Synergistic effect on the improved lithium ion storage performance in the porous Fe2O3@Fe3C@C composite

Abstract

The porous Fe2O3@Fe3C@C composite was synthesized by a simple two-step thermal treatment and its structure, morphology, lithium ion storage performance and diffusion kinetics were discussed. Benefitting from the high theoretical capacity of Fe2O3 and fast kinetics of Fe3C, the Fe2O3@Fe3C@C composite exhibits a stable cycling capacity of 800.3 mAh g−1 after 100 cycles at 0.1 A g−1 with superior rate capability. The CV and in-situ EIS analysis results reveal that the Fe2O3@Fe3C@C composite has reversible redox reaction, stable solid electrolyte interphase films and low charge transfer resistance during the discharging and charging process. In addition, the lithium ion diffusion coefficients of the Fe2O3@Fe3C@C composite at different voltage states are investigated by GITT measurement. This work can provide an effective strategy for synthesis of metal oxide@metal carbide composite for lithium-ion batteries.