Monte Carlo calculations were performed to simulate ion diffusion through polymer matrices. The parameters can be chosen so that a broad range of polymer electrolytes can be modeled. The focus of the present study is optimizing conductivity in polyelectrolytes. A dynamic bond percolation model was extended to include local harmonic motion of covalently bound anions in polyelectrolyte systems. Local motion of these anions facilitates cation escape from potential wells, and thus, improves overall conductivity, while maintaining a cation transference number of one. Simulations show that ion correlation has a significant effect on diffusion. Increasing the temperature or the dielectric constant of the medium reduces the dependence on ion interaction, while increasing the density of ions in the polymer matrix increases the dependence. At high densities, physical blocking significantly interferes with diffusion at all temperatures. The cation conductivity was found to maximize at a lower density in polyelectrolytes than in polymer-salt complexes.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Renewable Energy, Sustainability and the Environment
- Surfaces, Coatings and Films
- Materials Chemistry