MoS2 mediated tuning of CuCo2S4-MoS2 nanocomposites for high-performance symmetric hybrid supercapacitors

In this investigation, molybdenum disulfide (MoS2) nanosheets, copper cobalt sulfide (CuCo2S4) nanomaterials, and MoS2 incorporated CuCo2S4-MoS2 nanocomposites were synthesized as electrode materials for hybrid supercapacitors. The concentrations of MoS2 were varied and optimized for the synthesis of CuCo2S4-MoS2 nanocomposites to improve their electrochemical properties for use in high-performance energy storage devices. The successful formation of CuCo2S4-MoS2 nanocomposites was confirmed by powder XRD analysis, TEM imaging and X-ray photoelectron spectroscopy analyses. In a three-electrode system, compared to other synthesized electrode materials, the CuCo2S4-MoS2 (80 : 20) nanocomposite with a 20 wt% concentration of MoS2 demonstrated the highest specific capacitance of 1333 F g(-1) at 1 A g(-1) current density and 94% capacitance retention after 5000 charge-discharge cycles. Notably, in a symmetric two-electrode configuration, the optimized CuCo2S4-MoS2 (80 : 20) nanocomposite also exhibited the highest specific capacitance of 670 F g(-1) at 1 A g(-1) current density and achieved an energy density of 33.5 W h kg(-1) at 600 W kg(-1) power density compared to that of other synthesized electrode materials. Finally, a prototype supercapacitor was assembled by utilizing the optimized CuCo2S4-MoS2 (80 : 20) nanocomposite as an electrode material via a coin cell to light up an LED. Our findings demonstrate that incorporation of MoS2 improves electrochemical performance and 20 wt% MoS2 is the optimum concentration to significantly enhance the charge storage capacity, conductivity, and stability of CuCo2S4. The charge storage mechanism of the optimized nanocomposite in a symmetric two-electrode system was comprehensively discussed. The outcome of this investigation demonstrated that the optimized CuCo2S4-MoS2 (80 : 20) nanocomposite with its high charge storage capacity, energy density, and excellent long-term stability can be used as an efficient electrode material for high-performance symmetric hybrid supercapacitors.