Abstract: A non-aqueous electrolyte solution contains: as an electrolyte, LiN(FSO2)2; and as an additive, at least one selected from the group consisting of a boron atom-containing compound represented by the general formula (3): B(OR6)3, a carbon atom-containing compound represented by the general formula (4): C(?O)(R5)(OR6), a sulfur atom-containing compound represented by the general formula (5): {S(?O)2(R5)y}x(OR6)x(2-y), and a phosphorus atom-containing compound represented by the general formula (6): P(?O)(R5)y(OR6)2.

Abstract: A non-aqueous electrolyte solution contains a sulfonylimide compound represented by the general formula (1): LiN(R1SO2)(R2SO2) (wherein R1 and R2 are identical or different from each other and each represents a fluorine atom, an alkyl group having 1 to 6 carbon atoms, or a fluoroalkyl group having 1 to 6 carbon atoms) as an electrolyte salt, an electrolyte solution solvent, and at least one of carbon dioxide (CO2), carbon monoxide (CO), a bicarbonate ion (HCO3?), or a carbonate ion (CO32?) dissolved therein. The electrolyte solution solvent includes at least one selected from the group consisting of a carbonate solvent, a lactone solvent, an ether solvent, a nitrile solvent, and a chain ester solvent, and a total amount of the at least one of CO2, CO, HCO3?, or CO32? dissolved is 20 ppm by mass or more.