Lithium cobalt based composite oxide with excellent life characteristics and positive electrode active material for secondary battery containing the same

摘要

The present invention includes lithium, cobalt, and manganese, and is a lithium-cobalt composite oxide represented by the following chemical formula 1, which is an O3 phase in a state of charge (SOC) of 50% or more of the theoretical capacity. The present invention relates to a lithium cobalt-based composite oxide characterized by maintaining a single phase crystal structure of (O3 phase). LixCo1-y-zMnyAzO2 (1) In the above formula, 0.95 ≦ x ≦ 1.15, 0 y ≦ 0.3, 0 ≦ z ≦ 0.2, and A is Al, Mg, Ti, Zr One or more elements selected from the group consisting of Sr, W, Nb, Mo, Ga, and Ni.