Ternary cathode material precursor, preparation method and application thereof

The invention provides a ternary cathode material precursor, a preparation method and an application thereof. The method comprises the following steps: firstly, preparing a mixed metal salt solution, and adjusting the pH value to be 0.1-5.0; removing impurities through an exchange column filled with cation exchange resin; and finally pumping the obtained material, a complexing agent and a precipitant into a coprecipitation reaction kettle simultaneously, and synthesizing a high-quality ternary cathode material precursor with extremely low impurity content through a controlled crystallization method, wherein the chemical formula of the precursor is NixCoyMnz(OH)2; x is less than 1 and greater than or equal to 0.3; y is less than or equal to 0.5 and greater than or equal to 0.05; and x+y+z is equal to 1. Through removing impurities from the mixed metal salt solution, the impurity content in the ternary cathode material precursor is greatly reduced; and the safety performance and the electrochemical property of the ternary cathode material are improved.