Lithium nickel manganese cobalt oxide high-nickel single-crystal positive electrode material and preparation method therefor

A method for preparing a lithium nickel manganese cobalt oxide high-nickel single-crystal positive electrode material, wherein the method comprises the following steps:

• mixing and ball milling nickel cobalt manganese hydroxide with a LiOH·H2O, zirconium oxide, tungsten oxide and sodium carbonate, then performing primary sintering, pulverizing and then obtaining a lithium nickel manganese cobalt oxide high-nickel single-crystal positive electrode material intermediate, wherein:
• a molar ratio of the nickel cobalt manganese hydroxide to zirconium oxide, tungsten oxide, and sodium carbonate is 1:0.002:0.0016:0.002, the chemical composition of the nickel cobalt manganese hydroxide is Ni0.80Co0.10Mn0.10(OH)2;
• a molar ratio of the nickel cobalt manganese hydroxide to lithium in the LiOH·H2O is 1:1.05, and the temperature of the primary sintering is 950° C., a time of the primary sintering is 15 h;
• evenly mixing the lithium nickel manganese cobalt oxide high-nickel single-crystal positive electrode material intermediate and a coating agent, and then performing secondary sintering to obtain a lithium nickel manganese cobalt oxide high-nickel single-crystal positive electrode material, wherein the coating agent is Y2O3;
• the amount of the coating agent added is 0.05 wt % to 5 wt % of the total amount of the lithium nickel manganese cobalt oxide high-nickel single-crystal positive electrode material intermediate;
• a temperature of the secondary sintering is 500° C., a time of the secondary sintering is in a range from 10 h.