A visible-to-infrared broadband flexible electrochromic device based polyaniline for simultaneously variable optical and thermal management

A visible-to-infrared broadband flexible electrochromic device based on H2SO4-doped polyaniline films has been constructed for simultaneously variable optical and thermal management. Upon electrochemically manipulating, the demonstrated electrochromic device could change from a wide bandgap semiconductor to an insulator, causing the device to transform from a high thermal emitter with dark green to an optical reflector with bright yellow. High infrared emission changes of 0.4 and 0.3 for the device are observed at the wavelength ranges of 8–14 μm and 2.5–25 μm, respectively, which are higher than most reported electrochromic devices. A promising cycling stability and flexibility of the device are also observed. The thermal imaging results reveal that the device can be electrochemically and reversibly tuned to blend them with their environment. Furthermore, both the theoretical calculation and experimental results demonstrate that the device exhibits different heat transfer rates, facilitating the thermal management of the indoor object. The illustrated capabilities of the device make the electrochromic device highly promising for the optical management in visible-infrared regions and thermoregulation in indoor environment.