Thermal Properties of Disodium Hydrogen Phosphate Dodecahydrate–Coated Metal Foam/Sodium Acetate Trihydrate Composite as Phase Change Material

Salt hydrates, like the sodium acetate trihydrate (SAT), possess a remarkable ability to store copious amounts of thermal energy, thanks to their ingenious utilization of a high latent heat of fusion. This unique property makes them a compelling choice for various energy storage applications. In this study, aluminum and copper foams with pore sizes of 40, 80, and 110 pores per inch (PPI) coated with disodium hydrogen phosphate dodecahydrate were prepared, and their effects on the SAT solidification temperature, latent heat of fusion, and thermal conductivity were investigated. The samples' thermal conductivity was measured using the guarded heat flow method. Thermal properties, including latent heat of fusion and supercooling were measured using the T-History method. The results showed that the metal foam matrix is an effective method of enhancing the thermal conductivity of SAT while occupying a small volume of the composite. The copper foam with a PPI of 80 was able to increase the effective thermal conductivity to 2.62 W/(m⋅K), an increase of 388.15% compared to pure SAT while occupying approximately 6.5% of the composite volume. The T-History results showed a solidification temperature of 57.52 °C along with a super cooling of 3.28 °C for the same sample set. Furthermore, it was also found that copper samples significantly outperformed the aluminum ones, despite the higher porosity.