Tristate electrochromic device

• US 6,876,479 B1
• Filed: 05/21/2004
• Issued: 04/05/2005
• Est. Priority Date: 05/21/2004
• Status: Active Grant

• Current Assignee: Gentex Corporation
• Original Assignee: Gentex Corporation
• Inventors: Guarr, Thomas F., Giri, Punam
• Primary Examiner(s): Epps, Georgia
• Assistant Examiner(s): Dinh, Jack
• Application Number:
  US10/850,989
• Time in Patent Office: 319 Days
• Field of Search: 359265-275, 345/107, 252/583, 252/600, 544/347, 546/257
• US Class Current: 359/273
• CPC Class Codes: G02F 1/1503 caused by oxidation-reduction reactions in organic liquid solutions, e.g. viologen solutions
• CPC Class Codes: G02F 1/153 Constructional details

Abstract

An electrochromic medium for use in a tristate electrochromic device, comprising: (a) at least one solvent; (b) at least one anodic material; (c) at least one cathodic material, wherein both of the anodic and cathodic materials are electroactive and at least one of the anodic and cathodic materials is electrochromic; (d) wherein, in a first state, the electrochromic medium exhibits a maximum light transmission; (e) wherein, in a second state, variable attenuation occurs to a significant extent in one of visible radiation or near-infrared radiation without significant attenuation in the other; and (f) wherein, in a third state, variable attenuation occurs to a significant extent in the other spectral region.

Claims

1. An electrochromic medium for use in a tristate electrochromic device, comprising:

at least one solvent;

at least one anodic material;

at least one cathodic material, wherein both of the anodic and cathodic materials are electroactive and at least one of the anodic and cathodic materials is electrochromic;

wherein, in a first state, the electrochromic medium exhibits a maximum light transmission;

wherein, in a second state, variable attenuation occurs to a significant extent in one of visible radiation or near-infrared radiation without significant attenuation in the other; and

wherein, in a third state, variable attenuation occurs to a significant extent in the other spectral region.

2. The electrochromic medium according to claim 1, wherein a first cathodic material comprises a ferrocinium species.

3. The electrochromic medium according to claim 1, wherein a second cathodic material comprises a viologen.

4. The electrochromic medium according to claim 1, wherein a first anodic material comprises a dithiazine.

5. The electrochromic medium according to claim 1, wherein a first cathodic material comprises a ferrocinium species, a second cathodic material comprises a viologen, and a first anodic material comprises a dithiazine.

6. The electrochromic medium according to claim 1, wherein a first cathodic material comprises a viologen.

7. The electrochromic medium according to claim 1, wherein a first anodic material comprises a substituted phenazine.

8. The electrochromic medium according to claim 1, wherein a second anodic material comprises a dithiazine.

9. The electrochromic medium according to claim 1, wherein a first anodic material comprises a substituted phenazine, a second anodic material comprises a dithiazine, and a first cathodic material comprises a viologen.

10. The electrochromic medium according to claim 1, wherein the concentration of a first cathodic material ranges from approximately 1 mM to approximately 500 mM.

11. The electrochromic medium according to claim 1, wherein the concentration of a first cathodic material ranges from approximately 2 mM to approximately 100 mM.

12. The electrochromic medium according to claim 1, wherein the concentration of a second cathodic material ranges from approximately 1 mM to approximately 500 mM.

13. The electrochromic medium according to claim 1, wherein the concentration of a second cathodic material ranges from approximately 2 mM to approximately 100 mM.

14. The electrochromic medium according to claim 1, wherein the concentration of a first anodic material ranges from approximately 1 mM to approximately 500 mM.

15. The electrochromic medium according to claim 1, wherein the concentration of a first anodic material ranges from approximately 2 mM to approximately 100 mM.

16. The electrochromic medium according to claim 1, wherein the concentration of a second anodic material ranges from approximately 1 mM to approximately 500 mM.

17. The electrochromic medium according to claim 1, wherein the concentration of a second anodic material ranges from approximately 2 mM to approximately 100 mM.

18. The electrochromic medium according to claim 1, wherein the electrochromic medium further comprises a cross-linked polymer matrix.

19. The electrochromic medium according to claim 1, wherein the electrochromic medium further comprises a free-standing gel.

20. The electrochromic medium according to claim 1, wherein the electrochromic medium further comprises a substantially non-weeping gel.

21. A tristate electrochromic device, comprising:

a first substantially transparent substrate having an electrically conductive material associated therewith;

a second substrate having an electrically conductive material associated therewith; and

the electrochromic medium according to claim 1 contained within a chamber positioned between the first and second substrates.

22. The electrochromic device according to claim 21, wherein the device is an electrochromic window.

23. The electrochromic device according to claim 21, wherein the second substrate is coated with a reflective material.

24. The electrochromic device according to claim 23, wherein the device is an electrochromic mirror.

25. A tristate electrochromic device, comprising:

at least one substantially transparent substrate having an electrically conductive material associated therewith; and

an electrochromic medium which comprises;

at least one solvent;

at least one anodic material;

at least one cathodic material, wherein both of the anodic and cathodic materials are electroactive and at least one of the anodic and cathodic materials is electrochromic;

wherein, in a first state, the electrochromic medium exhibits a maximum light transmission;

wherein, in a second state, variable attenuation occurs to a significant extent in one of visible radiation or near-infrared radiation without significant attenuation in the other; and

wherein, in a third state, variable attenuation occurs to a significant extent in the other spectral region.

26. A tristate electrochromic device, comprising:

a first substantially transparent substrate having an electrically conductive material associated therewith;

a second substrate having an electrically conductive material associated therewith;

an electrochromic medium contained within a chamber positioned between the first and second substrates which comprises;

at least one solvent;

at least one anodic material;

at least one cathodic material, wherein both of the anodic and cathodic materials are electroactive and at least one of the anodic and cathodic materials is electrochromic;

wherein the tristate device substantially absorbs neither near-infrared, nor visible radiation in a first state;

wherein the tristate device substantially absorbs either near-infrared, or visible radiation in a second state; and

wherein the tristate device substantially absorbs both near-infrared, and visible radiation in a third state.