Electrolytic conduction in amorphous salt complexed polyethers

Phosphate ester extended and crosslinked poly(ethylene glycol)s were prepared from reaction of the glycols with chlorophosphates. Fully amorphous electrolytes formed with lithium trifluoromethanesulphonate showed enhanced conductivity over comparable poly(ethylene oxide) electrolytes in the temperature range 293–373 K. With O/Li=27.6, α=5.2×10⁻⁶S cm⁻¹ at 293 K. A conductivity maximum was detected at ca. 1 mol dm⁻³ concentration consistent with the increase in charge carrier density opposed by medium viscosity. For all complexes the temperature dependence of conductivity obeyed the Vogel-Tamman-Fulcher and Williams-Landel-Ferry equations, with T_g(onset) for the parent polymer as the ideal glass transition temperature. Activation energy parameters from use of the VTF equation and Adam-Gibbs configurational entropy model showed a linear dependence on salt concentration.