Highly porous activated carbon prepared from the bio-waste of yellow mustard seed for high-capacity supercapacitor applications

Abstract

Herein, we report the synthesis and electrochemical performance of the porous carbon produced from the bio-waste of the yellow mustard seed plant by the chemical activation process. We have optimized the chemical process to produce mesoporous activated carbon structure with a high specific surface area of 563 m2/g. The N2-sorption analysis confirms the presence of mesoporous structure of the activated carbon. The nanometer scale porosity and chemical composition of the activated carbon was investigated by transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX). The crystallinity and defects analyses were conducted using XRD and Raman spectroscopy, revealing the existence of both amorphous and crystalline phases of the porous activated carbon. The electrochemical double-layered capacitor (EDLC) of the activated carbon electrodes was monitored for long-cycling. The galvanostatic charge-discharge (GCD) studies reveal a significantly high-specific capacity of 198 F/g at a current density of 0.25 A/g. In addition, the cyclic voltammetry (CV) measurements deliver a high reversible capacitive behavior and cyclic stability up to 2100 cycles. Furthermore, we observed a low value of equivalent series resistance (ESR) and charge transfer resistance, indicating an excellent electrode/electrolyte interface which can reversibly facilitate the electrolyte ion transport across the electrodes.