Stearic Acid/Copper Foam as Composite Phase Change Materials for Thermal Energy Storage

The application of stearic acid in the latent thermal energy storage(LTES) systems is hindered due to its lower heat transfer rate. Stearic acid(SA) was blended with copper foam(CF) of pore numbers per inch(PPI) of 5, 20, and 40 to prepare composite phase change materials via a molten impregnation method. The thermal physical properties including latent heat, phase change temperature, and thermal energy storage density of composites were characterized. The thermogravimetric analysis indicated that the loadages of SA of SA/CF(5 PPI), SA/CF(20 PPI), and SA/CF(40 PPI) were 74.69%, 71.03%, and 63.54%, respectively; The latent heat of SA/CF(5 PPI), SA/CF(20 PPI), and SA/CF(40 PPI) were determined to 139.9 J·g-1, 132.7 J·g-1, and 117.8 J·g-1, respectively. Meanwhile, the infrared thermal images of SA and SA/CF composites were provided to demonstrate the thermal energy storage and dissipation capability intuitively by the temperature response and surface temperature distribution. The infrared thermal images indicated the addition of CF also reduced the fluidity of liquid SA, and the SA/CF(40 PPI) had better internal heat transfer uniformity and thermal diffusion performance than SA/CF(5 PPI) and SA/CF(20 PPI). All these thermal properties suggested SA/CF(40 PPI) has the potential application in the latent thermal energy storage.