High Performance Supercapacitor Based on Activated Carbon Electrodes Prepared Using Microwave Temperature as Process Parameter

Abstract

The activated carbon (AC) electrodes were prepared by a two-step microwave-induced CO2 activation of OPS using bed temperature as control parameter. The electrochemical properties of the AC electrodes were investigated at room temperature by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS) in 1 M H2SO4. The morphology, textural and chemical composition of the AC electrodes were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption isotherm and X-ray diffraction (XRD). The specific surface area (SBET), the total pore volume (Vt) and the micropore volume (Vμ) were found to increase with increase in both bed temperature and activation time with AC900-40 having the highest BET surface area of 574.37 m g, total pore volume of 0.124 cm g and micropore volume of 0.116 cm g. However, activation time was observed to have more profound effect as indicated by the values for AC800-40 being higher than that of AC900-20. The results of the electrochemical characterization show that the AC electrodes exhibit specific capacitance, power density and energy density of 134.68 F g, 225 W kg and 4.68 Wh Kg, respectively. Thus, the results indicated that using bed temperature as control parameter in microwave heating is a promising route to producing AC electrode with excellent performance.