POSITIVE ELECTRODE ACTIVE MATERIAL, AND LITHIUM SECONDARY BATTERY COMPRISING SAME

摘要

The present invention relates to a positive electrode active material and to a secondary battery comprising same. The positive electrode active material comprises lithium manganese oxide (A) having a spinel crystal structure, and two or more kinds of lithium nickel-manganese-cobalt composite oxides (B) which simultaneously contain Ni, Mn and Co as transition metals. The lithium nickel-manganese-cobalt composite oxides (B) are selected from a group consisting of element composition, particle size, and density, and at least one of the composite oxides is different from the others.