A facile hydrothermal synthesis of a reduced graphene oxide modified cobalt disulfide composite electrode for high-performance supercapacitors. Issue 9 (18th January 2016)

• Record Type: Journal Article
• Authors: Liu, Guijing; Wang, Bo; Wang, Lei; Yuan, Yuhe; Wang, Dianlong
• Is Part Of: RSC advances. Volume 6:Issue 9(2016)
• Page Start: 7129
• Page End: 7138
• Publication Date: 2016-01-18
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c5ra25665h
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : In this study, a 3D reduced graphene oxide modified CoS2 composite electrode (CoS2 /RGO) is synthesized by a facile hydrothermal approach. Abstract : In this study, a 3D reduced graphene oxide modified CoS2 composite electrode (CoS2 /RGO) is synthesized by a facile hydrothermal approach. The dimensions of the CoS2 nanoparticles in CoS2 /RGO are effectively reduced due to the geometric confinement of RGO, and a novel, large-scale wave-like structure is formed. This leads to an enlarged specific surface area and improved conductivity and could thus be favourable for both fast electron and ion transport. As a consequence, CoS2 /RGO displays better electrochemical properties than the pure individual components. When the mass ratio of CoCl2 ·6H2 O and GO as the raw materials is 1 : 2, the obtained CoS2 /RGO composite electrode (CoS2 /RGO-2) delivers the highest capacitance of 930.3 F g −1 at 2 A g −1 and retains a capacitance as high as 677.9 F g −1 as the current density increases up to 20 A g −1 . Moreover, in order to obtain high energy and power densities, a high-voltage asymmetric supercapacitor has been designed and constructed using the optimized CoS2 /RGO-2 composite electrode as the positive electrode and activated carbon (AC) as the negative electrode material. Such a device with an operational voltage of 1.6 V can achieve a remarkable energy density of 45.7 W h kg −1 at a power density of 797.0 W kg −1, in addition to the superior rate capability and prominent stability towards long time charge–discharge cycles.