit amount).

In this embodiment, the following electrolyte-type lithium-ion secondary battery is adopted as a cell for forming the assembled battery in the battery pack 110 mounted on the vehicle 10.

The cell is configured by accommodating an electrode body inside, for example, a square battery case. The electrode body is formed by laminating a positive electrode and a negative electrode via a separator and winding the laminated body. The electrolytic solution is held in a positive electrode, a negative electrode, a separator and the like.

The positive electrode includes a positive electrode current collector (for example, aluminum foil) and a positive electrode active material layer. For example, by applying a positive electrode mixture containing a positive electrode active material, a binder, and a conductive auxiliary agent to the surface of the positive electrode current collector, positive electrode active material layers are formed on both sides of the positive electrode current collector. Further, the negative electrode includes a negative electrode current collector (for example, a copper foil) and a negative electrode active material layer. For example, by applying a negative electrode mixture containing a negative electrode active material, a binder, and a conductive auxiliary agent to the surface of the negative electrode current collector, negative electrode active material layers are formed on both sides of the negative electrode current collector.

As the positive electrode, the negative electrode, the separator, and the electrolytic solution, the configurations and materials known as the positive electrode, the negative electrode, the separator, and the electrolytic solution of the lithium ion secondary battery can be used, respectively. As an example, a lithium-containing nickel-cobalt-manganese composite oxide (a ternary material in which a part of lithium cobalt oxide is replaced with nickel and manganese) can be used as the positive electrode active material. A carbon-based material (for example, soft carbon or hard carbon) can be used as the negative electrode active material. Polyolefin (for example, polyethylene or polypropylene) can be used as the separator. The electrolytic solution contains an organic solvent (for example, a mixed solvent of DMC (dimethyl carbonate), EMC (ethyl methyl carbonate) and EC (ethylene carbonate)), a lithium salt (for example, LiPF ₆ ), and LiBOB (lithium bis (for example). A solution containing oxalate) borate) can be used.

The configuration of the cell (lithium ion secondary battery) is not limited to the above, and can be changed according to the applicable vehicle configuration, application, and the like. For example, the electrode body may have a laminated structure instead of a wound structure. Further, the battery case is not limited to the square type, and a cylindrical type or a laminated type battery case can also be adopted. Further, instead of the electrolytic solution, a polymer-based electrolyte may be used, or an inorganic-based solid electrolyte such as an oxide-based or sulfide-based electrolyte may be used.

In a lithium ion secondary battery, lithium serves as a charge carrier. More specifically, lithium is inserted into the negative electrode active material when the cell is charged, and lithium is desorbed from the negative electrode active material when the cell is discharged. When the cell is repeatedly charged and discharged, lithium may be deposited on the surface of the negative electrode of the cell. In particular, charging at a high rate, charging from a high charging state (high SOC), continuous charging for a long time, and charging in a state of high battery resistance (for example, a state where the battery temperature is low) are lithium on the negative electrode surface of the cell. Tends to promote precipitation.

When lithium is deposited on the surface of the negative electrode of the cell, the cell capacity is reduced. FIG. 4 is a diagram showing the relationship between the amount of lithium deposited on the negative electrode surface of the lithium ion secondary battery and the amount of decrease in capacity of the lithium ion secondary battery based on the initial state (immediately after the start of use).

With reference to FIG. 4, the amount of lithium deposited on the negative electrode surface of the lithium ion secondary battery and the amount of decrease in capacity of the lithium ion secondary battery based on the initial state have a relationship as shown by the straight line k10. That is, the larger the amount of lithium deposited on the surface of the negative electrode, the lower the battery capacity.

In the vehicle 10, when lithium precipitation occurs on the negative electrode surface of the cells constituting the assembled battery in the battery pack 110 and the capacity of the assembled battery decreases, the vehicle 10 travels using only the electric power of the battery pack 110. The possible distance) decreases.

In the vehicle 10, the ECU 150 is configured to execute Li precipitation suppression control in order to suppress lithium precipitation on the negative electrode surface of the cell. When a predetermined Li precipitation suppression condition is satisfied, the Li precipitation suppression control is executed by the ECU 150. By executing the Li precipitation suppression control, the limit value cWin for suppressing lithium precipitation on the negative electrode surface of the cell is set to the input limit Win. By setting the limit value cWin in the input limit Win, the charging power (input power) of the cell is limited to the power at which lithium precipitation does not occur (= limit value cWin). The Li precipitation suppression control according to this embodiment corresponds to an example of the “Li precipitation suppression treatment” according to the present disclosure.

The Li precipitation suppression condition is determined by, for example, the SOC of the assembled battery, the temperature of the assembled battery, and the integrated current value due to continuous charging of the assembled battery. When the limit value SWin is set in the input limit Win, the Li precipitation suppression condition is satisfied when lithium precipitation can occur, and when the lithium precipitation does not occur even when the limit value SWin is set in the input limit Win, Li The precipitation suppression condition is not satisfied. For example, in an assembled battery, when charging is performed at a high rate, charging from a high SOC, continuous charging for a long time, or charging in a low temperature state, lithium is likely to be deposited on the negative electrode surface of the cell. , Li precipitation suppression condition is satisfied. When the Li precipitation suppression condition is satisfied, the ECU 150 executes the Li precipitation suppression control to strengthen the limitation of the charging power for the battery pack 110 and suppress the lithium precipitation on the negative electrode surface of the cell.

The limit value cWin may be changed according to the state of the assembled battery. For example, information indicating the relationship between the SOC of the assembled battery, the temperature of the assembled battery, the integrated current value due to continuous charging of the assembled battery, and the limit value cWin (hereinafter referred to as "cWin acquisition information") is tested in advance. It may be obtained by the above and stored in the storage unit 160. Then, the ECU 150 refers to the cWin acquisition information and performs Li precipitation suppression control with a limit value cWin obtained based on the SOC of the assembled battery, the temperature of the assembled battery, and the current integrated value due to continuous charging of the assembled battery. You may do it. The cWin acquisition information may be a map, a table, a mathematical formula, or a model. Further, the cWin acquisition information may be configured by combining a plurality of maps and the like.

By the way, how to use the vehicle (and by extension, how to use the assembled battery mounted on the vehicle) differs depending on the user. The likelihood of lithium precipitation on the negative electrode surface of the cell depends on how the assembled battery is used. If the assembled battery is rebuilt without considering the difference in how the vehicle is used by each user, it is not always possible to obtain a rebuilt product that suits the user. For example, for a user who uses a vehicle in which lithium precipitation is likely to occur on the negative electrode surface of the cell, the battery performance is lowered (battery capacity is lowered, etc.), the execution frequency of the Li precipitation suppression control is increased, and the cell is replaced. It may lead to an increase in frequency.

Therefore, in the battery management system 1 according to this embodiment, the information processing device 210 (battery information processing device) is configured to generate rebuild information (exchange information) using the execution history of the Li precipitation suppression control. .. The execution history of the Li precipitation suppression control reflects the user's usage of the vehicle 10.

FIG. 5 shows an execution frequency distribution of Li precipitation suppression control measured in one run in a vehicle in which lithium is likely to precipitate on the negative electrode surface of the cell (first usage). FIG. 6 shows an execution frequency distribution of Li precipitation suppression control measured in one run in a vehicle in which lithium is less likely to precipitate on the negative electrode surface of the cell (second usage).

In FIGS. 5 and 6, the “Win limit amount” on the horizontal axis indicates the charging power of the cell limited by executing the Li precipitation suppression control, and more specifically, the limit value SWin and the limit value. It is the difference (absolute value) from the value cWin. When the Li precipitation suppression control is executed, the Win limit amount becomes larger than 0. A large Win limit amount in the Li precipitation suppression control means that the charge power limit for the battery pack 110 is strong. The "frequency" on the vertical axis indicates the ratio (relative frequency) of the frequency for each Win limit amount to the total number of data acquired in one run (total frequency including the frequency of Win limit amount 0). By periodically counting (integrating) the frequency for each Win limit amount, the frequency for each Win limit amount can be obtained. Then, the relative frequency is obtained by dividing the obtained frequency by the total number of data (total of the frequencies).

With reference to FIGS. 5 and 6, the frequency of the region where the Win limit amount is larger than 0 indicates the execution frequency of the Li precipitation suppression control. The area S1 in FIG. 5 and the area S2 in FIG. 6 indicate the cumulative relative frequency of the region where the Win limit amount is larger than 0 (that is, the ratio of the period during which the Li precipitation suppression control was executed in one run). ing. As shown in FIGS. 5 and 6, the area S1 (integral value of the line k1) is larger than the area S2 (integral value of the line k2).

Further, the peak frequency value D1 of the frequency distribution shown by the line k1 is larger than the peak frequency value D2 of the frequency distribution shown by the line k2. Further, in the frequency distribution shown by the line k1, the execution frequency of the Li precipitation suppression control in the region where the Win limit amount is large is higher than that in the frequency distribution shown by the line k2.

As described above, in a vehicle in which lithium precipitation is likely to occur (first usage), the Li precipitation suppression control is frequently executed, or the Li precipitation suppression control has a high intensity (that is, a large Win limit amount). It will be executed. On the other hand, in the vehicle in which lithium precipitation is unlikely to occur (second usage), the execution frequency and intensity of the Li precipitation suppression control are lower than those in the vehicle in which the first usage is used. Therefore, based on the execution history of the Li precipitation suppression control, it is possible to determine the likelihood of lithium precipitation depending on how the user uses the vehicle 10. For example, in the execution frequency distribution of the Li precipitation suppression control as shown in FIGS. 5 and 6, when the cumulative relative frequency in the region where the Win limit amount is larger than 0 is large, the vehicle 10 is used in such a way that lithium precipitation is likely to occur. Can be determined to have been used. Further, even when the Win limit frequency Dw (see FIG. 8) in all traveling described later is large, it can be determined that the vehicle 10 has been used in such a way that lithium precipitation is likely to occur.

With reference to FIG. 3 again, the ECU 150 of the vehicle 10 generates usage history information of the battery pack 110 and stores it in the storage unit 160, and periodically reads out the usage history information of the battery pack 110 from the storage unit 160 for communication. It is transmitted to the management server 20 by the device 170. The management server 20 receives the usage history information of the battery pack 110 by the communication device 220. The usage history information of the battery pack 110 sent from the vehicle 10 includes the execution history of the Li precipitation suppression control. The information processing device 210 generates rebuild information using the execution history of the Li precipitation suppression control acquired from the vehicle 10. Then, the management server 20 transmits the generated rebuild information to the terminal 44 of the battery pack manufacturer 34 by the communication device 220. The battery pack manufacturer 34 selects a compatible cell from the replacement cells according to the rebuild information acquired from the management server 20, and manufactures a rebuilt product of the battery pack 110 using the compatible cell.

The information processing device 210 uses the execution history of the Li precipitation suppression control to determine the susceptibility of lithium precipitation to the user's usage of the vehicle 10, and generates rebuild information based on the determination result. The rebuild information generated by the information processing apparatus 210 indicates which of the cells classified by the Li precipitation resistance index indicating the degree of lithium precipitation resistance is a compatible cell. A cell having a higher resistance to lithium precipitation is selected as a suitable cell as the usage is such that lithium precipitation is more likely to occur.

The terminal 44 (battery manufacturing support device) of the battery pack manufacturer 34 includes a communication device 71, a control unit 72, and a display unit 73. The communication device 71 acquires the rebuild information from the management server 20. The control unit 72 selects a conforming cell from the replacement cells according to the acquired rebuild information, and causes the display unit 73 to display the information of the selected conforming cell. The battery pack manufacturer 34 manufactures a rebuilt product of the battery pack 110 of the vehicle 10 based on the information of the matching cell displayed on the display unit 73.

For example, when a cell is classified into two cell categories according to the Li precipitation resistance index, a cell category having high lithium precipitation resistance (hereinafter referred to as "first cell category") and a cell category having low lithium precipitation resistance (hereinafter referred to as "first cell category") are used. The cells are classified according to which one they belong to (referred to as "second cell division"). Then, when it is determined from the execution history of the Li precipitation suppression control regarding the usage of the user's vehicle 10 that lithium precipitation is likely to occur, the rebuild information indicating that the cell belonging to the first cell category is a conforming cell is processed. Generated by device 210. By manufacturing the assembled battery in a cell having high lithium precipitation resistance according to such rebuild information, it is possible to suppress lithium precipitation on the negative electrode surface of the cell for a long period of time and maintain a high capacity of the assembled battery. Further, when it is determined from the execution history of the Li precipitation suppression control regarding the usage of the user's vehicle 10 that lithium precipitation is unlikely to occur, the rebuild information indicating that the cell belonging to the second cell category is a conforming cell is processed. Generated by device 210. By manufacturing the assembled battery in the cell belonging to the second cell category according to such rebuild information, it becomes possible to enjoy yet another merit while maintaining the capacity of the assembled battery high for a long period of time. For example, if the cell belonging to the second cell category is a cell suitable for increasing the capacity, a large-capacity assembled battery can be obtained by manufacturing the assembled battery with such a cell. Further, if the cell belonging to the second cell category is a cell having a low internal resistance, it is possible to improve the drivability (drivability, power performance, etc.) of the vehicle 10. Further, if the cell belonging to the second cell category is an inexpensive cell, manufacturing the assembled battery with such a cell is advantageous in terms of cost. As described above, according to the information processing device 210, it is possible to provide rebuild information for manufacturing the assembled battery by an appropriate replacement cell in consideration of the difference in usage of the vehicle 10 for each user.

FIG. 7 is a flowchart illustrating a processing procedure executed by the ECU 150 of the vehicle 10. The process shown in this flowchart is executed while the vehicle 10 is running. More specifically, it is started by turning on the ignition switch (not shown) of the vehicle 10.

With reference to FIG. 7, the ECU 150 acquires the Win limit amount in the Li precipitation suppression control (step S10). The difference (absolute value) between the limit value cWin used in the Li precipitation suppression control during execution and the input limit Win value (= limit value SWin) when the Li precipitation suppression control is not executed is the Win limit. Corresponds to the amount. When the Li precipitation suppression control is not executed, the Win limit amount becomes 0.

Next, the ECU 150 updates the Win limit frequency distribution in the storage unit 160 according to the Win limit amount acquired in step S10 (step S20). More specifically, in the Win limit frequency distribution, a plurality of sections (classes) are provided on the horizontal axis according to the magnitude of the Win limit amount, and the vertical axis indicates the frequency for each section provided on the horizontal axis. show. In step S20, the frequency of the section corresponding to the magnitude of the Win limit amount acquired in step S10 is added (counted up) by 1.

In step S30, the ECU 150 determines whether or not the running of the vehicle 10 has been completed. More specifically, when the ignition switch is turned off, it is determined that the vehicle 10 has finished running. That is, in this embodiment, the period from the time when the ignition switch is turned on (at the start of running) to the time when the ignition switch is turned off (at the end of running) corresponds to one running.

While it is determined in step S30 that the running of the vehicle 10 has not been completed (NO in step S30), the processes of steps S10 to S20 are repeatedly executed in a predetermined calculation cycle. By repeatedly executing the processes of steps S10 to S20, a frequency distribution (that is, a Win limit frequency distribution) indicating the frequency of occurrence for each Win limit amount is created and stored in the storage unit 160.

On the other hand, when it is determined in step S30 that the running of the vehicle 10 has been completed (YES in step S30), the ECU 150 controls Li precipitation suppression in one running (that is, a period from the start of running to the end of running). The ratio of the period during which the above was executed (hereinafter, may be referred to as "Win limit frequency Dx in one run" or simply "Dx") is obtained and stored in the storage unit 160 (step S40). At the time when it is determined in step S30 that one run is completed (at the end of the run), the Win limit frequency distribution created in the one run is stored in the storage unit 160. In this Win limit frequency distribution, the cumulative frequency in the region where the Win limit amount is larger than 0 (cumulative execution frequency of Li precipitation suppression control) is the total frequency including the frequency with the Win limit amount 0 (all data acquired in one run). By dividing by (number), the Win limit frequency Dx in one run can be obtained.

The ECU 150 stores the usage history information of the battery pack 110 (and by extension, the assembled battery) obtained in the above one run in the storage unit 160 (step S50). The usage history information of the battery pack 110 includes the Win limit frequency distribution created in steps S10 to S20 and the number of data thereof (total number of data acquired in one run) and the Win limit frequency in one run acquired in step S40. Includes with Dx. The Win limit frequency distribution, the number of data thereof, and the Win limit frequency Dx in one run correspond to an example of the "execution history of the Li precipitation suppression process" according to the present disclosure. Further, the usage history information of the battery pack 110 may further include the integrated mileage of the vehicle 10 and the usage time of the battery pack 110.

Then, the ECU 150 reads the usage history information of the battery pack 110 stored in the storage unit 160 from the storage unit 160 and transmits it to the management server 20 by the communication device 170 (step S60). The usage history information of the battery pack 110 (Win limit frequency Dx in one run, etc.) transmitted from the vehicle 10 to the management server 20 is stored in the battery information DB 240 (FIG. 3). The ECU 150 transmits the usage history information of the battery pack 110 to the management server 20 each time one run is completed. However, the timing is not limited to this, and the timing at which the ECU 150 transmits the usage history information of the battery pack 110 to the management server 20 is arbitrary. The data of a plurality of runs may be collectively transmitted to the management server 20. The data of the plurality of runs may be distinguished for each run, such as the first run, the second run, and so on.

FIG. 8 is a flowchart illustrating a procedure of processing executed by the management server 20. The process shown in this flowchart is executed by transmitting information for identifying the vehicle 10 (target vehicle) for which the battery pack 110 is to be replaced from the terminal 45 of the store 35 to the management server 20.

With reference to FIG. 8, the management server 20 (information processing device 210) receives the above information of the target vehicle (vehicle 10) from the terminal 45 of the store 35 (step S110). Next, the management server 20 acquires the usage history information of the assembled battery (battery pack 110) of the target vehicle (vehicle 10) from the battery information DB 240 (step S120). That is, the management server 20 acquires the usage history information of the assembled battery (battery pack 110) of the target vehicle (vehicle 10) specified by the information received from the terminal 45 from the battery information DB 240.

Next, the management server 20 uses the usage history information (Dx, etc. for each run) of the battery pack 110 of the vehicle 10 acquired from the battery information DB 240 to execute the Li precipitation suppression control during the entire running period of the vehicle 10. The ratio of the period (hereinafter, may be referred to as “Win limit frequency Dw in all running” or simply “Dw”) is acquired (step S130).

The Win limit frequency Dw in all runs is, for example, a value obtained by calculating the execution frequency of Li precipitation suppression control per run using data of all runs (more specifically, execution history of Li precipitation suppression process). More specifically, the Win limit frequency Dw in all runs is, for example, the average value of Dx in all runs. However, the present invention is not limited to this, and the median value of Dx of all runs may be used instead of the average value of Dx of all runs. Further, the Win limit frequency Dw in all the runs may be a value obtained by dividing the cumulative execution frequency of the Li precipitation suppression control in all the runs by the total number of data acquired in all the runs.

In steps S141 and S142, the management server 20 is in any of the cells A to C described below as a suitable cell suitable for rebuilding (cell replacement) based on the Win limit frequency Dw in all the runs acquired in step S130. Determine if there is. Then, in steps S151 to S153, any of cells A to C is selected, and rebuild information for performing rebuild in the selected cell is generated.

FIG. 9 is a diagram for explaining the conforming cell indicated by the rebuild information generated in steps S151 to S153. In this embodiment, the cells are classified into three cell categories (cell categories A to C) according to the Li precipitation resistance index, and the rebuild information indicates which cell category the cell belongs to is a compatible cell. In this embodiment, the amount of LiBOB (additive) in the electrolytic solution of the lithium ion secondary battery (hereinafter referred to as "LiBOB addition amount") is adopted as a Li precipitation resistance index. It is determined that the larger the amount of LiBOB added to the cell, the higher the lithium precipitation resistance of the cell. Hereinafter, the cells belonging to the cell categories A, B, and C will be referred to as cells A, B, and C, respectively.

Cell A is a cell that satisfies the requirement that the amount of LiBOB added is large (large). Cell B is a cell that satisfies the requirement that the amount of LiBOB added is medium (standard). Cell C is a cell that satisfies the requirement that the amount of LiBOB added is small (small). When arranged in ascending order of the amount of LiBOB added, cells C, B, and A are obtained. The numerical range of the amount of LiBOB added in each cell category can be arbitrarily set as long as this relationship is satisfied.

In addition to the requirements for each cell category regarding the amount of LiBOB added, common requirements may be set for cell categories A to C. For example, a predetermined part of the cell is formed of a material corresponding to the cell constituting the assembled battery in the battery pack 110 (for example, the negative electrode active material is a carbon-based material, and the electrolytic solution is an organic solvent and lithium. It is a solution containing a salt and LiBOB), which may be a common requirement for cell categories A to C.

The inventor of the present application has found that the larger the amount of LiBOB added to the lithium ion secondary battery, the more difficult it is for lithium to precipitate on the negative electrode surface of the lithium ion secondary battery. Specifically, when a film derived from an electrolytic solution is formed on the surface of the negative electrode of a lithium ion secondary battery, the electrical resistance (hereinafter, simply referred to as “resistance”) on the surface of the negative electrode increases. Since lithium precipitation tends to occur in the high resistance portion of the negative electrode surface, an increase in resistance on the negative electrode surface promotes lithium precipitation. The inventor of the present application has found that the formation of an electrolytic solution-derived film on the negative electrode can be suppressed by increasing the amount of LiBOB added. Even if a LiBOB-derived film is formed on the surface of the negative electrode, the increase in resistance on the surface of the negative electrode is small. Therefore, by increasing the amount of LiBOB added, the increase in resistance on the surface of the negative electrode is suppressed and the precipitation of lithium on the surface of the negative electrode is suppressed.

FIG. 10 is a diagram showing the relationship between the amount of LiBOB added in the lithium ion secondary battery, the resistance on the surface of the negative electrode, and the lithium precipitation resistance (Li precipitation resistance). As shown by the line k20 with reference to FIG. 10, as the amount of LiBOB added is increased, the resistance of the negative electrode surface tends to decrease and the lithium precipitation resistance tends to increase. When each cell is used under the same conditions for the same period, the lower the lithium precipitation resistance, the larger the amount of lithium precipitation on the negative electrode surface. Therefore, the lower the lithium precipitation resistance of a cell, the greater the amount of decrease in cell capacity due to lithium precipitation.

Based on the above principle, it is considered that the lithium precipitation resistance increases as the amount of LiBOB added increases. When cells A to C shown in FIG. 9 are arranged in order from the one having the highest lithium precipitation resistance, cell A (Li precipitation resistance: high), cell B (Li precipitation resistance: medium), and cell C (Li precipitation resistance: low). It becomes.

With reference to FIG. 8 again, in step S141, the management server 20 determines whether or not the Dw acquired in step S130 is larger than the threshold value Th2. The threshold Th2 can be set based on, for example, market analysis data. In this embodiment, the threshold Th2 is set to 50%. Hereinafter, the threshold value Th2 may be simply referred to as "Th2".

When it is determined that Dw is larger than Th2 (YES in step S141), the management server 20 generates rebuild information for performing rebuild in cell A (FIG. 9) (step S151). Specifically, the management server 20 refers to the replacement cell information (initial cell information or cell information after use) stored in the reused product DB 230, and generates a rebuilt product for the cell used for rebuilding. Select as many as you need to do. At this time, the cell corresponding to cell A is preferentially selected. Preferably, only the cell corresponding to cell A is selected. As described above, in step S151, rebuild information indicating that cell A is a conforming cell is generated.

On the other hand, if it is determined in step S141 that Dw is Th2 or less (NO in step S141), the management server 20 determines whether or not the Dw acquired in step S130 is larger than the threshold Th1 (step). S142). The threshold value Th1 is a numerical value smaller than Th2 and can be set based on, for example, market analysis data. In this embodiment, the threshold Th1 is set to 5%. Hereinafter, the threshold value Th1 may be simply referred to as "Th1".

When it is determined that Dw is larger than Th1 (YES in step S142), the management server 20 generates rebuild information for performing rebuild in cell B (FIG. 9) (step S152). Specifically, the management server 20 refers to the replacement cell information stored in the reused product DB 230 and selects as many cells as necessary for generating the rebuilt product. At this time, the cell corresponding to cell B is preferentially selected. Preferably, only the cell corresponding to cell B is selected. As described above, in step S152, rebuild information indicating that cell B is a conforming cell is generated.

On the other hand, if it is determined in step S142 that Dw is Th1 or less (NO in step S142), the management server 20 generates rebuild information for performing rebuild in cell C (FIG. 9) (step S153). Specifically, the management server 20 refers to the replacement cell information stored in the reused product DB 230 and selects as many cells as necessary for generating the rebuilt product. At this time, the cell corresponding to cell C is preferentially selected. Preferably, only the cell corresponding to cell C is selected. As described above, in step S153, rebuild information indicating that cell C is a conforming cell is generated.

In steps S151 to S153, the management server 20 refers to the reused product DB 230, and the inventory of cells corresponding to the conforming cells (S151: cell A, S152: cell B, S153: cell C) is insufficient. If it is determined that there is, another cell may be selected based on a predetermined criterion to generate rebuild information, or information indicating that the number of conforming cells is insufficient is added to the rebuild information. You may.

Further, in steps S151 to S153, when the management server 20 refers to the reused product DB 230 and determines that the inventory of the cell corresponding to the conforming cell is sufficient, the cell corresponding to the conforming cell is selected. , Cells (cells used for rebuilding) may be randomly selected, or cells that meet predetermined requirements (for example, requirements considering the user's request) may be preferentially selected.

Then, when the rebuild information is generated in any of steps S151 to S153, the management server 20 transmits a rebuild product generation command according to the generated rebuild information to the terminal 44 of the battery pack manufacturer 34 (step S160). .. As a result, the battery pack manufacturer 34 produces a rebuilt product of the battery pack 110 mounted on the vehicle 10. A rebuilt product that follows such rebuild information has characteristics suitable for the user of the vehicle 10. Further, the management server 20 transmits the generated rebuild information to the terminal 45 of the store 35 to which the vehicle 10 has been delivered (step S170).

The timing of manufacturing the assembled battery (replacement of at least a part of the assembled battery) is arbitrary, and may be the time of purchasing a new car (replacement of the vehicle 10) or the time of purchasing a new battery pack. However, it may be the timing of regular maintenance. Further, the management server 20 obtains an appropriate cell replacement timing based on the usage history information of the battery pack 110 (for example, the integrated mileage of the vehicle 10, the usage time of the battery pack 110, etc.), and when that timing is reached. The user may be notified.

In the battery management system 1 according to the above embodiment, the information processing device 210 acquires the execution history (Dx, Dw, etc.) of the Li precipitation suppressing process of the battery pack 110 used in the vehicle 10 (steps S120 and S130). Rebuild information is generated using the acquired execution history of the Li precipitation suppression process. Then, a rebuilt product is generated according to the generated rebuild information. More specifically, when Dw is large, a rebuilt product is generated using a cell (cell A) having high lithium precipitation resistance (step S151), and when Dw is medium, lithium precipitation resistance is medium. A rebuilt product is generated using a cell (cell B) of about the same degree (step S152), and when Dw is small, a rebuilt product is generated using a cell (cell C) having low lithium precipitation resistance (step S153).

By generating the rebuilt product as described above, it is possible to provide the rebuilt product having excellent lithium precipitation resistance to the user who uses the battery pack 110 in which lithium precipitation is likely to occur on the negative electrode surface of the cell. Further, for a user who uses the battery pack 110 in which lithium precipitation is unlikely to occur on the negative electrode surface of the cell, it is possible to provide a rebuilt product excellent in terms other than lithium precipitation resistance. For example, the cell C selected in step S153 is a cell having a low internal resistance. Specifically, the internal resistance of the cell tends to increase as the amount of LiBOB added increases. By mounting the assembled battery manufactured by using the cell C having a low internal resistance on the vehicle 10, it is possible to improve the drivability (drivability, power performance, etc.) of the vehicle 10. As described above, in the battery management system 1, an appropriate replacement cell is selected in consideration of the difference in usage of the vehicle 10 for each user.

In the above embodiment, the usage of the user's vehicle 10 is classified into three categories (Dw: large, Dw: medium, Dw: small), and an appropriate replacement cell (any of cells A to C) suitable for the user. ) Is selected. The goodness of fit of the replacement cell is higher in the 3rd division than in the 2nd division. However, even if two categories are adopted, a certain effect can be achieved.

FIG. 11 is a diagram for explaining a conforming cell indicated by rebuild information (exchange information) generated in a modified example in which the user's usage of the vehicle is classified into two categories. FIG. 12 is a flowchart illustrating a processing procedure executed by the management server 20 in a modified example in which the user's usage of the vehicle is classified into two categories.

With reference to FIG. 12, in this modification, the process of FIG. 12 is executed instead of the process of FIG. The management server 20 executes steps S210 to S230 according to steps S110 to S130 of FIG. Next, in step S240, the management server 20 has suitable cells suitable for rebuilding (cell replacement) as cells A (LiBOB addition amount: large, Li precipitation resistance: high) and cell B (LiBOB) shown in FIG. It is determined whether the addition amount is small or the Li precipitation resistance is low). In steps S251 and S252, one of cells A and B is selected, and rebuild information for performing rebuild in the selected cell is generated. In steps S240, S251, and S252, the processes according to steps S142, S152, and S153 of FIG. 8 are performed, respectively. Next, the management server 20 executes steps S260 and S270 according to steps S160 and S170 of FIG.

As described above, even when the user's vehicle usage is classified into two categories (Dw: large, Dw: small), an appropriate replacement cell is selected in consideration of the difference in vehicle usage for each user. .. As a result, a rebuilt product having characteristics suitable for the user of the vehicle is generated.

FIG. 13 shows the results of evaluating the capacity retention rate before and after deterioration of the rebuilt product according to the example and the rebuilt product according to the comparative example.

The battery management system according to the embodiment was used to execute the above-described processing of FIG. 7 and the processing of FIG. In the process of FIG. 12, Th1 was set to 50%. On the other hand, the battery management system according to the comparative example is different from the battery management system according to the embodiment only in that cell B is selected in each of steps S251 and S252 of FIG.

Assembled batteries that were used in such a way that lithium precipitation was likely to occur on the negative electrode surface of the cell (more specifically, in such a way that Dw was higher than 50%) were generated in each of the systems of Examples and Comparative Examples. Rebuilt products were generated according to the rebuild information, and the capacity retention rate before and after deterioration was evaluated for each rebuilt product. In the evaluation, a predetermined durability test was performed on the rebuilt product, and the ratio of the capacity of the rebuilt product after the durability test (capacity retention rate) to the capacity of the rebuilt product before the durability test was measured.

With reference to FIG. 13, the capacity retention rate (74.1%) of the rebuilt product according to the example was higher than the capacity retention rate (68.2%) of the rebuilt product according to the comparative example. From this result, it is understood that the rebuilt product according to the example has a longer life than the rebuilt product according to the comparative example.

In the above embodiment, the amount of LiBOB added is adopted as the Li precipitation resistance index. However, the present invention is not limited to this, and any parameter indicating the degree of lithium precipitation resistance can be used as the Li precipitation resistance index. For example, when a lithium ion secondary battery in which lithium precipitation is likely to occur on the surface of the negative electrode (for example, a lithium ion secondary battery in which the negative electrode active material is a carbon-based material) is used as the cell, the amount of LiBOB added is replaced with the negative electrode. The amount of grain (hereinafter referred to as "negative electrode amount") or the BET specific surface area of the negative electrode (hereinafter referred to as "negative electrode BET") may be used. As the amount of negative electrode basis weight of the cell increases, the lithium precipitation resistance of the cell tends to increase. Further, the larger the negative electrode BET of the cell, the higher the lithium precipitation resistance of the cell tends to be. The basis weight is the amount of active material per unit area. The BET specific surface area is the specific surface area measured by the BET method.

A plurality of parameters may be adopted as the Li precipitation resistance index. For example, two or more of the LiBOB addition amount, the negative electrode basis weight amount, and the negative electrode BET may be adopted as the Li precipitation resistance index.

FIG. 14 is a diagram for explaining a compatible cell indicated by the amount of LiBOB added, the amount of negative electrode basis weight, and the rebuild information (exchange information) generated in the modified example in which the negative electrode BET is adopted as the Li precipitation resistance index. ..

With reference to FIG. 14, in this modification, the degree of lithium precipitation resistance (more specifically, resistance to lithium precipitation on the negative electrode surface of the cell) is determined based on the amount of LiBOB added, the amount of negative electrode grain, and the negative electrode BET. Calculate the overall evaluation score shown. The cells are classified into five cell categories (cell categories A to E) according to the calculated total evaluation points, and the rebuild information indicates which cell category the cell belongs to is a conforming cell.

The total evaluation score is calculated as follows, for example. In the evaluation of the amount of LiBOB added, the higher the amount of LiBOB added, the higher the score. For example, the magnitude of the LiBOB addition amount is divided into three, and points (evaluation points of the LiBOB addition amount) are given such as small (point 0), medium (point 1), and large (point 2). Further, in the evaluation of the negative electrode basis weight, a higher score is given as the negative electrode basis weight increases. For example, the size of the negative electrode basis weight is divided into two, and points (evaluation points of the negative electrode basis weight) are given such as small (point 0) and large (point 1). Further, in the evaluation of the negative electrode BET, the larger the negative electrode BET, the higher the score. For example, the size of the negative electrode BET is divided into two, and points (evaluation points of the negative electrode BET) are given, such as small (point 0) and large (point 1). The total of the evaluation points of the LiBOB addition amount, the negative electrode basis weight, and the negative electrode BET as described above is defined as the total evaluation point.

The cells having the overall evaluation points 4, 3, 2, 1, and 0 correspond to the cells belonging to the cell categories A, B, C, D, and E (that is, cells A, B, C, D, and E), respectively. Specifically, cell-1 having a total evaluation score of 4 corresponds to cell A. Cell-2 to cell-4 of the overall evaluation score 3 correspond to cell B. Cells-5 to 8 of the overall evaluation score 2 correspond to cell C. Cells -9 to -11 of the overall evaluation score 1 correspond to cell D. Cell-12 with a total evaluation score of 0 corresponds to cell E. It is judged that the higher the overall evaluation score, the higher the lithium precipitation resistance. When cells A to E are arranged in order from the one having the highest lithium precipitation resistance, cells A, cell B, cell C, cell D, and cell E are obtained.

In this modification, the usage of the user's vehicle is classified into 5 categories (Dw: maximum, Dw: large, Dw: medium, Dw: small, Dw: minimum), and the rebuild generated according to the usage of the user's vehicle. The information indicates which of cells A to E is the conforming cell. As a result, a rebuilt product having characteristics suitable for the user of the vehicle is generated.

In the above embodiment, the usage history information of the battery pack 110 (execution history of the Li precipitation suppression process, etc.) is periodically transmitted from the vehicle 10 to the management server 20. However, the present invention is not limited to this, and the usage history information of the battery pack 110 is accumulated in the vehicle 10, and when the vehicle 10 is brought to the store 35, the vehicle 10 is connected to the terminal 45 of the store 35, whereby the vehicle 10 is connected. The usage history information of the battery pack 110 stored in the terminal 45 may be transmitted from the terminal 45 to the management server 20.

In the above embodiment, the management server 20 calculates Dw. However, the present invention is not limited to this, and the Dw may be calculated in the vehicle 10 and the calculated Dw may be transmitted to the management server 20.

The exchange information (rebuild information in the above embodiment) may be generated not by the management server 20 but by any of the terminals 41 to 45 shown in FIG. 2, or a separately provided terminal. Further, the ECU 150 of the vehicle 10 may generate exchange information.

The execution history of the Li precipitation suppression process used for generating the exchange information (hereinafter referred to as “exchange information generation index”) is not limited to the Win limit frequency Dw in all running. For example, the ratio of the period during which the Li precipitation suppression control is executed in one year may be obtained based on the data for the latest one year instead of the total running, and this ratio may be used as the exchange information generation index. Further, the Dx of the most recent run may be used as an exchange information generation index. Further, a parameter that correlates with the peak frequency value in the execution frequency distribution of the Li precipitation suppression control (see FIGS. 5 and 6) may be used as an exchange information generation index.

An exchange information generation index considering the strength of the Li precipitation suppressing treatment (for example, the Win limit amount) may be used. For example, the exchange information generation index may be a parameter that correlates with the execution frequency of the Li precipitation suppression control in which the Win limit amount is larger than a predetermined value. Further, the exchange information generation index may be a parameter that correlates with the multiplication value (frequency × Win limit amount) of the frequency and the Win limit amount in the Win limit frequency distribution.

The Li precipitation suppressing treatment is not limited to the charging power limitation of the assembled battery, and may be arbitrary. For example, the temperature of the assembled battery may be controlled to suppress lithium precipitation on the electrode surface of the cell.

The configuration of the cells (lithium-ion secondary batteries) that make up the assembled battery mounted on the vehicle can be changed as appropriate. The lithium ion secondary battery constituting the assembled battery may be an all-solid-state battery. However, the battery information processing apparatus according to the present disclosure is suitable for manufacturing an assembled battery including a lithium ion secondary battery in which lithium precipitation is likely to occur on the electrode surface. For example, in a lithium ion secondary battery in which the negative electrode active material is an oxide-based material (LTO (lithium titanate) or the like), lithium precipitation is unlikely to occur on the negative electrode surface.

The embodiments disclosed this time should be considered to be exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the description of the embodiment described above, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1 Battery management system, 10,60-1-60-3 Vehicles, 20 Management servers, 31 Recovery companies, 32 Inspection companies, 33 Performance recovery companies, 34 Battery pack manufacturers, 35 Dealers, 36 Recyclers, 41-45 Terminal, 50 communication network, 51 base station, 62-1 to 62-3,110 Battery pack, 71 communication device, 72 control unit, 73 display unit, 112 battery monitoring unit, 120 PCU, 130 MG, 140 drive wheels, 150 ECU, 160 storage unit, 170, 220 communication device, 180 communication line, 210 information processing device, 230 recycled product DB, 240 battery information DB.

Claims (3)

A server that processes information for manufacturing an assembled battery including a plurality of cells.
The server is
An acquisition unit that acquires usage history information of the assembled battery used in the vehicle, and
A generator that generates exchange information for selecting a suitable cell for exchanging the cell from the exchange cell, and a generator .
It is provided with a database for accumulating replacement cell information regarding the replacement cell.
The cell is a lithium ion secondary battery and
In the vehicle, when a predetermined execution condition is satisfied, a Li precipitation suppression process for suppressing lithium precipitation on the electrode surface of the cell is executed.
The usage history information of the assembled battery includes the execution history of the Li precipitation suppressing process.
The replacement information indicates whether the cell belongs to the cell division of said replacement cells which are classified into a plurality of cells partitioned by a predetermined index indicating the degree of resistance to lithium deposition is said conforming cells,
The plurality of cell divisions include a first cell division and a second cell division having a lower resistance to lithium precipitation than the first cell division.
The generator
Using the execution history of the Li precipitation suppression process, the user's usage of the vehicle is determined.
When it is determined to be the first usage, the exchange information is generated by referring to the exchange cell information and preferentially selecting a cell belonging to the first cell category from the exchange cell as the conforming cell. death,
When it is determined that the second usage is less likely to cause lithium precipitation than the first usage, the replacement cell is referred to the replacement cell to select a cell belonging to the second cell category. Generate the exchange information to be preferentially selected as a conforming cell,
The server receives the use history information of the battery pack from the vehicle, configured to send the exchange information generated by the generating unit to the external terminal, server. The predetermined index is the amount of LiBOB added.
The server according to claim 1, wherein a cell having a larger amount of LiBOB added is classified into a cell category having a higher resistance to lithium precipitation. A battery management system comprising the server according to claim 1 or 2 and a terminal of a battery pack manufacturer.
The server transmits the exchange information generated by the generator to the terminal of the battery pack manufacturer, and the server transmits the exchange information to the terminal of the battery pack manufacturer.
The terminal of the battery pack manufacturer
An acquisition unit that acquires the exchange information from the server, and
A selection unit that selects the conforming cell from the replacement cells according to the exchange information acquired by the acquisition unit, and a selection unit.
A battery management system.

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