The effect of salt concentration on the properties of poly[oxymethylene-oligo (oxyethylene)]/LiClO4 polymer electrolytes
Abstract The thermal and electrochemical properties of mixtures of poly[oxymethylene-oligo(oxyethylene)] (oxymethylene-linked PEG400) with lithium perchlorate were investigated. The mixtures were essentially non-crystalline at room temperature. Glass transition temperatures were found to increase as the salt concentration was increased, with a linear dependence of 1/ T g on c . Maximum conductivity at room temperature was 6×10 −5 S cm −1 at a salt concentration of 0.7-1.0 mol kg −1 (O/Li=20−30). The molar conductivity at a given temperature went through a maximum at about 0.5 mol kg −1 , but compensation for the effect of local viscosity, based on the WLF-VTF approach, showed that the “iso-viscous” molar conductivity was almost independent of salt concentration.