An Efficient Route to Polymeric Electrolyte Membranes with Interparticle Chain Microstructure Toward High-Temperature Lithium-Ion Batteries

The application of current polymer lithium-ion batteries is still challenged with the limited electrochemical performance and thermal stability of polymeric electrolyte membranes as battery separators. In this report, an efficient route to polymeric polyvinylidene fluoride-hexafluoropropylene electrolyte membranes with interparticle chain microstructure is presented. The structure is capable of hosting sufficient electrolyte for efficient migration of electrolyte salts. The electrolyte uptake ratio is up to 188.4% and the highest ionic conductivity reaches 1.08 mS cm⁻¹ at room temperature. In particular, the membrane exhibits higher thermal resistance compared with traditional separators, only giving rise to a subtle shrinkage at 175 °C and allows for efficient battery operation for a record number of charge/discharge cycles at 110 °C. The electrolyte membrane through such a single-step method shows promising application potentials in electric vehicles and wearable electronics, especially in extreme operation conditions.