Tailoring the Electrochemical Interplay of Tri-Metallic Co–Ni–Zn Telluride Frameworks for a High-Performance Supercabattery

The integration of multiple transition metals within a telluride matrix induces a synergistic charge storage mechanism, enabling enhanced Faradaic kinetics and accelerated ion diffusion pathways owing to abundant multielectron redox activity and high intrinsic electrical conductivity. In this study, a cobalt–nickel-zinc-based trimetallic telluride (CoNiZnTe) was synthesized via a cost-effective coprecipitation route followed by thermal tellurization. A series of bimetallic tellurides with different metal combinations was prepared and systematically evaluated, and the trimetallic composition in telluride was optimized to achieve superior electrochemical performance. The optimized CoNiZnTe electrode delivered a high specific capacitance of 1420 F g^–1 at a current density of 1 A g^–1, along with excellent cycling stability, maintaining 91.1% of its initial capacitance over 12,000 charge–discharge cycles in a three-electrode configuration. Moreover, Dunn’s analysis for CoNiZnTe revealed that diffusion-controlled processes accounted for 73% of the total charge-storage contribution at a scan rate of 1 mV s^–1, indicating a strong diffusion-governed electrochemical behavior. Further, an all-solid-state supercabattery device was fabricated using CoNiZnTe as the anode, activated carbon as the cathode, and a PVA-KOH gel electrolyte. The device achieved an impressive energy density of 128.8 Wh kg^–1 at a power density of 794.4 W kg^–1 and retained 92.5% of its capacitance after 12,000 cycles. Notably, the device sustained a high energy density of 109.8 Wh kg^–1 even at a power density of 4000 W kg^–1. Thus, these findings underscore the potential of trimetallic telluride nanostructures as high-performance electrode materials and pave the way for the development of next-generation electrochemical energy storage technologies.