Thermal stability of sodium nitrate microcapsules for high-temperature thermal energy storage

Study on the microstructures and thermal properties of SiO 2 @ NaNO 3 microcapsule thermal storage materials

“…The results were consistent with the decomposition temperature of raw materials and NaNO 3 . 25,38 It was worth mentioning that the T peak of SiO 2 @NaNO 3 microcapsules in the decomposition decreased slightly with the increase of the silica addition, which was due to the increase of thermal conductivity. Furthermore, the residual amount of sodium nitrate was 28%, and the residual amount of the M-1 sample was up to 45% after the second decomposition, which was due to the protection of silica shell in preventing decomposition of NaNO 3 .…”

“…The NaNO 3 showed the weight loss of about 72% after the second step decomposition due to the decomposition. 25,38 For the first step decomposition, the weight loss of the silica was about 5.4%, which could be owing to the decomposition of raw materials. For the SiO 2 @NaNO 3 microcapsules, the mass loss was increased with the addition of silica.…”

“…23,24 Molten salt is the promising latent thermal energy storage (LTES) medium at middle temperature applications used in solar thermal power systems. [25][26][27] The high melting temperature PCM was widely used as direct heat transfer fluids due to the characteristics of non-flammability, low toxicity and high thermal stability. 26,28 In particular, NaNO 3 has the appropriate melting point, low storage unit cost, high energy storage capacity with minimum subcooling making it a core material suitable for heat storage and heat transfer fluid (HTF) in CSP systems.…”

“…Based on the research status, the microencapsulated NaNO 3 composites with silica shell can be served as thermal transfer medium in CSP system due to the high thermal storage capacity and high thermal stability. 17,25,38,39 However, most of microencapsulation works of silica were performed in aqueous solutions by sol-gel method, which was not compatible with watersoluble salt. Take advantage of the feature that water was not consumed during the hydrolytic condensation process of TEOS.…”

Nanoencapsulation of phase change materials for advanced thermal energy storage systems

“…28 Energy storage can also be employed to improve the efficiency of concentrated solar power, using high temperature PCMs with transition temperatures above 300 °C (salts or metals). 29 Few attempts have been made to encapsulate high temperature PCMs on the macro 30 , 31 and micro 32 scale. This review (i) surveys the main encapsulation approaches for nanostructured and multifunctional capsule shells and (ii) focuses on the nanoencapsulation of low temperature paraffin waxes and salt hydrate.…”