Facile synthesis of iron-based compounds as high performance anode materials for Li-ion batteries

Iron oxide@C composites and lithium ferrites were synthesized by a cotton-template method as anode materials for Li-ion batteries. alpha-Fe2O3@C composites with 3-D porous hollow secondary structures were prepared by directly burning the cotton containing the iron salt (FeCl3 or Fe(NO3)(3)) in air, and the Fe3O4@C composites with similar structures were obtained by annealing alpha-Fe2O3@C under a N-2 atmosphere. alpha-LiFeO2 and alpha-LiFe5O8 particles with sizes of 100-500 nm were also prepared using a similar method. Electrochemical measurements showed that all these samples demonstrated good electrochemical performances as Li-ion battery anodes, especially alpha-Fe2O3@C derived from Fe(NO3)(3), which delivers a high reversible capacity of 990 mA h g(-1) at 100 mA g(-1) after 50 cycles. Both the porous hollow secondary structure and the suitable amount of amorphous carbon are significant for the electrochemical performances of the iron oxide@C composites. Such a method is simple, rapid and inexpensive and may facilitate the preparation of other high performance electrode materials with porous hollow structures.