Stripping device for stripping positive electrode current collector from positive electrode composite material

Abstract

The invention provides a stripping device for stripping a positive electrode current collector from a positive electrode composite material, and aims to effectively separate the positive electrode current collector from the positive electrode composite material. A peeling device for peeling a positive electrode current collector from a positive electrode composite material is provided with: an energization region provided with an electrode; a shock wave transmission region that accommodates the positive electrode plate; the separating plate is used for separating the areas; and a power supply device for supplying power to the electrode, in the stripping device, discharge is performed between the electrode and the separator, a shock wave generated in the energization region is transmitted to the positive electrode plate in the shock wave transmission region through the separator, and the positive electrode composite material is stripped from the positive electrode current collector of the positive electrode plate.

Description

Technical Field

[0001] The present invention relates to a stripping device for stripping a positive electrode current collector from a positive electrode composite material. Background Art

[0002] In lithium-ion batteries and all-solid-state batteries, some batteries have stacked electrodes consisting of a positive plate and a negative plate stacked with a separator. The positive plate of such a battery is composed of a positive electrode collector and a positive electrode composite material. The positive electrode composite material uses a ternary positive electrode material (NCM) including nickel, cobalt, and manganese. When the battery is discarded, it is desirable to recycle valuable metals such as NCM. The positive electrode composite material is bonded to the aluminum foil serving as the positive electrode collector by the binder possessed by the positive electrode composite material.

[0003] Conventionally, there is known a technique for placing cut pieces of a positive electrode plate composed of aluminum foil and a positive electrode composite material in water and generating shock waves in the water by electric pulse discharge to separate different materials (for example, see Patent Document 1).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2023-086495 Summary of the Invention

[0007] Problems to be solved by the invention

[0008] However, as in Patent Document 1, when a cut piece of a positive electrode plate is placed in water and an electric pulse is discharged in the water to generate a shock wave, the positive electrode plate contains an electrolyte, which increases the electrical conductivity of the water and reduces the dielectric breakdown strength, thereby weakening the power of the shock wave.

[0009] In addition, a portion of the container in which the positive electrode plate is placed may be shattered by the shock wave of the electric pulse discharge, and the metal of the container may be mixed in.

[0010] The present invention has been made in view of the above circumstances, and an object of the present invention is to effectively separate a positive electrode current collector from a positive electrode composite material.

[0011] Means for solving problems

[0012] The stripping device for stripping the positive electrode collector and the positive electrode composite material in the present invention comprises: a power-on area, which has an electrode; a shock wave transmission area, which accommodates the positive electrode plate; an isolation plate, which separates the areas; and a power supply device, which provides power to the electrode, transmits the shock wave generated in the power-on area to the positive electrode plate in the shock wave transmission area via the isolation plate, and strips the positive electrode composite material from the positive electrode collector of the positive electrode plate.

[0013] Effects of the Invention

[0014] The present invention provides a stripping device capable of effectively separating a positive electrode current collector and a positive electrode composite material. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a diagram schematically showing a target battery to which the battery processing method of the present invention can be applied.

[0016] Figure 2 This is a schematic diagram of a stripping device for stripping the positive electrode current collector and the positive electrode composite material.

[0017] Description of labels

[0018] 10: target battery; 11: positive electrode plate; 12: negative electrode plate; 13: separator; 21: laminated electrode; 22: laminated member; 23A, 23B: collector ears; 31: positive electrode collector; 32: positive electrode composite material; 41: negative electrode collector; 42: negative electrode composite material; 101: stripping device; 102: power supply device; 103: device body; 105: output terminal; 107: ground terminal; 111: energized area; 113: shock wave transmission area; 115: electrode support; 117: electrode; 119: separator; 121: energized space; 123: stripping space; E: electrical ground; X: first liquid; Y: second liquid. DETAILED DESCRIPTION

[0019] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. (Embodiment)

[0020] [1. Structure of the target battery]

[0021] Figure 1 This figure shows the structure of a target battery 10, an example of a battery to which the present disclosure is applicable, and schematically illustrates a cross-section of the target battery 10. The target battery 10 is a secondary battery capable of both charge and discharge. The target battery 10 described in this embodiment is a laminated battery having battery materials enclosed within a laminate member 22, and has an overall flat plate shape. The target battery 10 can be categorized as a pouch-type battery, a laminate-type battery cell, a pouch-type battery cell, a lithium-ion battery cell, or a battery module.

[0022] The target battery 10 is a secondary battery known as a lithium-ion battery, which has attracted attention as a storage device with high energy density. Examples of positive electrode active materials for lithium-ion batteries include lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, and lithium iron phosphate. In addition, examples of positive electrode active materials include ternary positive electrode materials (NCMs) containing nickel, cobalt, and manganese. Examples of negative electrode active materials for lithium-ion batteries include carbon-based materials. In addition, all-solid-state batteries using solid electrolytes as electrolytes for lithium-ion batteries are known.

[0023] Nickel, cobalt, and manganese, which are used as positive electrode active materials in lithium-ion batteries, all-solid-state batteries, and the like, are known as valuable metals and are therefore required to be recovered from used batteries.

[0024] like Figure 1 As shown, the target battery 10 has a structure in which a laminated electrode 21 is housed in a laminate member 22. The laminate member 22 is a laminate film having a base material made of a metal material such as aluminum alloy or stainless steel. The laminate member 22 functions as a sealant that seals the outer casing of the target battery 10 and the laminated electrode 21.

[0025] The target battery 10 of this embodiment has a flat plate shape formed by laminating two laminate members 22 . A pair of collector tabs 23A and 23B for extracting power from the target battery 10 penetrates the outer casing and is exposed from the end of the target battery 10 .

[0026] The laminated electrode 21 is a multilayer structure composed of a stack of positive plates 11 and negative plates 12, with separators 13 disposed between each of the positive and negative plates 11, 12. The separators 13 are disposed between the positive and negative plates 11, 12 to prevent short circuits between the positive and negative plates 11, 12.

[0027] The positive electrode plates 11 and the negative electrode plates 12 are alternately arranged, and one positive electrode plate 11 and one negative electrode plate 12 facing each other constitute one electrode plate pair. A stacked electrode 21 is formed by stacking a plurality of electrode plate pairs.

[0028] The positive electrode plate 11 includes a rectangular plate-shaped positive electrode current collector 31, with a positive electrode composite material 32 disposed on both sides of the positive electrode current collector 31. The positive electrode current collector 31 is an aluminum alloy or pure aluminum material formed into a foil or plate shape. The positive electrode composite material 32 includes, for example, a positive electrode active material, a conductive material, a conductive additive, and a binder. The positive electrode plate 11 has a positive terminal 11A extending from an end of the positive electrode plate 11. The positive terminals 11A extending from the multiple positive electrode plates 11 constituting the stacked electrode 21 are each connected to a collector lug 23A.

[0029] The negative electrode plate 12 includes a rectangular negative electrode current collector 41. A negative electrode composite material 42 is provided on the surface of the negative electrode current collector 41 that faces the positive electrode plate 11. Copper foil, for example, is used for the negative electrode current collector 41. The negative electrode plate 12 has a negative electrode terminal 12A extending from an end of the negative electrode plate 12. Each of the negative electrode terminals 12A extending from the multiple negative electrode plates 12 that constitute the stacked electrode 21 is connected to a collector tab 23B.

[0030] The collector tabs 23A and 23B are formed of a thin plate-shaped metal material such as copper or aluminum, and are passed between the two laminated members 22 to be exposed to the outside.

[0031] When the target battery 10 is a lithium-ion battery, the interior of the laminated member 22 is filled with a liquid or gel electrolyte. The electrolyte includes, for example, an electrolyte, a solvent, and an additive. Examples of the electrolyte include lithium salts such as lithium hexafluorophosphate (LiPF6). Examples of the solvent and additive include carbonates such as ethylene carbonate, dimethyl carbonate, diethyl carbonate, and ethylene carbonate. These are merely examples, and the electrolyte, solvent, and additive can be appropriately selected and modified.

[0032] When the target battery 10 is an all-solid-state battery, a solid electrolyte is disposed within the laminated member 22. Oxide-based electrolytes and sulfide-based electrolytes are known as solid electrolytes, but even all-solid-state batteries using other materials can be applied to the present disclosure. For example, the solid electrolyte of an all-solid-state battery is disposed between the positive electrode plate 11 and the negative electrode plate 12 in place of the separator 13. In this case, the solid electrolyte not only functions as an electrolyte but also prevents short circuits between the positive electrode plate 11 and the negative electrode plate 12.

[0033] [2. Peeling device]

[0034] Figure 2 It is a schematic diagram of a peeling device 101 for peeling the positive electrode current collector 31 and the positive electrode composite material 32 .

[0035] The peeling device 101 includes a power supply device 102 that generates electricity. The power supply device 102 outputs instantaneous high-voltage, high-power electricity within a short period of time, such as microseconds or nanoseconds. The main body of the power supply device 102 is covered by a Faraday cage 8 that provides electromagnetic shielding. The power supply device 102 includes, for example, a capacitor that accumulates a predetermined charge and discharges it instantaneously. The power supply device 102 has an output terminal 105 that outputs a pulse voltage. The power supply device 102 is connected to an electrical ground E that electrically connects the power supply device 102 to the earth. The power supply device 102 also includes a ground terminal 107 connected to the electrical ground E.

[0036] The peeling device 101 includes a device body 103. The device body 103 is a hollow container made of metal such as stainless steel. Figure 2In the figure, the device body 103 is shown in a partial cross-sectional view. The hollow interior of the device body 103 is partitioned by a separator 119. Separator 119 is a grounded flat plate made of a metal such as stainless steel. In this embodiment, the upper portion of separator 119 forms a current-carrying region 111 where shock waves are generated, while the lower portion of separator 119 forms a shock wave transmission region 113 where shock waves are transmitted to the positive electrode plate 11.

[0037] The current-carrying region 111 includes an electrode support 115 at its upper portion and an electrode 117 supported by the lower end of the electrode support 115. Electrode 117 is electrically connected to the output terminal 105 of the power supply device 102. The current-carrying space 121 of the current-carrying region 111 is filled with an organic liquid (first liquid X) such as water or oil. A separator 119 is electrically connected to the ground terminal 107 of the power supply device 102.

[0038] The separation space 123 in the shock wave transmission area 113 is filled with a liquid such as water (second liquid Y). A positive electrode plate 11 is disposed in the separation space 123. The positive electrode plate 11 is composed of a positive electrode current collector 31 and a positive electrode composite material 32. Multiple positive electrode plates 11 are stacked in the separation space 123.

[0039] In the peeling device 101 , a shock wave is generated when the electric field intensity generated by the power supply device 102 exceeds the dielectric breakdown limit of the first liquid X filling the energized area 111 .

[0040] The shock wave generated in the energized region 111 propagates to the second liquid Y in the shock wave transmission region 113 via the isolation plate 119 .

[0041] [3. Actions and Effects]

[0042] Next, the operation and effect of peeling the positive electrode composite material 32 from the positive electrode current collector 31 of the positive electrode plate 11 will be described. The positive electrode plate 11 is separated from the target battery 10 by a known technique and placed in the shock wave transmission region 113 .

[0043] When a discharge occurs between the electrode 117 and the separator 119, the first liquid X in the discharge path instantly forms bubbles, generating a shock wave. This shock wave propagates through the first liquid X to the separator 119, then through the separator 119 to the second liquid Y, and finally through the second liquid Y to the positive electrode plate 11. Repeated power flow from the power supply 102 causes repeated discharge within the discharge path, generating shock waves that peel the positive electrode composite material 32 from the positive electrode collector 31 of the positive electrode plate 11. After a predetermined number of repetitions of power flow and peeling, the shock wave transmission area 113 is removed, and the water, peeled positive electrode collector 31, and positive electrode composite material 32 are screened and recovered.

[0044] When the shock wave transmission region 113 is refilled with water, the positive electrode plate 11 is placed thereon, and the power supply device 102 is repeatedly energized, the positive electrode composite material 32 can be continuously peeled from the positive electrode current collector 31 .

[0045] Furthermore, to prevent the shock wave's energy from being attenuated, the first liquid X is preferably a liquid that easily conducts the shock wave. This corresponds to, for example, a liquid with a density greater than that of water. Furthermore, to amplify the shock wave's energy, the first liquid X is preferably a liquid with high dielectric strength. Furthermore, since the metal forming the separator 119 dissolves, the dielectric strength of the first liquid X decreases. Therefore, the lower the solubility of the metal compared to water, the better. Since the metal on the surface of the separator 119 may be shattered by the impact force of the current, the metal is particularly susceptible to dissolution within the current-carrying area 111. For these reasons, the first liquid X is particularly preferably an organic liquid.

[0046] In addition, assuming that in the stripping device 101, the energized area 111 and the shock wave transmission area 113 are formed as a whole, the dielectric breakdown strength of the liquid will be reduced due to the electrolyte contained in the positive plate 11, or the discharge path between the electrode 117 and the separator 19 will increase, thereby weakening the shock wave.

[0047] Furthermore, when metal fragments constituting the peeling device 101 are scattered by energization, the metal may be mixed in. For example, when the separator 119 is made of stainless steel, iron and chromium may be mixed in mainly.

[0048] In this embodiment, since the current-carrying region 111 and the shock wave transmission region 113 are separated, the metal constituting the separator 119 is not mixed in by the shock wave, and the positive electrode current collector 31 and the positive electrode composite material 32 can be effectively separated.

[0049] [Structure supported by the above-mentioned embodiment]

[0050] The above-described embodiment supports the following structure.

[0051] (Structure 1) A stripping device for stripping a positive electrode collector from a positive electrode composite material, comprising: a power-carrying area having an electrode; a shock wave transmission area accommodating a positive electrode plate; an isolation plate separating the areas; and a power supply device that supplies power to the electrode, discharges back between the electrode and the isolation plate, transmits the shock wave generated in the power-carrying area to the positive electrode plate in the shock wave transmission area via the isolation plate, and strips the positive electrode composite material from the positive electrode collector of the positive electrode plate.

[0052] According to Structure 1, the electrode, which generates the shock wave, is isolated from the positive electrode plate. Therefore, the composition of the positive electrode plate does not affect the conduction of electricity in the current-carrying area. Furthermore, this prevents materials from entering the shock wave transmission area from the current-carrying area. Consequently, the positive electrode current collector and the positive electrode composite material can be effectively separated.

[0053] (Structure 2) In the peeling device for peeling the positive electrode current collector and the positive electrode composite material according to Structure 1, the separator is a plate made of stainless steel.

[0054] According to the second configuration, substances are prevented from entering the shock wave transmission region from the current-carrying region, and thus it is possible to suppress the infiltration of stainless steel into the positive electrode current collector or the positive electrode composite material.

[0055] (Structure 3) In the peeling device for peeling the positive electrode current collector and the positive electrode composite material according to Structure 1 or 2, the current-carrying area is filled with a liquid having a high dielectric breakdown limit.

[0056] According to the third configuration, since the current conduction path is not dispersed, the power of the shock wave is stabilized, and efficient peeling can be performed.

[0057] (Structure 4) In the peeling device for peeling the positive electrode current collector and the positive electrode composite material according to Structure 1, the current-carrying area is filled with an organic liquid such as water or oil.

[0058] According to the fourth configuration, the current path is not dispersed, so the power of the shock wave is stabilized, and efficient peeling can be performed.

[0059] (Structure 5) In the peeling device for peeling the positive electrode current collector and the positive electrode composite material according to Structure 1, the shock wave transmission region is filled with water.

[0060] According to the configuration 5, the positive electrode plate can be placed and recovered very easily.

Claims

1. A stripping device for stripping a positive electrode current collector from a positive electrode composite material, comprising: an energized region having electrodes; a shock wave transmission area, which houses the positive plate; Isolation panels that separate the areas; and a power supply device that provides power to the electrodes, The shock wave generated in the energized area is transmitted to the positive electrode plate in the shock wave transmission area via the separator, so that the positive electrode composite material is peeled off from the positive electrode collector of the positive electrode plate.

2. The device for peeling a positive electrode current collector from a positive electrode composite material according to claim 1, wherein: The isolation plate is a plate made of stainless steel.

3. The stripping device for stripping a positive electrode current collector and a positive electrode composite material according to claim 1, wherein: The current-carrying area is filled with a liquid having a high dielectric breakdown limit.

4. The device for peeling a positive electrode current collector from a positive electrode composite material according to claim 1, wherein: The electrified area is filled with water, oil, or other organic liquids.

5. The device for peeling a positive electrode current collector from a positive electrode composite material according to claim 1, wherein: The shock wave transmission area is filled with water.

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