CATHODE ACTIVE MATERIAL AND LITHIUM SECONDARY BATTERY EMPLOYED WITH THE SAME

摘要

PURPOSE: A positive electrode active material is provided to obtain safety of a lithium secondary battery and to provide excellent life time, power performance, and low temperature performance by comprising lithium manganese oxide and two or more kinds of lithium nickel-manganese-cobalt composite oxides. CONSTITUTION: A positive electrode active material for a secondary battery comprises: lithium manganese oxide of spinel crystal structure, and two or more kinds of lithium nickel-manganese-cobalt composite oxides simultaneously comprising Ni, Mn and Co as transition metals. The mixing ratio of the lithium manganese oxide and the lithium nickel-manganese-cobalt composite oxides is 30-90:70-10 based on weight ratio.