POSITIVE ACTIVE MATERIAL FOR LITHIUM-ION SECONDARY BATTERY, POSITIVE ELECTRODE FOR LITHIUM-ION SECONDARY BATTERY, AND LITHIUM-ION SECONDARY BATTERY

摘要

The present invention provides a positive electrode active material for a lithium ion secondary battery, a positive electrode for a lithium ion secondary battery, and a lithium ion secondary battery. The positive electrode active material for a lithium ion secondary battery comprises lithium composite oxide particles containing nickel, manganese and fluorine. The lithium composite oxide particles comprise: a particle center unit; and a surface layer unit which is near to a surface of the lithium composite oxide particles in comparison with the particle center unit. A fluorine atom concentration of the particle center unit {Fe (at%)} measured by energy-dispersive X-ray spectroscopy is lower than a fluorine atom concentration of the surface layer unit {Fs (at%)}.