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

Abstract

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.