Structure-Regulated α-Fe2O3/MnFe2O4 Nanomaterials for Lithium-Ion Battery Anodes

The structural differences in electrode materials significantly influence the electrochemical performance of lithium-ion batteries (LIBs). In this work, three composite nanomaterials with different structures and compositions were synthesized by the coprecipitation method, using FeCl₃·6H₂O and MnCl₂·4H₂O as raw materials and water as the solvent, by regulating the calcination temperature of the precursors: a composite of iron oxide and manganese dioxide, a single hematite-phase α-Fe_2–xMn_xO₃, and a biphasic composite consisting of hematite (α-Fe₂O₃) and manganese ferrite (MnFe₂O₄) phases. The properties of the nanomaterials in the three structures display significant differences. Notably, the α-Fe₂O₃/MnFe₂O₄ electrode exhibits a more uniform particle size distribution and reduced agglomeration, with an average particle size of 79 nm, resulting in enhanced electrochemical performance. After 140 cycles at a current density of 0.1 A g^–1, the α-Fe₂O₃/MnFe₂O₄ electrode retains a reversible capacity of 1124 mAh g^–1. In the high-current test at 1 A g^–1, the electrode also exhibits excellent long-term cycling stability, maintaining a capacity of 408 mAh g^–1 after 1000 cycles. This study highlights the significant impact of subtle structural differences on electrochemical properties, offering insights into the development and modification of anode materials.