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

¹ Universite de Pau et des Pays de l’Adour, E2S UPPA, CNRS, IPREM, Pau, France
² Réseau sur le Stockage Electrochimique de l’Energie, CNRS FR3459, Amiens, France
³ Ecole Centrale Casablanca, Centre de Recherche Systèmes Complexes et Interactions, Bouskoura (Maroc)

^* Corresponding author: julien.morey@univ-pau.fr, lenaic.madec@univ-pau.fr, herve.martinez@univ-pau.fr

Published online: 2 December 2022

Abstract

Lithium solid-state batteries (SSBs) are a promising technology for electrochemical energy storage systems. So far, the performance of SSBs are mainly governed by the electro-chemo-mechanical properties of the diverse solid/solid interfaces and their evolution upon cycling. However, as these interfaces are buried in the battery stack, their comprehensive understanding remains a challenge. Here, we thus provide some advances in methodological developments for ex situ, in situ and operando cycling/analysis of these buried interfaces. It is showed that noble gaz ion milling at liquid nitrogen temperature is a suitable and reproducible method to prepare cross-section without any chemical/physical change even for polymer-based SSBs. In addition, innovative operando cycling using Auger analysis was proposed for the first time on a model Li/Li₆PS₅Cl stack. The interest of this approach is to be able to proceed without a dedicated electrochemical cell and to use the fully adjustable electron beam of the auger to create a surface potential difference followed by lithium migration then SEI (Solid Electrolyte Interface) formation and Li plating. Overall, this work should greatly benefits to all researchers working on buried interfaces study in lithium solid-state batteries.