V2ON thin film has been successfully fabricated by reactive dc sputtering method and annealing process and was investigated for its electrochemistry with lithium. The reversible discharge capacities of V2ON/Li cells cycled between 0.01 and 4.0 V were found in the range of 803-915 mAh g(-1) during the first 50 cycles. By using ex situ scanning electron microscopy, transmission electron microscopy, selected-area electron diffraction and X-ray photoelectron spectroscopy measurements, the reversible transformation between nanocrystalline V2ON and well dispersed V, Li2O, Li3N nano-composites were revealed in the lithium electrochemical reaction. V2ON thin film exhibits high reversible capacity and good cycle performance with remarkable lower polarization than VN thin film. (C) 2011 Elsevier Ltd. All rights reserved.