High electrochemical performance of Fe₂O₃@OMC for lithium-ions batteries

Fe₂O₃@OMC (ordered mesoporous carbon) is synthesized using Fe-MOFs (metal-organic frameworks). The Fe₂O₃@OMC pore size is mostly concentrated at approximately 2-4 nm. Compared to traditional OMC or carbonized Fe-MOFs, Fe₂O₃@OMC demonstrates a higher capacity (the capacity remains at 1176.6 mAh g^-1 after 500 cycles under a current density of 0.1 A g^-1) and a longer cycle life. The first cycle capacity of Fe₂O₃@OMC is ultrahigh at 2448.6 mAh g^-1, and the reversible capacity is 1294.1 mAh g^-1. Fe₂O₃@OMC maintains a good performance under current densities of 0.1 A g^-1, 0.2 A g^-1, 0.5 A g^-1, 1 A g^-1, 2 A g^-1, and 5 A g^-1, with electric capacities of 1100.8 mAh g^-1, 1017.6 mAh g^-1, 849.3 mAh g^-1, 690.7 mAh g^-1, 506.7 mAh g^-1, and 272.1 mAh g^-1, respectively. Thus, the material has good rate performance. Combining iron oxide and MOFs is helpful to improve the capacity performance.