Two – step approach of fabrication of three – dimensional reduced graphene oxide – carbon nanotubes – nickel foams hybrid as a binder – free supercapacitor electrode

Abstract

A facile method is designed to prepare 3D reduced graphene oxide (rGO) - carbon nanotubes (CNTs) - nickel foams (NF). In this research, the 3D rGO-CNTs-NF electrode is fabricated by combination of electrophoretic deposition and floating catalyst chemical vapor deposition. The vertically-aligned CNTs forests not only effectively prevent stacking of rGO sheets but also facilitate the electron transfer during the charge/discharge process and contribute to the whole capacitance. Moreover, the 3D rGO-CNTs-NF hybrid can be used directly as electrodes of supercapacitor without binder. Additionally, the hybrid shows a specific capacitance of 236.18 F g⁻¹ which is much higher than that of the rGO - NF electrode (100.23 F g⁻¹). Importantly, the energy density and power density of 3D rGO-CNTs-NF are respectively as high as 19.24 Wh kg⁻¹ and 5398 W kg⁻¹, indicating that our work provides a way to design hierarchical rGO-based architecture composed of rGO, CNTs and various electroactive materials for high-performance energy storage devices.