| 摘要 |
PROBLEM TO BE SOLVED: To impart excellent flame resistance and keep satisfactory battery performance over a long period by limiting the gamma-butyrolactone contained in the nonaqueous solvent of a gel electrolyte to a specified value or less. SOLUTION: This battery has positive electrode, a negative electrode and a gel electrolyte consisting of a polymer material containing polyacrylonitrile and an electrolytic salt mainly composed of a nonaqueous solvent containing gamma-butyrolactone and LiPF6 . The content of gamma-butyrolactone in the nonaqueous solvent is set to 30 mole % or less. The nonaqueous solvent is a mixed solvent of gamma-butyrolactone and ethylene carbonate. This gel electrolyte is prevented from taking fire by the carbonizing effect of the polymer material and the carbonization acceleration of LiPF6 when it makes contact with a flame. Since the gamma-butyrolactone is contained in the nonaqueous solvent in a ratio of 30 mole % or less, high ion conductivity can be provided, and the chemical stability is also enhanced. |
