All-Solid-State Infrared Electrochromic Devices Based on Thin Metal Films

Infrared electrochromic devices (IR-ECDs) are pivotal for dynamic thermal regulation. However, the quest for all-solid-state IR-ECDs with high stability and a broadly tunable range of emissivity remains a challenge. This study presents the development of an all-solid-state infrared electrochromic device (IR-ECD) with the structure of ITO/H_xWO₃/Ta₂O₅/Pd/Mg₃Ni based on the hydrogen-induced metal–insulator transition of Mg–Ni alloy films. The emissivity modulation is improved by film stack optimization, with changes of 0.32 and 0.47 in the 3–5 and 7.5–14 μm bands, respectively. The introduction of an ultrathin Ti isolation layer between the catalytic and electrolyte layers enhances the cyclic stability. Our findings offer a novel strategy for the design and fabrication of all-solid-state IR electrochromic devices and highlight the potential of Mg–Ni alloy-based all-solid-state IR-ECDs in advanced energy and information fields.