Flute‐like Fe₂O₃ Nanorods with Modulating Porosity for High Performance Anode Materials in Lithium Ion Batteries

Abstract

Abstract Flute‐like Fe 2 O 3 nanorods with tunable porosity are obtained by facile hydrothermal process and subsequent calcination. The morphology, porosity and structural stability of Fe 2 O 3 nanorods are effectively controlled by a two‐step strategy at nano/micrometer scale. The introduction of F ions promotes the formation of nanorod‐like iron hydroxide precursors, which are annealed at 400, 500 and 600 ° C to obtain Fe 2 O 3 . The pore size increases with the annealing temperature. When tested as anode material of lithium ion batteries (LIBs), the porous Fe 2 O 3 nanorods obtained by annealing at 500 ° C exhibit better cycling stability and rate capability than those obtained at 400 and 600 ° C. Most impressively, it delivers a capacity of 707.4 and 687.7 mAh g −1 at 1 and 2 A g −1 after 200 cycles, respectively. Compared to the other two samples, the Fe 2 O 3 nanorods with optimized pore distribution exhibit robust porous framework, which contributes to the structural and electrochemical stability of electrode. The porous framework can effectively alleviate the severe volume expansion/contraction and avoid pulverization of active materials, resulting in outstanding reversibility and rate capability. This work will benefit the design of novel materials for LIBs.