Investigation of ion-conducting ormolytes : structure-property relationships

Abstract

Hybrid organic-inorganic composites with ionic properties, so called ormolytes (organically modified electrolytes) have been prepared by the sol-gel process from mixtures of tetraethoxysilane, tetraethylene glycol, and lithium salt. They show ionic conductivity up to 5 x 10-5 Ω-1 cm-1, with activation energies around 0.6 eV. Their properties have been related to their structure using a multitechnique approach (IR, DSC, NMR, SAXS). These materials can be described as diphasic systems with silica clusters providing the mechanical properties and the organic phase allowing the dissolution of large quantities of salts. Optical transparency and mechanical stability can be explained by the interpenetration of these two phases at a molecular level.