| 摘要 |
PROBLEM TO BE SOLVED: To restrain the reduction in battery capacity and control the activity of a positive electrode surface to improve the cycle life by further including carbon and fluorine in a composite oxide containing lithium, transition metal and oxygen. SOLUTION: As the composite oxide containing lithium, transition metal and oxygen to be used for a positive electrode active material for nonaqueous secondary battery, any composition, if usable for a positive electrode of nonaqueous secondary battery, can be used without particular limitation. As the transition metal, one or two or more selected from the group consisting of cobalt, manganese and nickel are preferable. Examples of the composite oxide composition for introducing carbon and fluorine include LiCoO2 LiNiO2 or a composition in which each site of LiCoO2 or LiNiO2 is partially substituted by other elements. In the composite oxide in the positive electrode active material, the quantity of fluorine contained as essential component is preferably set to 100 ppm or more to the total quantity of the composite oxide, particularly, 300 ppm or more and, more particularly, 1000 ppm or more. |
