US Patent 7173807 Electric double layer capacitor

To provide an electric double layer capacitor having a low resistance, a high withstanding voltage and an excellent low-temperature characteristic. This object is achieved by employing, for an electric double layer capacitor having a pair of polarized electrodes and an electrolytic solution capable of forming an electric double layer at the interface with the polarized electrodes, an electrolytic solution containing as an electrolyte a salt represented by the formula 1, and as solvents at least (1) a chain carbonate having at most 5 carbon atoms, (2) sulfolane or its derivative and (3) a fluorobenzene: