Ion conductivity of comb polysiloxane polyelectrolytes containing oligoether and perfluoroether sidechains

The ion conductivity has been studied in comb polyelectrolytes consisting of a polysiloxane backbone with oligoether and lithium-sulfonate terminating perfluoroether sidechains. The room-temperature conductivity was found to reach a maximum of 2.5 x 10(-6) S/cm at 33 etheric oxygens per lithium ion. The cation mobility is coupled to the polymer segmental motion and is described by the Vogel-Tamman-Fulcher (VTF) equation. The mechanisms behind ion mobility are studied by means of the VTF parameters sigma(0), B, and T-0. In particular, the number of charge carriers as reflected in the parameter sigma(0) is shown to strongly correlate with the conductivity maxima as a function of lithium ion concentration. (C) 2003 The Electrochemical Society.