FeOx-Coated SnO2 as an Anode Material for Lithium Ion Batteries

Nanostructured iron oxide is coated on commercial SnO2 nanoparticles via a simple solution route. The method involves the thermal decomposition of an iron carbonyl complex (Fe(CO)5) in the presence of SnO2 and a surfactant in an organic solvent. The resulting FeOx/SnO2 nanocomposite showed an enhanced performance as an anode material for lithium ion batteries. In a conventional electrolyte containing 5 wt % fluoroethylene carbonate (FEC), a composite FeOx/SnO2 (∼1:3 mol ratio) exhibited a stable capacity ∼480 mAh/g (at a rate of 400 mA/g) for up to 150 cycles compared with <130 mAh/g for bare SnO2. The enhanced cycle performance of FeOx/SnO2 is attributed to (i) the in situ formation of electronically conductive nanostructured Fe/Li2O matrix and (ii) the formation of better-preserved solid–electrolyte interface in the presence of FEC.