POSITIVE ELECTRODE ACTIVE MATERIAL, METHOD FOR PREPARING SAME, AND POSITIVE ELECTRODE AND LITHIUM SECONDARY BATTERY COMPRISING SAME

A positive electrode active material according to the present invention is a positive electrode active material including a lithium nickel-based oxide particle in the form of a single particle which is composed of one single nodule, or a pseudo-single particle which is a composite of 30 or fewer nodules, and a coating layer formed on the surface of the lithium nickel-based oxide particle and including cobalt, wherein when the positive electrode active material is analyzed by X-ray photoelectron spectroscopy (XPS), XPS (Co/Ni), which is an atomic ratio of Co to Ni, is 0.15 or greater, when the positive electrode active material is analyzed by Auger electron spectroscopy (AES), AES (Co/Ni), which is a standard deviation of the atomic ratio of Co to Ni, is 0.80 or less, and the positive electrode active material has a content of residual LiCO of 0.50 wt% or less.