Key parameter governing lithium ion mobility in monolayer Ionic-liquid tethered on metal oxide nanoparticles as solvent-free hybrid electrolytes.

Abstract

Here, we have synthesized and characterized a series of new hybrid materials based on ionic liquid grafted on metal oxide for designing solvent-free solid-state electrolytes. The aim of this study is to determine the key parameters affecting the ionic conduction properties of the materials. Several aspects were modulated, such as the chemical composition of the metal oxide (SiO2, ZrO2 or Al2O3), the anchoring bond (silane chemistry or coordinative bond) and the length and nature of the spacer (propyl, undecyl, polyethylene glycol). The ionic conductivity of the hybrid composite mixed with the lithium salt reach ionic conductivity of 4.10-5 S.cm-1 without any solvent or plasticizers. This study reveals that lithium mobility is affected by the molecular structure of the ionic liquid and the grafting function, but more driven by the organization of the ILs on the surface of the nanomaterial.