Patent US441365A successfully refreshed from Google Patents.
Patent US4645307A successfully refreshed from Google Patents.
← Back to Patent Explorer
US4645307A Expired / Lapsed US ⏱️ 0.0 years remaining

Electrochromic device

Assignee: Nissan Motor Co Ltd
•
Filing: 1984-10-19
•
Granted: 1987-02-24
•
Expires: 2004-10-19
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract An electrochromic device having two electrochromic layers respectively formed on oppositely arranged two electrodes and containing an electrolyte such as a solution of an alkali metal salt in an organic solvent which fills up the gap between the two electrodes. The electrochromic layers are formed of an electrochromic material which can alternately and stably exist in three different oxidation states and assumes three different colors in its respective oxidation states such that there is a clear contrast between the color of this material in its normal or intermediate oxidation state and a composite color given by superposition of the color in the highest oxidation state on the color in the lowest oxidation state. Prussian blue is a preferred example of such an electrochromic material, on condition that an adequate amount of water be present in the electrolyte solution or, alternatively, that the Prussian blue layers be pretreated to substitute alkali metal cation for Fe 3+ interstitially existing in the crystal lattice of Prussian blue.

Inventors

  • 👤 Takeshi Miyamoto
  • 👤 Mikio Ura
  • 👤 Shigenori Kazama
  • 👤 Takao Kase
  • 👤 Yoshiko Maeda

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 21:54
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/15; G02F1/1514; G02F1/1523; G02F1/1516; G02F2001/1517

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 199 words
An electrochromic device comprising: a first electrode layer which is transparent; a second electrode layer arranged opposite to and spaced from said first electrode layer; first and second electrochromic layers formed respectively on said first and second electrode layers, said electrochromic layers comprising an electrochromic material which is Prussian blue, said electrochromic layers facing each other and undergoing electrochemical oxidation and reduction in two stages and alternately and stably assuming three different oxidation states, the color of each said electrochromic layer in each oxidation state being different from the colors in the other two oxidation states such that there is a clear contrast between the color in the intermediate oxidation state and a composite color given by superposition of the color of one said electrochromic layer in the highest oxidation state on the color of the other said electrochromic layer in the lowest oxidation state; and an electrolyte which fills up the gap between said first and second electrochromic layers, said electrolyte being a solution of a supporting electrolyte of which the cation is alkali metal ion in an orcanic polar solvent comprising propylene carbonate or acetonitrile and containing from about 0.8 to about 15 wt % of water.
Claim 2
Dependent Claim 199 words
An electrochromic device comprising: a first electrode layer which is transparent; a second electrode layer arranged opposite to and spaced from said first electrode layer; first and second electrochromic layers formed respectively on said first and second electrode layers, said electrochromic layers comprising an electrochromic material which is Prussian blue, said electrochromic layers facing each other and undergoing electrochemical oxidation and reduction in two stages and alternately and stably assuming three different oxidation states, the color of each said electrochromic layer in each oxidation state being different from the colors in the other two oxidation states such that there is a clear contrast between the color in the intermediate oxidation state and a composite color given by superposition of the color of one said electrochromic layer in the highest oxidation state on the color of the other said electrochromic layer in the lowest oxidation state; and an electrolyte which fills up the gap between said first and second electrochromic layers, said electrolyte being a solution of a supporting electrolyte of which the cation is alkali metal ion in an orcanic polar solvent comprising propylene carbonate or acetonitrile and containing from about 0.8 to about 15 wt % of water.
Claim 3
Dependent Claim 25 words
An electrochromic device according to claim 1, wherein said supporting electrolyte is selected from the group consisting of lithium perchlorate, sodium perchlorate and potassium borofluoride.
Claim 4
Dependent Claim 193 words
An electrochromic device produced by a process comprising the steps of: (a) forming a separate transparent electrode layer on each two transparent plates, one of said plates forming a bottom substrate and the other of said plates forming a top substrate; (b) electrodepositing a layer of electrochromic material on each of said transparent electrode layers; (c) separately immersing each of said substrates in an aqueous solution containing alkali metal ions, a counter electrode and a reference electrode: (d) applying a variable voltage to said transparent electrode on each of said immersed substrates and continuously varying the potential at said transparent electrode over a range sufficient to effect ion exchange between said electrochromic material in said immersed substrate and said aqueous solution; (e) removing said substrates from said aqueous solution and arranging them in a manner such that said layers of electrochromic material face each other; (f) assembling said substrates into a blank cell by applying a sealant therebetween so as to form a peripheral seal around said layers of electrochromic material, said peripheral seal including an opening; (g) introducing an organic electrolyte into said cell through said opening; and (h) sealing said opening.
Claim 5
Dependent Claim 193 words
An electrochromic device produced by a process comprising the steps of: (a) forming a separate transparent electrode layer on each two transparent plates, one of said plates forming a bottom substrate and the other of said plates forming a top substrate; (b) electrodepositing a layer of electrochromic material on each of said transparent electrode layers; (c) separately immersing each of said substrates in an aqueous solution containing alkali metal ions, a counter electrode and a reference electrode: (d) applying a variable voltage to said transparent electrode on each of said immersed substrates and continuously varying the potential at said transparent electrode over a range sufficient to effect ion exchange between said electrochromic material in said immersed substrate and said aqueous solution; (e) removing said substrates from said aqueous solution and arranging them in a manner such that said layers of electrochromic material face each other; (f) assembling said substrates into a blank cell by applying a sealant therebetween so as to form a peripheral seal around said layers of electrochromic material, said peripheral seal including an opening; (g) introducing an organic electrolyte into said cell through said opening; and (h) sealing said opening.
Claim 6
Dependent Claim 18 words
An electrochromic device according to claim 3, wherein said electrochromic material comprises Prussian blue or 2,2'-bipyridyl iron complex.
Claim 7
Dependent Claim 19 words
An electrochromic device according to claim 3, wherein said alkali metal ions comprise lithium, sodium, potassium, or rubidium ions.
Claim 8
Dependent Claim 26 words
An electrochromic device according to claim 3, wherein said aqueous solution is a solution of potassium chloride at a concentration of about one mole per liter.
Claim 9
Dependent Claim 24 words
An electrochromic device according to claim 3, wherein said variable voltage applied in step (d) is from about -0.4 V to about +0.5 V.
Claim 10
Dependent Claim 21 words
An electrochromic device according to claim 3, wherein said transparent electrodes are tin dioxide, and said forming step includes vacuum deposition.

References Cited (Backward Citations)

US4348077A Cited
DE3048985A1 Cited
DE3011506A1 Cited
JPS57157219A Cited
JPS57157218A Cited
EP0068635A1 Cited
US4498739A Cited
US4562056A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1990-02-23 1990-08-25 1991-02-24 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1994-02-23 1994-08-25 1995-02-24 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1998-02-23 1998-08-25 1999-02-24 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag