Positive active material, positive electrode plate, electrochemical energy storage apparatus, and apparatus

A method for preparing a positive active material, the method comprising:

• mixing a ternary material precursor comprising Ni, Co, and M, a Li-containing compound, and a compound containing a doping element Me to form a precursor mixture;
• sintering the precursor mixture to form secondary particles;
• performing graded screening of the secondary particles;
• and
• obtaining the secondary particles having a particle size Dv10 from 2.5 μm to 8 μm, wherein Dv10 is a corresponding particle size when a cumulative volume distribution percentage of the positive active material reaches 10%,
• wherein the secondary particles have a formular of LixNiyCozMkMepOr or LixNiyCozMkMepOr, 0.85≤x≤1.15, 0<y<1, 0<z<1, 0<k<1, 0≤p≤0.1, 1≤r≤2, M is one or two selected from Mn and Al, Me is one or more selected from Zr, Zn, Cu, Cr, Mg, Fe, V, Ti, Sr, Sb, Y, W, and Nb.

A method for preparing a positive active material, the method comprising:

• mixing a ternary material precursor comprising Ni, Co, and M, a Li-containing compound, and a compound containing a doping element Me to form a precursor mixture;
• sintering the precursor mixture to form secondary particles;
• mixing the secondary particles with a compound containing a coating element to form a mixture;
• sintering the mixture to form the positive active material, wherein the positive active material comprises a coating layer on a surface of at least one of the secondary particles, and the coating layer comprises the coating element;
• performing graded screening of the positive active material;
• and
• obtaining the positive active material having a particle size Dv10 from 2.5 μm to 8 μm, wherein Dv10 is a corresponding particle size when a cumulative volume distribution percentage of the positive active material reaches 10%.