Atomistic insight into the structural and thermodynamics properties of CaF2-MgF2-SiO2 fluoride system at high temperatures

Silicon is the dominant solar material because of its abundance, low cost, and high solar efficiency. But manufacturing high-purity silicon required for solar energy is very complex, hard to scale, and unsafe since it involves dealing with toxic flammable gases. Therefore, a new solar silicon production technology based on the CaF₂-MgF₂ molten fluoride electrolysis has been proposed. To comprehensively investigate the mechanism of complex cluster formation and diffusion behavior of silicon/oxygen ions at high-temperature, the Matlantis and its machine-learning Preferred Potentials are introduced in this study. The equilibrium volumes will be determined by Birch-Murnaghan equation of state (EOS) in AIMD and used for subsequent production simulations. Radial distribution function (RDF) and angular distribution function (ADF) are used for analyzing the local structure information. Thermodynamics and transport properties of molten salt electrolyte such as density, heat capacity, viscosity etc. are also examined and compared to the existed experimental results at multiple compositions and temperatures.