Methodological developments to expose and analyse buried interfaces in lithium solid-state batteries using <i>ex situ, in situ</i> and <i>operando</i> cycling

Lithium solid-state batteries (SSBs) are a promising technology for electrochemical energy storage systems. So far, the performance of SSBs mainly governed by electro-chemo-mechanical properties diverse solid/solid interfaces and their evolution upon cycling. However, as these buried in battery stack, comprehensive understanding remains challenge. Here, we thus provide some advances methodological developments ex situ , operando cycling/analysis interfaces. It is showed that noble gaz ion milling at liquid nitrogen temperature suitable reproducible method to prepare cross-section without any chemical/physical change even polymer-based SSBs. In addition, innovative cycling using Auger analysis was proposed first time on model Li/Li 6 PS 5 Cl stack. The interest this approach be able proceed dedicated cell use fully adjustable electron beam auger create surface potential difference followed lithium migration then SEI (Solid Electrolyte Interface) formation Li plating. Overall, work should greatly benefits all researchers working study batteries.