Evaluation of chemical stability of conducting ceramics to protect metallic lithium in Li/S batteries

Abstract Among the different cutting-edge solutions currently under investigation, lithium metal technologies have received a renewed interest. Thorough research work is currently carried out to enhance the safety and cyclability of the lithium metal electrode, targeting high energy post-Li-ion systems such as the lithium/sulfur technology. This study aims at investigating different inorganic protective layers that could be placed at the surface of the lithium metal electrode in a lithium/sulfur system, in order to prevent the detrimental interactions with polysulfide species and electrolyte components. The chemical stability of the selected inorganic materials (amorphous thin films, crystalline ceramics and glass-ceramics) towards ether-based (polysulfides-containing) electrolytes was studied. Although being crucial for long term cycling of Li/S cells, this issue has not been addressed so far. The chemical composition and morphology of the different materials after immersion in different electrolytes were characterized by X-ray diffraction, XPS and SEM, and the most promising materials were evaluated in Li/S cells.