High performance electrochemichromic solutions and devices thereof
AssigneeDonnelly Corporation
InventorsDesaraju V. Varaprasad, Niall R. Lynam, Hamid R. Habibi, Padma Desaraju
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Abstract
The specification discloses electrochemichromic solutions and devices based on the use of solvents comprising at least about 25% 3-hydroxypropionitrile, 3,3'-oxydipropionitrile, 2-acetylbutyrolactone, 2-methylglutaronitrile, 3-methylsulfolane and mixtures thereof. The specification also discloses vacuum backfilling techniques for filling electrochemichromic cells and enhanced UV stability through solvent self-screening.
Claims47
An electrochemichromic cell comprising:
- spaced plates, each having an inwardly facing conductive surface;
- an electrochemichromic solution in said cell, between said spaced plates, said solution comprising:
- solvent;
- a redox chemical pair in solution in said solvent which colors in the presence of an applied voltage and which bleaches to a colorless condition in the absence of an applied voltage;
- said solvent including at least 25% by volume of a solvent selected from the group consisting of:
- 3-hydroxypropionitrile (HPN), 3,3-oxydipropionitrile (ODPN),
- 2-acetylbutyrolactone (ABL), 2-methylglutaronitrile (MGNT), and mixtures thereof.
A method for reducing leakage current in an electrochemichromic cell having spaced plates, each having an inwardly facing conductive surface, and a solution located in said cell between said plates, said solution comprising a redox chemical pair which colors in the presence of an applied voltage and which bleaches to a colorless condition in the absence of an applied voltage said method comprising:
- using a solvent for said redox chemical pair comprising at least 25% by volume of a solvent selected from the group consisting of:
- 3-hydroxypropionitrile (HPN), 3,3'-oxydipropionitrile (ODPN), 2-acetylbutyrolactone (ABL), 2-methylglutaronitrile (MGNT), and mixtures thereof.
A method for filling an electrochemichromic cell having relatively closely spaced plates, each having an inwardly facing conductive surface, said spaced plates being sealed around the periphery by a seal, said peripheral seal enclosing an area of each of said plates;
- said filling method comprising:
- introducing a small gap into said seal of an empty cell;
- placing said cell in a chamber along with a container of an electrochemichromic solution and evacuating said chamber;
- lowering said cell into said container of electrochemichromic solution such that said gap is located under the surface of the electrochemichromic solution wherein said electrochemichromic solution comprises:
- a solvent;
- and
- a redox chemical pair in solution in said solvent which colors in the presence of an applied voltage and which bleaches to a colorless condition in the absence of an applied voltage;
- said solvent having a vapor pressure such that said vapor pressure, expressed in units of millimeters of mercury, multiplied by said area, expressed in units of square centimeters, is less than 5,969;
- exposing said electrochemichromic solution to a source of inert gas of pressure greater than that in said cell to thereby cause said solution to flow into said cell;
- and
- sealing said gap in said peripheral seal of said cell.
A method for filling an electrochemichromic cell having relatively closely spaced plates, each having an inwardly facing conductive surface, said spaced plates being sealed around the perimeter to form a sealed cavity, said filling method comprising:
- introducing a pair of spaced small openings in said cell which open into said sealed cavity of said empty cell;
- placing one of said openings in flow communication with an electrochemichromic solution;
- simultaneously placing the other of said openings in flow communication with a vacuum source whereby said solution is drawn into said cell.
An electrochemichromic cell comprising:
- spaced plates, each having an inwardly facing conductive surface;
- an electrochemichromic solution in said cell, between said spaced plates and solution comprising:
- a solvent;
- a redox chemical pair in solution in said solvent which colors in the presence of an applied voltage and which bleaches to a colorless condition in the absence of an applied voltage;
- said solvent including at least 25% 3-methylsulfolane (MS).
A method for reducing leakage current in an electrochemichromic cell having spaced plates, each having an inwardly facing conductive surface, and a solution located in said cell between said plates, said solution comprising a redox chemical pair which colors in the presence of an applied voltage and which bleaches to a colorless condition in the absence of an applied voltage, said method comprising:
- using a solvent for said redox chemical pair comprising at least 25% by volume of 3-methylsulfolane (MS).
Dependencies are inferred from the claim text.