Electric-field-enhanced ionic diffusivity in electrolytes: A model study

Abstract

The time-dependent redistribution of mobile A (z+) cations and X (z-) anions in a AX solid electrolyte was calculated by solving the drift-diffusion equation. In this calculation, no first-order approximation was employed because a breakdown of the first-order approximation (FOA) probably takes place when the gradient of the chemical and/or the electrostatic potential in the electrolyte is high. Moreover, the differential diffusivity and mobility of the ions were evaluated in the electrolyte under various conditions. The calculated results were compared with those of FOA-based calculations.