A nickel-rich positive electrode material, a preparation method and application thereof
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GEM WUXI ENERGY MATERIAL CO LTD
- Filing Date
- 2026-05-29
- Publication Date
- 2026-08-04
AI Technical Summary
[0006]本发明提供了一种富镍正极材料及其制备方法和应用，以解决现有技术中富镍正极材料容量快速衰减、循环稳定性较差的问题
本发明提供的富镍正极材料的制备方法，通过调控升温速率，大幅提升低温阶段的界面传质效率，使得锂化反应均匀进行，最终形成均匀分布的纳米孔隙与均匀的初级颗粒结构，使得电池在充放电过程中有效分散H2-H3相变产生的各向异性体积应力，避免应力集中与晶间裂纹，从而提升了富镍正极材料的机械稳定性，进而提升了电池的容量和循环稳定性。
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Abstract
Description
Technical Field
[0001] This invention relates to the field of lithium-ion battery technology, specifically to a nickel-rich cathode material, its preparation method, and its application. Background Technology
[0002] Lithium-ion batteries, as a core technology in the current energy storage field, are widely used in consumer electronics, new energy vehicles, and large-scale energy storage systems. With the increasing market demand for battery energy density, nickel-rich layered oxide cathode materials (Ni content ≥ 0.8%) have become one of the core candidate materials for next-generation high-energy-density lithium-ion batteries due to their high specific capacity, high operating voltage, and relatively low cost. Among them, cobalt-free nickel-rich cathode material LiNi... 0.9 Mn 0.1 O2, in particular, has become a hot topic in industry research due to its further elimination of expensive cobalt.
[0003] However, increasing the nickel content in cathode materials can easily lead to significant anisotropic volume changes during charging and discharging. The non-uniform microstructure of conventional nickel-rich materials can cause stress concentration, thereby exacerbating the chemical and mechanical instability of the material, triggering intergranular cracks, electrolyte penetration, and interfacial side reactions, which in turn cause rapid capacity decay and severely limit the cycle life of the material.
[0004] To address the aforementioned problems, existing technologies introduce W... 6+ Mo 6+ Heterogeneous elements can regulate the order of cations and suppress volume changes, but this method requires precise control of the distribution of doping elements. Furthermore, the introduction of heterogeneous elements increases the cost of raw materials and may reduce the proportion of active materials in the material, which is not conducive to large-scale industrial applications.
[0005] Therefore, developing a simple and low-cost method for preparing nickel-rich cathode materials has become a pressing technical problem to be solved in this field. Summary of the Invention
[0006] This invention provides a nickel-rich cathode material, its preparation method, and its application, in order to solve the problems of rapid capacity decay and poor cycle stability of nickel-rich cathode materials in the prior art.
[0007] In a first aspect, the present invention provides a method for preparing a nickel-rich cathode material, comprising the following steps: S1, mixing and reacting a mixed solution containing a nickel source and a manganese source, a precipitant, and a chelating agent, aging, filtering, washing, and drying to obtain a precursor; S2, mixing the precursor with a lithium source, grinding, performing a first sintering, and a second sintering to obtain the nickel-rich cathode material; wherein the heating rate of the first sintering is 2℃ / min~4℃ / min, the temperature of the first sintering is 220℃-270℃, and the holding time of the first sintering is 4h-6h; wherein the heating rate of the second sintering is 9℃ / min~12℃ / min, the temperature of the second sintering is 750℃-790℃, and the holding time of the second sintering is 8h-12h.
[0008] In some alternative embodiments, the nickel source includes at least one of nickel sulfate and nickel nitrate.
[0009] In some alternative embodiments, the manganese source includes at least one of manganese sulfate and manganese nitrate.
[0010] In some alternative embodiments, the precipitant comprises a sodium hydroxide solution.
[0011] In some alternative embodiments, the chelating agent comprises an aqueous ammonia solution.
[0012] In some alternative embodiments, the concentration of the precipitant is 3 mol / L to 6 mol / L.
[0013] In some alternative embodiments, the concentration of the chelating agent is 9 mol / L to 12 mol / L.
[0014] In some optional embodiments, the molar ratio of nickel in the nickel source to manganese in the manganese source is (0.9-0.93):(0.07-0.1).
[0015] In some optional embodiments, the volume ratio of the mixed solution to the precipitant is 1:(0.8-2).
[0016] In some alternative embodiments, the pH of the reaction is adjusted by a chelating agent, wherein the pH is 10.5-11.5.
[0017] In some optional embodiments, in step S1, the reaction temperature is 40℃-50℃ and the reaction time is 10h-14h.
[0018] In some alternative implementations, the aging time in step S1 is 4h-10h.
[0019] In some optional embodiments, in step S2, the lithium source includes at least one of lithium hydroxide, lithium carbonate, and lithium nitrate.
[0020] In some optional embodiments, in step S2, the molar ratio of lithium in the lithium source to nickel in the nickel source is (1-1.03):(0.9-0.93).
[0021] In some optional embodiments, in step S2, the grinding speed is 7000rpm-9000rpm; the grinding time is 5min-20min.
[0022] In a second aspect, the present invention provides a nickel-rich cathode material, which is prepared by the preparation method described in the first aspect.
[0023] Thirdly, the present invention provides a lithium-ion battery, the lithium-ion battery comprising the nickel-rich cathode material described in the second aspect or the nickel-rich cathode material prepared by the preparation method described in the first aspect.
[0024] Compared with the prior art, the present invention has the following beneficial effects: The method for preparing nickel-rich cathode material provided by this invention significantly improves the interfacial mass transfer efficiency at low temperatures by controlling the heating rate, enabling the lithiation reaction to proceed uniformly and ultimately forming uniformly distributed nanopores and a uniform primary particle structure. This allows the battery to effectively disperse the anisotropic volumetric stress generated by the H2-H3 phase transition during charging and discharging, avoiding stress concentration and intergranular cracks, thereby improving the mechanical stability of the nickel-rich cathode material and consequently enhancing the battery's capacity and cycle stability. Attached Figure Description
[0025] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0026] Figure 1 This is a cross-sectional microstructure diagram of the nickel-rich cathode material prepared in Example 1 of the present invention; a is a secondary electron morphology contrast diagram, and b is a primary particle segmentation diagram; Figure 2 This is a cross-sectional microstructure diagram of the nickel-rich cathode material prepared in Comparative Example 1 of this invention; a is a secondary electron morphology contrast diagram, and b is a primary particle segmentation diagram. Detailed Implementation
[0027] The following embodiments are provided to better understand the present invention, but the following embodiments do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the scope of protection of the present invention.
[0028] Unless otherwise specified, all experimental steps or conditions in the examples were performed according to conventional experimental procedures and conditions in the art. Reagents or instruments whose manufacturers are not specified are all commercially available products.
[0029] Example 1 This embodiment provides a method for preparing a nickel-rich cathode material, including the following steps: (1) Prepare a mixed solution of NiSO4·6H2O and MnSO4·H2O with a total concentration of 2 mol / L, a NaOH solution of 4 mol / L, and an ammonia solution of 10.5 mol / L; wherein the molar ratio of NiSO4·6H2O and MnSO4·H2O in the mixed solution is 9:1; (2) The mixed solution, NaOH solution, and ammonia solution were pumped in separately, and the pH of the reaction was controlled to be 11.0 with ammonia solution. The reaction was stirred at 45°C for 12 h. After the reaction was completed, the mixture was aged for 6 h, filtered, washed with deionized water until neutral, and then dried under vacuum at 110°C for 12 h to obtain Ni. 0.9 Mn 0.1 (OH)2 precursor; wherein the volume ratio of the mixed solution and the NaOH solution is 1:1, the pumping rate of the mixed solution is 50 mL / min, the pumping rate of the NaOH solution is 50 mL / min, and the pumping rate of the ammonia solution is 15 mL / min; (3) Ni 0.9 Mn 0.1 (OH)2 precursor and LiOH·H2O were mixed at a molar ratio of 1:1.03 and ground at 8000 rpm for 10 min. The mixture was then heated to 250 °C at a rate of 2 °C / min in an oxygen atmosphere and held at 250 °C for 5 h. After that, the mixture was heated to 770 °C at a rate of 10 °C / min and held at 770 °C for 10 h. The mixture was then allowed to cool naturally to room temperature to obtain a nickel-rich cathode material.
[0030] Example 2 This embodiment provides a method for preparing a nickel-rich cathode material, including the following steps: (1) Prepare a mixed solution of NiSO4·6H2O and MnSO4·H2O with a total concentration of 2 mol / L, a NaOH solution of 4 mol / L, and an ammonia solution of 10.5 mol / L; wherein the molar ratio of NiSO4·6H2O and MnSO4·H2O in the mixed solution is 93:7; (2) The mixed solution, NaOH solution, and ammonia solution were pumped in separately, and the pH of the reaction was controlled to be 11.0 with ammonia solution. The reaction was stirred at 45°C for 12 h. After the reaction was completed, the mixture was aged for 6 h, filtered, washed with deionized water until neutral, and then dried under vacuum at 110°C for 12 h to obtain Ni. 0.93 Mn 0.07 (OH)2 precursor; wherein the volume ratio of the mixed solution and the NaOH solution is 1:1, the pumping rate of the mixed solution is 50 mL / min, the pumping rate of the NaOH solution is 50 mL / min, and the pumping rate of the ammonia solution is 15 mL / min; (3) Ni 0.93 Mn 0.07 (OH)2 precursor and LiOH·H2O were mixed at a molar ratio of 1:1.03 and ground at 8000 rpm for 10 min. The mixture was then heated to 250 °C at a rate of 2 °C / min in an oxygen atmosphere and held at 250 °C for 5 h. After that, the mixture was heated to 770 °C at a rate of 10 °C / min and held at 770 °C for 10 h. The mixture was then allowed to cool naturally to room temperature to obtain a nickel-rich cathode material.
[0031] Example 3 This embodiment provides a method for preparing a nickel-rich cathode material, including the following steps: (1) Prepare a mixed solution of NiSO4·6H2O and MnSO4·H2O with a total concentration of 2 mol / L, a NaOH solution of 4 mol / L, and an ammonia solution of 10.5 mol / L; wherein the molar ratio of NiSO4·6H2O and MnSO4·H2O in the mixed solution is 9:1; (2) The mixed solution, NaOH solution, and ammonia solution were pumped in separately, and the pH of the reaction was controlled to be 11.0 with ammonia solution. The reaction was stirred at 45°C for 12 h. After the reaction was completed, the mixture was aged for 8 h, filtered, washed with deionized water until neutral, and then dried under vacuum at 110°C for 12 h to obtain Ni. 0.9 Mn 0.1 (OH)2 precursor; wherein the volume ratio of the mixed solution and the NaOH solution is 1:1, the pumping rate of the mixed solution is 50 mL / min, the pumping rate of the NaOH solution is 50 mL / min, and the pumping rate of the ammonia solution is 15 mL / min; (3) Ni 0.9 Mn 0.1(OH)2 precursor and LiOH·H2O were mixed at a molar ratio of 1:1.01 and ground at 8000 rpm for 15 min. The mixture was then heated to 200 °C at a rate of 2 °C / min in an oxygen atmosphere and held at 200 °C for 5 h. After that, the mixture was heated to 770 °C at a rate of 10 °C / min and held at 770 °C for 10 h. The mixture was then allowed to cool naturally to room temperature to obtain a nickel-rich cathode material.
[0032] Example 4 This embodiment provides a method for preparing a nickel-rich cathode material, including the following steps: (1) Prepare a mixed solution of NiSO4·6H2O and MnSO4·H2O with a total concentration of 2 mol / L, a NaOH solution of 4 mol / L, and an ammonia solution of 10.5 mol / L; wherein the molar ratio of NiSO4·6H2O and MnSO4·H2O in the mixed solution is 9:1; (2) The mixed solution, NaOH solution, and ammonia solution were pumped in separately, and the pH of the reaction was controlled to be 11.0 with ammonia solution. The reaction was stirred at 45°C for 12 h. After the reaction was completed, the mixture was aged for 6 h, filtered, washed with deionized water until neutral, and then dried under vacuum at 110°C for 12 h to obtain Ni. 0.9 Mn 0.1 (OH)2 precursor; wherein the volume ratio of the mixed solution and the NaOH solution is 1:1, the pumping rate of the mixed solution is 50 mL / min, the pumping rate of the NaOH solution is 50 mL / min, and the pumping rate of the ammonia solution is 15 mL / min; (3) Ni 0.9 Mn 0.1 (OH)2 precursor and LiOH·H2O were mixed at a molar ratio of 1:1.03 and ground at 8000 rpm for 10 min. The mixture was then heated to 250 °C at a rate of 2 °C / min in an oxygen atmosphere and held at 250 °C for 5 h. After that, the mixture was heated to 790 °C at a rate of 12 °C / min and held at 790 °C for 10 h. The mixture was then allowed to cool naturally to room temperature to obtain a nickel-rich cathode material.
[0033] Comparative Example 1 This comparative example provides a method for preparing a nickel-rich cathode material, including the following steps: (1) Prepare a mixed solution of NiSO4·6H2O and MnSO4·H2O with a total concentration of 2 mol / L, a NaOH solution of 4 mol / L, and an ammonia solution of 10.5 mol / L; wherein the molar ratio of NiSO4·6H2O and MnSO4·H2O in the mixed solution is 9:1; (2) The mixed solution, NaOH solution, and ammonia solution were pumped in separately, and the pH of the reaction was controlled to be 11.0 with ammonia solution. The reaction was stirred at 45°C for 12 h. After the reaction was completed, the mixture was aged for 6 h, filtered, washed with deionized water until neutral, and then dried under vacuum at 110°C for 12 h to obtain Ni. 0.9 Mn 0.1 (OH)2 precursor; wherein the volume ratio of the mixed solution and the NaOH solution is 1:1, the pumping rate of the mixed solution is 50 mL / min, the pumping rate of the NaOH solution is 50 mL / min, and the pumping rate of the ammonia solution is 15 mL / min; (3) Ni 0.9 Mn 0.1 (OH)2 precursor and LiOH·H2O were mixed at a molar ratio of 1:1.03, ground at 8000 rpm for 10 min, heated to 770℃ at a rate of 2℃ / min in an oxygen atmosphere, and held at 770℃ for 10 h to obtain nickel-rich cathode material.
[0034] Comparative Example 2 This comparative example provides a method for preparing a nickel-rich cathode material, including the following steps: (1) Prepare a mixed solution of NiSO4·6H2O and MnSO4·H2O with a total concentration of 2 mol / L, a NaOH solution of 4 mol / L, and an ammonia solution of 10.5 mol / L; wherein the molar ratio of NiSO4·6H2O and MnSO4·H2O in the mixed solution is 9:1; (2) The mixed solution, NaOH solution, and ammonia solution were pumped in separately, and the pH of the reaction was controlled to be 11.0 with ammonia solution. The reaction was stirred at 45°C for 12 h. After the reaction was completed, the mixture was aged for 6 h, filtered, washed with deionized water until neutral, and then dried under vacuum at 110°C for 12 h to obtain Ni. 0.9 Mn 0.1 (OH)2 precursor; wherein the volume ratio of the mixed solution and the NaOH solution is 1:1, the pumping rate of the mixed solution is 50 mL / min, the pumping rate of the NaOH solution is 50 mL / min, and the pumping rate of the ammonia solution is 15 mL / min; (3) Ni 0.9 Mn 0.1 (OH)2 precursor and LiOH·H2O were mixed at a molar ratio of 1:1.03, ground at 8000 rpm for 10 min, heated to 770℃ at a rate of 10℃ / min in an oxygen atmosphere, and held at 770℃ for 10 h to obtain nickel-rich cathode material.
[0035] Comparative Example 3 This comparative example provides a method for preparing a nickel-rich cathode material, including the following steps: (1) Prepare a mixed solution of NiSO4·6H2O and MnSO4·H2O with a total concentration of 2 mol / L, a NaOH solution of 4 mol / L, and an ammonia solution of 10.5 mol / L; wherein the molar ratio of NiSO4·6H2O and MnSO4·H2O in the mixed solution is 9:1; (2) The mixed solution, NaOH solution, and ammonia solution were pumped in separately, and the pH of the reaction was controlled to be 11.0 with ammonia solution. The reaction was stirred at 45°C for 12 h. After the reaction was completed, the mixture was aged for 6 h, filtered, washed with deionized water until neutral, and then dried under vacuum at 110°C for 12 h to obtain Ni. 0.9 Mn 0.1 (OH)2 precursor; wherein the volume ratio of the mixed solution and the NaOH solution is 1:1, the pumping rate of the mixed solution is 50 mL / min, the pumping rate of the NaOH solution is 50 mL / min, and the pumping rate of the ammonia solution is 15 mL / min; (3) Ni 0.9 Mn 0.1 (OH)2 precursor and LiOH·H2O were mixed at a molar ratio of 1:1.03 and ground at 8000 rpm for 10 min. The mixture was then heated to 250 °C at a rate of 10 °C / min in an oxygen atmosphere and held at 250 °C for 5 h. After that, the mixture was heated to 770 °C at a rate of 10 °C / min and held at 770 °C for 10 h. The mixture was then allowed to cool naturally to room temperature to obtain a nickel-rich cathode material.
[0036] Comparative Example 4 This comparative example provides a method for preparing a tungsten-doped nickel-rich cathode material, including the following steps: (1) Prepare a mixed solution of NiSO4·6H2O and MnSO4·H2O with a total concentration of 2 mol / L, a NaOH solution of 4 mol / L, and an ammonia solution of 10.5 mol / L; wherein the molar ratio of NiSO4·6H2O and MnSO4·H2O in the mixed solution is 9:1; (2) The mixed solution, NaOH solution, and ammonia solution were pumped in separately, and the pH of the reaction was controlled to be 11.0 with ammonia solution. The reaction was stirred at 45°C for 12 h. After the reaction was completed, the mixture was aged for 6 h, filtered, washed with deionized water until neutral, and then dried under vacuum at 110°C for 12 h to obtain Ni. 0.9 Mn 0.1 (OH)2 precursor; wherein the volume ratio of the mixed solution and the NaOH solution is 1:1, the pumping rate of the mixed solution is 50 mL / min, the pumping rate of the NaOH solution is 50 mL / min, and the pumping rate of the ammonia solution is 15 mL / min; (3) Ni 0.9 Mn0.1 (OH)₂ precursor, LiOH·H₂O, and ammonium tungstate were mixed and ground at 8000 rpm for 10 min. The mixture was then heated to 770 °C at a rate of 2 °C / min in an oxygen atmosphere and held at 770 °C for 10 h. After natural cooling to room temperature, a tungsten-doped nickel-rich cathode material was obtained. Ni 0.9 Mn 0.1 The molar ratio of tungsten in the (OH)2 precursor, LiOH·H2O and ammonium tungstate is 1:1.03:0.02.
[0037] Microstructure characterization The nickel-rich cathode materials prepared in Example 1 and Comparative Example 1 were characterized by electron backscattering diffraction (EBSD). Figure 1 and Figure 2 It can be seen that the primary particles of the nickel-rich cathode material prepared in Example 1 are uniform in size and regular in morphology; while the particles of the nickel-rich cathode material prepared in Comparative Example 1 are uneven in size and have poor structural consistency. This indicates that stepwise sintering and reasonable control of the heating rate can effectively suppress cation mixing, reduce lattice distortion, and reduce micro-strain, thereby significantly improving the regularity and consistency of the material's microstructure.
[0038] Performance testing The positive electrode materials prepared in Examples 1-4 and Comparative Examples 1-4 were then used to prepare positive electrode sheets with conductive carbon black and PVDF (polyvinylidene fluoride) in a mass ratio of 90:5.5:4.5. Lithium metal sheet was used as the negative electrode, polypropylene as the separator, and 1 mol / L LiPF6 EC / DMC / EMC (volume ratio 1:1:1) solution as the electrolyte. CR2032 coin cells were assembled in an argon glove box, and their electrochemical performance was tested using the Xinwei Battery Testing System. The test results are shown in Table 1.
[0039] The test conditions for the first discharge specific capacity are as follows: under constant temperature conditions of 25℃, the battery is charged to 4.3V at 0.3C, then fully charged at a constant voltage of 4.3V, and discharged to 2.5V at 0.3C once to obtain the specific capacity of the first discharge.
[0040] The cycle performance test method is as follows: the temperature is 25℃, the charging cut-off voltage is 4.3V, the discharging cut-off voltage is 2.5V, the battery is cycled at 0.3C / 0.3C for 100 cycles, and the discharge capacity retention rate after 100 cycles is calculated.
[0041] Capacity retention rate over 100 cycles = (Specific capacity at discharge on cycle 100 / Specific capacity at discharge on cycle 1) × 100% Table 1 Performance test results of each embodiment and comparative example
[0042] As shown in Table 1, the initial discharge specific capacity of the battery prepared by the nickel-rich cathode material prepared by the method provided by the present invention is in the range of 216.5 mAh / g to 220.5 mAh / g, which is higher than that of Comparative Examples 1-4 (201.4 mAh / g to 216.2 mAh / g). The capacity retention rate after 100 cycles is 92.1% to 96.5%, which is higher than that of Comparative Examples 1-3 (82.3% to 88.4%). At the same time, the capacity retention rate after 100 cycles of the tungsten-doped nickel-rich cathode material prepared by conventional methods in Example 1 and Comparative Example 4 is comparable to that of the cathode material prepared by doping modification, indicating that the nickel-rich cathode material prepared by the method provided by the present invention can achieve electrochemical performance comparable to that of the cathode material prepared by doping modification simply by controlling the heating rate. This effectively improves the capacity and cycle stability of the nickel-rich cathode material while reducing cost and process complexity.
[0043] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.
Claims
1. A method for preparing a nickel-rich cathode material, characterized in that, Includes the following steps: S1. A mixed solution containing nickel source and manganese source, precipitant and chelating agent are mixed, reacted, aged, filtered, washed and dried to obtain the precursor; S2. The precursor is mixed with a lithium source, ground, sintered for the first time, and sintered for the second time to obtain the nickel-rich cathode material; The heating rate of the first sintering is 2℃ / min~4℃ / min, and the temperature of the first sintering is 220℃-270℃; The holding time for the first sintering is 4-6 hours. The heating rate of the second sintering is 9℃ / min~12℃ / min, the second sintering temperature is 750℃-790℃, and the holding time of the second sintering is 8h-12h.
2. The method for preparing the nickel-rich cathode material according to claim 1, characterized in that, The nickel source includes at least one of nickel sulfate and nickel nitrate; Preferably, the manganese source includes at least one of manganese sulfate and manganese nitrate.
3. The method for preparing the nickel-rich cathode material according to claim 2, characterized in that, The precipitant includes a sodium hydroxide solution; Preferably, the chelating agent comprises an aqueous ammonia solution.
4. The method for preparing the nickel-rich cathode material according to claim 3, characterized in that, The concentration of the precipitant is 3 mol / L-6 mol / L; Preferably, the concentration of the chelating agent is 9 mol / L-12 mol / L.
5. The method for preparing the nickel-rich cathode material according to claim 4, characterized in that, The molar ratio of nickel in the nickel source to manganese in the manganese source is (0.9-0.93):(0.07-0.1). Preferably, the volume ratio of the mixed solution to the precipitant is 1:(0.8-2). Preferably, the pH of the reaction is adjusted by a chelating agent, wherein the pH is 10.5-11.
5.
6. The method for preparing the nickel-rich cathode material according to claim 5, characterized in that, In step S1, the reaction temperature is 40℃-50℃, and the reaction time is 10h-14h. Preferably, in step S1, the aging time is 4h-10h.
7. The method for preparing the nickel-rich cathode material according to claim 6, characterized in that, In step S2, the lithium source includes at least one of lithium hydroxide, lithium carbonate, and lithium nitrate; Preferably, in step S2, the molar ratio of lithium in the lithium source to nickel in the nickel source is (1-1.03):(0.9-0.93).
8. The method for preparing the nickel-rich cathode material according to claim 7, characterized in that, In step S2, the grinding speed is 7000rpm-9000rpm; the grinding time is 5min-20min.
9. A nickel-rich cathode material, characterized in that, The nickel-rich cathode material is prepared by the preparation method described in any one of claims 1-8.
10. A lithium-ion battery, characterized in that, The lithium-ion battery includes a nickel-rich cathode material prepared by the preparation method according to any one of claims 1-8 or the nickel-rich cathode material according to claim 9.