Electrodeposition of vanadium oxides at room temperature as cathodes in lithium-ion batteries

Abstract

Electrodeposition of vanadium pentoxide coatings was performed at room temperature and a short growth period of 15 min based on an alkaline solution of methanol and vanadyl (III) acetyl acetonate. All samples were characterized by X-ray diffraction, Raman spectroscopy, field-emission scanning electron microscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. The current density and electrolyte concentration were found to affect the characteristics of the as-grown coatings presenting enhanced crystallinity and porous structure at the highest values employed in both cases. The as-grown vanadium pentoxide at current density of 1.3 mA·cm -2 and electrolyte concentration of 0.5 M indicated the easiest charge transfer of Li + across the vanadium pentoxide/electrolyte interface presenting a specific discharge capacity of 417 mAh·g -1 , excellent capacitance retention of 95%, and coulombic efficiency of 94% after 1000 continuous Li + intercalation/deintercalation scans. One may then suggest that this route is promising to prepare large area vanadium pentoxide electrodes with excellent stability and efficiency at very mild conditions.