Sn/C composite anodes for Li-ion batteries

Composites of Sn/C were synthesized by infiltrating tetraethyltin into mechanically milled polystyrene resin powder. Heat-treatment of the precursor in Ar atmosphere at 600 degreesC results in crystalline tin and amorphous carbon. The resultant composite exhibits a capacity of 480 mAh/g with good capacity retention (0.15% loss/cycle). Transmission electron microscopy analysis indicates nanocrystalline (similar to 200 nm) spherical tin particles embedded in large carbon particles (congruent to2 to 10 mum). The embedment of nanocrystalline tin within carbon appears to be the main reason for the good cyclability suggesting the excellent potential of these Sn/C based composites for use as alternative anodes for lithium-ion batteries. (C) 2004 The Electrochemical Society.