Temperature Dependence of Ion Injection by Metallic Electrodes into Non-Polar Dielectric Liquids

This study deals with the influence of temperature on the electrical conduction of solutions of electrolytes in n-decane. The temperature dependence of the ion mobility deduced from transit time measurements is due to the viscosity variation. The activation energy for the ion creation is rather well foreseen from the Fuoss model of dissociation of ion-pairs and from the assumption that the distance between ions in an ion-pair decreases with temperature. From the injection current density, we deduce that the charge density qA at the distance xA of closest approach from the metal follows the relation qA/qo= exp[ eo/16¿¿xLKT] whatever the liquid conductivity (a= 2Kqo) and the temperature, and is entirely determined by the interactions of an ion with its image. This observation, in agreement with our previous ones, supports the assumption of a charge-transfer step involving only the electrolyte.