Preparation of a solid oxide fuel cell having thin electrolyte and interconnect layers

• US 5,788,788 A
• Filed: 06/10/1996
• Issued: 08/04/1998
• Est. Priority Date: 01/29/1993
• Status: Expired due to Term

• Current Assignee: Hybrid Power Generation Systems, LLC
• Original Assignee: Alliedsignal Inc. (Honeywell International Inc.)
• Inventors: Minh, Nguyen Q.
• Primary Examiner(s): Fiorilla, Christopher A.
• Application Number:
  US08/662,724
• Time in Patent Office: 785 Days
• Field of Search: 156/89, 156/62.2, 156/87, 264/614
• US Class Current: 156/62.2
• CPC Class Codes: B28B 1/002 assembled from preformed elements
• CPC Class Codes: B32B 2457/16 Capacitors
• CPC Class Codes: B32B 2457/18 Fuel cells
• CPC Class Codes: B32B 5/16 characterised by features of a layer formed of particles, e.g. chips, powder or granules layer formed of natural mineral particles B32B19/00; layer being formed of wood fibres, chips or particles B32B21/02
• CPC Class Codes: B32B 9/00 Layered products comprising a layer of a particular substance not covered by groups B32B11/00 - B32B29/00
• CPC Class Codes: B32B 9/005 comprising one layer of ceramic material, e.g. porcelain, ceramic tile layered products with at least two ceramic layers composed mainly of ceramic B32B18/00
• CPC Class Codes: B32B 9/048 made of particles
• CPC Class Codes: H01G 4/30 Stacked capacitors H01G4/33 takes precedence
• CPC Class Codes: H01M 2008/1293 Fuel cells with solid oxide electrolytes
• CPC Class Codes: H01M 2300/0074 Ion conductive at high temperature
• 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 8/1213 characterised by the electrode/electrolyte combination or the supporting material
• CPC Class Codes: H01M 8/1231 with both reactants being gaseous or vaporised
• 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 method of preparing a fuel cell element includes the steps of: laminating ceramic tapes to form an unfired anode/electrolyte laminate; reducing the thickness of the anode/electrolyte laminate; sintering the anode/electrolyte laminate; laminating ceramic tapes to form an unfired cathode/interconnect laminate; reducing the thickness of the cathode/interconnect laminate; embossing a gas flow path pattern into the cathode layer of the cathode/interconnect laminate; sintering the cathode/interconnect laminate; and bonding the sintered anode/electrolyte laminate to the sintered cathode/interconnect laminate such that the electrolyte layer contacts the cathode layer. The fuel cell produced by this method has thin electrolyte and interconnect layers which result in high fuel cell outlet power.

Claims

1. A method of preparing a fuel cell element comprising the steps of;

preparing a first unfired ceramic tape comprising an anode material;

preparing a second unfired ceramic tape comprising an electrolyte material, the second ceramic tape being less than about 1/5 the thickness of the first ceramic tape;

laminating the first ceramic tape and the second ceramic tape to form an unfired anode/electrolyte laminate, said electrolyte material forming an electrolyte layer of said unfired anode/electrolyte laminate, and said anode material forming an anode layer of said unfired anode/electrolyte laminate;

rolling the unfired anode/electrolyte laminate to reduce its thickness;

embossing a gas flow path pattern into the anode layer of the unfired anode/electrolyte laminate;

sintering the unfired anode/electrolyte laminate to form a sintered anode/electrolyte laminate;

preparing a third unfired ceramic tape comprising a cathode material;

preparing a fourth unfired ceramic tape comprising an interconnect material, the fourth ceramic tape being less than about 1/5 the thickness of the third ceramic tape;

laminating the fourth ceramic tape and the third ceramic tape to form an unfired cathode/interconnect laminate, said cathode material forming a cathode layer of said unfired cathode/interconnect laminate, and said interconnect material forming an interconnect layer of said cathode/interconnect laminate;

rolling the unfired cathode/interconnect laminate to reduce its thickness;

embossing a gas flow path pattern into the cathode layer of the unfired cathode/interconnect laminate;

sintering the unfired cathode/interconnect laminate to form a sintered cathode/interconnect laminate; and

bonding the sintered anode/electrolyte laminate to the sintered cathode/interconnect laminate, such that the electrolyte layer contacts the cathode layer, to form a fuel cell element.

2. The method of claim 1, wherein the step of rolling the unfired anode/electrolyte laminate includes the step of

reducing the thickness of the anode/electrolyte laminate so that the thickness of the anode layer is from about 0.25 millimeter to about 1 millimeter and the thickness of the electrolyte layer is from about 1 to about 10 micrometers.

3. The method of claim 1, wherein the step of rolling the unfired anode/electrolyte laminate includes the step of

reducing the thickness of the cathode/interconnect laminate so that the thickness of the cathode layer is from about 0.25 millimeter to about 1 millimeter and the thickness of the interconnect layer is from about 1 to about 10 micrometers.

4. The method of claim 1, including the additional step, after the step of bonding

stacking and bonding a plurality of the fuel cell elements together.

5. The method of claim 1, including the additional steps, after the step of rolling the unfired anode/electrolyte laminate and before the step of embossing a gas flow path pattern into the anode layer, of laminating at least one additional first unfired ceramic tape to the anode layer of the unfired anode/electrolyte laminate, and rolling the resulting laminate to reduce its thickness.

6. The method of claim 1, including the additional steps, after the step of rolling the unfired cathode/interconnect laminate and before the step of embossing a gas flow pattern into the cathode layer, of laminating at least one additional third unfired ceramic tape to the cathode layer of the unfired cathode/interconnect laminate, and rolling the resulting laminate to reduce its thickness.