One million cyclable blue/colourless electrochromic device using K2Zn3[Fe(CN)6]2 nanoparticles synthesized with a micromixer

Well-defined K2Zn3[Fe(CN)(6)](2)-nanoparticles (NPs) synthesized with a micromixer showed robust redox reaction cyclability. Crystal structure analysis revealed that the robustness results from the maintenance of the original rhombohedral crystal structure in the oxidation state. The blue/colourless electrochromic device with the K2Zn3[Fe(CN)(6)](2)-NPs and Prussian blue NPs showed recyclability over 1 million redox reactions.