Nanocrystallites of vanadium pentoxide were synthesized by the hydrothermal treatment of electrospun composite nanofibers. Each crystallite of dimension <= 100 nm was found to be a single crystal of delta-phase H(x)V(4)O(10)center dot nH(2)O. The crystallinity and morphology was maintained on heating to 500 degrees C when V(2)O(5) was formed. The electrochemical capacity of the nano-V(2)O(5) in a lithium cell was found to be above 350 mAh/g. The columbic efficiency is close to 100% when small amounts of lithium bis(oxalato)borate is added to the LiPF(6) electrolyte. (C) 2008 Elsevier B.V. All rights reserved.