Ionic Conductivities of Molten Alkali Metal Chloride Binary Systems by Equilibrium Molecular Dynamics Simulation: Composition and Temperature Dependence

Abstract

Conductivity of molten alkali metal chlorides is the foundation of molten-salt electrolysis process. In the study, equilibrium molecular dynamics was performed to investigate the ionic conductivities of the molten alkali metal chloride binary systems. The calculated values were in good agreement with the experimental results. Simple databases for conductivity have been built based on the verified algorithm. Mathematic expressions of conductivity vs. temperature & composition have also been obtained according to calculated data. Ionic conductivities of these melts exhibited positive dependences on temperature. Adding a smaller alkali metal cation into molten alkali chlorides could improve the conductive performance. With the gradual addition of LiCl, ionic conductivities of molten LiCl-NaCl, LiCl-KCl, LiCl-RbCl, and LiCl-CsCl all increased monotonously. The conductivities of molten NaCl-KCl, NaCl-RbCl, and NaCl-CsCl also increased with the continuous addition of NaCl. The improvement effects of LiCl on ionic conductivities of molten KCl, RbCl, and CsCl are more significant than those of NaCl.