ion batteries

sodium-ion batteries

lithium storage

sodium ion

specific capacity

batteries sibs

reversible capacity

anode material

cycling stability

Journal of Energy Chemistry

The hybrid nanotube arrays composed of nitrogen/sulfur-codoped carbon coated sulfur-doped TiO 2 nanotubes exhibit excellent sodium-storage performance due to the unique structural and compositional advantages. Titanium dioxide (TiO 2 ) has been investigated broadly as a stable, safe, and cheap anode material for sodium-ion batteries in recent years. However, the poor electronic conductivity and inherent sluggish sodium ion diffusion hinder its practical applications. Herein, a self-template and in situ vulcanization strategy is developed to synthesize self-supported hybrid nanotube arrays composed of nitrogen/sulfur-codoped carbon coated sulfur-doped TiO 2 nanotubes (S-TiO 2 @NS-C) starting from H 2 Ti 2 O 5 ·H 2 O nanoarrays. The S-TiO 2 @NS-C composite with one-dimensional nano-sized subunits integrates several merits. Specifically, sulfur doping strongly improves the Na + storage ability of TiO 2 @C-N nanotubes by narrowing the bandgap of original TiO 2 . Originating from the nanoarrays structures built from hollow nanotubes, carbon layer and sulfur doping, the sluggish Na + insertion/extraction kinetics is effectively improved and the volume variation of the electrode material is significantly alleviated. As a result, the S-TiO 2 @NS-C nanoarrays present efficient sodium storage properties. The greatly improved sodium storage performances of S-TiO 2 @NS-C nanoarrays confirm the importance of rational engineering and synthesis of hollow array architectures with higher complexity.

Robust S-doped TiO2@N,S-codoped carbon nanotube arrays as free-binder anodes for efficient sodium storage