| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for simply measuring a quantity of manganese elution without a troublesome work for disassembling a secondary battery, etc. SOLUTION: A positive electrode active material for a nonaqueous system electrolyte secondary battery comprises a composite oxide of lithium and manganese expressed by formula LiMn2-yMyO4 (M are at least one or more kinds of metal elements. y is 0-1). In the method for evaluating the material, the second composite oxide, which is obtained by eliminating Li from the first composite oxide using a chemical process and expressed by formula Li1-xMn2-yMyO4 (x is more than 0 to 1), is dispersed in an arbitrary nonaqueous system electrolyte and the quantity of the eluting manganese in the nonaqueous system electrolyte is measured after the regular period has been passed. |
