“…This is reasonable considering that for ionic conductivity measurements an external electric eld is applied, so that primarily charged species are taken into account, whereas data from PFG-NMR reect diffusion from all lithium species present in the electrolyte, including neutral clusters or aggregates as well as motion of otherwise associated lithium ions. 66 In principle, the degree of ion association a may be determined from the ratio of the two diffusion coefficients, as reported for some liquid or polymer electrolytes suitable for lithium ion batteries, 34,65,[67][68][69][70] as dividing D Li + ,calc by D Li + ,meas yields (1 À a), the degree of Li ion dissociation (cf. Table 1).…”