Bimetallic metal-organic framework derived Co3O4-CoFe2O4 composites with different Fe/Co molar ratios as anode materials for lithium ion batteries.

Developing high-performance electrode materials to replace a traditional graphite electrode is critical for the commercialization of lithium ion batteries, which however still remains a great challenge. Herein, we report a suitable method to synthesize a series of well-dispersed nanostructured Co3O4-CoFe2O4 composites (CCFs) from bimetallic metal-organic frameworks (BiMOFs) with varied Fe3+/Co2+ molar ratios. When used as anodes for lithium ion batteries, the CCF-12 composite exhibits a maximum initial discharge capacity of 1328 mA h g-1, a reversible capacity of 940 mA h g-1 at 100 mA g-1 after 80 cycles, and a better rate capability in comparison with those of pure Co3O4 and other CCF composites. The well-dispersed structure and small particle size are believed to mainly contribute to the outstanding electrochemical performance of CCF-12 electrodes.