Battery disposal method

Abstract

This disclosure aims to provide a method for easily and safely disposing of batteries. [Solution] A battery processing method according to one aspect of the present disclosure comprises a step of deactivating a battery, a step of pulverizing the deactivated battery, a first separation step of separating a negative electrode active material and a negative electrode conductive additive from the negative electrode layer of the pulverized battery, and a second separation step of separating a positive electrode active material and a positive electrode conductive additive from the positive electrode layer of the pulverized battery, wherein the deactivation step, the pulverization step, the first separation step and the second separation step are performed in a solvent.

Description

Technical Field

[0001] The present disclosure relates to a battery processing method, and particularly to a method for efficiently and safely processing in a continuous wet process in the battery recycling process.

Background Art

[0002] In recent years, the use of secondary batteries has expanded, and from the perspective of resource recycling, there is a demand for technology to efficiently process used secondary batteries. For example, a method for processing lithium-ion secondary batteries has been invented (Japanese Patent Laid-Open No. 2021-150282).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the method for processing lithium-ion secondary batteries described in the above publication, the lithium-ion secondary batteries with residual voltage are burned and crushed, and lithium and the like are recovered. By heating the lithium-ion secondary batteries with residual voltage at a relatively low temperature and causing combustion due to the self-heating of the lithium-ion secondary batteries themselves, it is said that energy can be saved and heat treatment can be performed. In this processing method, since heat treatment by a roasting furnace or the like, crushing by a hammer crusher or the like, and classification of the crushed material by a vibrating screen or the like are performed, the processing work may become complicated. It is desired to process the battery easily and safely.

[0005] The present disclosure has been made based on the above circumstances, and an object thereof is to provide a method for easily and safely processing a battery.

Means for Solving the Problems

[0006] A battery processing method, one aspect of the present disclosure made to solve the above problems, comprises a step of deactivating a battery, a step of pulverizing the deactivated battery, a first separation step of separating a negative electrode active material and a negative electrode conductive additive from the negative electrode layer of the pulverized battery, and a second separation step of separating a positive electrode active material and a positive electrode conductive additive from the positive electrode layer of the pulverized battery, wherein the deactivation step, the pulverization step, the first separation step and the second separation step are performed in a solvent. [Effects of the Invention]

[0007] One embodiment of the present disclosure is a battery processing method that allows for easy and safe processing of batteries. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic side view showing an example of equipment for performing a battery processing method according to one embodiment of the present disclosure. [Figure 2] Figure 2 is a schematic side view showing equipment different from that in Figure 1. [Figure 3] Figure 3 is a schematic side view showing equipment different from that in Figures 1 and 2. [Figure 4] Figure 4 is a schematic side view showing equipment different from that shown in Figures 1, 2, and 3. [Figure 5] Figure 5 is a schematic side view showing equipment different from that shown in Figures 1 through 4. [Modes for carrying out the invention]

[0009] [Description of Embodiments in this Disclosure] First, the embodiments of this disclosure will be listed and described.

[0010] (1) A battery processing method according to one aspect of the present disclosure comprises a step of deactivating a battery, a step of pulverizing the deactivated battery, a first separation step of separating a negative electrode active material and a negative electrode conductive additive from the negative electrode layer of the pulverized battery, and a second separation step of separating a positive electrode active material and a positive electrode conductive additive from the positive electrode layer of the pulverized battery, wherein the deactivation step, the pulverization step, the first separation step and the second separation step are performed in a solvent.

[0011] This battery processing method allows for easy and safe disposal of batteries because it performs each of the above steps in a solvent without burning the batteries.

[0012] (2) In (1) above, the deactivation step, the pulverization step and the first separation step may be carried out in a first solvent, and the second separation step may be carried out in a second solvent. The efficiency of processing the battery can be improved by using different solvents for the deactivation step, the pulverization step and the first separation step and the solvent used for the second separation step.

[0013] (3) In (1) or (2) above, the deactivation step may be carried out in one tank, the pulverization step in another tank, and the first separation step in yet another tank. By carrying out the deactivation step, the pulverization step and the first separation step in different tanks, the batteries can be processed reliably.

[0014] (4) In (1) or (2) above, the deactivation step and the pulverization step may be carried out in one tank, and the first separation step may be carried out in another tank. By carrying out the deactivation step and the pulverization step in one tank, the efficiency of processing the batteries can be further improved.

[0015] (5) In (1) or (2) above, the deactivation step, the crushing step and the first separation step may be carried out in a single tank. By carrying out the deactivation step, the crushing step and the first separation step in a single tank, the efficiency of processing the batteries can be further improved.

[0016] (6) In the above (1), the deactivation step and the pulverization step may be performed in a first solvent, and the first separation step and the second separation step may be performed in a second solvent. By using different solvents in the deactivation step and the pulverization step and in the first separation step and the second separation step, the efficiency of processing the battery can be improved.

[0017] (7) In any one of the above (2) to (6), the first solvent may be water or brine, and the second solvent may be NMP. By using water or brine as the first solvent and NMP (N-Methyl-2-Pyrrolidone) as the second solvent, the efficiency of processing the battery can be further improved.

[0018] [Details of the Embodiment for Implementing the Present Disclosure] Next, the present disclosure will be described in detail with reference to the drawings.

[0019] <Battery Processing Method> The battery processing method includes a step of deactivating a battery, a step of pulverizing the deactivated battery, a first separation step of separating a negative electrode active material and a negative electrode conductive assistant from a negative electrode layer of the pulverized battery, and a second separation step of separating a positive electrode active material and a positive electrode conductive assistant from a positive electrode layer of the pulverized battery. The deactivation step, the pulverization step, the first separation step, and the second separation step are performed in a solvent. Since the battery processing method performs each of the above steps in the solvent, the battery can be processed easily and safely. If the battery is burned or the like, there is a risk of ignition, explosion, etc. of the battery. However, since the battery processing method performs all the processes in a so-called wet manner, the battery can be processed easily and safely.

[0020] 〔Battery〕 The battery to be processed by the battery processing method (hereinafter also referred to as the battery to be processed) is not particularly limited, and examples thereof include storage batteries such as lithium ion secondary batteries. Further, the battery to be processed may be formed in a substantially rectangular parallelepiped shape, cylindrical shape, etc. with a rigid housing, or may be formed in a bag shape by laminating a flexible sheet-like member. The battery to be processed may be a all-solid-state battery.

[0021] The form of the battery to be processed is not particularly limited, and it may be a single battery (a single cell), a battery module composed of a plurality of batteries, or a battery pack including a plurality of batteries or a plurality of battery modules in a casing. The battery to be processed may be a battery that has been used and discarded, a battery that has failed in the quality inspection after manufacture (unused defective product), or an unused non-defective product.

[0022] 〔Solvent〕 The above solvent is not particularly limited as long as each process can be efficiently performed, and different solvents may be used in each process, the same solvent may be used in all processes, or the same solvent may be used in some of the plurality of processes and different solvents may be used in the remaining processes. The above solvent may be selected according to the physical properties of the constituent members of the battery to be processed, the efficiency in the treatment of each process, etc.

[0023] For example, in the above deactivation step, the above pulverization step and the above first separation step, a first solvent may be used, and in the above second separation step, a second solvent different from the above first solvent may be used. Alternatively, a first solvent may be used in the above deactivation step and the above pulverization step, and a second solvent may be used in the above first separation step and the above second separation step.

[0024] The first solvent is preferably an inorganic solvent, such as water, an aqueous solution of an inorganic salt, or especially brine. The deactivation step and the pulverization step are preferably carried out in the first solvent. By carrying out the deactivation step and the pulverization step in water or an aqueous solution of an inorganic salt, the heat generation of the battery being processed can be suppressed, thereby preventing ignition, explosion, etc. Furthermore, if the battery being processed uses an aqueous binder as the binder for the negative electrode active material, the first separation step is preferably carried out in the first solvent. By carrying out the first separation step in the first solvent, the negative electrode active material and the negative electrode conductive additive can be efficiently recovered.

[0025] The second solvent is preferably an organic solvent, such as NMP. When the battery to be processed uses a PVDF (Poly Vinylidene DiFluoride) binder for the positive electrode active material, the second separation step is preferably carried out in the second solvent. By pulverizing the battery containing the PVDF binder in the positive electrode and processing it in the second solvent, the positive electrode active material and the positive electrode conductive additive can be efficiently recovered. Furthermore, when the battery to be processed uses a PVDF binder for the negative electrode active material, the first separation step is preferably carried out in the second solvent. By pulverizing the battery containing the PVDF binder in the negative electrode and processing it in the second solvent, the negative electrode active material and the negative electrode conductive additive can be efficiently recovered.

[0026] [Inactivation process] In this battery processing method, the battery is deactivated in the solvent described above. Specifically, for example, as shown in Figure 1, the battery B1 to be processed may be immersed in the first solvent M1 stored in a tank (deactivation tank) 11.

[0027] [The grinding process] In the above-described grinding step, the deactivated battery is ground in the solvent. The means of grinding are not particularly limited, and a known crusher 20 may be used. Specifically, for example, the deactivated battery to be processed (deactivated battery) B1 may be put into another tank (grinding tank) 12 that stores the first solvent M1, and the deactivated battery 1 may be ground in the first solvent M1. The means of putting in the deactivated battery 1 are not particularly limited, for example, the deactivated battery 1 may be taken out of the deactivation tank 11 and put into the crusher 20 in the grinding tank 12, or it may be transported from the deactivation tank 11 to the grinding tank 12 by a known belt conveyor (not shown) and put in.

[0028] [First separation step] In the first separation step described above, the negative electrode active material and negative electrode conductive additive are separated from the negative electrode layer of the pulverized battery (deactivated battery). Specifically, for example, the pulverized deactivated battery (pulverized battery pieces) B2 may be placed in another tank (first separation tank) 13 that stores solvent M (first solvent M1 or the second solvent described above), and the negative electrode active material and negative electrode conductive additive may be separated in solvent M. The means for placing the pulverized battery pieces B2 are not particularly limited, and for example, they may be transported to the first separation tank 13 by a known belt conveyor C placed in the pulverization tank 12.

[0029] The negative electrode of the battery comprises a negative electrode current collector foil and a negative electrode composite layer, the negative electrode composite layer containing a negative electrode active material, a negative electrode conductive additive, and a negative electrode binder that binds the negative electrode active material and the negative electrode conductive additive. When the negative electrode composite layer in the pulverized battery piece B2 comes into contact with solvent M, the negative electrode binder dissolves, the negative electrode active material and the negative electrode conductive additive are loosened and separated from the negative electrode composite layer.

[0030] The first separation step described above may be carried out while transporting the crushed battery pieces B2 in the first separation layer 13 toward the second separation tank 14 in which the second separation step described above is carried out. By separating the negative electrode active material and the negative electrode conductive additive while transporting the crushed battery pieces B2, the efficiency of the battery processing method can be improved.

[0031] The means for transporting the pulverized battery pieces B2 are not particularly limited. For example, a mesh belt conveyor 30 with a belt formed of a mesh member may be used. Alternatively, a container (basket) not shown may be formed from a mesh member, and the container containing the pulverized battery pieces B2 may be transported in a solvent M by a known transport means.

[0032] The mesh opening of the mesh member described above is not particularly limited as long as it prevents the crushed battery pieces B2 from passing through and allows the negative electrode active material and the negative electrode conductive additive to pass through. For example, it may be selected to match the dimensions of the crushed battery pieces B2 crushed by the crusher 20. By using a mesh belt conveyor 30 or the container described above formed from a mesh member having such an opening, the negative electrode active material and the negative electrode conductive additive separated from the negative electrode composite layer can be suspended or settled in the first separation layer 13, and the crushed battery pieces B2 from which the negative electrode active material and the negative electrode conductive additive have been separated can be transported to the second separation tank 14.

[0033] [Second separation step] In the second separation step described above, the positive electrode active material and positive electrode conductive additive are separated from the positive electrode layer of the pulverized battery. Specifically, for example, the remaining portion of the pulverized battery pieces B2 after the first separation step (first remaining portion) B3 is placed in a tank (second separation tank) 14 storing the second solvent M2, and the positive electrode active material and positive electrode conductive additive are separated in the second solvent M2. The first remaining portion B3 is the pulverized battery pieces B2 from which the negative electrode active material and negative electrode conductive additive have been removed.

[0034] The positive electrode of the battery comprises a positive electrode current collector foil and a positive electrode composite layer, the positive electrode composite layer including a positive electrode active material, a positive electrode conductive additive, and a positive electrode binder that binds the positive electrode active material and the positive electrode conductive additive together. When the positive electrode composite layer in the first remainder B3 comes into contact with the second solvent M2, the positive electrode binder dissolves, the positive electrode active material and the positive electrode conductive additive are loosened, and separated from the positive electrode composite layer into the second solvent M2.

[0035] The second separation step described above may be carried out while transporting the first remaining portion B3 in the second separation tank 14. Separating the positive electrode active material and the positive electrode conductive additive while transporting the first remaining portion B3 improves the efficiency of the battery processing method. The means for transporting the first remaining portion B3 are not particularly limited and may be the same transport means as in the first separation step described above.

[0036] The order in which the first separation step and the second separation step are performed does not matter. That is, the second separation step may be performed after the first separation step, or the first separation step may be performed after the second separation step. If the first separation step is performed with a second solvent, the first separation step and the second separation step may be performed simultaneously.

[0037] [First Recovery Process] The battery processing method may further include a first recovery step of recovering the remaining portion (second remaining portion) B4 of the crushed battery pieces B2 after the first separation step and the second separation step. The battery processing method may further include a first classification step of classifying the second remaining portion B4 recovered in the first recovery step according to material. By classifying the recovered second remaining portion B4 according to material, such as aluminum, copper, and resin, the recycling rate of the battery to be processed can be improved. The second remaining portion B4 is the crushed battery pieces B2 from which the negative electrode active material, the negative electrode conductive additive, the positive electrode active material, and the positive electrode conductive additive have been removed.

[0038] [Second Recovery Process] The battery processing method may further include a second recovery step of recovering the solvent M containing the negative electrode active material and the negative electrode conductive additive separated in the first separation step. The battery processing method may further include a third separation step of separating the solvent M recovered in the second recovery step from the negative electrode active material and the negative electrode conductive additive in the solvent M, a first washing step of washing the negative electrode active material and the negative electrode conductive additive separated in the third separation step, and a second classification step of classifying the washed negative electrode active material and the negative electrode conductive additive by material.

[0039] [Third Recovery Process] The battery processing method may further include a third recovery step for recovering the second solvent M2 containing the positive electrode active material and the positive electrode conductive additive separated in the second separation step. The battery processing method may further include a fourth separation step for separating the second solvent M2 recovered in the third recovery step from the positive electrode active material and the positive electrode conductive additive in the second solvent M2, a second washing step for washing the positive electrode active material and the positive electrode conductive additive separated in the fourth separation step, and a third classification step for classifying the washed positive electrode active material and the positive electrode conductive additive by material.

[0040] The second and third classification steps described above are not particularly limited, and may be classified by specific gravity separation, such as by heavy liquid separation. Examples of solutions used when classifying by heavy liquid separation include aqueous ethyl acetate and sodium polytungstate. According to the heavy liquid separation method, materials with a relatively low specific gravity, such as acetylene black, tend to float in the solution, while materials with a relatively high specific gravity, such as copper, tend to precipitate. Therefore, the positive electrode active material, positive electrode conductive additive, negative electrode active material, and negative electrode conductive additive can be easily classified by material. The second and third classification steps may use the same method or different methods.

[0041] The inactivation step and the grinding step are preferably carried out in the first solvent M1. For this reason, as shown in Figure 2, the inactivation tank and the grinding tank may be treated as a single tank (first tank) 15, and the inactivation step and the grinding step may be carried out in this first tank 15, while the first separation step may be carried out in another tank (first separation tank) 13. The second separation step is carried out in the second separation tank 14.

[0042] The first separation step described above is preferably performed in the first solvent M1 if the negative electrode of the battery to be processed uses an aqueous binder. For this reason, as shown in Figure 3, the grinding tank and the first separation tank may be combined into a single tank (second tank) 16, and the deactivation step may be performed in the deactivation tank 13, and the grinding step and the first separation step may be performed in the second tank 16. Alternatively, as shown in Figure 4, the deactivation tank, the grinding tank, and the first separation tank may be combined into a single tank (third tank) 17, and the deactivation step, the grinding step and the first separation step may be performed in this third tank 17. The second separation step is performed in the second separation tank 14.

[0043] The first and second separation steps described above are preferably carried out in a second solvent M2 if the negative and positive electrodes of the battery to be processed use a PVDF binder. For this reason, as shown in Figure 5, the deactivation tank and the grinding tank may be made into one tank (fourth tank) 18, and the first separation tank and the second separation tank may be made into another tank (fifth tank) 19, with the deactivation step and the grinding step being carried out in the fourth tank 18, and the first and second separation steps being carried out in the fifth tank 19. In this case, the first and second separation steps proceed almost simultaneously. In this case, the second solvent M2 containing the negative electrode active material, the negative electrode conductive additive, the positive electrode active material, and the positive electrode conductive additive is recovered, and after recovery, the second solvent M2 is separated from the negative electrode active material, the negative electrode conductive additive, the positive electrode active material, and the positive electrode conductive additive.

[0044] <Other Embodiments> The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is not limited to the configurations of the embodiments described above, but is indicated by the claims, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Industrial applicability]

[0045] The battery processing method described herein allows for easy and safe processing of batteries, and is therefore suitable for recycling the components (materials) that make up batteries. [Explanation of Symbols]

[0046] 11 Deactivation tank 12 Grinding chamber 13 1st separation tank 14 Second separation tank 15 First Tank 16 Second tank 17 Third Tank 18. The fourth tank 19. The fifth tank 20 Crusher 30 Mesh Belt Conveyor B1 Deactivated battery B2 Crushed battery fragments B3 Remaining portion of the first B4 Second remaining portion C Belt Conveyor M solvent M1 First solvent M2 Second solvent

Claims

1. The process of deactivating the battery, The process of crushing the deactivated batteries mentioned above, A first separation step involves separating the negative electrode active material and the negative electrode conductive additive from the negative electrode layer of the crushed battery, A second separation step involves separating the positive electrode active material and positive electrode conductive additive from the positive electrode layer of the crushed battery. Equipped with, A battery processing method comprising the above-mentioned deactivation step, the above-mentioned pulverization step, the above-mentioned first separation step, and the above-mentioned second separation step, performed in a solvent.

2. The above deactivation step, the above grinding step, and the above first separation step are carried out in the first solvent. The battery processing method according to claim 1, wherein the above second separation step is performed in a second solvent.

3. The above deactivation process is carried out in one tank. The above crushing process is carried out in another tank. The battery processing method according to claim 2, wherein the above-mentioned first separation step is further carried out in another tank.

4. The above deactivation process and the above grinding process are carried out in a single tank. The battery processing method according to claim 2, wherein the above-mentioned first separation step is performed in another tank.

5. The battery processing method according to claim 2, wherein the above-mentioned deactivation step, the above-mentioned crushing step, and the above-mentioned first separation step are performed in a single tank.

6. The above deactivation step and the above grinding step are carried out with the first solvent. The battery processing method according to claim 1, wherein the first separation step and the second separation step are performed with a second solvent.

7. The first solvent mentioned above is water or saline solution. The battery processing method according to any one of claims 2 to 6, wherein the second solvent is NMP.

Images