CATHODE ACTIVE MATERIAL FOR LITHIUM SECONDARY BATTERY

摘要

PURPOSE: A positive electrode active material for a lithium secondary battery is provided to form a more uniform and stable layered structure and to ensure overall improvement in electrochemical characteristics containing a battery capacity, and particularly, improvement in high rate charge and discharge characteristics. CONSTITUTION: A positive electrode active material for a lithium secondary battery, wherein the positive electrode active material is a lithium transitional metal oxide having a a-NaFeO2 layered crystal structure, wherein the transitional metal contains a Ni-Mn mixed transitional metal, the average oxidation state of the whole transitional metal excluding lithium is larger than trivalence, and the transitional metal satisfies the following formulas 1: 1.0 < m(Ni)/m(Mn) and 2: m(Ni^2+)/m(Mn^4+) < 1.