Copper oxide nanowires with an average length of 7.4 mu m are prepared by in-situ thermal oxidation at 500 degrees C for 6 h in air, and their lithium storage performances are promoted by a further ammonia treatment. The morphologies, structures and lithium storage properties of copper oxide nanowire arrays are investigated by X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy and a series of electrochemical measurements. The results show that after the reprocessing, the CuO nanowire arrays exhibit a higher reversible capacity of 645 mAhg(-1) after 100 cycles at a current density of 50 mAg(-1), excellent cyclability and high-rate capability. The good electrochemical performance and simple preparation process make it a promising anode material for lithium-ion batteries. (C) 2014 Elsevier Ltd. All rights reserved.