| 摘要 |
PROBLEM TO BE SOLVED: To provide a nonaqueous secondary battery having high capacity, high safety during overcharge while maintaining superior property in highly efficient discharge, and superior cycle property. SOLUTION: The nonaqueous secondary battery uses as a positive electrode active material a metal oxide capable of storing/releasing Li ions, as a negative electrode active material artificial graphite having a BET specific surface area of 3 m<2> /g or more, a (002) spacing d002 of 0.3375 nm or less as measured by X-ray diffraction, and a crystalite size Lc of 40 nm or more in a c-axial direction, and formed into graphite by baking another material than mesophase carbon, and a nonaqueous electrolyte containing a compound having alkyl groups bonded to benzene rings and sulfide compound. The content of the compound having the alkyl groups bonded to the benzene rings in the nonaqueous electrolyte is preferably 1-10% and the content of the sulfide compound is preferably 0.01-1%. |
