Characterization of MgCo2O4 as an electrode for high performance supercapacitors

Metal cobaltites have promising electrochemical properties for their application as an energy storage medium. In this paper, usefulness of MgCo2O4 as a supercapacitor electrode is demonstrated and compared its performance with two other cobaltites, MnCo2O4 and CuCo2O4. The materials are synthesized using molten salt method and characterized by X-ray diffraction, scanning electron microscopy, BET surface area, cyclic voltammetry, galvanostatic charge-discharge cycling, and electrochemical impedance spectroscopy techniques. The MgCo2O4 electrodes show superior charge storage properties in 3 M LiOH among a diverse choice of electrolytes. The MgCo2O4 show higher theoretical (similar to 3122 F/g) and practically achieved capacitance (similar to 320 F/g), larger coulombic efficiency, and cycling stability than the other two; therefore, it could be developed as a low-cost energy storage medium. (C) 2015 Elsevier Ltd. All rights reserved.