Molecular dynamics simulations of lithium diffusion in silica-doped nanocrystalline v₂O₅

Molecular dynamics computer simulations are used to study lithium-ion diffusion in SiO₂ doped amorphous vanadia intergranular films (IGFs) in nanocrystalline V₂O₅ cathodes. Previous simulations showed rapid transport paths for Li intercalation from a solid electrolyte into vanadia cathodes via amorphous IGFs separating the vanadia crystals as a function of IGF thickness. However, ordering at the IGF/crystalline vanadia interface affected Li intercalation and required a minimum IGF thickness for rapid transport. The current simulations evaluate the role of Si (as SiO ₂) as an impurity in the IGF on interface ordering and Li transport. The simulations are done on the three different concentrations of Si ions in the IGF: 5, 10 and 15% in molar percentage. Results show that the presence of Si in the IGF retards the lithium-ion diffusion in IGF and hence, intercalation.