Preparation and Performance Improvement of Phase Change Materials with Skin-Flesh Structure Inspired by Loofah

Leakage and low thermal conductivity limit the application of molten salts in thermal energy storage (TES) systems. Inspired by the skin-flesh structure of loofah, a porous ceramic with dense skin was designed and prepared. The dense skin prevents molten salt leakage, and the porous ceramic enhances its thermal conduc-tivity. The organic foam impregnation method was used to prepare the porous ceramic, and a layer of SiC slurry was coated on the surface of the porous ceramic. The resulting construct was sintered to form a skin-flesh porous ceramic (SFPC). Solar salt was then directly injected into the SFPC to create a skin-flesh composite phase change material (SF-CPCM). The results showed that leakage of molten salt was prevented when the SiC particle size in the skin slurry was less than 6 & mu;m. The SF-CPCM demonstrated a thermal conductivity of 2.39 W/m & BULL;K, with a porous ceramic porosity of 80%. The SF-CPCM exhibits the best heat transfer performance performance among the four forms of molten salt encapsulation. After 500 thermal cycles, the shape and thermal performance of the SF-CPCM remained stable. The skin-flesh structure proposes a new strategy for the development of TES materials.