Electrochemical Performance of V2O5//f-CNT Asymmetric Flexible Device for Supercapacitor Application

The advancement of flexible supercapacitors has been constrained by the inherent difficulty of fabricating flexible electrodes. In this work, the V₂O₅ nanostructures were synthesized at different temperatures (120–200 °C) via hydrothermal treatment, followed by calcination, resulting in materials with high porosity and optimized electrochemical properties. The fabricated electrode (synthesized V₂O₅ at 180 °C) shows a maximum capacitance (178.5 F g⁻¹ at 1 A g⁻¹ current density) compared to other prepared samples 1 in a 1.0 M Na₂SO₄ aqueous electrolyte. For practical applications, V₂O₅ nanostructures were integrated with f-CNTs to fabricate the V₂O₅//f-CNT asymmetric supercapacitor device, achieving a specific capacitance of 104.4 F g⁻¹ at 1 A g⁻¹ within a 1.6 V voltage window, signifying improved charge storage capabilities. The device achieved an energy density of 37.12 Wh kg⁻¹ and a power density of 800 W kg⁻¹ at 1 A g⁻¹. The synergistic integration of Faradaic reactions from V₂O₅ with the EDL capacitance of f-CNTs enabled the device to retain 91.2% of its capacitance after 2000 GCD cycles, with enhanced performance sustained up to 5000 cycles. Furthermore, the device demonstrated remarkable flexibility, losing only 4.3% of its capacitance when bent at a 90° angle, underscoring its potential as a high-performance energy storage solution.

Graphical Abstract