Enhanced Electrochemical Capacitance of Graphene Nanosheets Coating With Polyaniline for Supercapacitors

A composite of polyaniline (PANI) and graphene nanosheets (GNS) with three-dimensional (3-D) framework structure was prepared via in situ polymerization. The morphology and microstructure of the composite were characterized by scanning electron microscopy, transition electron microscopy and X-ray diffraction. Electrochemical property was examined by cyclic voltammetry and galvanostatic charge-discharge cycles. The microstructure analysis indicates that the PANI homogeneously deposits on the surface of GNS at low content but tend to aggregate between GNS at high content. The electrochemical performance show that the GNS with undestroyed framework are effective to enhance the electrochemical capacitance of the composite. A remarkable specific capacitance of 261.4 F/g (based on GNS/PANI composites with low content of PANI) is obtained at a current density of 100 mA/g compared to 190.6 F/g for pure GNS.