Electrochemical performance of V2O5//f-CNT asymmetric flexible device for supercapacitor application

Abstract

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. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2025.