METHOD FOR PREPARING CATHODE ACTIVE MATERIAL PRECURSOR FOR LITHIUM SECONDARY BATTERY, AND CATHODE ACTIVE MATERIAL PRECURSOR PREPARED BY PREPARATION METHOD

The present invention provides a method for preparing a cathode active material precursor, a cathode active material precursor prepared by the preparation method, and a cathode for a secondary battery and a lithium secondary battery, which comprise same, the method comprising: a first step of injecting, into a reactor, a metal additive comprising at least one element selected from the group consisting of group 5 elements and group 6 elements; and a second step of injecting, into the reactor, a transition metal aqueous solution containing a nickel raw material, a cobalt raw material and a manganese raw material, a solution containing ammonium ions, and a basic aqueous solution, and performing a coprecipitation reaction, thereby preparing a cathode active material precursor having an average diameter (D50) of 3-5 µm.