Preparation method of synergistically modified ternary positive electrode material

The invention discloses a preparation method of a synergistically modified ternary positive electrode material, and the method comprises the following steps: step 1, liquid phase coating: step 1, dissolving a tantalum source in absolute ethyl alcohol and stirring, and then adding a ternary material for stirring and ultrasonic treatment; step 1 and step 2, slowly dropwise adding deionized water for hydrolysis; step 1-3, adding a lithium-containing solution after sufficient hydrolysis, and heating and stirring until ethanol is completely volatilized; step four, carrying out vacuum drying on the obtained solid powder; and 2, high-temperature heat treatment: taking the solid powder subjected to vacuum drying, carrying out high-temperature heat treatment in a tubular furnace, and cooling to obtain the modified ternary positive electrode material. Through grain boundary modification, surface coating and bulk phase doping, the performance is greatly improved, and the problem that traditional grain boundary modificat