Flash repairing and recycling process for lithium cobalt oxide battery positive electrode material

Abstract

The invention relates to a flash repair and recovery process for a lithium cobalt oxide battery positive electrode material, and belongs to the technical field of battery materials. A lithium source, a manganese source and a nickel source are introduced, the introduction of the lithium source is used for supplementing lithium possibly lost due to cyclic charging and discharging in the use process of the battery, the doping of manganese can improve the structural stability of the battery, and a new electrochemical active site is introduced; by doping nickel, the energy density and rate capability of the lithium cobalt oxide material can be improved, and the conductivity of the material is increased; chitosan and polyvinyl alcohol are mixed for use, chitosan provides cohesiveness and stability, PVA adjusts viscosity and promotes dispersion, under the combined action of chitosan and polyvinyl alcohol, the added lithium source, manganese source, nickel source and other repairing materials can be better attached to the surface of the positive pole piece, and the overall performance of the positive pole piece is improved; the graphene oxide is added to improve the performance of the repaired positive electrode material, and the graphene oxide can uniformly coat the surface of the lithium cobalt oxide positive electrode material to form a protective layer.

Description

Technical Field

[0001] The invention belongs to the technical field of battery materials and relates to a flash repair and recycling process for positive electrode materials of lithium cobalt oxide batteries. Background Art

[0002] Lithium cobalt oxide is an important material widely used in lithium-ion batteries and other fields. With the popularization of electronic products and the rise of electric vehicles, the demand for lithium cobalt oxide continues to increase. However, due to its scarce resources and the risk of environmental pollution, the recycling of lithium cobalt oxide has become particularly important.

[0003] Currently, the recycling of lithium cobalt oxide that attracts more attention is mainly pyrometallurgy or hydrometallurgy, but pyrometallurgy requires high-temperature treatment, which is demanding on equipment and consumes too much energy. Hydrometallurgy mostly uses inorganic strong acid for leaching, which releases sulfur dioxide and nitrogen-containing harmful gases, polluting the environment. Summary of the invention

[0004] The purpose of the present invention is to provide a flash repair and recovery process for positive electrode materials of lithium cobalt oxide batteries, which has the characteristics of stable performance.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A flash repair and recycling process for positive electrode materials of lithium cobalt oxide batteries, the specific process of the process is as follows:

[0007] S1: Soak the lithium cobalt oxide battery in a phosphate solution to consume the remaining power in the battery through an electrolysis process for 8 to 12 hours;

[0008] S2: After the immersion is completed, the battery is washed with deionized water, and the battery is disassembled to obtain the positive electrode sheet of the lithium cobalt oxide battery;

[0009] S3: Soak the lithium cobalt oxide positive electrode sheet in an organic solvent for 2 to 4 hours, wherein the solid-liquid ratio of the lithium cobalt oxide positive electrode sheet to the organic solvent is 1:(5 to 8) mg / ml, remove the binder on the surface, and then wash it with a 30% ethanol solution by mass. After washing, purge the surface of the lithium cobalt oxide battery positive electrode sheet with nitrogen at 50 to 70° C. and a flow rate of 8 to 10 m / s for 1 to 2 hours to obtain a dry lithium cobalt oxide battery positive electrode sheet;

[0010] S4: grinding the dried cobalt oxide lithium battery positive electrode sheet in a ball mill at a speed of 400 r / min for 2 to 3 hours to obtain cobalt oxide lithium battery positive electrode sheet powder with a particle size of 150 mesh, and then adding 5 to 7 wt% of lithium source, 3 to 5 wt% of manganese source, and 2 to 3 wt% of nickel source to the cobalt oxide lithium battery positive electrode sheet powder, and then continuing to grind in the ball mill at a speed of 500 r / min for 1 to 2 hours to obtain a mixture A, and the particle size of the mixture A is 200 mesh;

[0011] S5: mixing chitosan and polyvinyl alcohol in a mass ratio of (1-3):1, dissolving the mixture in a 5% by mass acetic acid solution to prepare a mixed solution B with a mass fraction of 20-30%;

[0012] S6: Dispersing the mixture A in the mixed solution B, ultrasonicating for 0.5 to 2 hours, and preparing a solid-liquid mixture C with a solid-liquid ratio of 1: (5 to 10) mg / ml;

[0013] S7: freezing the solid-liquid mixture C in liquid nitrogen for 10 to 15 minutes, drying it at -50°C under vacuum for 2 to 4 hours, and grinding the dried solid to obtain a mixture D;

[0014] S8: Mixing the mixture D and graphene oxide in a mass ratio of (10-12):1, adding 1-2 wt% of a dispersant, sintering at 300-350° C. for 1-2 h, and crushing to obtain a preliminarily repaired lithium cobalt oxide positive electrode powder;

[0015] S9: performing flash Joule heat treatment on the initially repaired lithium cobalt oxide positive electrode powder to obtain a repaired lithium cobalt oxide positive electrode material.

[0016] Furthermore, the phosphate in the phosphate solution in S1 is one or more of sodium phosphate, potassium phosphate, and magnesium phosphate.

[0017] Furthermore, the concentration of the phosphate solution in S1 is 5-7 wt %.

[0018] Furthermore, the voltage of the used lithium cobalt oxide battery after discharge in S1 is between 1.6V and 2.2V.

[0019] Furthermore, the organic solvent in S3 is one or more of N,N-dimethylformamide, N,N-dimethylacetamide, and dimethyl sulfoxide.

[0020] Furthermore, the lithium source in S4 is one of lithium nitrate and lithium carbonate.

[0021] Furthermore, the manganese source in S4 is one of manganese chloride, manganese carbonate and manganese sulfate.

[0022] Furthermore, the nickel source in S4 is one of nickel phosphate, nickel sulfate and nickel carbonate.

[0023] Furthermore, the dispersant in S8 is polyethylene glycol, and the number average molecular weight is 1000-2000.

[0024] Furthermore, the flash Joule heat treatment parameters in S9 are a time of 15 to 30 seconds and a temperature of 1200 to 1800°C.

[0025] The present invention immerses the lithium cobalt oxide battery in a phosphate solution, consumes the remaining power in the battery through an electrolysis process, and ensures the efficiency and safety of the battery in subsequent processing. The electrolysis process is gentle and will not cause severe damage to the internal structure of the battery.

[0026] Use deionized water to wash the battery, remove surface impurities and residues, and then soak the lithium cobalt oxide positive electrode in an organic solvent to remove the surface binder, making it easier to separate the active material. Use ethanol solution washing and nitrogen purge to further remove the residue and dry the electrode. After removing the binder, the purity of the active material is higher, which is conducive to subsequent processing; nitrogen purge can quickly dry the electrode to avoid the performance degradation that may be caused by long-term high-temperature treatment.

[0027] The dried positive electrode sheets of lithium cobalt oxide batteries are ground into powder to increase their specific surface area and improve their reaction activity; the grinding process can refine the particles and improve the uniformity of the material.

[0028] The solid-liquid mixture is frozen in liquid nitrogen and then dried at low temperature under vacuum. This process can remove the solvent in the mixture while keeping its microstructure intact. The freeze-drying process can avoid the performance degradation and structural damage that may be caused by high-temperature treatment. Low-temperature drying can retain the original properties of the material and improve the repair effect. The addition of graphene oxide can enhance the conductivity and structural stability of the material.

[0029] High-temperature sintering is then used to promote chemical reactions and interactions between the components to form a stable repair layer. The flash Joule heat treatment process is fast and efficient, and can avoid the performance degradation that may be caused by long-term high-temperature treatment. The treated lithium cobalt oxide positive electrode material has better electrochemical properties and cycle stability.

[0030] The addition of lithium source is mainly to replenish the lithium that may be lost due to cyclic charge and discharge during the use of the battery. Lithium cobalt oxide is the positive electrode material of lithium-ion batteries. During the charge and discharge process, lithium ions will migrate between the positive and negative electrodes, and some lithium ions may not be completely embedded back into the positive electrode material due to interface side reactions or material structure changes, resulting in a decrease in material performance. The replenishment of lithium source helps to restore the stoichiometric ratio of the material and improve its electrochemical performance. By replenishing the lithium source, the changes in material structure caused by lithium loss can be reduced, thereby improving the cycle stability of the battery. The replenishment of lithium source helps to restore the reversible capacity of the positive electrode material, allowing the battery to store more electrical energy.

[0031] The addition of manganese source is mainly to introduce manganese element, and improve the performance of lithium cobalt oxide material by manganese doping. Manganese doping can change the crystal structure of the material, improve its structural stability, and introduce new electrochemical active sites. Manganese doping also helps to enhance the structural stability of lithium cobalt oxide material and reduce structural changes during the charge and discharge process. In addition, the introduction of manganese can improve the cycle performance of the material, so that the battery can still maintain good performance after multiple charge and discharge.

[0032] The addition of nickel source is mainly to introduce nickel element, and improve the energy density and rate performance of lithium cobalt oxide material by nickel doping. Nickel doping can increase the conductivity of the material and introduce more lithium storage sites. Nickel doping helps to improve the energy density of lithium cobalt oxide material, so that the battery can store more electrical energy. The introduction of nickel can improve the rate performance of the material, so that the battery can still maintain a high capacity and efficiency during rapid charging and discharging.

[0033] Chitosan is a natural polymer material with good biocompatibility, degradability and film-forming properties. In the process of repairing lithium cobalt oxide positive electrode materials, chitosan is mainly used as a binder and stabilizer, which helps to firmly attach the repair material to the surface of the positive electrode and improve its structural stability. Chitosan can enhance the adhesion between the repair material and the positive electrode to prevent it from falling off during subsequent processing. The film-forming property of chitosan helps to form a protective film on the surface of the positive electrode, improving the chemical stability and thermal stability of the material.

[0034] Polyvinyl alcohol (PVA) is a common water-soluble polymer material with good film-forming properties and mechanical properties. In the repair process, PVA mainly acts as a thickener and dispersant, which helps to adjust the viscosity and stability of mixed solution B so that mixture A can be evenly dispersed in it. The addition of PVA can adjust the viscosity of mixed solution B, making it easier to operate and handle. The dispersing effect of PVA helps mixture A to be evenly dispersed in mixed solution B to form a stable solid-liquid mixture C.

[0035] Chitosan and polyvinyl alcohol can play a synergistic role when used in combination. Chitosan provides adhesion and stability, while PVA adjusts viscosity and promotes dispersion. The combined effect of the two enables the added lithium source, manganese source, nickel source and other repair materials to better adhere to the surface of the positive electrode and improve its overall performance. The subsequent freeze-drying reaction further fixes the repair material on the surface of the positive electrode. The mixed use of chitosan and polyvinyl alcohol can significantly improve the effect of repairing lithium cobalt oxide positive electrode materials, and significantly improve the electrochemical performance, structural stability and cycle life of the repaired positive electrode materials.

[0036] The present invention also adds graphene oxide to improve the performance of the repaired positive electrode material. Graphene oxide can be evenly coated on the surface of the lithium cobalt oxide positive electrode material to form a protective layer. This coating layer can not only prevent further damage to the positive electrode material during subsequent processing, but also improve the overall stability of the material. After being coated on the surface of lithium cobalt oxide, it can significantly improve the conductivity of the positive electrode material, reduce the internal resistance of the battery, and thus improve the charging and discharging efficiency and cycle stability of the battery; under high voltage or high temperature conditions, the lithium cobalt oxide positive electrode material is prone to electrolyte decomposition and active material dissolution side reactions, and the graphene oxide coating layer can effectively inhibit the occurrence of these side reactions and protect the structural integrity of the positive electrode material; the graphene oxide coating layer can reduce the direct contact between the active material and the electrolyte, reduce the probability of side reactions, and thus extend the service life of the battery; the conductivity of graphene oxide helps to improve the electron transmission efficiency of the positive electrode material, so that the battery can more fully utilize the active material during the charging and discharging process, thereby improving the energy density of the battery.

[0037] Beneficial effects of the present invention:

[0038] (1) The present invention introduces a lithium source, a manganese source and a nickel source. The introduction of the lithium source is mainly to supplement the lithium that may be lost due to cyclic charge and discharge during the use of the battery; the performance of the lithium cobalt oxide material is improved by manganese doping, which can change the crystal structure of the material, improve its structural stability, and introduce new electrochemical active sites; the energy density and rate performance of the lithium cobalt oxide material are improved by nickel doping. Nickel doping can increase the conductivity of the material and introduce more lithium storage sites. Nickel doping helps to improve the energy density of the lithium cobalt oxide material, allowing the battery to store more electrical energy;

[0039] (2) The present invention adds chitosan and polyvinyl alcohol for mixed use. Chitosan provides adhesion and stability, while PVA adjusts viscosity and promotes dispersion. The combined effect of the two enables the added repair materials such as lithium source, manganese source, nickel source to better adhere to the surface of the positive electrode sheet and improve its overall performance, so that the repaired positive electrode material is significantly improved in terms of electrochemical performance, structural stability and cycle life;

[0040] (3) The present invention adds graphene oxide to improve the performance of the repaired positive electrode material. Graphene oxide can be evenly coated on the surface of the lithium cobalt oxide positive electrode material to form a protective layer. This coating layer can not only prevent further damage to the positive electrode material during subsequent processing, but also improve the overall stability of the material. DETAILED DESCRIPTION

[0041] 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.

[0042] Example 1

[0043] S1: Soak the lithium cobalt oxide battery in a sodium phosphate solution with a concentration of 6wt% to consume the remaining power in the battery through an electrolysis process. The soaking time is 10h, and the voltage of the waste lithium cobalt oxide battery after discharge is 2.0V;

[0044] S2: After the immersion is completed, the battery is washed with deionized water, and the battery is disassembled to obtain the positive electrode sheet of the lithium cobalt oxide battery;

[0045] S3: Soak the lithium cobalt oxide positive electrode sheet in N, N-dimethylformamide for 3 hours, the solid-liquid ratio of the lithium cobalt oxide positive electrode sheet to N, N-dimethylformamide is 1:5 mg / ml, remove the binder on the surface, and then wash it with a 30% mass fraction ethanol solution. After washing, use nitrogen at 70°C and a flow rate of 8m / s to purge the surface of the lithium cobalt oxide battery positive electrode sheet for 1 hour to obtain a dry lithium cobalt oxide battery positive electrode sheet;

[0046] S4: Grind the dried cobalt oxide lithium battery positive electrode sheet in a ball mill at a speed of 400 r / min for 2 to 3 hours to obtain cobalt oxide lithium battery positive electrode sheet powder with a particle size of 150 meshes, then add 7wt% lithium nitrate, 3wt% manganese chloride, and 2wt% nickel phosphate to the cobalt oxide lithium battery positive electrode sheet powder, and continue grinding in the ball mill at a speed of 500 r / min for 2 hours to obtain a mixture A, and the particle size of the mixture A is 200 meshes;

[0047] S5: chitosan and polyvinyl alcohol are mixed in a mass ratio of 2:1, and dissolved in a 5% by mass acetic acid solution to prepare a mixed solution B with a mass fraction of 30%;

[0048] S6: Dispersing the mixture A in the mixed solution B, ultrasonicating for 1 h, and preparing a solid-liquid mixture C with a solid-liquid ratio of 1:7 mg / ml;

[0049] S7: freezing the solid-liquid mixture C in liquid nitrogen for 15 min, drying it at -50°C under vacuum for 4 h, and grinding the dried solid to obtain a mixture D;

[0050] S8: Mix the mixture D and graphene oxide in a mass ratio of 10:1, add 1wt% polyethylene glycol 2000, sinter at 350°C for 1h, and crush to obtain a preliminarily repaired lithium cobalt oxide positive electrode powder;

[0051] S9: performing flash Joule heat treatment on the initially repaired lithium cobalt oxide positive electrode powder, wherein the flash Joule heat treatment parameters are time 20s and temperature 1500°C to obtain a repaired lithium cobalt oxide positive electrode material.

[0052] Example 2

[0053] S1: The lithium cobalt oxide battery is immersed in a potassium phosphate solution with a concentration of 5wt%, and the remaining power in the battery is consumed by an electrolysis process. The immersion time is 12h, and the voltage of the waste lithium cobalt oxide battery after discharge is 2.2V;

[0054] S2: After the immersion is completed, the battery is washed with deionized water, and the battery is disassembled to obtain the positive electrode sheet of the lithium cobalt oxide battery;

[0055] S3: Soak the lithium cobalt oxide positive electrode sheet in N, N-dimethylacetamide for 2 hours, with the solid-liquid ratio of the lithium cobalt oxide positive electrode sheet to the organic solvent being 1:5 mg / ml, to remove the binder on the surface, and then wash it with a 30% mass fraction ethanol solution. After washing, use nitrogen at 50°C and a flow rate of 10 m / s to purge the surface of the lithium cobalt oxide battery positive electrode sheet for 2 hours to obtain a dry lithium cobalt oxide battery positive electrode sheet;

[0056] S4: grinding the dried cobalt oxide lithium battery positive electrode sheet in a ball mill at a speed of 400 r / min for 2 to 3 hours to obtain cobalt oxide lithium battery positive electrode sheet powder with a particle size of 150 mesh, and then adding 5wt% lithium carbonate, 5wt% manganese carbonate, and 3wt% nickel sulfate to the cobalt oxide lithium battery positive electrode sheet powder, and then continuing to grind in the ball mill at a speed of 500 r / min for 1 hour to obtain a mixture A, and the particle size of the mixture A is 200 mesh;

[0057] S5: chitosan and polyvinyl alcohol are mixed in a mass ratio of 1:1, and dissolved in a 5% by mass acetic acid solution to prepare a mixed solution B with a mass fraction of 20%;

[0058] S6: Disperse the mixture A in the mixed solution B, and perform ultrasonication for 0.5 h to obtain a solid-liquid mixture C with a solid-liquid ratio of 1:5 mg / ml;

[0059] S7: freezing the solid-liquid mixture C in liquid nitrogen for 10 min, drying it at -50°C under vacuum for 2 h, and grinding the dried solid to obtain a mixture D;

[0060] S8: Mixing the mixture D and graphene oxide in a mass ratio of 12:1, adding 2 wt % of polyethylene glycol 1000, sintering at 300° C. for 2 h, and crushing to obtain a preliminarily repaired lithium cobalt oxide positive electrode powder;

[0061] S9: performing flash Joule heat treatment on the initially repaired lithium cobalt oxide positive electrode powder, wherein the flash Joule heat treatment parameters are time 15s and temperature 1800°C to obtain a repaired lithium cobalt oxide positive electrode material.

[0062] Example 3

[0063] S1: The lithium cobalt oxide battery is immersed in a magnesium phosphate solution with a concentration of 7wt%, and the remaining power in the battery is consumed by an electrolysis process. The immersion time is 12h, and the voltage of the waste lithium cobalt oxide battery after discharge is 1.6V;

[0064] S2: After the immersion is completed, the battery is washed with deionized water, and the battery is disassembled to obtain the positive electrode sheet of the lithium cobalt oxide battery;

[0065] S3: Soak the lithium cobalt oxide positive electrode sheet in dimethyl sulfoxide for 4 hours, with the solid-liquid ratio of the lithium cobalt oxide positive electrode sheet to the organic solvent being 1:8 mg / ml, remove the binder on the surface, and then wash it with a 30% mass fraction ethanol solution. After washing, use nitrogen at 70°C and a flow rate of 10m / s to purge the surface of the lithium cobalt oxide battery positive electrode sheet for 2 hours to obtain a dry lithium cobalt oxide battery positive electrode sheet;

[0066] S4: Grind the dried cobalt oxide lithium battery positive electrode sheet in a ball mill at a speed of 400 r / min for 3 hours to obtain cobalt oxide lithium battery positive electrode sheet powder with a particle size of 150 mesh, then add 7wt% lithium nitrate, 3wt% manganese sulfate, and 2wt% nickel carbonate to the cobalt oxide lithium battery positive electrode sheet powder, and continue grinding in the ball mill at a speed of 500 r / min for 2 hours to obtain a mixture A, and the particle size of the mixture A is 200 mesh;

[0067] S5: chitosan and polyvinyl alcohol are mixed in a mass ratio of 3:1, and dissolved in a 5% by mass acetic acid solution to prepare a mixed solution B with a mass fraction of 30%;

[0068] S6: Dispersing the mixture A in the mixed solution B, ultrasonicating for 2 h, and preparing a solid-liquid mixture C with a solid-liquid ratio of 1:10 mg / ml;

[0069] S7: freezing the solid-liquid mixture C in liquid nitrogen for 15 min, drying it at -50°C under vacuum for 4 h, and grinding the dried solid to obtain a mixture D;

[0070] S8: Mix the mixture D and graphene oxide in a mass ratio of 10:1, add 2 wt % of polyethylene glycol 1000, sinter at 350° C. for 1 h, and crush to obtain a preliminarily repaired lithium cobalt oxide positive electrode powder;

[0071] S9: performing flash Joule heat treatment on the initially repaired lithium cobalt oxide positive electrode powder, wherein the flash Joule heat treatment parameters are time 30s and temperature 1200°C to obtain a repaired lithium cobalt oxide positive electrode material.

[0072] Comparative Example 1

[0073] In this comparative example, no manganese source was added, and the remaining steps were consistent with those in Example 1.

[0074] Comparative Example 2

[0075] In this comparative example, no nickel source was added, and the remaining steps were consistent with those in Example 1.

[0076] Comparative Example 3

[0077] In this comparative example, chitosan and polyvinyl alcohol were not added, and the remaining steps were consistent with those in Example 1.

[0078] Comparative Example 4

[0079] In this comparative example, graphene oxide was not added, and the remaining steps were consistent with those in Example 1.

[0080] The embodiments and comparative examples were tested, and the discharge test was carried out according to the standard GB / T 23365-2009, and the cycle retention rate test was carried out according to the standard GB / T23366-2009. The experimental results are summarized in the following table:

[0081]

[0082] Experimental data show that the introduction of manganese source, nickel source, chitosan, polyvinyl alcohol and graphene oxide improves the first-cycle discharge capacity and cycle retention rate of lithium cobalt oxide batteries.

[0083] 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 flash repair and recycling process for positive electrode materials of lithium cobalt oxide batteries. It is characterized in that The specific process of the process is as follows: S1: Soak the lithium cobalt oxide battery in a phosphate solution to consume the remaining power in the battery through an electrolysis process. The soaking time is 8 to 12 hours. S2: After the immersion is completed, the battery is washed with deionized water, and the battery is disassembled to obtain the positive electrode sheet of the lithium cobalt oxide battery; S3: Soak the lithium cobalt oxide positive electrode sheet in an organic solvent for 2 to 4 hours, wherein the solid-liquid ratio of the lithium cobalt oxide positive electrode sheet to the organic solvent is 1:(5 to 8) mg / ml, remove the binder on the surface, and then wash it with a 30% ethanol solution by mass. After washing, purge the surface of the lithium cobalt oxide battery positive electrode sheet with nitrogen at 50 to 70° C. and a flow rate of 8 to 10 m / s for 1 to 2 hours to obtain a dry lithium cobalt oxide battery positive electrode sheet; S4: grinding the dried cobalt oxide lithium battery positive electrode sheet in a ball mill at a speed of 400 r / min for 2 to 3 hours to obtain cobalt oxide lithium battery positive electrode sheet powder with a particle size of 150 mesh, and then adding 5 to 7 wt% of lithium source, 3 to 5 wt% of manganese source, and 2 to 3 wt% of nickel source to the cobalt oxide lithium battery positive electrode sheet powder, and then continuing to grind in the ball mill at a speed of 500 r / min for 1 to 2 hours to obtain a mixture A, and the particle size of the mixture A is 200 mesh; S5: mixing chitosan and polyvinyl alcohol in a mass ratio of (1-3):1, dissolving the mixture in a 5% by mass acetic acid solution to prepare a mixed solution B with a mass fraction of 20-30%; S6: Dispersing the mixture A in the mixed solution B, ultrasonicating for 0.5 to 2 hours, and preparing a solid-liquid mixture C with a solid-liquid ratio of 1: (5 to 10) mg / ml; S7: freezing the solid-liquid mixture C in liquid nitrogen for 10 to 15 minutes, drying it at -50°C under vacuum for 2 to 4 hours, and grinding the dried solid to obtain a mixture D; S8: Mixing the mixture D and graphene oxide in a mass ratio of (10-12):1, adding 1-2 wt% of a dispersant, sintering at 300-350° C. for 1-2 h, and crushing to obtain a preliminarily repaired lithium cobalt oxide positive electrode powder; S9: performing flash Joule heat treatment on the initially repaired lithium cobalt oxide positive electrode powder to obtain a repaired lithium cobalt oxide positive electrode material.

2. A flash repair and recycling process for positive electrode materials of lithium cobalt oxide batteries according to claim 1, It is characterized in that The phosphate in the phosphate solution in S1 is one or more of sodium phosphate, potassium phosphate and magnesium phosphate.

3. A flash repair and recycling process for positive electrode materials of lithium cobalt oxide batteries, It is characterized in that The concentration of the phosphate solution in S1 is 5-7 wt %.

4. A flash repair and recycling process for positive electrode materials of lithium cobalt oxide batteries, It is characterized in that The voltage of the used lithium cobalt oxide battery after discharge in S1 is between 1.6V and 2.2V.

5. A flash repair and recycling process for positive electrode materials of lithium cobalt oxide batteries. It is characterized in that The organic solvent in S3 is one or more of N,N-dimethylformamide, N,N-dimethylacetamide and dimethyl sulfoxide.

6. A flash repair and recycling process for positive electrode materials of lithium cobalt oxide batteries, It is characterized in that The lithium source in S4 is one of lithium nitrate and lithium carbonate.

7. A flash repair and recycling process for positive electrode materials of lithium cobalt oxide batteries. It is characterized in that The manganese source in the S4 is one of manganese chloride, manganese carbonate and manganese sulfate.

8. A flash repair and recycling process for positive electrode materials of lithium cobalt oxide batteries. It is characterized in that The nickel source in S4 is one of nickel phosphate, nickel sulfate and nickel carbonate.

9. A flash repair and recycling process for positive electrode materials of lithium cobalt oxide batteries. It is characterized in that The dispersant in S8 is polyethylene glycol, and the number average molecular weight is 1000-2000.

10. A flash repair and recycling process for positive electrode materials of lithium cobalt oxide batteries. It is characterized in that The flash Joule heat treatment parameters in S9 are a time of 15 to 30 seconds and a temperature of 1200 to 1800°C.

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