Construction of stable solid electrolyte interphase on lithium anode for long-cycling solid-state lithium–sulfur batteries

Abstract Solid polymer electrolyte (SPE)-based solid-state lithium‑sulfur (Li S) batteries have been intensely investigated as an appealing next-generation rechargeable battery technology. However, their practical application is severely impeded by their poor cycling stability and safety concerns, which are mainly caused by the poor quality of the solid electrolyte interphase (SEI) on the surface of Li metal anode. Herein, we report that phosphorus pentasulfide (P2S5) can work as a sacrificial electrolyte additive for SPE-based solid-state Li S batteries. This additive results in the formation of a compact and conductive protection layer on the surface of Li metal anode, consequently suppressing the polysulfides shuttling in the polymer matrix and the growth of Li dendrite during the cell operation. Under the optimization condition, the solid-state Li S cell exhibit a high specific capacity of 897 mAh g−1 and can charge/discharge cycle over 350 cycles with high Coulombic efficiency. This work describes an effective electrolyte additive for constructing stable SEI on the surface of Li metal anode, which allows to construct practicable and reliable solid-state Li S batteries with high energy-density and long-term cycling performance.