Preparation of a graphene nanosheet/polyaniline composite with high specific capacitance

A graphene nanosheet (GNS)/polyaniline (PANI) composite was synthesized using in situ polymerization. The morphology and microstructure of samples were examined by scanning electron microscopy (SEM), transition electron microscopy (TEM), X-ray diffraction (XRD) and Raman spectroscopy. Electrochemical properties were characterized by cyclic voltammetry (CV) and galvanostatic charge/discharge. GNS as a support material could provide more active sites for nucleation of PANI as well as excellent electron transfer path. The GNS was homogeneously coated on both surfaces with PANI nanoparticles (similar to 2 nm), and a high specific capacitance of 1046 F g(-1) (based on GNS/PANI composite) was obtained at a scan rate of 1 mV s(-1) compared to 115 F g(-1) for pure PANI. In addition, the energy density of GNS/PANI composite could reach 39 W h kg(-1) at a power density of 70 kW kg(-1). (C) 2009 Elsevier Ltd. All rights reserved.