Method of manufacturing a fuel cell stack having an electrically conductive interconnect

Patent metadata

Field	Value
Publication number	US-9437880-B2
Application number	US-201213623455-A
Country	US
Kind code	B2
Filing date	Sep 20, 2012
Priority date	Aug 4, 2006
Publication date	Sep 6, 2016
Grant date	Sep 6, 2016

Abstract

A method of manufacturing a solid oxide fuel cell stack having an electrically conductive interconnect, including the steps of: (a) providing a first fuel cell and a second fuel cell, (b) providing a substrate having an iron-chromium alloy, (c) depositing a layer of metallic cobalt over a portion of substrate surface, (d) subjecting the layer of metallic cobalt to reducing conditions, (e) then exposing the remaining portion of the layer of metallic cobalt to oxidizing conditions for a predetermined time and temperature, such that the surface portion of the layer of metallic cobalt is oxidized to cobalt oxide, thereby forming the electrically conductive interconnect having a layer of metallic cobalt sandwiched between a surface layer of cobalt oxide and the layer of cobalt-iron-chromium alloy, and (f) sandwiching the substrate between the first and second fuel cells.

First claim

What is claimed is:

1. A method of manufacturing a solid oxide fuel cell stack having an electrically conductive interconnect, comprising the steps of:
(a) providing a first fuel cell and a second fuel cell, wherein each of said fuel cells include an electrolyte sandwiched between an anode and a cathode;
(b) providing a substrate comprising an iron-chromium alloy, wherein said substrate includes a first surface and a second surface opposite of said first surface;
(c) depositing a layer of metallic cobalt over at least a portion of at least one of said first and second surfaces;
(d) subjecting said layer of metallic cobalt to reducing conditions for a predetermined time and temperature, such that a portion of said metallic cobalt is diffused into said iron-chromium alloy substrate, thereby forming a layer of cobalt-iron-chromium alloy;
(e) then exposing the remaining portion of said layer of metallic cobalt to oxidizing conditions for a predetermined time and temperature, such that the surface portion of said layer of metallic cobalt is oxidized to cobalt oxide, thereby forming said electrically conductive interconnect comprising said layer of metallic cobalt sandwiched between a surface layer of cobalt oxide and said layer of cobalt-iron-chromium alloy; and
(f) sandwiching said substrate between said first and second fuel cells, wherein said first surface of substrate is in electrical contact said anode of first fuel cell and said second surface of substrate is in electrical contact with said cathode of said second fuel cell.

2. A method according to claim 1 , wherein said reducing conditions comprise heating said layer of metallic cobalt to about 800° C. in a vacuum atmosphere for a time period of about 15 minutes to about 8 hours.

3. A method according to claim 2 , wherein said oxidizing conditions comprise heating the remaining portion of said layer of metallic cobalt in an oxygen-containing atmosphere to a temperature of about 800° C. for a time period of about 15 minutes to about 8 hours.

4. A method according to claim 3 wherein said layer of metallic cobalt has a thickness of about 0.5 micron to about 10 microns.

5. A method according to claim 4 wherein said layer of metallic cobalt has a thickness of about 2.5 microns to about 5 microns.

Assignees

• Mukerjee Subhasish
• Haltiner Jr Karl Jacob
• Meinhardt Kerry D
• Kim Jin Yong
• Mast Eric S
• Sprenkle Vincent L
• Delphi Tech Inc
• Battelle Memorial Institute

Inventors

• Mukerjee Subhasish
• Haltiner Jr Karl Jacob
• Meinhardt Kerry D
• Kim Jin Yong
• Mast Eric S
• Sprenkle Vincent L

Classifications

• H01M8/0228 Primary

  in the form of layered or coated products · CPC title

• H01M8/1246

  the electrolyte consisting of oxides · CPC title

• H01M2300/0071

  Oxides · CPC title

• H01M2008/1293

  Fuel cells with solid oxide electrolytes · CPC title

• H01M8/021

  Alloys based on iron · CPC title