Tailoring Topology of Terpolymers via In Situ Programmed Click Chemistry for Stable Polymer Electrolytes

ABSTRACT Polymer electrolytes (PEs), valued for their superior safety and processability in lithium metal batteries (LMBs), often face trade‐offs between ionic conductivity and mechanical strength, along with interfacial instability. Herein, we report a molecular programming strategy that encodes desired functionalities directly into the PEs network. This strategy is executed by programming urethane groups as functional units into the network via an in situ programmed click reaction, wherein trace water and Lewis acid salts in the electrolyte mediate the click crosslinking of glycidyl methacrylate with 2‐isocyanatoethyl methacrylate. In this programming, each urethane group concurrently serves as a covalent crosslinker for mechanical integrity and a dynamic unit for self‐healing, thereby constructing a topological terpolymer framework. Additionally, these units participate in reshaping the ion transport environment, guiding the formation of a mechanochemically stable interphase layer. Consequently, this programmed electrolyte exhibits a surface Young's modulus as high as 3.7 GPa, and excellent ionic conductivity. The 1 Ah pouch cell retains 96.39% capacity after 500 cycles. This work establishes a programming paradigm for PEs, advancing the application of high‐performance PEs in LMBs.