Computer simulations were used to study lithium-ion diffusion in SiO2-doped amorphous vanadia intergranular films in nanocrystalline V2O5 cathodes. Previous simulations had revealed rapid transport paths for Li intercalation from a solid electrolyte into vanadia cathodes via amorphous intergranular films, separating the vanadia crystals, as a function of intergranular film thickness. However, ordering at the film/crystalline-vanadia interface affected Li intercalation and required a minimum intergranular film thickness for rapid transport. The present simulations evaluated the role of Si (as SiO2), as an impurity in the intergranular film, with regard to interface ordering and Li transport. Simulations were performed for three concentrations (5, 10 and 15mol%) of Si ions in the of intergranular film. The results showed that the presence of Si in the intergranular film retarded lithium-ion diffusion in the film, and hence intercalation.

Molecular Dynamics Simulations of Lithium Diffusion in Silica-Doped Nanocrystalline V2O5. Li, W., Garofalini, S.H.: Journal of the Electrochemical Society, 2005, 152[9], A1860-3