Simulation of ionic diffusion in solid polymer electrolytes with correlated chain motion

Based on the dynamic bond percolation model, we try to regenerate the non-Arrhenius temperature dependence for the ionic conductivity of the polyethylene oxide type polymer electrolytes by considering continuous, correlated motions of the host polymer matrix. To simulate the chain movements, periodic rotations of bond groups of several sizes were introduced into a two-dimensional square lattice. Although the Arrhenius temperature dependence of the rotation frequencies were assumed such that the rotation periods ∝ exp(E/kT), where E increases with the bond group size, the resulting logarithmic diffusivity plotted against reciprocal temperature produces a convex curvature—the typical feature observed by the experiments.