Zn-Electrochromic Device with Hierarchical Aerogel and Phase-Change Material Enables Dynamic Infrared Camouflage at...

Effective infrared camouflage is critical for military platforms operating in thermally extreme environments, such as high-speed aircraft skins, armored vehicle surfaces, engine external parts, where surface temperatures can exceed 200°C. Conventional infrared camouflage systems, primarily based on liquid-electrolyte electrochromic devices, fail under extreme heat due to the thermal instability of liquid electrolytes. Here, we overcome this limitation by developing a solid-state, sandwich-structured device that combines a Zn²⁺-based electrochromic layer with two thermally protective components: an ultralow-conductivity polyimide aerogel (29.7 mW m^-1 K^-1) and a high-enthalpy polyimide/polyethylene glycol phase-change composite (150.1 J g^-1). This integrated design achieves dynamic infrared modulation with emissivity contrasts of 0.63 (3-5 µm bands) and 0.71 (8-14 µm bands), while maintaining stable operation at 250°C and surviving short-term exposure to 300°C. The system decouples optical control from thermal degradation, a key advance over existing approaches, facilitating real-time signature adaptation on high-temperature military platforms. Rapid switching (<10 s), near-zero static power consumption in bistable states, and reversibility over thousands of cycles further support its practical deployment. By unifying electrochromic tuning, thermal insulation, and latent heat buffering in a single architecture, our work opens a new route toward intelligent thermal management in extreme conditions.