  Ion conducting polymers have a biphasic character with crystalline as well as
amorphous phases. There is moreover, a dynamic disorder due to motion of
polymer chain segments. The PEO-NH$_4$ClO$_4$ system undergoes a crossover from
a DLA-type morphology for low salt fraction (X) to a structure with polygonal
spherulites. In the present communication we show that the low X regime
exhibits a variation of diffusivity with crystallinity typical of a quenched
system, whereas the high X regime has dynamic disorder with rapid
rearrangement.
