Bulk and interface-strengthened Li7P2.9Sb0.1S10.65O0.15I0.2 electrolyte via dual-source doping for all-solid-state lithium-sulfur batteries

Abstract

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 (Sb2O3 and LiI) strategy to prepare a multifunctional sulfide solid electrolyte. Sb2O3 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.