Method for producing recycled material

Abstract

To provide a method for effectively utilizing carbon contained in a battery material.SOLUTION: The method for producing a recycled material includes the following (a) and (b). (a) preparing a battery material; (b) Carbon contained in the battery material is reacted with sulfur to produce carbon disulfide.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a method for producing recycled materials. [Background technology]

[0002] JP 2022-147471 A discloses a method for recovering metals from electrode plates. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2022-147471 Summary of the Invention [Problem to be solved by the invention]

[0004] There is a need to recover various materials from discarded batteries and other waste materials for recycling. Various methods for recovering and reusing metals have been proposed. However, there is still room for improvement in recovering and reusing carbon.

[0005] An object of the present disclosure is to provide a method for effectively utilizing carbon contained in battery materials. [Means for solving the problem]

[0006] 1. The method for producing recycled materials includes the following (a) and (b): (a) Prepare the battery materials. (b) Carbon disulfide is produced by reacting the carbon contained in the battery material with sulfur.

[0007] In the present disclosure, carbon can be easily recovered from battery materials and effectively utilized. That is, in the present disclosure, carbon disulfide (CS2) is produced from battery materials containing carbon. CS2 is a recycled material. CS2 can be used as a raw material for various chemical products. For example, viscose rayon, cellophane, carbon tetrachloride, etc. can be produced using CS2 as a raw material.

[0008] 2. The method for producing recycled materials described in "1" above may include, for example, the following configuration: The battery material includes at least one selected from the group consisting of a positive electrode plate, a negative electrode plate, a bipolar electrode plate, a positive electrode composite, a negative electrode composite, black mass, and sludge.

[0009] Any battery material may be used as long as it contains carbon, such as a conductive material in an electrode mixture, a binder, or a carbon-based negative electrode active material.

[0010] 3. The method for producing a recycled material according to the above "1" or "2" may include, for example, the following configuration: (a) above includes the following (a1). (a1) The battery material is crushed to form a powder.

[0011] By crushing the battery material, it is expected that, for example, the contact efficiency between carbon and sulfur will improve.

[0012] 4. The method for producing a recycled material according to any one of the above items "1" to "3" may include, for example, the following configuration: (a) above includes the following (a2). (a2) The battery material is heated to carbonize the organic matter contained in the battery material.

[0013] It is expected that the yield of CS2 will be improved by carbonizing organic materials (e.g., binders) in advance.

[0014] 5. The method for producing a recycled material according to any one of the above items "1" to "4" may include, for example, the following configuration: (b) above includes contacting sulfur vapor with the battery material.

[0015] The use of sulfur vapor is expected to improve, for example, the efficiency of contact between carbon and sulfur.

[0016] Hereinafter, one embodiment of the present disclosure (hereinafter, may be abbreviated as "the present embodiment") will be described. However, this embodiment does not limit the technical scope of the present disclosure. This embodiment is illustrative in all respects. This embodiment is non-restrictive. The technical scope of the present disclosure encompasses all modifications within the meaning and scope equivalent to the claims. For example, it is also intended from the beginning that any configuration may be extracted from this embodiment and arbitrarily combined. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a schematic flowchart showing a method for producing recycled materials in this embodiment. [Figure 2] FIG. 2 is a schematic cross-sectional view showing an example of a positive electrode plate in the present embodiment. [Figure 3] FIG. 2 is a schematic cross-sectional view showing an example of a negative electrode plate in the present embodiment. [Figure 4] FIG. 2 is a schematic cross-sectional view showing an example of a bipolar electrode plate in the present embodiment. [Figure 5] FIG. 2 is a conceptual diagram illustrating an example of a manufacturing apparatus according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0018] -Terms and phrases- The terms "comprise," "include," "have," and variations thereof are open-ended. An open-ended configuration may or may not include additional elements in addition to the required elements.

[0019] Unless otherwise specified, the order of execution of multiple steps, actions, operations, etc. included in various methods is not limited to the order described. For example, multiple steps may proceed simultaneously. For example, multiple steps may occur one after the other.

[0020] "Battery material" refers to any material, member, or part contained in a battery. The battery material may be a single substance or a mixture (e.g., composite material, etc.). The battery material may be, for example, a composite (e.g., electrode plate, etc.), a molded body, etc.

[0021] "Black mass" refers to a concentrate obtained by heat treating (roasting) a battery, crushing the roasted material, and sorting the crushed material. Black mass contains metals such as nickel, cobalt, and manganese. Metals such as nickel may be components derived from the positive electrode active material.

[0022] "Sludge" refers to the residue remaining after valuable metals such as nickel, cobalt, and manganese are extracted from black mass. Conventionally, sludge has been discarded. In this embodiment, sludge can be effectively utilized as a target for carbon recovery.

[0023] -Method of manufacturing recycled materials- FIG. 1 is a schematic flowchart showing a method for producing a recycled material in this embodiment. Hereinafter, the "method for producing a recycled material in this embodiment" may be abbreviated as "this method." This method includes "(a) preparation" and "(b) sulfurization." In this method, CS2 is produced. CS2 is a recycled material. This method may further include "(c) regeneration," etc. In "(c) regeneration," for example, another recycled material can be produced using CS2 as a raw material.

[0024] (a) Preparation The method includes preparing a battery material. The battery material may be any material as long as it contains carbon. The battery material may contain, for example, at least one selected from the group consisting of a positive electrode plate, a negative electrode plate, a bipolar electrode plate, a positive electrode composite, a negative electrode composite, black mass, and sludge. The battery material may be prepared by any method. For example, various battery materials may be recovered by dismantling used batteries, defective batteries, etc. For example, carbon-free battery materials may be separated from carbon-containing battery materials. Other regeneration processes may be applied to the carbon-free battery materials. For example, black mass, sludge, etc. may be formed by subjecting used batteries, defective batteries, etc. to various treatments such as roasting.

[0025] FIG. 2 is a schematic cross-sectional view showing an example of a positive electrode plate in this embodiment. The positive electrode plate 10 includes a positive electrode current collector foil 11 and a positive electrode composite material 12. The positive electrode current collector foil 11 may include, for example, aluminum. The positive electrode composite material 12 is attached to the positive electrode current collector foil 11. The positive electrode composite material 12 includes, for example, a positive electrode active material, a conductive material, a binder, and the like. The positive electrode active material may include, for example, a lithium-nickel composite oxide, an olivine-type phosphate compound, and the like. The conductive material may include, for example, graphite, carbon black, carbon fiber, carbon nanotubes, graphene flakes, and the like. The binder may include, for example, polyvinylidene fluoride, and the like.

[0026] 3 is a schematic cross-sectional view showing an example of a negative electrode plate in this embodiment. The negative electrode plate 20 includes a negative electrode current collector foil 21 and a negative electrode composite material 22. The negative electrode current collector foil 21 may contain, for example, copper or the like. The negative electrode composite material 22 is attached to the negative electrode current collector foil 21. The negative electrode composite material 22 includes, for example, a negative electrode active material, a conductive material, a binder, and the like. The negative electrode active material may include, for example, graphite, soft carbon, hard carbon, silicon, silicon oxide, a silicon-carbon composite material (Si / C material), a lithium-titanium composite oxide, and the like. The conductive material is the same as that of the positive electrode composite material 12. The binder may include, for example, carboxymethyl cellulose, styrene-butadiene rubber, and the like.

[0027] FIG. 4 is a schematic cross-sectional view showing an example of a bipolar electrode plate according to this embodiment. The bipolar electrode plate 30 includes a positive electrode composite 12, a positive electrode current collector foil 11, a negative electrode current collector foil 21, and a negative electrode composite 22. For example, an adhesive (not shown) may bond the positive electrode current collector foil 11 and the negative electrode current collector foil 21. The positive electrode composite 12 and the negative electrode composite 22 are on opposite sides of each other. The regeneration process for the bipolar electrode plate 30 typically begins with the separation of the positive electrode composite 12 and the negative electrode composite 22. During the separation, contamination from the negative electrode composite 22 to the positive electrode composite 12 may occur. Therefore, for example, when a carbon-based negative electrode active material (such as graphite) is used, a large amount of carbon tends to be discarded. This method is particularly effective for the bipolar electrode plate 30.

[0028] In the positive electrode plate 10, the negative electrode plate 20, and the bipolar electrode plate 30, the carbon to be recovered is mainly a conductive material (carbon black, etc.), a binder (organic polymer), and a carbon-based negative electrode active material (graphite, soft carbon, hard carbon, Si / C material, etc.). For example, a conductive material (carbon black, etc.) may be applied to the surface of the positive electrode current collector foil 11. The conductive material applied to the positive electrode current collector foil 11 may also be a target for carbon recovery.

[0029] (a1) Crushing This method may include, for example, crushing the battery material to form a powder or granular material. The battery material may be crushed using any crushing device. Crushing the battery material is expected to improve, for example, handleability. Furthermore, in the "(b) sulfurization" described below, it is expected that the contact efficiency between carbon and sulfur will be improved. For example, the positive electrode mixture 12 may be crushed after being peeled from the positive electrode current collector foil 11. For example, the positive electrode plate 10 may be crushed as is.

[0030] (a2) Carbonization The method may include carbonizing organic matter contained in the battery material by heating the battery material. For example, the crushed powder may be heated. Any heating device may be used. For example, the battery material may be heated at a temperature of 300°C or higher. Heating is expected to carbonize the organic matter (e.g., binder, etc.). Prior carbonization of the organic matter is expected to improve the yield of CS2 in the "(b) sulfurization" described below. The carbonization temperature (heating temperature) may be, for example, 450°C or higher or 600°C or higher. The carbonization temperature may be, for example, 900°C or lower, 750°C or lower, or 600°C or lower. The carbonization atmosphere may be, for example, an air atmosphere, a low-oxygen atmosphere, an oxygen-free atmosphere, etc.

[0031] (b) Sulfurization This method involves producing CS2 by reacting carbon (C) and sulfur (S) contained in the battery material. FIG. 5 is a conceptual diagram showing an example of a manufacturing apparatus according to this embodiment. The manufacturing apparatus 100 may include, for example, a heating furnace 101, a recovery pipe 102, a cooling tower 103, a recovery container 104, a gas introduction pipe 105, and the like. For example, a workpiece 50 is placed in the heating furnace 101. The workpiece 50 may be, for example, a mixture of the battery material and sulfur powder (solid). The workpiece 50 is heated in the heating furnace 101. For example, the temperature may be increased to 850 to 950°C. During the temperature increase, sulfur powder may exceed the boiling point of sulfur (444.6°C), thereby generating sulfur vapor. The sulfur vapor may penetrate into the battery material, thereby bringing the sulfur and carbon into contact. That is, this method involves bringing sulfur vapor into contact with the battery material. When the battery material is in the form of powder or granules (crushed material), the penetration of sulfur vapor is thought to proceed smoothly. CS2 can be generated by the reaction "C + 2S → CS2" proceeding in the temperature range of 850 to 950°C. Since the inside of the heating furnace 101 is an environment exceeding the boiling point of CS2 (46.5°C), CS2 can be generated in a gaseous state.

[0032] The manufacturing apparatus 100 may further include, for example, a stirring device (not shown) or the like. For example, the workpiece 50 may be stirred in the heating furnace 101. Stirring the workpiece 50 is expected to improve the contact efficiency between sulfur and carbon.

[0033] The generated CS2 (gas) can reach the cooling tower 103 through the recovery pipe 102. In the cooling tower 103, the CS2 can be cooled to a temperature below its boiling point, thereby liquefying the CS2. The CS2 (liquid) can be recovered in the recovery vessel 104.

[0034] For example, sulfur vapor may be used instead of sulfur powder (solid). For example, sulfur vapor may be sprayed onto the workpiece 50 during heating. For example, sulfur vapor may be supplied into the heating furnace 101 through the gas introduction pipe 105.

[0035] For example, the workpiece 50 may be a positive electrode plate 10, a negative electrode plate 20, a bipolar electrode plate 30, or the like. For example, sulfur vapor may be sprayed onto the positive electrode plate 10 (an integrated body of the positive electrode composite 12 and the positive electrode current collector foil 11) in a heating furnace 101. In this manner, CS2 is generated, and the positive electrode composite 12 loses its adhesive force, which may cause it to separate from the positive electrode current collector foil 11.

[0036] The treated residue is a reduced carbon battery material that can be subjected to other regeneration processes (e.g., metal extraction, etc.).

[0037] (c) Regeneration CS2 is a recycled material. Various materials can be manufactured using CS2 as a raw material. For example, viscose rayon, cellophane, carbon tetrachloride, etc. can be manufactured using CS2 as a raw material.

[0038] CS2 may be used as a solvent, for example, for phosphorus, sulfur, selenium, bromine, iodine, lipids, resins, rubbers, etc.

[0039] For example, lithium sulfide (Li2S) may be produced using CS2 as a raw material. Lithium sulfide can be used as a raw material for sulfide solid electrolytes (e.g., Li2S-P2S5, etc.). Sulfide solid electrolytes are key materials for all-solid-state batteries. For example, lithium sulfide may be synthesized by the reaction "4LiH + CS2 → 2Li2S + C + 2H2". Alternatively, lithium sulfide may be synthesized by the reaction "4Li + CS2 → 2Li2S + C".

[0040] For example, carbonyl sulfide (COS) may be produced using CS2 as a raw material. Carbonyl sulfide may be used, for example, as an etching gas in the semiconductor manufacturing process. For example, carbonyl sulfide may be synthesized by the reaction "CO2 + CS2 → 2COS." As shown in the reaction formula, carbon dioxide may be consumed in the carbonyl sulfide production process, which contributes to carbon neutrality.

[0041] Furthermore, carbon monoxide may be produced, for example, by the catalytic decomposition reaction of carbonyl sulfide (COS → CO + S). Carbon monoxide can be used as a raw material for various fuels and the chemical industry. Furthermore, the sulfur produced together with carbon monoxide can be reused for carbon recovery. [Explanation of symbols]

[0042] 10 positive electrode plate, 11 positive electrode current collector foil, 12 positive electrode composite, 20 negative electrode plate, 21 negative electrode current collector foil, 22 negative electrode composite, 30 bipolar electrode plate, 50 workpiece, 100 manufacturing equipment, 101 heating furnace, 102 recovery pipe, 103 cooling tower, 104 recovery container, 105 gas introduction pipe.

Claims

1. (a) providing battery materials; and (b) reacting carbon contained in the battery material with sulfur to produce carbon disulfide; Including, How recycled materials are produced.

2. The battery material includes at least one selected from the group consisting of a positive electrode plate, a negative electrode plate, a bipolar electrode plate, a positive electrode mixture, a negative electrode mixture, black mass, and sludge; A method for producing the recycled material according to claim 1.

3. The (a) is (a1) crushing the battery material to form a powder; Including, A method for producing the recycled material according to claim 1.

4. The (a) is (a2) carbonizing the organic matter contained in the battery material by heating the battery material; Including, A method for producing the recycled material according to claim 1.

5. (b) includes contacting the battery material with sulfur vapor; A method for producing the recycled material according to any one of claims 1 to 4.

Images