Solution Synthesis and Electrochemical Properties of V 2 O 5 Nanostructures

We have prepared Ni-V 2 O 5 -nH 2 O core-shell nanocable arrays for Li + intercalation applications. Ni-V 2 O 5 ·nH 2 O nanocables were prepared via formation of Ni nanorod arrays through the template based electrochemical deposition, followed by coating of V 2 O 5 ·nH 2 O on Ni nanorods through electrophoretic deposition. Transmission electron microscopy (TEM) micrograph clearly shows the Ni core was covered completely by a V 2 O 5 ·H 2 O shell. Electrochemical analysis demonstrates that in a current density of 1.6 A/g, the Li + intercalation capacity of Ni-V 2 O 5 ·nH 2 O nanocable array is approximately 10 times higher than that of single-crystal V 2 O 5 nanorod array and 20 times higher than that of sol-gel-derived V 2 O 5 film. Both energy density and power density of such nanocable-array electrodes are higher than the V 2 O 5 film electrode by at least one order of magnitude. Such significant improvement in electrochemical performance is due to the large surface area and short diffusion path offered by the nanostructured V 2 O 5 ·H 2 O.