Patent ID: 7154737

Claim:
A nonaqueous electrolyte characterized by containing: an ionic liquid which has general formula (1) below and is liquid at not higher than 50° C. wherein R 1 to R 4 are each independently an alkyl group of 1 to 5 carbons or an alkoxyalkyl group of the formula R′—O—(CH 2 ) n — (R′ being methyl or ethyl, and the letter n being an integer from 1 to 4), and any two from among R 1 , R 2 , R 3 and R 4 may together form a ring, with the proviso that at least one of R 1 to R 4 is an alkoxyalkyl group of the above formula, X is a nitrogen atom or a phosphorus atom, and Y is a monovalent anion; and an ion-conductive polymer having a relative permittivity at 25° C. and 1 MHz of 5 to 50.