IONIC TRANSPORT IN POLYMER ELECTROLYTES BASED ON RENEWING ENVIRONMENTS

A theory of ionic transport in polymer electrolytes is presented based on ionic environments reorganizing randomly into one another. This differs from previous work by allowing for Langevin like motion rather than instantaneous hops, by including possible carrier motion attached to moving segments, and by providing for direct relation to free-volume theory, leading to a Vogel-Tammann-Fulcher (VTF) equation for the de conductivity. Application to the long-range component of the frequency-dependent conductivity shows that the statistical distribution of carrier probability within a confining environment is attained much more rapidly than change from one confining environment into another. Conditions are obtained under which an increased rate of environmental reorganization generally increases conductivity.