Plasticiser interactions with polymer and salt in PVC–LiCF3SO3–DMF electrolytes

The IR spectra of pure DMF, LiCF3SO3, PVC, PVC–LiCF3SO3, LiCF3SO3–DMF, PVC–DMF and PVC–LiCF3SO3–DMF have been studied as part of a systematic research on the interactions between the components of the PVC-based electrolytes. It has been found that Li+ ions interact with the chlorine atoms of PVC in PVC–LiCF3SO3 samples. In LiCF3SO3–DMF samples interactions between Li+ is observed to be with both the oxygen and nitrogen atoms of DMF. PVC–DMF interactions are evident from the disappearance of the C–Cl stretching vibrations and the shifts in some peaks attributed to DMF. Free ions and ion pairs are observed to be present in the PVC–LiCF3SO3–DMF samples which affect the ionic conductivity of the samples.