Controllable electrochromic indicator device with ionic conducting intermediate layer and non-polarizable electrodes

• US 3,971,624 A
• Filed: 05/06/1975
• Issued: 07/27/1976
• Est. Priority Date: 06/12/1974
• Status: Expired due to Term

• Current Assignee: BBC Brown Boveri & Company Limited (ABB Limited)
• Original Assignee: BBC Brown Boveri & Company Limited (ABB Limited)
• Inventors: Zeller, Hans-Rudolf, Schuler, Claus, Lehmann, Fritz, Bruesch, Peter
• Primary Examiner(s): Sikes, William L.
• Application Number:
  US05/575,008
• Time in Patent Office: 448 Days
• Field of Search: 350/160
• US Class Current: 359/267
• CPC Class Codes: G02F 1/1523 comprising inorganic material
• CPC Class Codes: G02F 1/1525 characterised by a particular ion transporting layer, e.g. electrolyte

Abstract

A controllable electrochromic indicator device is disclosed which includes two electrodes, an electrochromic layer and an adjacent charge-carrier-transmitting insulator layer situated between the two electrodes and at least one of the electrodes being deposited on a supporting plate and at least one of the electrodes being transparent. The charge carrier transmitting insulator layer is a good ion conductor and functions to almost completely block the flow of electrons. At least one of the electrodes is non-polarizable and is disposed in direct contact with the ion conductor.

Claims

1. A controllable electrochomic indicator device comprising:

two electrodes,

an electrochromic layer and an adjacent charge-carrier-transmitting insulator layer situated between the two electrodes,

at least one of the electrodes being deposited on a supporting plate and at least one of the electrodes being transparent,

the charge carrier transmitting insulator layer being a good ion conductor and functioning to almost completely block the flow of electrons, and

at least one of the electrodes being non-polarizable and disposed in contact with the ion conductor.

2. A controllable electrochomic indicator device as in claim 1 wherein the specific ionic conductivity of the ion conductor lies approximately between 10^-1 and 10^-10 Ω

^-1 cm^-1 and its film thickness can be as much as 20 μ

.

3. A controllable electrochromic indicator device as in claim 1 wherein the ion conductor is a crystalline substance.

4. A controllable electrochromic indicator device as in claim 3 wherein the crystalline substance is silver iodide.

5. A controllable electrochromic indicator device as in claim 3 wherein the crystal is Li₂ SO₄, CuBr, CuI, Rb₄ AgI₅ or β

-alumina.

6. A controllable electrochromic indicator device as in claim 1 wherein the ion conductor is an amorphous or polycrystalline substance.

7. A controllable electrochromic indicator device as in claim 6 characterized by the fact that the amorphous substance is a SiO₂ --B₂ O₃ glass.

8. A controllable electrochromic indicator device as in claim 7 wherein the SiO₂ --B₂ O₃ glass has approximately the mole percent composition 25Li₂ O + 50SiO₂ + 25B₂ O₃.

9. A controllable electrochromic indicator device as in claim 7 wherein the SiO₂ --B₂ O₃ glass has approximately the mole percent composition 35Li₂ O + 28Li₂ SO₄ + 7(LiCl)₂ + 4SiO₂ + 26B₂ O₃.

10. A controllable electrochromic indicator device as in claim 1 wherein the ion conductor is an ion-conducting polymer.

11. A controllable electrochromic indicator device as in claim 10 wherein the polymer is perflouorated sulfonic acid.

12. A controllable electrochromic indicator device as in claim 1 wherein the electrochromic layer comprises oxides and oxide mixtures of the metals manganese, molybdenum, niobium, palladium, platinum, rhenium, titanium, vanadium or tungsten.

13. A controllable electrochromic indicator device as in claim 12 wherein the oxides and oxide mixtures comprise WO₃, MoO₃, and/or WO₃ /MoO₃.

14. A controllable electrochromic indicator device as in claim 1 wherein the non-polarizable electrode is a mixed ion-electron conductor.

15. A controllable electrochromic indicator device as in claim 14 wherein the mixed ion-electron conductor is a tungsten and/or molybdenum bronze.

16. A controllable electrochromic indicator device as in claim 15 wherein the bronze has the composition MxY, where 0 <

x <

1 and M = Li, Na, K, Rb, Cs, Be, Mg, Ca, Ba, Sr, H, NH₄, Cu or Ag while Y = WO₃, MoO₃ or WO₃ /MoO₃.

17. A controllable electrochromic indicator device as in claim 14 wherein the mixed ion-electron conductor is an electrochromic layer.

18. A controllable electrochromic indicator device as in claim 16 wherein the non-polarizable electrode is Ag_x Y or Li_x Y, where Y = WO₃, MoO₃, WO₃ /MoO₃ and 0 <

x <

1.

19. A controllable electrochromic indicator device as in claim 18 wherein the proportion x of Ag or Li in the non-polarizable electrode is between 0.7 and 0.85.

20. A controllable electrochromic indicator device as in claim 18 wherein the proportion x of Ag or Li in the electrochromic layer is between 0 and 0.3.

21. A controllable electrochromic indicator device as in claim 17 wherein the two electrochromic layers are similar.

22. A controllable electrochromic indicator device as in claim 14 wherein the mixed ion-electron conductor contains hydrogen-bearing platinum and/or palladium.

23. A controllable electrochromic indicator device as in claim 14 wherein the mixed ion-electron conductor contains graphite-alkali metal alloys or selenides and sulfides of silver and tungsten.

24. A controllable electrochromic indicator device as in claim 1 wherein the non-polarizable electrode is coated at least partially on the rear surface with a metallic contact film.