| 摘要 |
PROBLEM TO BE SOLVED: To make a nonaqueous secondary battery have an initial capacity close to the theoretical capacity and reduce degradation of the capacity after many charge/discharge cycles, in the event that lithium is used as a negative electrode and a nonaqueous electrolyte containing a lithium salt is used. SOLUTION: In a method for manufacturing a positive electrode active material used in this battery, a spinel-structure composite compound, which is obtained such that a lithium compound and manganese carbonate having a specific surface area larger than 10 m<2> /g are mixed together and caused to react at least for an hour within a temperature range not lower than 350 deg.C and not higher than 680 deg.C, is heat-treated within a temperature range not lower than 730 deg.C and not higher than 900 deg.C. Thus, the positive electrode active material is obtained being a spinel-structure composite compound of lithium, manganese, and oxygen, wherein a mol ratio of the lithium to the manganese is within a range of Li/Mn=0.48 to 0.55, a true density is 4.05 g/cm<3> or more, and a lattice constant is 8.240 Å or less. |
