Electrodeposited thick coatings of V2O5 on Ni foam as binder free electrodes for supercapacitors

Thick coatings, up to few microns, of the active material are necessary for the preparation and commercialization of electrode materials for energy storage applications, as thin layers of active material drains out of the current collector after a few cycles. Moreover, larger mass loading of the active material is required for high energy density pseudocapacitor applications as more active material involves more redox reactions to store large amount of charge. This study reports thick electrodeposits of vanadium pentoxide (V2O5) on nickel foam substrate and its evaluation as supercapacitor electrode material. Vanadium pentoxide with thickness of 3–5 μm were successfully electrodeposited (potentiostatically and galvanostatically) on metallic nickel foam to obtain potentiostatically electrodeposited V2O5 on nickel foam (PE-V2O5Ni) and galvanostatically electrodeposited V2O5 on nickel foam (GE-V2O5Ni), respectively. The PE-V2O5Ni electrode with layered morphologies exhibits more charge storage and discharge capability than spherically dense morphologies of GE-V2O5Ni electrodes. The synthesized electrode materials were structurally, morphologically and chemically characterized through X-ray diffractometer, X-ray photoelectron spectroscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy. The PE-V2O5Ni and GE-V2O5Ni exhibited gravimetric capacitance of 657 and 421 F g−1 with tremendous stability in the polypropylene carbonate electrolyte.