Porous one-dimensional carbon/iron oxide composite for rechargeable lithium-ion batteries with high and stable capacity

Hematite iron oxide (α-Fe₂O₃) is considered to be a prospective anode material for lithium-ion batteries (LIBs) because of its high theoretical capacity (1007 mAh g⁻¹), nontoxicity, and low cost. However, the low electrical conductivity and large volume change during Li insertion/extraction of α-Fe₂O₃ hinder its use in practical batteries. In this study, carbon-coated α-Fe₂O₃ nanofibers, prepared via an electrospinning method followed by a thermal treatment process, are employed as the anode material for LIBs. The as-prepared porous nanofibers with a carbon content of 12.5 wt% show improved cycling performance and rate capability. They can still deliver a high and stable capacity of 715 mAh g⁻¹ even at superior high current density of 1000 mA g⁻¹ after 200 cycles with a large Coulombic efficiency of 99.2%. Such improved electrochemical performance can be assigned to their unique porous fabric structure as well as the conductive carbon coating which shorten the distance for Li ion transport, enhancing Li ion reversibility and kinetic properties. It is, therefore, demonstrated that carbon-coated α-Fe₂O₃ nanofiber prepared under optimized conditions is a promising anode material candidate for LIBs. - Graphical abstract: Carbon-coated α-Fe₂O₃ nanofibers are employed as anode material to achieve high and stable electrochemical performance for lithium-ion batteries, enhancing their commercial viability. - Highlights: • α-Fe₂O₃/C nanofibers were fabricated by electrospinning and thermal treatment. • α-Fe₂O₃/C nanofibers exhibit stable cyclability and good rate capability. • α-Fe₂O₃–C nanofibers maintain high capacity at 1000 mA g⁻¹ for 200 cycles. • A capacity retention of 99.2% is achieved by α-Fe₂O₃–C nanofibers after 200 cycles.