Electrochromic device employing gel or solid polymers having specific channel direction for the conduction of ions
An electrochromic device in which specific channel direction for the conduction of ions is implemented. As a result ionic crosstalk between display pixels is greatly reduced and unwanted transient coloration effects are minimized. Further, specific gel, polymer, or ionic liquid solutions can greatly eliminate the corrosive effects associated with the use of electrolyte salt solutions.
1. An electrochromic display comprising a first electrode, a second electrode, an anisotropically conducting electrolyte, and a control element;
the first electrode including a substrate, a patterned conductor, and a first nanostructured metal oxide film with an adsorbed chromophoric redox material;
the second electrode including a substrate, a conductor, and a second nanostructured metal oxide film;
the anisotropically conducting electrolyte including a polymer film and an electrolyte, the anisotropically conducting electrolyte is disposed between and operatively connects the first and second electrodes;
the control element operatively connected to either the first or second electrodes and application of voltage or current via the control element modulates the redox state of the chromophoric redox material.
2. The electrochromic display of claim 1 , the control element is a direct drive.
3. The electrochromic display of claim 1 , the control element is a passive matrix where the first and second electrodes are arranged in orthogonal columns and rows; the overlapping regions where the columns and rows overlap defining switchable pixel areas; and application of voltage or current via the control element to a particular column and a particular row modulates the redox state of the chromophoric material in the switchable pixel area where the particular column and the particular row overlap.
4. The electrochromic display of claim 1 , the control element is an active matrix control element.
5. The electrochromic device of claim 4 , the active matrix control element is a thin film transistor.
6. The electrochromic device of claim 1 , the polymer film including an anisotropic polymer matrix, pores, and the electrolyte is within the pores; the pores aligned perpendicularly to the first and second electrodes.
7. The electrochromic device of claim 6 , the anisotropic polymer matrix is self-assembling.
8. The electrochromic device of claim 6 , the anisotropic polymer matrix is formed by precipitation from working solvents.
9. The electrochromic device of claim 8 , the working solvents selected from the group consisting of N-methylpyrrolidinone, acetone, gamma-butyrolactone, methoxypropionitrile, dimethylformamide, dimethylacetamide, alcohols, and glycol ethers.
10. The electrochromic device of claim 6 , the anisotropic polymer matrix is formed by solidification.
11. The electrochromic device of claim 6 , the anisotropic polymer matrix including a polymer selected from the group consisting of poly (vinylidene fluoride), copolymers of vinylidene fluoride and hexafluoropropylene, poly (ethylene oxide), poly (vinyl alcohol), ethylcellulose, hydroxypropylcellulose, nitrocellulose, and poly (methylmethacrylate).
12. The electrochromic device of claim 6 , the electrolyte is selected from the group consisting of a solution of an ionic compound and an ionic liquid.
13. The electrochromic device of claim 6 , the electrolyte is selected from the group consisting of gamma-butyrolactone, and methoxypropionitrile.
14. The electrochromic device of claim 1 , the anisotropically conducting electrolyte including a polymer film that is self assembling from polymer and linker moieties; the polymer and linker moieties bind to each other to each other to form chains; the polymer of one chain associating with polymer of another chain to form a polymer section; the linker of one chain associating with the linker of another chain to form a linker section; and the polymer and linker sections are arranged perpendicularly to the first and second electrodes.
15. The electrochromic device of claim 14 , the polymer sections supporting ion conductivity and the linker sections do not support ion conductivity.
16. The electrochromic device of claim 14 , the polymer includes polyethylene.
17. The electrochromic device of claim 14 , the linker moiety includes a chemical moiety of the formula
18. The electrochromic device of claim 1 , the electrolyte is a solvent with a dissolved salt.
19. The electrochromic device of claim 18 , the solvent is selected from the group consisting of acetonitrile, propylene carbonate, and gamma-butyrolactone.
20. The electrochromic device of claim 18 , the salt selected from the group consisting of lithium, sodium and ammonium salts.