Solid polymer electrolytes from lithium (perfluorovinylether) sulfonate—Derived salts dissolved in high-molecular-weight poly(ethylene oxide)

Abstract Solid polymer electrolytes (SPEs) were prepared using new lithium salts derived from a lithium (perfluorovinylether)sulfonate (CF 2 CFOCF 2 CF 2 SO 3 Li) coupled to either a partially fluorinated alcohol (monolithium series) or a partially fluorinated diol (dilithium series). High-molecular-weight poly(ethylene oxide) (PEO) was used as the polymeric host. SPE characterization was accomplished using modulated differential scanning calorimetry (MDSC), 1 H and 19 F NMR spectroscopy and electrochemical impedance spectroscopy (EIS). Ionic conductivities for SPEs made using the new salts, and also using lithium triflate (LiTf) and lithium bis[(trifluoromethyl)sulfonyl]imide (LiTFSI) as controls, were measured over a temperature range between 120 °C and room temperature for materials with an ethylene oxide to lithium (EO/Li) ratio of 30–1. Conductivities varied depending upon the structure of the alcohol or diol used to make the salt, and were generally higher for alcohols/diols having more perfluorinated methylene groups.