Rheological and Interfacial Properties of Colloidal Electrolytes

Electric conductivity and rheological responses of colloidal electrolytes consisting of lithium bis(trifluoromethanesulfon) imide, polyethylene glycol (PEG) oligomer, and fumed silica have been investigated. Incorporating silica could improve ionic conductivity of the electrolytes at the same lithium/oxygen ratios. The colloidal electrolytes demonstrate a sol to gel transition with increasing silica content while they exhibit shear thickening behaviors during steady flow at intermediate range of strain rate. The presence of lithium salt, on the one hand, could lower the crystallinity of PEG or forbid the crystallization and on the other hand, interferes the chain adsorption on the surface of silica. Furthermore, lithium salt strongly retards the segmental relaxation of PEG in the colloidal electrolytes.