Electrolyte forming process for a metal-supported solid-oxide fuel cell

Patent metadata

Field	Value
Publication number	US-10978727-B2
Application number	US-201514672285-A
Country	US
Kind code	B2
Filing date	Mar 30, 2015
Priority date	Feb 6, 2015
Publication date	Apr 13, 2021
Grant date	Apr 13, 2021

Abstract

A process for forming an electrolyte for a metal-supported solid-oxide fuel cell, the process comprising:
a. applying a doped-ceria green electrolyte to an anode layer; b. removing any solvents and organic matter from the green electrolyte; c. pressing the green electrolyte to increase green electrolyte density; and d. heating the green electrolyte at a rate of temperature increase whilst in the temperature range 800° C.-1000° C. of in the range 5-20° C./minute to form the electrolyte,

together with an electrolyte obtained by the process, a fuel cell and fuel cell stack, comprising the electrolyte, and the use of the fuel in the generation of electrical energy.

First claim

The invention claimed is:

1. A process for forming a metal-supported solid-oxide fuel cell comprising:
providing a metal-supported anode layer comprising an anode layer that has been applied to a flat metal substrate;
forming an electrolyte on the metal-supported anode layer using a process comprising:
a. applying a doped-ceria green electrolyte to the metal-supported anode layer;
b. removing any solvents and organic matter from the green electrolyte;
c. pressing the green electrolyte to increase green electrolyte density;
d. applying a pinning mass to at least part of the part of the metal substrate onto which neither an anode nor an electrode material has been applied to hold the metal substrate flat during sintering; and
e. heating the green electrolyte at a rate of temperature increase whilst in the temperature range 800° C. to 1000° C. of in the range 5° C./minute to 20° C./minute to sinter the green electrolyte to form the electrolyte and thereafter removing the pinning mass; and

applying a cathode material to the electrolyte.

2. The process according to claim 1 , further comprising: forming the doped-ceria green electrolyte from a screen-printable ink.

3. The process according to claim 1 , wherein the flat metal substrate comprises a perforated region surrounded by a non-perforated region.

4. The process according to claim 1 , wherein removing any solvents and organic matter from the green electrolyte comprises evaporating the solvents.

5. The process according to claim 1 , wherein removing any solvents and organic matter comprises heating the green electrolyte to a temperature in the range of 250° C. to 500° C. until the organic matter has decomposed.

6. The process according to claim 1 , wherein the anode layer is a sintered anode layer.

7. The process according to claim 1 , wherein the anode layer is a green anode layer and the green anode layer and green electrolyte are sintered in a single firing step.

8. The process according to claim 1 , wherein the green electrolyte comprises multiple layers of electrolyte formed by applying the green electrolyte in layers over the anode layer, with drying between the application of each layer of the green electrolyte.

9. The process according to claim 1 , wherein pressing of the green electrolyte comprises application of a pressure in the range of 50 MPa to 500 MPa.

10. The process according to claim 1 , wherein the electrolyte covers the anode layer and the flat metal substrate.

11. The process according to claim 1 , wherein electrolyte layer covers the anode layer and another portion of the flat metal substrate that is not covered by the anode layer.

12. The process according to claim 1 , wherein the heating the green electrolyte is performed in air.

13. The process according to claim 1 , wherein pressing is achieved using cold isostatic pressing or uniaxial bladder pressing.

14. The process according to claim 1 , wherein the metal substrate is a stainless steel substrate.

15. The process according to claim 1 , wherein the temperature of step e. is less than 1100° C.

16. The process according to claim 1 , wherein step e. is performed in air.

17. The process according to claim 4 , wherein the step of evaporating the solvents comprises evaporation at a temperature in the range 100° C. to 250° C.

18. A process for forming a metal-supported solid-oxide fuel cell comprising:
providing a metal-supported anode layer comprising an anode layer that has been applied to a flat metal substrate;
wherein the flat metal substrate comprises a ferritic stainless steel foil substrate made partially porous in its central region, such that the flat metal substrate comprises a perforated region surrounded by a non-perforated region;
wherein the anode layer has been deposited as a film on the foil substrate;

forming an electrolyte on the metal-supported anode layer using a process comprising:
a. applying a doped-ceria green electrolyte to the metal-supported anode layer;
b. removing any solvents and organic matter from the green electrolyte;
c. pressing the green electrolyte to increase green electrolyte density;
d. applying a pinning mass to at least part of the non-perforated region of the metal substrate onto which neither an anode nor an electrode material has been applied to hold the metal substrate flat during sintering; and
e. heating the green electrolyte at a rate of temperature increase whilst in the temperature range 800° C. to 1000° C. of in the range 5° C./minute to 20° C./minute to sinter the green electrolyte to form the electrolyte, and thereafter removing the pinning mass;
wherein the heating the green electrolyte is performed in air; and

applying a cathode material to the electrolyte.

Assignees

• Ceres Ip Co Ltd

Inventors

• Leah Robert
• Bone Adam
• Matthews Carl
• Lankin Mike
• Rahman Mahfujur
• Selcuk Ahmet

Classifications

• H01M8/124

  characterised by the process of manufacturing or by the material of the electrolyte · CPC title

• H01M8/1213 Primary

  characterised by the electrode/electrolyte combination or the supporting material · CPC title

• Y02E60/50

  Fuel cells · CPC title

• H01M2300/0094

  in the form of layered products, e.g. coatings · CPC title

• H01M8/126 Primary

  the electrolyte containing cerium oxide · CPC title