Temperature‐adaptive Radiative Cooling Coating

ABSTRACT Passive radiative cooling (PRC) technology, a green cooling method requiring no external energy input, shows great potential for application in energy‐efficient buildings. However, it is difficult yet extremely important to quickly switch thermal management performance with the change of as‐applied environments. In this work, a temperature‐adaptive radiative cooling coating based on the polydivinylbenzene (PDVB) fiber‐gelled phase change material (PCM) was designed. It successfully realizes intelligent adjustment of coating reflectivity in 0.3–2.5 µm by the synergistic effect of temperature‐responsive radiative and phase change energy storage properties. When the temperature rises from 30°C (below the phase change temperature) to 60°C (above the phase change temperature), the average reflectivity of the material increases from 53.25% to 72.45%, while having a high emissivity of 95.72% in the atmospheric transparency window (8–13 µm). In outdoor testing, the steel substrate coated with the gel exhibited an average temperature reduction of 12.3°C versus uncoated steel during midday high‐temperature periods. But during evening cooling, it suppresses excessive cooling by reducing reflectivity and releasing PCM latent heat, limiting the average temperature drop to only 0.2°C versus uncoated steel. It provides a novel method for intelligent thermal management.