Durable electrooptic devices comprising ionic liquids

• US 7,633,669 B2
• Filed: 11/06/2008
• Issued: 12/15/2009
• Est. Priority Date: 06/21/2002
• Status: Active Grant

• Current Assignee: TRIAD National Security, LLC
• Original Assignee: Los Alamos National Security LLC (Government of the United States of America)
• Inventors: Tonazzi, Juan C. L., Agrawal, Anoop, Cronin, John P., Burrell, Anthony K., Warner, Benjamin P., McCleskey, T. Mark
• Primary Examiner(s): Ben; Loha
• Application Number:
  US12/291,381
• Publication Number:
  US 20090103162A1
• Time in Patent Office: 404 Days
• Field of Search: 359/265, 359/267, 359/252, 359/254, 359270-275, 428/426, 428/432, 428/522, 428/702, 264/1.31, 264/1.38, 264/1.7, 264/571, 429/213, 205/58, 362/540
• US Class Current: 359/270
• CPC Class Codes: B60R 1/088 using a cell of electrically changeable optical characteristic, e.g. liquid-crystal or electrochromic mirrors
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: C09K 2211/1029 containing one nitrogen atom as the heteroatom
• CPC Class Codes: C09K 9/02 Organic tenebrescent materials
• CPC Class Codes: G02F 1/1503 caused by oxidation-reduction reactions in organic liquid solutions, e.g. viologen solutions
• CPC Class Codes: G02F 1/155 Electrodes
• CPC Class Codes: G02F 1/157 Structural association of cells with optical devices, e.g. reflectors or illuminating devices
• CPC Class Codes: G02F 2202/022 polymeric
• CPC Class Codes: G02F 2202/36 Micro- or nanomaterials

Abstract

Electrolyte solutions for electrochromic devices such as rear view mirrors and displays with low leakage currents are prepared using inexpensive, low conductivity conductors. Preferred electrolytes include bifunctional redox dyes and molten salt solvents 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⁻). Electroluminescent, electrochromic and photoelectrochromic devices with nanostructured electrodes include ionic liquids with bifunctional redox dyes. Some of the electrolyte solutions color to red when devices employing the solutions are powered, leading to red or neutral electrooptic devices.

Claims

1. An electrochromic automotive rear-view mirror with an electrolyte comprising an ionic liquid that has at least one of a coloration speed of less than or equal to 10 seconds and a bleach speed of less than or equal to 10 seconds, wherein said mirror is self-erasing.

2. An electrochromic automotive rear-view mirror with an electrolyte comprising an ionic liquid that has at least one of a coloration speed of less than or equal to 10 seconds and a bleach speed of less than or equal to 10 seconds, wherein said electrolyte comprises a bifunctional dye.

3. An electrochromic automotive rear-view mirror with an electrolyte comprising an ionic liquid that has at least one of a coloration speed of less than or equal to 10 seconds and a bleach speed of less than or equal to 10 seconds, wherein said mirror darkens to a neutral color when the electrochromic mirror is powered.

4. An electrochromic automotive exterior rear-view mirror with an electrolyte comprising an ionic liquid that has at least one of a coloration speed of less than or equal to 30 seconds and a bleach speed of less than or equal to 30 seconds, wherein said mirror is self-erasing.

5. The electrochromic mirror of claim 4, wherein said electrolyte comprises a bifunctional dye.

6. An electrochromic mirror of claim 4, wherein said mirror darkens to a neutral color when the electrochromic mirror is powered.