A Review of Polymer‐based Solid‐State Electrolytes for Lithium‐Metal Batteries: Structure, Kinetic, Interface Stability, and Application

Abstract Solid‐state polymer electrolytes (SPEs) for all‐solid‐state batteries (ASSBs) have received considerable attention owing to excellent processability, good flexibility, high safety levels, and superior thermal stability. However, the practical application of SPEs is currently restricted by their low ionic conductivity, narrow electrochemical oxidation window, and poor long‐term stability of lithium (Li) metal. These challenges are mainly related to the polymer molecular structures, the dynamic of the polymer electrolyte, and the polymer compound stability at the electrode‐electrolyte interface. In this review, we provide recent strategies and discuss strategies of interest for applications to high‐energy‐density ASSB, particularly the molecular design, ion‐transport dynamic mechanisms of solid polymer electrolytes, and organic‐inorganic composite. Based on recent work, perspectives on future research directions are discussed for developing solid polymer electrolytes.