Tungsten oxide nanowires and polyaniline hybrid film-based electrochromic device with multicolor display and enhanced capacitance

Electrochromic devices (ECDs) have exhibited promising applications in the fields of energy-saving intelligent buildings and next-generation displays because of their simple structure, low power consumption, and multicolor displays. W18O49/polyaniline (PANI) hybrid films are prepared and assembled to ECDs. Compared with pure PANI and W18O49 films, the hybrid film exhibits superior electrochemical and electrochromic performance, including high optical modulation (70.2%), large areal capacity (79.6 mF/cm2), and good capacitance retention. The excellent electrochemical and electrochromic performance is ascribed to the formation of the donor (PANI)-acceptor (W18O49) pair, the porous structure in the nanowires, and the large surface area, which enhance electron delocalization of the W18O49/PANI, improve the ion diffusion rate, and increase the charge storage sites. Furthermore, benefitting from the outstanding optical, electrical, and multifunctional properties, the W18O49/PANI hybrid film-based ECD platform is expected to play an important role in electrochromism and energy storage.