EET Optimization Method For Li Halide Molten Salt

As a new type of electrochemical energy storage technology developed in recent years,the liquid metal battery has the advantages of low cost and long life;broad application prospects in the field of large-scale energy storage.The molten salt as an electrolyte greatly affects the working efficiency of the battery system,so the optimization of molten salt is very important for the development of liquid metal battery.Li-based liquid metal battery has received much attention due to its excellent electrochemical performance.The current research content is mainly the melting point,charge-discharge performance,and viscosity research with ration under a fixed component.Since the current research method of molten salt is molecular dynamics theory,its model is complex and with a large of calculation,so it is not easy running the whole molten salt properties systematically.Empirical electron theory of solids and molecules is a simple and universal method to study the relationship between physical properties and electron structure.This paper uses empirical electron theoretical models to systematically study elemental molten salts LiX(X=F,Cl,Br,I),binary molten salts LiF-LiCl,LiF-LiBr,LiF-LiI,LiCl-LiBr,LiCl-Lil,and the ternary molten salt LiF-LiCl-LiBr system.The valence electron structure and the thermal properties of Li molten salt has been studied,including cohesive energy,melting point,and the relationship between the properties and the valence electron structure.The calculated values are in good agreement with the experimental ones.The melting point of the same molten salt decreases as the number of the maximum covalent electron logarithms decreases;the cohesive energy increases as the number of valence electrons increases.In addition,the density and Li ion solubility are calculated according a rigid model according to the ionic size and the liquid density.The study shows that as the components of the molten salt mixture increase,the solubility of lithium ions decreases,while ensuring that the density of the multiple molten salt is within a reasonable range without destroying the stability of the three-liquid layer.According to the Frankel viscosity calculation model,the viscosity of Li-based molten salt is calculated at the melting point,which provides valuable data support for the optimization of molten salt performance.