Fabricating SiO2-coated V2O5 nanoflake arrays for high-performance lithium-ion batteries with enhanced cycling capability

Abstract

In the designed synthesis, hierarchical V₂O₅ nanoflake arrays were prepared via calcining NH₄VO₃ arrays. Then V₂O₅ arrays were coated with a porous SiO₂ layer. Finally, a unique pattern of SiO₂-coated V₂O₅ nanoflake arrays was obtained for the first time. This hierarchical and elaborate architecture possessed several impressive virtues, including a large surface-to-volume ratio, short diffusion paths of lithium ions, and strong physical adhesion between the current collector and active material. When acting as a binder-free electrode for lithium-ion batteries, the electrode exhibited a high capacity and good rate capability. At a current density of 0.1 A g⁻¹, a high capacity of 289 mA h g⁻¹ was obtained, and even at a high current rate of 4 A g⁻¹, a capacity of 175 mA h g⁻¹ could be still maintained. Remarkably, the hierarchical nanostructures sharply improved the cycling stability of the binder-free V₂O₅ electrode. As a result, a high reversible capacity of 256 mA h g⁻¹ is obtained after 500 cycles.