Modeling metal oxide atomic layer deposition films for lithium metal anodes

Improving the stability and coulombic efficiency of lithium metal batteries requires control over the solid electrolyte interphase (SEI) composition. Electrolytes containing fluorinated anions or organic additives are known to form highly stable SEIs, but their high cost and environmental impact motivate alternative approaches to control SEI composition. Experiments show some metal oxide atomic layer deposition (ALD) anode coatings enrich fluorinated species in the SEI and promote more uniform lithium deposition, potentially reducing the need for expensive fluorinated additives. However, the molecular level mechanisms governing these effects remain poorly understood. In this work, we investigate the relationship between interfacial solvation structure and SEI formation in organic electrolyte systems with metal oxide ALD coatings, Al₂O₃ and LiAlO₂ using all-atom classical molecular dynamics simulations. We develop and validate force field parameters for LiAlO₂ capable of accurately reproducing experimental structural properties, including bond lengths, bond angles, and density. These simulations establish a foundation for future interfacial studies with LiAlO₂ and offer molecular-level insight into how interfacial solvation influences SEI composition.