(Invited) The Impact of Interface Layer on Li Plating and Stripping Morphology

Abstract

Li metal is the preferred anode material for high energy Li batteries. However, a stable plating and stripping of Li metal at the anode−solid electrolyte interface (SEI) remains a significant challenge, particularly at practically feasible current densities. The formation of the SEI layer can significantly change the Li-nucleation density and growth morphology. With multiscale modeling, these factors can be investigated in more detail. Upon, lithiation, while a classical nucleation and growth model can describe the nucleation density of Li clusters and the charging rates in ultrahigh vacuum, a trace amount of reactive gas (oxygen for example) can change Li growth morphology. Reactive molecular dynamics simulations revealed that the fine balance between Li growth rate and the reaction rate of the thin lithium-oxide shell on the surface of the metallic Li can lead to Li nanowire formation. During delithiation, the accumulation of Li vacancies can lead to void generation and interface delamination. A DFT-informed kinetic Monte Carlo (KMC) model was developed to investigate the impact of the SEI layer, stack pressure, and alloying effects. The contact area is then incorporated into a 1D Newman battery model to simulate the impact of the contact area on the battery performance.