Size-Controlled Hollow Spheres of C/alpha-Fe2O3 Prepared through the Quasiemulsion-Templated Method and Their Electrochemical Properties for Lithium-Ion Storage

Abstract

In this paper, alpha-Fe2O3 hollow spheres in different sizes were successfully synthesized through a glycerol emulsion template method for use as efficient electrode materials in lithium-ion batteries. The sizes of alpha-Fe2O3 hollow sphere could be easily controlled by adjusting the amount of glycerol over the Fe precursor during the hydrothermal synthesis process. A thin carbon layer was subsequently coated on the surface of alpha-Fe2O3 hollow spheres through hydrothermal treatment with glucose for the carbonization process, in which the carbon phases could serve as a conductive layer for the efficient charge transfer, but also as a buffer layer for the accommodation of volume vibration of the electrode material during cycling. The carboncoated alpha-Fe2O3 hollow sphere electrode showed a high discharge capacity of approximately 1452 mAhg(-1) with a capacity increase of at least 32% compared to that of alpha-Fe2O3 hollow spheres without the carbon coating at the 50th cycle. The stability and cycling performance were also significantly improved by the presence of the carbon layer, indicating that the C/alpha-Fe2O3 hollow sphere could be a promising metal-oxide anode material for lithium-ion batteries.