Facile synthesis of cobalt Disulfide/Carbon nanotube composite as High-performance supercapacitors electrode

Abstract Transition metal sulfides are widely used in energy conversion and storage devices due to their distinguished electrochemical activity. In particular, cobalt disulfide (CoS2) shows potential as a good electrode material owing to its low cost and good stability. Here, a series of CoS2/CNT composites with different contents of carbon nanotubes (CNTs) was prepared through a one-step hydrothermal method and used as electrode materials for asymmetric supercapacitors. Their electrochemical performance was also studied. Results show that compared with other composite materials, CoS2/CNT-20 exhibited a larger specific capacitance of 823F g−1 at 0.5 A g−1, satisfactory cycling stability of 93.86% capacitance retention after 7000 cycles at 3 A g−1, and a high energy density of 27.7 Wh kg−1 at the power density of 749.8 W kg−1. These findings imply their promising application in energy storage devices.