Oxidation process for interconnects and end plates
AssigneeBloom Energy Corporation
InventorsSanjiv Kapoor, Michael Gasda, Virginia Osterman, Ken Bauhof
Life of this patent
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Abstract
Methods and systems for oxidizing an interconnect for a fuel cell stack include introducing at least one interconnect to an oxidizing gas containing water vapor, the oxidizing gas being at least substantially free of nitrogen, and oxidizing the at least one interconnect in the presence of the oxidizing gas at an elevated temperature. The oxidation may be performed at a sub-atmospheric pressure. The oxidation of the interconnect may be a controlled oxidation that is performed prior to incorporating the interconnect into a fuel cell stack.
Claims18
A method for oxidizing metal interconnect for a fuel cell stack, comprising:
- introducing at least one metal interconnect to an oxidizing gas comprising water vapor, the oxidizing gas being at least substantially free of nitrogen;
- and
- oxidizing the at least one metal interconnect in the presence of the oxidizing gas at elevated temperature, wherein the oxidation is performed at a sub-atmospheric pressure that is between about 100 and about 700 Torr, and
- incorporating the at least one metal interconnect into a solid oxide fuel cell stack following the step of oxidizing.
A method for oxidizing metal for a fuel cell stack, comprising:
- introducing at least one metal interconnect to an oxidizing gas comprising water vapor, the oxidizing gas being at least substantially free of nitrogen;
- and
- oxidizing the at least one metal interconnect in the presence of the oxidizing gas at elevated temperature at a sub-atmospheric pressure that is between about 100 and about 700 Torr, wherein the oxidation is performed in a processing chamber, the method further comprising:
- evacuating the processing chamber to remove nitrogen from the chamber prior to oxidizing the at least one interconnect, and
- incorporating the at least one metal interconnect into a solid oxide fuel cell stack following the step of oxidizing.
A method for oxidizing metal interconnect for a fuel cell stack, comprising:
- introducing at least one metal interconnect to an oxidizing gas comprising water vapor, the oxidizing gas being at least substantially free of nitrogen;
- and
- oxidizing the at least one metal interconnect in the presence of the oxidizing gas at elevated temperature at a sub-atmospheric pressure that is between about 100 and about 700 Torr, and
- incorporating the at least one metal interconnect into a solid oxide fuel cell stack following the step of oxidizing,
- wherein:
- the at least one metal interconnect comprises a chromium-iron alloy comprising 4-6 wt % iron and 94-96 wt % chromium;
- the at least one metal interconnect is made by powder metallurgy and sintering;
- and
- the step of oxidizing is performed for a period sufficient to at least partially fill pores in the at least one metal interconnect with oxide material.
Dependencies are inferred from the claim text.