Performance of onion root based activated carbon electrodes at various physical activation temperatures for supercapacitor applications

Abstract

Biomass based activated carbon holds great potential as a supercapacitor electrode due to its abundant availability, low cost, and environmentally friendly properties. This study aims to analyze the electrochemical characteristics and performance of activated carbon derived from shallot roots, synthesized through chemical activation using H₃PO₄ followed by physical activation. Scanning Electron Microscopy analysis results reveal the development of the structure and composition of the resulting material. Electrochemical testing using cyclic voltammetry and galvanostatic charge-discharge indicates that increasing the physical activation temperature enhances pore formation and improves material performance. The activated carbon sample exhibited the best performance with a specific capacitance of 126 F/g indicating good potential as a supercapacitor electrode.