A comparative study of coordination between host polymers and Li+ ions in UV-cured gel polymer electrolytes

Abstract

Crosslinked gel polymer electrolytes are prepared via free radical photo-polymerization of 1,6-hexanediol diacrylate (HDDA) or tri(ethylene glycol) diacrylate (TEGDA) with 1 M LiClO4 dissolved in a solvent mixture of ethylene carbonate (EC) and propylene carbonate (PC). TEGDA-based gel polymer electrolytes containing a polar moiety of ethylene oxide exhibit relatively high ionic conductivities over a temperature range from - 15 to 65 °C in comparison to those based on HDDA. The coordination structure between polar moieties of a polymer backbone and Li+ ions is examined using a Fourier transform infrared (FT-IR) spectroscopy. The results of FT-IR analyses manifest that the C{double bond, long}O and C{single bond}O{single bond}C groups of TEGDA-based polymer matrix form the complex with Li+ ions.