TRISTATE ELECTROCHROMIC DEVICE

• US 20060023290A1
• Filed: 09/27/2005
• Published: 02/02/2006
• Est. Priority Date: 05/21/2004
• Status: Active Grant

• Current Assignee: Gentex Corporation
• Original Assignee: Gentex Corporation
• Inventors: Guarr, Thomas F., Giri, Punam
• Granted Patent: US 7,075,697 B2
• Time in Patent Office: Days
• 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
• CPC Class Codes: G02F 1/163 Operation of electrochromic cells, e.g. electrodeposition cells; Circuit arrangements therefor
• CPC Class Codes: G02F 2203/11 involving infrared radiation

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 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

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, in a first state, the total percent of solar radiation transmitted through the device in the visible region is greater than approximately 70 percent and the total percent of solar radiation transmitted through the device in the near-infrared region is greater than approximately 45 percent;

wherein, in a second state, the total percent of solar radiation transmitted through the device in the visible region is less than approximately 15 percent and the total percent of solar radiation transmitted through the device in the near-infrared region is greater than approximately 40 percent; and

wherein, in a third state, the total percent of solar radiation transmitted through the device in the visible region is less than approximately 15 percent and the total percent of solar radiation transmitted through the device in the near-infrared region is less than approximately 25 percent.

2. The electrochromic device according to claim 1, wherein a first cathodic material comprises a viologen.

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

4. The electrochromic device according to claim 1, wherein a second anodic material comprises a dithiazine.

5. The electrochromic device 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.

6. The electrochromic device according to claim 1, wherein the concentration of at least one of the at least one anodic material and at least one of the at least one cathodic material ranges from approximately 2 mM to approximately 100 mM.

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

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

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

10. The electrochromic device according to claim 1, wherein the device is an electrochromic window.

11. An 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

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, in a first state, the total percent of solar radiation transmitted through the device in the visible region is greater than approximately 65 percent and the total percent of solar radiation transmitted through the device in the near-infrared region is greater than approximately 45 percent;

wherein, in a second state, the total percent of solar radiation transmitted through the device in the visible region is greater than approximately 40 percent and the total percent of solar radiation transmitted through the device in the near-infrared region is less than approximately 25 percent; and

wherein, in a third state, the total percent of solar radiation transmitted through the device in the visible region is less than approximately 15 percent and the total percent of solar radiation transmitted through the device in the near-infrared region is less than approximately 15 percent.

12. The electrochromic device according to claim 11, wherein a first cathodic material comprises a ferrocinium species.

13. The electrochromic device according to claim 11, wherein a second cathodic material comprises a viologen.

14. The electrochromic device according to claim 11, wherein a first anodic material comprises a dithiazine.

15. The electrochromic device according to claim 11, wherein a first cathodic material comprises a ferrocinium species, a second cathodic material comprises a viologen, and a first anodic material comprises a dithiazine.

16. The electrochromic device according to claim 11, wherein the concentration of at least one of the at least one anodic material and at least one of the at least one cathodic material ranges from approximately 2 mM to approximately 100 mM.

17. The electrochromic device according to claim 11, wherein the electrochromic medium further comprises a cross-linked polymer matrix.

18. The electrochromic device according to claim 11, wherein the electrochromic medium further comprises a free-standing gel.

19. The electrochromic device according to claim 11, wherein the electrochromic medium further comprises a substantially non-weeping gel.

20. The electrochromic device according to claim 11, wherein the device is an electrochromic window.

21. An electrochromic device, comprising:

means for absorbing less than 60% of both near-infrared and visible radiation in a first state;

means for absorbing greater than 75% of either near-infrared or visible radiation in a second state; and

means for absorbing greater than 75% of both near-infrared and visible radiation in a third state.