Development of a PEO-based lithium ion conductive epoxy resin polymer electrolyte

Epoxy resins have a newly found role as polymer hosts in solid and gel polymer electrolyte systems. Originally sought for their mechanical properties, advantages also include high atom economy and minimal waste stream in their preparation. This report details solid state polymer electrolytes prepared with PEO-based epoxy resins cured with 4,4′-methylenebis(cyclohexylamine) and doped with a solution of lithium salts in PC. The resulting solid state polymer electrolyte has room temperature conductivity nearing 10−3 S cm−1 and notable mechanical strength (up to 970 kPa ultimate tensile strength and 2.6 MPa ultimate compressive strength). Chemical and thermal analyses give insight into the molecular structure and curing behavior of the solid state polymer electrolyte relative to lithium salt concentration as well as over time. The effects of salt solubility on composition and conductivity of the electrolyte are further elucidated through computational studies of ion behavior in a PEO membrane.