Speaker
Description
Solid-state battery (SSB) technology presents a transformative alternative to conventional liquid-state batteries, addressing many of their inherent weaknesses. However, current SSB materials are limited by poor charge-discharge rates, primarily due to restricted ion diffusion and low conductivity across buried interfaces. Conventional characterization and ion diffusion measurements focus mainly on bulk properties, are inherently destructive, or offer limited resolution to observe interfacial behavior.
In contrast, by using $\beta$-NMR at VITO, it is possible to determine the interfacial ion mobility non-destructively through low-energy ion implantations. $\mathrm{Li}^{+}$ diffusion in the bulk electrolyte and anode-electrolyte interface of commercially relevant SSBs (Li-Li$_7$PS$_6$ and Li-Li$_{5.5}$PS$_{4.5}$Cl$_{1.5}$ half-cells) was investigated by $^{8}\mathrm{Li}$ implantations at 30keV and with varying Li layer thicknesses to observe diffusion and the width of the Li-electrolyte interface. Results from $\beta$-NMR were corroborated by $\mu$SR experiments using bulk and surface muons at the S$\mu$S facility of the Paul Scherrer Institute, Switzerland.
These measurements were also part of the commissioning of a new end station at VITO with the ability to: (a) heat and cool samples, (b) insert multiple air-sensitive samples via a load-lock system, (c) accommodate new RF coils and $\beta$-detectors, (d) transport samples through the beamline using external manipulators, and (e) maintain compatibility with high vacuum and a strong magnetic field exhibiting ppm-level homogeneity.
