Complex formation and ionic conductivity of polyphosphazene solid electrolytes
Abstract The linear poly[(alkoxy)phosphazene], [NP(OC 2 H 4 OC 2 H 4 OCH 3 ) 2 ] n (MEEP), has been synthesized and investigated as a polymeric electrolyte host material. Amorphous solvent free polymersalt complexes formed with a variety of mono-, di-, and trivalent salts and exhibit high ionic conductivity. The conductivity varies with changes in the identify of the cation, the anion and the salt concentration. It also exhibits a non-Arrhenius temperature dependence. For alkali-metal salt complexes the cations and anions both contribute to the ionic conductivity. The complex (LiSO 3 CF 3 ) 0.25 ·MEEP exhibits a conductivity at room temperature which is 2.5 orders of magnitude greater that the corresponding poly(ethylene oxide) complex.