Molten Li Salt Solvate-Silica Nanoparticle Composite Electrolytes with Tailored Rheological Properties

Abstract

Nanocomposite electrolytes comprising molten Li salt solvates (MLSs) and inorganic fillers provide liquid-like processing and reasonably high Li ion transport properties. Thus, they can be potentially used as thermally-stable and mechanically-robust electrolytes. In this study, nanocomposite electrolytes exhibiting two distinct non-Newtonian rheological responses, i.e., shear thinning and shear thickening behaviors, were prepared using glyme-and sulfolane-based molten Li salt solvates and hydrophilic fumed silica without any surface modification of the silica. The rheological responses strongly depended on the anionic structure of the MLSs. The MLS-silica composites containing bis(trifluoromethanesulfonyl)amide (TFSA) and BF 4 anions formed a shear thinning gel and shear thickening fluid, respectively. The characteristic rheological properties (elastic modulus for the shear thinning gel and the maximum peak viscosity and critical shear rate for the shear thickening system) were extensively tailored by the silica content in addition to the chemical structure of the MLSs, while the changes in their ion transport properties were moderate even in the presence of silica fillers.

Direct Printable Proton-Conducting Nanocomposite Inks for All-Quasi-Solid-State Electrochemical Capacitors

“…10 wt %) but did not change considerably when the content was more than 12.5 wt %. This result indicates that some interactions between ionic liquid and inorganic silica exist, resulting in higher viscosity with a higher silica content, which seems to be consistent with previous reports. ,,,− This result showed that the viscosity of the 3D printable precursor mixture composed of inorganic silica, photocurable resin, and ionic liquid can be modulated, and it also suggests that the inks with an appropriate mixing ratio can be used for 3D printing.…”