Electrochromic Device and Method for Manufacturing Electrochromic Device

Abstract

The present invention relates to devices that provide a color change under the influence of an electric voltage, in particular to an electrochromic device and a method for manufacturing such a device. Disclosed is a method for manufacturing an electrochromic device comprising at least two electrodes that are flexible and optically transparent with a hermetically closed space between the electrodes filled with an electrochromic composition, which may contain transparent and insoluble microparticles that function as spacers.

What is claimed is: 
     
         1 . An electrochromic device comprising:
 (a) at least two flexible electrodes, wherein at least one of the at least two flexible electrodes is optically transparent; and   (b) a hermetically closed space residing between the at least two flexible electrodes,   wherein the hermetically closed space between the at least two flexible electrodes is filled with an electrochromic composition, the electrochromic device being manufactured by a method comprising:   (1) preparing an initial deaerated electrochromic composition in the form of an electrochromic dispersion system containing a colloid,   wherein a continuous phase of the electrochromic dispersion system comprises,
 an electrochromic solution comprising a liquid solvent, 
 a cathodic component, 
 an anodic component, 
 a polymerizable low-shrinkage monomer or a monomer mixture comprising a cationic ring-openable polymerization monomer, and 
 a polymerization thermal activator, 
   wherein a non-continuous phase, of said electrochromic dispersion system, consists of a dispersible polymer, wherein said non-continuous phase is said colloid, and   wherein the initial electrochromic composition is deaerated to remove the dissolved oxygen of air that was introduced with the dispersible polymer;   (2) filling the hermetically closed space between the at least two flexible electrodes with the deaerated initial electrochromic composition; and   (3) sealing the hermetically closed space between the at least two flexible electrodes.   
     
     
         2 . The electrochromic device of  claim 1 , wherein the continuous phase of the electrochromic dispersion system further comprises an indifferent electrolyte. 
     
     
         3 . The electrochromic device of  claim 1  wherein,
 said liquid solvent comprises propylene carbonate, 
 said cathodic component comprises 1,1′-dibenzyl-4,4′-bipyridinium diperchlorate, and 
 said anodic component comprises 1,1′-diethylferrocene. 
 
     
     
         4 . The electrochromic device of  claim 1 , further comprising a plurality of transparent spacers positioned within said hermitically closed space, wherein said transparent spacers are insoluble in said electrochromic composition, and provide a predetermined distance between the at least two flexible electrodes. 
     
     
         5 . The electrochromic device of  claim 4 , wherein said transparent spacers have a refractive index that is close to the refractive index of said electrochromic composition. 
     
     
         6 . The electrochromic device of  claim 5 , wherein said transparent spacers comprise at least one of glass microparticles or polymeric microparticles, and each transparent spacer independently has dimensions of from 20 μm to 200 μm. 
     
     
         7 . The electrochromic device of  claim 1 , wherein each flexible electrode independently comprises a polymeric substrate and a transparent electrically conductive layer on a surface of said polymeric substrate, wherein said transparent electrically conductive layer faces said hermitically sealed space. 
     
     
         8 . The electrochromic device of  claim 7 , wherein each transparent electrically conductive layer independently comprises at least one of doped indium oxide (In 2 O 3 ) or doped tin oxide (SnO 2 ). 
     
     
         9 . The electrochromic device of  claim 7 , wherein each polymeric substrate independently comprises polyethylene terephthalate.