Durability-reinforced electrochromic device based on surface-confined Ti-doped V2O5 and solution-phase viologen

A novel durability-reinforced electrochromic device (ECD) is described, in which the electrochromic materials remain in different physical form. Solution-phase ethyl viologen is used as the working electrochromic material, and modified Ti-doped V2O5 is utilized as counter electrochromic material. Electrochromic and spectral performances of the device are recorded here. The ECD shows good electrochromic performances in the visible and utraviolet region. Particularly, it's worth mentioning that the ECD could work for 250,000 cycles at 60 °C, with transmittance of 70% and 8% between bleached and colored states at the wavelength of 600 nm, which shows remarkable long term stability. The excellent durability are mainly attributed to the reasonable choice of matching states and durability reinforced Ti-V2O5 film: the color change, charge capacity and switching speed of the viologen solution could be controlled through adjusting the concentration, and the addition of Ti provides excellent stability due to the distorted V2O5 layer structure.