Fe2O3 nanowires on HOPG as precursor of new Carbon-based anode for high-capacity lithium ion batteries

Iron Oxides nanostructures are very promising systems for a new generation of anode material for Lithium-Ion batteries because of their high capacity associated to their surface area. A core-level photoemission study of Fe2O3 nanowires deposited on highly-oriented pyrolitic graphite (HOPG) under Li exposure is presented. The Fe-2p, Fe-3p, and Li-1s core- level lineshape evolution upon Li exposure in ultra-high-vacuum conditions clearly brings to light the Fe ion reduction from fully trivalent to prevalently divalent at saturation. Furthermore, the graphite substrate allows allocation of a large amount of Li ions surrounding the iron-oxide nanowires, opening a new scenario towards the use of graphene for improving the ionic charge exchange.