JP7754147B2 - Electrode body manufacturing apparatus and electrode body manufacturing method - Google Patents

Description

This disclosure relates to an electrode assembly manufacturing apparatus and an electrode assembly manufacturing method.

The electrode sheet drying device disclosed in Patent Document 1 is configured so that a rolled electrode sheet is unwound, an infrared irradiation unit irradiates infrared rays from outside the chamber to heat and dry the electrode sheet, and then the electrode sheet can be wound up inside the chamber. Either the output of the infrared irradiation unit or the feed speed of the electrode sheet, or both, are adjusted so that the temperature of the electrode sheet reaches a predetermined set temperature.

JP 2014-107237 A

The inventors of the present application have discovered the following problems.
When such an electrode sheet drying device is used to heat an electrode sheet having a coated area where an electrode material is coated and a non-coated area where no electrode material is coated, the coated area and the non-coated area are heated in the same manner, which may cause cracks.

This disclosure was made in consideration of the above-mentioned problems, and aims to provide an electrode assembly manufacturing device and electrode assembly manufacturing method that can suppress the occurrence of cracks.

The electrode assembly manufacturing apparatus according to the present disclosure comprises:
a foil conveyor that continuously conveys the electrode foil;
a coater that intermittently coats a main surface of the electrode foil that is continuously conveyed with an electrode material to intermittently form coated regions where the electrode material is coated and uncoated regions where the electrode material is not coated;
an acquisition unit that acquires the position of the uncoated region;
a laser irradiator that irradiates the electrode foil with laser light;
an output control unit;
the output control unit controls an output of the laser irradiator so that, during a period in which the uncoated region is included in the irradiation range of the laser light, the laser irradiator irradiates the coated region with the laser light at a first output intensity and irradiates the uncoated region with the laser light at a second output intensity;
The second output intensity is lower compared to the first output intensity.

Furthermore, in the above-mentioned electrode assembly manufacturing apparatus, the second output intensity may be 0 (zero).

The method for manufacturing an electrode assembly according to the present disclosure includes:
continuously conveying the electrode foil;
intermittently applying an electrode material to a main surface of the continuously transported electrode foil, thereby intermittently forming a coated region where the electrode material is applied and an uncoated region where the electrode material is not applied;
obtaining the location of the uncoated area;
irradiating the electrode foil with laser light from a laser irradiator;
The method includes a step of irradiating the laser light to the uncoated area at a first output intensity while irradiating the laser light to the uncoated area at a second output intensity during a period in which the uncoated area is included in the irradiation range of the laser light.

Furthermore, in the above-described method for manufacturing an electrode body, in the step of irradiating the uncoated area with the laser light at the second output intensity, irradiation of the laser light onto the uncoated area may be stopped.

This disclosure makes it possible to suppress the occurrence of cracks.

1 is a schematic diagram showing an electrode body manufacturing apparatus according to a first embodiment. 3 is a flowchart showing a method for manufacturing an electrode assembly according to the first embodiment. 3A to 3C are schematic diagrams showing a method for manufacturing an electrode body according to the first embodiment. FIG. 1 is a schematic diagram showing an experiment.

Specific embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention is not limited to the following embodiments. Furthermore, the following description and drawings have been simplified as appropriate for clarity.

First Embodiment
A first embodiment will be described with reference to FIGS. 1 to 3. FIG.

It should be understood that the right-handed XYZ coordinate system shown in Figure 1 and other drawings is a matter of convenience for explaining the positional relationships of the components. Normally, the positive Z axis is vertically upward, and the XY plane is the horizontal plane, which is common to all drawings. The positive X axis is the feed direction of the electrode foil FF, which will be described later. The Y axis direction is the width direction of the electrode foil FF.

<Manufacturing equipment>
As shown in FIG. 1 , an electrode body manufacturing apparatus 10 includes a laser irradiator 1 , a foil conveyor 2 , a coater 3 , a sensor 4 , a control device 5 , and an output control unit 6 .

The electrode foil roll FR is formed into a roll by winding the electrode foil FF around it. The electrode foil roll FR is rotatably positioned at a predetermined position. By rotating, the electrode foil roll FR can feed the electrode foil FF in the feed direction (here, the positive direction of the X-axis). A take-up roll (not shown) may be positioned in the feed direction. This take-up roll (not shown) winds up the electrode foil FF fed by the electrode foil roll FR. The electrode foil FF is made of, for example, stainless steel, aluminum, copper, nickel, iron, titanium, or carbon.

The foil conveyor 2 continuously conveys the electrode foil FF in the feed direction. The foil conveyor 2 may convey the electrode foil FF using a roll-to-roll method. The foil conveyor 2 may, for example, include multiple rolls 2A. The multiple rolls 2A may be arranged between the electrode foil roll FR and the take-up roll side FW on which the above-mentioned take-up roll is located. Furthermore, the multiple rolls 2A may be arranged at predetermined intervals below the electrode foil FF. A drive source (not shown) applies a rotational drive force to the multiple rolls 2A, causing them to rotate. This allows the electrode foil FF to be conveyed in the feed direction.

The applicator 3 intermittently applies electrode material FA to the main surface FS of the electrode foil FF, which is continuously conveyed by the foil conveyor 2. This intermittently forms coated regions FC and uncoated regions FU on the main surface FS of the electrode foil FF. The lengths of the coated regions FC in the feed direction and the uncoated regions FU in the feed direction are preferably set in advance. On the main surface FS, the coated regions FC and uncoated regions FU are arranged alternately in the feed direction. The coated regions FC are coated with electrode material FA. In the coated regions FC, the electrode material FA covers the main surface FS of the electrode foil FF. In the uncoated regions FU, the electrode material FA is not applied. In the uncoated regions FU, the electrode material FA does not cover the main surface FS of the electrode foil FF, leaving the main surface FS of the electrode foil FF exposed.

The electrode material FA includes an electrode active material. The electrode active material is a positive electrode active material or a negative electrode active material.

The electrode material FA containing a positive electrode active material constitutes a positive electrode. Examples of the positive electrode active material include lithium cobalt oxide (LiCoO ₂ ), lithium nickel oxide (LiNiO ₂ ), lithium manganese oxide (LiMn ₂ O ₄ ), LiCo _1/3 Ni _1/3 Mn _1/3 O ₂ , and a heteroelement-substituted Li—Mn spinel having a composition represented by Li _1+x Mn _2-x-y M _y O ₄ (M is one or more metal elements selected from Al, Mg, Co, Fe, Ni, and Zn).

An electrode material FA containing a negative electrode active material constitutes a negative electrode. The negative electrode active material is, for example, a material capable of absorbing and releasing metal ions such as metallic lithium or lithium ions. Materials capable of absorbing and releasing metal ions such as lithium ions include, for example, alloy-based negative electrode active materials or carbon materials. Examples of alloy-based negative electrode active materials include Si alloy-based negative electrode active materials or Sn alloy-based negative electrode active materials. Examples of Si alloy-based negative electrode active materials include silicon, silicon oxide, silicon carbide, silicon nitride, or solid solutions thereof. Si alloy-based negative electrode active materials may also include elements other than silicon, such as Fe, Co, Sb, Bi, Pb, Ni, Cu, Zn, Ge, In, Sn, and Ti. Examples of Sn alloy-based negative electrode active materials include tin, tin oxide, tin nitride, or solid solutions thereof. The Sn alloy-based negative electrode active material may also contain elements other than tin, such as Fe, Co, Sb, Bi, Pb, Ni, Cu, Zn, Ge, In, Ti, and Si. The carbon material may be, for example, hard carbon, soft carbon, or graphite.

The electrode material FA may optionally contain conductive additives, binders, and solid electrolytes. Examples of conductive additives include carbon materials such as vapor-grown carbon fiber (VGCF) and carbon nanofibers, or metal materials. Examples of binders include polyvinylidene fluoride (PVdF), carboxymethyl cellulose (CMC), butadiene rubber (BR), styrene butadiene rubber (SBR), or combinations thereof.

Sensor 4 detects the uncoated area FU. Specifically, sensor 4 detects the position, size, etc. of the uncoated area FU. Sensor 4 is preferably provided at a distance from the coater 3 in the feed direction. Sensor 4 is preferably located, for example, above the main surface FS of the electrode foil FF. For example, a line scan camera may be used as sensor 4.

The laser irradiator 1 irradiates a predetermined irradiation area with laser light LL. Specifically, the output intensity of the laser light LL from the laser irradiator 1 can be changed depending on the location of the irradiation area. More specifically, if the irradiation area includes a first region and a second region, the output intensity of the laser light LL irradiated to the first region differs from the output intensity of the laser light LL irradiated to the second region. The laser irradiator 1 is, for example, a surface-emitting laser. Such a surface-emitting laser is, for example, a vertical cavity surface-emitting laser (VCSEL). The laser irradiator 1 is positioned above the main surface FS of the electrode foil FF. The laser irradiator 1 irradiates the electrode foil FF with laser light LL. Note that while the example of the electrode assembly manufacturing apparatus 10 shown in FIG. 1 includes two laser irradiators 1, the electrode assembly manufacturing apparatus 10 may include one or three or more laser irradiators 1.

The control device 5 can be configured with a processor such as a CPU (Central Processing Unit). In other words, the control device 5 can have the functions of a computer. The control device 5 can execute programs stored in a storage device (not shown) and perform various processes.

Furthermore, by executing this program, the control device 5 appropriately realizes the functions of the components required for the electrode body manufacturing apparatus 10 to perform the necessary operations. For example, the control device 5 acquires various information from each component of the electrode body manufacturing apparatus 10, such as the applicator 3 and the sensor 4. The control device 5 may store this acquired information in a storage device. Examples of the information include the completion of application of electrode material FA to the main surface FS of the electrode foil FF by the applicator 3 and the uncoated area FU detected by the sensor 4. The control device 5 may store information in the storage device, such as the transport speed of the electrode foil FF by the foil transport device 2, the distance between the applicator 3 and the irradiation range of the laser light LL, and the irradiation range of the laser light LL. Based on this stored information, the control device 5 can calculate the position of the uncoated area FU. The control device 5 functions as an acquisition unit that acquires the position of the uncoated area FU. Furthermore, the control device 5 determines whether the uncoated area FU is included in the irradiation range of the laser light based on the acquired position of the uncoated area FU. The control device 5 sends a signal to the output control unit 6 to control the output of the laser irradiator 1 depending on whether or not the uncoated area FU is within the irradiation range of the laser light.

The output control unit 6 controls the output of the laser irradiator 1 in response to a signal from the control device 5. Specifically, during a period when the uncoated area FU is included in the irradiation range of the laser light LL, the output control unit 6 controls the output of the laser irradiator 1 so that the laser light LL is irradiated to the coated area FC at a first output intensity while the laser light LL is irradiated to the uncoated area FU at a second output intensity. The second output intensity is lower than the first output intensity. During a period when the uncoated area FU is not included in the irradiation range of the laser light LL, the output control unit 6 controls the output of the laser irradiator 1 so that the laser light LL is irradiated to the coated area FC at the first output intensity. In other words, the period when the uncoated area FU is not included in the irradiation range of the laser light LL is a period when the irradiation range of the laser light LL includes only the coated area FC but does not include the uncoated area FU at all. The second output intensity may be 0 (zero). In other words, during the period when the uncoated area FU is included in the irradiation range of the laser light LL, the output control unit 6 may stop irradiating the uncoated area FU with the laser light LL while irradiating the coated area FC with the laser light LL at the first output intensity.

<Manufacturing method>
Next, a method for manufacturing an electrode body using the above-described electrode body manufacturing apparatus 10 will be described with reference to Figures 1 to 3. For ease of understanding, the illustration of each component such as the foil conveyor 2, coater 3, sensor 4, control device 5, and output control unit 6 has been omitted as appropriate in Figure 3.

The foil conveyor 2 continuously conveys the electrode foil FF (step ST1). The applicator 3 intermittently applies electrode material FA to the main surface FS of the continuously conveyed electrode foil FF (step ST2). As a result, coated areas FC, where the electrode material FA is applied, and uncoated areas FU, where the electrode material FA is not applied, are intermittently formed on the main surface FS of the electrode foil FF. Note that steps ST1 and ST2 may start approximately simultaneously, or may be performed simultaneously in parallel with the next step ST3.

Next, the control device 5 acquires the position of the uncoated area FU1 (step ST3). Specifically, the control device 5 calculates the position of the uncoated area FU1 based on the uncoated area FU1 detected by the sensor 4, the conveying speed of the electrode foil FF by the foil conveyor 2, etc.

Next, the control device 5 determines whether the irradiation range of the laser light LL includes the uncoated area FU1 (step ST4). The control device 5 makes this determination based on the position of the uncoated area FU1, the irradiation range of the laser light LL, etc.

If the control device 5 determines that the irradiation range of the laser light LL does not include the uncoated area FU (step ST4: NO), the laser irradiator 1, under control of the output control unit 6, irradiates the coated area FC1 with the laser light LL at the first output intensity (step ST52). The electrode material FA in the coated area FC1 is supplied with the necessary amount of heat and is sufficiently heated.

On the other hand, if the control device 5 determines that the irradiation range of the laser light LL includes the uncoated area FU (step ST4: YES), the laser irradiator 1, under control of the output control unit 6, irradiates the coated areas FC1 and FC2 with the laser light LL at a first output intensity while irradiating the uncoated area FU with the laser light L1 at a second output intensity (step ST51). As described above, the second output intensity is lower than the first output intensity. The second output intensity may be 0 (zero). In other words, the laser light LL may be irradiated to the coated areas FC1 and FC2 at the first output intensity while irradiating the uncoated area FU with the laser light L1. Therefore, the amount of heat supplied to the electrode material FA in the uncoated area FU1 is lower than the amount of heat supplied to the electrode material FA in the coated areas FC1 and FC2. Therefore, the temperature of the uncoated area FU1 is less likely to rise than the temperatures of the coated areas FC1 and FC2.

The above-described steps ST4, ST51, and ST52 are repeated until the laser light irradiation is complete (step ST6: NO). After the uncoated area FU1 passes through the irradiation range of the laser light LL, the uncoated area FU1 portion of the electrode foil FF may be wound up on a winding roll (not shown). Various processes may be performed on the electrode foil FF as needed.

The electrode body can be manufactured in this way.

According to the configuration of the electrode assembly manufacturing method described above, during the period when the uncoated area FU is included in the irradiation range of the laser light LL, the laser irradiator 1 irradiates the coated area FC with the laser light LL at a first output intensity while irradiating the uncoated area FU with the laser light L1 at a second output intensity. Furthermore, the second output intensity is lower than the first output intensity. The temperature of the uncoated area FU1 is less likely to rise than the temperatures of the coated areas FC1 and FC2. Therefore, irradiation of the laser light to the uncoated area FU1 can be suppressed while ensuring a sufficient amount of irradiation of the laser light LL to the coated areas FC1 and FC2. This suppresses heat transfer from the uncoated area FU1 to the ends of the coated areas FC1 and FC2 adjacent to the uncoated area FU1, thereby suppressing drying of the ends of the coated areas FC1 and FC2. As a result, the electrode material FA is less likely to crack at the ends of the coated areas FC1 and FC2. Therefore, the amount of laser light irradiation can be changed depending on the coated areas FC1, FC2 and the uncoated area FU1, thereby preventing cracks from occurring. Furthermore, there is no need to extend the drying process or drying time throughout the entire process to prevent cracks from occurring. This allows for a reduction in the length of the drying process line and the number of laser irradiators 1.

Furthermore, when the second output intensity is 0 (zero), irradiation of the uncoated area FU with laser light can be further suppressed. Therefore, the occurrence of cracks can be further suppressed.

<Experiment>
Next, an experiment using a specific example of the electrode assembly manufacturing apparatus 10 will be described with reference to FIG.

One specific example of an electrode body manufacturing apparatus 10 includes a laser irradiator 1A shown in Figure 4. The laser irradiator 1A is a specific example of a laser irradiator 1 and is a vertical cavity surface emitting laser. The laser irradiator 1 is equipped with a laser head 1a, and irradiates the main surface of the workpiece WW with a laser from the laser head 1a. The laser irradiator 1A irradiates the first area LA1 with laser light at a first output intensity and the second area LA2 with laser light at a second output intensity. The laser irradiator 1A also stops irradiating the third area LA3. In other words, the example of the laser irradiator 1 shown in Figure 4 irradiates the third area LA3 with laser light at an output intensity of 0 (zero). Here, the electrode foil FF is transported so that the coated area FC1 in the electrode assembly manufacturing method shown in Figure 3 is aligned with the first area LA1, the coated area FC2 with the second area LA2, and the uncoated area FU1 with the third area LA3, and the laser irradiator 1A is irradiated as described above. Then, the coated areas FC1 and FC2 are heated, while heating of the uncoated area FU1 is stopped. Therefore, by using the laser irradiator 1A shown in Figure 4, the amount of laser light irradiation can be changed depending on the coated areas FC1, FC2, and uncoated area FU1, thereby suppressing the occurrence of cracks.

The present invention is not limited to the above-described embodiment, and modifications can be made as appropriate without departing from the spirit of the invention. Furthermore, the present invention may be implemented by combining the above-described embodiment and examples thereof as appropriate.

10 Electrode body manufacturing apparatus 1, 1A Laser irradiator 1a Laser head 2 Foil conveyor 2A Roll 3 Coater 4 Sensor 5 Control device 6 Output control unit LL, L1 Laser light LA1 First area LA2 Second area LA3 Third area FF Electrode foil FS, FS1 Main surface FA, FA1, FA2 Electrode material FR Electrode foil roll FW Winding roll side FC, FC1, FC2 Coated area FU, FU1 Uncoated area WW Work

Claims (4)

a foil conveyor that continuously conveys the electrode foil;
a coater that intermittently coats a main surface of the electrode foil that is continuously conveyed with an electrode material to intermittently form coated regions where the electrode material is coated and uncoated regions where the electrode material is not coated;
an acquisition unit that acquires the position of the uncoated region;
a laser irradiator that irradiates the electrode foil with laser light;
an output control unit;
the output control unit controls an output of the laser irradiator so that, during a period in which the uncoated region is included in the irradiation range of the laser light, the laser irradiator irradiates the coated region with the laser light at a first output intensity and irradiates the uncoated region with the laser light at a second output intensity;
the second output intensity is low compared to the first output intensity;
Electrode body manufacturing equipment. the second output intensity is 0 (zero);
The electrode assembly manufacturing apparatus according to claim 1 . continuously conveying the electrode foil;
intermittently applying an electrode material to a main surface of the continuously transported electrode foil, thereby intermittently forming a coated region where the electrode material is applied and an uncoated region where the electrode material is not applied;
obtaining the location of the uncoated area;
irradiating the electrode foil with laser light from a laser irradiator;
and irradiating the uncoated area with the laser light at a second output intensity while irradiating the coated area with the laser light at a first output intensity during a period in which the uncoated area is included in the irradiation range of the laser light.
A method for manufacturing an electrode body. In the step of irradiating the uncoated region with the laser light at the second output intensity, irradiating the uncoated region with the laser light is stopped.
The method for manufacturing the electrode assembly according to claim 3 .