V₂O₅ nanoribbons for improved cyclic stability in aqueous K⁺- ions based supercapacitor

V₂O₅ due to its layered structure, variable oxidation-state reversibility, and high abundance, is a promising electrode material for supercapacitors. However, low conductivity and slow kinetics of bulk V₂O₅ hinders its practical applications. In comparison to bulk V₂O₅, nanostructured V₂O₅ offer several advantages, including a high surface-to-volume ratio, availability of more electroactive sites, and facile movement of electrolyte ions, which improve the electrochemical performance of the material. Here, we report the synthesis of V₂O₅ ultralong nanoribbons using a single-step hydrothermal process. The synthesized nanoribbons showed capacitive retention of 84.5% over 1000 cycles with highest specific capacitance of 140 Fg⁻¹ at 5 mVs⁻¹. An asymmetric two-electrode device was fabricated, which showed a specific capacitance of 65 Fg⁻¹ at 5 mVs⁻¹ and a flat retention response of approximately 77% up to1000 charge-discharge cycles. The fabricated device showed maximum energy and power density of 17 WhKg⁻¹ and 1200 WKg⁻¹, respectively. The mixed oxidation states and ultralong morphology of the nanoribbons positively impact the overall electrochemical performance of these nanostructures. Our study indicate that V₂O₅ nanoribbons can be used as efficient electrode materials for supercapacitors.