SEI Formation in Sulfide-Based Solid-State Batteries: Influence of Contact Conditions on Impedance-Derived Interphase Growth Kinetics

saturation of SEI growth may originate from the presence of native surface passivation layers on lithium metal foil. Crucially, we highlight important uncertainties in experimental impedance data analysis and contextualize our findings by comparison with coulometric titration time analysis (CTTA). Overall, our findings contribute to the in-depth understanding of interphase growth kinetics in solid-state batteries and their quantification using impedance spectroscopy.