Multi-element cathode material and preparation method thereof, lithium-ion battery

A lithium ion battery, comprising a multi-element cathode material, wherein:

• a surface of the multi-element cathode material comprises a dot-like coating and/or an island-like coating;
• a particle diameter D1 with 1% cumulative particle size distribution of the multi-element cathode material is greater than or equal to 0.7 μm;
• an arithmetic average roughness Ra, measured with a three-dimensional scanning electron microscope, of the coating of the multi-element cathode material satisfies 20 nm≤Ra≤200 nm;
• and
• a coverage Q of the dot-like coating and/or the island-like coating of the multi-element cathode material satisfies 3%≤Q≤30%,
• a matrix of the cathode material has a composition represented by a formula I:
• LiaNixMnyCozMbO2 the formula I,
• where 0.9≤a≤1.1, 0.5<x<1, 0<y<0.5, 0<z<0.5, and 0≤b≤0.02;
• the coating comprises a lithium oxide compound containing an element J and/or an oxide containing the element J;
• wherein contents of the matrix and the coating enable the cathode material to satisfy 0<[n(J)]/[n(Ni)+n(Co)+n(Mn)]<0.03;
• and
• wherein M and J are each independently selected from at least one element of Ba, Ra, Zr, Fe, Ca, Zn, B, W, Nb, Cd, Pb, Si, Mo, Cu, V, Ta, Cr, La, Al, Ce, Er, Ho, Y, Mg, Sr, and Ti.