Synthesis and Electrochemical Characterization of Activated Porous Carbon Derived from Walnut Shells as an Electrode Material for Symmetric Supercapacitor Application †

Abstract

One of the greatest options to address the growing need for hybrid energy storage systems is a supercapacitor with high specific capacitance, high power density, and more charge and discharge cycles. The valorization of walnut shells, a bio waste, into an activated biocarbon electrode material for the symmetric electric double-layer supercapacitor (EDLC), has been carried out. The valorization method comprises of two-steps for the synthesis of activated biocarbon which are thermal carbonization and ZnCl2 chemical activation of walnut shells at 700 °C. The sample has good long-term stability and a specific capacitance of 50 Fg−1 @1 Ag−1, making it an excellent supercapacitor electrode material. So, the symmetric electric double-layer capacitor’s (EDLC) promising electrode material was found to be porous AC samples made from walnut shells.