Investigation of molten salt nanomaterials for solar thermal energy storage application

Using molten salts as thermal energy storage (TES) in concentrated solar power (CSP) system has several benefits. Molten salts are thermally stable up to very high temperatures (over 500 °C). This can extend the operational capability of CSP system and eventually improve the overall system efficiency. Molten salts typically have lower vapor pressure (less mechanical stress) and cheaper than conventional TES materials (mineral oil, fatty acid, etc.). However, the usage of molten salts as TES is limited due to their low thermo-physical properties (e.g., C_p is less than 2 J/g°C, k is less than 1W/mK). Nanomaterials are nanoparticle dispersions in a solid matrix or a solvent. They have been reported for their large enhancement in thermo-physical properties. It is expected that well dispersed nanoparticles can significantly enhance thermo-physical properties of molten salt materials. In this study, a molten salt nanomaterial will be synthesized by dispersing inorganic nanoparticles into a molten salt. Heat capacity measurement will be performed using a modulated differential scanning calorimeter (MDSC). Material characterization analyses will be performed using electron microscopes (SEM / TEM). The utility of the molten salt nanomateial as TES in CSP will be explored.