Controllable synthesis of Fe2O3-carbon fiber composites via a facile sol-gel route as anode materials for lithium ion batteries

Abstract

The Fe2O3-carbon fiber composites were prepared by a facile sol-gel method. The uniform distribution of Fe2O3 grains on the surface of carbon fibers was confirmed by field emission scanning electron microscopy and transmission electron microscopy. The impact of the Fe2O3 content in composite materials on electrochemical performance was also investigated in this study. The results show that the capacity degradation during cycling is associated with the content of Fe2O3 in composite materials. Comparative study of three composite samples with different Fe2O3 contents revealed that the best electrochemical performance with good cycling stability, high reversible capacity and improved rate capability was exhibited by the Fe2O3@carbon fiber sample. Even after 150 cycles at a constant current density of 50mAg−1, a high reversible discharge capacity of 634mAhg−1 can be achieved, which is comparable to its theoretical value (607mAhg−1). More importantly, the one-dimensional nanofibrous structure can be well preserved even after a long-time charge/discharge process over to 50 cycles, which demonstrates the structural robustness of the composite materials. The morphological robustness and excellent electrochemical performance of the Fe2O3@carbon fiber hybrid show its promise as an anode material for high-performance lithium-ion batteries (LIBs).