Accelerated publicationFabrication of a supercapacitor with a PVA–KOH–KI electrolyte and nanosilver flexible electrodes

A supercapacitor was assembled by sandwiching a gel electrolyte containing alkaline polyvinyl alcohol and potassium hydroxide (PVA–KOH) in the presence and absence of potassium iodide (KI) between two nanosilver flexible electrodes (NSFEs) made by inkjet printing of reactive inks on paper as a substrate. The electrochemical properties of this supercapacitor were investigated by cyclic voltammetry and charge–discharge galvanostate techniques. Various salts were used in the PVA–KOH system, but KI was finally selected as the best salt with an optimum concentration of 0.072 M. The cyclic voltammograms of NSFEs in contact with PVA–KOH–KI as a gel electrolyte at different scan rates suggested that the reaction is diffusion-limited. The specific capacitance of the nanosilver electrodes or the supercapacitor was calculated as 0.22 F g− 1 by the galvanostate charge–discharge (GCD) techniques.