Design Unique Air-Stable and Li-Metal Compatible Sulfide Electrolyte via Exploration of Anion Functional Units for All-Solid-State Lithium-Metal Batteries

The marriage of solid-state sulfide electrolytes (SSSEs) with Li-anode and oxide-based cathodes can multiply the energy density of all-solid-state Lithium-metal batteries (ASSLMBs). However, hydrolysis in the air, reduction at the Li/SSSE interface, and growth of Li-dendrites inside SSSEs collectively block the route of sulfide-based ASSLMBs. Herein, a novel Li2.96P0.98S3.92O0.06-Li3N glass-ceramic electrolyte (GCE) is developed, wherein O and N substitution produce POS33- and Li3N unique functional units enable superior sigma(Li+) 1.58 mS cm(-1) at RT. Notably, POS33- units in Li2.96P0.98S3.92O0.06-Li3N excellently prevent the structural degradation against moisture @45-50%. The critical current density of Li2.96P0.98S3.92O0.06-Li3N reaches 1 mA cm(-2)/1 mAh cm(-2) @ RT. Moreover, Li//Li cells realize unprecedented Li-plating/stripping >1000 h at 0.3 mA cm(-2)/0.3 mAh cm(-2) and 0.5 mA cm(-2)/0.5 mAh cm(-2) at RT. ToF-SIMS and depth-X-ray photoelectron spectroscopy (XPS) confirm the formation of Pre-solid-electrolyte interphase (SEI) enriched with thermodynamically stable Li2O and Li3N species at Li/Li2.96P0.98S3.92O0.06-Li3N interface, suppressing the interfacial reactions and growth of Li-dendrites inside Li2.96P0.98S3.92O0.06-Li3N. Furthermore, LiNbO3@NCA/Li2.96P0.98S3.92O0.06-Li3N/Li cells deliver a remarkable initial discharge capacity of 177.3, 177.6, and 177.8 mAh g(-1) with 7.50, 16.50, and 21.50 mg cm(-2) of NCA loading. Thus, the novel Li2.96P0.98S3.92O0.06-Li3N GCE addresses all key challenging issues and has tremendous potential to be used in sulfide-based high-energy ASSLMBs.