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

Abstract 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.