Functionalized graphene-polyaniline nanocomposite as electrode material for asymmetric supercapacitors

A polyaniline/sulfonated graphene (PANI/SG) nanostructure was synthesized as electrode material for an asymmetric supercapacitor via a novel in situ chemical oxidative polymerization method including two oxidants. The composite's structure and morphology were characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM) measurements. Furthermore, the electrochemical performances of the composite were characterized by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS) techniques in detail. In addition, we have triumphantly manufactured an asymmetric supercapacitor (ASC) employing activated carbon (AC) and PANI/SG as the positive and negative electrodes, respectively. The ASC possessed an extended potential window (1.4 V), a remarkable cycling property (85.9% capacitance retention after 5000 cycles), and a satisfactory average energy and power density (23 Wh/kg and 6.1 kW/kg).