Phase Change Aerogels Enabled With Passive Radiative Cooling: Toward Intelligent Thermal Management

ABSTRACT Current thermal insulation materials, such as aerogels and foams, encounter significant challenges in managing temperature fluctuations between day and night due to their low heat capacity and poor thermal inertia. This imbalance leads to inadequate cooling during the day and excessive cooling at night, highlighting the need for innovative solutions in energy efficiency. In response to these limitations, we have developed a multifunctional aerogel strategy that integrates passive radiative cooling with phase change materials, enhancing both insulation properties and climate change mitigation efforts. Micron‐scale phase change capsules are embedded within the oriented aerogel walls, serving dual function as scattering units and cold storage cells. This innovative design achieves exceptional solar spectral reflectance of over 96% and infrared emissivity exceeding 95%, while maintaining a low thermal conductivity of less than 40 mW.m −1 K −1 and featuring a high enthalpy of 146.1 J/g. The unique cold storage capabilities enable nocturnal retention of excess cold, which compensates for daytime cooling gaps, thereby reducing heat shocks and enhancing overall temperature comfort throughout the day. This innovative material achieves efficient integration of functions and represents a significant advancement in building energy efficiency, offering promising potential for mitigating climate change through improved thermal management systems.