Cerium-modified doped strontium titanate compositions for solid oxide fuel cell anodes and electrodes for other electrochemical devices
AssigneeBattelle Memorial Institute
InventorsOlga A. Marina, Jeffry W. Stevenson
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Abstract
The present invention provides novel compositions that find advantageous use in making electrodes for electrochemical cells and electrochemical devices such as solid oxide fuel cells, electrolyzers, sensors, pumps and the like, the compositions comprising cerium-modified doped strontium titanate. The invention also provides novel methods for making and using anode material compositions and solid oxide fuel cells and solid oxide fuel cell assemblies having anodes comprising the compositions.
Claims104
An integral solid oxide fuel cell for electrochemically reacting a fuel gas with an oxidant gas at an elevated temperature to produce a DC output voltage, said solid oxide fuel cell comprising:
- a layer of ceramic ion conducting electrolyte defining first and second opposing surfaces;
- a conductive anode layer in contact with the first surface of said electrolyte layer;
- and
- a conductive cathode layer in contact with the second surface of said electrolyte layer;
- wherein said electrolyte layer is disposed between said anode layer and said cathode layer;
- wherein said conductive anode layer comprises a cerium-modified doped strontium titanate material;
- wherein the cerium-modified doped strontium titanate material comprises an A-site dopant selected from the group consisting of lanthanum, scandium, yttrium and combinations thereof;
- and
- wherein cerium is present in the cerium-modified doped strontium titanate material in an amount of at least about 2 atomic percent.
A solid oxide fuel cell assembly for electrochemically reacting a fuel gas with a flowing oxidant gas at an elevated temperature to produce a DC output voltage, said assembly comprising a plurality of integral fuel cell units, each unit comprising a layer of ceramic ion conducting electrolyte disposed between and in contact with a conductive anode layer and a conductive cathode layer;
- wherein the anode layer of at least one of said fuel cells comprises a cerium-modified doped strontium titanate composition in contact with the electrolyte, wherein the cerium-modified doped strontium titanate material comprises an A-site dopant selected from the group consisting of lanthanum, scandium, yttrium and combinations thereof;
- and wherein cerium is present in the cerium-modified doped strontium titanate material in an amount of at least about 2 atomic percent.
An anode for a solid oxide fuel cell, the anode comprising a cerium-modified doped strontium titanate material, the material including an A-site dopant selected from the group consisting of lanthanum, scandium, yttrium and combinations thereof;
- and wherein cerium is present in the cerium-modified doped strontium titanate material in an amount of at least about 2 atomic percent.
An electrode for an electrochemical device, the electrode comprising a cerium-modified doped strontium titanate material, the material including an A-site dopant selected from the group consisting of lanthanum, scandium, yttrium and combinations thereof;
- and wherein cerium is present in the cerium-modified doped strontium titanate material in an amount of at least about 2 atomic percent.
A method for making a cerium-modified doped strontium titanate solid oxide fuel cell anode comprising:
- providing a cerium-modified strontium titanate material;
- and
- forming the cerium-modified strontium titanate material into an anode for a solid oxide fuel cell.
A method for producing electrical energy, comprising:
- providing a solid oxide fuel cell, the solid oxide fuel cell including a layer of ceramic ion conducting electrolyte defining first and second opposing surfaces;
- a conductive anode layer in contact with the first surface of said electrolyte layer;
- and a conductive cathode layer in contact with the second surface of said electrolyte layer;
- wherein said electrolyte layer is disposed between said anode layer and said cathode layer;
- wherein said conductive anode layer comprises a cerium-modified doped strontium titanate material;
- wherein the cerium-modified doped strontium titanate material comprises an A-site dopant selected from the group consisting of lanthanum, scandium, yttrium and combinations thereof;
- and wherein cerium is present in the cerium-modified doped strontium titanate material in an amount of at least about 2 atomic percent;
- causing air or other oxidizing gas to flow in contact with the cathode layer;
- and
- causing a fuel gas to intermittently flow in contact with the anode layer to provide electrical energy;
- wherein the intermittent flow of the fuel gas includes periods of fuel flow separated by at least one period during which the flow of the fuel is interrupted and the anode layer is exposed to an oxidizing atmosphere.
A method for producing electrical energy, comprising:
- providing a solid oxide fuel cell, the solid oxide fuel cell including a layer of ceramic ion conducting electrolyte defining first and second opposing surfaces;
- a conductive anode layer in contact with the first surface of said electrolyte layer;
- and a conductive cathode layer in contact with the second surface of said electrolyte layer;
- wherein said electrolyte layer is disposed between said anode layer and said cathode layer;
- wherein said conductive anode layer comprises a cerium-modified doped strontium titanate material;
- wherein the cerium-modified doped strontium titanate material comprises an A-site dopant selected from the group consisting of lanthanum, scandium, yttrium and combinations thereof;
- and wherein cerium is present in the cerium-modified doped strontium titanate material in an amount of at least about 2 atomic percent;
- causing air or other oxidizing gas to flow in contact with the cathode layer;
- and
- causing a fuel gas to flow in contact with the anode layer to provide electrical energy;
- wherein the fuel includes a carbon-containing gas;
- and
- wherein the fuel cell produces electrical energy for a period of at least one hour.
A method for producing electrical energy, comprising:
- providing a solid oxide fuel cell, the solid oxide fuel cell including a layer of ceramic ion conducting electrolyte defining first and second opposing surfaces;
- a conductive anode layer in contact with the first surface of said electrolyte layer;
- and a conductive cathode layer in contact with the second surface of said electrolyte layer;
- wherein said electrolyte layer is disposed between said anode layer and said cathode layer;
- wherein said conductive anode layer comprises a cerium-modified doped strontium titanate material;
- wherein the cerium-modified doped strontium titanate material comprises an A-site dopant selected from the group consisting of lanthanum, scandium, yttrium and combinations thereof;
- and wherein cerium is present in the cerium-modified doped strontium titanate material in an amount of at least about 2 atomic percent;
- causing air or other oxidizing gas to flow in contact with the cathode layer;
- and
- causing a fuel gas to flow in contact with the anode layer to provide electrical energy;
- wherein the fuel is a sulfur-bearing fuel;
- and
- wherein the fuel cell produces electrical energy for a period of at least one hour.
Dependencies are inferred from the claim text.