Ultraflexible, stretchable and fast-switching electrochromic devices with enhanced cycling stability

to form an electrochromic device, which simultaneously displays a rapid switching time (0.75 s/1.82 s for bleaching/coloring) and high cyclic performance (86% retention of the initial optical contrast after cycling for 30 000 s). In addition, our electrode can also be fabricated on various flexible substrates, such as polyethylene cling wrap, polydimethylsiloxane and Ecoflex, with sustained electrochromic properties after bending, twisting, stretching and even strong kneading. Our work provides new opportunities for the next generation of flexible and wearable electronics applied on various flexible substrates.