Hydrophilic Ultra-Fine SiC Nanowires Enhance the Performance of Hydrated Salt Phase-Change Energy Storage Materials.

Abstract

In this study, ultrafine linear nanostructured SiC with high wettability and large specific surface area were synthesized via the carbothermal reduction method. These nanowires were impregnated with Na₂SO₄ ⋅ 10H₂O, CaCl₂ ⋅ 6H₂O, MgCl₂ ⋅ 6H2O, and CaMg₂Cl₆ ⋅ 12H₂O to obtain composite phase change materials (CPCMs), which demonstrated improved phase separation and significantly reduced supercooling. In particular, the supercooling degree of CaCl₂ ⋅ 6H₂O was minimized to 0.1 °C. The SiC nanowires effectively prevented issues of dehydration and deliquescence in hydrated salts. The thermal storage capacities of the CPCMs exceeded 90 %, with Na₂SO₄ ⋅ 10H₂O and MgCl₂ ⋅ 6H₂O reaching 107.10 % and 103.35 %, respectively. Furthermore, the CPCMs exhibited greater sensitivity to changes in temperature compared with the pure hydrated salt phase change materials (PCMs). These results indicate that ultra-fine SiC nanowires can act as a versatile carrier for hydrated salt PCMs at low and intermediate temperatures.