RGO-wrapped MnO2 composite electrode for supercapacitor application

In this paper, we report on a facile electrodeposition method to produce reduced graphene oxide (RGO)–manganese oxide (MnO2) composite electrode for supercapacitor application. The nature of the composite electrode was examined by X-ray diffraction (XRD). The morphology and composition of the composite electrode were studied using field emission scanning electron microscope (FESEM) and energy dispersive X-ray spectroscopy (EDX). FESEM revealed the wrapping of MnO2 nanoparticles by RGO sheets. Supercapacitor cell behavior was examined using cyclic voltammetry (CV), galvanostatic charge–discharge (CD) and electrochemical impedance. The optimum specific capacitance obtained was 378 F/g at scan rate of 1 mV/s for 13 min of electrodeposition. This is attributed to the high surface area contributed by MnO2 nanoparticles and conductive pathway provided by RGO sheets. Cycling studies showed that this cell can retain 83% of original specific capacitance after 1000 cycles. This high capacitance composite electrode has long cycle stability which makes it suitable for supercapacitor application.