Supercapacitors from Free-Standing Polypyrrole/Graphene Nanocomposites

Interfacial/in situ oxidative polymerization of polypyrrole in the presence of functionalized graphene sheets produces high-quality composites for supercapacitors, as analyzed by electrochemical impedance spectroscopy and cyclic voltammetry analysis. The synergistic interaction induced by the growth of p-type polypyrrole on the surface of negatively charged carboxylate functionalized graphene sheets results in higher storage capacity than graphene-only or polymer-only films. The high conductivity of p-doped polypyrrole and high surface area of graphene promote high charge accumulation in capacitors. We report the optimization of the relative concentrations of carboxylate functionalized graphene in the polypyrrole matrix to maximize the composition’s capacitance to 277.8 F/g.