A facile hydrothermal synthesis of a reduced graphene oxide modified cobalt disulfide composite electrode for high-performance supercapacitors

作者：Liu, Guijing; Wang, Bo^*; Wang, Lei; Yuan, Yuhe; Wang, Dianlong^*

来源：RSC Advances, 2016, 6(9): 7129-7138.

DOI：10.1039/c5ra25665h

• LITHIUM-ION BATTERIES
• ASYMMETRIC SUPERCAPACITORS
• CATHODE MATERIALS
• ENERGY DENSITY
• HIGH-POWER
• ELECTROCHEMICAL PERFORMANCE
• LIFEPO4 NANOPLATELETS
• HYBRID ELECTRODES
• NANOSHEET ARRAYS
• ANODE MATERIAL

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 center dot 6H(2)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) 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.

• 出版日期2016
• 单位哈尔滨工业大学