Black Mass Processing

Abstract

To provide a method for purifying black mass of a battery and the use of a basic mixture for the purification of black mass.SOLUTION: A method 100 for purifying battery black mass includes step 101 of providing a treated cathode or anode black mass, and step 102 of contacting the treated black mass with a basic mixture, wherein the basic mixture includes at least one alcohol and at least one alcoholate.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for the purification of black mass (black lumps) and to the use of a basic mixture for the purification of black mass.

Background Art

[0002] As part of the sustainable use of raw materials, the importance of recycling is increasing. Conventional (thermal) mechanical recycling processes often lead to excessive contamination. For example, in the direct recycling of NMC (nickel-manganese-cobalt mixed oxide) cathode products in battery cell manufacturing, too much aluminum is rejected. Combinations of different processes (thermal, wet and dry mechanical) generally result in insufficient quality (purity of recyclable materials, excessive aluminum content).

[0003] In the EoL (end-of-life) recycling of batteries, there is a solvent extraction process for extracting individual metals as valuable materials.

[0004] US9825341B2 discloses the use of solvents in the treatment of battery materials.

[0005] WO2022 / 133585A1 discloses a method for recovering metals from black mass using formic acid and hydrogen peroxide.

[0006] EP3806229A1 discloses a recycling method for lithium-ion batteries using a polar solvent.

[0007] CN115347266A discloses a recycling process for lithium-ion batteries using wet grinding.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

[0009] The object of the present invention is to provide a black trout purification process and the use of a basic mixture for the purification of black trout that overcome the above-mentioned drawbacks at least partially.

[0010] This problem is solved by the method according to claim 1 and the method of use according to claim 8.

[0011] Further advantageous embodiments of the present invention are described by the following description relating to the subclaims and preferred embodiments of the present invention.

[0012] The method according to the present invention for purifying black mass from batteries includes the following steps: - A step of providing processed black mass, -The treated black mass is brought into contact with a basic mixture, thereby the basic mixture containing at least one alcohol and at least one alcoholate.

[0013] The black mass of a battery is an electrochemically active layer containing various metals such as lithium, manganese, copper, nickel, and cobalt. In the case of the cathode, the black mass is aluminum foil coated with layers of NMC (nickel-manganese-cobalt mixed oxide), binders, and conductive additives. NMC can be replaced with other active materials such as iron phosphate, nickel-cobalt-aluminum oxide, or sulfur compounds. Lithium can also be used as an additional cation. In the case of the anode, the black mass is primarily graphite with binders and conductive additives. Silicon, graphene, and lithium titanium dioxide can also be included in the black mass. Generally, most active materials are metal-doped.

[0014] In this case, it can be a cathode black mass or an anode black mass. In another embodiment, it can be a mixture of cathode black mass and anode black mass.

[0015] Black mass can originate from scrap flows, i.e., flows of recyclable materials, and these flows can be targeted for processing. Separating material flows beforehand is advantageous for any processing process. For example, it is possible to specifically adapt the process to anode foils, such as copper foil, and their residues can be specifically avoided and removed by (thermal)mechanical treatment, thereby significantly reducing contaminated black mass. The use of relatively inert active materials and aqueous systems makes it possible to selectively remove impurities such as copper from the anode side, and depending on the purity, it may even be unnecessary to separate aluminum.

[0016] The method according to the present invention includes the step of providing processed black mass, preferably high-purity black mass, by using, for example, an unmixed input stream (e.g., a material stream from manufacturing rejects or sorting pre-treatment can be used). High purity is understood to mean, for example, that the impurities in the black mass are at most 2000 ppm, preferably at most 500 ppm, and more preferably at most 20 ppm. The processing can include a variety of mechanical and / or chemical treatments. In one embodiment, the method can include mechanical crushing of manufacturing rejects / scrap into black mass. Mechanical crushing can include shredding, cutting, grinding, electro-hydraulic crushing, de-aggregation or other crushing steps.

[0017] Chemical treatment includes treatment with appropriate chemicals such as organic acids, inorganic acids, and bases.

[0018] In addition to, or as an alternative to, mechanical or chemical treatment, heat treatment may also be considered.

[0019] Mechanically and / or chemically and / or thermally treated black mass can also be split into fractions of different particle sizes. In addition or alternatively, individual particles can also be separated.

[0020] Preferably, the black mass is processed into a powder. For example, the processed black mass can be a pure powdered cathode material.

[0021] In a further step of this method, the treated black mass is brought into contact with a basic mixture, which contains at least one alcohol and at least one alcoholate.

[0022] In one embodiment, at least one alcohol is an alcohol selected from C3-C8 alcohols. Preferably, at least one alcohol is an alcohol selected from C3-C6 alcohols. At least one alcohol can be selected from the group consisting of propanol, isopropanol, n-butanol, pentanol, and hexanol isomers.

[0023] At least one alcohol is preferably n-butanol.

[0024] At least one alcohol can also be a mixture of at least two alcohols. Also, at least one alcohol may be a mixture of at least one alcohol (e.g., C3-C8 alcohol) and water.

[0025] Furthermore, the basic mixture contains at least one alcoholate. In one embodiment, the alcoholate is an alkali metal alcoholate or a transition metal alcoholate. The alcoholate may also be an alkaline earth metal alcoholate.

[0026] The alkali alcoholate can be selected from the group consisting of Li-alcoholate, Na-alcoholate, and potassium-alcoholate. In a preferred embodiment, the alkali metal alcoholate is Li-alcoholate.

[0027] The transition metal alcoholate can be selected from the group consisting of Fe-alcoholate, Ni-alcoholate, and Cr-alcoholate.

[0028] At least one alkali alcoholate or transition metal alcoholate may be a mixture of at least two alcoholates.

[0029] Preferably, the alcoholate corresponds to at least one alcohol used. For example, the alcohol may be butanol, and the alcoholate may be butanolate.

[0030] Preferably, the basic mixture comprises isopropanol and Li-isopropanolate. Alternatively, the basic mixture comprises tert-butanol and Li-tert-butanolate.

[0031] At least one alcohol and at least one alcoholate can be present in a specific ratio. The ratio of at least one alcohol and at least one alcoholate may be in the range of 99:1 to 8:2, preferably in the range of 99:1 to 9:1, and more preferably in the range of 98:2 to 95:5.

[0032] In one embodiment, the basic mixture has a pH value in the range of 7.5 or higher. In a preferred embodiment, the basic mixture has a pH value in the range of 8 to 14, and in a more preferred embodiment, the basic mixture has a pH value in the range of 9 to 12.

[0033] base Basic mixtures may also contain other components. Basic mixtures may contain complexing agents or other auxiliary substances. For example, basic mixtures may contain complexing agents for various metals, such as aluminum complexing agents.

[0034] Processed black mass base By contacting the black mass with a basic mixture, components such as aluminum and / or aluminum oxide can be selectively separated. Aluminum can form amphoteric aluminum with the basic mixture, and as a result, it can be separated from the treated black mass. By forming amphoteric aluminum, even small amounts of aluminum can be separated, and thus the treated black mass can be purified. Particularly preferable is that the basic mixture does not attack or destroy other components of the black mass, and the particulate structure of components such as NMC (nickel-manganese-cobalt mixed oxide) is not attacked.

[0035] The separated components, such as aluminum, are sent for further processing or recycling, returning them to the material cycle.

[0036] Black mass can be dry black mass. Dry black mass from battery recycling does not contain liquid components such as electrolytes or liquid battery slurry. Rather, dry black mass consists of coated coils, crumpled material resulting from defects, individual sheets, or laminated materials, which are further separated (separation of cathode, anode, separator, and auxiliary materials) and, if necessary, removed beforehand from the housing (solid or bag). Dry black mass can originate particularly from manufacturing waste.

[0037] Alternatively, it can be wet black mass. Wet black mass from battery recycling contains liquid components such as electrolyte or liquid battery slurry. Wet black mass can come from faulty batteries, battery materials generated during the mixing and coating process, or batteries that have reached the end of their lifespan.

[0038] When using wet black mass, it can be wet-ground together with a basic mixture and then used in this method.

[0039] This method may further include a step of mechanically separating the black mass from the basic mixture. The mechanical separation may include filtration, sieving, sedimentation, centrifugation, or other mechanical separation steps. The separation can be carried out using, for example, sieves, decanters, filters, etc.

[0040] The separated black mass can be further purified. Further purification can be carried out by washing with a suitable solvent, washing with a basic mixture, or repeated washing. Next, the washed black mass can be liberated from the solvent or basic mixture. This can be done by drying at high temperature, blowing in dry air or an inert gas, or washing with a solvent favorable for further processing of the black mass (e.g., NMP). Solvent recovery can also be included in this process.

[0041] A further object of the present invention is the use of a basic mixture comprising at least one alcohol and at least one alcoholate. The black mass may be dried black mass as described herein, or it may be wet black mass as described herein.

[0042] The basic mixture, at least one alcohol, and at least one alkoxide may be the basic mixture, alcohol, and alkoxide described herein, respectively. Preferably, the basic mixture comprises at least one Li-alkoxide. The Li-alkoxide may be the Li-alkoxide described herein.

[0043] Next, embodiments of the present invention will be described with reference to the accompanying drawings as examples: [Brief explanation of the drawing]

[0044] [Figure 1] Figure 1 shows a schematic diagram of the method according to the present invention. [Figure 2] Figure 2 shows a schematic diagram of the method according to the present invention. [Figure 3] Figure 3 shows a schematic diagram of the method according to the present invention. [Modes for carrying out the invention]

[0045] An example of an embodiment of method 100 according to the present invention is shown in Figure 1. The method for purifying black mass of battery 100 includes step 101, in which treated black mass is provided. The treated black mass is then brought into contact with a basic mixture 102, the basic mixture comprising at least one alcohol and at least one alcoholate.

[0046] Figure 2 shows further embodiments of a method for purifying black mass from battery 200. Firstly, a conventional black mass extraction 203 can be performed. The conventional black mass extraction 203 may include dry mechanical stripping. If necessary, heat treatment and / or dry separation may also be performed during the conventional black mass extraction 203. The conventional black mass extraction 203 can be used to recover the processed black mass 201 and residue 210 such as aluminum foil. The residue 210 such as aluminum foil can be sent to aluminum recycling 211. Next, the processed black mass 201 can be contacted with a basic mixture 202 to form a slurry. The basic mixture contains at least one alcohol and at least one alkoxide (e.g., Li-alkoxide). This allows for the selective dissolution of aluminum still present in the black mass. Subsequently, mechanical separation 204 can be performed by removing the contaminated solvent, for example by filtration, decantation, etc. The separated solid can be washed by washing 205 and contacted again with the basic mixture 202. The solid 206 obtained from separation 204 is the processed black mass. The liquid 207 obtained from separation 204 is at least one alcohol, at least one alkoxide, and at least one aluminum ion or at least one aluminum complex. The at least one alcohol, at least one alkoxide, and aluminum ions or aluminum complex can be fed to process 208. In this process, the at least one alcohol, at least one alkoxide, and / or aluminum ions or aluminum complex can be reprocessed and reused. Residual water 209 can then be removed, and thus, for example, solvents that cannot be reused can be removed. The residual water 209 can be removed by drying and / or washing with a suitable solvent (e.g., NMP).

[0047] Figure 3 shows a further embodiment of a method for purifying the black mass of a battery 300. First, conventional pre-shredding of the battery material 312 can be performed. Conventional pre-shredding can be carried out by a shredder or granulator. Next, the shredded material 313 can be fed to a wet grinding step 314. Here, the shredded material 313 is wet-ground using at least one alcohol and at least one alkoxide (e.g., Li-alkoxide). This results in delamination and dissolution of the aluminum present. In a further step, multi-stage mechanical separation 315 of the liquid, film, black mass and present grinding medium can be performed. If necessary, the mechanically separated material can be washed 305 and fed back to the wet grinding 314. Mechanical separation 315 yields a solid 306, i.e., the processed black mass, a liquid 307, e.g., at least one alcohol, at least one aluminum alkoxide or aluminum complex, and aluminum foil 316. The aluminum foil can be fed to an aluminum recycling 311. At least one alcohol, at least one alkoxide, and aluminum can be supplied to process 308. In this method, at least one alcohol, at least one alkoxide, and / or aluminum can be recycled and reused. Residual moisture can then be removed 309, and thus, for example, unreusable solvents can be removed. Residual moisture 309 can be removed by drying and / or washing with a suitable solvent (e.g., NMP).

[0048] Example: Preparation of cathode black mass after a simple mechanical process for black mass extraction. 1. Crush the cathode foil. 2. If necessary, thermally decompose at 500°C with a residence time of 1 hour. 3. Hammer mill (sieve width 5mm) 4. Sieving using a vibrating sieve (125 μm) 5. Add the fine fraction (approximately 100g) to a stirring container containing 1000g of isopropanol and 50g of Li-2-propanolic acid dissolved in alcohol. 6. Mixing for 45 minutes to dissolve aluminum impurities. 7. Filtration (filter) 5μm 8. Solid: Add 1000g of isopropanol and 10g of Li-2-propanolate dissolved in alcohol to a container and stir. 9. Filtration (filter) 5μm Dry the solids in a drying oven at 10.85°C. 11. IPC-based contamination control

[0049] List of reference numbers 100, 200, 300 Methods for Purifying Black Mass 101,201 processed black mass offered 102,202 Treated black mass is brought into contact with a basic mixture. 203 Conventional Black Mass Extraction 204 Mechanical separation 205,305 washes 206,306 solid 207,307 liquid 208,308 processes 209,309 Removal of residual moisture 210 Residue 211,311 Aluminum recycling 312 Pre-shredding of battery materials 313 Shredded material 314 Wet grinding 315 Mechanical separation 316 Aluminum foil This invention includes the following items. [Item 1] A method for refining the black mass of batteries: - A step of providing a processed cathode and anode black mass, - The processed black mass is brought into contact with a basic mixture, wherein the basic mixture comprises at least one alcohol and at least one alcoholate. The method comprising the above. [Item 2] The above at least one alcohol is C 3 -C 8 The method described in item 1, which is an alcohol. [Item 3] The method according to item 1 or 2, wherein the at least one alkoxide is an alkali metal alkoxide or a transition metal alkoxide. [Item 4] The method according to at least one of items 1 to 3, wherein the at least one alcohol is a Li-alcolate. [Item 5] The method according to at least one of items 1 to 4, wherein the basic mixture has a pH in the range of 7.5 or higher. [Item 6] The method according to at least one of items 1 to 5, wherein the ratio of the at least one alcohol to the at least one alcoholate is in the range of 99:1 to 8:2. [Item 7] The method according to at least one of items 1 to 6, wherein the black trout is dried black trout. [Item 8] The method according to at least one of items 1 to 6, wherein the treated black mass and the basic mixture are wet-ground together. [Item 9] A method according to at least one of items 1 to 8, further comprising the step of mechanically separating the black mass from the basic mixture. [Item 10] Use of a basic mixture containing at least one alcohol and at least one alcoholate for the purification of black mass. [Item 11] The use according to item 10, wherein the basic mixture comprises at least one Li-alkoxide.

Claims

1. A method for refining the black mass of batteries: - A step of providing a processed cathode and anode black mass, - The processed black mass is brought into contact with a basic mixture, wherein the basic mixture comprises at least one alcohol and at least one alcoholate. The at least one alcohol is a C3-C8 alcohol, The ratio of the at least one alcohol to the at least one alcoholate is in the range of 99:1 to 8:

2. The method comprising the above.

2. The method according to claim 1, wherein the at least one alcohol is isopropanol.

3. The method according to claim 1 or 2, wherein the at least one alkoxide is an alkali metal alkoxide or a transition metal alkoxide.

4. The method according to claim 1 or 2, wherein the at least one alkoxide is a Li-alkoxide.

5. The method according to claim 1 or 2, wherein the basic mixture has a pH in the range of 7.5 or higher.

6. The method according to claim 1 or 2, wherein the ratio of the at least one alcohol to the at least one alcoholate is in the range of 99:1 to 9:

1.

7. The method according to claim 1 or 2, wherein the black trout is dried black trout.

8. The method according to claim 1 or 2, wherein the treated black mass and the basic mixture are wet-ground together.

9. The method according to claim 1 or 2, further comprising the step of mechanically separating the black mass from the basic mixture.

10. A basic mixture comprising at least one alcohol and at least one alcoholate for the purpose of purifying black mass by contacting the basic mixture, The at least one of the alcohols is a C3-C8 alcohol, The use wherein the ratio of the at least one alcohol to the at least one alcoholate is in the range of 99:1 to 8:

2.

11. The use according to claim 10, wherein the basic mixture comprises at least one Li-alkoxide.

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