Fabrication 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 (RI) 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 RI 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. (C) 2015 Elsevier B.V. All rights reserved.