Nb2O5 nanorod array films were synthesized by a facile hydrothermal process using niobium metal foil and NH4F as precursors. The Nb2O5 nanorods stand on the niobium metal foil substrate and are less than 100 nm in diameter and about 1 mu m in length. X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM) characterizations indicate that these nanorods have orthorhombic structure and grew longitudinally along < 0 0 1 > direction. The nanorod growth mechanism was discussed. Thermal annealing at a temperature below 500 degrees C did not change the microstructure of nanorods but improve the crystallinity. The Nb2O5 nanorod array films have been tested as cathode material for lithium battery, which showed a good specific capacity up to 380 mAhg(-1) even after 50 charge/discharge cycles. (C) 2011 Elsevier B.V. All rights reserved.