Synergistic effect of Echinops flower-like Copper sulfide@Cadmium sulfide heterostructure for high-performance all-solid-state asymmetric supercapacitor

The fascinating properties of transition metal chalcogenides, including their distinctive morphologies, large surface areas, crystal structures, tunnel bandgaps, and structural stability, have led to a widespread acceptance of these compounds as ideal electrode materials for energy and environmental applications. Incorporating additional metal chalcogenides into metal chalcogenides to form a heterostructure can further enhance their electrical conductivity and provide them with more active sites. Herein, a simple hydrothermal method is used to synthesize a heterostructure CuS@CdS nanocomposite by integrating Copper sulphide and Cadmium sulphide. Xray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy were used to ascertain the phase formation and structural properties of the synthesized compounds. The electrochemical properties of the obtained materials were investigated. In a three-electrode configuration, a heterostructure CuS@CdS nanocomposite delivers high-specific capacitance (543.6 Fg � 1 at 1 Ag-1) with excellent rate capability and outstanding cycling stability. A heterostructure CuS@CdS nanocomposite and activated carbon were employed as the negative electrode/positive electrode to construct an all-solid-state asymmetric supercapacitor device for real-world applications. This fabricated device exhibits a high energy density of up to 34.9 Wh.kg � 1 and power density of 798.1 W.kg � 1 and outstanding cyclic stability and retains up to 95.5 % over 3000 cycles. The outstanding results demonstrate that the CuS/CdS nanocomposite is an appropriate electrode material for a highperformance supercapacitor.