Reduced Graphene Oxide/Carbon Nanotube Composites as Electrochemical Energy Storage Electrode Applications

Wenyao Yang,Tianjun Peng,Bangchao Yang,Ke Tang,Jianhua Xu,Jingfeng Wang,Yan Chen

doi:10.1186/s11671-018-2582-6

Abstract

We demonstrate an electrochemical reduction method to reduce graphene oxide (GO) to electrochemically reduced graphene oxide (ERGO) with the assistance of carbon nanotubes (CNTs). The faster and more efficient reduction of GO can be achieved after proper addition of CNTs into GO during the reduction process. This nanotube/nanosheet composite was deposited on electrode as active material for electrochemical energy storage applications. It has been found that the specific capacitance of the composite film was strongly affected by the mass ratio of GO/CNTs and the scanning ratio of cyclic voltammetry. The obtained ERGO/CNT composite electrode exhibited a 279.4 F/g-specific capacitance and showed good cycle rate performance with the evidence that the specific capacitance maintained above 90% after 6000 cycles. The synergistic effect between ERGO and CNTs as well as crossing over of CNTs into ERGO is attributed to the high electrochemical performance of composite electrode.

Highlights

In the last decades, supercapacitors have been widely studied in order to meet the rapidly growing demands of new energy-device with high-power, high energy, high charge/discharge rates and long cyclic life [1]
The obtained graphene oxide (GO)/carbon nanotubes (CNTs) films were put into an electrolytic tank, the GO was electrochemically reduced into electrochemically reduced graphene oxide (ERGO), and an ERGO/CNT composite film was obtained
The CNTs have embedded in ERGO evenly after the physical mixing and electrochemical reduction

Summary

Introduction

Supercapacitors have been widely studied in order to meet the rapidly growing demands of new energy-device with high-power, high energy, high charge/discharge rates and long cyclic life [1]. Activated carbon, carbon nanotubes, mesoporous carbon, nano-carbon have been investigated for use as electrodes in electrochemical double-layer supercapacitors. The pseudo-supercapacitors materials, conductive polymers and transition metal oxides, storing energy through a faradic process have been widely explored [2, 3]. Graphene and its composites have attracted a wide range of research for the electrode material because of their large surface area, high carrier mobility, and excellent electrochemical stability [4,5,6]. As a one-atom thick layer of carbon atoms arranged in a honey-comb lattice, graphene is well-known for its high specific capacitance as energy storage applications [7, 8]. Large area preparation of high quality graphene films as energy storage applications are still in challenges [9, 10]

Methods

Results

Conclusion