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

摘要

The present invention provides a cathode active material, a method for preparing the same, and a lithium secondary battery comprising the same, the cathode active material being prepared by a method comprising the steps of: mixing a precursor of a metal for a cathode active material with nanosol of a ceramic ionic conductor, and adsorbing the nanosol of the ceramic ionic conductor onto the surface of the precursor; and mixing a lithium raw material with the precursor onto which the nanosol of the ceramic ionic conductor is adsorbed, and subjecting the mixture to a heat treatment, thereby preparing a cathode active material comprising lithium complex metal oxide particles, wherein a lithium complex metal oxide that is present on the surface side of the lithium complex metal oxide particles is doped with a metallic element of the ceramic ionic conductor. Since the lithium complex metal oxide that is present on the surface is uniformly doped with the metallic element constituting the ceramic ionic conductor, the structural stability is significantly increased and, accordingly the capacity, rate characteristics and cycle characteristics of a battery can be significantly improved.