A direct regeneration and repair process for failed lithium nickel cobalt manganese oxide cathode material and its application

Abstract

The present invention discloses a direct regeneration and repair process for failed lithium nickel-cobalt-manganese oxide cathode materials and its application. The direct regeneration and repair process comprises the steps of preliminary treatment of the failed lithium nickel-cobalt-manganese oxide cathode materials, impurity removal pretreatment, material mixing, and high-temperature calcination. The direct regeneration and repair process for failed lithium nickel-cobalt-manganese oxide cathode materials of the present invention is characterized by simple operation, a short process flow, and high safety. The directly regenerated and repaired lithium nickel-cobalt-manganese oxide cathode materials have excellent electrochemical and cycling properties, as well as high stability, and can meet market demand.

Description

Technical Field

[0001] The present invention relates to the technical field of recycling and cyclic reuse of waste power lithium-ion batteries, and in particular to a direct regeneration and repair process for failed lithium nickel cobalt manganese oxide positive electrode materials and applications thereof. Background Art

[0002] With the rapid development of electric vehicles and energy storage technology, the demand for lithium nickel cobalt manganese oxide positive electrode materials has increased dramatically. However, the main components of lithium nickel cobalt manganese oxide positive electrode materials (such as nickel, cobalt, manganese, etc.) are scarce resources. In order to meet people's daily application needs while improving resource utilization efficiency, it is necessary to repair and reuse failed lithium nickel cobalt manganese oxide positive electrode materials. How to repair failed lithium nickel cobalt manganese oxide positive electrode materials has become a hot topic of research among scientists.

[0003] The prior art already has a treatment method for regenerating and repairing completely failed nickel cobalt manganese oxide positive electrode materials. One method is to subject the completely failed nickel cobalt manganese oxide positive electrode materials to a degradation treatment, followed by an annealing treatment to obtain a pretreated nickel cobalt manganese oxide positive electrode material. The pretreated nickel cobalt manganese oxide positive electrode material is then dispersed in a LiOH solution for a hydrothermal reaction. After the reaction is completed, a retreated nickel cobalt manganese oxide positive electrode material is obtained. Finally, the hydrothermally reacted nickel cobalt manganese oxide positive electrode material is mixed with a small amount of LiOH and then calcined at high temperature twice to obtain a repaired and regenerated nickel cobalt manganese oxide positive electrode material. However, the hydrothermal treatment adopted by the above method is carried out under high temperature and high pressure conditions, and there are safety issues in the lithium replenishment process. It is not applicable to industrial large-scale production (hundreds of kilograms) and is prone to safety hazards.

[0004] Therefore, it is necessary to design a simple, safe and efficient process for directly regenerating and repairing failed nickel cobalt manganese oxide positive electrode materials to solve the above problems. Summary of the Invention

[0005] In response to the defects in the prior art, the present invention proposes a direct regeneration and repair process for failed lithium nickel cobalt manganese oxide positive electrode materials and its application.

[0006] The present invention provides a direct regeneration and repair process for failed lithium nickel cobalt manganese oxide positive electrode materials, comprising the following steps:

[0007] S1: placing the spent lithium nickel cobalt manganese oxide positive electrode material in a sodium hydroxide solution to remove residual aluminum impurities in the spent positive electrode material, and obtaining a preliminarily treated spent lithium nickel cobalt manganese oxide material after stirring, filtering, and drying;

[0008] S2: The spent lithium nickel cobalt manganese oxide material obtained in step S1 is subjected to an impurity removal treatment at 250-500° C. to obtain a pretreated spent lithium nickel cobalt manganese oxide material. This step can remove impurities such as the diaphragm and PVDF in the material;

[0009] S3: The pretreated spent nickel cobalt manganese oxide material obtained in step S2 is mixed with lithium salt and nickel cobalt manganese hydroxide in a mass ratio of 1:0.2:(0.1-0.6) to obtain a mixed material; the mass ratios of the spent nickel cobalt manganese oxide material and lithium salt and nickel cobalt manganese hydroxide are 1:0.2:0.1, 1:0.2:0.2, 1:0.2:0.3, 1:0.2:0.4, 1:0.2:0.5, and 1:0.2:0.6.

[0010] S4: The mixed material obtained in step S3 is heated to 450-650°C in an air atmosphere for the first heat preservation, and then heated to 800-1000°C for the second heat preservation. After the heat preservation is completed, the temperature is cooled to room temperature to obtain a directly regenerated lithium nickel cobalt manganese oxide material.

[0011] The present invention uses a nickel-cobalt-manganese hydroxide precursor for the first time to directly repair failed positive electrode materials. The lithium salt and the precursor are evenly added to the failed lithium nickel-cobalt-manganese oxide by solid mixing, and then the lithium replenishment process is completed after two high-temperature calcinations. This avoids lithium replenishment in a high-pressure closed container, improves the lithium replenishment efficiency and the lithium migration rate, and greatly enhances the repair effect. It can transform the rock salt phase in the failed material into a layered structure, thereby achieving recovery of the failed structure.

[0012] Furthermore, the step S1 also includes screening the initially treated spent lithium nickel cobalt manganese oxide material, where the screening can separate the coarse and fine materials to obtain a powder with uniform particle size; the mesh size used for the screening is 50-300 mesh, such as 50, 100, 150, 200, 250 or 300 mesh.

[0013] Furthermore, the time for the impurity removal treatment in step S2 is 1-5 hours.

[0014] Furthermore, the lithium salt is selected from one or more of lithium hydroxide, lithium carbonate, lithium nitrate and lithium chloride.

[0015] Furthermore, the step S3 further includes doping Nb2O5 with a mass fraction of 0-1% wt. Doping Nb2O5 can further stabilize the layered structure and improve the long-term cycle stability of the regenerated positive electrode material.

[0016] Furthermore, in step S4, the first holding time is 1-3 hours, and the second holding time is 1-5 hours. High-temperature calcination in an air atmosphere can further improve the stability of the repair material.

[0017] Furthermore, the concentration of the sodium hydroxide solution in step S1 is 0.5-3 mol / L.

[0018] Furthermore, the mass ratio of the spent lithium nickel cobalt manganese oxide material pretreated in step S3 to the lithium salt and nickel cobalt manganese hydroxide is 1:0.2:0.2.

[0019] The present invention also provides the application of the direct regeneration and repair process in treating waste power lithium-ion batteries.

[0020] The present invention also provides a lithium nickel cobalt manganese oxide positive electrode material repaired by the direct regeneration repair process.

[0021] In summary, compared with the prior art, the present invention achieves the following technical effects:

[0022] (1) The direct regeneration and repair process for failed lithium nickel cobalt manganese oxide positive electrode materials provided by the present invention completes lithium replenishment by high-temperature calcination after mixing, avoiding the use of closed high-pressure conditions and significantly improving the safety of the repair process;

[0023] (2) The direct regeneration and repair process for failed lithium nickel cobalt manganese oxide positive electrode materials provided by the present invention can directly regenerate positive electrode materials at low cost;

[0024] (3) The direct regeneration and repair process for failed lithium nickel cobalt manganese oxide positive electrode materials provided by the present invention can significantly improve the repair efficiency;

[0025] (4) The direct regeneration and repair process of the failed lithium nickel cobalt manganese oxide positive electrode material provided by the present invention can be calcined in an air atmosphere to achieve the repair and improvement of the electrochemical performance of the material;

[0026] (5) The direct regeneration and repair process of the failed lithium nickel cobalt manganese oxide positive electrode material provided by the present invention is simple to operate and has a short process;

[0027] (6) The direct regeneration and repair process for failed lithium nickel cobalt manganese oxide positive electrode materials provided by the present invention does not have the possibility of polluting the environment when using materials in the repair process, and can reduce CO2 emissions. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0029] Figure 1 This is a charge and discharge curve diagram of the failed nickel cobalt manganese oxide positive electrode material (NCM523) used in Example 1 of the present invention;

[0030] Figure 2This is a charge and discharge curve of the directly regenerated nickel cobalt manganese oxide positive electrode material (NCM523) obtained in Example 1 of the present invention;

[0031] Figure 3 This is a charge and discharge curve diagram of the commercial nickel cobalt manganese oxide positive electrode material (NCM523) used in the present invention;

[0032] Figure 4 This is a charge and discharge curve diagram of the directly regenerated nickel cobalt manganese oxide positive electrode material (NCM523) obtained in Example 4 of the present invention;

[0033] Figure 5 This is a charge and discharge curve diagram of the directly regenerated nickel cobalt manganese oxide positive electrode material (NCM523) obtained in Example 5 of the present invention;

[0034] Figure 6 This is a charge and discharge curve of the directly regenerated nickel cobalt manganese oxide positive electrode material (NCM523) obtained in Comparative Example 1 of the present invention;

[0035] Figure 7 This is a charge and discharge curve of the directly regenerated nickel cobalt manganese oxide positive electrode material (NCM523) obtained in Comparative Example 2 of the present invention;

[0036] Figure 8 This is a comparison chart of the rate performance of the failed lithium nickel cobalt manganese oxide positive electrode material (SNCM523-BM), the directly regenerated lithium nickel cobalt manganese oxide positive electrode material (RNCM523) of Example 1 of the present invention, the commercial lithium nickel cobalt manganese oxide positive electrode material (CNCM523), and the directly regenerated lithium nickel cobalt manganese oxide positive electrode material (rNCM523) of Comparative Example 1 of the present invention;

[0037] Figure 9 It is a comparison chart of the long-term cycling performance of the failed lithium nickel cobalt manganese oxide positive electrode material (SNCM523-BM), the directly regenerated lithium nickel cobalt manganese oxide positive electrode material (RNCM523) of Example 1 of the present invention, the commercial lithium nickel cobalt manganese oxide positive electrode material (CNCM523), and the directly regenerated lithium nickel cobalt manganese oxide positive electrode material (rNCM523) of Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0038] In order to help those skilled in the art better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention are clearly and completely described below. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making any creative efforts should fall within the scope of protection of the present invention.

[0039] Example

[0040] The present invention is further described below with reference to specific examples and comparative examples. The following specific examples are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following examples, and are particularly not limited to the types of the various component raw materials used in the following specific examples.

[0041] 1. The sources of raw materials for the embodiments and comparative examples are as follows:

[0042] Unless otherwise specified, the raw materials used in the examples and comparative examples of the present invention are all commercially available, wherein the spent nickel cobalt manganese oxide positive electrode material (spent NCM523) was purchased from a battery disassembly manufacturer.

[0043] 2. Various performance test methods

[0044] The regenerated and repaired lithium nickel cobalt manganese oxide positive electrode material was prepared into a positive electrode slurry with a mass ratio of positive electrode material: conductive agent SP: binder PVDF: NMP = 80:10:10:100, coated on aluminum foil, and cut into electrode sheets after vacuum drying at 100°C for 12 hours. Subsequently, CR2032 button batteries were assembled in a glove box according to the button battery assembly process.

[0045] (1) Gram capacity performance test: tested by Xinwei battery testing system, the charging cut-off voltage is 4.3V, and the minimum discharge cut-off voltage is 2.5V.

[0046] (2) Long cycle stability test: The test was conducted using the Xinwei battery testing system with a rate set at 0.5C.

[0047] (3) Rate performance test: Test at rates of 0.1C, 0.2C, 0.5C, 1C, 2C, and 4C, with five cycles at each rate.

[0048] Example 1

[0049] S1: placing the spent lithium nickel cobalt manganese oxide positive electrode material in a 1 mol / L sodium hydroxide solution, stirring and filtering, drying at 100° C., and sieving the material using a 300-mesh sieve to obtain a preliminarily treated spent lithium nickel cobalt manganese oxide material;

[0050] S2: performing an impurity removal treatment on the preliminarily treated spent lithium nickel cobalt manganese oxide material obtained in step S1 at 300° C. for 2 hours to obtain a pretreated spent lithium nickel cobalt manganese oxide material;

[0051] S3: The pretreated spent lithium nickel cobalt manganese oxide material obtained in step S2 is mixed with lithium hydroxide and nickel cobalt manganese hydroxide in a mass ratio of 1:0.2:0.2, and then 0.5% wt Nb2O5 is added and ground in a mortar to obtain a mixed material;

[0052] S4: heating the mixture obtained in step S3 to 500° C. at a rate of 5° C. / min in an air atmosphere, holding the mixture for 2 hours, then raising the temperature to 850° C. at a rate of 3° C. / min, holding the mixture for 3 hours, and cooling the mixture to room temperature to obtain a directly regenerated lithium nickel cobalt manganese oxide material;

[0053] Figure 1 This is the charge-discharge curve of the failed lithium nickel cobalt manganese oxide positive electrode material (NCM523) used in Example 1. It can be seen that the capacity of the failed lithium nickel cobalt manganese oxide is less than 20 mAh / g, indicating that the crystal structure of the failed lithium nickel cobalt manganese oxide is severely damaged;

[0054] Figure 2 This is the charge-discharge curve of the repaired and regenerated nickel cobalt manganese oxide cathode material (NCM523) obtained in Example 1. It can be seen that the specific capacity of the material at 0.5C reaches more than 149 mAh / g;

[0055] Figure 3 The charge and discharge curves of commercial nickel cobalt manganese oxide cathode material (NCM523) show that the regenerated cathode material of the present invention is comparable to the commercial cathode material in terms of capacity.

[0056] Figure 8 The direct regeneration of the nickel cobalt manganese oxide cathode material (RNCM523) of Example 1 of the present invention has a capacity of 158.66 mAh / g under 0.1C charge and discharge conditions, which is comparable to the commercial nickel cobalt manganese oxide cathode material (CNCM523). Figure 9 It demonstrated its excellent cycling performance and was able to maintain a capacity retention rate of 81.06% after 250 cycles.

[0057] Example 2

[0058] S1: placing the spent lithium nickel cobalt manganese oxide positive electrode material in a 3 mol / L sodium hydroxide solution, stirring and filtering, drying at 100°C, and sieving the material using a 100-mesh sieve to obtain a preliminarily treated spent lithium nickel cobalt manganese oxide material;

[0059] S2: performing an impurity removal treatment on the preliminarily treated spent lithium nickel cobalt manganese oxide material obtained in step S1 at 500° C. for 1 hour to obtain a pretreated spent lithium nickel cobalt manganese oxide material;

[0060] S3: The pretreated spent lithium nickel cobalt manganese oxide material obtained in step S2 is mixed with lithium hydroxide and nickel cobalt manganese hydroxide in a mass ratio of 1:0.2:0.2, and then 0.1% wt Nb2O5 is added and ground in a mortar to obtain a mixed material;

[0061] S4: The mixed material obtained in step S3 is heated to 450°C at a rate of 5°C / min in an air atmosphere, and kept warm for 3 hours for the first time. The temperature is then raised to 1000°C at a rate of 3°C / min, and kept warm for 1 hour. After the insulation is completed, the temperature is cooled to room temperature to obtain a directly regenerated lithium nickel cobalt manganese oxide material.

[0062] Example 3

[0063] S1: placing the spent lithium nickel cobalt manganese oxide positive electrode material in a 0.5 mol / L sodium hydroxide solution, stirring and filtering, drying at 100° C., and sieving the material using a 50-mesh sieve to obtain a preliminarily treated spent lithium nickel cobalt manganese oxide material;

[0064] S2: The preliminarily treated spent lithium nickel cobalt manganese oxide material obtained in step S1 is subjected to an impurity removal treatment at 250° C. for 5 hours to obtain a pretreated spent lithium nickel cobalt manganese oxide material;

[0065] S3: The pretreated spent lithium nickel cobalt manganese oxide material obtained in step S2 is mixed with lithium nitrate and nickel cobalt manganese hydroxide in a mass ratio of 1:0.2:0.2, and then 1% wt Nb2O5 is added and ground in a mortar to obtain a mixed material;

[0066] S4: The mixed material obtained in step S3 is heated to 650°C at a rate of 5°C / min in an air atmosphere, and kept warm for 1 hour for the first time. The temperature is then raised to 900°C at a rate of 3°C / min and kept warm for 2 hours. After the insulation is completed, the temperature is cooled to room temperature to obtain a directly regenerated lithium nickel cobalt manganese oxide material.

[0067] Example 4

[0068] S1: placing the spent lithium nickel cobalt manganese oxide positive electrode material in a 1 mol / L sodium hydroxide solution, stirring and filtering, drying at 100° C., and sieving the material using a 300-mesh sieve to obtain a preliminarily treated spent lithium nickel cobalt manganese oxide material;

[0069] S2: performing an impurity removal treatment on the preliminarily treated spent lithium nickel cobalt manganese oxide material obtained in step S1 at 300° C. for 2 hours to obtain a pretreated spent lithium nickel cobalt manganese oxide material;

[0070] S3: The pretreated spent lithium nickel cobalt manganese oxide material obtained in step S2 is mixed with lithium hydroxide and nickel cobalt manganese hydroxide in a mass ratio of 1:0.2:0.1, and then 0.5% wt Nb2O5 is added and ground in a mortar to obtain a mixed material;

[0071] S4: The mixture obtained in step S3 is heated to 500°C at a rate of 5°C / min in an air atmosphere, and kept warm for 2 hours for the first time. The temperature is then raised to 850°C at a rate of 3°C / min, and kept warm for 3 hours. After the insulation is completed, the temperature is cooled to room temperature to obtain a repaired lithium nickel cobalt manganese oxide material.

[0072] Example 5

[0073] S1: placing the spent lithium nickel cobalt manganese oxide positive electrode material in a 1 mol / L sodium hydroxide solution, stirring and filtering, drying at 100° C., and sieving the material using a 300-mesh sieve to obtain a preliminarily treated spent lithium nickel cobalt manganese oxide material;

[0074] S2: performing an impurity removal treatment on the preliminarily treated spent lithium nickel cobalt manganese oxide material obtained in step S1 at 300° C. for 2 hours to obtain a pretreated spent lithium nickel cobalt manganese oxide material;

[0075] S3: The pretreated spent lithium nickel cobalt manganese oxide material obtained in step S2 is mixed with lithium hydroxide and nickel cobalt manganese hydroxide in a mass ratio of 1:0.2:0.6, and then 0.5% wt Nb2O5 is added and ground in a mortar to obtain a mixed material;

[0076] S4: The mixture obtained in step S3 is heated to 500°C at a rate of 5°C / min in an air atmosphere, and kept warm for 2 hours for the first time. The temperature is then raised to 850°C at a rate of 3°C / min, and kept warm for 3 hours. After the insulation is completed, the temperature is cooled to room temperature to obtain a repaired lithium nickel cobalt manganese oxide material.

[0077] Comparative Example 1

[0078] S1: placing the spent lithium nickel cobalt manganese oxide positive electrode material in a 1 mol / L sodium hydroxide solution, stirring and filtering, drying at 100° C., and sieving the material using a 300-mesh sieve to obtain a preliminarily treated spent lithium nickel cobalt manganese oxide material;

[0079] S2: performing an impurity removal treatment on the preliminarily treated spent lithium nickel cobalt manganese oxide material obtained in step S1 at 300° C. for 2 hours to obtain a pretreated spent lithium nickel cobalt manganese oxide material;

[0080] S3: The pretreated spent lithium nickel cobalt manganese oxide material obtained in step S2 is mixed with lithium hydroxide and nickel cobalt manganese hydroxide in a mass ratio of 1:0.2:0, and then 0.5% wt Nb2O5 is added and ground in a mortar to obtain a mixed material;

[0081] S4: The mixture obtained in step S3 is heated to 500°C at a rate of 5°C / min in an air atmosphere, and kept warm for 2 hours for the first time. The temperature is then raised to 850°C at a rate of 3°C / min, and kept warm for 3 hours. After the insulation is completed, the temperature is cooled to room temperature to obtain a repaired lithium nickel cobalt manganese oxide material.

[0082] Comparative Example 2

[0083] S1: placing the spent lithium nickel cobalt manganese oxide positive electrode material in a 1 mol / L sodium hydroxide solution, stirring and filtering, drying at 100° C., and sieving the material using a 300-mesh sieve to obtain a preliminarily treated spent lithium nickel cobalt manganese oxide material;

[0084] S2: performing an impurity removal treatment on the preliminarily treated spent lithium nickel cobalt manganese oxide material obtained in step S1 at 300° C. for 2 hours to obtain a pretreated spent lithium nickel cobalt manganese oxide material;

[0085] S3: The pretreated spent lithium nickel cobalt manganese oxide material obtained in step S2 is mixed with lithium hydroxide and nickel cobalt manganese hydroxide in a mass ratio of 1:0.2:0.7, and then 0.5% wt Nb2O5 is added and ground in a mortar to obtain a mixed material;

[0086] S4: The mixture obtained in step S3 is heated to 500°C at a rate of 5°C / min in an air atmosphere, and kept warm for 2 hours for the first time. The temperature is then raised to 850°C at a rate of 3°C / min, and kept warm for 3 hours. After the insulation is completed, the temperature is cooled to room temperature to obtain a repaired lithium nickel cobalt manganese oxide material.

[0087] The electrochemical performance of the regenerated and repaired nickel cobalt manganese oxide positive electrode materials provided in Examples 1-5 and Comparative Examples 1-2 was tested and compared with the test results of the commercial nickel cobalt manganese oxide positive electrode material NCM523. The results are shown in Table 1:

[0088] Table 1. Performance test results of examples and comparative examples

[0089]

[0090] By comparing Example 1, Examples 4-5 with Comparative Examples 1-2, it can be seen that the addition amount of the precursor nickel cobalt manganese hydroxide will affect the regeneration effect. As the amount of the precursor increases, the capacity will increase, but when the addition amount exceeds a certain proportion, the capacity will decrease to a certain extent. Increasing the proportion of the precursor can improve the lithium replenishment efficiency and the lithium migration rate, but adding too little or too much will inhibit this process, resulting in a worse repair effect.

[0091] The test data in Table 1 on the battery capacity under 0.5C charge and discharge conditions and the capacity retention rate after 250 cycles under 0.5C charge and discharge conditions show that the direct regeneration and repair process in Examples 1-5 of the present invention is adopted, by pre-treating the failed nickel cobalt manganese oxide positive electrode material, adding a special precursor and a lithium salt thereto, and then calcining it in two steps under an air atmosphere to obtain the regenerated and repaired nickel cobalt manganese oxide positive electrode material. The electrochemical performance is significantly improved and can meet the standards for commercial applications, which has obvious advantages over the comparative example.

[0092] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A direct regeneration and repair process for failed lithium nickel cobalt manganese oxide positive electrode materials, characterized in that: The steps include: S1: placing the spent lithium nickel cobalt manganese oxide positive electrode material in a sodium hydroxide solution, stirring, filtering, and drying to obtain a preliminarily treated spent lithium nickel cobalt manganese oxide material; S2: performing impurity removal treatment on the preliminarily treated spent lithium nickel cobalt manganese oxide material obtained in step S1 at 250-500° C. to obtain a pretreated spent lithium nickel cobalt manganese oxide material; S3: mixing the pretreated spent lithium nickel cobalt manganese oxide material obtained in step S2 with lithium salt and nickel cobalt manganese hydroxide in a mass ratio of 1:0.2:(0.1-0.6) to obtain a mixed material; S4: heating the mixed material obtained in step S3 to 450-650°C in an air atmosphere for a first heat preservation, then heating it to 800-1000°C for a second heat preservation, and cooling it to room temperature after the heat preservation to obtain a directly regenerated lithium nickel cobalt manganese oxide material; In step S4, the first insulation time is 1-3 hours, and the second insulation time is 1-5 hours.

2. The direct regeneration repair process according to claim 1, characterized in that: The step S1 further includes sieving the initially treated spent lithium nickel cobalt manganese oxide material, with the mesh size used for the sieving being 50-300 meshes.

3. The direct regeneration repair process according to claim 1, characterized in that: The time for the impurity removal treatment in step S2 is 1-5 hours.

4. The direct regeneration repair process according to claim 1, characterized in that: The lithium salt is selected from one or more of lithium hydroxide, lithium carbonate, lithium nitrate and lithium chloride.

5. The direct regeneration repair process according to claim 1, characterized in that: The step S3 further includes doping Nb2O5 with a mass fraction of 0-1%wt.

6. The direct regeneration repair process according to claim 1, characterized in that: The concentration of the sodium hydroxide solution in step S1 is 0.5-3 mol / L.

7. The direct regeneration repair process according to claim 1, characterized in that: The mass ratio of the spent lithium nickel cobalt manganese oxide material pretreated in step S3 to the lithium salt and nickel cobalt manganese hydroxide is 1:0.2:0.

2.

8. Use of the direct regeneration and repair process according to any one of claims 1 to 7 in the treatment of waste power lithium-ion batteries.

9. The lithium nickel cobalt manganese oxide positive electrode material repaired by the direct regeneration repair process according to any one of claims 1 to 7.

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