Synthesis of Carbon Nanotube/Graphene Composites by One-Step Chemical Vapor Deposition for Electrodes of Electrochemical Capacitors

Chuen-Chang Lin,Yi-Wei Lin

doi:10.1155/2015/741928

Abstract

To control the packing density of carbon nanotubes (CNTs) and the number of graphene layers, carbon nanotube/graphene composites are directly grown on cobalt (Co) catalysts-coated nickel foam by one-step ambient pressure chemical vapor deposition (CVD) at different temperatures and times. The carbon nanotube/graphene composites grown by one-step CVD at 850°C for 10 min possess the highest specific capacitance. Furthermore, a lower growing temperature leads to a higher packing density of CNTs and a smaller number of layers of graphene. A shorter growing time also leads to a smaller number of layers of graphene.

Highlights

Electrochemical capacitors are charge-storage devices which possess a higher power density and a longer cycle life than batteries [1, 2]
(c) Figure 4: The FESEM images of carbon nanotube/graphene composites grown by one-step chemical vapor deposition (CVD) for 10 min at different growing temperatures ((a) 850∘C, (b) 900∘C, and (c) 950∘C)
The cyclic voltammetry (CV) curve at a potential scan rate of 100 mV/s in a 6 M KOH solution for carbon nanotube/graphene composites grown by one-step CVD for 10 min at 850∘C is shown in Figure 1, which exhibits a nearly rectangular shape

Summary

Introduction

Electrochemical capacitors are charge-storage devices which possess a higher power density and a longer cycle life than batteries [1, 2]. Graphene has higher accessibly specific surface area compared with CNTs as well as activated carbon and higher conductivity compared with activated carbon as well as CNTs [14,15,16]. These properties make them potentially suitable for fabrication of electrodes in electrochemical capacitors

Methods

Results

Conclusion