Pressure-dependent mechanochemistry at lithium–sulfide interfaces

Characterize how pressure magnitude and loading geometry affect the coupled chemical and morphological processes at lithium metal–lithium argyrodite Li6PS5Cl interfaces, including local coordination, atomic mobility, charge redistribution, electrolyte reduction, interphase formation, and structural rearrangement.

Background

The paper studies the chemically reactive interface between lithium metal and the sulfide solid electrolyte Li6PS5Cl (LPSC), where electrolyte reduction produces an interphase containing lithium sulfide, phosphide, chloride, and mixed decomposition products. External pressure is typically applied to improve physical contact and densify solid-state battery components, but compression can also modify the local coordination, atomic mobility, charge redistribution, and structural rearrangements involved in electrolyte reduction.

Although the paper uses pressure-aware, charge-resolved machine-learning molecular dynamics to investigate pressure magnitude, loading geometry, void location, and dead-lithium evolution, the authors identify the broader pressure-dependent coupling between interfacial chemistry and morphology as insufficiently understood. Resolving this relationship is important for interpreting pressure effects and designing mechanically and chemically stable lithium–sulfide solid-state battery interfaces.