SORFC system with non-noble metal electrode compositions

• US 7,887,971 B2
• Filed: 11/09/2006
• Issued: 02/15/2011
• Est. Priority Date: 09/10/2003
• Status: Active Grant

• Current Assignee: Bloom Energy Corporation
• Original Assignee: Bloom Energy Corporation
• Inventors: Russell, Ian, Hickey, Darren
• Primary Examiner(s): Ryan; Patrick
• Assistant Examiner(s): APICELLA, KARIE O
• Application Number:
  US11/594,797
• Publication Number:
  US 20070054176A1
• Time in Patent Office: 1,559 Days
• Field of Search: 429/413, 429/479, 429/487, 429/527
• US Class Current: 429/487
• CPC Class Codes: H01M 4/8621 containing only metallic or ceramic material, e.g. made by sintering or sputtering
• CPC Class Codes: H01M 4/8885 Sintering or firing
• CPC Class Codes: H01M 4/9016 Oxides, hydroxides or oxygenated metallic salts
• CPC Class Codes: H01M 4/9033 Complex oxides, optionally doped, of the type M1MeO3, M1 being an alkaline earth metal or a rare earth, Me being a metal, e.g. perovskites
• CPC Class Codes: H01M 4/9066 of metal-ceramic composites or mixtures, e.g. cermets
• CPC Class Codes: H01M 8/04097 with recycling of the reactants H01M8/04119, H01M8/04104 take precedence
• CPC Class Codes: H01M 8/04164 by condensers, gas-liquid separators or filters
• CPC Class Codes: H01M 8/1253 the electrolyte containing zirconium oxide
• CPC Class Codes: H01M 8/126 the electrolyte containing cerium oxide
• CPC Class Codes: H01M 8/186 by electrolytic decomposition of the electrolytic solution or the formed water product
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

A solid oxide regenerative fuel cell includes a ceramic electrolyte, a first electrode which is adapted to be positively biased when the fuel cell operates in a fuel cell mode and in an electrolysis mode, and a second electrode which is adapted to be negatively biased when the fuel cell operates in the fuel cell mode and in the electrolysis mode. The second electrode comprises less than 1 mg/cm² of noble metal.

Claims

1. A solid oxide regenerative fuel cell, comprising:

a ceramic electrolyte;

a first electrode which is adapted to be positively biased when the fuel cell operates in a fuel cell mode and in an electrolysis mode;

a second electrode which is adapted to be negatively biased when the fuel cell operates in the fuel cell mode and in the electrolysis mode; and

a first device which is adapted to provide a reducing atmosphere to the second electrode when the fuel cell operates in the electrolysis mode to prevent the second electrode from oxidizing;

wherein;

the second electrode comprises less than 0.1 mg/cm² of noble metal and less than 1 weight percent of noble metal; and

the second electrode comprises at least one of Ni, Cu, Fe or a combination thereof with an ionic conducting phase.

2. The fuel cell of claim 1, wherein the second electrode consists essentially of a Ni-YSZ cermet.

3. The fuel cell of claim 1, wherein:

the second electrode consists essentially of a Ni-doped ceria cermet; and

the electrolyte comprises a doped ceria portion in contact with the second electrode and a YSZ portion in contact with the first electrode.

4. The fuel cell of claim 1, wherein:

the electrolyte comprises YSZ, doped ceria or a combination thereof; and

the first electrode comprises at least one of LSM, LSCo, LCo, LSF, LSCoF, PSM or a combination thereof with an ionic conducting phase.

5. The fuel cell of claim 1, wherein the first device comprises a hydrogen conduit operatively connected to at least one of a hydrogen compressor and a hydrogen fuel storage vessel.

6. The fuel cell of claim 5, wherein the hydrogen conduit is operatively connected to a fuel inlet of a fuel cell stack and a fuel outlet of the fuel cell stack is operatively connected to a water-hydrogen separator.

7. The fuel cell of claim 6, wherein the water-hydrogen separator is operatively connected to the fuel inlet of the fuel cell stack and is adapted to provide water to the second electrode when the fuel cell operates in the electrolysis mode.

8. The fuel cell of claim 5, further comprising a valve which is adapted to bleed a first sufficient amount of hydrogen from at least one of the hydrogen compressor and the hydrogen fuel storage vessel through the hydrogen conduit to the second electrode to prevent the second electrode from oxidizing when the fuel cell operates in the electrolysis mode and which is adapted to provide hydrogen fuel from the hydrogen storage vessel through the hydrogen conduit to the second electrode in a second amount greater than the first amount when the fuel cell operates in the fuel cell mode.

9. The fuel cell of claim 5, wherein the first device comprises a forming gas conduit operatively connected to a forming gas storage vessel.

10. The fuel cell of claim 5, wherein the first device comprises a carbon monoxide conduit operatively connected to a carbon monoxide storage vessel.