Sol-gel-based template synthesis and Li-insertion rate performance of nanostructured vanadium pentoxide

We have prepared nanostructured electrodes of orthorhombic V2O5 using the template synthesis method. These electrodes were used to investigate the effects of Li-ion diffusion distance and surface area on V2O5 rate capability. Nanowires of V2O5 were prepared by depositing a precursor into the pores of microporous polycarbonate filtration membranes. This procedure yielded an ensemble of 115 nln diam. 2 mu m long nanowires of V2O5 which protruded from a V2O5 surface layer like the bristles of a brush. The galvanostatic discharge performance of these nanostructured V2O5 electrodes was compared to a thin-film electrode of similar V2O5 mass and geometric area. The Li+ storage capacity of the thin-film electrode was equivalent to that of the nanostructured electrode at low (C/20) discharge rates. However. at a rate of 200 C, the nanostructured electrode delivered three times the capacity of the thin film electrode. Above 500 C the nanostructured electrode delivered four times the capacity of the thin-film control electrode. (C) 1999 The Electrochemical Society. S0013-4651(98)12-028-1. All rights reserved.