Synthesis of alumina porous ceramics to enhance heat transfer and control Supercooling in sugar alcohol phase change materials for thermal energy storage

Sugar alcohol phase change materials (PCMs) have garnered extensive attention in the field of medium to low-temperature thermal energy storage due to their high latent heat. However, their application is limited by supercooling and low thermal conductivity. In this paper, a series of porous alumina ceramics with varying porosities (62 % to 83 %) were fabricated using a freeze-casting method as supporting frameworks for loading sugar alcohol phase change materials, resulting in high-performance, leakage-proof, and shape-stabilized sugar alcohol composite phase change materials. The effects of various additives and alumina content on the porosity of the porous ceramics were investigated. The thermal conductivity, phase change property, and supercooling of sugar alcohol composite phase change materials were measured. The thermal conductivity of ET-APC-56 was 4.82 W/(m·K), which was an increase of 690 % compared to erythritol (ET). The phase change enthalpy of ET-APC-28 was 225 J/g, and it still retained 202.8 J/g after 500 thermal cycles. The supercooling of ET-APC-28 was reduced from 59.1 °C to 8.9 °C. Additionally, leakage tests showed no significant leakage in any of the samples. The prepared sugar alcohol composite phase change materials demonstrated excellent thermal performance, indicating broad application prospects in the field of medium to low-temperature phase change thermal energy storage.