Electrolytes for electrooptic devices comprising ionic liquids

• US 20040021928A1
• Filed: 06/20/2003
• Published: 02/05/2004
• Est. Priority Date: 06/21/2002
• Status: Active Grant

• Current Assignee: Ajjer, LLC, TRIAD National Security, LLC
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Agrawal, Anoop, Cronin, John P., Burrell, Anthony K., Warner, Benjamin P., McCleskey, T. Mark, Tonazzi, Juan C. L.
• Granted Patent: US 6,853,472 B2
• Time in Patent Office: Days
• US Class Current: 359/265
• CPC Class Codes: C07C 311/48 having nitrogen atoms of sulfonamide groups further bound to another hetero atom
• CPC Class Codes: C07C 317/04 of an acyclic saturated carbon skeleton
• CPC Class Codes: C07D 213/22 containing two or more pyridine rings directly linked together, e.g. bipyridyl
• CPC Class Codes: C09B 57/00 Other synthetic dyes of known constitution
• CPC Class Codes: G02F 1/1503 caused by oxidation-reduction reactions in organic liquid solutions, e.g. viologen solutions
• CPC Class Codes: G02F 2001/15145 the electrochromic layer comprises a mixture of anodic and cathodic compounds

Abstract

Electrolyte solutions of soluble bifunctional redox dyes in molten salt solvent may be used to prepare electrooptic devices with enhanced stability toward ultraviolet radiation. The solvents include lithium or quaternary ammonium cations, and perfluorinated sulfonylimide anions selected from trifluoromethylsulfonate (CF₃SO₃⁻), bis(trifluoromethylsulfonyl)imide ((CF₃SO₂)₂N⁻), bis(perfluoroethylsulfonyl)imide ((CF₃CF₂SO₂)₂N⁻) and tris(trifluoromethylsulfonyl)methide ((CF₃SO₂)₃C⁻).

Claims

1. An electrolyte solution having a Tg of less than about −

40°

C., comprising at least one bifunctional redox dye dissolved in ionic liquid solvent.

2. The electrolyte solution of claim 1, wherein said bifunctional redox dye comprises at least one redox active anodic moiety and at least one redox active cathodic moiety.

3. The electrolyte solution of claim 1, wherein said bifunctional redox dye comprises at least one energy receptor moiety and at least one redox active anodic moiety, at least one energy receptor moiety and at least one redox active cathodic moiety, or at least one energy receptor moiety and at least one redox active anodic moiety and at least one redox active cathodic moiety.

4. The electrolyte solution of claim 1, wherein said ionic liquid solvent comprises at least one cation selected from the group consisting of lithium cation and quaternary ammonium cations, wherein said quaternary ammonium cations are selected from the group consisting of pyridinium, pyridazinium, pyrimidinium, pyrazinium, imidazolium, pyrazolium, thiazolium, oxazolium, triazolium, tetraalkylammonium, N-methyl morpholinium, cations of the formula [(CH₃CH₂)₃N(R₁)]⁺, wherein R₁ is alkyl having 2-10 carbons, cations of the formula [(CH₃)₂(CH₃CHCH₃)N(R₂)]⁺, wherein R₂ is alkyl having 2-10 carbons, cations having the structural formula

5. The electrolyte solution of claim 1, wherein said ionic liquid comprises at least one anion selected from the group consisting of trifluoromethylsulfonate (CF₃SO₃⁻

), bis(trifluoromethylsulfonyl)imide ((CF₃SO₂)₂N⁻

), bis(perfluoroethylsulfonyl)imide ((CF₃CF₂SO₂)₂N⁻

) and tris(trifluoromethylsulfonyl)methide ((CF₃SO₂)₃C⁻

).

6. The electrolyte solution of claim 2, wherein said anodic moiety of said bifunctional redox dye comprises a pyrazoline, metallocene, phenylenediamine, benzidine, phenoxadine, phenothiazine, tetrafulvalene or phenazine, and said cathodic moiety of said bifunctional redox dye comprises a viologen or anthraquinone.

7. The electrolyte solution of claim 1, wherein said bifunctional redox dye is a compound having the structural formula

8. The electrolyte solution of claim 3, wherein said bifunctional redox dye comprises a redox active moiety comprising a pyrazoline, metallocene, phenylenediamine, benzidine, phenoxadine, phenothiazine, tetrafulvalene, phenazine, viologen or anthraquinone, and an energy receptor moiety comprising a benzophenone, benzotraizole, or cyanoacrylate.

9. The electrolyte solution of claim 1, wherein said bifunctional redox dye comprises a compound having the formula

[Cat₁][M]

wherein M represents a metal salt comprising titanium (III), vanadium (III), vanadium (IV), iron (II), cobalt (II), copper (I), silver (I), indium (I), tin (II), antimony (III), bismuth (III), cerium (III), samarium (II), dysprosium (II), ytterbium (II), or europium (II);

wherein Cat₁ represents a ligand having the structural formula

10. The electrolyte solution claim 1, further comprising at least one additive selected from the group consisting of non-ionic cosolvents, polymers, thixotropic agents, and UV stabilizers.

11. An electro-optic device comprising at least one chamber and, as the electrolyte medium inside the chamber, an electrolyte solution having a Tg of less than about −

40°

C. and comprising at least one bifunctional redox dye dissolved in an ionic liquid solvent.

12. The electro-optic device of claim 11, wherein said bifunctional redox dye comprises at least one redox active anodic moiety and at least one redox active cathodic moiety.

13. The electro-optic device of claim 11, wherein said bifunctional redox dye comprises at least one energy receptor moiety and at least one redox active anodic moiety, at least one energy receptor moiety and at least one redox active cathodic moiety, or at least one energy receptor moiety and at least one redox active anodic moiety and at least one redox active cathodic moiety.

14. The electro-optic device of claim 11, wherein said ionic liquid comprises at least one cation selected from the group consisting of lithium cation and quaternary ammonium cations, wherein said quaternary ammonium cations are selected from the group consisting of pyridinium, pyridazinium, pyrimidinium, pyrazinium, imidazolium, pyrazolium, thiazolium, oxazolium, triazolium, tetraalkylammonium, N-methyl morpholinium, cations of the formula [(CH₃CH₂)₃N(R₁)]⁺, wherein R₁ is alkyl having 2-10 carbons, cations of the formula [(CH₃)₂(CH₃CHCH₃)N(R₂)]⁺, wherein R₂ is alkyl having 2-10 carbons, cations having the structural formula

15. The electro-optic device of claim 11, wherein said ionic liquid comprises at least one anion selected from the group consisting of trifluoromethylsulfonate (CF₃SO₃⁻

), bis(trifluoromethylsulfonyl)imide ((CF₃SO₂)₂N⁻

), bis(perfluoroethylsulfonyl)imide ((CF₃CF₂SO₂)₂N⁻

) and tris(trifluoromethylsulfonyl)methide ((CF₃SO₂)₃C⁻

).

16. The electro-optic device of claim 12, wherein said anodic moiety of said bifunctional redox dye comprises a pyrazoline, metallocene, phenylenediamine, benzidine, phenoxadine, phenothiazine, tetrafulvalene or phenazine, and said cathodic moiety of said bifunctional redox dye comprises a viologen or anthraquinone.

17. The electro-optic device of claim 11, wherein said bifunctional redox dye is a compound having the structural formula

18. The electrolyte solution of claim 13, wherein said bifunctional redox dye comprises a redox active moiety comprising a pyrazoline, metallocene, phenylenediamine, benzidine, phenoxadine, phenothiazine, tetrafulvalene, phenazine, viologen or anthraquinone, and an energy receptor moiety comprising a benzophenone, benzotraizole, or cyanoacrylate.

19. The electrolyte solution claim 11, further comprising at least one additive selected from the group consisting of non-ionic cosolvents, polymers, thixotropic agents, and UV stabilizers.

20. The electrolyte solution of claim 11, wherein said bifunctional redox dye comprises a compound having the formula

[Cat₁][M]

wherein M represents a metal salt comprising titanium (III), vanadium (III), vanadium (IV), iron (II), cobalt (II), copper (I), silver (I), indium (I), tin (II), antimony (III), bismuth (III), cerium (III), samarium (II), dysprosium (II), ytterbium (II), or europium (II);

wherein Cat₁ represents a ligand having the structural formula

21. A compound having the structural formula

22. A compound having the structure the formula, wherein said bifunctional redox dye comprises a compound having the formula

[Cat₁][M]

wherein M represents a metal salt comprising titanium (III), vanadium (III), vanadium (IV), iron (II), cobalt (II), copper (I), silver (I), indium (I), tin (II), antimony (III), bismuth (III), cerium (III), samarium (II), dysprosium (II), ytterbium (II), or europium (II);

wherein Cat, represents a ligand having the structural formula

23. A method for filling an empty electrooptic device with fluid comprising warm ionic liquid electrolyte solution, the device having relatively closely spaced plates, each plate having an inwardly facing conductive surface, the plates being sealed around their periphery by a seal that encloses an area of each plate, comprising:

(a) introducing a small opening into the seal of an empty device;

(b) placing the empty device into a chamber along with a container of fluid comprising ionic liquid electrolyte solution;

(c) evacuating the chamber;

(d) lowering the empty device into the fluid such that the opening in the seal is located under the surface of the fluid;

(e) warming at least a portion of the fluid to a temperature of at least 40°

C.;

(f) exposing the fluid to a gas pressure greater than the pressure in the empty device to send the warm fluid into the device; and

(g) sealing the gap in the peripheral seal of the device.