Supercapacitor Performance of Activated Carbon from Eucommia Ulmoides Oliver Wood Optimized by the Activation Method

Abstract

Amid the growing demand for sustainable energy storage, biomass-derived porous carbons have emerged as eco-friendly alternatives to conventional electrode materials. This study shows that activated carbon prepared by one-step activation exhibits an enhanced specific surface area and pore volume. The optimum parameter for ameliorating the structural and electrochemical properties is 60 min of microwave heating. The specific surface area, pore volume, and mesopore volume of the resulting activated carbon (EUAC1–60) achieve 1589.0 m²/g, 0.82 cm³/g, and 0.28 cm³/g, respectively. EUAC1–60 exhibits an exceptional defect degree with an I_D/I_G value of 0.92 and can provide ample active sites for ion storage. The electrochemical investigation shows that the EUAC1–60 electrode has the highest specific capacitance of 232.92 F/g at a current density of 0.2 A/g. In addition, continuous cycling performance at a current density of 1 A/g validates its exceptional stability with capacitance retention of 89.90% and Coulombic efficiency of 117.21% after 10,000 cycles. The zinc ion hybrid supercapacitor with the EUAC1–60 cathode and Zn foil anode displayed an excellent energy density performance of 95.58 W h/kg at a power density of 64,800 W/kg. This research presents an innovative approach to the fabrication of high-performance activated carbon electrode materials from Eucommia Ulmoides Oliver, demonstrating its promising potential in supercapacitor applications.