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

A method for preparing a ternary single crystal positive electrode material, comprising the following steps:

• (1) mixing a ternary polycrystalline micropowder, raising a temperature, carrying out a primary sintering, and lowering the temperature to obtain an intermediate;
• (2) subjecting the intermediate to jet pulverization to obtain a single crystal material, washing the single crystal material with water, and centrifugally drying the single crystal material to obtain a material with a residual alkali content of less than 1500 ppm;
• and
• (3) adding a coating agent to the material, raising a temperature, carrying out a secondary sintering, and lowering the temperature to obtain the ternary single crystal positive electrode material;
• wherein the coating agent is at least one of an oxide, hydroxide and salt of a metal, or an oxide and fluoride of a non-metal, or a corresponding acid and salt of the non-metal;
• the metal is at least one of Al, Ce, Y, Zn, Si, Cr, Nb, Mg, La, Sr, Zr, Sn, Na, Ca, Sb, V, and W;
• and the non-metal is at least one of B, P, F, C, and S, with aluminum hydroxide being excluded;
• wherein in step (1), the ternary polycrystalline micropowder is an unqualified product produced by means of mechanical grinding of the ternary polycrystalline material during crushing, which is a by-product produced during crushing of the ternary polycrystalline material;
• and a chemical formula of the ternary polycrystalline micropowder is LiNixCoyMnzO2, with 0.5≤x≤0.95, 0≤y≤0.4, 0.05≤z≤0.4, and x+y+z=1.