Direct regeneration method and application of waste ternary lithium ion battery black powder

Abstract

The invention belongs to the technical field of electrochemical energy storage, and relates to a direct regeneration method of waste ternary lithium ion battery black powder, which comprises the following steps: 1, mixing LiNi0. 5Co0. 2Mn0. 3O2 black powder with a sodium hydroxide solution, magnetically stirring, reacting, centrifugally washing, drying and calcining to obtain a positive electrode material; 2, uniformly mixing the positive electrode material obtained in the step 1 with molten salt, and carrying out melting calcination treatment; 3, centrifugally washing and drying the positive electrode subjected to melting and calcining treatment in the step 2 by using deionized water; 4, lithium carbonate is added into the positive electrode obtained in the step 3 for high-temperature calcination, and a LiNi0. 5Co0. 2Mn0. 3O2 ternary positive electrode is obtained; the method has the characteristics of low cost, complete structure repair, excellent cycle performance and the like, and provides an effective solution for practical application of a waste lithium ion battery regeneration technology.

Description

Technical Field

[0001] The invention belongs to the technical field of electrochemical energy storage, and relates to a direct regeneration method for waste ternary lithium-ion battery black powder and an application thereof. Background Art

[0002] As the global energy structure accelerates its transformation towards clean energy, lithium-ion batteries have become the core energy storage unit for electric vehicle power systems and portable electronic devices due to their high energy density and cycle stability. 0.5 Co 0.2 Mn 0.3 O2 dominates the current power battery market due to its excellent cost-effectiveness and adjustable electrochemical properties, making its recycling a focus of industry attention. The current industrial recycling system is mainly based on two major technical routes: pyrometallurgy and hydrometallurgy.

[0003] However, while existing hydrometallurgy, which uses acid leaching and solvent extraction processes to efficiently separate metal elements, the use of highly corrosive reagents can easily lead to heavy metal wastewater pollution. Pyrometallurgy, which relies on high-temperature smelting above 1500°C to extract transition metal alloys, while simple, is accompanied by significant energy consumption and carbon dioxide emissions. Both of these traditional methods suffer from the drawback of downgrading valuable elements during resource recycling.

[0004] Therefore, a method is needed to solve the above technical problems by effectively restoring the structure of the battery positive electrode material and being suitable for commercial large-scale regeneration. Summary of the Invention

[0005] This invention restores the electrochemical performance of the cathode material while maintaining its crystalline integrity through lithium compensation and structural repair. This decomposition-free material regeneration method not only eliminates the tedious metal purification and resynthesis steps, but also reduces energy consumption by approximately 60% and carbon emissions by over 75% during the recycling process, offering a new solution for building a closed-loop battery industry chain.

[0006] The technical solution adopted by the present invention to solve the technical problem is: a direct regeneration method for waste ternary lithium-ion battery black powder, comprising the following steps:

[0007] Step 1: LiNi 0.5 Co 0.2 Mn 0.3 O2 black powder is mixed with sodium hydroxide solution and then magnetically stirred. After the reaction, it is centrifuged, washed and dried, and calcined to obtain the positive electrode material.

[0008] Step 2: Evenly mix the positive electrode material obtained in step 1 with the molten salt, and perform melt calcination;

[0009] Step 3: centrifugally washing and drying the positive electrode after the melt calcination treatment in step 2 with deionized water;

[0010] Step 4: Add lithium carbonate to the positive electrode obtained in step 3 and calcine at high temperature to obtain LiNi 0.5 Co 0.2 Mn 0.3 O2 ternary positive electrode.

[0011] Preferably, in step 1, the concentration of the sodium hydroxide solution is 1 to 5 mol / L; the amount of the sodium hydroxide solution is per gram of LiNi 0.5 Co 0.2 Mn 0.3 O2 black powder uses 10 to 30 ml of sodium hydroxide solution; the stirring speed of the magnetic stirring is 300 to 600 r / min, and the stirring time of the magnetic stirring is 15 to 30 minutes.

[0012] Preferably, in the step 1, the calcination temperature is 350-450° C., and the calcination is kept warm for 1-3 hours.

[0013] Preferably, in step 2, the molten salt includes any two of sodium chloride, sodium sulfate, and sodium fluoride.

[0014] More preferably, when the molten salt is sodium chloride or sodium sulfate, the molar ratio of sodium chloride to sodium sulfate is 1:1 to 2:1.

[0015] More preferably, the molar ratio of the molten salt to the positive electrode material is 1:1 to 2:1.

[0016] More preferably, the calcination temperature of the melt calcination treatment is 650-750° C., and the holding time is 4-8 hours.

[0017] More preferably, in step 4, the molar ratio of the positive electrode to the lithium carbonate is 1:1 to 2:1.

[0018] Preferably, in the step 4, the calcination temperature of the high-temperature calcination is 700-900° C., and the holding time is 4-8 hours.

[0019] The present invention also provides an application of a regenerated positive electrode material, wherein the positive electrode material is prepared by the above-mentioned direct regeneration method, and the regenerated positive electrode material is used for assembling a lithium-ion battery.

[0020] The beneficial effects of the present invention are:

[0021] 1. The present invention is applicable to waste LiNi 0.5 Co 0.2 Mn 0.3 O2 lithium-ion battery positive electrode material regeneration can effectively restore the battery positive electrode material structure.

[0022] 2. The present invention selects a suitable molten salt system, optimizes calcination conditions, and uses sodium chloride-sodium sulfate as the molten sodium salt system to introduce Na atoms into the unoccupied tetrahedral sites of the near-surface rock salt phase of the waste positive electrode, thereby achieving a directional transformation from the near-surface rock salt phase structure to a layered structure.

[0023] 3. The low cost and low melting point of the lithium carbonate of the present invention can be used as a lithium supplement, and at a suitable ratio and temperature, it can effectively supplement the lithium vacancies of the waste positive electrode and achieve complete regeneration of the waste positive electrode.

[0024] 4. The molten salt system formula of the present invention is economical and reasonable, and the selected raw materials have high commercial feasibility and large-scale application potential.

[0025] 5. The battery assembled by the present invention has a high initial specific capacity and cycle stability, and is suitable for the practical application needs of large-scale regeneration of commercial black powder. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a charge-discharge curve diagram of the first three cycles of the lithium-ion battery in Example 1 of a method for directly regenerating black powder from waste ternary lithium-ion batteries of the present invention;

[0027] Figure 2 Graph showing the cycling performance of lithium-ion batteries in Examples 1, 2, 3, and 4 of the present invention and Comparative Example 1 at a rate of 0.5C. DETAILED DESCRIPTION

[0028] The following will provide a clear and complete description of the relevant technologies in the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0029] like Figures 1-2 As shown, the direct regeneration method of waste ternary lithium-ion battery black powder in this embodiment includes the following steps:

[0030] Step 1: Use waste LiNi 0.5 Co 0.2 Mn 0.3 O2 black powder is mixed with sodium hydroxide solution, stirred in a magnetic stirrer, centrifuged and washed after the reaction, dried, and calcined to obtain waste positive electrode material;

[0031] Step 2: Mix the waste positive electrode with a suitable molten salt, place it in a muffle furnace, and calcine it at the melting temperature;

[0032] Step 3: The positive electrode treated with the molten salt is centrifuged and washed with deionized water to obtain a one-step treated waste positive electrode;

[0033] Step 4: Add lithium carbonate to the positive electrode after the step treatment and place it in a muffle furnace for high-temperature calcination to obtain the regenerated LiNi 0.5 Co 0.2 Mn 0.3 O2 ternary positive electrode.

[0034] Wherein, the molten salt system is a mixture of sodium chloride and sodium sulfate.

[0035] Sodium hydroxide solution is used to remove aluminum foil from black powder, and high-temperature calcination process is used to remove organic impurities such as PVDF.

[0036] Furthermore, in step 1, the concentration of the sodium hydroxide solution is 1-5 mol / L; the dosage is 10-30 ml of sodium hydroxide solution per gram of black powder positive electrode; the stirring speed is 300-600 r / min, and the stirring time is 15-30 min.

[0037] Furthermore, the dried black powder is placed in a square alumina magnetic boat and calcined at 650-750° C. for 4-8 hours.

[0038] The sodium salt system, with sodium ions as the sole cationic component, exhibits unique site-selectivity in its molten-state ion transport mechanism. This sodium salt system offers both economical efficiency and process compatibility: raw material costs are lower than those of mainstream lithium salt systems, and melt processing temperatures are highly compatible with existing cathode material sintering processes, enabling large-scale production without the need for specialized equipment.

[0039] Furthermore, the sodium salt system is any two of sodium chloride, sodium sulfate, and sodium fluoride.

[0040] Furthermore, when the molten salt is sodium chloride or sodium sulfate, the molar ratio of sodium chloride to sodium sulfate is 1:1 to 2:1.

[0041] Furthermore, in step 2, the molar ratio of the waste positive electrode to the molten salt is 1:1 to 2:1.

[0042] Furthermore, the uniformly mixed materials are placed in a square alumina magnetic boat, and the melting heat treatment temperature is 650° C. to 750° C.; and the heat preservation time is 4 to 8 hours.

[0043] Lithium carbonate has a low melting point, so lithium carbonate is used as a lithium source for high-temperature lithium replenishment. At the same time, the amount of lithium replenishment and the calcination temperature must be controlled. Excessive lithium content will lead to residual impurities on the surface, and too high a temperature will cause internal structure damage, affecting the electrochemical performance.

[0044] Furthermore, the ratio of the positive electrode to the lithium carbonate treated once in step 4 is 1:1 to 2:1.

[0045] Furthermore, after being uniformly mixed, the mixture is placed in a square alumina magnetic boat and calcined in a muffle furnace at a temperature of 800-900° C. for a holding time of 4-8 hours.

[0046] The present invention designs a molten sodium salt system for direct regeneration. The molten salt pretreatment introduces Na atoms into the unoccupied tetrahedral sites of the rock salt phase near the surface of the spent positive electrode, changes the electronic state distribution of the bridging oxygen anions, reduces the superexchange interaction between Ni-O-Ni in the rock salt phase, and induces the directional transformation of the rock salt phase to a layered structure under high temperature conditions. Therefore, the subsequent high-temperature lithium replenishment process Li + The migration pathway of lithium vacancies is transformed from a high-energy route to a more favorable low-barrier route, thereby achieving efficient replenishment of lithium vacancies.

[0047] The present invention provides a waste LiNi based on a short process 0.5 Co 0.2 Mn 0.3 A method for regenerating O2 lithium-ion battery black powder. Unlike traditional hydrometallurgical recycling strategies, this technology uses molten sodium salt treatment to create a closed-loop regeneration pathway from waste black powder to regenerated cathode material, achieving structural reconstruction of the near-surface rock salt phase in the ternary cathode material and restoring the material's performance.

[0048] The regenerated positive electrode prepared by the method of the present invention is assembled into a half-cell with a lithium metal negative electrode. When the regenerated positive electrode material is operated in a voltage range of 2.5 to 4.3 V, the gram capacity (≥155 mAh g -1 Key performance indicators such as battery life (capacity retention > 80% after 200 cycles) have reached commercial-grade cathode material standards, significantly outperforming products from existing recycling processes. This provides an industrially feasible technical solution for building a sustainable circular economy system for power batteries.

[0049] Example

[0050] This example achieves direct regeneration of spent ternary cathodes under mild and simple conditions by optimizing the molten salt type, calcination temperature, and holding time. To test the effectiveness of the proposed regeneration method in lithium-ion batteries, a half-cell was assembled with a lithium sheet negative electrode. The lithium half-cells in the following examples were assembled in an argon atmosphere glove box with a moisture and oxygen content of less than 0.1 ppm. The model was a CR2032 button cell. After assembly, the cells were left for 3 to 6 hours and then tested on a CT-4008Tn battery test system provided by Newway Co., Ltd. The voltage range was 2.5 to 4.3 V, and constant current charge and discharge tests were performed at a current density of 0.5 C.

[0051] Example 1

[0052] This embodiment provides a method for recovering and regenerating positive electrode materials from waste ternary lithium-ion battery black powder, comprising the following steps:

[0053] Step 1: 2g of waste LiNi 0.5 Co 0.2 Mn 0.3 The O2 black powder was mixed with 20 ml of a 1 mol / L sodium hydroxide solution, stirred in a magnetic stirrer for 15 min, centrifuged and washed and dried after the reaction, and kept at 400° C. in a muffle furnace for 2 h to obtain the waste positive electrode material.

[0054] Step 2: Mix the waste positive electrode and molten salt evenly, place them in a muffle furnace, and keep them warm at a melting temperature of 650°C for 4 hours.

[0055] Step 3: The positive electrode treated with the molten salt is centrifuged and washed with deionized water to obtain a one-step treated waste positive electrode;

[0056] Step 4: Add lithium carbonate to the positive electrode after the step treatment and place it in a muffle furnace, keep it at 850 ° C for 6 hours to obtain the regenerated LiNi 0.5 Co 0.2 Mn 0.3 O2 ternary positive electrode.

[0057] The molten salt is a mixture of sodium chloride and sodium sulfate in a molar ratio of 1:1, and the molar ratio of the waste positive electrode to the molten salt is 1:1. The molar ratio of the positive electrode after one-step treatment to lithium carbonate is 1:1.

[0058] The regenerated positive electrode and lithium metal negative electrode were assembled into a CR2032 button cell in an argon-filled glove box and the electrochemical performance was tested. Figure 1 、 Figure 2 As shown, the discharge capacity of the assembled battery at 0.5C rate at room temperature is 155.5 mAh g -1 , the capacity retention rate was 80.6% after 200 cycles at 0.5C.

[0059] Example 2

[0060] This embodiment provides a method for recovering and regenerating positive electrode materials from waste ternary lithium-ion battery black powder, comprising the following steps:

[0061] Step 1: 2g of waste LiNi 0.5 Co 0.2 Mn 0.3The O2 black powder was mixed with 20 ml of a 1 mol / L sodium hydroxide solution, stirred in a magnetic stirrer for 15 min, centrifuged and washed and dried after the reaction, and kept at 400° C. in a muffle furnace for 2 h to obtain the waste positive electrode material.

[0062] Step 2: Mix the waste positive electrode and molten salt evenly, place them in a muffle furnace, and keep them warm at a melting temperature of 700°C for 4 hours.

[0063] Step 3: The positive electrode treated with the molten salt is centrifuged and washed with deionized water to obtain a one-step treated waste positive electrode;

[0064] Step 4: Add lithium carbonate to the positive electrode after the step treatment and place it in a muffle furnace, keep it at 850 ° C for 6 hours to obtain the regenerated LiNi 0.5 Co 0.2 Mn 0.3 O2 ternary positive electrode.

[0065] The molten salt is a mixture of sodium chloride and sodium sulfate in a molar ratio of 1:1, and the molar ratio of the waste positive electrode to the molten salt is 1:1. The molar ratio of the positive electrode after one-step treatment to lithium carbonate is 1:1.

[0066] The regenerated positive electrode and lithium metal negative electrode were assembled into a CR2032 button cell in an argon-filled glove box and the electrochemical performance was tested. Figure 1 、 Figure 2 As shown in the figure, the discharge capacity of the assembled battery at a rate of 0.5C at room temperature is 143.4 mAh g -1 , the capacity retention rate was 71.7% after 200 cycles at 0.5C.

[0067] Example 3

[0068] This embodiment provides a method for recovering and regenerating positive electrode materials from waste ternary lithium-ion battery black powder, comprising the following steps:

[0069] Step 1: 2g of waste LiNi 0.5 Co 0.2 Mn 0.3 The O2 black powder was mixed with 20 ml of a 1 mol / L sodium hydroxide solution, stirred in a magnetic stirrer for 15 min, centrifuged and washed and dried after the reaction, and kept at 400° C. in a muffle furnace for 2 h to obtain the waste positive electrode material.

[0070] Step 2: Mix the waste positive electrode and molten salt evenly, place them in a muffle furnace, and keep them warm at a melting temperature of 650°C for 4 hours.

[0071] Step 3: The positive electrode treated with the molten salt is centrifuged and washed with deionized water to obtain a one-step treated waste positive electrode;

[0072] Step 4: Add lithium carbonate to the positive electrode after the step treatment and place it in a muffle furnace, keep it at 800℃ for 6h to obtain the regenerated LiNi 0.5 Co 0.2 Mn 0.3 O2 ternary positive electrode.

[0073] The molten salt is a mixture of sodium chloride and sodium sulfate in a molar ratio of 1:1, and the molar ratio of the waste positive electrode to the molten salt is 1:1. The molar ratio of the positive electrode after one-step treatment to lithium carbonate is 1:1.

[0074] The regenerated positive electrode and lithium metal negative electrode were assembled into a CR2032 button cell in an argon-filled glove box and the electrochemical performance was tested. Figure 1 、 Figure 2 As shown in the figure, the discharge capacity of the assembled battery at a rate of 0.5C at room temperature is 130.6 mAh g -1 , the capacity retention rate was 79.5% after 200 cycles at 0.5C.

[0075] Example 4

[0076] This embodiment provides a method for recovering and regenerating positive electrode materials from waste ternary lithium-ion battery black powder, comprising the following steps:

[0077] Step 1: 2g of waste LiNi 0.5 Co 0.2 Mn 0.3 The O2 black powder was mixed with 20 ml of a 1 mol / L sodium hydroxide solution, stirred in a magnetic stirrer for 15 min, centrifuged and washed and dried after the reaction, and kept at 400° C. in a muffle furnace for 2 h to obtain the waste positive electrode material.

[0078] Step 2: Mix the waste positive electrode and molten salt evenly, place them in a muffle furnace, and keep them warm at a melting temperature of 650°C for 4 hours.

[0079] Step 3: The positive electrode treated with the molten salt is centrifuged and washed with deionized water to obtain a one-step treated waste positive electrode;

[0080] Step 4: Add lithium carbonate to the positive electrode after the first step of treatment and place it in a muffle furnace, keep it at 900℃ for 6h to obtain the regenerated LiNi 0.5 Co 0.2 Mn 0.3 O2 ternary positive electrode.

[0081] The molten salt is a mixture of sodium chloride and sodium sulfate in a molar ratio of 1:1, and the molar ratio of the waste positive electrode to the molten salt is 1:1. The molar ratio of the positive electrode after one-step treatment to lithium carbonate is 1:1.

[0082] The regenerated positive electrode and lithium metal negative electrode were assembled into a CR2032 button cell in an argon-filled glove box and the electrochemical performance was tested. Figure 1 、 Figure 2 As shown in the figure, the discharge capacity of the assembled battery at a rate of 0.5C at room temperature is 135.3 mAh g -1 , the capacity retention rate was 61.2% after 200 cycles at 0.5C.

[0083] Comparative Example 1

[0084] This embodiment provides a method for recovering and regenerating positive electrode materials from waste ternary lithium-ion battery black powder, comprising the following steps:

[0085] Step 1: 2g of waste LiNi 0.5 Co 0.2 Mn 0.3 The O2 black powder was mixed with 20 ml of a 1 mol / L sodium hydroxide solution, stirred in a magnetic stirrer for 15 min, centrifuged and washed and dried after the reaction, and kept at 400° C. in a muffle furnace for 2 h to obtain the waste positive electrode material.

[0086] Step 2: Mix the waste positive electrode and molten salt evenly, place them in a muffle furnace, and keep them warm at a melting temperature of 650°C for 4 hours.

[0087] Step 3: The positive electrode treated with the molten salt is centrifuged and washed with deionized water to obtain a one-step treated waste positive electrode;

[0088] Step 4: Add lithium carbonate to the positive electrode after the step treatment and place it in a muffle furnace, keep it at 850 ° C for 6 hours to obtain the regenerated LiNi 0.5 Co 0.2 Mn 0.3 O2 ternary positive electrode.

[0089] The molten salt is a mixture of sodium fluoride and sodium chloride with a molar ratio of 1:2, and the molar ratio of the waste positive electrode to the molten salt is 1:1. The molar ratio of the positive electrode after one-step treatment to lithium carbonate is 1:1.

[0090] The regenerated positive electrode and lithium metal negative electrode were assembled into a CR2032 button cell in an argon-filled glove box and the electrochemical performance was tested. Figure 1 、 Figure 2 As shown in the figure, the discharge capacity of the assembled battery at a rate of 0.5C at room temperature is 138.2 mAh g -1 The capacity retention rate after 200 cycles at 0.5C is 87.1%. Table 1 shows the performance test results of the lithium-ion battery.

[0091] Table 1

[0092] Group <![CDATA[0.5C initial capacity (mAh g -1 )]]> Cycle retention rate Example 1 155.5 80.6% (200 laps) Example 2 143.4 71.7% (200 laps) Example 3 130.6 79.5% (200 laps) Example 4 135.3 61.2% (200 laps) Comparative Example 1 138.2 87.1% (200 laps)

[0093] From the results in Table 1, it can be seen that compared with Comparative Example 1, the discharge capacity of the lithium ion battery provided by the present invention reaches 155 mAh g at a voltage of 2.5-4.3 V. -1 After 200 cycles under working conditions, the capacity retention rate is higher than 80%, showing good electrochemical stability. This performance advantage is attributed to the sodium chloride-sodium sulfate molten salt system, which introduces Na atoms into the tetrahedral sites of the rock salt phase, changes the electronic distribution of the bridging oxygen anions, reduces the magnetic moment of the Ni element, and thus weakens the linear superexchange interaction, ultimately promoting the hindrance of Li + The transported rock salt structure is transformed into a layered structure, providing new ideas for the regeneration of waste ternary lithium-ion batteries.

[0094] In summary, the battery black powder regeneration method of the present invention has the characteristics of low cost, complete structural repair, and excellent cycle performance, and provides an effective solution for the practical application of waste lithium-ion battery regeneration technology.

[0095] It should be emphasized that the above are only preferred embodiments of the present invention and do not limit the present invention in any form. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A direct regeneration method for waste ternary lithium-ion battery black powder, characterized in that: The following steps are involved: Step 1: LiNi 0.5 Co 0.2 Mn 0.3 O2 black powder is mixed with sodium hydroxide solution and then magnetically stirred. After the reaction, it is centrifuged, washed and dried, and calcined to obtain the positive electrode material. Step 2: Evenly mix the positive electrode material obtained in step 1 with the molten salt, and perform melt calcination; Step 3: centrifugally washing and drying the positive electrode after the melt calcination treatment in step 2 with deionized water; Step 4: Add lithium carbonate to the positive electrode obtained in step 3 and calcine at high temperature to obtain LiNi 0.5 Co 0.2 Mn 0.3 O2 ternary positive electrode.

2. The direct regeneration method of waste ternary lithium ion battery black powder according to claim 1, characterized in that: In the step 1, the concentration of the sodium hydroxide solution is 1-5 mol / L; the amount of the sodium hydroxide solution is per gram of LiNi 0.5 Co 0.2 Mn 0.3 O2 black powder uses 10-30 ml of sodium hydroxide solution; the stirring speed of the magnetic stirring is 300-600 r / min, and the stirring time of the magnetic stirring is 15-30 min.

3. The direct regeneration method of waste ternary lithium ion battery black powder according to claim 1, characterized in that: In the step 1, the calcination temperature is 350-450° C., and the calcination is kept warm for 1-3 hours.

4. The direct regeneration method of waste ternary lithium ion battery black powder according to claim 1, characterized in that: In the step 2, the molten salt includes any two of sodium chloride, sodium sulfate, and sodium fluoride.

5. The direct regeneration method of waste ternary lithium ion battery black powder according to claim 4, characterized in that: When the molten salt is sodium chloride or sodium sulfate, the molar ratio of sodium chloride to sodium sulfate is 1:1 to 2:

1.

6. The direct regeneration method for waste ternary lithium-ion battery black powder according to claim 4, characterized in that: The molar ratio of the molten salt to the positive electrode material is 1:1 to 2:

1.

7. The direct regeneration method for waste ternary lithium-ion battery black powder according to claim 4, characterized in that: The calcination temperature of the melt calcination treatment is 650-750° C., and the holding time is 4-8 hours.

8. The method for directly regenerating black powder from waste ternary lithium-ion batteries according to claim 1, characterized in that: In the step 4, the molar ratio of the positive electrode to lithium carbonate is 1:1 to 2:

1.

9. The method for directly regenerating black powder from waste ternary lithium-ion batteries according to claim 1, characterized in that: In the step 4, the calcination temperature of the high-temperature calcination is 700-900° C., and the holding time is 4-8 hours.

10. An application of a regenerated positive electrode material, characterized in that: The positive electrode material is prepared by the direct regeneration method according to any one of claims 1 to 9, and the regenerated positive electrode material is used to assemble a lithium-ion battery.

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