Fe2O3/Carbon nanocomposite as anode material for Li-ion cells

Abstract

To achieve sufficient energy density required for powering electric and hybrid electric automobiles, Li-ion cells using high capacity anode materials should be developed. Transition metal oxides are extensively being investigated as prospective anode materials for developing high capacity Li-ion cells. Depending on the type of energy storage mechanism, anode materials are classified as insertion, conversion and alloying type. Iron oxide is a conversion type anode material that has drawn extreme attention due to high specific capacity (theoretical capacity of Fe2O3 is 1007 mAh/g and that for Fe3O4 is 926 mAh/g), environmental friendliness and the possibility of using simple synthesis routes. Never-ending shuttling of lithium ions during charging and discharging (or lithiation and delithiation) is the mechanism of an ideal Li-ion cell. For efficient cell performance, electrode should retain its structural stability, porosity and conductivity after many cycles of charging and discharging. Present work deals with studies on the influence of pH of hydrothermal solution on the particle size distribution of Fe2O3, with a view to achieve structural stability for iron oxide/carbon nanocomposite, when used as anode active material in Li-ion cells. Cells assembled against lithium metal in half-cell configuration are used for electrochemical studies. Fe2O3/C nanocomposite anode shows initial discharge capacity of 880 mAh/g with a capacity retention of 11.5% after 50 cycles.