A non-aqueous electrolyte solution including a lithium salt, a non-aqueous solvent, a cyclic carbonate compound having an unsaturated bond and a compound of formula R21—S(O)2—F in which R2 is an alkyl group having from 1 to 12 carbon atoms that may be substituted by a fluorine atom or an alkenyl group having from 2 to 12 carbon atoms that may be substituted by a fluorine atom, and the alkyl group or alkenyl group may have an ether linkage within its chain.