A complementary electrochromic device based on Prussian Blue and Tungsten Trioxide: The influence of switching time operation on high performance and long-term stability

The sustainability of electrochromic devices has been heavily focused on both novel materials and electrolytes. Nonetheless, profound research into the operation of electrochromic devices have typically gone unnoticed. Accordingly, there is still a scarcity of research related to a systematic approach to driving principles of electrochromic devices such as the balanced electrochemical process between the anodic and the cathodic electrodes. Based on fundamental electrochemistry, there are three possible causes of poor performance and cycle stability in an electrochromic device: (1) charge is not equally shuttled between Prussian blue (PB) and tungsten trioxide (WO3), (2) irreversible ions are trapped within PB and/or WO3, and (3) PB and/or WO3 deterioration. Herein, this study discovered the impact of switching time operation on a complementary electrochromic device based on PB and WO3, providing a potentially novel direction for enhancing and controlling the electrochromic performance in smart windows or display applications.