Engineering rGO-CNT wrapped Co3S4 nanocomposites for high-performance asymmetric supercapacitors

In recent years, a tremendous research efforts have been triggered in order to develop efficient electrodes for responding to the increasing demand of high-performance electrodes for various renewable energy storage systems. Herein, we engineer a novel nanocomposites based on the cobalt sulfide (Co3S4) particles warped in carbon nanotubes (CNTs)/reduced graphene oxide (rGO) nanosheets via a low cost, facile, and one-pot hydrothermal method as an efficient electrode for high-performance supercapacitors. By investigating the effect of graphene oxide (GO) concentration and the ratio of GO/CNTs on the electrochemical performance of the electrodes, the rGO(100)-CNT50-Co3S4 electrode was chosen as optimum electrode. This electrode exhibits excellent electrochemical performance with an ultrahigh specific capacitance of 977 F g(-1) at 1 A g(-1) and a remarkable rate capability of 63% after increasing the current density by a factor of 40. Furthermore, the chargestorage mechanism of the electrode was investigated by quantifying its kinetics, which reveals a surface redox behavior for this electrode. The fabricated asymmetric supercapacitor based on the rGO-CNT-Co3S4 and N-doped graphene electrodes as the positive and the negative electrodes exhibits a maximum energy density of 43.5 Wh kg(-1) and a power density up to 6.9 k W kg(-1). The superior electrochemical performance of this electrode was attributed to the synergic effects between the components.