A general synthesis of inorganic nanotubes as high-rate anode materials of sodium ion batteries

Inorganic tubular materials have an exceptionally wide range of applications, yet developing a simple and universal method to controllably synthesize them remains challenging. In this work, we report a vapor-phase-etching hard-template method that can directly fabricate tubes on various thermally stable oxide and sulfide materials. This synthesis method features the introduction of a vapor-phase-etching process to greatly simplify the steps involved in preparing tubular materials and avoids complicated post-processing procedures. Furthermore, the in-situ heating transmission electron microscopy (TEM) tech-nique is used to observe the dynamic formation process of TiO2-x tubes, indicating that the removal pro-cess of the Sb2S3 templates first experienced the Rayleigh instability, then vapor-phase-etching process. When used as an anode for sodium ion batteries, the TiO2-x tube exhibits excellent rate performance of 134.6 mA h g-1 at the high current density of 10 A g-1 and long-term cycling over 7000 cycles. Moreover, the full cell demonstrates excellent cycling performance with capacity retention of 98% after 1000 cycles, indicating that it is a promising anode material for batteries. This method can be expanded to the design and synthesis of other thermally-stable tubular materials such as ZnS, MoS2, and SiO2.(c) 2022 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Automated summary

This research presents a vapor-phase-etching hard-template method for the direct fabrication of tubes on various thermally stable oxide and sulfide materials. The method simplifies the preparation steps and avoids complicated post-processing procedures. The dynamic formation process of TiO2-x tubes was observed using in-situ heating transmission electron microscopy (TEM), and the TiO2-x tube showed excellent performance as an anode material for sodium ion batteries.