Synergistic coupling of g-C3N4 and SrV2O6 nanocomposites as advanced electrode materials for aqueous and solid-state supercapacitors

Abstract

In this study, we successfully synthesized pristine SrV₂O₆ and SrV₂O₆/g-C₃N₄ nanocomposites, unveiling their exceptional electrochemical performance with a focus on the impact of g-C₃N₄ content. Both materials exhibited battery-type behavior, but the SrV₂O₆/g-C₃N₄ (1:5) nanocomposite stood out with a remarkable specific capacitance of 512 F/g at 1 A/g and an outstanding cycle retention of 90.86 % after 5000 cycles. This superior performance stems from the synergistic integration of g-C₃N₄ nanosheets with self-assembled micro-nano SrV₂O₆ particles, forming a robust hybrid structure architecture. This optimized structure enhances electrical conductivity, facilitates rapid ion diffusion, and accelerates Faradaic redox kinetics, collectively boosting charge storage efficiency. Furthermore, the fabricated aqueous hybrid supercapacitor (HSC) achieved an impressive energy density of 35.66 Wh/kg at a power density of 750 W/kg, maintaining 90.04 % capacitance retention after 10,000 cycles. Likewise, the solid-state HSC delivered a commendable energy density of 23.20 Wh/kg at a power density of 750 W/kg at the same power density, retaining 84.86 % capacitance after 10,000 cycles. These exceptional electrochemical properties underscore the potential of SrV₂O₆/g-C₃N₄ nanocomposites for next-generation high-performance energy storage systems, making them promising candidates for real-world applications.