Study of electrode processing and cell assembly for the optimized performance of supercapacitor in pouch cell configuration

Laboratory testing of supercapacitor cells are generally performed in Swagelok or coin cell setup, where two small electrodes and electrolyte-saturated separators are placed in tightly packed cell assembly. However, more often the performances achieved in laboratory testing are failed to replicate in larger commercially viable cells due to different factors unrelated to material properties but linked to the different electrode and cell fabrication parameters such as current collector surface, electrode formulation, density and mass loading, calendering condition etc., all of which significantly affect the overall performance in terms of capacitance, durability, energy and power density. Therefore, an intermediate prototyping step, where the electrode processing and cell fabrication are performed in close-to-real industrial format, can enable a realistic and consistent evaluation of supercapacitor cell. This report summarizes different problems faced during a prototyping effort of supercapacitor from 1.12 cm(2) Swagelok cell to a 20.25 cm(2) pouch cell prototype using state of the art electrodes in standard organic electrolyte. Various electrode processing and cell assembly parameters were evaluated and compared with an industrially manufactured electrode. Based on the meticulously optimized parameters, an assembled multilayer pouch cell with 25 F capacitance outperforms a commercially available cylindrical cell in terms of specific energy.