Self-assembled three-dimensional hierarchical NiO nano/microspheres were fabricated via a hydrothermal route. The obtained NiO presents a micro-sized porous spherical morphology which is composed of a large number of primary NiO nanoparticles linked together with an ordered fashion. As anode material for lithium ion batteries, NiO nano/microspheres exhibit stable reversible capacity of over 700 mAh g(-1) and good rate capability. The superior electrochemical performance could be attributed to the merits of the unique three-dimensional hierarchical porous nano/microstructure. (C) 2014 Elsevier B.V. All rights reserved.