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EP-4737398-A2 - MODIFIED HIGH-NICKEL TERNARY POSITIVE ELECTRODE MATERIAL AND PREPARATION METHOD THEREFOR, AND POWER-CONSUMING APPARATUS

EP4737398A2EP 4737398 A2EP4737398 A2EP 4737398A2EP-4737398-A2

Abstract

Provided in the present application is a modified high-nickel ternary positive electrode material, containing a core, an inner coating layer and an outer coating layer. The core contains a high-nickel ternary positive electrode material matrix, which is doped with M1, M2 and W, wherein M1 is one of Mo, Zr, Ti, Sb, Nb and Te; and M2 is one of Mg, Al, Ca, Zn and Sr. The chemical formula of the high-nickel ternary positive electrode material matrix doped with M1, M2 and W is Li 1+a [Ni x Co y Mn z M1 b M2 c W d ]O 2 , wherein 0.65 ≤ x < 1; 0 ≤ y < 0.3; 0 ≤ z < 0.3; 0 < a < 0.2; 0< b < 0.1; 0 < c < 0.1; 0 < d < 0.1; x + y + z + b + c + d = 1; and optionally, 0.8 ≤ x < 1. The surface layer of the core is further doped with Co. The inner coating layer is a Co-containing compound, and the outer coating layer is an Al-containing compound and a B-containing compound. The present application also relates to a method for preparing a modified high-nickel ternary positive electrode material, and a secondary battery, a battery module, a battery pack and a power-consuming apparatus.

Inventors

  • WU, QI
  • CHEN, QIANG
  • ZHAO, Yuxiang
  • FAN, Jingpeng
  • HUANG, QISEN

Assignees

  • Contemporary Amperex Technology (Hong Kong) Limited

Dates

Publication Date
20260506
Application Date
20220601

Claims (12)

  1. A method for preparing a modified high-nickel ternary positive electrode material, characterized by comprising: step S1: mixing and sintering a lithium salt, a high-nickel ternary precursor doped with W, an M1-containing compound, and an M2-containing compound, to obtain a high-nickel ternary positive electrode material matrix doped with M1, M2, and optionally W, wherein a chemical formula of the high-nickel ternary precursor optionally doped with W is (Ni X Co Y Mn Z W D )(OH) 2 , wherein 0.65 ≤ X < 1, 0 ≤ Y < 0.3, 0 ≤ Z < 0.3, 0 < D < 0.1, M1 is one of Mo, Zr, Ti, Sb, Nb, and Te, M2 is one of Mg, Al, Ca, Zn, and Sr, and a chemical formula of the high-nickel ternary positive electrode material matrix doped with M1, M2, and optionally W is Li 1+a [Ni x Co y Mn z M1 b M2 c W d ]O 2 , wherein 0.65 ≤ x < 1,0 ≤ y < 0.3, 0 ≤ z < 0.3, 0 < a < 0.2, 0 < b < 0.1, 0 < c < 0.1, 0 ≤ d < 0.1, x + y + z + b + c + d = 1, and optionally, 0.8 ≤ x < 1; step S2: mixing and sintering a Co-containing compound and the high-nickel ternary positive electrode material matrix doped with M1, M2, and optionally W to obtain a high-nickel ternary positive electrode material doped with Co ; and step S3: mixing and sintering an Al-containing compound, a B-containing compound, and the high-nickel ternary positive electrode material doped with Co to obtain a modified high-nickel ternary positive electrode material.
  2. The method according to claim 1, characterized in that the high-nickel ternary precursor is doped with W, in addition to an M1-containing compound, and an M2-containing compound.
  3. The method according to claim 1 or claim 2, characterized in that the high-nickel ternary positive electrode material is doped with Co in a surface layer and coated with a Co containing compound on a surface.
  4. The method according to claim 2 or claim 3, characterized in that in step S1, a sintering temperature is 700-950°C, a sintering duration is 10-20 h, and a sintering atmosphere is air or O 2 .
  5. The method according to claim 4, characterized in that a particle size of the Co-containing compound is 0.001-10 µm, optionally 0.001-1 µm.
  6. The method according to any one of claims 2 to 5, characterized in that in step S2, a sintering temperature is 500-800°C, optionally 550-750°C; a sintering duration is 5-15 h, optionally 5-10 h; and a sintering atmosphere is air or O 2 .
  7. The method according to any one of claims 2 to 6, characterized in that in step S3, a sintering temperature is 200-500°C, optionally 200-400°C; a sintering duration is 5-15 h, optionally 5-10 h; and a sintering atmosphere is air or O 2 .
  8. A modified high-nickel ternary positive electrode material made by the method of any of claims 1 to 7.
  9. A secondary battery, comprising a modified high-nickel ternary positive electrode material made according to any one of claims 1 to 7.
  10. A battery module, comprising the secondary battery according to claim 9.
  11. A battery pack, comprising the battery module according to claim 10.
  12. An electric apparatus, comprising at least one of the secondary battery according to claim 9, the battery module according to claim 10, and the battery pack according to claim 11.

Description

TECHNICAL FIELD This application relates to the field of lithium battery technologies, and in particular, to a modified high-nickel ternary positive electrode material and a preparation method therefor, a secondary battery, a battery module, a battery pack, and an electric apparatus. BACKGROUND With the rapid development of the new energy field, lithium-ion secondary batteries, by virtue of their excellent electrochemical performance, zero memory effect, and little environmental pollution, are widely used in all kinds of large power apparatuses, energy storage systems, and consumer products, especially the field of new energy vehicles such as battery electric vehicles and hybrid electric vehicles. Due to great development of the lithium-ion secondary batteries, higher requirements are imposed on energy density, cycling performance, safety performance, and the like of the lithium-ion secondary batteries, while high-nickel positive electrode active materials are considered as the optimal choice to meet the requirements for high energy density. However, with continuously increasing of nickel content, structural stability of the high-nickel positive electrode active materials become worse, thus affecting the cycling performance and storage performance of the lithium-ion secondary batteries. Therefore, there is a need to increase the capacity of the lithium-ion secondary batteries while ensuring the cycling performance and storage performance of the secondary batteries. SUMMARY In view of the technical problem in the background, this application provides a modified high-nickel ternary positive electrode material, so that a lithium-ion battery prepared using the material has improved cycling performance and storage performance while having a high capacity. To achieve the foregoing objective, a first aspect of this application provides a modified high-nickel ternary positive electrode material, including an inner core, an inner coating layer, and an outer coating layer, where the inner core includes a high-nickel ternary positive electrode material matrix, the matrix being doped with M1, M2, and W, where M1 is one of Mo, Zr, Ti, Sb, Nb, and Te, M2 is one of Mg, Al, Ca, Zn, and Sr, and a chemical formula of the high-nickel ternary positive electrode material matrix doped with M1, M2, and W is Li1+a[NixCoyMnzM1bM2cWd]O2, where 0.65 ≤ x < 1, 0 ≤ y < 0.3, 0 ≤ z < 0.3, 0 < a < 0.2, 0 < b < 0.1, 0 < c < 0.1, 0 < d < 0.1, x + y + z + b + c + d = 1, and optionally, 0.8 ≤ x < 1; a surface layer of the inner core is also doped with Co; the inner coating layer is a Co-containing compound; and the outer coating layer includes an Al-containing compound and a B-containing compound. Compared with the prior art, this application includes at least the following beneficial effects: In this application, the high-nickel ternary positive electrode material matrix is doped with three kinds of ions (namely M1, M2, and W) synergistically, so that structural stability of the high-nickel ternary positive electrode material can be more effectively increased, thereby significantly improving cycling performance and thermal stability of the secondary battery. In this application, the surface layer of the high-nickel ternary positive electrode material is also doped with Co, so that an amount of high-valent nickel ions contained in the surface layer of the high-nickel ternary positive electrode material can be effectively reduced, thereby reducing side reactions between the high-valent nickel ions and the electrolyte and further improving the cycling performance and storage performance of the secondary battery. In addition, in this application, the high-nickel ternary positive electrode material is uniformly coated with an inner layer containing a Co compound and an outer layer containing an Al compound and a B-containing compound, so that an amount of lithium impurities contained on the surface can be effectively reduced and interface side reactions between the high-nickel ternary positive electrode material and the electrolyte can be further effectively inhibited, thereby improving the capacity and rate performance of the high-nickel ternary positive electrode material and further improving the cycling, storage, and safety performance of the secondary battery. In any embodiment, a doping amount of M1 is ≥ a doping amount of M2 or W. In any embodiment, a ratio of the doping amount of M1 to a sum of the doping amounts of M2 and W is 1:(0.1-2), optionally 1:(0.5-1.5). The ratio of the doping amount of M1 to the sum of the doping amounts of M2 and W being controlled within the given range can ensure that the high-nickel ternary positive electrode material has a relatively high capacity and can improve structural stability of the material to the greatest extent, thereby further improving the cycling performance of the secondary battery. In any embodiment, a thickness d of the surface layer satisfies 0 < d < 3 µm, optionally 0 < d < 2 µm. When the