DFT study on nano structures of Sn/CNT complex for potential Li-Ion battery application

Abstract

From first principles calculations, we investigate the adsorption of a number of Sn structures (a single atom, a cluster, and an atomic wire) on the inner and outer surfaces of single-walled carbon nanotubes (CNTs); with an interest in the potential applications of these systems to Li-ion batteries. We find that Sn clusters have a much weaker interaction with the CNTs than single Sn atoms and that the interaction of Sn with the outer surface of the CNT is about 2-3 times greater than with the inner surface. The Sn atomic wire is stable inside zigzag (n, 0) CNTs, when n is greater than 10; moreover, we find that the adsorption energy reaches a maximum (-0.19 eV) at n ) 14 or 15. Our simulation results explain well experimental observations and suggest that CNT-encapsulated Sn is a potential anode material for Li-ion batteries, with the ability to withstand the huge volume changes that occur upon Sn alloying with Li. © 2009 American Chemical Society.