Bridging Material Testing and Device Fabrication: AgVO ₃ as an Efficient Energy Storage Electrode

Supercapacitors have emerged as essential energy storage devices due to their high-power density, rapid charge–discharge capability, and long cycle life, making them ideal for applications requiring fast and reliable energy delivery. In this work, silver vanadate (AgVO3) was synthesized via a simple, cost-effective coprecipitation method and was investigated through XRD, SEM, XRF, Raman, UV–Vis, BET, and XPS, confirming its crystalline phase, optical band gap, surface composition, and morphology. The electrochemical performance was evaluated in 1 M KOH and 1 M NaOH electrolytes, with KOH demonstrating superior capacitive behavior due to enhanced ionic conductivity and redox activity. A symmetric AgVO3//AgVO3 device was further assembled, exhibiting high capacitance, good rate capability, and stable cycling performance. Significantly, the device successfully powered a light-emitting diode (LED), highlighting its practical potential for real-world energy storage applications. These results establish AgVO3 as a promising electrode material for next-generation supercapacitors.