Summary
Vanadium redox flow batteries (VRFBs) are a promising technology for large-scale energy storage, but their performance depends heavily on the electrocatalytic activity of the carbon electrodes. This study develops an in-house electrospun electrocatalyst: an “urchin-like” composite of vanadium(III) oxide and carbon nanofibres (V₂O₃-CNF), produced from a vanadium-alkoxide precursor with polyvinylpyrrolidone as the carbon source, followed by thermal treatment. X-ray diffraction confirmed the rhombohedral V₂O₃ phase and electron microscopy revealed the characteristic spiky, urchin-like fibre morphology. Electrochemical tests (cyclic voltammetry and impedance spectroscopy) showed the V₂O₃-CNF composite is markedly more active than plain carbon nanofibres, with a very small peak-to-peak separation (≈0.02 V) and a much lower charge-transfer resistance (≈0.12 Ω cm²) for the vanadium redox couples.