PURPOSE: To increase electric capacity by activating a carbon porous material, heat- treating the carbon porous material in vacuum to give active carbon and forming an electrical double layer capacitor comprising a polarizable electrode containing the active carbon and an electrolyte solution in contact with the electrode.
CONSTITUTION: Resin foam comprising a resol type phenolic resin is processed into a given shape and calined at 500-1,200°C in a nonoxidizing atmosphere to give a blocked porous material. Then the blocked porous material is activated in the presence of an oxidizing gas such as steam at 800-1,200°C into ≥0.1g/cm3 bulk density and ≥500m2/g specific surface area, and heat-treated under ≤10-2Torr degree of vacuum in an inert gas flow at 60-250°C to give a blocked active carbon. Then the active carbon trimmed into a given shape to give polarizable electrodes 1. The electrode and a separator 3 are degassed and impregnated with an electrolyte prepared by dissolving an organic electrolyte such as tetraethylammonium tetrafluoroborate in an organic solvent. Then, a pair of polarizable electrodes 1 are arranged while laying the separator 3 between the electrodes and providing a collector 2 such as graphite outside, put in a plastic case and screwed through an insulating packing 4 to give an electrical double layer capacitor.
YOKOYAMA KEIICHI
SHIMOJO MASAYUKI
SHOJI MASANORI
