3D Porous Single‐Ion Conductive Polymer Electrolyte Integrated with Ether Polymer Networks for High‐Performance Lithium‐Metal Batteries

The integration of polymer‐based electrolytes into next‐generation lithium‐metal batteries (LMBs) offers significant potential for enhancing energy density and safety. However, their development is impeded by challenges such as low ionic conductivity at room temperature, anion polarization effects, and a low lithium‐ion transference number. This investigation aims to address the limitations by combining single‐ion conductive polymer (SICP) and ether polymer network (EPN) electrolytes. The interwoven structure of SICP and EPN ensures a uniform lithium‐ion distribution, facilitating efficient delocalized lithium‐ion transport. Utilizing sulfonated poly(vinylidene fluoride‐co‐hexafluoropropylene)‐based SICP with EPN enhances ionic conductivity, electrochemical stability, and mechanical strength. The optimized SICP‐EPN membrane exhibits an ionic conductivity of ≈10 −4 S cm −1 , an electrochemical stability window exceeding 4.9 V, and a lithium‐ion transport number of 0.58 at 30 °C. The Li/SICP‐EPN/NCM811 cell demonstrates an initial discharge capacity of 189 mAh g −1 and a Coulombic efficiency of 99.7% at 0.1 C at 30 °C, maintaining stability with minimal capacity fading after 250 charge–discharge cycles at 0.5 C. These findings highlight the potential of SICP for delocalized lithium‐ion transport and present a viable economic approach to enhancing the performance of polymer electrolyte‐based high‐energy‐density LMBs.