POSITIVE ELECTRODE ACTIVE MATERIAL, POSITIVE ELECTRODE, AND NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

The positive electrode active material disclosed here includes: first lithium composite oxide particles in the form of single particles; and second lithium composite oxide particles in the form of secondary particles. When in a volume-based particle size distribution obtained by a laser diffraction scattering method, a 10%-particle size (D) is a particle size with a cumulative frequency of 10%, a 50%-particle size (D) is a particle size with a cumulative frequency of 50%, and a 90%-particle size (D) is a particle size with a cumulative frequency of 90%, a 50%-particle size of the second lithium composite oxide particles is larger than that of the first lithium composite oxide particles, and a particle size distribution width of the second lithium composite oxide particles expressed by (D-D)/D is 0.50 to 0.65.