Method for recycling lithium and cobalt from waste lithium battery cathode materials using a deep eutectic solvent

Abstract

The present invention relates to a method for recovering lithium and cobalt from waste lithium battery cathode materials using a deep eutectic solvent, belonging to the technical field of battery recycling. In the present invention, waste particles are stirred in a deep eutectic solvent solution and stirred at a constant temperature at an appropriate temperature to promote the leaching of lithium and cobalt. Steps such as drying, adding urea, grinding, and roasting help to further extract higher-purity lithium and cobalt solid products from the leaching solution. The present invention modifies the dispersant, and the multi-layer structure formed by components such as graphene oxide, nano-silica, and chitosan in the dispersant on the surface of the cathode material particles can comprehensively play multiple roles such as dispersion, filling, adhesion, and protection, thereby significantly improving the dispersibility and stability of the cathode material in the deep eutectic solvent solution, promoting the leaching of lithium and cobalt, and improving the purity of the final product.

Description

Technical Field

[0001] The invention belongs to the technical field of battery recycling and relates to a method for recycling lithium and cobalt in positive electrode materials of waste lithium batteries using a low eutectic solvent. Background Art

[0002] As an efficient and environmentally friendly energy storage device, lithium batteries have been widely used in electric vehicles, mobile devices and other fields. However, the random discarding of used lithium batteries not only wastes a large amount of precious resources such as lithium and cobalt, but also may cause serious pollution to the environment. Therefore, the development of an efficient and environmentally friendly waste lithium battery recycling technology is of great significance for achieving resource recycling and environmental protection.

[0003] Traditional methods for recycling waste lithium batteries mainly include pyrometallurgy and hydrometallurgy. Although pyrometallurgy can recover some metal elements, it has high energy consumption, high pollution, and low recovery efficiency. Although the hydrometallurgical method is relatively environmentally friendly, it has problems such as complex process flow, high recovery cost, and low product purity. Therefore, it is urgent to develop a new, efficient, and environmentally friendly waste lithium battery recycling technology.

[0004] In recent years, deep eutectic solvents (DESs), as a new type of green solvent, have shown great application potential in the field of waste lithium battery recycling due to their high thermal stability, non-flammability, designability, and ability to dissolve organic and inorganic compounds. Deep eutectic solvents are usually mixed with two or more compounds in a certain proportion. Their melting point is lower than the melting point of any pure component and they have good solubility and stability. By selecting suitable hydrogen bond acceptors and hydrogen bond donors, deep eutectic solvents with specific properties can be prepared for the extraction and recovery of valuable metals in the positive electrode materials of waste lithium batteries. Summary of the invention

[0005] The object of the present invention is to provide a method for recovering lithium and cobalt from waste lithium battery positive electrode materials using a low eutectic solvent, which has the characteristics of high recovery rate.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A method for recovering lithium and cobalt from waste lithium battery positive electrode materials by using a low eutectic solvent, wherein the low eutectic solvent comprises a hydrogen bond donor and a hydrogen bond acceptor, wherein the molar ratio of the two is 1:(1-3).

[0008] The specific steps of the recovery method are as follows:

[0009] S1: mixing a hydrogen bond donor and a hydrogen bond acceptor in a molar ratio, stirring at a speed of 150 to 200 r / min, heating to 60 to 70° C. while stirring, and stirring for 1 to 2 h to obtain the low eutectic solvent;

[0010] S2: Cooling the low eutectic solvent to room temperature, mixing it with deionized water at a volume ratio of 1:(5-10) at a rotation speed of 150 r / min to obtain a low eutectic solvent solution;

[0011] S3: The recycled waste lithium battery is immersed in liquid nitrogen and cooled for 2 hours at a cooling temperature of -196°C. After freezing, the battery waste is perforated first, and then the cooled waste is immersed in an electrolyte for 3 to 5 hours. The electrolyte is a 1 mol / L oxalic acid solution, and then allowed to stand and dry. After disassembly, the positive electrode material is obtained;

[0012] S4: grinding the positive electrode material in a ball mill at a speed of 500 r / min for 4 to 5 hours to obtain particles with a particle size of 500 mesh, adding 0.3 wt% of a dispersant, and mixing the two evenly to obtain waste particles;

[0013] S5: dispersing the waste particles into a low eutectic solvent solution, stirring at a speed of 150 r / min, heating to 80-100° C. while stirring, continuing stirring for 2-3 hours after constant temperature, slowly cooling to room temperature after stirring, centrifugation, filtering, and obtaining a clear solution containing lithium and cobalt on the upper layer;

[0014] S6: Dry the lithium and cobalt-containing clear liquid at 80°C for 6 hours to obtain a solid crude product containing lithium and cobalt, add 1 wt% of urea to the solid crude product of lithium and cobalt, grind it in a ball mill at 400 r / min for 1 hour, transfer it to a muffle furnace preheated to 250-300°C and burn it for 2-3 minutes, then heat it to 500°C and roast it for 4 hours. After roasting, cool and grind it to obtain a solid product of lithium and cobalt, and complete the recovery.

[0015] Furthermore, the hydrogen bond donor is one or more of citric acid, glycerol, and glucose.

[0016] Furthermore, the hydrogen bond acceptor is one of choline chloride and proline.

[0017] Furthermore, the solid-liquid mass ratio of the waste lithium batteries and the electrolyte in S3 is 1:5.

[0018] Furthermore, the dispersant in S4 is modified nano-silica, and the modification method is as follows: dissolving graphene oxide in deionized water to obtain a graphene oxide solution with a mass fraction of 50%, adding nano-silica to the graphene oxide solution with a solid-liquid mass ratio of 1:1, and then adding 2wt% chitosan. After ultrasonication for 1 hour, drying at 110°C for 8 hours, and then calcining at 250°C for 2 hours, grinding and crushing to a particle size of 500 mesh, to obtain the dispersant.

[0019] Furthermore, the solid-liquid mass ratio of the waste particles to the low eutectic solvent solution in S5 is 1:(1-3).

[0020] Furthermore, the rate of slowly cooling to room temperature in S5 is 2°C / min.

[0021] Furthermore, the parameters of the centrifugal separation in S5 are a rotation speed of 12000 rpm and a centrifugal time of 8 to 12 minutes.

[0022] Furthermore, the heating rate of the muffle furnace in S6 is 5°C / min.

[0023] Furthermore, the particle size of the solid product of lithium and cobalt obtained by grinding in S6 is 200 mesh.

[0024] The recovery method of the invention can realize efficient recovery of lithium and cobalt, has a high recovery rate, and the obtained solid product has high purity.

[0025] Compared with traditional pyrometallurgical and hydrometallurgical methods, the low eutectic solvent used in the recovery method of the present invention is more environmentally friendly and biodegradable, and no harmful waste gas and wastewater are generated during the entire recovery process, which is environmentally friendly. At the same time, the method has low energy consumption and can save a lot of energy. In addition, the present invention simplifies the recovery process of waste lithium batteries, reduces the recovery cost, and improves the recovery efficiency.

[0026] After being cooled in liquid nitrogen, the waste lithium batteries are perforated and immersed in the electrolyte, which is conducive to the separation of positive electrode materials and the leaching of lithium and cobalt metals. The positive electrode material can be refined to an appropriate particle size by grinding it in a ball mill to improve the leaching efficiency. Stirring the waste particles in a low eutectic solvent solution and stirring at a constant temperature at an appropriate temperature can promote the leaching of lithium and cobalt. Steps such as drying, adding urea, grinding and roasting help to extract high-purity lithium and cobalt solid products from the leachate.

[0027] Urea is added to the solid crude products of lithium and cobalt, and after grinding in a ball mill, burned and roasted, urea not only acts as a reducing agent to help reduce metal ions, but also forms complexes with metal ions, thereby improving the leaching rate and purity of the metal.

[0028] The C and N elements in urea have certain reducing properties and can undergo redox reactions with metal ions to improve the leaching rate and purity of lithium and cobalt. The N atoms in urea have lone pairs of electrons and can form complexes with metal ions. This complexation helps transfer metal ions from the solid phase to the liquid phase, further improving the leaching efficiency of lithium and cobalt. After adding urea, through steps such as grinding, combustion and roasting, urea can decompose to produce gases, which help promote the combustion and roasting process of the material, making lithium and cobalt easier to reduce and extract.

[0029] The addition of the dispersant in the present invention can significantly improve the dispersion state of the positive electrode material particles in the low eutectic solvent solution, reduce the agglomeration and aggregation between the particles, and the well-dispersed positive electrode material particles can be more fully in contact with the low eutectic solvent, thereby improving the leaching efficiency of lithium and cobalt. The use of the dispersant helps to reduce the interference of impurities in the leaching process, thereby improving the purity of the lithium and cobalt solid products finally recovered. The components such as graphene oxide, nano-silicon dioxide and chitosan in the dispersant can enhance the stability of the material and prevent unnecessary chemical reactions or structural changes in the subsequent processing process.

[0030] Graphene oxide has excellent dispersibility and can be adsorbed on the surface of cathode material particles to form a protective film to prevent agglomeration between particles. Nano-silicon dioxide particles can fill the gaps between cathode material particles to further reduce agglomeration and improve the overall stability and mechanical strength of the material. Chitosan has good adhesion and protection and can be firmly adsorbed on the surface of cathode material particles to form a protective layer to prevent the particles from being damaged or contaminated during subsequent processing.

[0031] Therefore, the multilayer structure formed by components such as graphene oxide, nano-silica and chitosan in the dispersant on the surface of the positive electrode material particles can comprehensively play multiple roles such as dispersion, filling, adhesion and protection, thereby significantly improving the dispersibility and stability of the positive electrode material in the low eutectic solvent solution, promoting the leaching of lithium and cobalt, and improving the purity of the final product.

[0032] Beneficial effects of the present invention:

[0033] The present invention stirs waste particles in a low eutectic solvent solution and stirs at a constant temperature at an appropriate temperature, thereby promoting the leaching of lithium and cobalt. Steps such as drying, adding urea, grinding and roasting are helpful to further extract lithium and cobalt solid products with higher purity from the leaching solution.

[0034] The present invention modifies the dispersant, and the multilayer structure formed by components such as graphene oxide, nano-silicon dioxide and chitosan in the dispersant on the surface of the positive electrode material particles can comprehensively play multiple roles such as dispersion, filling, adhesion and protection, thereby significantly improving the dispersibility and stability of the positive electrode material in the low eutectic solvent solution, promoting the leaching of lithium and cobalt, and improving the purity of the final product. DETAILED DESCRIPTION

[0035] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention are described in detail below in combination with the embodiments.

[0036] Example 1

[0037] A method for recovering lithium and cobalt from waste lithium battery positive electrode materials using a low eutectic solvent, wherein the low eutectic solvent comprises citric acid and choline chloride in a molar ratio of 1:2.

[0038] The specific steps of the recovery method are as follows:

[0039] S1: mixing a hydrogen bond donor and a hydrogen bond acceptor in a molar ratio, stirring at a speed of 150 r / min, heating to 70° C. while stirring for 1 h, to obtain the low eutectic solvent;

[0040] S2: cooling the low eutectic solvent to room temperature, and mixing it with deionized water at a volume ratio of 1:7 at a rotation speed of 150 r / min to obtain a low eutectic solvent solution;

[0041] S3: The recycled waste lithium battery is immersed in liquid nitrogen and cooled for 2 hours at a cooling temperature of -196°C. After freezing, the battery waste is perforated first, and then the cooled waste is immersed in an electrolyte for 4 hours. The solid-liquid mass ratio of the waste lithium battery and the electrolyte is 1:5. The electrolyte is a 1 mol / L oxalic acid solution. The battery is allowed to stand and dry, and the positive electrode material is obtained after disassembly.

[0042] S4: grinding the positive electrode material in a ball mill at a speed of 500 r / min for 5 h to obtain particles with a particle size of 500 mesh, adding 0.3 wt % of a dispersant, and mixing the two uniformly to obtain waste particles;

[0043] The dispersant is modified nano-silicon dioxide, and the modification method is as follows: dissolving graphene oxide in deionized water to obtain a graphene oxide solution with a mass fraction of 50%, adding nano-silicon dioxide to the graphene oxide solution, with a solid-liquid mass ratio of 1:1, and then adding 2wt% chitosan, after ultrasonication for 1h, drying at 110°C for 8h, and then calcining at 250°C for 2h, grinding and crushing to a particle size of 500 mesh, to obtain the dispersant

[0044] S5: dispersing the waste particles into a low eutectic solvent solution, wherein the solid-liquid mass ratio of the waste particles to the low eutectic solvent solution is 1:2, stirring at a speed of 150 r / min, heating to 80°C while stirring, continuing stirring for 3 hours after constant temperature, slowly cooling to room temperature after stirring, and slowly cooling to room temperature at a rate of 2°C / min, centrifugation, the centrifugation parameters are a speed of 12000 rpm, a centrifugation time of 10 minutes, filtering, and obtaining an upper layer of clear water containing lithium and cobalt;

[0045] S6: Dry the lithium and cobalt-containing clear nightshade at 80°C for 6 hours to obtain a solid crude product containing lithium and cobalt, add 1wt% of urea to the solid crude product of lithium and cobalt, grind it in a ball mill at 400r / min for 1 hour, transfer it to a muffle furnace preheated to 250°C and burn it for 3 minutes, then heat it to 500°C and roast it for 4 hours. The heating rate of the muffle furnace is 5°C / min. After roasting, cool and grind to obtain a solid product of lithium and cobalt. The particle size of the ground solid product of lithium and cobalt is 200 mesh, and the recovery is completed.

[0046] Example 2

[0047] A method for recovering lithium and cobalt from waste lithium battery positive electrode materials using a deep eutectic solvent, wherein the deep eutectic solvent comprises glycerol and choline chloride in a molar ratio of 1:1.

[0048] The specific steps of the recovery method are as follows:

[0049] S1: mixing a hydrogen bond donor and a hydrogen bond acceptor in a molar ratio, stirring at a speed of 200 r / min, heating to 60° C. while stirring for 2 h, to obtain the low eutectic solvent;

[0050] S2: Cooling the low eutectic solvent to room temperature, and mixing it with deionized water at a volume ratio of 1:5 at a rotation speed of 150 r / min to obtain a low eutectic solvent solution;

[0051] S3: The recycled waste lithium battery is immersed in liquid nitrogen and cooled for 2 hours at a cooling temperature of -196°C. After freezing, the battery waste is perforated first, and then the cooled waste is immersed in an electrolyte for 3 hours. The solid-liquid mass ratio of the waste lithium battery and the electrolyte is 1:5. The electrolyte is a 1 mol / L oxalic acid solution. The battery is allowed to stand and dry, and the positive electrode material is obtained after disassembly.

[0052] S4: grinding the positive electrode material in a ball mill at a speed of 500 r / min for 4 h to obtain particles with a particle size of 500 mesh, adding 0.3 wt % of a dispersant, and mixing the two uniformly to obtain waste particles;

[0053] The dispersant is modified nano-silicon dioxide, and the modification method is as follows: dissolving graphene oxide in deionized water to obtain a graphene oxide solution with a mass fraction of 50%, adding nano-silicon dioxide to the graphene oxide solution, with a solid-liquid mass ratio of 1:1, and then adding 2wt% chitosan, after ultrasonication for 1h, drying at 110°C for 8h, and then calcining at 250°C for 2h, grinding and crushing to a particle size of 500 mesh, to obtain the dispersant

[0054] S5: dispersing the waste particles into a low eutectic solvent solution, wherein the solid-liquid mass ratio of the waste particles to the low eutectic solvent solution is 1:1, stirring at a speed of 150 r / min, heating to 100°C while stirring, and continuing stirring for 2 hours after constant temperature, and slowly cooling to room temperature after stirring, and the rate of slowly cooling to room temperature is 2°C / min, centrifugation, and the parameters of the centrifugation are a speed of 12000 rpm and a centrifugation time of 12 minutes, filtering, and obtaining an upper layer of clear water containing lithium and cobalt;

[0055] S6: Dry the lithium and cobalt-containing clear nightshade at 80°C for 6 hours to obtain a solid crude product containing lithium and cobalt, add 1wt% of urea to the solid crude product of lithium and cobalt, grind it in a ball mill at 400r / min for 1 hour, transfer it to a muffle furnace preheated to 300°C and burn it for 2 minutes, then heat it to 500°C and roast it for 4 hours. The heating rate of the muffle furnace is 5°C / min. After roasting, cool and grind to obtain a solid product of lithium and cobalt. The particle size of the ground solid product of lithium and cobalt is 200 mesh, and the recovery is completed.

[0056] Example 3

[0057] A method for recovering lithium and cobalt from waste lithium battery positive electrode materials using a low eutectic solvent, wherein the low eutectic solvent comprises glucose and proline in a molar ratio of 1:3.

[0058] The specific steps of the recovery method are as follows:

[0059] S1: mixing a hydrogen bond donor and a hydrogen bond acceptor in a molar ratio, stirring at a speed of 150 r / min, heating to 60° C. while stirring, and stirring for 1 h to obtain the low eutectic solvent;

[0060] S2: Cooling the low eutectic solvent to room temperature, mixing it with deionized water at a volume ratio of 1:10 at a rotation speed of 150 r / min to obtain a low eutectic solvent solution;

[0061] S3: The recycled waste lithium battery is immersed in liquid nitrogen and cooled for 2 hours at a cooling temperature of -196°C. After freezing, the battery waste is perforated first, and then the cooled waste is immersed in an electrolyte for 5 hours. The solid-liquid mass ratio of the waste lithium battery and the electrolyte is 1:5. The electrolyte is a 1 mol / L oxalic acid solution. The battery is allowed to stand and dry, and the positive electrode material is obtained after disassembly.

[0062] S4: grinding the positive electrode material in a ball mill at a speed of 500 r / min for 4 h to obtain particles with a particle size of 500 mesh, adding 0.3 wt % of a dispersant, and mixing the two uniformly to obtain waste particles;

[0063] The dispersant is modified nano-silicon dioxide, and the modification method is as follows: dissolving graphene oxide in deionized water to obtain a graphene oxide solution with a mass fraction of 50%, adding nano-silicon dioxide to the graphene oxide solution, with a solid-liquid mass ratio of 1:1, and then adding 2wt% chitosan, after ultrasonication for 1h, drying at 110°C for 8h, and then calcining at 250°C for 2h, grinding and crushing to a particle size of 500 mesh, to obtain the dispersant

[0064] S5: dispersing the waste particles into a low eutectic solvent solution, wherein the solid-liquid mass ratio of the waste particles to the low eutectic solvent solution is 1:3, stirring at a speed of 150 r / min, heating to 80°C while stirring, continuing stirring for 2 hours after constant temperature, slowly cooling to room temperature after stirring, and slowly cooling to room temperature at a rate of 2°C / min, centrifuging, and centrifuging at a speed of 12000 rpm and a centrifugal time of 8 minutes, filtering to obtain a clear solution containing lithium and cobalt on the upper layer;

[0065] S6: Dry the lithium and cobalt-containing clear nightshade at 80°C for 6 hours to obtain a solid crude product containing lithium and cobalt, add 1wt% of urea to the solid crude product of lithium and cobalt, grind it in a ball mill at 400r / min for 1 hour, transfer it to a muffle furnace preheated to 250°C and burn it for 2 minutes, then heat it to 500°C and roast it for 4 hours. The heating rate of the muffle furnace is 5°C / min. After roasting, cool and grind to obtain a solid product of lithium and cobalt. The particle size of the ground solid product of lithium and cobalt is 200 mesh, and the recovery is completed.

[0066] Comparative Example 1

[0067] In this comparative example, graphene oxide was not added during the modification process of the S4 dispersant, and the remaining steps were consistent with Example 1.

[0068] Comparative Example 2

[0069] In this comparative example, chitosan was not added during the modification process of the S4 dispersant, and the remaining steps were consistent with those of Example 1.

[0070] Comparative Example 3

[0071] In this comparative example, the dispersant is not modified in S4, and the remaining steps are consistent with those in Example 1.

[0072] Comparative Example 4

[0073] In this comparative example, urea is not added to the solid crude product of lithium and cobalt in S6, and the remaining steps are consistent with Example 1.

[0074] The recovery rates of lithium and cobalt in the embodiments and comparative examples were tested. The recovery rate test was performed by measuring the lithium and cobalt content in the solid product and the lithium and cobalt content in the lithium battery positive electrode material to calculate the percentage. The experimental results are summarized in the following table:

[0075]

[0076]

[0077] Experimental data show that modification of the dispersant and addition of urea to the crude solid products of lithium and cobalt during the recovery roasting process effectively improve the recovery rates of lithium and cobalt.

[0078] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for recovering lithium and cobalt from waste lithium battery positive electrode materials using a deep eutectic solvent, characterized in that: The low eutectic solvent comprises a hydrogen bond donor and a hydrogen bond acceptor, the molar ratio of the two being 1:(1-3), The specific steps of the method are as follows: S1: mixing a hydrogen bond donor and a hydrogen bond acceptor in a molar ratio, stirring at a speed of 150 to 200 r / min, heating to 60 to 70° C. while stirring, and stirring for 1 to 2 h to obtain the low eutectic solvent; S2: Cooling the low eutectic solvent to room temperature, mixing it with deionized water at a volume ratio of 1:(5-10) at a rotation speed of 150 r / min to obtain a low eutectic solvent solution; S3: The recycled waste lithium battery is immersed in liquid nitrogen and cooled for 2 hours at a cooling temperature of -196°C. After freezing, the battery waste is perforated first, and then the cooled waste is immersed in an electrolyte for 3 to 5 hours. The electrolyte is a 1 mol / L oxalic acid solution, and then allowed to stand and dry. After disassembly, the positive electrode material is obtained; S4: grinding the positive electrode material in a ball mill at a speed of 500 r / min for 4 to 5 hours to obtain particles with a particle size of 500 mesh, adding 0.3 wt% of a dispersant, and mixing the two evenly to obtain waste particles; S5: dispersing the waste particles into a low eutectic solvent solution, stirring at a speed of 150 r / min, heating to 80-100° C. while stirring, continuing stirring for 2-3 hours after constant temperature, slowly cooling to room temperature after stirring, centrifugation, filtering, and obtaining an upper layer of clear solution containing lithium and cobalt; S6: drying the clear solution containing lithium and cobalt at 80° C. for 6 h to obtain a solid crude product containing lithium and cobalt, adding 1 wt% urea to the solid crude product of lithium and cobalt, grinding it in a ball mill at 400 r / min for 1 h, transferring it to a muffle furnace preheated to 250-300° C. for combustion for 2-3 min, and then heating it to 500° C. for roasting for 4 h. After the roasting is completed, cooling and grinding are performed to obtain a solid product of lithium and cobalt, and the recovery is completed; The hydrogen bond donor is one or more of citric acid, glycerol, and glucose; The hydrogen bond acceptor is one of choline chloride and proline; The dispersant in S4 is modified nano-silicon dioxide, and the modification method is as follows: dissolving graphene oxide in deionized water to prepare a graphene oxide solution with a mass fraction of 50%, adding nano-silicon dioxide to the graphene oxide solution with a solid-liquid mass ratio of 1:1, and then adding 2wt% chitosan. After ultrasonic treatment for 1 hour, drying at 110°C for 8 hours, and then calcining at 250°C for 2 hours, grinding and crushing to a particle size of 500 mesh, to obtain the dispersant.

2. The method for recovering lithium and cobalt from waste lithium battery positive electrode materials using a deep eutectic solvent according to claim 1, characterized in that: The solid-liquid mass ratio of the waste lithium batteries and the electrolyte in S3 is 1:

5.

3. The method for recovering lithium and cobalt from waste lithium battery positive electrode materials using a deep eutectic solvent according to claim 1, characterized in that: The solid-liquid mass ratio of the waste particles to the low eutectic solvent solution in S5 is 1:(1-3).

4. The method for recovering lithium and cobalt from waste lithium battery positive electrode materials using a deep eutectic solvent according to claim 1, characterized in that: The rate of slowly cooling to room temperature in S5 is 2°C / min.

5. The method for recovering lithium and cobalt from waste lithium battery positive electrode materials using a deep eutectic solvent according to claim 1, characterized in that: The parameters of the centrifugal separation in S5 are a rotation speed of 12000 rpm and a centrifugal time of 8 to 12 minutes.

6. The method for recovering lithium and cobalt from waste lithium battery positive electrode materials using a deep eutectic solvent according to claim 1, characterized in that: The heating rate of the muffle furnace in S6 is 5°C / min.

7. The method for recovering lithium and cobalt from waste lithium battery positive electrode materials using a deep eutectic solvent according to claim 1, characterized in that: The particle size of the solid product of lithium and cobalt obtained by grinding in S6 is 200 mesh.

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