Abstract: A closed type capacitor (1) includes: an external container (10) which cuts off gas; a pair of polarized electrodes contained in the external container (10); a separator arranged between the electrodes; and a non-aqueous electrolytic liquid containing electrolyte and a non-aqueous organic solvent if necessary. The external container (10) has an opening (10A) for communication between inside and outside the container and a valve mechanism (13) which is arranged to cover the opening (10A) and which is opened and closed by the pressure difference between the inside and outside the container (10). The electrolyte contains more than 30 mass % of ion liquid. This closed type capacitor can minimize separation of electrolyte in the valve path.

Abstract: Secondary cells and electrical double-layer capacitors of excellent charge-discharge efficiency, stability and low-temperature properties can be obtained using nonaqueous electrolytes which contain an ionic liquid that has general formula (1) below and is liquid at not higher than 50° C. and an ion-conductive polymer. In formula (1), R1 to R4 are each independently an alkyl group of 1 to 5 carbons or an alkoxyalkyl group of the formula R?—O—(CH2)n— (R? being methyl or ethyl, and the letter n being an integer from 1 to 4), and any two from among R1, R2, R3 and R4 may together form a ring, with the proviso that at least one of R1 to R4 is an alkoxyalkyl group of the above formula. X is a nitrogen atom or a phosphorus atom, and Y is a monovalent anion.

Abstract: A nonaqueous electrolyte which contains an ionic liquid having general formula (1) below and a melting point not higher than 50° C., a compound which reductively decomposes at a more noble potential than the ionic liquid, and a lithium salt. In formula (1), R1 to R4 are each independently an alkyl group of 1 to 5 carbons or an alkoxyalkyl group of the formula R?—O—(CH2)n— (R? being methyl or ethyl, and the letter n being an integer from 1 to 4), and any two from among R1, R2, R3 and R4 may together form a ring, with the proviso that at least one of R1 to R4 is an alkoxyalkyl group of the above formula. X is a nitrogen atom or a phosphorus atom, and Y is a monovalent anion.

Abstract: Secondary cells and electrical double-layer capacitors of excellent charge-discharge efficiency, stability and low-temperature properties can be obtained using nonaqueous electrolytes which contain an ionic liquid that has general formula (1) below and is liquid at not higher than 50° C. and an ion-conductive polymer. In formula (1), R1 to R4 are each independently an alkyl group of 1 to 5 carbons or an alkoxyalkyl group of the formula R?—O—(CH2)n—(R? being methyl or ethyl, and the letter n being an integer from 1 to 4), and any two from among R1, R2, R3 and R4 may together form a ring, with the proviso that at least one of R1 to R4 is an alkoxyalkyl group of the above formula. X is a nitrogen atom or a phosphorus atom, and Y is a monovalent anion.