Peeling device for positive electrode collector and positive electrode mixture

Abstract

To efficiently separate a positive electrode collector and a positive electrode mixture from each other.SOLUTION: A peeling device for a positive electrode collector and a positive electrode mixture comprises an energization area comprising an electrode, a shock wave transmission area housing positive electrode plates, a separator partitioning each of the areas, and a power supply device applying power to the electrode. The peeling device discharges electricity between the electrode and the separator, transmits a shock wave generated in the energization area to the positive electrode plate in the shock wave transmission area through the separator, and peels the positive electrode mixture from the positive electrode collector of the positive electrode plate.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a device for separating a positive electrode current collector from a positive electrode mixture. [Background technology]

[0002] Some lithium-ion batteries and all-solid-state batteries have laminated electrodes in which positive and negative electrodes are stacked with a separator between them. The positive electrode plate of this type of battery is composed of a positive electrode current collector and a positive electrode composite. The positive electrode composite is made of a ternary positive electrode material (NCM) consisting of nickel, cobalt, and manganese. When disposing of batteries, it is desirable to recover valuable metals such as NCM. The positive electrode composite is bonded to aluminum foil, which serves as the positive electrode current collector, by the binder contained in the positive electrode composite. Conventionally, a technique has been known in which a cut piece of a positive electrode plate made of aluminum foil and a positive electrode composite is placed in water, and shock waves are generated in the water by electric pulse discharge to separate different materials (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2023-086495 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, as in Patent Document 1, when a cut piece of a positive electrode plate is placed in water and a shock wave is generated in the water by an electric pulse discharge, the positive electrode plate contains an electrolyte, which improves the electrical conductivity of the water and weakens the dielectric breakdown strength, thereby weakening the power of the shock wave. Furthermore, there is a risk that a part of the container in which the positive electrode plate is placed may be shattered by the shock wave of the electric pulse discharge, resulting in contamination of the metal of the container. The present invention has been made in view of the above circumstances, and has an object to effectively separate a positive electrode current collector and a positive electrode mixture. [Means for solving the problem]

[0005] The device for peeling a positive electrode current collector and a positive electrode composite in the present invention comprises a current-carrying area having an electrode, a shock wave transmission area that houses a positive electrode plate, a separator that separates the areas, and a power supply device that supplies power to the electrode. Electrical discharge occurs between the electrode and the separator, and shock waves generated in the current-carrying area are transmitted via the separator to the positive electrode plate in the shock wave transmission area, thereby peeling the positive electrode composite from the positive electrode current collector of the positive electrode plate. [Effects of the Invention]

[0006] The present invention provides a device for separating a positive electrode current collector from a positive electrode composite material, which can effectively separate the positive electrode current collector from the positive electrode composite material. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a diagram schematically illustrating a target battery to which the battery treatment method of the present invention can be applied. [Figure 2] FIG. 2 is a schematic diagram of a device for separating a positive electrode current collector and a positive electrode composite material. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. (Embodiment) [1. Target battery configuration] FIG. 1 is a diagram showing the configuration of a target battery 10 as an example of a battery to which the present disclosure is applied, and schematically shows a cross section of the target battery 10. The target battery 10 is a secondary battery capable of charging and discharging. The target battery 10 described in this embodiment is a laminated battery in which battery materials are encapsulated in a laminate material 22, and has an overall flat plate shape. The target battery 10 can be referred to as a pouch-type battery, a laminated battery cell, a pouch-type battery cell, a lithium-ion battery cell, a battery module, or the like.

[0009] The subject battery 10 is a secondary battery known as a lithium-ion battery, which has attracted attention as an energy storage device with a high energy density. Positive electrode active materials for lithium-ion batteries include, for example, lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, and lithium iron phosphate. Positive electrode active materials include ternary cathode materials (NCMs) containing nickel, cobalt, and manganese. Negative electrode active materials for lithium-ion batteries include, for example, carbon-based materials. All-solid-state batteries, which use a solid electrolyte as the electrolyte for lithium-ion batteries, are also known.

[0010] Nickel, cobalt, and manganese, which are used as positive electrode active materials in lithium-ion batteries and all-solid-state batteries, are known as valuable metals and there is a demand for their recovery from used batteries.

[0011] 1, the target battery 10 has a configuration in which a laminated electrode 21 is housed in a laminate material 22. The laminate material 22 is a laminate film whose base material is a metal material such as an aluminum alloy or stainless steel. The laminate material 22 functions as an exterior body of the target battery 10 and as a seal that seals the laminated electrode 21.

[0012] The target battery 10 of this embodiment has a flat plate shape formed by bonding two sheets of laminate material 22 together, and a pair of current collecting tabs 23A, 23B for extracting power from the target battery 10 penetrate the outer casing and are exposed from the end of the target battery 10.

[0013] The laminated electrode 21 is a multilayer body in which positive electrode plates 11 and negative electrode plates 12 are stacked, and a separator 13 is disposed between each positive electrode plate 11 and negative electrode plate 12. The separator 13 is disposed between the positive electrode plate 11 and the negative electrode plate 12 to prevent a short circuit between the positive electrode plate 11 and the negative electrode plate 12.

[0014] The positive electrode plates 11 and the negative electrode plates 12 are arranged alternately, 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.

[0015] The positive electrode plate 11 includes a rectangular plate-shaped positive electrode collector 31, and a positive electrode composite 32 is provided on both sides of the positive electrode collector 31. The positive electrode collector 31 is an aluminum alloy or pure aluminum material formed into a foil or plate shape. The positive electrode composite 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 electrode terminal 11A extending from an end of the positive electrode plate 11. The positive electrode terminals 11A extending from the multiple positive electrode plates 11 constituting the stacked electrode 21 are each connected to a current collecting tab 23A.

[0016] 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. The negative electrode current collector 41 is made of, for example, copper foil. The negative electrode plate 12 has a negative electrode terminal 12A that extends from an end of the negative electrode plate 12. The negative electrode terminals 12A that extend from the multiple negative electrode plates 12 that make up the stacked electrode 21 are each connected to a current collecting tab 23B.

[0017] The current collecting tabs 23A and 23B are formed from a thin metal plate such as copper or aluminum, and pass between the two laminate materials 22 and are exposed to the outside.

[0018] If the target battery 10 is a lithium-ion battery, the laminate material 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 carbonate esters such as ethylene carbonate, dimethyl carbonate, diethyl carbonate, and vinylene carbonate. These are just some examples, and the electrolyte, solvent, and additive can be selected and changed as appropriate.

[0019] When the target battery 10 is an all-solid-state battery, a solid electrolyte is disposed inside the laminate material 22. Although oxide-based electrolytes and sulfide-based electrolytes are known as solid electrolytes, the present disclosure may also be applicable to all-solid-state batteries using other materials. The solid electrolyte of the all-solid-state battery is disposed, for example, 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-circuiting between the positive electrode plate 11 and the negative electrode plate 12.

[0020] [2. Peeling device] FIG. 2 is a schematic diagram of a device 101 for separating the positive electrode current collector 31 and the positive electrode composite material 32. As shown in FIG. The peeling device 101 includes a power supply 102 that generates electric power. The power supply 102 instantaneously outputs a large amount of high-voltage power for a short period of time, such as microseconds or nanoseconds. The main body of the power supply 2 is covered by a Faraday cage 8 that provides electromagnetic shielding. The power supply 102 has, for example, a capacitor that stores a predetermined charge and instantaneously discharges it. The power supply 102 has an output terminal 105 that outputs a pulse voltage. The power supply 102 is connected to an electrical ground E that electrically connects the power supply 102 to the earth. The power supply 2 has a ground terminal 107 that is connected to the electrical ground E.

[0021] The peeling device 101 includes an apparatus main body 103. The apparatus main body 103 is a hollow container made of a metal such as stainless steel. The apparatus main body 103 is shown in partial cross section in FIG. 2. The hollow interior of the apparatus main body 103 is partitioned by a separator 119. The separator 119 is a grounded flat plate made of a metal such as stainless steel. In this embodiment, the upper part of the separator 119 constitutes a conducting area 111 that generates shock waves, and the lower part of the separator 119 constitutes a shock wave transmission area 113 that transmits the shock waves to the positive electrode plate 11.

[0022] The current-carrying area 111 has an electrode support portion 115 at its upper portion and an electrode 117 supported at the lower end of the electrode support portion 115. The 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 area 111 is filled with an organic liquid (first liquid X) such as water or oil. The separator 119 is electrically connected to the ground terminal 107 of the power supply device 102.

[0023] The separation space 123 in the shock wave transmission area 113 is filled with a liquid (second liquid Y) such as water. 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, and a plurality of positive electrode plates 11 are disposed in the separation space 123 in a vertically stacked state.

[0024] In the peeling device 101, when the electric field strength generated by the power supply device 102 exceeds the dielectric breakdown limit of the first liquid X filled in the current-carrying area 111, a discharge occurs between the electrode 117 and the separator 119 in the current-carrying area 111, generating a shock wave. The shock wave generated in the energized area 111 propagates through the separator 119 to the second liquid Y in the shock wave transmission area 113 .

[0025] [3. Operation and Effects] Next, we will explain the operation and effect of peeling the positive electrode composite 32 from the positive electrode current collector 31 of the positive electrode plate 11. The positive electrode plate 11 is separated from the target battery 10 by a known technique and placed in the shock wave transmission area 113.

[0026] When a discharge occurs between the electrode 117 and the separator 119, the first liquid X in the discharge path momentarily turns into bubbles, generating a shock wave. The 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. When current is repeatedly applied by the power supply 102, discharges occur repeatedly in the discharge path, generating shock waves that peel the positive electrode composite 32 from the positive electrode current collector 31 of the positive electrode plate 11. After the peeling is completed after a predetermined number of cycles of current application, the shock wave transmission area 113 is removed, and the water inside and the peeled positive electrode current collector 31 and positive electrode composite 32 are sorted and collected.

[0027] By filling shock wave transmission area 113 with water again, placing positive electrode plate 11 thereon, and repeatedly energizing power supply 102, positive electrode mixture 32 can be continuously peeled off from positive electrode current collector 31.

[0028] The first liquid X is preferably a liquid that easily conducts shock waves so as not to attenuate the energy of the shock waves. For example, a liquid with a density greater than that of water is suitable. The first liquid X is preferably a liquid with high dielectric strength so as to increase the energy of the shock waves. Furthermore, since the dielectric strength of the first liquid X decreases when the metal forming the separator 119 dissolves, it is preferable that the first liquid X have a lower solubility of the metal than water. When current is applied, the metal on the surface of the separator 119 may be fractured by the impact force, so the metal is particularly likely to dissolve within the current-carrying area 111. From these viewpoints, the first liquid X is preferably an organic liquid.

[0029] Furthermore, if the peeling device 101 were configured such that the current-carrying area 111 and the shock wave transmission area 113 were integrated, the electrolyte contained in the positive electrode plate 11 would reduce the dielectric breakdown strength of the liquid or increase the discharge path between the electrode 117 and the separator 19, thereby weakening the shock wave.

[0030] Furthermore, if metal fragments that constitute the separation device 101 fly off due to energization, the metals will become mixed in. For example, if the separator 119 is made of stainless steel, the metals that will become mixed in will be mainly iron and chromium. In this embodiment, the current-carrying area 111 and the shock wave transmission area 113 are separated, so that the shock waves do not cause the metal constituting the separator 119 to become mixed in, and the positive electrode current collector 31 and the positive electrode composite 32 can be effectively separated.

[0031] [Configuration supported by the above embodiment] The above embodiment supports the following configurations.

[0032] (Configuration 1) A device for peeling a positive electrode current collector and a positive electrode composite, comprising: a current-carrying area having an electrode; a shock wave transmission area that houses a positive electrode plate; a separator that separates the areas; and a power supply device that supplies power to the electrode, wherein discharge occurs between the electrode and the separator, and shock waves generated in the current-carrying area are transmitted via the separator to the positive electrode plate in the shock wave transmission area, thereby peeling a positive electrode composite from the positive electrode current collector of the positive electrode plate. According to the first configuration, the electrode that generates the shock wave is isolated from the positive electrode plate. Therefore, the components of the positive electrode plate do not affect the current flow in the current-carrying area. Furthermore, the infiltration of substances from the current-carrying area into the shock wave transmission area can be prevented. Therefore, the positive electrode current collector and the positive electrode composite can be effectively separated.

[0033] (Configuration 2) The apparatus for separating a positive electrode current collector from a positive electrode composite according to configuration 1, wherein the separator is a plate made of stainless steel. According to the second aspect, since it is possible to prevent the intrusion of substances from the current-carrying area into the shock wave transmission area, it is possible to suppress the intrusion of stainless steel into the positive electrode current collector or the positive electrode composite material.

[0034] (Configuration 3) The device for separating a positive electrode current collector from a positive electrode composite material according to Configuration 1 or 2, wherein the current-carrying area is filled with a liquid having a high dielectric breakdown limit. According to the third aspect, the current path is not dispersed, so the power of the shock wave is stable, and efficient peeling can be performed.

[0035] (Configuration 4) The apparatus for separating a positive electrode current collector and a positive electrode composite according to Configuration 1, wherein the current-carrying area is filled with water or an organic liquid such as oil. According to the fourth aspect, the current path is not dispersed, so the power of the shock wave is stable, and efficient peeling can be performed.

[0036] (Configuration 5) The apparatus for peeling off a positive electrode current collector and a positive electrode composite according to Configuration 1, wherein the shock wave transmission area is filled with water. According to the fifth aspect, the positive electrode plate can be easily placed and removed. [Explanation of symbols]

[0037] 10...target battery, 11...positive electrode plate, 12...negative electrode plate, 13...separator, 21...laminated electrode, 22...laminate material, 22A, 22B...current collecting tab, 31...positive electrode current collector, 32...positive electrode composite, 41...negative electrode current collector, 42...negative electrode composite, 101...peeling device, 102...power supply device, 103...device main body, 105...output terminal, 107...ground terminal, 111...current carrying area, 113...shock wave transmission area, 115...electrode support part, 117...electrode, 119...separator, 121...current carrying space, 123...peeling space, E...electrical ground, X...first liquid, Y...second liquid.

Claims

1. a current carrying area having an electrode; a shock wave transmission area housing the positive electrode plate; Separators separating each area, a power supply for powering the electrodes; Equipped with Discharge occurs between the electrode and the separator, and shock waves generated in the current-carrying area are transmitted to the positive electrode plate in the shock wave transmission area via the separator, thereby peeling off the positive electrode composite from the positive electrode current collector of the positive electrode plate. A device for peeling off the positive electrode current collector and positive electrode composite material.

2. The separator is a stainless steel plate. The device for separating a positive electrode current collector and a positive electrode mixture according to claim 1 .

3. The current-carrying area is filled with a liquid having a high dielectric breakdown limit. The device for separating a positive electrode current collector and a positive electrode mixture according to claim 1 .

4. The current carrying area is filled with water or an organic liquid such as oil. The device for separating a positive electrode current collector and a positive electrode mixture according to claim 1 .

5. The shock wave transmission area is filled with water. The device for separating a positive electrode current collector and a positive electrode mixture according to claim 1 .

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