Phase-sensitivity of Li intercalation into Sn

Using density functional theory, we investigate Li intercalation into Sn and find a strong phase-sensitivity in the energy barriers. The rate determining steps of this process are bulk diffusion and surface penetration in alpha-Sn and beta-Sn, respectively. Although the energy barrier for bulk diffusion is lower in beta-Sn, the energy barrier for surface intercalation is much higher in beta-Sn than in alpha-Sn. Our calculations suggest that Li intercalation into alpha-Sn nanoparticles is kinetically more favorable than beta-Sn nanoparticles.