POSITIVE ELECTRODE ACTIVE SUBSTANCE FOR NONAQUEOUS ELECTROLYTE SECONDARY BATTERY, POSITIVE ELECTRODE FOR NONAQUEOUS ELECTROLYTE SECONDARY BATTERY, AND NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

This positive electrode active substance for a nonaqueous electrolyte secondary battery contains secondary particles that are aggregates of primary particles of a lithium transition metal oxide. The average particle diameter of the primary particles is within the range of 0.5 to 2 μm, the compressive breaking strength of the primary particles is 1,000 MPa or greater, and the crystallite diameter of the primary particles is within the range of 100 to 280 nm.