Anisotropic Vanadium Oxide Nanostructured Host Matrices for Lithium Ion Intercalation

Abstract

We report on unique high-volume low-dimensional V2O5-based turbostratic nanostructures, prepared using sol-gel synthetic methods from V2O5 · nH2O xerogels. Electrochemical intercalation of Li+ to form Li0.65V2O5 resulted in a maximum measured charge capacity of 1225 mAhg−1 as the β-LixV2O5 phase. Conductivities of the order of 10−3 S cm−1 were found on compressednanotube parallelepipedal samples, which exhibit an anisotropy factor of 70 at room temperature by preferential alignment of the nanotubes. The improved electrochemical properties observed in novel vanadium oxide nanostructured arrays are attributed to the increased volumetric density for ion intercalation, shorter diffusion paths to the intercalation sites, and a high degree of crystallinity of the individual nanotubular host structures.