One-Step Route to Fe₂O₃ and FeSe₂ Nanoparticles Loaded on Carbon-Sheet for Lithium Storage

Iron-based anode materials, such as Fe₂O₃ and FeSe₂ have attracted widespread attention for lithium-ion batteries due to their high capacities. However, the capacity decays seriously because of poor conductivity and severe volume expansion. Designing nanostructures combined with carbon are effective means to improve cycling stability. In this work, ultra-small Fe₂O₃ nanoparticles loaded on a carbon framework were synthesized through a one-step thermal decomposition of the commercial C₁₅H₂₁FeO₆ [Iron (III) acetylacetonate], which could be served as the source of Fe, O, and C. As an anode material, the Fe₂O₃@C anode delivers a specific capacity of 747.8 mAh g^-1 after 200 cycles at 200 mA g^-1 and 577.8 mAh g^-1 after 365 cycles at 500 mA g^-1. When selenium powder was introduced into the reaction system, the FeSe₂ nano-rods encapsulated in the carbon shell were obtained, which also displayed a relatively good performance in lithium storage capacity (852 mAh g^-1 after 150 cycles under the current density of 100 mA·g^-1). This study may provide an alternative way to prepare other carbon-composited metal compounds, such as FeN_x@C, FeP_x@C, and FeS_x@C, and found their applications in the field of electrochemistry.