A nanocomposite of molybdenum trioxide (MoO3) nanobelts coated with polypyrrole was prepared as an anode material for aqueous rechargeable sodium batteries (ARSBs). When nanowire Na-0.35 MnO2 is used as the cathode, the ARSB can deliver an energy density of 20 Wh kg(-1) at 80W kg(-1) and even maintain 18 Wh kg(-1) at 2.6 kW kg(-1) in 0.5 mol L-1 Na2SO4 aqueous electrolyte, suggesting a good rate capability that can be comparable with supercapacitors. In addition, its cycling behavior is greatly improved compared with the virginal MoO3. This will provide a new direction to explore non-carbon anode materials for ARSBs with excellent electrochemical performance. This good performance exhibits that this battery will be a promising candidate for the storage of solar and wind energies. (C) 2013 Elsevier Ltd. All rights reserved.