Method for recycling polyvinylidene fluoride from waste lithium cobalt oxide batteries and regenerating lithium cobalt oxide positive electrode materials

Abstract

The present invention discloses a method for recycling polyvinylidene fluoride and regenerating lithium cobalt oxide cathode material from waste lithium cobalt oxide batteries, belonging to the technical field of waste lithium-ion battery recycling. In the present invention, the lithium cobalt oxide battery is discharged and disassembled to obtain the waste lithium cobalt oxide cathode sheet. The waste lithium cobalt oxide cathode sheet is treated with NMP to separate the cathode waste, aluminum foil and recycle PVDF. Then, the cathode waste is mixed with an organic carbon source and subjected to reduction roasting. Next, lithium and cobalt are separated by water leaching, and lithium carbonate and cobalt tetroxide are obtained through evaporation crystallization and calcination treatment respectively. Finally, the obtained lithium carbonate and cobalt tetroxide are mixed according to the stoichiometric ratio and reacted to obtain regenerated lithium cobalt oxide. The present invention efficiently recycles waste lithium-ion battery materials and realizes the comprehensive circular regeneration of waste battery materials. Moreover, the obtained regenerated lithium cobalt oxide has high purity, excellent rate performance and cycle stability.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium battery positive electrode material recovery, and more specifically, to a method for recovering polyvinylidene fluoride from waste lithium cobalt oxide batteries and regenerating lithium cobalt oxide positive electrode materials. Background Art

[0002] Lithium-ion batteries play an important role in overcoming the inherent intermittent nature of renewable energy and promoting the development of portable electronic devices. 2 (LCO) has a high volumetric energy density and a high charge cut-off voltage. Although it is expensive, it still dominates the field of portable electronic devices. However, with the rapid growth of electronic product consumption and short-term updates, a large number of waste LCO batteries are scrapped every year. On the one hand, waste LCO batteries are rich in valuable metals Li and Co, and effective recycling can create huge economic value and achieve sustainable development of strategic resources. On the other hand, if not handled properly, the toxic electrolytes and heavy metals in these waste lithium-ion batteries will pose a serious threat to human environment and health. Therefore, it is imperative to seek a clean and efficient way to recycle waste LCO batteries and realize "turning waste into treasure".

[0003] At present, the recycling process of waste lithium-ion batteries can be divided into pyrometallurgy, hydrometallurgy, and pyrometallurgy combined with hydrometallurgy. Pyrometallurgy has the advantages of high efficiency, large processing capacity, and easy scalability, and has been widely used in industry. However, high energy consumption, high emissions, and difficulty in recovering lithium from slag are still the challenges currently faced by this type of technology. Hydrometallurgy is currently the mainstream waste battery recycling process in China. In the hydrometallurgical process, a large amount of strong acid is used in combination with a reducing agent to convert LiCoO 2 Reduction to Li + and Co 2+ In order to obtain the ideal leaching efficiency, the solid-liquid ratio is often kept at a low level during the leaching process. Subsequently, solvent extraction is used to separate Li + and Co 2+ This results in a large amount of acidic wastewater, causing additional costs for wastewater treatment.

[0004] For example, a Chinese patent application with application number CN106868371 B discloses a method for recovering spent lithium cobalt oxide positive electrode materials, wherein the aluminum foil on the spent lithium cobalt oxide positive electrode materials is removed to obtain the spent lithium cobalt oxide positive electrode materials and crush them, and then hydrochloric acid or sulfuric acid is added with ferrous sulfate as a reducing agent to carry out a chemical reaction, and after the reaction, an inorganic base is added to neutralize the residual acid and precipitate Fe 3+. The precipitate and the filtrate are separated by filtration, and an inorganic base is continuously added to the filtrate to adjust the pH value to 10.0-14.0 to precipitate cobalt, thereby separating lithium and cobalt. The process is complicated and uses a large amount of acid and alkali, which is costly and environmentally unfriendly. Chinese patent application with application number CN106505270 A discloses a method for recovering lithium and cobalt from waste lithium-ion batteries, wherein the waste pole pieces obtained by disassembly and discharge are mixed with ammonium sulfate, and high-temperature roasting is performed to obtain reduction roasting slag, and the aluminum foil is removed by vibration screening to obtain reduction slag containing lithium and cobalt, followed by leaching with sulfuric acid, and then the pH of the solution is adjusted with sodium carbonate, and the precipitate is removed by filtration; sodium hydroxide is added to the obtained sulfate precipitate of lithium and cobalt to obtain cobalt hydroxide precipitate, and the cobalt hydroxide is then reduced and roasted to obtain metallic cobalt powder; an excess amount of lithium precipitating agent is added to the remaining lithium-containing solution to obtain a lithium salt product. However, the decomposition of ammonium sulfate in this process will produce a large amount of ammonia gas, posing a threat to environmental pollution. Chinese patent application with application number CN110079671A discloses a method for recovering lithium and cobalt from waste lithium-ion batteries by using a gas reducing agent (H 2 , natural gas, liquefied petroleum gas, coal gas, etc.) to reduce and roast the crushed materials of waste lithium-ion batteries, and then recover the valuable elements. However, the process uses a large amount of flammable and explosive gases at high temperatures, causing great safety hazards. The Chinese patent application with application number CN 111430829 B discloses a method of reducing and roasting waste lithium-ion battery positive electrode materials using biomass materials (corn stalks, rapeseed cakes, rice husks, straw, sawdust and sorghum wine lees, etc.), and then regenerating and synthesizing nickel-cobalt-manganese ternary positive electrode materials. However, the process uses biomass materials to introduce impurity elements such as Na, K, Ca, and Mg, which increases the difficulty of recovering high-purity valuable components and makes it difficult to regenerate positive electrode materials with excellent electrochemical properties. The Chinese patent application with application number CN 111430829 B discloses a method of recovering lithium from waste lithium-ion batteries using graphite negative electrode powder as a reducing agent. However, this process is limited to recovering lithium from waste lithium-ion batteries and does not fully utilize valuable resources to achieve closed-loop recycling of resources. In addition, it uses graphite as a reducing agent, and the residual graphite easily adsorbs lithium in the roasting product, resulting in a lower lithium recovery rate. Summary of the invention

[0005] Based on this, the present invention provides a method for recycling polyvinylidene fluoride from waste lithium cobalt oxide batteries and regenerating lithium cobalt oxide positive electrode materials. The method realizes the cyclic regeneration of cobalt, lithium and PVDF in the lithium cobalt oxide positive electrode materials by subjecting the disassembled electrode plates to solvent immersion-reduction roasting-selective lithium leaching-calcination in sequence, thereby realizing the recovery of polyvinylidene fluoride in waste lithium cobalt oxide batteries and the regeneration of lithium cobalt oxide positive electrode materials, and further realizing the closed-loop circulation of waste lithium cobalt oxide battery materials.

[0006] In order to achieve the above object, the technical solution of the present invention is as follows:

[0007] The method for recycling polyvinylidene fluoride from waste lithium cobalt oxide batteries and regenerating lithium cobalt oxide positive electrode materials comprises the following steps:

[0008] S1. Pretreatment: discharging and disassembling waste lithium cobalt oxide batteries to obtain waste lithium cobalt oxide positive electrode sheets, immersing the waste lithium cobalt oxide positive electrode sheets in NMP (N-methylpyrrolidone) solvent and heating, filtering and separating to obtain filtrate, positive electrode waste and aluminum foil, evaporating and concentrating the filtrate, collecting gas and crystalline products to obtain NMP and PVDF (polyvinylidene fluoride), respectively;

[0009] S2, reduction roasting: mixing the cathode waste with organic carbon, and performing reduction roasting under an inert atmosphere to obtain a roasted material;

[0010] S3, soaking the calcined material in water and separating it to obtain a lithium-rich solution and an insoluble filter residue;

[0011] S4, introducing CO into the lithium-rich solution 2 And evaporate and crystallize to obtain Li 2 CO 3 powder; calcining the insoluble residue in air to obtain Co 3 O 4 powder;

[0012] S5, the Li obtained in step S4 2 CO 3 Powder and Co 3 O 4 The powders are mixed according to a stoichiometric ratio and calcined in air to obtain a regenerated lithium cobalt oxide positive electrode material;

[0013] Wherein, the organic carbon is at least one of glucose, sucrose, starch, maltose and beta-cyclodextrin.

[0014] In some embodiments, in step S2, the mass of the organic carbon added is 5-20% of the positive electrode waste.

[0015] In some embodiments, in step S2, the inert atmosphere is an argon atmosphere and / or a nitrogen atmosphere.

[0016] In some embodiments, in step S2, the calcination temperature is 400-800°C.

[0017] In some embodiments, in step S2, the calcination time is 0.5 to 3 hours.

[0018] In some embodiments, in step S3, the water-solid-to-liquid ratio is 10 to 100 g / L.

[0019] In some embodiments, in step S3, the leaching time is 5 to 60 minutes.

[0020] In some embodiments, in step S4, the insoluble filter residue is calcined at a temperature of 500 to 800°C.

[0021] In some embodiments, in step S4, the calcination time is 0.5 to 3.0 hours.

[0022] In some embodiments, in step S5, the molar ratio of Li:Co of lithium carbonate and cobalt oxide is 1:1.0-1.1.

[0023] In some embodiments, in step S5, the calcination temperature is 800-1200°C.

[0024] In some embodiments, in step S5, the calcination time is 2 to 10 hours.

[0025] In some embodiments, in step S1, the waste lithium cobalt oxide positive electrode sheet is immersed in NMP solvent and then heated to 60-100°C.

[0026] In the technical solution of the present invention, a low-cost organic carbon source is innovatively used as a reducing agent to reduce and decompose the waste lithium cobalt oxide material into soluble lithium cobalt oxide and insoluble Co and CoO during the roasting process. The inventor has found that efficient separation of lithium and cobalt can be achieved through simple water leaching. At the same time, the recovered Li 2 CO 3 and Co 3 O 4 Regenerated LiCoO 2 The positive electrode material has excellent rate performance and cycle stability. Specifically, the basic principles of the present invention are as follows:

[0027] During the reduction roasting process, at high temperature, organic carbon is pyrolyzed to form carbon, which undergoes redox reaction with cobalt and lithium molecules, converting lithium into soluble salts and cobalt into insoluble cobalt or cobalt oxide. The main chemical reactions are as follows:

[0028] C+4LiCoO 2 =2Li 2 O+4CoO+CO 2 (g) (1)

[0029] C + 2CoO = 2Co + CO 2 (g) (2)

[0030] CO 2 (g)+Li 2 O=2Li 2 CO 3 (3)

[0031] Lithium in the roasted material exists in the form of soluble lithium carbonate and lithium oxide, while cobalt exists in the form of cobalt element or cobalt oxide. Simple water leaching can achieve efficient separation of lithium and cobalt. During the water leaching process, lithium oxide reacts with water to form lithium hydroxide solution, and lithium carbonate can be dissolved in water to form lithium carbonate solution. After separation, a small amount of carbon dioxide is blown into the solution during the evaporation and crystallization process to convert lithium hydroxide into lithium carbonate, which can effectively reduce impurities in lithium carbonate and increase the purity of the regenerated lithium carbonate. The reaction of the water leaching process is as follows:

[0032] Li 1 O+H 2 O=2L i OH (4)

[0033] 2LiOH+Co 2 =Li 2 CO 2 +H 2 O (5)

[0034] The insoluble slag obtained after water immersion and separation is Co and CoO. The insoluble slag is sintered in air to generate Co 3 O 4 , then Co 3 O 4 With Li 2 CO 3 Mix according to the stoichiometric ratio to obtain the regenerated Li 2 CoO 2 Positive electrode material, realizing the recycling of Co and Li in lithium cobalt oxide positive electrode material.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] (1) The present invention can achieve comprehensive recycling of lithium cobalt oxide positive electrode materials through a simple process. Different from the prior art that uses a large amount of reducing agent for reaction, the present invention uses a small amount of organic carbon reduction roasting combined with a simple water leaching step to achieve lithium-cobalt separation, and then converts lithium hydroxide in the lithium-rich solution into lithium carbonate by introducing carbon dioxide into the lithium-rich solution, thereby improving the purity of the regenerated lithium carbonate.

[0037] (2) No acid or alkali is required during the process, which avoids the consumption of corrosive reagents and the treatment of waste acid or alkali solutions. Impurity ions are not introduced, which simplifies the regeneration of high-purity lithium carbonate.

[0038] (3) The present invention can recycle PVDF, cobalt and lithium in waste lithium cobalt oxide electrode materials, and the generated lithium carbonate and cobalt oxide are of high purity and can be directly used to generate regenerated lithium cobalt oxide. At the same time, the recycling of PVDF and solvent NMP is also achieved, realizing the comprehensive closed-loop recycling of lithium cobalt oxide positive electrode materials.

[0039] (4) The method of the present invention is safe, environmentally friendly, simple to operate, low-cost and has high resource utilization. The primary recovery rate of lithium can reach more than 98%, and the recovery rate of cobalt can reach more than 99%. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 The XRD pattern of lithium cobalt oxide regenerated in Example 1;

[0041] Figure 2 The charge and discharge curve of the lithium cobalt oxide regenerated in Example 1 at a 1C rate;

[0042] Figure 3 This is a SEM image of the lithium cobalt oxide regenerated in Example 2;

[0043] Figure 4 The cycle performance of the lithium cobalt oxide regenerated in Example 3 at a 1C rate;

[0044] Figure 5 This is the charge and discharge curve of the lithium cobalt oxide regenerated in Example 4 at a rate of 0.1C. DETAILED DESCRIPTION

[0045] Many specific details are set forth in the following description to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art can make similar modifications without violating the connotation of the present invention, so the present invention is not limited to the specific implementation disclosed below.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0047] Example 1

[0048] The method for comprehensive recycling of waste lithium cobalt oxide batteries comprises the following steps:

[0049] S1. Discharge and disassemble the waste lithium cobalt oxide battery to obtain waste lithium cobalt oxide positive electrode sheets; soak the waste lithium cobalt oxide positive electrode sheets in NMP solvent and heat them to 80°C to completely separate the positive electrode material from the aluminum foil. After removing the aluminum foil, filter the obtained filter residue to obtain the positive electrode waste powder and the filtrate to obtain the NMP solution containing PVDF; the filtrate is repeatedly used and then evaporated and concentrated, and the generated gas is condensed and recovered to obtain the NMP solvent, and the evaporated crystallized solid product is the PVDF powder, which can be recycled;

[0050] S2, taking 10 g of the positive electrode waste powder obtained in step S1, adding 1 g of glucose and mixing well, and roasting the mixture at 650° C. for 0.5 h under an argon atmosphere to obtain roasted sand;

[0051] S3, weigh 5g of the roasted sand obtained in step S2, stir and leach with 100ml of deionized water for 0.5h, filter, and obtain lithium-rich leachate and insoluble residue respectively;

[0052] S4. A small amount of carbon dioxide gas is blown into the leaching solution and evaporated and crystallized to obtain Li 2 CO 3 The insoluble residue was sintered in air at 800℃ for 0.5h to obtain Co 3 O 4 Mixed materials;

[0053] S5, the above recovered Li 2 CO 3 and Co 3 O 4 , mixed evenly according to the Li:Co molar ratio of 1:1.05, calcined at 850℃ in air for 8h, and regenerated LiCoO 2 Positive electrode material.

[0054] The water leaching rate of lithium was 98.2% and the recovery rate of cobalt was 99.1%, as measured and calculated by inductively coupled plasma emission spectroscopy (ICP).

[0055] The regenerated lithium cobalt oxide positive electrode material was tested, and the test results are as follows: Figure 1 and Figure 2 As shown. Among them, Figure 1 For this example, LiCoO 2 XRD pattern of positive electrode material, Figure 2 The regenerated LiCoO 2 The charge and discharge curve of the positive electrode material at 1C rate. Figure 1 XRD results show that the regenerated LiCoO 2 The positive electrode material has good crystal form and no impurity peaks; Figure 2 The electrochemical test results show that the regenerated LiCoO 2 The discharge specific capacity of the positive electrode material reaches 156.9mAh / g at a 1C rate.

[0056] Example 2

[0057] The method for comprehensive recycling of waste lithium cobalt oxide battery materials comprises the following steps:

[0058] S1. Discharge and disassemble the waste lithium cobalt oxide battery to obtain waste lithium cobalt oxide positive electrode sheets; soak the waste lithium cobalt oxide positive electrode sheets in NMP solvent and heat them to 80°C to completely separate the positive electrode material from the aluminum foil. After removing the aluminum foil, filter the obtained filter residue to obtain the positive electrode waste powder and the filtrate to obtain the NMP solution containing PVDF; after repeated use of the filtrate, evaporate and concentrate it, condense and recover the generated gas to obtain the NMP solvent, and evaporate and crystallize the solid product to obtain PVDF powder;

[0059] S2, taking 10g of the positive electrode waste powder, adding 2g of starch and mixing well, and calcining the mixture at 550°C for 0.5h under argon atmosphere to obtain calcined sand;

[0060] S3, weigh 5g of the above roasted sand and stir and leach it with 200ml of deionized water for 1h to obtain a lithium-rich leachate and an insoluble residue;

[0061] S4. A small amount of carbon dioxide gas is blown into the leaching solution and evaporated and crystallized to obtain Li 2 CO 3 Powder; the insoluble residue was sintered at 700℃ in air for 1h to obtain Co 3 O 4 Mixed materials;

[0062] S5, the above recovered Li 2 CO 3 and Co 3 O 4 , mixed evenly according to the Li:Co molar ratio of 1:1.03, calcined at 900℃ in air for 6h, and regenerated LiCoO 2 Positive electrode material.

[0063] The water leaching rate of lithium was 98.6% and the recovery rate of cobalt was 99.3% as measured and calculated by inductively coupled plasma emission spectroscopy (ICP).

[0064] like Figure 3 As shown in the figure, the SEM test results show that the LiCoO 2 The morphology of the positive electrode material is composed of primary particles and irregular secondary particles with a size of 2-15μm.

[0065] Example 3

[0066] The method for comprehensive recycling of waste lithium cobalt oxide battery materials comprises the following steps:

[0067] S1. Discharge and disassemble the waste lithium cobalt oxide battery to obtain waste lithium cobalt oxide positive electrode sheets; soak the waste lithium cobalt oxide positive electrode sheets in NMP solvent and heat them to 80°C to completely separate the positive electrode material from the aluminum foil. After removing the aluminum foil, filter the obtained filter residue to obtain the positive electrode waste powder and the filtrate to obtain the NMP solution containing PVDF; after repeated use of the filtrate, evaporate and concentrate it, condense and recover the generated gas to obtain the NMP solvent, and evaporate and crystallize the solid product to obtain PVDF powder;

[0068] S2, taking 10g of the positive electrode waste powder, adding 0.5g of sucrose and mixing well, and calcining the mixture at 750°C for 2h under a nitrogen atmosphere to obtain calcined sand;

[0069] S3, weigh 5g of the above roasted sand, stir and leach with 150ml of deionized water for 40min to obtain a lithium-rich leachate and an insoluble residue;

[0070] S4. A small amount of carbon dioxide gas is blown into the leaching solution and evaporated and crystallized to obtain Li 2 CO 3 The powder and insoluble residue were sintered at 700℃ in air for 1h to obtain Co 3 O 4 Mixed materials;

[0071] S5, the above recovered Li 2 CO 3 and Co 3 O 4 , mixed evenly according to the Li:Co molar ratio of 1:1.07, calcined at 800℃ in air for 10h, and regenerated LiCoO 2 Positive electrode material.

[0072] The water leaching rate of lithium was 97.6% and the recovery rate of cobalt was 99.1% as measured and calculated by inductively coupled plasma emission spectroscopy (ICP).

[0073] like Figure 4 As shown in the electrochemical test results, the LiCoO regenerated in this example 2 The capacity retention rate of the positive electrode material after 100 cycles at 1C rate is 97.8%.

[0074] Example 4

[0075] The method for comprehensive recycling of waste lithium cobalt oxide battery materials comprises the following steps:

[0076] S1. Discharge and disassemble the waste lithium cobalt oxide battery to obtain waste lithium cobalt oxide positive electrode sheets; soak the waste lithium cobalt oxide positive electrode sheets in NMP solvent and heat them to 80°C to completely separate the positive electrode material from the aluminum foil. After removing the aluminum foil, filter the obtained filter residue to obtain the positive electrode waste powder and the filtrate to obtain the NMP solution containing PVDF; after repeated use of the filtrate, evaporate and concentrate it, condense and recover the generated gas to obtain the NMP solvent, and evaporate and crystallize the solid product to obtain PVDF powder;

[0077] S2, taking 10g of the positive electrode waste powder, adding 1.5g of sucrose and mixing well, and roasting the mixture at 550°C for 1h under a nitrogen atmosphere to obtain roasted sand;

[0078] S3, weigh 5g of the above roasted sand and stir and leach it with 200ml of deionized water for 20min to obtain a lithium-rich leachate and an insoluble residue;

[0079] S4. A small amount of carbon dioxide gas is blown into the leaching solution and evaporated and crystallized to obtain Li 2 CO 3 The powder and insoluble residue were sintered in air at 800℃ for 0.5h to obtain Co 3 O 4 Mixed materials;

[0080] S5, the above recovered Li 2 CO 3 and Co 3 O 4 , mixed evenly according to the Li:Co molar ratio of 1:1.1, calcined at 900℃ in air for 10h, and regenerated LiCoO 2 Positive electrode material.

[0081] The water leaching rate of lithium was 97.9% and the recovery rate of cobalt was 99.2% as measured and calculated by inductively coupled plasma emission spectroscopy (ICP).

[0082] like Figure 5 As shown in the electrochemical test results, the LiCoO regenerated in this example 2 The discharge specific capacity of the positive electrode material at a rate of 0.1C is 163.3 mAh / g.

[0083] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0084] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. Method for recycling polyvinylidene fluoride from waste lithium cobalt oxide batteries and regenerating lithium cobalt oxide positive electrode materials. It is characterized in that The following steps are involved: S1. Pretreatment: discharging and disassembling waste lithium cobalt oxide batteries to obtain waste lithium cobalt oxide positive electrode sheets, immersing the waste lithium cobalt oxide positive electrode sheets in NMP solvent and heating, filtering and separating to obtain filtrate, positive electrode waste and aluminum foil, evaporating and concentrating the filtrate, collecting gas and crystalline products to obtain NMP and PVDF respectively; S2, reduction roasting: mixing the cathode waste with organic carbon, and performing reduction roasting under an inert atmosphere to obtain a roasted material; S3, soaking the calcined material in water and separating it to obtain a lithium-rich solution and an insoluble filter residue; S4, introducing CO into the lithium-rich solution 2 And evaporate and crystallize to obtain Li 2 CO 3 powder; calcining the insoluble residue in air to obtain Co 3 O 4 powder; S5, the Li obtained in step S4 2 CO 3 Powder and Co 3 O 4 The powders are mixed according to a stoichiometric ratio and calcined in air to obtain a regenerated lithium cobalt oxide positive electrode material; Wherein, the organic carbon is at least one of glucose, sucrose, starch, maltose and beta-cyclodextrin.

2. The method for recovering polyvinylidene fluoride and regenerating lithium cobalt oxide positive electrode material from waste lithium cobalt oxide batteries according to claim 1, It is characterized in that In step S2, the mass of the organic carbon added is 5-20% of the positive electrode waste.

3. The method for recovering polyvinylidene fluoride and regenerating lithium cobalt oxide positive electrode material from waste lithium cobalt oxide batteries according to claim 1, It is characterized in that In step S2, the inert atmosphere is an argon atmosphere and / or a nitrogen atmosphere.

4. The method for recovering polyvinylidene fluoride and regenerating lithium cobalt oxide positive electrode material from waste lithium cobalt oxide batteries according to claim 1, It is characterized in that In step S2, the calcination temperature is 400-800°C; and / or the calcination time is 0.5-3h.

5. The method for recovering polyvinylidene fluoride and regenerating lithium cobalt oxide positive electrode material from waste lithium cobalt oxide batteries according to claim 1, It is characterized in that In step S3, the water leaching solid-liquid ratio is 10 to 100 g / L; and / or the leaching time is 5 to 60 min.

6. The method for recovering polyvinylidene fluoride and regenerating lithium cobalt oxide positive electrode material from waste lithium cobalt oxide batteries according to claim 1, It is characterized in that In step S4, the insoluble filter residue is calcined at a temperature of 500 to 800° C. and / or the calcination time is 0.5 to 3.0 h.

7. The method for recovering polyvinylidene fluoride and regenerating lithium cobalt oxide positive electrode material from waste lithium cobalt oxide batteries according to claim 1, It is characterized in that In step S5, the molar ratio of Li:Co of lithium carbonate and cobalt oxide is 1:1.0-1.

1.

8. The method for recovering polyvinylidene fluoride and regenerating lithium cobalt oxide positive electrode material from waste lithium cobalt oxide batteries according to claim 1, It is characterized in that In step S5, the calcination temperature is 800-1200° C.; and / or the calcination time is 2-10 hours.

9. The method for recovering polyvinylidene fluoride and regenerating lithium cobalt oxide positive electrode material from waste lithium cobalt oxide batteries according to claim 1, It is characterized in that In step S1, the waste lithium cobalt oxide positive electrode sheet is immersed in NMP solvent and then heated to 60-100°C.

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