Intercalation of Lithium into Graphite: Unraveling Interfacial Effects Using First Principles Molecular Dynamics*

Understanding Li⁺ transfer at graphite-electrolyte interfaces is key to the development of next-generation lithium ion batteries. In this work, we use first principles molecular dynamics simulations to probe the relationship between the Li⁺ kinetics and interfacial chemical composition, and we elucidate the key factors that determine the ion transport. By taking into account the effects of electrolyte and variations in interfacial chemistry, we show that interfacial polarization plays a central role in the kinetics of ion transfer. Furthermore, we find that variations in the graphite surface chemical composition influence the ion desolvation process, which in turn affects interfacial ion transport, although this effect is less pronounced. Our study provides insights into the coupling of electronic and ionic effects of interfacial chemistry on ion transport, which has broad implications in optimizing electrode-electrolyte interfaces for further improvement of ion batteries.