Uniform hematite nanocapsules based on an anode material for lithium ion batteries

Uniform α-Fe2O3 nanocapsules with a high surface area were synthesized by a novel wrap–bake–peel approach consisting of silica coating, heat treatment and finally the removal of the silica coating layer. The length, diameter and shell thickness of the hematite nanocapsules were about 65, 15 and 5 nm, respectively. The electrochemical properties of the α-Fe2O3 nanocapsules were investigated by cyclic voltammetry and charge/discharge measurements. The α-Fe2O3 nanocapsules showed a high reversible capacity of 888 mAh/g in the initial cycle and 740 mAh/g after 30 cycles as well as good capacity retention. This excellent electrochemical performance was attributed to the high surface area, thin shell and volume space of the hollow structure.