Synthesis of LiCH(SO2CF3)(2) and ionic conductivity of polyether salt complexes

LiCH(SO2CF3)(2) is prepared by reaction of CH2(CF3SO2)(2) with Li2CO3 and the product identity confirmed by nuclear magnetic resonance, infrared, and elemental analysis. Differential scanning calorimetry/thermogravometric analysis data indicate a decomposition temperature near 280 degrees C under N-2. PEO(x)LiCH(SO2CF3)(2) complexes show ionic conductivities as high, or higher than, those derived from other plasticizing salts, with sigma near 10(-4) (Omega cm)(-1) at 30 degrees C and 10(-3) (Omega cm)(-1) at 80 degrees C for the x = 16 complex. Differential scanning calorimetry data indicate that the polymer-salt complexes exhibit reduced crystallinity at ambient temperature and show minor crystalline phases at higher salt concentrations. Glass transition temperatures increase with salt content for the complexes. Cyclic voltammetry shows an electrolyte stability window of approximately 4.5 V.