The Electrochemical Performance of Simple, Flexible and Highly Thermally Stable PVA-TiO2 Nanocomposite in an All-Solid-State Supercapacitor

Abstract

The construction and constitution of an all-solid-state supercapacitor (SC) energy storage device is heavily reliant on key elements and factors, namely, the electrochemical, thermal and mechanical stability of distinctive materials, the method of electrode and electrolyte preparation, formation of cells and packaging, to highlight a few. In our report, the preparation of an all solid state supercapacitor based primarily on the flexible PVA/TiO2 nanocomposite polymer electrolyte membrane (NCPEM) that served as an electrolyte cum separator and the multi-walled carbon nanotube (MWCNT) used as electrodes, are detailed. Among the varied combinations of TiO2 nanofillers with PVA polymers, the combination of 3wt% TiO2 produced the best energy storage performance in two electrode configuration. PVA/3wt%TiO2 blend membranes provided excellent thermal stability (up to 280 °C), mechanical stability (up to 50.21 MPa) and an incredible electrochemical performance. Due to the superior ionic transport facilitated by the electrode-electrolyte interface, the SC attained a specific capacitance of 137.72 F/g and an energy density of 19.12 Wh/Kg. It also acquired a power density of 277.7 mW/Kg at a current density of 1 A/g and exceptional capacitance retention of 94.08% over 6000 cycles. In order to substantiate this concept, tests to probe the comparison in electrochemical performances between PVA/3wt%TiO2 membrane and the commercially available Nafion 112 membrane along with same MWCNT electrodes, were conducted.