Graphene/SnO2/polypyrrole ternary nanocomposites as supercapacitor electrode materials

Abstract

A ternary electrode material, based on graphene, tin oxide (SnO₂) and polypyrrole (PPy) was obtained via one–pot synthesis. The graphene/SnO₂/PPy (GSP) nanocomposite is composed of a thin conducting film of PPy on the surface of graphene/SnO₂ (GS). An enhanced specific capacitance (616 F g⁻¹) of GSP was obtained at 1 mV s⁻¹ in 1 M H₂SO₄ compared with GS (80.2 F g⁻¹) and PPy (523 F g⁻¹). The GSP electrode shows better cycle stability and no obvious decay after 1000 galvanostatic cycles at 1 A g⁻¹. Its specific power density and energy density can reach 9973.26 W kg⁻¹, and 19.4 W h kg⁻¹, respectively. The excellent electrochemical performance arises from the well-designed structure advantages, the good combination of components and the synergistic effect between the three components. Well-dispersed graphene is used as a framework for sustaining the pseudocapacitive materials of SnO₂ and PPy. The PPy film restricts the aggregation and volume change of SnO₂ during charge–discharge cycling, and also enhances the surface area. The electrochemical results show that the ternary composite of GSP is a promising candidate electrode material for high-performance supercapacitors.