Methods for manufacturing an electric double layer capacitor and an electrolyte battery, electric double layer capacitor and electrolyte battery

An electric double layer capacitor is provided with a cell (2), in which a pair of polarizable electrodes (20,21), which are impregnated with an elecrolyte, are disposed in opposition on either side of a separator (6); wherein the polarizable electrodes (20,21) are provided with collector electrodes (3,30) a peripheral portion of the cell (2) is sealed by a sealing member (4) composed of synthetic resin, and the sealing member (4) is formed by abutting two case halves (40,41). A manufacturing method for the capacitor includes a process step of providing at least one long slit (31) in the collector electrodes (3,30); a step of forming the case halves (40,41) formed by insert molding on the collector electrodes (3,30) and filling the slit, the case halves (40,41) comprising a recess (42), one side of which extends in the lengthwise direction of the slit (31) and, the cell (2) being fitted into a portion inward from the slit (31); and a step of joining the case halves (40,41) by abutting the case halves (40,41) and applying ultrasonic vibration either in a perpendicular direction or a diagonal direction with respect to the lengthwise direction of the slit (31).