Electrochemical investigation of graphene/cerium oxide nanoparticles as an electrode material for supercapacitors

Mechanisms of charge storage, stability, capacitance, morphology and response current of graphene/cerium oxide (CeO2) nanoparticles as an electrode material for electrochemical capacitors have been investigated. Electrochemical properties of the assembled electrodes were studied using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques in 3 M NaCl, NaOH and KOH electrolytes. Scanning electron microscopy (SEM) is used to characterize the microstructure and the nature of prepared electrodes. SEM images confirm the layered structure (12 nm thickness) of the used graphene. The proposed electrode shows a maximum specific capacitance as high as 11.09 F g−1 in the potential range between −0.55 and 0.3 (V vs. SCE) at scan rate of 5 mV s−1. The charge/discharge cycling test shows a good reversibility and confirms that capacitance will increase after 500 cycles by 37%.