Flocculant-assisted synthesis of Fe2O3/carbon composites for superior lithium rechargeable batteries

Highlights: ► A facile flocculant-assisted fabrication of Fe2O3/C composite. ► Carboxymethylcellulose acts simultaneously as the flocculant and carbon source. ► A high capacity of 497 mA h g−1 at 1000 mA g−1 over 100 cycles is retained. ► Fe2O3/C anode exhibits excellent rate capability and cyclability. -- Abstract: High-performance iron oxide/carbon (Fe2O3/C) composites for lithium-ion batteries are synthesized by the combination of flocculant-assisted process and thermo-chemical treatment. Carboxymethylcellulose is used simultaneously as the flocculant and carbon source. This facile and scalable method lends itself to the fabrication of other metal oxide/carbon composites based on the flocculation mechanism. The lithium storage mechanism and cycling performance of Fe2O3/C composites are investigated by cyclic voltammetry and charge–discharge tests. As the rates increase from 50 to 1000 mA g−1, the composites display high charge capacities of 834 mAh g−1 for the first cycle at 50 mA g−1 and 497 mAh g−1 at 1000 mA g−1 over 100 cycles. Excellent rate capability and cyclability are ascribed presumablely to the isolation and buffer functions of the conductive carbon matrix against particle aggregation and large volume variety upon cycling.