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

Changchun Ai , Yilei Shu , Ziheng Zhao , Huijuan Guo , Shangqing Chen , Qun Yi

2025 Journal of Materials Chemistry A

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.

聚环氧乙烷（PEO）复合固态电解质因其高安全性和优异的机械性能，被认为是全固态锂离子电池的理想候选电解质。然而，基于PEO的电解质在室温下的离子电导率通常较低，这限制了其在实际应用中的性能。此外，尽管其与锂金属负极具有较好的兼容性，但与高压正极材料的界面兼容性仍然是一个挑战。锂枝晶生长这一不可避免的问题也影响着该类电池的安全性能。离子液体（ILs）因其高电导率和离子迁移率，能够使电池实现更高的电化学窗口，为更环保、可持续的全固态锂离子电池提供了新的平台。鉴于近年来在PEO/ILs体系领域涌现了大量令人兴奋的研究进展，本综述旨在总结不同种类离子液体在PEO基固体聚合物电解质中的作用机制，并从填料的角度全面概述离子液体在全固态锂离子电池中的应用。最终，这些信息有望为设计和优化具有增强性能的新型PEO/ILs体系提供指导，以满足实际应用需求。