Less Expensive and Eco-Friendly Preparation of Activated Carbon Derived from Coffee Leaf as an Supercapacitors Electrode

Abstract

In this paper, less expensive and eco-friendly biomass-based activated carbon from coffee leaf (CL) was prepared as electrode materials for supercapacitor applications using KOH activation, carbonization, and physical activation in a CO2 atmosphere. Using cyclic voltammetry and galvanostatic charge/discharge techniques, the CL sample was tested in a two-electrode configuration operating in 1 M H2SO4. After physical activation, the percentage reduction of the mass, diameter, thickness, and diameter are 76.47%, 29.38%, 28.57%, and 38.04%, respectively. The CL sample exhibits specific capacitance, energy and power densities of 210 F/g, 29.17 Wh/kg, and 39.99 W/kg at constant current 1 A, respectively. Therefore, the CL sample obtained through KOH activation, carbonization, and physical activation using CO2 atmosphere has a promising future applied as an electrode material for supercapacitor applications.