Transport properties of non-aqueous lithium electrolyte coexisting with porous solid materials: Montmorillonite-based electrolyte composite system

In order to discuss the hetero-phase effect of the coexisting solid phase on the ionic conduction in non-aqueous lithium electrolyte solution, the conductivity and transport number of ionic species in non-aqueous lithium perchlorate solution/montmorillonite clay composite system were measured using Hittorfʹs cell. Transport number of lithium ion rapidly increased as the clay content increased, while total conductivity gradually decreased. The calculated ionic mobility of lithium ion was constant in the liquid content range of 75–90 vol.%. The activation energy of the conductivity for both ions separately obtained from the temperature dependence of the ionic mobilities. The activation energy of lithium ion was ca. 10 kJ mol−1 and extremely lower than anion species. It is proved that the lithium ion transfer is promoted by the cation exchange materials using inorganic clay materials. It is suggested that the lithium ions can transfer through the inside of clay structure and anion transfer is hindered by the repulsion between anion species and clay skeleton structure.