Lithium-Salt-Containing Ionic Liquid-Incorporated Li-Al-Layered Double Hydroxide-Based Solid Electrolyte with High-Performance and Safety in Solid-State Lithium Batteries

Solid-state lithium batteries are highly promising for energy storage applications because of their high energy density and good safety. Herein, a novel solid electrolyte based on ionic-liquid- impregnated Li-Al layered double hydroxides (Li-IL@Li-Al LDH) is reported. Since the Li+ ions can be inserted into the vacant octahedral sites of the Li-Al LDH and the related anions intercalated into the interlayer for the charge balance, which can facilitate the transport of Li+ ions and avoid the interference of anions, the Li-IL@Li-Al LDH solid electrolyte with the optimized Li-IL/Li-Al LDH wight ratio of 2:1 exhibits a high ionic conductivity of 1.04 X 10(-3) S. cm(-1) with a Li+ transfer number of 0.35 at 40 degrees C. Moreover, this solid electrolyte demonstrates excellent nonflammability, good lithium stability, high electrochemical stability, and low interface resistance with electrodes. The fabricated LiFePO4/Li-IL@Li-Al LDH (2.0:1)/Li battery displays outstanding cyclability and rate capability at 40 degrees C, indicating that the Li-IL@Li-Al LDH SE should have great potential for applications in the solid-state lithium batteries.