Hierarchically Structured 3D Nanoporous Vanadium Oxide Transparent Electrodes for Next-Generation Supercapacitors

This article describes the automatic spray pyrolysis deposition (ASPD) process for the synthesis of hierarchically structured 3D nanoporous vanadium oxide (V2O5) transparent material on a fluorine-doped tin oxide (FTO) substrate. The deposition of material occurs at 673 K using an aqueous solution of NH4VO3, with a constant solution spray rate of 10 mL min-1 and airflow rate of 10 L min-1. Structural analysis confirms the pure orthorhombic structure formation of the V2O5 material, while FE-SEM images show a well-organized 3D spongy-like porous architecture. The excellent conformality of the ASPD enables the deposition of high-aspect-ratio 3D structured nanoporous V2O5 electrodes for next-generation supercapacitor applications. The hierarchical structured 3D nanoporous V2O5 electrode exhibits superior electrochemical performance in a 1M Na2SO3 electrolyte. Within the potential window 0 to -1.3 V, the electrode archives the highest specific capacitance (SC) of 453.32 F g-1 and also retains 86% of its capacitance after 5000 cycles. These properties mainly originate from the crystallinity, 3D nanoporous structure, and fast and easy ionic intercalation through the material. Furthermore, a symmetric supercapacitor device using this electrode is fabricated and which yields outstanding electrochemical performance. Overall, the results highlight the potential of 3D nanoporous V2O5 as an outstanding electrode material for next-generation supercapacitor applications. Graphical illustration of electrochemical charging-discharging behavior and possible reaction on vanadium oxide electrode for next-generation supercapacitor application.image