Identification of new phase change materials in multicomponent systems
Phase change materials (PCMs) are one of the most promising alternatives for storage of thermal energy. However, the identification of proper candidates active in a desired temperature range is difficult to achieve without expensive and time-consuming experimental resources: ideal compositions such as eutectics or congruent melting points where latent heat can be harvested rather robustly are not promptly available in the literature beyond the classical binary phase diagrams. This is due to the multi-dimensionality of the chemical space (each element from the periodic table constitutes one dimension!) that makes exploration and prediction of ideal compositions of PCMs so difficult. As a remedy we will present a screening program that can process all thermodynamic databases compatible with the FactSage software in order to identify congruent melting points and eutectic compositions in multicomponent inorganic systems. This way, engineers have a powerful tool that enables easy identification of possible compositions beyond binary systems. In this lecture, hundreds of new phase change materials are presented as a result of applying this method to hundreds of thousands mixtures of up to 6 components of salts, salt hydrates or metallic alloys. The results cover melting temperatures within the range of -30 to 1600 °C.