Fabrication of supercapacitor using banyan leaves-based activated carbon electrode and formic acid-based polymer electrolyte

Abstract

In the present studies, activated carbon as an electrode material and polyvinyl- alcohol (PVA) as a polymer. Formic acid (FA) and potassium iodide-based electrolyte system have been synthesized for the fabrication of energy storage devices, supercapacitors. The diluted formic acid (CH2O2) in the double-distilled (DD) water has been optimized so that it exhibits maximum conductivity. The electrolyte system has also been prepared with PVA, redox additive (KI) with optimized formic acid (4.0 M). The redox additive concentration has also been identified that can have maximum conductivity. The selected system (PVA + FA + KI) shows the highest conductivity in the range ∼10−1 Scm−1. The banyan leaves (biomass) based carbon electrode (BAC) synthesized as an electrode material. The electric double layer capacitor (EDLC) has been fabricated using BAC as electrodes and (PVA + FA + KI) as electrolyte material. The result of (BAC) based EDLC cell has been compared with the cell fabricated using commercially available activated carbon (AC). The performance of cells has been determined by impedance spectroscopy (IS), Cyclic voltammetry (CV) and charge–discharge (CD) techniques. The overall capacitance of BAC / (PVA + FA + KI) / BAC and AC / FA (4.0 M) / AC have been found to be ∼356 mFcm−2 and ∼100 mFcm−2.