Reduced graphene oxide and nickel oxide composite was prepared by homogeneous coprecipitation and subsequent annealing. Characterizations show that NiO particles have a nanosheet-based microsphere structure and anchor uniformly on the surface of reduced graphene oxide platelets. As an anode for Li ion batteries, the composite has 1641 mAh g(-1) and 1097 mAh g(-1) specific capacities for the first discharge and charge, respectively, higher than the theoretical capacity of NiO. It shows an excellent cycling performance with a discharge capacity of 1041 mAh g(-1) after 50 cycles at a current of 100 mA g(-1), and has a good rate capacity with 727 mAh g(-1) at a current of 1600 mA g(-1). The results show a synergistic effect of nanosheet-based NiO microspheres and reduced graphene oxide platelets in the composite for improved electrochemical performance. (C) 2011 Elsevier Ltd. All rights reserved.