Bulk and interface-strengthened Li 7 P 2.9 Sb 0.1 S 10.65 O 0.15 I 0.2 electrolyte via dual-source doping for all-solid-state lithium-sulfur batteries

Sulfide solid electrolyte is a promising candidate for the development of high-energy lithium-sulfur (Li-S) batteries. However, the concurrent improvement of ionic conductivity, bulk air stability, and compatibility of the electrolyte/electrode interface of sulfide solid electrolyte remains a huge challenge. Herein, we propose a dual-source doping (Sb 2 O 3 and LiI) strategy to prepare a multifunctional sulfide solid electrolyte. Sb 2 O 3 can broaden the transmission path of lithium ions and improve the bulk stability, and LiI can inhibit the generation of lithium dendrites and reduce the electrolyte/electrode resistance. Therefore, the sulfide solid electrolyte can be strengthened in terms of its bulk and interface, thus exhibiting a high ionic conductivity of 1.69 × 10 −3 S cm −1 at 30°C, high air stability, and high electrochemical stability with lithium metal. On this basis, the as-prepared all-solid-state Li-S batteries (ASSLSBs) can exhibit a high specific discharge capacity after being cycled at 0.05 C for 100 cycles at room temperature (833 mA h g −1 ) or 60°C (949 mA h g −1 ). This work provides a rational scheme for the preparation of practical sulfide solid electrolytes and high-performance ASSLSBs.