Synthesis and characterization of graphene-nickel oxide nanostructures for fast charge-discharge application

Graphene-metal oxide composites as anode materials for Li-ion batteries have been investigated extensively, but these attempts are mostly limited to moderate rate charge-discharge applications. Here, graphene-nickel oxide nanostructures have been synthesised using a controlled hydrothermal method, which enabled in situ formation of NiO with a coralloid nanostructure on graphene. Graphene/NiO (20%), graphene/NiO (50%) and pure NiO show stable discharge capacities of 185 mAh/g at 20 C (1 C = 300 mA/g), 450 mAh/g at 1 C, and 400 mAh/g at 1 C, respectively. High rate capability and good stability in prolonged charge-discharge cycling permit the application of the material in fast charging batteries for upcoming electric vehicles. To the best of our knowledge such fast rate performance of graphene/metal oxide composite as anode and such stability for pure NiO as anode have not been reported previously. (C) 2011 Elsevier Ltd. All rights reserved.