Synthesis and characterizations of electroless oil palm shell based-activated carbon/nickel oxide nanocomposite electrodes for supercapacitor applications

Abstract

Activated carbon (AC) prepared by two-stage microwave-induced physical activation of oil palm shell have been coated using electroless plating technique to form nanocomposite material. The composite materials were calcinated at different temperature of 300, 400 and 500 °C for one hour. The nanocomposite materials were evaluated as potential electrodes for supercapacitors. Using the composite electrodes in a two-electrode symmetrical capacitor, the properties of the composite electrodes were investigated by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS). Results from electrochemical measurements show that the nanocomposite electrodes exhibit superior capacitive performance compared with the AC electrode. The specific capacitance have been found to increase by 85–205% with respect to the AC electrode. In addition, the specific capacitance as well as the energy density were found to reduce with the increment of the calcination temperature. The composite electrode calcinated at 300 °C offers the maximum enhancement of 205% in both specific capacitance and energy density.