NaV3O8 with superior rate capability and cycle stability as cathode materials for sodium-ion batteries

Development of novel cathode materials for sodium-ion batteries with high capacity and excellent cyclic performance is an exciting and demanding research direction. Herein, we demonstrate the synthesis of NaV3O8 via a rheological phase reaction method. The crystal structure and morphology of synthesized NaV3O8 were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The NaV3O8 powder, calcined at moderate temperature (350 °C) with more uniform and smaller nanorod/nanoplate morphology, and larger d001 spacing, exhibited excellent electrochemical performance as cathode material in sodium ion batteries. A specific discharge capacity of 120 mAh g−1 was achieved at the current density of 120 mA g−1, with exceptional cyclic performance (discharge capacity of 95 mAh g−1 at the 500th cycle). In addition, the NaV3O8 cathode demonstrated excellent rate capability and delivered specific capacity of 80.8 mAh g−1 at current density of 300 mA g−1. The superior electrochemical performance corresponds to the structural stability and faster ionic diffusion. The preliminary results indicate that NaV3O8 can be an alternative cathode material for high-performance sodium-ion batteries.