A high ion conductive solid electrolyte film and interface stabilization strategy for solid-state Li-S battery

Abstract

Lithium-sulfur (Li-S) batteries are regarded as a potential next-generation electrochemical energy storage technology. However, polysulfide shuttle effect and lithium dendrite growth always worsen the battery's cycling performance, especially, the safety problem of liquid electrolyte has also become a major challenge to the development and application of Li-S batteries. Herein, a high ion conductive poly(1,3-dioxolane) solid electrolyte film (PDOL) was introduced in Li-S battery, which hinders the shuttle of polysulfides, and forms a uniform LiF protective layer on the lithium metal contact surface to inhibit the growth of lithium dendrites. Meanwhile, the problem of high interfacial impedance in solid-state Li-S batteries was also solved by adding a trace amount of flexible organic ether electrolyte to the solid electrolyte/electrode interface. The assembled quasi-solid-state S/PDOL/Li cell shows low interfacial impedance less than 75 Ω and can be stably cycled over 500 times at 0.1 C. This rigid-flexible solid electrolyte design method provides a practical idea for the development of high-performance solid-state Li-S batteries.