FeO_<i>x</i>‑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 FeO_<i>x</i>/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 FeO_<i>x</i>/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 FeO_<i>x</i>/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