An Overview of the Molten Salt Nanofluids as Thermal Energy Storage Media

Abstract

The research in the field of the nanofluids has experienced noticeable advances since its discovery two decades ago. These thermal fluids having minimal quantities of nano-scaled solid particles in suspension have great potential for thermal management purposes because of their superior thermophysical properties. The conventional water-based nanofluids have been extensively investigated so far with emphasis in their improved thermal conductivity. A novel class of nanofluids based on inorganic salts has been developed in the last few years with the goal of storing and transferring thermal energy under high temperatures. These molten salt-based nanofluids can in general be recognized by an enhanced specific heat due to the inclusion of the nanoparticles. However, it should be emphasized that this does not always happen since this thermophysical property depends on so many factors, including the nature of the molten salts, different preparation methods, and formation of the compressed layer and secondary nanostructures, among others, which will be thoroughly discussed in this work. This peculiar performance has caused a widespread open debate within the research community, which is currently trying to deal with the inconsistent and controversial findings, as well as attempting to overcome the lack of accurate theories and prediction models for the nanofluids in general. This review intends to present an extensive survey of the published scientific articles on the molten salt nanofluids. Other important realities concerning the development and thermal behavior of the molten salt nanofluids, such as the stability over time of the nanoparticles dispersed in the molten salts, latent heat, viscosity, and thermal conductivity, will be reviewed in the current work. Additionally, special focus will be given to concentrated solar power technology applications. Finally, the limitations and prospects of the molten salts nanofluids will be addressed and the main concluding remarks will be listed.

Synthesis and Characterization of Advanced Inorganic Nanomaterials for Energy Storage Devices

“…The integration of advanced inorganic nanomaterials into energy storage devices holds transformative potential across a myriad of applications, ranging from portable electronics to electric vehicles and grid-scale energy storage. Lithium-ion batteries, the cornerstone of portable electronics and electric vehicles, stand to benefit from the enhanced energy density, cycling stability, and safety conferred by nanoscale electrode materials [6]. Metal oxide and sulfide nanostructures, including titanium dioxide (TiO2), manganese oxide (MnO2), and molybdenum disulfide (MoS2), exhibit promising electrochemical properties as anodes, cathodes, and electrolytes in lithium-ion batteries, paving the way for next-generation energy storage solutions.…”

Preparation and Thermal Performances of Lauric Acid/Polyvinyl Butyral/Graphene Nanoplates Composite Phase Change Materials

“…These include noncorrosiveness, chemical stability, low ability to undercooling and phase separation, recyclability, and cost-effectiveness. [13] They are widely used in various fields, such as constructions, [6] concentrated solar power systems, [14] photovoltaic-thermal systems, [15] battery thermal management, [16][17][18] and textiles. [19] However, solid-liquid PCMs, especially organic PCMs, still face challenges such as difficulty in shaping, leakage, and low thermal conductivity, which restrict their applications.…”

Hybrid Strategies Using Nanoparticles (Al 2 O 3 ) Along with Different Copper Rod Forms (V, U, And I) For Optimizing the Melting of PCM Inside a Semi- Cylindrical Cell: A Numerical Analysis

“…Solar energy applications use seasonal heat storage facilities in reservoirs or rocky caves [3][4][5], storing heat in rock, concrete or gravel and soil [5][6][7]. Molten salt is also used to store thermal energy during the day for use in bad weather or at night, mainly in solar towers or solar complexes [8][9][10]. Phase change materials (PCM) are also used [11][12][13][14].…”