InF3 initiated ionic/electronic conductive SEI for highly stable solid-state lithium sulfur batteries

Lithium‑sulfur batteries, known for their high theoretical energy density, cost-effectiveness, and environmental friendliness, stand out as one of the most promising technologies in advanced secondary batteries. Nevertheless, they are facing challenges like polysulfide shuttling and the growth of lithium dendrites. In this study, we present the utilization of a bifunctional initiator, InF3, incorporated into DOL-based electrolytes for in-situ polymerization to mitigate polysulfide shuttling. Simultaneously, it promotes the development of a solid electrolyte interface (SEI) enriched with LiF and LiIn alloy on the lithium metal surface. The assembled Li|Li symmetric cells exhibit a high critical current density of 3.0 mA cm−2, together with durable cycling performance over 4000 h at a current density of 0.5 mA cm−2. Most importantly, benefiting from the effective blocking effect of PDOL-based polymer electrolytes and the robustness of the formed e−/Li+ dual conductive SEI layer, the solid-state lithium‑sulfur batteries demonstrate excellent electrochemical performance, with a high retention capacity of 774.3 mA h g−1 after 200 cycles at a 0.2 C rate, showcasing significant potential for practical applications in high-energy-density solid-state batteries.