Conductance Behavior of Polymeric Ion-gel Containing Magnesium Salt

The ionic conductance behavior of a polymeric gel electrolyte system based on an ionic liquid dissolving magnesium salt has been investigated. The ion gel was composed of poly(ethylene oxide)-modified polymethacrylate (PEO-PMA) swollen with 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMITFSI) dissolving Mg[(CF3SO2)2N]2 as the second salt. The ionic conductivity varied with the gel composition. The highest conductivity, 8.8 × 10−4 S cm−1 at 20°C, was obtained for the system containing 80 wt% of the liquid component consisting of 20 mol% of the magnesium salt and 80 mol% of the ionic liquid. Raman spectra of the polymeric ion-gel revealed that the ethylene oxide units in the polymer matrix assist to dissociate the magnesium salt in the polymeric gel, which would enable the magnesium species to conduct even in the solid state at room temperature.