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 di ffers from previous work by allowing for Langevin like motion rather t han instantaneous hops, by including possible carrier motion attached to moving segments, and by providing for direct relation to free-volum e theory, leading to a Vogel-Tammann-Fulcher (VTF) equation for the de conductivity. Application to the long-range component of the frequenc y-dependent conductivity shows that the statistical distribution of ca rrier probability within a confining environment is attained much more rapidly than change from one confining environment into another. Cond itions are obtained under which an increased rate of environmental reo rganization generally increases conductivity.