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

Abstract

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 ~4% vertical expansion and ~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.

Multi-Layer TiO2−x-PEDOT-Decorated Industrial Fe2O3 Composites as Anode Materials for Cycle-Performance-Enhanced Lithium-Ion Batteries

“…To meet the demand of the high energy storage of Li-ion batteries, a large number of anode materials, such as silicon [14,15] and transition metal oxides [16][17][18] etc., have been developed to substitute graphite. Iron oxide (Fe 2 O 3 ) has been demonstrated to be one of the most promising candidates due to its low cost, considerable specific capacity (~1000 mAh/g), and environmental friendliness [19][20][21][22]. However, the anode faces the problem of rapid capacity decay and a low Coulombic efficiency, which is due to its large volume expansion during cycling, particle agglomeration, and the inherently low electrical conductivity of the metal oxide.…”