Scalable fabrication of a flexible interdigital micro-supercapacitor device by in-situ polymerization of pyrrole into hybrid PVA-TEOS membrane

Abstract

This paper addresses the development of an electrically conductive flexible nanocomposite membrane by the incorporation of an optimum amount of pyrrole into tetraethyl orthosilicate crosslinked poly(vinyl alcohol). The incorporated pyrrole underwent in-situ chemical oxidation in presence of iron(III) chloride. The resulting membrane was subjected to various techniques to understand its physico-chemical properties. The nanocomposite membrane demonstrated an excellent electrical conductivity of 4.56 S cm−1 with a desired flexibility. The electrochemical properties of the electrode membrane were systematically investigated using cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy. The resulting electrode membrane exhibited a specific capacitance as high as 484 F g-1 at a current density of 0.1 A g−1 with an excellent cycle life stability. Based on its excellent electrochemical performance, we have developed both interdigital micro-supercapacitor and sandwich-type supercapacitor devices; among these, the interdigital micro-supercapacitor exhibited a specific capacitance of 51.42 F g-1 at 0.05 A g−1, which is two times higher than that of sandwich-type supercapacitor (25.49 F g−1). Furthermore, the method adopted here for the fabrication of an interdigital micro-supercapacitor device can be easily applied to large-scale fabrication of electrically conductive membranes and opens up new opportunities for flexible lightweight energy storage devices.