A high-contrast electrochromic film with fast switching speed based on large-scale grown nanorod array

Electrochromic films are intelligent material that allows for adjustable transparency and light reflection and possesses broad application prospects. Therefore, it holds significant research significance and application value in the development of science and technology. In this work, we make polyaniline/nickel oxide (PANI/NiO) composite films by growing a nanorod (NR) array on the surface of aniline monomer electropolymerized films. The synthesized pore architecture provides an increased density of ion-conducting pathways, leading to reduced response times. The electrochromic film exhibits remarkable reversible color-switching characteristics, transitioning from a transparent light yellow state to an opaque black–purple state, with a high optical modulation range of approximately 72% and an impressively rapid coloring/bleaching time of 0.61 s/0.73 s. These results may be used in fields such as architecture, automobiles, aerospace, and others that have received extensive research and practical application and can bring about better energy conservation and environmental adaptability in future.