POSITIVE ELECTRODE ACTIVE MATERIAL FOR NONAQUEOUS ELECTROLYTE SECONDARY BATTERY, METHOD FOR PRODUCING SAME, AND NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

摘要

Disclosed is a positive electrode active material for a nonaqueous electrolyte secondary battery, which contains complex oxide particles containing lithium, nickel, and an element M that is either aluminum and/or cobalt. The complex oxide particles contain primary particles in each of which the content ratio of the element M in the surface layer portion is higher than the content ratio of the element M in the inner portion, and the ratio of the primary particles relative to all the complex oxide particles is 80-100% by weight. The positive electrode active material for a nonaqueous electrolyte secondary battery has excellent cycle characteristics and storage characteristics, and is suitable for use in a wide range of charge state or use in a high temperature environment. Also disclosed is a nonaqueous electrolyte secondary battery which uses the positive electrode active material for a nonaqueous electrolyte secondary battery.