Exploring the redox characteristics of vanadium copper sulfide (VCuS) and its applications as a high-performance electrode for energy storage devices

The increasing energy consumption in modern society requires long-term energy storage technology. The main problem for a sustainable energy storage system is energy optimization and power density. The vanadium copper sulfide (VCuS) was hydrothermally synthesized in this study. The electrochemical activity of the VCuS was studied with the three-cell configuration, which demonstrated a maximum capacity of 475C/g (at 1.0 A/g), higher than VS2 and CuS. The surface area for VCuS was 13.65 m2/g, estimated using the BET measurement. The conductivity of VCuS was measured to be 233 mS/cm, while 1 M KOH electrolyte shows maximum conductivity of 206 mS/cm. The supercapattery (VCuS//AC) delivers an excellent specific capacity of 163C/g having a current density of 1.0 A/g. The VCuS//AC can provide energy of 34.5 Wh/kg at 800 W/kg power density (at 1.0 A/g). Additionally, the VCuS//AC durability test measured capacity retention after subjecting it to 10,000 cycles. The VCuS//AC displayed excellent cycling stability of 80 after 10,000 cycle repetitions. © 2023 Elsevier Ltd