| 摘要 |
PROBLEM TO BE SOLVED: To provide an active material for a nonaqueous electrolyte secondary battery which is large in discharge capacity and excellent in charge/discharge cycle performance.SOLUTION: An active material for a nonaqueous electrolyte secondary battery contains lithium transition metal composite oxide having a hexagonal structure. The lithium transition metal composite oxide contains Li and a transition metal element Me including Co, Ni and Mn. A molar ratio Li/Me of Li with respect to the whole transition metal element Me is 1.25-1.60, a molar ratio Co/Me of Co in the whole transition metal element Me is 0.02-0.23, and a molar ratio Mn/Me of Mn in the whole transition metal element Me is 0.63-0.72. The lithium transition metal composite oxide is observed as a single phase of a hexagonal structure on an X-ray diffraction diagram when electrochemically oxidized up to a potential of 4.8 V(vs.Li/Li). |
