Preparation of a microporous gel polymer electrolyte with a novel preferential polymer dissolution process for Li-ion batteries

A special type of polyacrylonitrile (PAN)‐based microporous polymer electrolyte was prepared by the dissolution of poly(vinyl chloride) (PVC) with a novel preferential polymer dissolution process from cast polymer films containing various amounts of PAN and PVC. PVC, dissolved from a 50 : 50 (w/w) PAN/PVC blended polymer film, had a high ionic conductivity of 5.01 × 10−3 S/cm at the ambient temperature when soaked in a 1M solution of LiClO4 in ethylene carbonate and diethyl carbonate. The amorphosity, surface morphology, and thermal stability of the microporous gel polymer electrolyte were characterized by X‐ray diffraction, scanning electron microscopy, and differential scanning calorimetry studies. Chronoamperometry and linear‐sweep voltammetry studies were performed to determine the lithium transference number and stability of the microporous polymer electrolyte membrane, respectively. Finally, a Li‐ion polymer cell was assembled with the prepared microporous gel polymer electrolyte, and its compatibility with electrode materials was studied by cyclic voltammetry. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1891–1896, 2005