In this study, a facile one-pot solvothermal method was employed to synthesize a helical carbon nanofibers@titanium dioxide (TiO₂@HCNFs) composite, in which an anatase TiO₂ coating layer with an average thickness of 20 nm was grafted in situ onto the surface of HCNFs. As a novel anode material for sodium-ion batteries (SIBs), TiO₂@HCNFs retains a specific capacity of 193 mA h g⁻¹ over 100 cycles at a current density of 0.1 A g⁻¹, showing a significant enhancement; namely, a 187%, 148%, and 134% higher specific capacity than that obtained for pure HCNFs (103 mA h g⁻¹), pure TiO₂ (130 mA h g⁻¹) and a TiO₂-HCNFs mixture (143.5 mA h g⁻¹), respectively. In addition, a capacity of 120 mA h g⁻¹ can be maintained for TiO₂@HCNFs even at a high current density of 2 A g⁻¹. This excellent performance can be ascribed to the dual-phase combination of HCNFs/TiO₂ and the sophisticated carbon coil structure, which improves the conductivity of TiO₂ and shortens the distance for sodium-ion diffusion. Therefore, this work will bring about new possibilities for developing new anode materials for SIBs.

在本研究中，采用简便的一锅溶剂热法合成了螺旋状碳纳米纤维@二氧化钛（TiO ₂ @HCNFs）复合材料，其中平均厚度为 20 nm的锐钛矿型 TiO ₂涂层原位接枝到HCNF 的表面。作为钠离子电池（SIBs ）的新型负极材料，TiO ₂ @HCNFs在 0.1 A g ^-1的电流密度下在 100 次循环中保持了 193 mA hg ^-1的比容量，显示出显着的增强；即，比容量比纯 HCNF (103 mA hg ^-1 )、纯 TiO ₂ (130 mA hg ^-1 ) 和 TiO _{2 的}比容量高 187%、148% 和 134%-HCNFs 混合物（143.5 mA hg ^-1），分别。此外，即使在 2 A g ^-1的高电流密度下，TiO ₂ @HCNF也可以保持120 mA hg ^-1的容量。这种优异的性能可以归因于HCNFs/TiO ₂的双相结合和复杂的碳线圈结构，提高了TiO ₂的导电性并缩短了钠离子扩散的距离。因此，这项工作将为开发新的SIBs负极材料带来新的可能性。