Results of a spectroscopic study in the high molecular weight PEO-potassium triflate system indicates the presence of a crystalline compound with a 1:1 stoichiometry, (PEO)KCF3SO3, which has also been confirmed with X-ray diffraction and DSC studies. The presence of the compound leads to a decrease in ionic conductivity at very high salt concentrations. Ionic association of potassium triflate in glymes and glycols as a function of salt concentration was also studied using infrared spectroscopy, with particular attention to the effect of chain length and end group on the ionic association.