A carbon-free, three-dimensional network structured material composed of NiCo2O4 nanowires and Ni foam was synthesized by a facile method. When applied as the air electrode for the lithium-oxygen battery, the unique network structure enables the surface of nanowires highly accessible to the reactants and facilities the electron transport during the charge/discharge processes. A superior electrochemical performance including low charge overpotential and excellent cyclability are obtained. This work suggests the great potential of the carbon-free NiCo2O4@Ni as the air electrodes for lithium-oxygen batteries. (C) 2015 Elsevier Ltd. All rights reserved.