Low vapor pressure solvent for electrochromic devices

• US 20050200933A1
• Filed: 10/27/2004
• Published: 09/15/2005
• Est. Priority Date: 03/12/2004
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Weidner, Arthur P.
• Granted Patent: US 8,988,757 B2
• Time in Patent Office: Days
• US Class Current: 359/265
• CPC Class Codes: B64C 1/1484 Windows B64C1/1492 takes precedence
• CPC Class Codes: B64D 2011/0061 Windows displaying outside view, artificially generated
• CPC Class Codes: G02F 1/1506 caused by electrodeposition, e.g. electrolytic deposition of an inorganic material on or close to an electrode
• CPC Class Codes: G02F 1/1516 comprising organic material
• CPC Class Codes: G02F 1/15165 Polymers
• CPC Class Codes: G02F 1/1525 characterised by a particular ion transporting layer, e.g. electrolyte
• CPC Class Codes: G02F 1/153 Constructional details
• CPC Class Codes: G02F 1/1533 structural features not otherwise provided for
• CPC Class Codes: G02F 1/163 Operation of electrochromic cells, e.g. electrodeposition cells; Circuit arrangements therefor
• CPC Class Codes: G02F 2001/164 the electrolyte is made of polymers

Abstract

The present invention provides an electrolyte for electrochromic devices, the substance comprising γ-butyrolactone (gamma-butyrolactone or GBL). The electrolyte may include polymethylmethacrylate. The electrolyte may further include a salt, such as a salt that includes lithium perchlorate or trifluorosulfonimide. In accordance with further aspects to the invention, the electrolyte may include propylene carbonate.

Claims

1. An electrolyte for transmitting ions for an electrochromic device, the electrolyte comprising:

a first solvent including gamma-butyrolactone; and

a salt.

2. The electrolyte of claim 1, wherein the salt includes at least one of a lithium perchlorate and a trifluorosulfonimide.

3. The electrolyte of claim 1, further comprising a polymer matrix.

4. The electrolyte of claim 3, wherein the polymer matrix includes polymethylmethacrylate.

5. The electrolyte of claim 1, further comprising a gelling agent.

6. The electrolyte of claim 1, further comprising a second solvent.

7. The electrolyte of claim 6, wherein at least one the first and second solvents includes propylene carbonate.

8. An electrolyte for transmitting ions for an electrochromic device, the electrolyte comprising:

gamma-butyrolactone;

propylene carbonate;

polymethylmethacrylate; and

a salt.

9. The electrolyte of claim 8, wherein the salt includes one of lithium perchlorate and trifluorosulfonimide.

10. An electrochromic device comprising:

a first electrode sheet, the first electrode sheet being substantially transparent;

a second electrode sheet, the second electrode sheet being substantially transparent;

an electrochromic polymer layer disposed between the first electrode sheet and the second electrode sheet; and

a gel electrolyte disposed between the electrochromic polymer layer and one of the first electrode sheet and the second electrode sheet, the gel electrolyte including gamma-butyrolactone and a salt.

11. The electrochromic device of claim 10, wherein at least one of the first and second electrode sheets comprises a tinted electrode sheet.

12. The electrochromic device of claim 10, wherein the salt includes at least one of lithium perchlorate, lithium trifluorosulfonimide, and combinations thereof.

13. The electrochromic device of claim 10, wherein the gel electrolyte includes at least one of polymethylmethacrylate and propylene carbonate.

14. The electrochromic device of claim 10, further comprising a frame adapted to hold the first electrode sheet, the second electrode sheet, the electrochromic polymer layer, and the gel electrolyte as a portion of a window assembly in an aircraft fuselage.

15. The electrochromic device of claim 10, further comprising a frame adapted to hold the first electrode sheet, the second electrode sheet, the electrochromic polymer layer, and the gel electrolyte as a window shade for an aircraft window.

16. A method for conducting ions in an electrochromic device comprising:

disassociating a salt into at least one component ion in an electrolyte in an electrochromic device, the electrolyte including gamma-butyrolactone; and

conducting the at least one component ion in the electrolyte by applying an electric field.

17. The method of claim 16, wherein disassociating a salt includes disassociating at least one of a lithium perchlorate and a lithium trifluorosulfonimide.

18. The method of claim 16, wherein disassociating a salt into at least one component ion in an electrolyte includes disassociating a salt into at least one component ion in an electrolyte, wherein the electrolyte includes at least one of polymethylmethacrylate and propylene carbonate.

19. The method of claim 16, wherein conducting the at least one component ion in the electrolyte by applying an electric field includes conducting the at least one component ion in the electrolyte by applying an electric field between a first sheet electrode and a second sheet electrode.

20. The electrochromic device of claim 19, wherein at least one of the first and second sheet electrodes comprises a tinted sheet electrode.

21. A method for providing an extended life for an electrochromic device, comprising:

disposing gamma-butyrolactone in an electrolyte in the electrochromic device.

22. The method of claim 21, further comprising operating the electrochromic device.

23. The method of claim 22, wherein operating the electrochromic device includes disassociating a salt into at least one component ion in the electrolyte containing gamma-butyrolactone.

24. The method of claim 22, wherein operating the electrochromic device includes conducting the at least one component ion in the electrolyte by applying an electric field between a first sheet electrode and a second sheet electrode.

25. An electrochromic device, comprising:

an electrolyte having at least one salt dissolved in an effective amount of gamma-butyrolactone.

26. The electrochromic device of claim 25, wherein the effective amount includes from 90% to 60% gamma-butyrolactone by weight, inclusive.

27. The electrochromic device of claim 25, wherein the effective amount includes from 65% to 75% gamma-butyrolactone by weight, inclusive.

28. An electrochromic device comprising:

an electrolyte including gamma-butyrolactone; and

a plurality of pigments of electrochromic material.

29. The electrochromic device of claim 28, further comprising first and second electrode sheets disposed on opposing sides of the electrolyte.

30. The electrochromic device of claim 29, wherein at least one of the first and second electrode sheets comprises a tinted electrode sheet.

31. The electrochromic device of claim 28, further comprising a salt disposed in the electrolyte.

32. The electrochromic device of claim 31, wherein the salt includes at least one of lithium perchlorate, lithium trifluorosulfonimide, and combinations thereof.

33. The electrochromic device of claim 28, wherein the electrolyte includes at least one of polymethylmethacrylate and propylene carbonate.