Recent applications of ionic liquids in quasi-solid-state lithium metal batteries

Quasi-solid-state lithium metal batteries are considered as one of the most promising energy storage devices, and the application of ionic liquids (ILs) as a new generation of functionalized electrolyte components in lithium metal batteries has become one of the research focuses. In this review, the very recent research work related to using ILs to develop quasi-solid-state electrolytes and their influences on the performances of quasi-solid-state lithium metal batteries were surveyed and summarized, suggesting that the introduction of ILs can improve the ionic conductivity, broaden the electrochemical stability window, and enhance the electrochemical stability of the selected electrolytes. Moreover, using ILs to prepare high-performance electrodes with unique microstructures and uniform distribution of fillers were also introduced. The composite quasi-solid-state electrolytes were suggested as the mainstream of electrolytes in the future due to the combination of the advantages of inorganic and polymer quasi-solid-state electrolytes, and their development challenges in high energy and high safety quasi-solid-state lithium metal batteries were also discussed.