Electrodeposition of vanadium pentoxide on carbon fiber cloth as a binder-free electrode for high-performance asymmetric supercapacitor

Electrodeposition technique is a convenient and robust approach for the development of transition metal oxides as electrodes, particularly for supercapacitor applications. However, achieving uniform coating is difficult and relies on the constrained deposition parameters. Herein, we fabricated the binder-free spiral rope-like structured V₂O₅ on carbon fiber cloth (CFC) by simple and versatile electrodeposition method for high performance asymmetric supercapacitors. The deposition rate of V₂O₅ nanostructures on CFC was controlled by varying the electrodeposition duration. The resultant optimum duration (30 min) of the binder-free V₂O₅@CFC-30 electrode showed an excellent performance with a high areal capacitance of 354 mF/cm² in 1 M Na₂SO₄ aqueous electrolyte. Furthermore, the asymmetric supercapacitor (ASC) was developed using V₂O₅@CFC-30 as a positive electrode and O, N, S enriched activated carbon (O, N, S@AC) as a negative electrode. The ASC demonstrated a maximum device-specific capacitance of 57 F/g, excellent cyclic stability (~94%) even after 10,000 cycles and maximum specific energy (17.7 Wh/kg) and power (2728 W/kg). Furthermore, the flexible supercapacitor delivered maximum specific energy (13 Wh/kg) and power (3871 W/kg) with an outstanding capacity retention of 91% over 4000 cycles. This research makes the electrodeposition of V₂O₅ ideally suited for a binder-free, high performance supercapacitor applications.