Synthesis and modeling of polysiloxane-based salt-in-polymer electrolytes with various additives.

The effect of both nanoparticles and low molecular weight borate esters on the ionic conductivity of cross-linked polysiloxanes was systematically investigated by means of measuring conductivity spectra in the impedance regime at temperatures between −30 and 90 °C. Salt-in-polymer electrolytes were prepared by dissolving lithium triflate (LiSO3CF3) in comblike polysiloxanes bearing one methyl and one oligoether side group per silicon. An amount of 10 mol % of the oligoether side groups exhibited a terminal allytrimethoxysilane serving as a cross-linker moiety (T0.1OPS). Thus prepared polymer electrolyte membranes were completely amorphous and mechanically stable with an optimum conductivity value of 5.7 × 10−5 S·cm−1 at 15 wt % of lithium triflate (LiSO3CF3) at room temperature (T0.1OPS + 15 wt % LiSO3CF3). Further investigations concerned the influence of additives, i.e., nanosized ceramic fillers (α-Al2O3 and SiO2, up to 10 wt %) as well as two low molecular weight borate esters (tris(2-(2-methoxyethoxy...