| 摘要 |
PROBLEM TO BE SOLVED: To prevent generation of gas in the formation of a solid electrolyte film by reaction with lithium ions, to prevent deformation in the appearance of a battery in charging, and to obtain a long cycle life of the battery by adding a gas additive having a reduction potential higher than that of a nonaqueous organic solvent to the nonaqueous organic solvent. SOLUTION: The gas additive preferably has a reduction potential of +0.5 to 3.5 V vs. the potential of a lithium ion. As a practical gas additive, SO2, CO2, N2O can be used, and the adding amount is preferably 20 wt.% or less. The nonaqueous organic solvent is preferably selected from ethylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, propylene carbonate, or a mixture of them. A supporting electrolyte salt of an electrolyte of a lithium secondary battery can be selected from lithium hexafluorophosphate, lithium tetrafluoroborate, or the like. |
