Abstract: Provided is an electrochemical device which is capable of suppressing problems affecting the capacitor element as a whole, such as a drop in its voltage resistance characteristics and shortening of its life. The capacitor element (10) is constituted of a laminate formed by superposition of a first electrode sheet (11), a separation sheet (14), a second electrode sheet (12), a separation sheet (14), and a third electrode sheet (13) in the named order from the bottom, and folding the laminate along a reference line VSL to double the laminate. In the resulting folded laminate, a collector electrode layer (11a) and polarizable electrode layer (11b) of the first electrode sheet (11), the collector electrode layer (12a) and polarizable electrode layer (12b) of the second electrode sheet (12), the collector electrode (13a) and polarizable electrode layer (13b) of the third electrode sheet (13), and the two separation sheets (14) are connected to each other at the respective folded locations.

Abstract: Provided is an electrochemical device which is capable of suppressing problems affecting the capacitor element as a whole, such as a drop in its voltage resistance characteristics and shortening of its life. The capacitor element (10) is constituted of a laminate formed by superposition of a first electrode sheet (11), a separation sheet (14), a second electrode sheet (12), a separation sheet (14), and a third electrode sheet (13) in the named order from the bottom, and folding the laminate along a reference line VSL to double the laminate. In the resulting folded laminate, a collector electrode layer (11a) and polarizable electrode layer (11b) of the first electrode sheet (11), the collector electrode layer (12a) and polarizable electrode layer (12b) of the second electrode sheet (12), the collector electrode (13a) and polarizable electrode layer (13b) of the third electrode sheet (13), and the two separation sheets (14) are connected to each other at the respective folded locations.

Abstract: This manufacturing method of batteries that comprises the steps of accommodating a battery element 4 in an envelope film body 3 of which one end side is opened to form an opening 3a for injecting an electrolytic solution; and sealing the opening 3a after the electrolytic solution 12 is injected from the opening 3a of the envelope film body 3; wherein an opening 3a side of the envelope film body 3 is made larger than a prescribed shape and dimension to use as a temporary reservoir region 3c of an injected electrolytic solution 12, after injection of a prescribed amount of the electrolytic solution 12 the region 3d of the prescribed shape and dimension being sealed and cut to form a battery. According to the method, a manufacturing method of batteries that can not only make smaller and lighter the batteries but also mass-produce batteries of high quality can be provided.