Vertically oriented few-layer graphene-nanocup hybrid structured electrodes for high-performance supercapacitors

Abstract

A high-performance supercapacitor was successfully developed using graphene-based 3D hybrid nanostructured electrodes. The 3D hybrid nanostructure, consisting of vertically oriented few-layer graphene (VFG) grown on an alveolate Pt film with high-density nanocups, was synthesized by a simple and efficient “one-step” method. The 3D VFG-nanocup hybrid structured electrodes showed a high specific surface area for ion transmission and storage, which contributes to the enhancement of areal capacitance by accommodating more charges in a given footprint area than that of conventional plane-structured electrodes. Electrochemistry results indicate that the 3D VFG-nanocup hybrid structured electrodes exhibit a high specific capacitance up to 1052 μF cm⁻² (three times that of the VFG-plane, at approximately 337 μF cm⁻²), and a good cycling stability with about 93% capacitance retention after 3000 cycles. These easily fabricated, high-performance 3D hybrid nanostructured electrodes offer great promise in energy storage device applications.