PRECURSOR FOR CATHODE ACTIVE MATERIAL AND PREPARATION METHOD THEREFOR

The present invention relates to a method of preparing a precursor for a positive electrode active material which includes a seed forming step of forming precursor seeds for a positive electrode active material by performing a co-precipitation reaction while supplying a transition metal aqueous solution, an ammonium cationic complexing agent, and a basic compound to a reactor, and a particle growing step of growing precursor particles for a positive electrode active material by performing a co-precipitation reaction while supplying a transition metal aqueous solution, an ammonium cationic complexing agent, and a basic compound to a reaction solution in which the precursor seeds for a positive electrode active material have been formed, wherein the reaction proceeds while continuously increasing feed rates of the transition metal aqueous solution and the ammonium cationic complexing agent in the particle growing step.