Multiscale Modeling of Solid Electrolyte Interphase Formation on Oxygen-Functionalized Graphite Anodes for Lithium-Ion Batteries

The solid electrolyte interphase (SEI) plays a crucial
regulatory
role in the electrochemical reversibility of lithium-ion batteries,
yet understanding of its formation mechanism remains limited due to
compositional complexity. By integrating a multiscale simulation framework
combining density functional theory (DFT), molecular dynamics (MD)
and the REACTER protocol, which dynamically updates molecular topologies
to simulate bond-breaking and formation in fixed-valence force fields,
enhanced with topology-mapped reaction templates and physics-informed
constraints, we elucidate the atomistic mechanisms governing the initial
formation of the SEI on pristine and functionalized graphite anodes
(O-terminated, OH-terminated, and O/OH-terminated). Simulation results
reveal that functionalized graphite surfaces universally exhibit three-stage
SEI growth kinetics: rapid initial formation, transition regulation,
and steady-state growth phases. A key finding reveals that OH-terminated
surfaces accelerate the formation of thin but densely structured inorganic/organic
composite SEI layers, which effectively suppress component dissolution
into the electrolyte. This optimized interface exhibits superior transport
properties within the interfacial region between the SEI and the electrolyte,
demonstrating enhanced ionic conductivity and favorable viscosity
characteristics. Our multiscale analysis highlights electrode surface
functionalization as a highly promising strategy for controlling SEI
growth mechanisms, providing fundamental principles for the rational
design of high-performance battery interfaces.