In-situ covalently bridged ceramic-polymer electrolyte with fast, durable ions conductive channels for high-safety...

To meet the requirements of high-energy-density lithium batteries, an urgent increasing demand exists for high-safety electrolyte compatibility with high-voltage cathodes. However, the safety issues of widely used ether-based liquid electrolytes and their low oxidation stability have not been effectively resolved. Herein, a covalently bridged electrolyte with ceramics as the crosslinking center is constructed in situ. The fabricated electrolyte combines the advantages of polymer (poly-1,3-dioxolane (PDOL)) and ceramic (mesoporous SiO₂ (MS)) as well as its unique crosslinking structures, possessing high oxidation stability, safety, and mechanical strength. Consequently, the symmetrical Li cells present a stable overpotential of 21 and 32 mV for up to 1000 h at 0.25 mAh cm^-2 and 3700 h at 0.5 mAh cm^-2, respectively. The assembled LiFePO₄ (LFP)/Li cell delivers a capacity retention of 87.6 % after 600 cycles at 1C and shows only a small voltage gap of approximately 0.07 V. Even at 2C, the LFP/Li cell still exhibits a low capacity decay of 0.024 % per cycle over 1000 cycles. Moreover, the LiNi_0.8Mn_0.1Co_0.1O₂ (NCM811)/Li cell maintains a high discharge capacity of 152.1 mAh/g and a capacity retention of 93.2 % after 300 cycles. Therefore, the invented electrolyte enables high-energy-density Li batteries with high safety and excellent electrochemical performance, blazing a trail for their rapid development.