Supercapacitors based on low-temperature partially exfoliated and reduced graphite oxide

• Published in: Journal of power sources 2012-08, Vol.212, p.105-110
• Main Authors: Ye, Jian, Zhang, Haiyan, Chen, Yiming, Cheng, Zhengdong, Hu, Li, Ran, Qiyan
• Format: Article
• Language: English
• Subjects: Ambient pressure; Applied sciences; Capacitors. Resistors. Filters; Electrical engineering. Electrical power engineering; Electrochemical properties; Exact sciences and technology; Functionalized graphene; Low temperature; Partially reduced; Supercapacitors; Various equipment and components
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2012.03.101

Thermally exfoliated graphite oxide (GO) has been prepared at a low temperature and ambient pressure usually contains flourish oxygen functional groups. We find that complete oxidized graphite can be successfully expanded, as well as partially exfoliated and reduced at a very low temperature about 200 °C and ambient pressure without any supplementary conditions such as high vacuum or under hydrogen environment. The electrochemical properties of supercapacitor electrodes are studied by cyclic voltammetry (CV) and galvanostatic charge/discharge (DC) methods. Supercapacitors are constructed with as-prepared functionalized graphene have good electrochemical performance, with a maximum specific capacitance of 315 F g−1 at the charge/discharge current density of 100 mA g−1 using 1 M KOH electrolyte and a high charge/discharge efficiency of about 97%. ► We report graphite oxide (GO) expansion at 200 °C and ambient pressure. ► The as-prepared graphene contains flourish oxygen functional groups. ► The maximum specific capacitance was 315 F g−1, higher than prepared at vacuum. ► The charge/discharge efficiency was about 97% at a current density of 100 mA g−1. ► This simple method shows great potential application of graphene supercapacitors.