A Hybrid Solid-State Electrolyte with High Lithium-Ion Conductivity and Thermal Stability for Highly Stable Long-Cycle Lithium-Oxygen Batteries

Abstract

Solid-state electrolytes in lithium-oxygen batteries have garnered attention due to their high energy density and stability. Traditional electrolytes suffer from high interfacial resistance and poor ionic conductivity. We have developed a novel hybrid solid electrolyte by optimizing the ratio of inorganic to polymer electrolytes, incorporating doped and modified PVDF-HFP-SO3 as the polymer electrolyte in lithium-air batteries for the first time. The crystallinity and performance of this hybrid electrolyte improve with increasing LATP content. Notably, the HSE-SO3-3 electrolyte with 60% LATP exhibits exceptionally high conductivity (4.76 × 10−4 S∙cm−1 at room temperature) and a stability window exceeding 5 V, with stable operation in lithium symmetric cells for over 3500 h. Thermal stability tests indicate that the material does not ignite or deform under flame exposure. In quasi-solid-state lithium-oxygen batteries, using manganese dioxide as a catalyst and HSE-SO3-3 as the electrolyte, the battery demonstrates high discharge capacity, long-term cyclability, and stable charging performance at high rates. Therefore, this novel hybrid solid electrolyte shows great potential for high-voltage solid-state lithium-oxygen batteries.