US Patent 7248460 Electric double layer capacitor and electrolytic cell

An electric double layer capacitor includes: a cell which includes a pair of polarizable electrodes impregnated with an electrolytic solution and disposed in opposed relation with a separator interposed therebetween; collector electrodes respectively attached to the polarizable electrodes; and a sealing member of a synthetic resin which seals a periphery of the cell. The collector electrodes extend outward of the sealing member through the sealing member in contact with the sealing member. The collector electrodes each have a rough surface portion which extends through the sealing member.