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 FeCl 3 ·6H 2 O and MnCl 2 ·4H 2 O 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– x Mn x O 3, and a biphasic composite consisting of hematite (α-Fe 2 O 3 ) and manganese ferrite (MnFe 2 O 4 ) phases. The properties of the nanomaterials in the three structures display significant differences. Notably, the α-Fe 2 O 3 /MnFe 2 O 4 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-Fe 2 O 3 /MnFe 2 O 4 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.