Synthesis of MoS2 incorporated copper cobalt sulphide nanocomposites and investigation of their structural and electrochemical properties

Abstract

In the present investigation, MoS2 incorporated CuCo2S4 nanocomposite has been successfully synthesized by a hydrothermal technique. High resolution transmission electron microscopy imaging demonstrated the successful synthesis of CuCo2S4-MoS2 nanocomposite. The electrochemical capacitor performance of the nanocomposite has been evaluated both in three-electrode and symmetric two-electrode systems. In the three-electrode cell, a specific capacitance of 820 Fg-1 was achieved for CuCo2S4-MoS2 electrode at the current density of 0.5 Ag-1 which is considerably higher than that of CuCo2S4 electrode (249 Fg-1). It was observed that the charge storage capacity, conductivity, and stability of CuCo2S4 had improved significantly due to the incorporation of MoS2. Finally, an asymmetric supercapacitor was fabricated by assembling the CuCo2S4-MoS2 electrode with an activated carbon electrode which demonstrated a large stable working potential window of 1.6 V. A long-term cyclic stability of 89% retention after 1000 galvanostatic charge-discharge cycles were found. As a solid-state device, it delivered a high energy density of 38.22 Whkg-1 at a power density of 400 Wkg-1 and lit up one red LED for 290 s, indicating its superiority over the conventional CuCo2S4 based supercapacitors.