Growth and Electrochemical Properties of Single-Crystalline V2O5 Nanorod Arrays

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 mm 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 Liþ intercalation. The relationships between electrochemical property, nanoand microstructure, and growth mechanisms have been discussed. [DOI: 10.1143/JJAP.44.662]