Synthesis of MnCo2O4.5/graphene composite as electrode material for supercapacitors

Abstract

MnCo2O4.5/graphene composite is obtained by a simple hydrothermal method. The as-synthesized MnCo2O4.5/graphene composite is characterized by X-ray diffraction, and scanning electron microscopy. Electrochemical property of MnCo2O4.5/graphene composite is carried out by cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy. MnCo2O4.5/graphene composite exhibits good supercapacitive performance. The specific capacitances of MnCo2O4.5/graphene composite at 5 mV s-1 and at 0.5 A g-1 are 255.8 and 252.3 F g-1, respectively. 88.7% of the specific capacitance is retained for a 16-time current density increase, indicating its superior rate capability. At the 1000th cycle, MnCo2O4.5/graphene composite shows a specific capacitance of 225.6 F g-1 at 1.0 A g-1, which is 92.6% of initial specific capacitance, demonstrating its excellent cycling stability. These characteristics illustrate that MnCo2O4.5/graphene composite is a promising electrode material in supercapacitors.