JP-7855142-B2 - Method for restoring electrodes and method for manufacturing electrodes for energy storage devices

Inventors

• 玉井 敦
• 石原 紗枝

Assignees

• 本田技研工業株式会社

Dates

Publication Date

20260507

Application Date

20240329

Priority Date

20230331

Claims (8)

1. A method for restoring the electrodes of a used energy storage device, A first step of evaluating the state of the electrode, A second step of compressing the electrode in the thickness direction of the electrode, Includes , The first step further includes a step of measuring the resistance component of the electrode, The aforementioned resistance component is the resistance of the composite layer or the interfacial resistance of the electrode. How to restore electrodes.
2. A method for restoring the electrodes of a used energy storage device, A first step of evaluating the state of the electrode, A second step of compressing the electrode in the thickness direction of the electrode, Includes, In the second step described above, the material is compressed while being heated . How to restore electrodes.
3. A method for restoring the electrodes of a used energy storage device, A first step of evaluating the state of the electrode, A second step of compressing the electrode in the thickness direction of the electrode, Includes, The second step further includes a calculation step of measuring the thickness of the electrode and calculating the difference from the estimated thickness before use. In the second step, the electrode is compressed in the thickness direction so that the thickness is reduced by the difference obtained in the calculation step . How to restore electrodes.
4. A method for restoring the electrodes of a used energy storage device, A first step of evaluating the state of the electrode, A second step of compressing the electrode in the thickness direction of the electrode, Includes, The second step further includes a coating step of applying a conductive agent to the surface of the electrode . How to restore electrodes.
5. The electrode recovery method according to claim 4 , wherein the conductive agent is carbon fiber.
6. The method for restoring an electrode according to claim 4 , wherein the coating step is a step of applying a dispersion in which the conductive agent is dispersed and drying it.
7. The electrode recovery method according to claim 6 , wherein ultrasonic waves are applied to the electrode in the coating step.
8. The process of preparing electrodes for used energy storage devices, A step of restoring the electrode using the method according to any one of claims 1 to 7, A method for manufacturing electrodes for energy storage devices, comprising the same components.

Description

The present invention relates to a method for restoring electrodes , electrodes for energy storage devices , and a method for manufacturing the same . This application claims priority based on Japanese Patent Application No. 2023-057930, filed in Japan on March 31, 2023, and the contents of that application are incorporated herein by reference. In recent years, research and development has been conducted on the reuse of secondary batteries to contribute to energy efficiency, in order to ensure that more people have access to affordable, reliable, sustainable, and advanced energy (see, for example, Patent Document 1). Japanese Patent Application Publication No. 2012-022969 This is a flowchart of the electrode recovery method according to the first embodiment of the present invention.This is a schematic diagram showing the configuration of the electrodes.This figure illustrates an example of the dV/dQ curves for the initial state of the positive and negative electrodes.This figure illustrates an example of a measured dV/dQ curve for an energy storage device and a fitted curve.This figure illustrates a comparison between the dV/dQ curve in the initial state and the diagnostic dV/dQ curve.This is a flowchart of the electrode recovery method according to the second embodiment of the present invention. The following describes an electrode recovery method according to one embodiment of the present invention, with reference to the drawings. Figure 1 is a flowchart of the electrode recovery method according to one embodiment of the present invention. The electrode recovery method of this disclosure is a method for recovering an electrode of a used energy storage device, and includes a first step S1 of evaluating the condition of the electrode and a second step S2 of compressing the electrode in the thickness direction of the electrode. Each step will be described below. (First step S1) In the first step S1, the state of the electrodes of the used energy storage device is evaluated. In the first step S1, the state of the electrodes of the used energy storage device may be evaluated based on physical quantity data obtained during the charging and discharging of the used energy storage device. Physical quantity data includes, for example, the voltage value and current value during charging. (Used energy storage devices) A used energy storage device has electrodes comprising an active material, a binder, and a current collector. The energy storage device is not particularly limited as long as it can store electricity and has electrodes comprising an active material, a binder, and a current collector. An example of an energy storage device is a lithium-ion secondary battery. Figure 2 is a schematic diagram showing the configuration of the electrodes. The electrodes targeted by the active material separation method of this disclosure are a positive electrode 10 and a negative electrode 20. The configuration of the electrodes will be described below. "Positive electrode" The positive electrode 10, which is an electrode, includes a positive electrode active material 11, a positive electrode conductive additive 12, a positive electrode binder 13, and a positive electrode current collector 14. The layer consisting of the positive electrode active material 11, the positive electrode conductive additive 12, and the positive electrode binder 13 is called the positive electrode composite layer. The positive electrode composite layer may be formed on one or both sides of the positive electrode current collector 14. Note that if the positive electrode active material 11 is conductive, the positive electrode composite layer does not need to contain the positive electrode conductive additive 12. The positive electrode active material 11, which is the active material used in the positive electrode, is not particularly limited as long as it is capable of intercalating and releasing Li ions. Examples of positive electrode active material 11 include lithium nickel oxide (e.g., LiNiO₂ ), lithium cobalt oxide (e.g., LiCoO₂ ), lithium nickel cobalt oxide, lithium nickel cobalt manganese oxide, LiFePO₄ , LiMn 1 -x Fe x PO₄ , LiMnPO₄, LiCoPO₄ , LiNiPO₄, etc. Preferably, the positive electrode active material 11 contains one or more selected from the group consisting of manganese, nickel, and cobalt. The positive electrode conductive additive 12, used in the positive electrode 10, assists in the formation of a conductive path between the positive electrode active material 11 and the positive electrode current collector 14. The positive electrode conductive additive 12 is not particularly limited as long as it is conductive; examples include carbon black such as acetylene black, carbon nanotubes, and graphite such as artificial graphite. The positive electrode binder 13, which is a binder for the positive electrode active material 11, binds the positive electrode active material 11, the positive electrode conductive additive 12, and the positiv