Spectroelectrochemical and adhesion properties of chemically synthesized ion conducting poly (vinyl butyral) in Prussian blue and poly (3, 4-ethylenedioxythiophene) laminated electrochromic glazing

A novel laminated electrochromic device (ECD) with a chemically synthesized ion conducting-poly (vinyl butyral) (CSIC-PVB) electrolyte is demonstrated. The anodically coloring material and the cathodically coloring material of the device are Prussian blue (PB) and poly (3, 4-ethylenedioxythiophene) (PEDOT) thin films, respectively. From the view of the structure, a laminated electrochromic glazing demands solid polymer electrolyte with both excellent sealing and ionic conductivity properties. The ionic conductivities of the CSIC-PVB films vary in the order of 10−3 down to 10−6 S/cm, whereas the adhesion strengths of these ion conducting PVB interlayers change from 3 to 11 N/mm2. The ionic conductivity and the adhesion of the CSIC-PVB films are proportional to the amount of ionic segments incorporated into the polymer backbone. This PB/CSIC-PVB/PEDOT laminated ECD has an optimal absorbance change at 620 nm. The ECD provides a 39.8% transmittance change (ΔT) at the potential range between 1.0 V and − 1.1 V (PEDOT vs. PB), with a bleaching time of 1.2 s and a darkening time of 1.5 s. And the coloration efficiency at 620 nm of the device is calculated to be 270.8 cm2/C.