Conduction of lithium ions in polymer-based electrolytes

Polymer electrolytes have been extensively studied due to their high safety, low cost, and ease of processing, and they have received significant attention in the development of solid-state lithium batteries with high energy density and enhanced safety. An ideal polymer-based electrolyte must exhibit a combination of properties, with fast ion conduction being particularly critical. This paper reviews the lithium-ion conduction mechanisms in solid, composite, and quasi-solid polymer electrolytes. The effects of inorganic fillers on Li⁺ conduction in composite polymer electrolytes, as well as the effects of liquid plasticizers on Li⁺ conduction in quasi-solid polymer electrolytes, are discussed. In addition, the application prospects of polymer electrolytes in high energy density, high safety solid-state lithium metal batteries are explored. Finally, the challenges and perspectives for the development of high-performance lithium batteries using polymer electrolytes are presented.