Observation of interfacial degradation of Li6PS5CI against lithium metal and LiCoO2 via In Situ electrochemical raman microscopy

Sulfide-based Li⁺ conducting solid electrolytes, such as argyrodite, Li₆PS₅Cl, for all-solid-state batteries can have comparable ionic conductivities with liquid electrolytes.  The interface between sulfide containing solid electrolytes and Li metal and Li-ion positive electrodes, however, has been found to be unstable, leading to poor cell performance and cycling.

Understanding the in situ evolution of interfacial layers between the electrolyte and both electrodes is of paramount importance for designing stable and long-life solid-state batteries.

In the paper' Observation of interfacial degradation of Li6PS5CI against Lithium metal and LiCoO2 via in situ electrochemical Raman microscopy' published in Chemistry Europe, researchers from this department, the University of Liverpool and the Faraday Institution used Raman microscopy to study the interface between Li₆PS₅CI electrolyte and metallic Li and LiCoO₂.  Under potential control, Raman microscopy identified the appearance of degradation products at the electrode/solid electrolyte surface.