Temperature-Tailored Molten Salts for Sustainable Energy Storage

The power generation sector is moving towards more renewable energy sources to reduce CO2 emissions by employing technologies such as concentrated solar power plants and liquid air energy storage systems. This work was focused on the identification of new molten salt mixtures to act as both the thermal energy store and the heat transfer fluid in such applications. Firstly, a selection process utilizing literature data and the Aspen+ property package led to the identification of five nitrate-based mixtures offering suitable trade-offs between melting point temperatures and volumetric heat capacities. Secondly, new salt compositions with improved volumetric heat capacities were created from the starting-point of commercial molten salt mixtures, and then experimentally tested to evaluate the melting points. Finally, volumetric heat capacity maps were created for the different temperature regimes, indicating three new temperature-tailored molten salt mixtures, which use the same pure constituents as that of CaLiNaK and Quaternary.