ELECTRODEPOSITION OF POLYPYRROLE/MnO2 NANOCOMPOSITE ON GRAPHITE FELT AS FREE-STANDING ELECTRODE FOR SUPERCAPACITORS

Polypyrrole/manganese dioxide nanocomposite was deposited on graphite felt (GF) via electrodeposition to fabricate polypyrrole/manganese dioxide/graphite felt (PYMG), which can be used as novel free-standing electrode for supercapacitors. The microstructure and morphology of the as-prepared samples were characterized by Fourier transform infrared (FTIR) spectra, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Cyclic voltammogram (CV), chronopotentiometry (CP) and electrochemical impedance spectroscopy (EIS) techniques were employed to investigate the electrochemical performance of the composites. The PYMG electrode displayed specific capacitance as high as 596.3 Fg(-1) at the current density of 0.5 Ag-1, which is much higher than that of polypyrrole/manganese dioxide (PPy/MnO2) composite reported previously. The high specific capacitance of PYMG may be attributed to the fact that the porous GF is a good conductive matrix for the dispersion of PPy/MnO2 composite and it can facilitate easy access of electrolytes to the electrode, which results in enhancement of the electrochemical performance of the composite. Furthermore, the PYMG composite exhibited enhanced specific capacitance compared to MnO2/GF (MGF) and PPy/GF, which may be ascribed to the synergistic effect of PPy and MnO2.