A nanocomposite of MoO₃ coated with PPy as an anode material for aqueous sodium rechargeable batteries with excellent electrochemical performance

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_0.35MnO₂ is used as the cathode, the ARSB can deliver an energy density of 20 Wh kg^-1 at 80 W 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.