Method for recovering electrode materials

Abstract

To provide a method for recovering an electrode material.SOLUTION: A method for recovering an electrode material 13a of the present disclosure includes the following steps: providing an electrode laminate roll 21 in which an electrode laminate 11 is wound, the electrode laminate 11 including a current collector foil 12 and an electrode material 13 laminated on at least one surface of the current collector foil 12; unwinding the electrode laminate 11 from the electrode laminate roll 21 and transporting the electrode laminate in a longitudinal direction; and crushing the electrode material 13 and separating the electrode material from the current collector foil, by spraying dry ice particles 31 onto the electrode laminate 11 during transport.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for recovering an electrode material. [Background technology]

[0002] It has been considered to disassemble primary or secondary batteries such as lithium-ion batteries after use, and recover and recycle the electrode materials such as the positive electrode mixture (positive electrode active material) and the negative electrode mixture (negative electrode active material).

[0003] Patent Document 1 discloses a method for recovering a catalyst from an object having a catalyst layer formed on the surface of an electrolyte membrane or diffusion layer for a fuel cell. The method includes a step of exfoliating the catalyst from the electrolyte membrane or diffusion layer by colliding a group of solid particles such as dry ice particles or ice particles against the catalyst layer formed on the surface of the electrolyte membrane or diffusion layer, and a step of recovering the exfoliated catalyst. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2006-95367 A Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, after the use of a primary battery or a secondary battery, it has been considered to disassemble the battery, recover the electrode material, and recycle the battery. However, in the manufacturing stage of a primary battery or a secondary battery, when an electrode material is laminated on a current collector foil to form an electrode laminate, defects may occur, and the obtained electrode laminate may become unusable. The present disclosure et al. have found that it is preferable to recover the electrode material from the unusable electrode laminate generated in the manufacturing stage of the battery.

[0006] The present disclosure has been made in view of these points and provides a method for recovering electrode materials. [Means for solving the problem]

[0007] <Aspect 1> A method for recovering an electrode material, comprising the steps of: providing an electrode laminate roll in which an electrode laminate is wound, the electrode laminate having a current collector foil and an electrode material laminated on at least one surface of the current collector foil; unwinding the electrode laminate from the electrode laminate roll and transporting it in a longitudinal direction; and Dry ice particles are sprayed onto the electrode laminate during transportation to crush the electrode material and separate the electrode material from the current collecting foil. <Aspect 2> 2. The method of claim 1, further comprising blowing a gas onto the electrode stack simultaneously with or after blowing the dry ice particles onto the electrode stack. <Aspect 3> The method according to aspect 1 or 2, further comprising providing touch rolls for adjusting the tension of the electrode laminate upstream of the position where the dry ice particles are blown onto the electrode laminate and downstream of the position where the dry ice particles are blown onto the electrode laminate, thereby applying tension to the electrode laminate at the position where the dry ice particles are blown onto the electrode laminate. <Aspect 4> The electrode material is laminated on both sides of the current collector foil; and The dry ice particles are sprayed onto both sides of the electrode stack. The method according to any one of aspects 1 to 3. <Aspect 5> The method of any one of embodiment 2, embodiment 3 reciting embodiment 2, embodiment 4 reciting embodiment 2, and embodiment 4 reciting embodiment 3 reciting embodiment 2, wherein the gas is dry air or nitrogen gas. <Aspect 6> The method of any one of embodiment 2, embodiment 3 which recites embodiment 2, embodiment 4 which recites embodiment 2, embodiment 4 which recites embodiment 3 which recites embodiment 2, or embodiment 5, wherein the gas is a heated gas. <Aspect 7> 7. The method of any one of aspects 1 to 6, further comprising winding up the current collector foil from which the electrode material has been separated onto a take-up roll to provide a current collector foil roll. Effect of the Invention

[0008] According to the present disclosure, a method for recovering an electrode material can be provided. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram illustrating one embodiment of the method of the present disclosure for recovering an electrode material. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The method of recovering an electrode material according to the present disclosure may be a method of recovering an electrode material of a primary or secondary battery, for example, a lithium ion primary or secondary battery, by separating it from a current collector foil. In the method of the present disclosure, the electrode material to be recovered includes a positive electrode active material, a negative electrode active material, a conductive assistant, a binder, etc., and may be a single material or a combination of a plurality of materials such as a composite material. Therefore, according to the method of the present disclosure, a positive electrode active material or a negative electrode active material, particularly a positive electrode active material, can be recovered and recycled.

[0011] Fig. 1 is a schematic diagram illustrating one embodiment of the method of the present disclosure for recovering an electrode material. In the following, the method of the present disclosure shown in Fig. 1 will be specifically described, but the method of the present disclosure is not limited to this embodiment.

[0012] (Provision of electrode laminate rolls) In the method of the present disclosure, an electrode laminate roll 21 is provided in which an electrode laminate 11 is wound up. The electrode laminate has a current collector foil 12 and an electrode material 13 laminated on at least one surface of the current collector foil.

[0013] The current collector foil may be, for example, a metal foil containing aluminum. The metal foil may be an aluminum foil, a metal foil such as SUS, Cu, Ni, Fe, Ti, Co, or Zn, a foil using a clad material of a metal such as SUS, Cu, Ni, Fe, Ti, Co, or Zn with Al, or a foil whose metal surface is coated with Al.

[0014] The electrode material may be a positive electrode mixture (positive electrode active material) or a negative electrode mixture (negative electrode active material), and may be a positive electrode mixture in particular. For example, the positive electrode mixture may include an oxide active material, a sulfide active material, or the like. The electrode material may also include a binder such as PESE (polyethylene sebacate), PPSU (polyphenylsulfone), PBI (polybenzimidazole), or PESU (polyethersulfone). The electrode material may also include a carbon material such as acetylene black, furnace black, channel black, thermal black, activated carbon, carbon, carbon fiber, or graphite.

[0015] (Unwinding from the electrode laminate roll) In the method of the present disclosure, the electrode laminate 11 is unwound from the electrode laminate roll 21 and transported in the longitudinal direction. Note that, in the present disclosure, the "longitudinal direction" means the length direction of the electrode laminate 11, i.e., the direction in which the electrode laminate 11 is wound around the electrode laminate roll 21.

[0016] The electrode laminate can be unwound from the electrode laminate roll by any known method, for example, by rotating the electrode laminate roll using a motor, and the unwound electrode laminate can be transported while being supported by a support roller or suspended in the air.

[0017] (Separation of electrode materials) In the method of the present disclosure, dry ice particles 31 are sprayed onto the electrode laminate 11 during transportation, thereby crushing the electrode material 13 and separating it from the current collector foil 12.

[0018] The particle size of the dry ice particles to be sprayed onto the electrode laminate is not particularly limited, but may be, for example, 1 to 100 μm. The spray speed of the dry ice particles 31 is not particularly limited, but may be, for example, 20 to 200 m / s. In the present disclosure, the particle size can be defined as the average value of the maximum diameter when the particles are observed under a microscope.

[0019] By spraying the dry ice particles 31, the dry ice particles collide with the electrode material, and the electrode material is crushed by the impact, and the electrode material is separated (peeled off) from the current collecting foil. In addition, since the dry ice particles are low temperature, the electrode laminate 11 is cooled by spraying the dry ice particles 31, and the resin component in the electrode material shrinks, hardens, and becomes embrittled, thereby promoting the crushing of the electrode material and the separation of the electrode material from the current collecting foil. This treatment can be performed under an inert gas atmosphere, particularly under a nitrogen atmosphere or a carbon dioxide atmosphere. Here, the carbon dioxide atmosphere can also be obtained by carbon dioxide generated from dry ice. When this treatment is performed under an inert gas atmosphere, the deterioration of the active material contained in the electrode material can be suppressed. In addition, when this treatment is performed under a carbon dioxide active atmosphere, metallic lithium and the like contained in the electrode material can be carbonated with carbon dioxide and stabilized.

[0020] A gas may be blown onto the electrode stack at the same time as or after the dry ice particles are blown onto the electrode stack, which can promote sublimation of any dry ice remaining on the electrode stack, thereby promoting the fragmentation of the electrode material and the separation of the electrode material from the electrode stack.

[0021] The gas blown onto the electrode stack may be dry air, i.e., air that has been treated to remove moisture. The gas may be nitrogen gas. The gas may also be heated gas. Here, heated gas does not necessarily mean high-temperature gas, but means gas that has been heated even slightly. If the gas is heated gas, it is preferable because the dry ice will be easily sublimated.

[0022] The electrode materials 13, 13a peeled off from the current collecting foil are separated from the current collecting foil by spraying dry ice particles 31 onto the electrode material. The separated materials are blown away by the sprayed dry ice particles 31 and, optionally, by the sprayed gas 32, leaving only the current collecting foil 12 from which the electrode material has been peeled off.

[0023] The dry ice particles and gas may be sprayed onto one or both sides of the electrode laminate. When dry ice particles and, optionally, gas are sprayed onto both sides, the temperature difference between the two sides is reduced, making it difficult for wrinkles (unevenness) to occur in the current collector foil.

[0024] (Application of tension) A touch roll 41 for adjusting the tension of the electrode laminate 11 may be provided upstream of the position where the dry ice particles 31 are blown onto the electrode laminate 11, and downstream of the position where the dry ice particles 31 are blown onto the electrode laminate 11, thereby applying tension to the electrode laminate 11 at the position where the dry ice particles 31 and gas 32 are blown onto the electrode laminate 11.

[0025] The application of such tension is preferable in order to suppress flapping of the electrode laminate when the dry ice particles are blown onto the electrode laminate. The downstream touch roll 41 may be located downstream of the position where the gas 32 is blown onto the electrode laminate 11.

[0026] (Winding of current collecting foil) The current collector foil 12 from which the electrode material has been peeled off may be wound up on a winding roll 22 to form a current collector foil roll. The wound current collector foil, from which the electrode material has been removed, may be reused as metal foil.

[0027] The electrode material 13a separated from the current collector foil 12 may be, for example, dropped and collected separately. The collected electrode material may be reslurried by adding a solution such as NMP (N-methyl-2-pyrrolidone) solution to the electrode material 13a as it is or after treatment such as washing and purification, and may be used again for coating of the electrode material.

[0028] Although one embodiment of the present disclosure has been described in detail above, the present disclosure is not limited to the above-described embodiment, and various design modifications can be made without departing from the spirit of the present disclosure. [Explanation of symbols]

[0029] 11 Electrode laminate 12 Current collecting foil 13, 13a Electrode material 21 Electrode laminate roll 22 Winding roll 31 Dry Ice Particles 32 Gas 41 Touch Roll

Claims

1. A method for recovering an electrode material, comprising the steps of: providing an electrode laminate roll in which an electrode laminate is wound, the electrode laminate having a current collector foil and an electrode material laminated on at least one surface of the current collector foil; unwinding the electrode laminate from the electrode laminate roll and transporting it in a longitudinal direction; and Dry ice particles are sprayed onto the electrode laminate during transportation to crush the electrode material and separate the electrode material from the current collecting foil.

2. The method according to claim 1 , further comprising blowing a gas onto the electrode stack simultaneously with or after blowing the dry ice particles onto the electrode stack.

3. 3. The method according to claim 1, further comprising: a touch roll for adjusting the tension of the electrode laminate, the touch roll being provided upstream of the position where the dry ice particles are blown onto the electrode laminate and downstream of the position where the dry ice particles are blown onto the electrode laminate, thereby applying tension to the electrode laminate at the position where the dry ice particles are blown onto the electrode laminate.

4. The electrode material is laminated on both sides of the current collector foil; and The dry ice particles are sprayed onto both sides of the electrode stack. The method according to claim 1 or 2.

5. The method of claim 2 , wherein the gas is dry air or nitrogen gas.

6. The method of claim 2 , wherein the gas is a heated gas.

7. The method of claim 1 or 2, further comprising winding the current collector foil from which the electrode material has been separated onto a take-up roll to provide a current collector foil roll.

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