Thermal transport properties of complex salts systems in solid and liquid states for new energy sources applications

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The objective of the proposed research program is to develop a robust and systematic approach to predict the thermal transport properties of complex molten and solid salts multicomponent systems. The objective is two-fold: first, alleviate the severe lack of experimental data in order to assist the solar and nuclear industry to design optimal materials and, secondly, understand, from a microscopic point of view, the thermal transport mechanisms within complex salts in both liquid and solid states, especially involving alloying effects in solutions. Nowadays, materials science is strongly dependent on models and numerical simulations to predict the behaviour of materials in order, for instance, to optimize industrial processes and to design new materials. When one wants to predict the thermophysical, structural and thermal properties of complex materials as a function of composition, temperature and constraints, it has been shown that Density Functional Theory (DFT) and Equilibrium Molecular Dynamics (EMD) are the classes of atomistic scale simulations with the best predictive capability. If atomistic scale simulations could predict materials properties at some specific temperature and compositions and  constraints, they can not formally represent these properties in a wide range of compositions and temperatures. In order to achieve this, the physics behind the studied properties must be understood and the properties must be formulated as a function the physical parameters governing the property evolution with temperature, composition and constraints. The thermal conductivity and thermal diffusivity of molten salts are key properties to consider in the design of Phase Change Materials (PCMs) for Concentrate Solar Power (CSP) or Nuclear Molten Slats Reactor (NMSR) materials which, today, are considered as promising sources of energy to reduce our world dependence on fossil fuels energy, therefore contributing to the reduction of greenhouse gas emissions. Due to its high storage capacity, low cost and good thermal properties, LiCl-NaCl-KCl-MgCl2 (low in LiCl) is considered as a good candidate for next generations of PCM for CSP applications. However, by adding additives such as CaCl2, SrCl2 and ZnCl2 the heat storage capacity and corrosion resistance can be improved while keeping a low melting temperature.  Likewise, the understanding and the analytical formulation of the thermal transport of LiF-NaF-BeF2-UF4-ThF4-PuF3 is an important challenge in the fuel design for the next generations of NMSR. To achieve this, it is necessary to understand the relationship between the thermal transport and the local structure.  For the first time, the proposed research permits to predict accurately the thermal conductivity and diffusivity of complex materials for CSP and NMRS materials from atomistic scale simulations and theoretical modelling. Benefits to Canada will be important for research of a sustainable alternative energy sources to fossil fuels.