Tender-energy micro-XAS/μXRF of Cathode||Na3PS4 Interphases for All-Solid-State Sodium Batteries

All-solid-state sodium batteries suffer from poorly resolved interfacial reactions at layered-oxide cathode-electrolyte interfaces. We will use ID21 tender-energy micro-spectroscopy to build depth-resolved chemistry maps: 2D μXRF will locate interphases and nominate transects; μXANES/short EXAFS line scans at S and P K-edges and Mn/Fe/Co/Ni K-edges will quantify electrolyte speciation and cathode redox/coordination across polished cross-sections prepared at defined SOCs and storage histories. Experiments are ex situ/quasi-operando under vacuum-compatible sealing. Outputs include interphase thickness, gradient length scales, and along-interface heterogeneity, enabling mechanism-grounded guidance for coatings, cutoff windows, and stack-pressure strategies in durable ASSBs.