Etlingera elatior leaf agricultural waste as activated carbon monolith for supercapacitor electrodes

Abstract

Recently, biomass waste has become the focus of several researchers because it has promising potential when processed into porous activated carbon. Abundant availability, uncomplicated processing, and more economical are the reasons for choosing biomass as the basic material for making carbon electrodes for electric energy storage supercapacitors. In this study, Etlingera elatior waste biomass is processed into activated carbon by heating at high temperature and impregnation of 0.5 M ZnCl2. The monolith sample was optimized through a single-stage integrated high-temperature pyrolysis process. Where the process of carbonization of N2 gas from a temperature of 30 °C to 600 °C followed by a physical activation process of CO2 gas to a temperature of 800 °C. Determination of the physical properties of the electrodes through density characterization, while the electrochemical properties were analyzed by cyclic voltammetry and galvanostatic charge discharge methods. Cyclic voltammetry and galvanostatic charge discharge analysis were performed with 1 M Na2SO4 aqueous electrolyte at a voltage of 0–1 V and a scan rate of 1 mV/s. Furthermore, the high electrochemical behavior of the CV method was found to be 108 F/g, while for the gcd method, the specific capacitance was much higher at 148 F/g at a constant current density of 1.0 A/g. Further calculations found an energy density of 8.23 Wh/kg and a power density of 161 W/kg. These results support the optimization of 0.5 M ZnCl2 impregnated Etlingera elatior leaves as the base material for activated carbon electrodes to increase the supercapacitor capacitance.