Hierarchical-Structured Fe2O3 Anode with Exposed (001) Facet for Enhanced Lithium Storage Performance

The hierarchical structure is an ideal nanostructure for conversion-type anodes with drastic volume expansion. Here, we demonstrate a tin-doping strategy for constructing Fe2O3 brushes, in which nanowires with exposed (001) facets are stacked into the hierarchical structure. Thanks to the tin-doping, the conductivity of the Sn-doped Fe2O3 has been improved greatly. Moreover, the volume changes of the Sn-doped Fe2O3 anodes can be limited to similar to 4% vertical expansion and similar to 13% horizontal expansion, thus resulting in high-rate performance and long-life stability due to the exposed (001) facet and the unique hierarchical structure. As a result, it delivers a high reversible lithium storage capacity of 580 mAh/g at a current density of 0.2C (0.2 A/g), and excellent rate performance of above 400 mAh/g even at a high current density of 2C (2 A/g) over 500 cycles, which is much higher than most of the reported transition metal oxide anodes. This doping strategy and the unique hierarchical structures bring inspiration for nanostructure design of functional materials in energy storage.

Automated summary

In this study, a tin-doping strategy was used to construct a hierarchical structure of stacked nanowires with exposed (001) facets in Fe2O3 brushes. The tin-doping greatly improved the conductivity of the Sn-doped Fe2O3. Furthermore, the volume changes of the Sn-doped Fe2O3 anodes were limited to approximately 4% vertical expansion and approximately 13% horizontal expansion, resulting in high-rate performance and long-life stability due to the exposed (001) facet and unique hierarchical structure. This doping strategy and the unique hierarchical structures provide inspiration for nanostructure design of functional materials in energy storage.