Incorporation form-stable phase change material with passive radiative cooling emitter for thermal regulation

Passive radiative cooling (RC) can remove heat without any external energy. Nonetheless, it would bring redundant heating energy consumption under low temperature. In this work, dynamic radiative cooling material consisting selective super-hydrophobic radiative cooling emitter (SRCE) and phase change material (PCM) was proposed. PCM (dodecanol) was vacuum-impregnated into porous nickel foam (PCM@NF), and then stitched with SRCE (PCM@NF@SRCE). PCM@NF had the phase change temperature near the comfort temperature for human body (∼25 ℃) and large latent heat. Moreover, the SRCE has high solar reflectivity (0.93) and superb selective emission property (emissivity in atmospheric window : 0.83, emissivity outside atmospheric window: 0.49). Besides, the SRCE exhibited excellent super-hydrophobicity (162.2°), mechanical robustness and UV resistance. During outdoor measurement, the PCM@NF@SRCE achieved better sub-ambient cooling under hot weather while kept higher temperature in cold weather compared with bare SRCE. In addition, the energy saving simulation verified the energy saving performance of the PCM@NF@SRCE in both hot and cold weather. The integration of PCM and SRCE shows promising application in various climates.