Co3O4@MnO2 core shell arrays on nickel foam with excellent electrochemical performance for aqueous asymmetric supercapacitor

At present, a lot of attention has been paid to the reasonable design and synthesis of materials with core shell structure for high-performance supercapacitors. Herein, the Co3O4@MnO2 core shell arrays on nickel foam are successfully synthesized via a facile and effective hydrothermal method followed with annealing process. The sample was characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Electrochemical performance of the Co3O4@MnO2 material was studied using cyclic voltammetry, charge/discharge cycling, and electrochemical impedance measurements in 6 mol L-1 KOH aqueous electrolyte. The results indicated that the Co3O4@MnO2 material presented excellent electrochemical performance in terms of specific capacitance, cyclic stability, and charge/discharge stability.