Gradient single-crystal positive electrode material, and preparation method therefor and use thereof

Abstract

The present disclosure discloses a gradient single-crystal positive electrode material, which has a chemical formula of LiNixCoyA1-x-yO2@mLiaZbOc, wherein 0<x<1, 0<y<1, 0<x+y<1, 0<m<0.05, 0.3<a≤10, 1≤b<4, and 1≤c<15, A is at least one of Mn, Zr, Sr, Ba, W, Ti, Al, Mg, Y, and Nb, and Z is at least one of B, Al, Co, W, Ti, Zr, and Si. The atomic ratio of the content of Co on the surface of the single-crystal positive electrode material particle to the content of Ni+Co+A on the surface is greater than 0.4 and less than 0.8, and the atomic ratio of Co at a depth 10% of the radius from the surface of the single crystal positive electrode material particle is not less than 0.3; and the single-crystal positive electrode material particle has a roundness of greater than 0.4, and is free from sharp corners.

Dependencies are inferred from the claim text.