| 摘要 |
PROBLEM TO BE SOLVED: To improve charging/discharging cycle characteristics, by stabilizing a crystal structure of a positive electrode active material mainly composed of a lithium-manganese composite oxide. SOLUTION: At least, either one of Na, an Na compound, and an ammonium compound, is added to LiMn2 O4 as additive. These additives, by their being mixed with the LiMn2 O4 merely physically or, at least, part of them existing in a state that they are taken in a crystalline structure of the LiMn2 O4 , facilitate movement of Li ions or suppress elution of Mn. Sulfate is particularly preferable as the Na compound and as the ammonium compound. |
