High utilization stack

• US 7,968,245 B2
• Filed: 09/25/2006
• Issued: 06/28/2011
• Est. Priority Date: 09/25/2006
• Status: Active Grant

• Current Assignee: Bloom Energy Corporation
• Original Assignee: Bloom Energy Corporation
• Inventors: Gottmann, Matthias, Armstrong, Tad
• Primary Examiner(s): Gilliam; Barbara L.
• Assistant Examiner(s): Martin; Angela J.
• Application Number:
  US11/526,029
• Publication Number:
  US 20080076006A1
• Time in Patent Office: 1,737 Days
• Field of Search: None
• US Class Current: 429/479
• CPC Class Codes: H01M 2004/8684 Negative electrodes
• CPC Class Codes: H01M 2008/1293 Fuel cells with solid oxide electrolytes
• CPC Class Codes: H01M 4/8642 Gradient in composition
• CPC Class Codes: H01M 4/8647 consisting of more than one material, e.g. consisting of composites
• 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: Y02E 60/50 Fuel cells

Abstract

A solid oxide fuel cell (SOFC) includes a cathode electrode, a solid oxide electrolyte, and an anode electrode. The anode electrode includes a first portion made of a first anode material and a second portion made of a second anode material. The first anode material is a higher performance, lower oxidation resistant material than the second anode material.

Claims

1. A fuel cell system, comprising:

a first fuel cell stack comprising a plurality of fuel cells of a first type;

a second fuel cell stack comprising a plurality of fuel cells of a second type;

wherein;

the fuel cells of the first type and the fuel cells of the second type comprise solid oxide fuel cells;

the second stack is arranged in a cascade configuration with the first fuel cell stack;

the anode electrodes of the fuel cells of the first type comprise a nickel cermet material; and

the anode electrodes of the fuel cells of the second type comprise a titanium containing rutile or pyrochlore material which is a lower performance, higher oxidation resistant material than the nickel cermet material.

2. The system of claim 1, wherein:

the first fuel cell stack comprises a fuel inlet port and a fuel exhaust port; and

the second fuel cell stack comprises a fuel exhaust port and a fuel inlet port which is fluidly connected to the fuel exhaust port of the first stack.

3. The system of claim 2, wherein:

the first stack and the second stack each comprise a fuel inlet riser and a fuel exhaust riser;

the fuel inlet riser of the first stack is connected to the fuel inlet port of the first stack;

the fuel exhaust riser of the first stack is aligned to the fuel inlet riser of the second stack, such that the fuel exhaust port of the first stack and the fuel inlet port of the second stack comprise adjacent contacting portions of the fuel exhaust riser of the first stack and of the fuel inlet riser of the second stack, respectively.

4. The system of claim 1, wherein the anode electrodes of the fuel cells of the first type comprise a nickel-stabilized zirconia material and the anode electrodes of the fuel cells of the second type comprise Nb_0.7Ti_0.3O₂.

5. The system of claim 1, wherein the anode electrodes of the fuel cells of the first type comprise a nickel-stabilized zirconia material and the anode electrodes of the fuel cells of the second type comprise Gd₂Ti_0.6Mo_1.4O₇.

6. A fuel cell system, comprising:

a first fuel cell stack comprising a plurality of fuel cells of a first type;

a second fuel cell stack comprising a plurality of fuel cells of a second type;

wherein;

the fuel cells of the first type and the fuel cells of the second type comprise solid oxide fuel cells;

the second stack is arranged in a cascade configuration with the first fuel cell stack;

the anode electrodes of the fuel cells of the first type comprise a first anode material; and

the anode electrodes of the fuel cells of the second type comprise a second anode material which is a lower performance, higher oxidation resistant material than the first anode material.

7. The system of claim 6, wherein:

the first fuel cell stack comprises a fuel inlet port and a fuel exhaust port; and

the second fuel cell stack comprises a fuel exhaust port and a fuel inlet port which is fluidly connected to the fuel exhaust port of the first stack.

8. The system of claim 7, wherein:

the first stack and the second stack each comprise a fuel inlet riser and a fuel exhaust riser;

the fuel inlet riser of the first stack is connected to the fuel inlet port of the first stack;

the fuel exhaust riser of the first stack is aligned to the fuel inlet riser of the second stack, such that the fuel exhaust port of the first stack and the fuel inlet port of the second stack comprise adjacent contacting portions of the fuel exhaust riser of the first stack and of the fuel inlet riser of the second stack, respectively.

9. The system of claim 6, wherein the anode electrodes of the fuel cells of the first type comprise a nickel cermet material and the anode electrodes of the fuel cells of the second type comprise a titanium containing pyrochlore material.