Hollow Sn-SnO2 Nanocrystal/Graphite Composites and Their Lithium Storage Properties

Abstract

Hollow spheres have been constructed by applying the Kirkendall effect to Sn nanocrystals. This not only accommodates the detrimental volume expansion but also reduces the Li+ transport distance enabling homogeneous Li-Sn alloying. Hollow Sn-SnO2 nanocrystals show a significantly enhanced cyclic performance compared to Sn nanocrystal alone due to its typical structure with hollow core. Sn-SnO2/graphite nanocomposites obtained by the chemical reduction and oxidation of Sn nano crystals onto graphite displayed very stable cyclic performance thanks to the role of graphite as an aggregation preventer as well as an electronic conductor.