Synthesis of MIL-101-derived bimetal–organic framework and applications for lithium-ion batteries

In the present study, to broaden the application of metal–organic framework (MOF) materials in electronic functional materials, a simple solvothermal method was adopted to introduce bimetals, and metal–organic framework compounds (MIL-101 (Fe), MIL-101 (Fe, Co), MIL-101 (Fe, Cu)) acted as the templates. The hollow structures of Fe2O3, CoFe2O4, and CuFe2O4 were formed through the simple calcinations at 600 °C for 3 h in Ar atmosphere. When the mentioned materials exhibiting hollow structures were tested as the negative electrode of a lithium-ion battery, introducing bimetals was reported to be able to improve their electrochemical performance. For instance, CoFe2O4 and CuFe2O4 were cycled 300 times under a high current density of 1000 mA/g, and the reversible capacity remained to be 978 mAh/g and 774 mAh/g. When 200 cycles were performed under a current density of 200 mA/g, these materials exhibited high specific capacities of 1118 mAh/g and 1155 mAh/g.