Fe2O3/LaFeO3 nanocomposites derived from MOFs as high-performance anodes for lithium-ion batteries

Metal-organic frameworks (MOFs), as an emerging porous material, have attracted much attention due to their extremely large specific surface area and extremely high porosity. In recent years, the synthesis of transition metal oxides (TMOs) using MOFs as precursors has become a research hotspot. However, the iron oxide (Fe_xO_y) compounds derived from Fe-MOFs still face problems such as low electrical conductivity and significant volume changes during charging and discharging in practical applications. For this purpose, in this study, the Fe–La-MOFs precursors were prepared by solvothermal method, and nanocomposites of Fe₂O₃, 10Fe₂O₃/LaFeO₃, 20Fe₂O₃/LaFeO₃ and 30Fe₂O₃/LaFeO₃ were synthesized by calcination of the as-prepared MOFs. By introducing the inexpensive rare earth element La, the lithium storage performance and structural stability of the material have been effectively enhanced. The experimental results show that at the optimal doping ratio, the 20Fe₂O₃/LaFeO₃ composite material exhibits excellent electrochemical performance, with a reversible capacity of up to 742.59 mAh g⁻¹ (after 100 cycles), which is much higher than 407.1 mAh g⁻¹ of pure Fe₂O₃. Importantly, the presence of LaFeO₃ enables the material to maintain 616.39 mAh g⁻¹ at 1 A g⁻¹, which effectively alleviates the volume expansion problem of Fe₂O₃ materials during the charging and discharging process. The 20Fe₂O₃/LaFeO₃ nanocomposites derived from iron-based MOFs are expected to become an ideal choice for high-performance lithium-ion battery anode materials due to their outstanding electrochemical performance and promising application prospects.