| abstract |
An electrical capacitor includes an organic electrolyte to provide high power, high energy density, and broad operating temperature range. The capacitor includes electrodes and an electrolyte system comprising a salt combined with a solvent containing a nitrile. The electrolyte system is selected to be relatively nonreactive and difficult to oxidize or reduce so as to produce a high electric potential range. As examples, the electrolyte may include a solvent selected from the group consisting of acetonitrile, succinonitrile, glutaronitrile, propylene carbonate, and ethylene carbonate; a salt cation selected from the group consisting of tetraalkylamonium (R 4 N + ) and alkali metals; and an anion selected from the group consisting of trifluoromethylsulfonate (CF 3 SO 3 - ), bistrifluoromethylsulfurylimide (N(CF 3 SO 2 ) 2 - ), tristrifluoromethylsulfurylcarbanion (C(CF 3 SO 2 ) 3 - ), tetrafluoroborate (BF 4 - ), hexafluorophosphate (PF 6 - ), hexafluoroarsenate (AsF 6 - ), and perchlorate (ClO 4 - ). |