Method and apparatus for reducing reactant crossover in an electrochemical fuel cell
AssigneeBallard Power Systems Inc.
InventorsDavid P. Wilkinson, Mark C. Johnson, Kevin M. Colbow, Stephen A. Campbell
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Abstract
In an electrochemical fuel cell, a sufficient quantity of catalyst, effective for promoting the reaction of reactant supplied to an electrode, is disposed within the volume of the electrode so that a reactant introduced at a first major surface of the electrode is substantially completely reacted upon contacting the second major surface. Crossover of reactant from one electrode to the other electrode through the electrolyte in an electrochemical fuel cell is thereby reduced.
Claims24
An electrochemical fuel cell comprising:
- (a) a first electrode, said first electrode having first and second oppositely facing major surfaces, said first electrode comprising at least one layer of porous material and a sufficient quantity of catalyst disposed within the volume of said electrode between said major surfaces so that a reactant in a fluid introduced to said first major surface of said first electrode is substantially completely reacted upon contacting said second major surface of said first electrode;
- (b) a second electrode;
- (c) an electrolyte interposed between said second major surface of said first electrode and said second electrode;
- wherein said at least one layer of porous material comprises a plurality of stacked layers.
An electrochemical fuel cell comprising:
- (a) a first electrode, said first electrode having first and second oppositely facing major surfaces, said first electrode comprising (1) at least one layer of porous electrically conductive material comprising a proton conductor and (2) a sufficient quantity of catalyst disposed within the volume of said electrode between said major surfaces so that a reactant in a fluid introduced to said first major surface of said first electrode is substantially completely reacted upon contacting said second major surface of said first electrode;
- (b) a second electrode;
- (c) an electrolyte interposed between said second major surface of said first electrode and said second electrode, said electrolyte comprising an ion-exchange membrane;
- wherein said at least one layer of porous electrically conductive material comprises carbon fiber paper.
An electrochemical fuel cell comprising:
- (a) a first electrode, said first electrode having first and second oppositely facing major surfaces, said first electrode comprising (1) at least one layer of porous electrically conductive material comprising a proton conductor and (2) a sufficient quantity of catalyst disposed within the volume of said electrode between said major surfaces so that a reactant in a fluid introduced to said first major surface of said first electrode is substantially completely reacted upon contacting said second major surface of said first electrode;
- (b) a second electrode;
- (c) an electrolyte interposed between said second major surface of said first electrode and said second electrode, said electrolyte comprising an ion-exchange membrane;
- wherein said at least one layer of porous electrically conductive material comprises carbon cloth.
An electrochemical fuel cell comprising:
- (a) a first electrode, said first electrode having first and second oppositely facing major surfaces, said first electrode comprising (1) at least one layer of porous electrically conductive material comprising a proton conductor and (2) a sufficient quantity of catalyst disposed within the volume of said electrode between said major surfaces so that a reactant in a liquid introduced to said first major surface of said first electrode is substantially completely reacted upon contacting said second major surface of said first electrode;
- (b) a second electrode;
- (c) an electrolyte interposed between said second major surface of said first electrode and said second electrode, said electrolyte comprising an ion-exchange
- wherein said first electrode is an anode and said reactant comprises an alcohol.
An electrode for an electrochemical fuel cell, said electrode having first and second oppositely facing major surfaces, said electrode comprising:
- (a) at least one layer of porous material;
- (b) a sufficient quantity of catalyst disposed within the volume of said electrode between said major surfaces so that a reactant in a fluid introduced to said first major surface of said first electrode is substantially completely reacted upon contacting said second major surface of said electrode;
- wherein said at least one layer of porous material comprises a plurality of stacked layers.
An electrode for an electrochemical fuel cell comprising an electrolyte comprising an ion-exchange membrane, said electrode having first and second oppositely facing major surfaces, said electrode comprising:
- (a) at least one layer of porous electrically conductive material comprising a proton conductor;
- (b) a sufficient quantity of catalyst disposed within the volume of said electrode between said major surfaces so that a reactant in a fluid introduced to said first major surface of said electrode is substantially completely reacted upon contacting said second major surface of said electrode;
- wherein said at least one layer of porous electrically conductive material comprises carbon fiber paper.
An electrode for an electrochemical fuel cell comprising an electrolyte comprising an ion-exchange membrane, said electrode having first and second oppositely facing major surfaces, said electrode comprising:
- (a) at least one layer of porous electrically conductive material comprising a proton conductor;
- (b) a sufficient quantity of catalyst disposed within the volume of said electrode between said major surfaces so that a reactant in a fluid introduced to said first major surface of said electrode is substantially completely reacted upon contacting said second major surface of said electrode;
- wherein said at least one layer of porous electrically conductive material comprises carbon cloth.
An electrode for an electrochemical fuel cell comprising an electrolyte comprising an ion-exchange membrane, said electrode having first and second oppositely facing major surfaces, said electrode comprising:
- (a) at least one layer of porous electrically conductive material comprising a proton conductor;
- (b) a sufficient quantity of catalyst disposed within the volume of said electrode between said major surfaces so that a reactant in a liquid introduced to said first major surface of said electrode is substantially completely reacted upon contacting said second major surface of said electrode;
- wherein said electrode is an anode and said reactant comprises an alcohol.
A method of reducing reactant crossover from a first electrode of an electrochemical fuel cell to a second electrode thereof, said first electrode having first and second oppositely facing major surfaces, said reactant introduced in a fluid at said first major surface, said first electrode comprising at least one layer of porous material and a catalyst, said fuel cell further comprising an electrolyte interposed between said second major surface of said first electrode and said second electrode, the method comprising:
- disposing a sufficient quantity of said catalyst within the volume of said first electrode between said major surfaces such that said reactant is substantially completely reacted upon contacting said second major surface;
- wherein said at least one layer of porous material comprises a plurality of stacked layers.
A method of reducing reactant crossover from a first electrode of an electrochemical fuel cell to a second electrode thereof, said first electrode having first and second oppositely facing major surfaces, said reactant introduced in a fluid at said first major surface, said first electrode comprising (a) at least one layer of porous electrically conductive material comprising a proton conductor and (b) a catalyst, said fuel cell further comprising an electrolyte interposed between said second major surface of said first electrode and said second electrode, said electrolyte comprising an ion-exchange membrane, the method comprising:
- disposing a sufficient quantity of said catalyst within the volume of said first electrode between said major surfaces such that said reactant is substantially completely reacted upon contacting said second major surface;
- wherein said at least one layer of porous electrically conductive material comprises carbon fiber paper.
A method of reducing reactant crossover from a first electrode of an electrochemical fuel cell to a second electrode thereof, said first electrode having first and second oppositely facing major surfaces, said reactant introduced in a fluid at said first major surface, said first electrode comprising (a) at least one layer of porous electrically conductive material comprising a proton conductor and (b) a catalyst, said fuel cell further comprising an electrolyte interposed between said second major surface of said first electrode and said second electrode, said electrolyte comprising an ion-exchange membrane, the method comprising:
- disposing a sufficient quantity of said catalyst within the volume of said first electrode between said major surfaces such that said reactant is substantially completely reacted upon contacting said second major surface;
- wherein said at least one layer of porous electrically conductive material comprises carbon cloth.
A method of reducing reactant crossover from a first electrode of an electrochemical fuel cell to a second electrode thereof, said first electrode having first and second oppositely facing major surfaces, said reactant introduced in a liquid at said first major surface, said first electrode comprising (a) at least one layer of porous electrically conductive material comprising a proton conductor and (b) a catalyst, said fuel cell further comprising an electrolyte interposed between said second major surface of said first electrode and said second electrode, said electrolyte comprising an ion-exchange membrane, the method comprising:
- disposing a sufficient quantity of said catalyst within the volume of said first electrode between said major surfaces such that said reactant is substantially completely reacted upon contacting said second major surface;
- wherein said electrode is an anode and said reactant comprises an alcohol.
Dependencies are inferred from the claim text.