Electrochromic media with concentration-enhanced stability, process for the preparation thereof and use in electrochromic devices
First Claim
Patent Images
1. An electrochromic medium, comprising:
- a) a solventb) an anodic electroactive material which exhibits at least two chemically reversible waves in a cyclic voltammogram in said solvent at room temperature,c) a cathodic electroactive material which exhibits at least two chemically reversible waves in a cyclic voltammogram in said solvent at room temperature;
wherein at least one of said electroactive materials is electrochromic, and wherein the electroactive material having the smaller potential difference between the chemically reversible waves has a concentration in the electrochromic medium greater than that required to achieve a balanced concentration.
1 Assignment
0 Petitions
Accused Products
Abstract
Increased stability of electrochromic devices containing an electrochromic medium having two or more electroactive compounds is accomplished by establishing current limiting concentrations of electroactive compounds with the larger redox potential difference. A process for production of electrochromic devices uses targeted concentrations of electroactive materials during preparation of the electrochromic medium which results in substantially no devices being produced wherein the current is limited by an electroactive compound having a low redox potential difference.
196 Citations
42 Claims
-
1. An electrochromic medium, comprising:
-
a) a solvent b) an anodic electroactive material which exhibits at least two chemically reversible waves in a cyclic voltammogram in said solvent at room temperature, c) a cathodic electroactive material which exhibits at least two chemically reversible waves in a cyclic voltammogram in said solvent at room temperature; wherein at least one of said electroactive materials is electrochromic, and wherein the electroactive material having the smaller potential difference between the chemically reversible waves has a concentration in the electrochromic medium greater than that required to achieve a balanced concentration. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 19, 20, 21, 22, 28, 29, 30, 31)
-
-
10. An electrochromic medium comprising
a) an anodic electroactive material, b) a cathodic electroactive material, wherein at least one of said electroactive materials is electrochromic, wherein one of said electroactive materials has only one electrochemically activated state, and wherein a second electroactive material has at least two chemically electrochemically activated states, and wherein the electroactive material with at least two electrochemically activated states has a concentration in the electrochromic medium greater than that required to achieve a balanced concentration.
-
14. An electrochromic medium, comprising:
-
a) an anodic electroactive material, b) a cathodic electroactive material, wherein one of said anodic electroactive material(s) and said cathodic electroactive material(s) has an electrochemically activated state which exhibits greater reactivity than the electrochemically activated state of other of said electroactive materials, wherein the electroactive material exhibiting said greater reactivity is present in concentration greater than that required to achieve a balanced concentration. - View Dependent Claims (15, 16, 17, 18, 25, 26, 27, 34, 35, 36)
-
-
37. A process for the preparation of an electrochromic device wherein an electrochromic medium is introduced into a cavity in said device, said electrochromic medium containing at least one anodic electroactive compound and at least one cathodic electroactive compound, at least one of said electroactive compounds being an electrochromic compound, the improvement comprising:
adjusting the concentrations of said electroactive compounds to establish an increased relative concentration of the electroactive material having the smaller redox potential difference such that said increased concentration is greater than that required to achieve a balanced concentration. - View Dependent Claims (38, 39, 40, 41, 42)
Specification