NONAQUEOUS ELECTROLYTE SOLUTION, ELECTROCHEMICAL ENERGY STORAGE DEVICE USING SAME, AND NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

摘要

Disclosed is a nonaqueous electrolyte solution containing 1,2-dialkoxyethane (A) represented by the following formula: R-O-CH₂-CH₂-O-R' (wherein R and R' may be the same as or different from each other and respectively represent an unsubstituted or fluorine-substituted alkyl group having 3 or less carbon atoms) and lithium bis(trifluoromethansulfonyl)imide (B) at a molar ratio (A)/(B) of not less than 0.75 but not more than 2. This nonaqueous electrolyte solution is in a liquid state at room temperature.