3D porous aerogel based-phase change materials with excellent flame retardancy and shape stability for both thermal and light energy storage

As we all known, the problems of easy leakage, poor thermal conductivity and high flammability will hinder the application of phase change materials for energy storage. In this work, a novel multifunctional composite phase change material was prepared via efficient modifications, which has preeminent flame retardancy and shape stability to achieve safe and efficient storage of heat and light energy. As expected, the composite phase change material had excellent thermal energy storage density (163.9 J/g), even the melting enthalpy ratio could reach 91.1%. In comparison with pure PEG, the thermal conductivity has realized improvement as well, and the shape stability of composite phase change materials was significantly promoted, which could be heated at 80 °C for 1 h without the leakage of PEG. In addition, it showed excellent thermal stability and fire resistance, the maximum decomposition rate and the peak heat release rate were decreased by 47% and 34.1%, respectively, compared with pure PEG. More importantly, composite phase change materials realized the storage of light energy on the basis of thermal energy management and utilization, which could absorb and store ultraviolet and visible light during the day, and then release fluorescence slowly for a long time in the dark. To sum up, neoteric multifunctional composite phase change materials have enormous prospects for safe and efficient application in the fields of solar energy acquisition, thermal and light energy storage and thermal management.