Patent ID: 8248756

Claim:
An electrochemical device comprising: four or more electrodes which are laminated with separators provided between the respective electrodes; an electrolyte filled between the respective electrodes; and a sealing member which covers the periphery, wherein the electrodes are arranged so that the polarities alternately change in the lamination direction, and each of the electrodes has projections projecting from diagonally opposite positions on the peripheral edge so that the positions of the projections of the electrodes of different polarities are opposite to each other in the lateral direction and the projections of the electrodes of the same polarity are aligned and welded to each other, thereby constituting four welded projections of the electrodes to support by the electrodes of one of the polarities diagonally in a first direction the electrode of the other polarity and the separators attached thereto interposed between the electrodes of the one of the polarities, and to support by the electrodes of the other polarity diagonally in a second direction crossing the first direction the electrode of the one of the polarities and the separators attached thereto interposed between the electrodes of the other polarity, each of the separators has projections which are positioned between the projections of the adjacent electrodes of different polarities, and the longitudinal length of each of the electrodes and separators including the respective projections is the same.