Synthesis of mixed-conducting carbon coated porous γ-Fe2O3 microparticles and their properties for reversible lithium ion storage

Disk-like alpha-Fe2O3 microparticles were synthesized by a facile hydrothermal method and transformed into iron oxide/carbon composites by chemical vapor deposition in an acetylene atmosphere. Through careful control of the reaction time, carbon-coated porous gamma-Fe2O3 microparticles with reversible Li+ storage properties were produced. The measured specific capacity after 40 cycles of charge and discharge was in excess of 900 mA h g(-1) and rate capability was very good up to a current density of 2000 mA g(-1). The good performance in Li+ storage could be attributed to the combination of porosity and a uniform nanocarbon coating which provided mixed-conducting properties for the fast diffusion of both lithium ions and electrons.