COMPOSITE COATED MODIFIED HIGH-NICKEL NCA POSITIVE ELECTRODE MATERIAL AND PREPARATION METHOD THEREFOR

Provided in the present invention is a composite coated modified high-nickel NCA positive electrode material and a preparation method therefor. The NCA positive electrode material has a ternary material as a matrix, and the surface of the matrix is coated with a composite coating modifying layer composed of LiCoO2 and Co2O3. The preparation method comprises: subjecting a nickel salt solution, a cobalt salt solution, a sodium hydroxide solution and an ammonia water solution to a co-precipitation reaction to obtain a nickel-cobalt hydroxide precursor; uniformly mixing the resulting nickel-cobalt hydroxide precursor with a lithium source and an M source, then sintering same in an oxygen atmosphere, then cooling same to room temperature, and crushing and sieving same to obtain a primary sintered matrix; and mixing the resulting primary sintered matrix with deionized water, adding a cobalt source, adjusting the pH value, then filtering and drying same, placing same in an oxygen atmosphere for repeated heating and