NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

摘要

The purpose of the present invention is to provide a nonaqueous electrolyte secondary battery that has improved cycle characteristics by improving a positive electrode active material for nonaqueous electrolyte secondary batteries in cases where particles, which are obtained by aggregating primary particles so as to form secondary particles, are used as the positive electrode active material, said nonaqueous electrolyte secondary battery thereby being suitable for use as a power supply for hybrid electric vehicles, or the like. The nonaqueous electrolyte secondary battery is characterized in that: the positive electrode active material is composed of secondary particles (20) that are obtained by aggregating primary particles (21); the primary particles (21) have an aspect ratio of from 2.0 to 10.0 (inclusive); and when the half width of a 110 diffraction peak having a diffraction angle 2? within the range of 64.5° ± 1.0° in a powder X-ray diffraction measurement using a CuKa ray is represented by FWHM110, the following relation 0.10° = FWHM110 = 0.30° is satisfied.