TiO₂ encapsulated free-standing SbVO₄ nanotube arrays: As durable anode materials for lithium/sodium-ion batteries

Antimony anode has attracted increasing advertence in lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) with its suitable voltage platform and high theoretical capacity. Nevertheless, volume expansion and exfoliation severely affect the electrochemical performance. Herein, a performance-oriented electrode structure is proposed, which is a sort of three-dimensional (3D) TiO₂@SbVO₄@TiO₂ nanotube arrays integrated additive-free electrode with high orderliness, exceptional para-vertical alignment, and appropriate interval spacing. Benefiting from these structural merits, the 3D TiO₂@SbVO₄@TiO₂ nanotube-arrays integrated anode employed for LIBs supplies an invertible specific capacity as high as 448 mAh·g⁻¹ at 2 A·g⁻¹ after 1890 cycles and an exceptional high-rate capacity of 356 mAh·g⁻¹ at 10 A·g⁻¹. Furthermore, as an anode for SIBs, it can also reveal an invertible specific capacity of 288 mAh·g⁻¹ at 1 A·g⁻¹ after 1000 cycles and brilliant rate performance with a specific capacity of 160 mAh·g⁻¹ at 10 A·g⁻¹. These excellent electrochemical properties lay the foundation for more applications of 3D nanotube arrays integrated additive-free electrodes in energy storage devices.