ELECTRIC DOUBLE LAYER CAPACITOR

摘要

PROBLEM TO BE SOLVED: To provide an electric double layer capacitor capable of suppressing deterioration in charging/discharging performance of a capacitor by reducing the reductive decomposition of an electrolytic cation on the surface of a negative electrode while suppressing the oxidative decomposition of an electrolyte on the surface of a positive electrode even if the capacitor is held at the upper limit of a charging voltage at a high temperature for a long time in the case of high-temperature floating test. SOLUTION: In the electric double layer capacitor in which a non-aqueous electrolyte and polarization electrodes are used on both poles and the maximum applied voltage is≥3.0 V, the electrolyte includes a quaternary ammonium salt represented by formula (1) (wherein, R1-R2denote a methyl group or an ethyl group, X-denotes a fluorine-containing anion), and contains no solvent, and the polarization electrode each has the natural potential of≥3.2 V and≤3.6 V for an Li metal electrode (for Li/Li+) in the electrolyte. COPYRIGHT: (C)2010,JPO&INPIT