Development and performance evaluation of reduced graphene oxide based all-flexible supercapacitors with open and short circuit tests

Flexible and wearable charge storage devices are the dire need of modern technology. This work is focused on an all-flexible strategy, both in terms of electrolyte selection and electrode fabrication in order to develop a supercapacitor. For electrode fabrication, sodium silicate is used as a flexible binder which provides flexibility to the electrode material without compromising its conductivity. A chemical binder provides multifold advantage of flexibility of the electrode as well as the capacitive nature of the material. Thus, the binder acts as a dynamic variant, attracting the collected charge carriers to itself rather than recombining them at the separator layer, improving the supercapacitor's self-discharge ability. To transport ions, Polyvinyl Alcohol is chosen as a separator, whereas KOH and H 3 PO 4 are chosen as electrolytes. To improve the electrode flexibility, four different electrode materials are mixed with sodium silicate solution, including single and double mass activated carbon and reduced Graphene Oxide (rGO). At pre-fabrication stage, the integral components i.e., electrodes, electrolytes and binders are individually characterized by multiple evaluation techniques. Furthermore, the effect of rGO on the performance of supercapacitors is studied in detail. The next-generation Randless model is evaluated for better charge collection and prevention of charge recombination in the supercapacitors. Herein, the open and short-circuit states of the fabricated supercapacitors are evaluated where all the supercapacitors are charged for about 3 min and are fully discharged in more than 30 min. The addition of rGO in double mass activated carbon is also found to reduce the overall charge collection.