High-nickel positive electrode active material, preparation method thereof, and lithium-ion battery, battery module, battery pack and power consuming device comprising same

A method for preparing a high-nickel positive electrode active material, comprising:

• coating a high-nickel ternary precursor with a silicon-aluminum hydroxide to obtain a first intermediate;
• mixing and sintering the first intermediate and an M precursor and a lithium precursor to obtain a second intermediate;
• and
• mixing and sintering the second intermediate and an R precursor to obtain the high-nickel positive electrode active material;
• wherein the high-nickel positive electrode active material is a core-shell structure,
• the core comprises Li1+a[NixCoyMnzMb]O2, wherein 0.6≤x<1, 0<y<0.3, 0<z<0.3, 0<a<0.2, 0<b<0.2, x+y+z+b=1, M being Sb;
• the shell comprises a first shell layer coating the core, a second shell layer coating the first shell layer, and a transition layer formed between the first shell layer and the second shell layer;
• wherein
• the first shell layer is a fast ionic conductor consisting of four elements of lithium, aluminum, silicon and oxygen;
• and
• the second shell layer comprises an oxide of an element R, the element R being selected from at least one of B, Ti, P, or La;
• and
• the transition layer comprises LiBO2.

A high-nickel positive electrode active material with a core-shell structure, wherein

• the core comprises Li1+a[NixCoyMnzMb]O2, wherein 0.6≤x<1, 0<y<0.3, 0<z<0.3, 0<a<0.2, 0<b<0.2, x+y+z+b=1, M being Sb;
• the shell comprises a first shell layer coating the core, a second shell layer coating the first shell layer, and a transition layer formed between the first shell layer and the second shell layer;
• wherein
• the first shell layer is a fast ionic conductor consisting of four elements of lithium, aluminum, silicon and oxygen;
• the second shell layer comprises an oxide of an element R and a hydroxide Co(OH)2, the element R being Co;
• and
• the transition layer comprises LiBO2.