A pfg-NMR investigation of the diffusion coefficients of anionic species in the system PPG4000-LiCF3SO3

The present study shows that the anionic diffusion coefficient is inversely proportional to solution viscosity in the PPG4000-LiCF3SO3 electrolyte system over a large concentration range, as probed by 19F pfg-NMR spectroscopy. This is in contrast to the behavior of the equivalent ionic conductivity which generally exhibits a rapid increase with increasing concentration over the same range in PPG4000-based electrolytes. Differences are attributable to the microphase separation previously reported for these systems and to differences in the timescales probed with the difference experimental techniques.