High safety and long-life lithium batteries with low leakage and high wettability ceramic-polymer electrolyte

The development of ceramic-polymer electrolyte with high mechanical and electrochemical properties is the key to address the safety issue of high-performance lithium batteries due to the use of flammable organic liquid electrolytes. In this work, we designed and synthesized a flexible low liquid leakage and high wettability ceramic-polymer electrolyte (CPE) based on poly(vinylidene fluoride) (PVDF)-poly(ethylene oxide) (PEO)-γ-Al₂O₃ membrane with excellent mechanical and thermal stability. After being wetted by a very small amount of LiPF₆-based liquid electrolyte, symmetrical Li, Li/LiFePO₄ (LFP), and LFP/Li₄Ti₅O₁₂ (LTO) cells with this PVDF/PEO-γ-Al₂O₃-LiPF₆ CPE displayed much better cycling stabilities than that of commercial Celgard 2320 separator with a sufficient amount of liquid electrolyte. The CPE requires only a small amount of liquid electrolyte to achieve the desired electrochemical performance of lithium batteries. Its low liquid leakage characteristic also enhances the safety of lithium batteries, with the potential to replace the commercial separators.