TiO₂ Nanotubes Array on Carbon Cloth as a Flexibility Anode for Sodium-Ion Batteries

In this work, three-dimensional (3D) TiO₂ nanotubes (NTs) on carbon cloth (CC) (TiO₂ NTs/CC) were synthesized by a method involving formation of a ZnO@TiO₂ nanorod (NRs) on CC (ZnO@TiO₂ NRs/CC) structure and a subsequent chemical etching process for ZnO NRs template. The 3D TiO₂ NTs/CC were applied as flexible anodes for sodium ion batteries (SIBs). The TiO₂ NTs/CC yielded high specific capacity and good cycling stability, superior to that of some reported TiO₂ nanocomposites. The TiO₂ NTs/CC delivered a reversible capacity of 260 mA·h·g^-1 and 85.1% capacity retention over 150 cycles at current density of 0.25 C (1 C = 335 mA·g^-1). It also exhibited high rate capacity of 200 mA·h·g^-1 at 0.5 C. Even at a high rate of 1.0 C, the TiO₂ NTs/CC can still maintain a high capacity of 100 mA·h·g^-1. Moreover, it was observed that the electrochemical performance for the TiO₂ NTs/CC was much better than that (150 mA·h·g^-1 for up to 150 cycles) of a solid TiO₂ NRs/CC counterpart, which also demonstrated the capacity enhancement and good cycling stability.