| 摘要 |
PROBLEM TO BE SOLVED: To provide a lithium secondary battery stable in a charged state by using an inexpensive manganese base material as a positive active material of the lithium secondary battery. SOLUTION: A lithium secondary battery is constituted with a positive electrode, a negative electrode, a nonaqueous electrolyte in which a lithium electrolyte is dissolved, and a separator. After assembling, the battery is continuously charged and discharged at least one cycle to retard the dissolution of a positive active material into the nonaqueous electrolyte, and charge/discharge characteristics are stabilized. The current density in charge/discharge is limited to 0.01 mA/mg (the positive active material) or more. As the positive active material, a Mn base oxide, especially a spinel Mn oxide obtained by substituting part of Mn atoms with lithium and/or transition metal element M, represented by the composition formula, Li(1+x)MyMn(2-x-y)O4. (In the formula, M shows at least one of transition metal elements such as Fe, Cr, Co and Ni and 0<=x<=0.33 and 0<=y<=1). |
