High Capacity and Superior Cyclic Performances of All-Solid-State Lithium-Sulfur Batteries Enabled by a...

All-solid-state lithium-sulfur batteries (ASSLSBs) employing sulfide-based solid electrolytes have gained widespread attention for their high energy density and intrinsic safety. Li₁₀SnP₂S₁₂ is identified as one of the most rivaling candidates in sulfide electrolytes. Herein, a highly Li-ion-conductive Li₁₀SnP₂S₁₂ solid-state electrolyte (SSE) is synthesized via a combination of high-energy ball-milling and heat treatment processes, which is more facile and efficient compared with other previously reported methods. The obtained Li₁₀SnP₂S₁₂ SSE exhibits high ionic conductivity (3.2 × 10^-3 S cm^-1) at room temperature (RT). The effects of the annealing temperature on the Li-ion conductivity and activation energy of Li₁₀SnP₂S₁₂ are also thoroughly studied. Moreover, the ASSLSBs based on the Li₁₀SnP₂S₁₂ electrolyte are constructed, and they deliver a high initial capacity of 1601.7 mAh g^-1 at 40 mA g^-1. A favorable capacity retention upon cycling and a good rate performance are also achieved at RT. Concomitantly, the Coulombic efficiency approaches 100% during the prolonged cycling. This work tremendously accelerates the practical applications of the Li₁₀SnP₂S₁₂ SSE among the emerging high-energy ASSLSBs.