| 摘要 |
PROBLEM TO BE SOLVED: To provide a lithium-ion secondary battery which has a high capacity retention rate in a charge/discharge cycle.SOLUTION: A lithium-iron-manganese-based composite oxide has a layered rock-salt structure, is represented by formula (1) LiMMnMFeO(where 1.05≤x≤1.32, 0.33≤y≤0.63, 0.06≤z≤0.50, 0<p≤0.63, 0.06≤q≤0.50, 0≤δ≤0.80, y≥p, and z≥q are satisfied; Mis at least one element of Ti and Zr; and Mis at least one element selected from the group consisting of Co, Ni, and Mn), and has been reduced by being mixed with organic matter and fired. |
