Solid polymer electrolytes. XI. Preparation, characterization and ionic conductivity of new plasticized polymer electrolytes based on chemical-covalent polyether-siloxane hybrids

A new hybrid polymer electrolyte system based on chemical-covalent polyether and siloxane phases is designed and prepared via the sol-gel approach and epoxide crosslinking. FT-IR, C-13 solid-state NMR, and thermal analysis (differential scanning calorimetry (DSC) and TGA) are used to characterize the structure of these hybrids. These hybrid films are immersed into the liquid electrolyte (1M LiClO4/propylene carbonate) to form plasticized polymer electrolytes. The effects of hybrid composition, liquid electrolyte content, and temperature on the ionic conductivity of hybrid electrolytes are investigated and discussed. DSC traces demonstrate the presence of two second-order transitions for all the samples and show a significant change in the thermal events with the amount of absorbed LiClO4/PC content. TGA results indicate these hybrid networks with excellent thermal stability. The EDS-0.5 sample with a 75 wt % liquid electrolyte exhibits the ionic conductivity of 5.3 X 10(-3) S cm(-1) at 95 degrees C and 1.4 X 10(-3) S cm(-1) at 15 degrees C, in which the film shows homogenous and good mechanical strength as well as good chemical stability. In the plot of ionic conductivity and composition for these hybrids containing 45 wt % liquid electrolyte, the conductivity shows a maximum value corresponding to the sample with the weight ratio of GPTMS/PEGDE of 0.1. These obtained results are correlated and used to interpret the ion conduction behavior within the hybrid networks. (c) 2006 Wiley Periodicals, Inc.