Novel High-Performance and Low-Cost Electrochromic Prussian White Film

Prussian white (PW), due to its low cost, easy synthesis, open structure, and fast ion extraction/interaction, is introduced to the electrochromic field. The PW films were successfully grown on indium tin oxide (ITO) glass by a facial hydrothermal method. Impressively, the PW film exhibits excellent electrochemical cycling stability without obvious decay over 10 000 cycles and a high coloration efficiency of 149.3 cm² C^-1. The film also provides the large optical transmittance contrast (over 70%) in a wide wavelength range of 650-800 nm. Furthermore, the PW film shows the rapid coloration and bleaching response. These results suggest that PW is a promising practical candidate of high-performance electrochromic material.