Highly conductive ionic liquid based ternary polymer electrolytes obtained by in situ photopolymerisation

New ternary polymer electrolytes based on a commercial cross-linking resin dianol diacrylate (DDA), tetramethylene sulphone (TMS) as a compatibilizing solvent and ionic liquids (ILs) were prepared by in situ photopolymerisation. The electrolytes containing two polymer-to-TMS-to-IL ratios, 20:30:50 and 20:20:60 by weight, respectively and six various ILs were investigated. The obtained materials were flexible, self-standing with good mechanical properties and a long-term stability. They showed high ionic conductivities, in the range of ca. 7 x 10(-3) to 3 x 10(-2) S cm(-1) at 25 degrees C. A very important result is that the conductivities of all the prepared polymer electrolytes exceeded the conductivities of the corresponding neat ILs by 2-3.5 times. The temperature dependence of the ionic conductivity correlates with VTF equation. All the materials prepared were characterized by a broad electrochemical stability window (3.3-3.7V). (C) 2009 Elsevier Ltd. All rights reserved.