Metastable ceramic fuel cell and method of making the same

• US 8,334,079 B2
• Filed: 04/30/2004
• Issued: 12/18/2012
• Est. Priority Date: 04/30/2004
• Status: Active Grant

• Current Assignee: Nano Cell Systems Inc.
• Original Assignee: Nano Cell Systems Inc.
• Inventors: Strutt, Peter R., Kear, Bernard H.
• Primary Examiner(s): Hodge, Robert
• Application Number:
  US10/837,517
• Publication Number:
  US 20050244693A1
• Time in Patent Office: 3,154 Days
• Field of Search: None
• US Class Current: 429/489
• CPC Class Codes: H01M 2004/8684 Negative electrodes
• CPC Class Codes: H01M 2004/8689 Positive electrodes
• CPC Class Codes: H01M 4/8621 containing only metallic or ceramic material, e.g. made by sintering or sputtering
• CPC Class Codes: H01M 4/8652 as mixture
• CPC Class Codes: H01M 4/886 Powder spraying, e.g. wet or dry powder spraying, plasma spraying
• CPC Class Codes: H01M 4/8878 Treatment steps after deposition of the catalytic active composition or after shaping of the electrode being free-standing body
• CPC Class Codes: H01M 4/9025 Oxides specially used in fuel cell operating at high temperature, e.g. SOFC
• 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 8/1016 characterised by the electrolyte material H01M8/12 takes precedence
• CPC Class Codes: H01M 8/1253 the electrolyte containing zirconium oxide
• CPC Class Codes: H01M 8/1286 Fuel cells applied on a support, e.g. miniature fuel cells deposited on silica supports
• 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 fuel cell has anode, cathode and electrolyte layers each formed essentially of a multi-oxide ceramic material and having a far-from-equilibrium, metastable structure selected from the group consisting of nanocrystalline, nanocomposite and amorphous. The electrolyte layer has a matrix of the ceramic material, and is impervious and serves as a fast oxygen ion conductor. The electrolyte layer has a matrix of the ceramic material and a dopant dispersed therein in an amount substantially greater than its equilibrium solubility in the ceramic matrix. The anode layer includes a continuous surface area metallic phase in which electron conduction is provided by the metallic phase and the multi-oxide ceramic matrix provides ionic conduction.

Claims

1. A solid oxide fuel cell having anode, cathode and electrolyte layers each formed essentially of a multi-oxide ceramic material, said electrolyte layer being a uniform deposit formed by thermal quenching at a rate of about 10⁶ degrees Kelvin per second to about 10⁸ degrees Kelvin per second and having a structure selected from the group consisting of nanocrystalline, nanocomposite and amorphous, each of said structures being a far-from-equilibrium metastable structure, said electrolyte layer having a matrix of multi-oxide ceramic material comprising an 8-12 mole % yttria-stabilized zirconia, said electrolyte layer serving as a fast oxygen ion conductor.

2. A solid oxide fuel cell in accordance with claim 1 wherein the matrix has dispersed therein at least one dopant.

3. A solid oxide fuel cell in accordance with claim 1 wherein said electrolyte layer has a matrix of said ceramic material and a dopant dispersed therein to form the metastable structure.

4. A solid oxide fuel cell in accordance with claim 3 wherein said structure of such electrolyte layer minimizes (i) vacancy-vacancy, (ii) vacancy dopant, and (iii) dopant-dopant ordering to minimize restriction of oxygen ion mobility.

5. A solid oxide fuel cell in accordance with claim 4 wherein said dopant introduces elastic strain to counteract electrostatically-induced ordering.

6. A solid oxide fuel cell in accordance with claim 1 wherein said anode layer is porous.

7. A solid oxide fuel cell in accordance with claim 1 wherein said anode layer includes a continuous surface area metallic phase in which electron conduction is provided by said metallic phase and said multi-oxide ceramic matrix provides ionic conduction.

8. A solid oxide fuel cell in accordance with claim 6 wherein said cathode layer is porous and comprises a multi-oxide ceramic material which provides mixed ionic and electron conduction.

9. A solid oxide fuel cell in accordance with claim 8 wherein said porous cathode layer is a composite structure in which one multi-oxide continuous ceramic phase provides electron conduction and another multi-oxide continuous ceramic phase provides ionic conduction.

10. A solid oxide fuel cell in accordance with claim 1 wherein said electrolyte layer defines a contiguous YSZ phase and has a graded interface with said anode and cathode layers, said graded interface comprising a nanoscale blending and penetration of said contiguous YSZ phase into said anode and cathode layers.

11. A solid oxide fuel cell in accordance with claim 1 wherein both of said anode and cathode layers are porous to permit diffusion.

12. A solid oxide fuel cell in accordance with claim 11 wherein the porosity is nano-porosity.