Abstract: The present invention is an electrochemical double layer capacitor (EDLC) series stack formed into a single electrolyte cell structure. The concatenated multiple electrode assembly stack has electrode assemblies electrically connected in series. The electrode assemblies have a double-sided activated carbon electrode formed on a current collector. Power tabs are connected to the end electrode assemblies. An electrolyte is also provided. A poly bag contains the electrolyte and the electrode assemblies. The electrode assemblies form a double-sided activated-carbon electrode on a current collector. The EDLC stack has a number of segments and mass free zones separating them. The segments are folded so that mass free zones are disposed at the apex of each fold.

Abstract: A case structure generally includes a trough shaped base section, a positive end piece, a negative end piece, and a cover section. The trough shaped base section includes a bottom and two side wall members. The positive and negative end piece are disposed at opposite ends of the base section and include an electrically conductive material at least partially embedded within a thermoplastic material. The cover section is disposed on the base section for sealing the prismatic case. The base section and the cover section can be made from, for example, a polymeric material.