Electrochemical characterization of in situ polypyrrole coated graphene nanocomposites

Graphene/polypyrrole nanocomposites were prepared by in situ oxidative polymerization method by varying the weight percentage of graphene. FTIR study confirmed the formation of polypyrrole in presence of graphene. Field Emission Scanning Electron Microscopy (FESEM) and High Resolution Transmission Electron Microscopy (HRTEM) were used to characterize the morphology of the nanocomposites which showed a uniform coating of graphene with the polypyrrole. From the cyclic voltammetry (CV) measurement it was found that the capacitances of the nanocomposites were increased up to a certain percentage of graphene and after which it showed a downward trend. The maximum capacitance value and energy density, among the composites studied, were found to be 409 F/g and 227.2 Wh/Kg at 10 mV/s scan rate. However, maximum power density achieved was 4617 W/kg at a scan rate of 200 mV/s.

► In this study we have prepared the in situ graphene/polypyrrole nanocomposite with varying percentage of graphene.
► The morphological, electrochemical and thermal analyses of the different nanocomposites are carried out.
► The specific capacitance, energy density and power density of the nanocomposites are found to be increasing with the increase in graphene percentage up to certain extent and then decreases.