Enhanced electrochemical performance of AgNiSrS/CNT//AC hybrid device for advanced energy storage and hydrogen production

초록

Transition metal sulfides (TMSs) have emerged as attractive materials for electrochemical energy storage and conversion systems due to their high theoretical capacities, rich redox chemistry, and excellent catalytic potential. However, their applied utilization is often limited by poor conductivity and structural degradation during cycling processes. Integrating TMSs with low-dimensional carbon materials, such as carbon nanotubes (CNTs), can significantly improve electron transport, enhance mechanical stability, and increase active site accessibility. In this study, we synthesize and design the novel ternary (silver-nickel-strontium) sulfide integrated with carbon nanotubes. The AgNiSrS/CNTs nanocomposite material was engineered to serve as a multifunctional electrode for hybrid supercapacitor devices and the electrocatalytic hydrogen evolution reaction (HER). The AgNiSrS/ CNT-electrode demonstrated the highest specific capacity (Qs) of 1625.21C/g. The AgNiSrS/CNT//AC hybrid device presented the high Qs of 258.47C/g with excellent rate performance, and long-term cycling stability of 93 % retention over 5000 repeated cycles. A high energy density (Ed) of 55 Wh/kg at a power density (Pd) of 2238 W/kg is obtained. In addition to energy storage capability, the AgNiSrS/CNT electrode displays impressive electrocatalytic behavior for HER in alkaline medium, achieving a Tafel slope of 34 mV/dec and a low over-potential of 77 mV, indicative of accelerated reaction kinetics. These findings emphasize the significant applicability of AgNiSrS/CNT nanocomposites as bifunctional materials for high-performance flexible energy storage systems and sustainable hydrogen generation, paving the way for scalable clean energy applications. The combination of high electrical conductivity, abundant active sites, and structural stability enables this nano-composite to simultaneously deliver superior electrochemical energy storage performance and efficient electrocatalytic activity.

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