Positive electrode active material for lithium ion battery, positive electrode material for lithium ion battery, positive electrode for lithium ion battery, lithium ion battery, and method for producing positive electrode active material for lithium ion battery

摘要

PROBLEM TO BE SOLVED: To provide a sulfide-based positive active material for a lithium ion battery, having an excellent initial discharging capacity.SOLUTION: A positive active material for a lithium ion battery includes Li, S, and Cu as constituent elements. The positive active material has a crystal structure showing a diffraction spectrum that has diffraction peaks within ranges of diffraction angles, 2=26-28°, 44-46°, and 52-54°, and no diffraction peak within ranges of the diffraction angles, 2=30-32° and 55-57°, when an X-ray diffraction analysis is performed by using CuK rays as a radiation source.