Regulating Micro‐phase Structure in Plastic Crystal Gel Polymer Electrolyte for Quasi‐Solid‐State Lithium Metal Batteries

Abstract Quasi‐solid‐state lithium metal batteries (QSSLMBs) necessitate stable electro‐electrolyte interfaces to ensure reliable stationary power supply, thereby placing significant emphasis on the development of polymer electrolytes with high and uniform conductivity. However, while preparing the polymer electrolytes, the uncontrolled radical polymerization process of polymer electrolytes often leads to localized phase agglomeration, resulting in inhomogeneous physiochemical properties. In this study, a method is proposed to regulate the micro‐phase structure, aiming to substantially enhance the homogeneity of physiochemical properties, specifically the ionic conductivity, through the optimization of organic monomer polymerization behavior. This proposed polymer electrolyte determines enhanced reaction kinetics and reactivity at the interfaces, thereby effectively regulating the Li plating/stripping behavior and mitigating dendrite formation. The Li||Li symmetrical cell employing the proposed polymer electrolyte demonstrates exceptional cyclic durability, surpassing 1000 h at 0.2 mA cm −2 . Additionally, the QSSLMBs employing high‐voltage LiCoO 2 as the cathode exhibit remarkable improvements in electrochemical performance, particularly in terms of cycling stability. The insights derived from this research suggest that the regulation of micro‐phase structure in polymer electrolytes represents a promising strategy to enhance the practicability of QSSLMBs.