Novel Single Lithium‐Ion Conducting Polymer Electrolyte Based on Poly(hexafluorobutyl methacrylate–co–lithium allyl sulfonate) for Lithium‐Ion Batteries

A new type of single‐ion conducting polymer electrolyte for lithium‐ion batteries, poly(hexafluorobutyl methacrylate‐co‐lithium allyl sulfonate) (P (HFMA‐co‐ASLi)), was firstly prepared by copolymerizing hexafluorobutyl methacrylate (HFMA) and sodium allyl sulfonate (SAS) with a subsequent lithiation process. The prepared polymer electrolyte exhibits high lithium ionic conductivity (10−4 S cm−1 at 80 °C) and excellent cycle performance at high temperature, which could be attributed to the good thermal stability (remains stable up to 300 °C), mechanical properties (7.1 MPa for breaking strength) and high lithium‐ion transference number (0.92). The electrolyte also displays good electrochemical stability (4.6 V). Our obtained results prove that the polymer P (HFMA‐co‐ASLi) is a promising candidate electrolyte for lithium‐ion batteries. Full cycle: A new single‐ion conducting polymer electrolyte for lithium‐ion batteries was prepared. The lithium allyl sulfonate segments in the electrolyte provide a transferable lithium‐ion source and the Lewis base groups in the flexible side chain of hexafluorobutyl methacrylate segments facilitate solvation and desolvation. The single lithium‐ion copolymer electrolyte exhibits good cycling performance.