Designing polymer electrolytes for advanced solid lithium-ion batteries: recent advances and future perspectives

Rechargeable Li metal batteries have attracted widespread attention because of their high energy density and long cycling life. However, their further development is limited by dendritic Li growth and safety issues due to the use of liquid electrolytes. Solid polymer electrolytes (SPEs) can effectively solve the above problems, but there is only limited success in improving the various physical and chemical properties of SPEs, especially in decoupling ionic conductivity and mechanical strength, posing great obstacles to further promoting their further studies. In this review, we firstly introduced the typical mechanism of Li+ transport in SPEs and the dendritic Li inhibition mechanism. Furthermore, we outlined existing cases related to this field, hoping to provide a comprehensive understanding and strategic guidance for designing advanced SPEs. Challenges and opportunities regarding this burgeoning field are also critically evaluated at the end.