Growth and Electrochemical Properties of Single-Crystalline V2O5 Nanorod Arrays

Abstract

Growth and electrochemical properties of single-crystalline vanadium pentoxide (V₂O₅) nanorod arrays were investigated. Vanadium pentoxide nanorod arrays were grown by electrochemical deposition, surface condensation induced by a pH change and sol electrophoretic deposition. Uniformly sized vanadium oxide nanorods with a length of about 10 µm and diameters of 100 or 200 nm were grown over a large area with near-unidirectional alignment. Transmission electron microscopy (TEM) micrographs and electron diffraction patterns of V₂O₅ nanorods clearly show the single-crystalline nature of nanorods fabricated via all three growth routes with a growth direction of [010]. The growth mechanisms of single-crystal V₂O₅ nanorods have been discussed. Electrochemical analysis revealed that nanorod array electrodes possess significantly improved storage capacity and charge/discharge rate with approximately 5 times higher applicable current density than those of sol-gel derived films. Furthermore, for a given current density, the nanorod array electrode can intercalate up to 3.5 times higher concentration of Li⁺ intercalation. The relationships between electrochemical property, nano- and microstructure, and growth mechanisms have been discussed.