Ionic Conduction in Porous Media

Abstract

Electrolytes can be contained by capillary forces within high surface area porous media. Ionic conduction within these two‐phase composites depends upon the quantity, distribution, and geometric structure of the electrolyte within the solid matrix. In this report, we examine how the variables of geometric structures can influence the conductivity of such two‐phase composites. We define geometric variables using both capillary and percolation models of random structures. We deal specifically with composites of fumed silica and molten eutectic which are used in thermal batteries. However, our treatment is general and can be applied to other systems, including solid‐state, inhomogeneous ionic, and electronic conductors.