Coated nickel-rich ternary material, preparation method and application thereof

A coated nickel-rich ternary material, wherein the coated nickel-rich ternary material has a chemical formula of LiNixCoyMnzO2·a[M3(PO4)2·bH2O], wherein 0.6≤x≤0.8, 0.1≤y≤0.2, 0.1≤z≤0.2, x+y+z=1, 0.01≤a≤0.03, 3≤b≤8;

• said M3(PO4)2·bH2O is at least one selected from the group consisting of nickel phosphate, cobalt phosphate and manganese phosphate;
• the coated nickel-rich ternary material has a flower-like structure, and is a phosphate-coated nickel-rich ternary material;
• and a method for preparing the coated nickel-rich ternary material comprises the following steps:
• (1) dissolving a nickel source, a cobalt source, and a manganese source in a solvent to obtain solution A, adding and mixing a surfactant with the solution A to obtain solution B, wherein the nickel source is at least one selected from the group consisting of a sulfate of nickel, a nitrate of nickel, and an acetate of nickel;
• the cobalt source is at least one selected from the group consisting of a sulfate of cobalt, a nitrate of cobalt, and an acetate of cobalt;
• the manganese source is at least one selected from the group consisting of a sulfate of manganese, a nitrate of manganese, and an acetate of manganese;
• (2) mixing a solution of a phosphate salt with the solution B to obtain a mixture, subjecting the mixture to a microwave hydrothermal treatment to obtain precipitate C, wherein the microwave hydrothermal treatment is carried out at a temperature of 140° C.-220° C. for 10-20 minutes;
• (3) washing the precipitate C with water, followed by drying and grinding the precipitate C to obtain coated nickel-rich ternary precursor powder D;
• and
• (4) mixing the coated nickel-rich ternary precursor powder D with a lithium source to obtain a mixture, followed by subjecting the mixture to calcinating, grinding and screening to obtain the coated nickel-rich ternary material.