Nickel vanadate microspheres with numerous nanocavities synthesized by spray drying process as an anode material for Li-ion batteries

For use in next-generation energy storage applications, including electric vehicles, capacity and cycle life of lithium ion batteries need further improvement. Moreover, to achieve fast lithiation kinetics of the electrode materials, high power density and quick charging ability are necessary. Nickel vanadate (Ni₃V₂O₈) microsphere with tens of nanocavities is one of candidates for anode materials suitable for lithium ion batteries. The synthesis of microspheres is possible by a pilot-scale spray drying process and facile one-step oxidation heat treatment. Dextrin, which is present in the microspheres after spray drying process, plays a key role in the formation of nanocavities. Oxidation at different temperatures yields carbon composite microspheres with nanocavities and hierarchical Ni₃V₂O₈ microspheres with nanocavities. The nanocavities facilitate electrolyte contact with the electrode material and alleviate volume change during lithiation/delithiation. The merits of the nanocavities in the Ni₃V₂O₈ microspheres enable a high discharge capacity of 1045 mA h g⁻¹ for the 2nd cycle at 1 A g⁻¹ and long cycle life. Furthermore, Ni₃V₂O₈ microspheres deliver a high discharge capacity of 612 mA h g⁻¹ at a high current density of 6 A g⁻¹.