Silicon-Containing Carbonates—Synthesis, Characterization, and Additive Effects for Silicon-Based Polymer Electrolytes

New silane and siloxane compounds containing cyclic carbonate functional groups were synthesized and characterized. The compounds were prepared via two routes: hydrosilation of SiH containing siloxanes and alcoholysis of chlorosilanes with hydroxy-terminated oligoethers. The products were purified by distillation and solvent extraction and characterized using 1H, 13C, and 29Si NMR. Upon doping with lithium bis(oxolato)borate (LiBOB), the conductivities of the compounds were determined. These carbonate compounds themselves did not show promising conductivities. However, when used as additives to silicone-containing oligoether electrolytes, the conductivities of the resulting mixtures were increased by up to 35%.