| 摘要 |
PROBLEM TO BE SOLVED: To improve the electrochemical characteristic of a nonaqueous electrolyte secondary battery which uses a spinel type lithium manganese oxide as its positive electrode active material, particularly to improve the battery in capacity degradation due to a cycle, while maintaining a high capacity. SOLUTION: A lithium secondary battery uses as the active material of its positive electrode a spinel type lithium manganese oxide represented by the formula. Where, δ is the amount of deficiency of oxygen, M is at least one kind of metal element having a valence of 1 to 3.0<=δ<=0.01, and 0.01<y<=0.20. When the average valence of Mn in its initial condition is dented as (a) and the average valence of the metal M is denoted as (b), a=(7-2δ-y-bx)/(2-x). And the spinel type lithium manganese oxide satisfies the formula, 3.501<=a<=3.535. |
