Computational and Experimental Analysis of Structural and Thermophysical Properties of LiX-KX (X = Chloride, Iodide, or Bromide) Molten Salts

Molten salts containing lithium (Li) and potassium (K) halides, including chlorides (Cl), bromides (Br), and iodides (I), are pivotal in advanced technological applications, including nuclear reactors, thermal batteries, and industrial pyrochemical processes. Despite their significance, the availability of the temperature-dependent structural and thermophysical properties for these molten salts remain scarce. This study addresses this knowledge gap by predicting and measuring the key properties, such as coordination number, radial distribution function, density, specific heat capacity, and volumetric thermal expansion, of molten LiI-KI, LiBr-KBr, and LiCl-KCl eutectic mixtures. Utilizing ab initio molecular dynamics simulations, we predicted these properties for LiX-KX (X = Br, I) across various temperatures using chlorides as a benchmark. Experimental measurements using the Archimedes method and differential scanning calorimetry validated the densities, phase transitions and heat capacities of these molten salts. Our comprehensive analysis of the structural and thermophysical properties provides critical insights into the fundamental behavior of these molten salts at various temperatures, enhancing the understanding necessary for their application in advanced technologies.