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 degrees 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=O and C-O-C groups of TEGDA-based polymer matrix form the complex with Li+ ions. (C) 2009 Elsevier B.V. All rights reserved.