Mesoporous soft solid electrolyte-based quaternary ammonium salt

A novel mesoporous soft solid electrolyte was successfully prepared from tetrabutylammonium hexafluorophosphate, propylene carbonate, and 200-300 nm fumed silica. The electrolyte had the highest conductivity of 5.63 mS cm(-1) at 24.9 A degrees C. Fumed silica formed a three-dimensional network through hydrogen bonds between silica particles and solvent resulting in a mesoporous channel-like structure observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The pore size distribution was ranging from 20 to 300 nm with an average pore size of 280 nm characterized by N-2 adsorption-desorption isotherm from a surface area and pore size analyzer. Analysis using cyclic voltammograms showed that the mesoporous structures allowed electrolyte ions and redox probe, namely ferrocene to move effectively in the soft solid electrolyte. We found that ferrocene and ferrocenium redox probes had diffusion coefficient values of 1.05 x 10(-6) and 1.09 x 10(-6) cm(2) s(-1), respectively. The properties of the mesoporous soft solid electrolyte-based large quaternary ammonium cation showed to be a good candidate for electrochemical applications.