Advances in the Application of Ionic Liquids in PEO-based Lithium Ion Solid-State Electrolytes: From A View of Fillers

Abstract

Poly (ethylene oxide) (PEO) composite solid-state electrolytes have been considered as promising candidate electrolytes for all-solid-state lithium batteries with high safety and excellent mechanical properties. However, the ionic conductivity of PEO-based electrolytes is usually low at room temperature, which limits their performance in practical applications. Moreover, the interfacial compatibility with high-voltage cathode materials remains a challenge despite the better compatibility with lithium metal anodes. The inevitable problem of lithium dendrite growth is also affecting the safety performance of this battery. Ionic liquids (ILs) with high conductivity and ionic mobility, enabling batteries to achieve a higher electrochemical window, offers a new platform for more environmentally friendly and sustainable all-solid-state lithium batteries. Considering that there has been a surge of exciting research activities in the field of PEO/ILs systems, this review is tended to summarize the mechanism of different kinds of ILs in PEO-based solid polymer electrolytes, and provide a comprehensive overview of the application of ILs in all-solid-state lithium batteries from a view of fillers. Ultimately, this information is expected to guide the design and optimization of novel PEO/ILs systems with enhanced properties for real-world applications.