Electrochromic composition and electrochromic device using same

Abstract

Electrochromic compositions for use in devices with electrically controlled absorption of light such as light filters of variable optical density, light emission modulators, and information image displays. The described electrochromic compositions may be used, for example, for creating light-transmitting coatings of buildings for controlling indoor microclimate by regulating the flow of natural light. Specifically, described is an exemplary organic electrochromic composition that is based on biocompatible and biodegradable components and is characterized by an increased service life, a high rate of light-transmission change. The described electrochromic compositions may be prepared in a wide range of light-absorption spectra and coating colors.

What is claimed is: 
     
         1 . An electrochromic device comprising:
 a first electrode and a second electrode;   an electrochromic composition layer disposed between the first and second electrodes and configured to change color in response to an applied voltage between the first and second electrodes, the electrochromic composition layer comprising the following components:
 a cathodic component comprising one of 1,1′-dimethyl-4,4′-dipyridinium, 1,1′-diethyl-4,4′-dipyridinium or 1,1′-dibenzyl-4,4′-dipyridinium, and one of PF 6   − , CF 3 SO 3   −  or (CF 3 SO 2 ) 2 N − , 
 an anodic component comprising a ferrocene, 
 a polymeric thickener, 
 an antioxidant, and 
 an ultraviolet filter. 
   
     
     
         2 . The electrochromic device of  claim 1 , wherein the electrochromic composition layer is a single layer contacting the first and second electrodes and further comprising a solvent having the components mixed or dissolved therein. 
     
     
         3 . The electrochromic device of  claim 1 , wherein the antioxidant comprises one or more of a polyphenol, a sterically hindered phenol and 2,6-di-tert-butyl-4-methylphenol (ionol). 
     
     
         4 . The electrochromic device of  claim 1 , wherein the antioxidant comprises one or more of a benzophenone and a cinnamate. 
     
     
         5 . The electrochromic device of  claim 1 , wherein the cathodic component is present at a concentration of 0.4-0.3.6 mass % on the basis of a total mass of the electrochromic composition layer. 
     
     
         6 . The electrochromic device of  claim 1 , wherein the anodic component is present at a concentration of 0.3-3.0 mass % on the basis of a total mass of the electrochromic composition layer. 
     
     
         7 . The electrochromic device of  claim 1 , wherein the solvent comprises one or more of propylene carbonate, N-methylpyrrolidone, polyethylene glycol and an ester thereof. 
     
     
         8 . The electrochromic device of  claim 1 , wherein the anodic component comprises 1,1′-diethylferrocene. 
     
     
         9 . The electrochromic device of  claim 1 , further comprising a polymeric thickener comprising a copolymer of methylacrylate and one of a polylactic acid or poly-3-hydroxybutyrate. 
     
     
         10 . The electrochromic device of  claim 1 , wherein the electrochromic device is configured such that the electrochromic composition layer visibly changes color in about 30 seconds under about 1.5V. 
     
     
         11 . The electrochromic device of  claim 1 , wherein the electrochromic composition layer has a thickness of 25 μm to 200 μm. 
     
     
         12 . The electrochromic device of  claim 1 , further comprising an electrode reaction accelerator additive comprising a ferrocenium salt. 
     
     
         13 . The electrochromic device of  claim 1 , further comprising a biodegradable polymer comprising one of poly lactic acid or poly-3-hydroxybutyrate. 
     
     
         14 . An electrochromic device comprising:
 a first electrode and a second electrode;   an electrochromic composition layer disposed between the first and second electrodes and configured to change color in response to an applied voltage between the first and second electrodes, the electrochromic composition layer comprising the following components:
 a solvent comprising one of propylene carbonate, N-methylpyrrolidone, polyethylene glycol, or an ester thereof, 
 a cathodic component comprising a quaternary salt comprising one of 1,1′-dimethyl-4,4′-dipyridinium, 1,1′-diethyl-4,4′-dipyridinium or 1,1′-dibenzyl-4,4′-dipyridinium and one of BF 4   − , PF 6   − , ClO 4   − , or an organic anion, 
 an anodic component comprising one of ferrocene or 1,1′-diethylferrocene, and 
 a biodegradable polymer comprising one of poly lactic acid or poly-3-hydroxybutyrate. 
   
     
     
         15 . The electrochromic device of  claim 14 , wherein the electrochromic composition layer is a single layer contacting the first and second electrodes and comprising the solvent having the cathodic component, the anodic component and the biodegradable polymer mixed or dissolved therein. 
     
     
         16 . The electrochromic device of  claim 14 , wherein the cathodic component comprises 1,1′-diethyl-4,4′-dipyridinium. 
     
     
         17 . The electrochromic device of  claim 14 , wherein the organic anion is one of CF 3 SO 3 — or (CF 3 SO 2 ) 2 N − . 
     
     
         18 . The electrochromic device of  claim 14 , wherein the quaternary salt is present at a concentration of 0.4-0.3.6% on the basis of a total mass of the electrochromic composition layer.