Facile synthesis of shape-controlled graphene–polyaniline composites for high performance supercapacitor electrode materials

Abstract

Graphene–polyaniline (PANI) nanocomposites with different morphologies were successfully fabricated by an effective one-step hydrothermal method. The morphologies of PANI could be controlled from nanowires to nanocones by adjusting the amount of aniline with the assistance of an ultrasonication process. By taking the advantages of the high conductivity of graphene and the pseudocapacitance of PANI, graphene–PANI composites were used as an example for the application to the supercapacitor electrode materials. The cyclic voltammograms (CV) and galvanostatic charge–discharge measurements demonstrate that the graphene–PANI shows excellent electrochemical properties. The graphene–PANI nanowire composite (724.6 F g⁻¹) exhibited higher specific capacitance than that of the graphene–PANI nanocone composite (602.5 F g⁻¹) at a current density of 1.0 A g⁻¹. Furthermore, the graphene–PANI nanowire composite exhibited outstanding capacitive performance with a high specific capacitance of 957.1 F g⁻¹ at 2 mV s⁻¹ and a high cycle reversibility of 90% after charge–discharge 1000 cycles. The improved electrochemical properties of the graphene–PANI nanocomposites suggest their promising applications to high-performance supercapacitors.