Non-aqueous electrolyte and electricity storage device using same

A nonaqueous electrolytic solution of an electrolyte salt dissolved in a nonaqueous solvent, which comprises from 0.001 to 10% by mass of a compound of formula (II):

• wherein
• Y is a group —C(═O)— or a group —S(═O)2—;
• R1 and R2 are each independently a hydrogen atom, a halogen atom, or an alkyl group having from 1 to 4 carbon atoms;
• and
• A is a cycloalkanediyl group having from 5 to 12 carbon atoms or a benzenediyl group, which may have a substituent.

A nonaqueous electrolytic solution of an electrolyte salt dissolved in a nonaqueous solvent, which comprises from 0.001 to 10% by mass of a compound of formula (III):

• wherein
• Y is a group —C(═O)— or a group —S(═O)2—;
• R21 and R22 are each independently a halogenoalkyl group having from 1 to 4 carbon atoms;
• X21 and X22 are each independently a halogen atom;
• L is a divalent linking group having from 1 to 6 carbon atoms and optionally substituted with a halogen atom;
• and
• m, n, p and q are each independently an integer of from 0 to 5, satisfying 1≦m+n≦5 and 1≦p+q≦5.

A cycloalkanedisulfonate compound of formula (II-1):

• wherein
• R33 and R34 are each independently a hydrogen atom, a halogen atom, or an alkyl group having from 1 to 4 carbon atoms;
• and
• R5 to R14 are each independently a hydrogen atom, an alkyl group having from 1 to 6 carbon atoms, an alkenyl group having from 2 to 6 carbon atoms, an alkynyl group having from 2 to 6 carbon atoms, an aryl group having from 6 to 12 carbon atoms, or an alkoxy group having from 1 to 6 carbon atoms, wherein R5 to R14 may bond to each other to form a ring structure, and a hydrogen atom thereof may be substituted with a halogen atom;
• and n is an integer of from 0 to 3.

An alkanedisulfonate compound of formula (III-1):

• wherein
• R23 and R24 are each independently a fluoroalkyl group having from 1 to 4 carbon atoms;
• L is a divalent linking group having from 1 to 6 carbon atoms and optionally substituted with a halogen atom;
• and
• m, n, p and q are each independently an integer of from 0 to 5, satisfying 1≦m+n≦5 and 1≦p+q≦5.