Abstract
Concentrating solar power is a pivotal technology in global transition toward renewable energy, providing a viable pathway for dispatchable and base-load electricity generation. An important component of the concentrating solar power system is molten salts, particularly NaCl-based mixtures, which serve as both efficient heat transfer fluids and high-capacity thermal energy storage media. The influence mechanisms of micro-ionic interactions and microstructure on physicochemical properties of NaCl-based molten salt mixtures play a decisive role in exploration of more efficient molten salt formulations. We present a dataset of microstructure and physicochemical properties of NaCl-based molten salt mixtures for concentrating solar power, which involves thermal expansion coefficient, thermal conductivity, specific enthalpy of fusion, specific heat capacity, density, and viscosity of mixtures, ionic self-diffusion coefficient, coordination bond angle and coordination bond length of ion pairs, and coordination number of ions across varying elemental compositions and a wide temperature ranges from 556 K to 1400 K, which significantly exceeds the current operating limits of commercial nitrate-based solar salt. The dataset may help to integrate concentrating solar power with other renewable energy technologies, which is essential for maximizing its impact on global climate change mitigation efforts.