(a) Grain size, Lr, expressed as a number of lamellae per grain, is plotted as a function of salt concentration, r. Grain size decreases as salt concentration increases, in SEO/LiTFSI of two different molecular weights. (b) Conductivity of SEO/LiTFSI normalized by the conductivity and volume fraction of PEO/LiTFSI, σn, is plotted as a function of Lr. The marker shows the concomitant changes in r. Larger markers represent higher values of r. Normalized conductivity decreases as grain size increases.