CoFe2O4@C composite nanofiber films as self-standing anodes for lithium-ion batteries

In order to improve the comprehensive electrochemical performance of the CoFe2O4 electrode material for lithium-ion batteries (LIBs), the CoFe2O4 is integrated with highly conductive carbon materials. Flexible carbon nanofibers uniformly embedded with CoFe2O4 nanoparticles (CoFe2O4@CNFs) composite films were synthesized by an electrospinning and subsequent low-temperature carbonization process, and were characterized by XRD, TG, Raman, SEM, TEM, CV, GCD and EIS. The influence of CoFe2O4 content on the lithium storage performances of CoFe2O4@CNFs composites was investigated in detail. It is found that the as-prepared composite films directly used as self-standing anodes in lithium ion batteries exhibit good electrochemical properties. The incorporation of CoFe2O4 nanoparticles into CNFs can significantly improve their electrochemical performances, and the specific capacities first increase and then decrease with increasing CoFe2O4 content in CoFe2O4@CNFs, in which the CoFe2O4@CNFs-3 electrode with about 33.3% (w/w) CoFe2O4 presents an optimal specific capacity as well as better cycle stability and rate capability. The CoFe2O4@CNFs-3 electrode delivers a high reversible specific capacity of 611.4 mA·h·g−1 after 100 charge/discharge cycles at the current density of 0.1 A·g−1, corresponding to a capacity retention of 94% relative to the capacity of the second cycle. Moreover, even at a high current density of 2 A·g−1, the specific capacity still remains at 353.6 mA·h·g−1. The superior performance for CoFe2O4@CNFs-3 is mainly attributed to the proper combination and highly synergistic effect of electrochemically active CoFe2O4 and high conductive CNFs matrix. © 2022, Editorial Office of Acta Materiae Compositae Sinica. All right reserved.