Fluoroelastomer‐Engineered Atmospheric Hygroscopic Hydrogels With Adhesive and Anticorrosive Interfaces for Efficient and Stable Evaporative Cooling

ABSTRACT The relentless miniaturization and integration of modern electronics intensify overheating issues, driving the need for advanced thermal management solutions. Sorption‐based evaporative cooling, which utilizes atmospheric hygroscopic hydrogels (AHHs) to capture moisture and release it for heat dissipation, presents a promising passive approach. However, conventional AHH‐based evaporative cooling still faces challenges of poor substrate adhesion and halide salt leakage, leading to high interfacial thermal resistance and equipment corrosion. Here, we report a fluoroelastomer‐engineered atmospheric hygroscopic hydrogel (FAHH) with an adhesive and anticorrosive interface for efficient and stable evaporative cooling. The FAHH exhibits robust adhesion to various substrates via multiple intermolecular interactions, ensuring stable thermal contact, while its hydrophobic and electronegative interface effectively suppresses halide leakage to prevent corrosion. Consequently, the FAHH achieves an average temperature reduction of 11.3°C and a mean cooling power of 343.8 W m ⁻² at 60°C over 5 h. In practical applications, it also reduces the operating temperature of single‐board computer devices by up to 23.7°C (17.2% working performance gain) and that of solar cells under 1 sun illumination by up to 17.4°C (0.8% efficiency improvement). This work provides a promising approach for passive cooling of electronics.