Self-Adaptive Poly(Vinylene Carbonate) Based Electrolytes for Zero-Pressure and High-Temperature Solid-State Lithium Metal Batteries

Solid polymer electrolytes (SPEs) have attracted significant attention in next-generation solid-state batteries (SSBs). However, SPEs-based SSBs suffer from performance fading and safety concerns at high temperatures caused by the thermal instability and degradation of their electrode/electrolyte interfaces. Herein, a poly(vinylene carbonate-co-methyl acrylate)-based solid polymer electrolyte (PVC-MA-SPE) with a highly self-adaptive structure is designed. The resulting PVC-MA-SPE exhibits an ionic conductivity of 4.93 × 10 −4 S cm −1 at 120 °C and high adhesion to electrodes. At zero pressure, solid-state Li|PVC-MA-SPE|LFP batteries maintain 152.6 mAh g −1 discharge capacity and 95.4% capacity retention after 150 cycles at 1C and 120 °C. The mechanism for the improved performance is attributed to the strong intermolecular interaction of the poly(vinylene carbonate-co-methyl acrylate) (PVC-MA) network with volatile molecules. Importantly, the PVC-MA network not only enables the SPE to tightly contact with electrodes, but also contributes to forming thermally stable SEI/CEI enriched in flexible polymeric components and LiF. These properties result in enhanced interfacial stability at high temperature. This work presents a novel approach to enhance the intrinsic safety of solid-state batteries at high temperatures.