Method for recycling a positive electrode material and regenerated positive electrode material

Abstract

The application discloses a recycling method of a positive electrode material and a regenerated positive electrode material, and belongs to the technical field of battery material recycling. The recycling method comprises the following steps: preparing an organic nickel source shell layer on the surface of the positive electrode material, and then mixing the positive electrode material with a lithium source and sintering to obtain the regenerated positive electrode material. The method is simple in process, low in cost and friendly to the environment, and can regenerate the waste positive electrode material to obtain the regenerated positive electrode material which can be reused. The method adopts the mode of first preparing the organic nickel source shell layer on the surface of the waste positive electrode material, and then supplementing lithium sintering, compared with directly adding nickel oxide or nickel hydroxide in the recycling upgrading and remanufacturing process, the nickel source can be more uniformly dispersed on the surface of the waste positive electrode material, a larger contact area is obtained, and the nickel source and the waste positive electrode material are more closely contacted, and the obtained regenerated positive electrode material has better electrochemical performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery material recycling, in particular to a positive electrode material recycling method and regenerated positive electrode material. BACKGROUND

[0002] Lithium ion batteries are widely used in portable electronic products, electric vehicles and energy storage systems, etc. How to effectively recycle power batteries will become a key problem in recent years.

[0003] The positive electrode material (NCM and NCA) is a main positive electrode material used in lithium ion batteries. Its main recycling process includes pyrometallurgical recycling and hydrometallurgical recycling. However, the above recycling process involves high-temperature smelting, acid leaching and chemical precipitation, etc. These steps inevitably cause carbon dioxide emissions and other waste problems. Direct repair technology is a repair method that does not destroy the original material structure and restores the harmful structure to the initial state.

[0004] In recent years, most of the power battery materials are mainly low-nickel. Even if the direct repair technology is used for recycling and utilization, the corresponding regenerated material still has the problem of poor electrochemical performance (such as low specific capacity).

[0005] Therefore, the present application is proposed. SUMMARY

[0006] The present application aims to provide a positive electrode material recycling method and regenerated positive electrode material to solve or improve the above technical problems.

[0007] The present application can be achieved as follows:

[0008] In a first aspect, the present application provides a positive electrode material recycling method, which comprises the following steps: preparing an organic nickel source shell layer on the surface of the waste positive electrode material to obtain a positive electrode material precursor; and sintering the positive electrode material precursor and a lithium source to obtain a regenerated positive electrode material.

[0009] In an optional embodiment, the waste positive electrode material has a layered structure.

[0010] In an optional embodiment, the waste positive electrode material includes at least one of waste lithium nickel cobalt manganese oxide positive electrode material, waste lithium nickel cobalt aluminum oxide positive electrode material and waste lithium cobalt oxide positive electrode material.

[0011] And / or, the organic nickel source shell layer is a Ni-MOF material with a metal organic framework structure.

[0012] In an optional embodiment, the preparation of the organic nickel source shell layer comprises: mixing the waste positive electrode material and the preparation raw material of the organic nickel source shell layer, and then performing a hydrothermal reaction.

[0013] The raw materials include a nickel salt, an organic ligand, and an organic solvent.

[0014] In an optional embodiment, the nickel salt includes at least one of Ni(NO3)2, NiCl2, Ni(CH3COO)2, and Ni(SO4)2.

[0015] And / or, the organic ligand includes at least one of terephthalic acid, phthalic acid, 2,5-dihydroxyterephthalic acid, and trimesic acid.

[0016] And / or, the organic solvent includes N,N-dimethylformamide.

[0017] In an optional embodiment, the hydrothermal reaction is performed at 120-180℃ for 8-16h.

[0018] In an optional embodiment, the lithium source includes at least one of LiOH, Li2CO3, LiNO3, and CH3COOLi.

[0019] In an optional embodiment, the sintering includes a first sintering stage and a second sintering stage; wherein the first sintering stage is performed at 450-550℃ for 4-5h, the second sintering stage is performed at 750-900℃ for 8-15h, and then the temperature is decreased to 200-220℃.

[0020] In an optional embodiment, the heating rate and the cooling rate during the sintering process are both 1-12℃ / min.

[0021] And / or, the sintering is performed in an oxygen-containing atmosphere.

[0022] In an optional embodiment, the heating rate and the cooling rate during the sintering process are both 5-10℃ / min.

[0023] In an optional embodiment, the sintering is performed at an oxygen partial pressure of 0.01-1atm.

[0024] In a second aspect, the present application provides a regenerated positive electrode material, which is obtained by treating a waste positive electrode material by the recycling method of any one of the preceding embodiments.

[0025] The beneficial effects of the present application include:

[0026] The application adopts the mode of first preparing an organic nickel source shell layer on the surface of the waste positive electrode material, and then performing lithium supplement sintering, compared with directly adding nickel oxide or hydroxide in the recycling and upgrading process, the nickel source can be more uniformly dispersed on the surface of the waste positive electrode material, a larger contact area is obtained, and the contact between the nickel source and the waste positive electrode material is more closely, and the obtained regenerated positive electrode material has better electrochemical performance. The method is simple in process, low in cost, and friendly to the environment, and can regenerate the waste positive electrode material to obtain a regenerated positive electrode material which can be reused. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0028] Figure 1 SEM image of the waste positive electrode material powder in Example 1;

[0029] Figure 2 SEM image of the regenerated positive electrode material in Example 1;

[0030] Figure 3 SEM image of the regenerated positive electrode material in Comparative Example 1. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below. If the specific conditions are not specified in the embodiments, the conventional conditions or the conditions recommended by the manufacturer are used. If the reagents or instruments used are not specified by the manufacturer, they are all conventional products that can be purchased on the market.

[0032] The recycling method of the positive electrode material and the regenerated positive electrode material provided in the present application will be specifically described below.

[0033] Some current technologies increase the nickel content to improve the specific capacity of the medium-low nickel regenerated positive electrode material, but the inventors propose that if the nickel oxide or hydroxide is directly used as the nickel source to perform high-temperature nickel supplement by solid phase sintering, in the solid phase sintering process, due to the high melting point of the nickel oxide, it is difficult to reach the molten state at a suitable sintering temperature, resulting in a small contact area between the waste positive electrode material and the nickel source, which is not conducive to the diffusion of nickel, and thus the contact between the waste positive electrode material and the nickel oxide or hydroxide is poor during the sintering process, and the nickel element is difficult to diffuse uniformly, so that the electrochemical performance of the sintered material is still difficult to be effectively improved.

[0034] Based on this, the application creatively proposes to use a liquid phase method to prepare an organic nickel source shell layer on the surface of the waste positive electrode material. This method can make the nickel source more uniformly dispersed on the surface of the waste positive electrode material, obtain a larger contact area, and make the contact between the nickel source and the waste positive electrode material more close, which is beneficial to improve the electrochemical performance of the regenerated positive electrode material.

[0035] It should be emphasized that the "medium-low nickel" in the application can be understood as follows: before increasing the nickel, the relative content of nickel in the positive electrode material is low. After increasing the nickel, the relative content of nickel in the positive electrode material is high, which can be correspondingly referred to as "high nickel". Therefore, the application does not specifically limit the nickel content of the regenerated positive electrode material before increasing the nickel, and any positive electrode material with a nickel content can be used to increase the specific capacity and other electrochemical performances of the regenerated positive electrode material by increasing the nickel content. In some embodiments, the "medium-low nickel" can be a positive electrode material with a nickel content of not more than 50%, and the "high nickel" can be a positive electrode material with a nickel content of not less than 80%.

[0036] For reference, the application proposes a recycling method of a positive electrode material in a waste lithium ion battery, which can include the following steps: preparing an organic nickel source shell layer on the surface of the waste positive electrode material to obtain a positive electrode material precursor; mixing the positive electrode material precursor with a lithium source and then sintering to obtain a regenerated positive electrode material.

[0037] The waste positive electrode material can be obtained by, for example, disassembling and separating the waste battery bag to obtain a positive electrode sheet, then calcining the positive electrode sheet to make the powder fall off from the current collector, collecting the powder, and then grinding and sieving to obtain a waste positive electrode material powder.

[0038] Exemplarily, the calcination temperature can be 550°C, and the calcination time can be 1h-4h.

[0039] In some embodiments, the waste positive electrode material can exemplarily but non-limitingly include at least one of a waste lithium nickel cobalt manganese oxide positive electrode material, a waste lithium nickel cobalt aluminum oxide positive electrode material, and a waste lithium cobalt oxide positive electrode material.

[0040] In some embodiments, the above waste positive electrode material can be a layered structure.

[0041] In some embodiments, the above-mentioned waste positive electrode material can be a single crystal structure, and the average particle size thereof can be 4-6 μm, such as 4 μm, 4.5 μm, 5 μm, 5.5 μm or 6 μm, etc. In some other embodiments, the waste positive electrode material can also not be excluded from being a polycrystalline structure. However, the waste positive electrode material in a single crystal structure is more obvious than the waste positive electrode material in a polycrystalline structure in terms of specific capacity, etc. after the method provided by the present application is adopted, and the reason can be that the coating material can be in close contact with each position of the particle when the single crystal structure is coated in a liquid phase, so that the particle can be uniformly coated in each position; and the contact position of the polycrystalline structure is more difficult to effectively contact with the coating material, so that the coating effect of these positions is poor.

[0042] In the present application, the organic nickel source shell layer is a Ni-MOF material with a metal organic framework structure.

[0043] Compared with inorganic nickel sources, the Ni-MOF material is easier to deposit on the surface layer of the particle when the Ni-MOF material is used as a Ni source, so as to realize uniform coating of the Ni-MOF.

[0044] In some embodiments, the preparation of the organic nickel source shell layer can include: mixing the waste positive electrode material and the preparation raw material of the organic nickel source shell layer, and then performing a hydrothermal reaction.

[0045] The preparation raw material includes a nickel salt, an organic ligand and an organic solvent.

[0046] Specifically, the nickel salt and the organic ligand can be dissolved in the organic solvent to form a mixed solution, and then the waste positive electrode material can be dispersed in the mixed solution, stirred for 20-60 min, and then transferred to a hydrothermal reaction kettle for hydrothermal reaction.

[0047] The nickel salt exemplarily but not limitatively can include at least one of Ni(NO3)2, NiCl2, Ni(CH3COO)2 and Ni(SO4)2.

[0048] The organic ligand exemplarily but not limitatively can include at least one of terephthalic acid, phthalic acid, 2,5-dihydroxyterephthalic acid and trimesic acid.

[0049] The organic solvent exemplarily but not limitatively can include N,N-dimethylformamide (DMF).

[0050] The above-mentioned dosage relationship between the ligand and nickel can refer to: two carboxylate groups match one Ni in terms of carboxylate groups contained in the ligand 2+ .

[0051] In some embodiments, the hydrothermal reaction can be performed at 120-180°C (e.g., 120°C, 130°C, 140°C, 150°C, 160°C, 170°C or 180°C, etc.) for 8-16 hours (e.g., 8 hours, 10 hours, 12 hours, 14 hours or 16 hours, etc.).

[0052] Through the above hydrothermal reaction, a Ni-MOF shell can be formed on the surface of the waste positive electrode material.

[0053] In some embodiments, the lithium source can exemplarily but non-limitingly include at least one of LiOH, Li2CO3, LiNO3 and CH3COOLi.

[0054] The total amount of lithium contained in the lithium source added newly and the lithium contained in the waste positive electrode material is 1.03-1.08 times (in terms of molar amount) of the total amount of transition metals in the positive electrode material precursor.

[0055] The sintering includes a first sintering stage and a second sintering stage. The first sintering stage can be performed at 450-550°C (e.g., 450°C, 480°C, 500°C, 520°C or 550°C, etc.) for 4-5 hours (e.g., 4 hours, 4.5 hours or 5 hours, etc.), and the second sintering stage can be performed at 750-900°C (e.g., 750°C, 780°C, 800°C, 820°C, 850°C, 880°C or 900°C, etc.) for 8-15 hours (e.g., 8 hours, 10 hours, 12 hours or 15 hours, etc.), and then cooled to 200-220°C (e.g., 200°C, 205°C, 210°C, 215°C or 220°C, etc.).

[0056] The heating rate and the cooling rate in the above sintering process can both be 1-12°C / min (e.g., 1°C / min, 2°C / min, 3°C / min, 4°C / min, 5°C / min, 6°C / min, 7°C / min, 8°C / min, 9°C / min, 10°C / min, 11°C / min or 12°C / min, etc.). In some preferable embodiments, the heating rate and the cooling rate in the sintering process can both be 5-10°C / min.

[0057] The above sintering can be performed in an oxygen-containing atmosphere. Exemplarily, the sintering can be performed at an oxygen partial pressure of 0.01-1 standard atmosphere, for example, the oxygen partial pressure during sintering can be 0.02, 0.06, 0.08, 0.1, 0.2, 0.4 or 0.8 standard atmosphere, etc.

[0058] After cooling to 200-220°C, cooling to room temperature, and then grinding and sieving.

[0059] In conclusion, the present application uses a liquid phase method to prepare a precursor in which a nickel source is coated on the surface of the waste positive electrode particles. Compared with the process of directly adding nickel oxide or hydroxide for high-temperature solid-phase nickel supplementation, the nickel source is more easily in close contact with the waste positive electrode particles, and the nickel element is more easily diffused into the waste positive electrode material, the nickel is more evenly dispersed, and the electrochemical performance is more excellent. In the traditional solid-phase sintering nickel supplementation process, the contact area between the waste positive electrode material and the nickel source is smaller, the reactants have poor contact, and the high-nickel and low-nickel particles are difficult to diffuse uniformly, which is not conducive to the diffusion of nickel, resulting in poor electrochemical performance. Moreover, the present application uses Ni-MOF as the Ni source. In the hydrothermal reaction process, Ni-MOF is more easily complexed on the surface of the particles to form a uniform nickel source shell layer compared with inorganic nickel sources. In the subsequent high-temperature treatment process, there are more nickel diffusion channels, which are more conducive to uniform dispersion. In addition, compared with the traditional pyrometallurgical and hydrometallurgical recovery methods, the method provided by the present application has the advantages of simple process, low cost, environmental friendliness, and reusability after regeneration.

[0060] Correspondingly, the present application provides a regenerated positive electrode material, which is obtained by treating the waste positive electrode material by the recycling method of any one of the preceding embodiments.

[0061] The regenerated positive electrode material has a higher nickel content than the waste positive electrode material, and has higher specific capacity and other electrochemical properties.

[0062] The features and performance of the present application are further described in detail below in conjunction with examples.

[0063] Example 1

[0064] The present embodiment provides a recycling method for positive electrode materials in waste lithium-ion batteries, which comprises the following steps:

[0065] S1: Disassemble the waste battery bag containing NCM111 (LiNi 0.33 Co 0.33 Mn 0.33 O2) positive electrode material under an inert atmosphere, and obtain the positive electrode sheet by separation.

[0066] S2: Calcine the positive electrode sheet at 550℃ for 2h to make the powder fall off from the current collector, collect the powder, and then grind and sieve (400 mesh) to obtain a waste positive electrode material powder (waste NCM111 powder, the SEM image of which is shown in Figure 1 .

[0067] S3: 0.027 mol of Ni(NO3)2and 0.027 mol of BDC were dispersed in 30 ml of DMF solution and stirred uniformly to obtain a mixed solution. 0.1 mol of waste NCM111 powder was added to the above mixed solution and stirred for 20 min, and then transferred into a polytetrafluoroethylene hydrothermal reaction kettle. After being kept at 120℃ for 16 h, the Ni-MOF coated waste NCM111 precursor was obtained by filtration, washing and drying.

[0068] S4: The above positive electrode material precursor was mixed with Li2CO3(excess 3%) and then transferred into an oxygen atmosphere furnace. Under the condition of oxygen partial pressure of 0.01 standard atmosphere, the temperature was increased to 450℃ at a rate of 10℃ / min and kept for 4 h, and then increased to 900℃ at a rate of 10℃ / min and kept for 8 h. Subsequently, the temperature was decreased to 300℃ at a rate of 10℃ / min, and after cooling to room temperature, the R-NCM622(LiNi 0.6 Co 0.2 Mn 0.2 O2) regenerated positive electrode material (the SEM image of the regenerated positive electrode material is shown in FIG. 6, and "R" in "R-NCM622" means "regenerated", the same below). Figure 2

[0069] Example 2

[0070] The present embodiment provides a method for recycling positive electrode material in waste lithium ion battery, comprising the following steps:

[0071] S1: The waste battery bag containing NCM111(LiNi 0.33 Co 0.33 Mn 0.33 O2) positive electrode material was disassembled under inert atmosphere, and the positive electrode sheet was obtained by separation.

[0072] S2: The positive electrode sheet was calcined at 550℃ for 2 h to make the powder fall off from the current collector. After collecting the powder, the powder was ground and sieved (400 mesh) to obtain waste positive electrode material powder (waste NCM111 powder).

[0073] S3: 0.047 mol of NiCl2and 0.047 mol of BDC were dispersed in 50 ml of DMF solution and stirred uniformly to obtain a mixed solution. 0.1 mol of waste NCM111 powder was added to the above mixed solution and stirred for 60 min, and then transferred into a polytetrafluoroethylene hydrothermal reaction kettle. After being kept at 180℃ for 8 h, the Ni-MOF coated waste NCM111 precursor was obtained by filtration, washing and drying.

[0074] ​S4: The above positive electrode material precursor is mixed with LiOH (8% excess) uniformly, and then transferred into an oxygen atmosphere furnace. Under the condition of 1 standard atmosphere of oxygen partial pressure, the temperature is raised to 550°C at a rate of 5°C / min, and then kept for 4h. Then the temperature is raised to 850°C at a rate of 5°C / min, and then kept for 15h. Subsequently, the temperature is reduced to 300°C at a rate of 5°C / min. After cooling to room temperature, grinding and sieving are performed to obtain R-NCM811 (LiNi 0.8 Co 0.1 Mn 0.1 O2) regenerated positive electrode material.

[0075] Example 3

[0076] The present embodiment provides a method for recycling positive electrode material in a waste lithium ion battery, comprising the following steps:

[0077] S1: The waste battery bag containing NCM523 (LiNi 0.5 Co 0.2 Mn 0.3 O2) positive electrode material is disassembled under inert atmosphere, and the positive electrode sheet is obtained by separation.

[0078] S2: The positive electrode sheet is calcined at 550°C for 2h, so that the powder falls off from the current collector. After collecting the powder, grinding and sieving (400 mesh) are performed to obtain waste positive electrode material powder (waste NCM523 powder).

[0079] S3: 0.04mol Ni(SO4)2 and 0.04mol BDC are dispersed in 40ml DMF solution and stirred uniformly to obtain a mixed solution. Then 0.1mol waste NCM523 powder is added to the above mixed solution and stirred for 40min. Then it is transferred into a polytetrafluoroethylene hydrothermal reaction kettle and kept at 150°C for 12h. After filtration, washing and drying, a Ni-MOF coated waste NCM523 precursor is obtained.

[0080] S4: The above positive electrode material precursor is mixed with LiOH (5% excess) uniformly, and then transferred into an oxygen atmosphere furnace. Under the condition of 1 standard atmosphere of oxygen partial pressure, the temperature is raised to 500°C at a rate of 5°C / min, and then kept for 5h. Then the temperature is raised to 750°C at a rate of 5°C / min, and then kept for 12h. Subsequently, the temperature is reduced to 300°C at a rate of 5°C / min. After cooling to room temperature, grinding and sieving are performed to obtain R-NCM90 (LiNi 0.9 Co 0.4 Mn 0.6 O2) regenerated positive electrode material.

[0081] Comparative Example 1

[0082] The present comparative example provides a method for recycling positive electrode material in a waste lithium ion battery, comprising the following steps:

[0083] S1: The waste battery bag containing NCM111 (LiNi 0.33 Co 0.33 Mn 0.33 O2) cathode material was disassembled under inert atmosphere, and the cathode sheet was obtained by separation.

[0084] S2: The cathode sheet was calcined at 550°C for 2h, so that the powder fell off from the current collector. After collecting the powder, it was ground and sieved (400 mesh) to obtain the waste cathode material powder (waste NCM111 powder).

[0085] S3: 0.1 mol of waste NCM111 powder was uniformly mixed with 0.27 mol of NiO, Li2CO3 (excess 3%), and then transferred into an oxygen atmosphere furnace. Under the condition of oxygen partial pressure of 1 standard atmosphere, it was heated to 450°C at a rate of 10°C / min, and then heated to 900°C at a rate of 10°C / min for 8h. Subsequently, it was cooled to 300°C at a rate of 10°C / min, and then ground and sieved after cooling to room temperature to obtain R-NCM622 (LiNi 0.6 Co 0.2 Mn 0.2 O2) regenerated cathode material (SEM image thereof is shown in Figure 3 ).

[0086] Comparative Example 2

[0087] This comparative example provides a method for recycling the cathode material in a waste lithium ion battery, comprising the following steps:

[0088] S1: The waste battery bag containing NCM111 (LiNi 0.33 Co 0.33 Mn 0.33 O2) cathode material was disassembled under inert atmosphere, and the cathode sheet was obtained by separation.

[0089] S2: The cathode sheet was calcined at 550°C for 2h, so that the powder fell off from the current collector. After collecting the powder, it was ground and sieved (400 mesh) to obtain the waste cathode material powder (waste NCM111 powder).

[0090] S3: 0.1 mol of waste NCM111 powder was uniformly mixed with 0.027 mol of Ni(OH)2, LiOH (excess 8%), and then transferred into an oxygen atmosphere furnace. Under the condition of oxygen partial pressure of 1 standard atmosphere, it was heated to 550°C at a rate of 5°C / min, and then heated to 850°C at a rate of 5°C / min for 15h. Subsequently, it was cooled to 300°C at a rate of 5°C / min, and then ground and sieved after cooling to room temperature to obtain R-NCM811 (LiNi 0.8 Co 0.1 Mn0.1 O2) regenerating the positive electrode material.

[0091] Test Examples

[0092] The regenerated positive electrode materials obtained in Examples 1-3 and Comparative Examples 1-2 were weighed with a conductive agent (Super P) and a binder (PVDF dissolved in NMP at a mass fraction of 5%) at a mass ratio of 90:5:5 in a stirring box; the stirring box was placed in a homogenizer with a set program to mix the materials, and then the materials were uniformly coated on a 16 μm aluminum foil by a coating machine, with a coating thickness controlled at 0.25 mm. After drying, cutting, weighing and extruding, a positive electrode sheet with a diameter of 14 mm was obtained. A metal lithium was used as a negative electrode, and a CR2032 button cell was assembled using LiPF6 / EC / EMC electrolyte and a PE separator.

[0093] After the button cell was placed for 10 h, it was placed on a blue light tester (CT2001C) to test the charge-discharge cycle performance. The test conditions were set as follows: 25℃, 2.8 V-4.3 V, 0.1C / 0.1C cycle for 3 weeks to activate the button cell, and then 1C / 1C cycle for 200 weeks to investigate the specific capacity and cycle performance of the positive electrode material. The results are shown in Table 1.

[0094] Table 1 Performance test results

[0095]

[0096]

[0097] As can be seen from Table 1, the regenerated positive electrode material obtained by the method provided by the application has better 0.1C initial discharge capacity, 0.1C initial charge-discharge efficiency and cycle performance. It is shown that the method provided by the application can effectively realize the recycling of waste positive electrode materials.

[0098] In summary, the recycling method provided by the application is simple, low in cost and environmentally friendly, and can regenerate the waste positive electrode material to obtain a regenerated positive electrode material that can be reused. The method uses a mode of first preparing an organic nickel source shell layer on the surface of the waste positive electrode material, and then performing lithium supplement sintering. Compared with directly adding an oxide or hydroxide of nickel in the nickel supplement process, the nickel source can be more uniformly dispersed on the surface of the waste positive electrode material, a larger contact area is obtained, and the nickel source and the waste positive electrode material are more closely contacted, and the regenerated positive electrode material obtained has better electrochemical performance.

[0099] The above merely describes the preferred embodiments of the present application, and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for recycling a cathode material, characterized by, The method comprises the following steps: preparing an organic nickel source shell layer on the surface of the waste positive electrode material to obtain a positive electrode material precursor; and mixing the positive electrode material precursor with a lithium source and then sintering to obtain a regenerated positive electrode material. The organic nickel source shell layer is a Ni-MOF material with a metal organic framework structure; the preparation of the organic nickel source shell layer comprises the following steps: mixing the waste positive electrode material with preparation raw materials of the organic nickel source shell layer and then performing a hydrothermal reaction; the preparation raw materials comprise a nickel salt, an organic ligand and an organic solvent; The waste positive electrode material has a layered structure. The hydrothermal reaction is performed at 120-180 DEG C for 8-16 hours. The sintering comprises a first sintering stage and a second sintering stage; the first sintering stage is performed at 450-550 DEG C for 4-5 hours, and the second sintering stage is performed at 750-900 DEG C for 8-15 hours, and then the temperature is decreased to 200-220 DEG C. The sintering is performed under an oxygen partial pressure of 0.01-1 atm.

2. The recycling method according to claim 1, characterized in that, The waste positive electrode material comprises at least one of waste nickel-cobalt-manganese lithium acid positive electrode material, waste nickel-cobalt-aluminum lithium acid positive electrode material and waste cobalt lithium acid positive electrode material.

3. The recycling method of claim 1, wherein, The nickel salt comprises at least one of Ni(NO3)2, NiCl2, Ni(CH3COO)2 and Ni(SO4)2; The organic ligand comprises at least one of terephthalic acid, phthalic acid, 2,5-dihydroxyterephthalic acid and trimesic acid; and / or the organic solvent comprises N,N-dimethylformamide. The lithium source comprises at least one of LiOH, Li2CO3, LiNO3 and CH3COOLi.

4. The recycling method of claim 1, wherein, The heating rate and the cooling rate of the sintering process are both 1-12 DEG C / min.

5. The recycling method of claim 1, wherein, The heating rate and the cooling rate of the sintering process are both 5-10 DEG C / min.

6. The recycling method according to claim 5, characterized in that, The regenerated positive electrode material is obtained by treating the waste positive electrode material by the recycling method according to any one of claims 1-6.

7. A regenerated cathode material, characterized in that, ​

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