α-Manganese Dioxide (α-MnO2) Coated with Polyaniline (PANI) and Reduced Graphene Oxide (rGO)-Based Nanocomposite for Supercapacitor Application

This work reports the preparation and testing of a composite material composed of alpha-Manganese dioxide (alpha-MnO2) coated with polyaniline (PANI) and reduced graphene oxide (rGO) for supercapacitor application. The structure and morphology of the materials were characterized by using X-ray diffraction (XRD) analysis, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), thermogravimetric analysis (TGA) and Raman spectroscopy. The electrochemical performances of the materials were investigated by using cyclic voltammetry (CV), Galvanostatic charge-discharge (GCD), cyclic stability and electrochemical impedance spectroscopy (EIS). The alpha-MnO2-coated PANI/rGO nanocomposite exhibited a specific capacitance of 261 F g(-1) at the scan rate of 5 mV s(-1) with 75% capacitance retention after 2000 cycles at 5 A g(-1). It showed a specific energy of 11 W h kg(-1) and specific power of 1250 W kg(-1).