Ceramic interconnect for fuel cell stacks

Patent metadata

Field	Value
Publication number	US-10008727-B2
Application number	US-201314104795-A
Country	US
Kind code	B2
Filing date	Dec 12, 2013
Priority date	Dec 21, 2007
Publication date	Jun 26, 2018
Grant date	Jun 26, 2018

Abstract

A fuel cell comprises a plurality of sub-cells, each sub-cell including a first electrode in fluid communication with a source of oxygen gas, a second electrode in fluid communication with a source of a fuel gas, and a solid electrolyte between the first electrode and the second electrode. The sub-cells are connected with each other with an interconnect. The interconnect includes a first layer in contact with the first electrode of each cell, and a second layer in contact with the second electrode of each cell. The first layer includes a (La,Mn)Sr-titanate based perovskite represented by the empirical formula of La y Sr (1-y) Ti (1-x) Mn x O b . In one embodiment, the second layer includes a (Nb,Y)Sr-titanate perovskite represented by the empirical formula of Sr (1-1.5z-0.5k±δ) Y z Nb k Ti (1-k) O d . In another embodiment, the interconnect has a thickness of between about 10 μm and about 100 μm, and the second layer of the interconnect includes a (La)Sr-titanate based perovskite represented by the empirical formula of Sr (1-z±δ) La z TiO d .

First claim

What is claimed is:

1. A fuel cell, comprising:
a first sub-cell and a second sub cell, each sub-cell including:
a first electrode in fluid communication with a source of oxygen gas,
a second electrode in fluid communication with a source of a fuel gas, and
a solid electrolyte between the first electrode and the second electrode; and

a bi-layer interconnect between the first sub-cell and the second sub cell, wherein:
the interconnect contains no chromium; and
the interconnect includes a first layer including a (La,Mn)Sr-titanate based perovskite represented by an empirical formula of La y Sr (1-y) Ti (1-x) Mn x O b ,
wherein:
x is greater than zero and equal to or less than 0.4;
y is equal to or greater than 0.2 and equal to or less than 0.8; and
b is equal to or greater than 2.5 and equal to or less than 3.5; and

a second layer, wherein the second layer includes a Sr-titanate based perovskite, and Sr, Ti, or both is partially substituted by an element, the second layer being different from the first layer.

2. The fuel cell of claim 1 , wherein the interconnect is planar.

3. The fuel cell of claim 1 , wherein the second layer includes a (Nb,Y)Sr-titanate based perovskite.

4. The fuel cell of claim 1 , wherein the second layer includes a (La)Sr-titanate based perovskite.

5. The fuel cell of claim 1 , wherein a thickness of the interconnect is in a range of between about 0.005 mm and about 2.0 mm.

6. The fuel cell of claim 1 , wherein a thickness of the interconnect is in a range of between about 10 μm and about 100 μm.

7. The fuel cell of claim 1 , wherein the interconnect has a density of greater than about 90% of a theoretical density.

8. The fuel cell of claim 1 , wherein the interconnect has a density of greater than about 94% of a theoretical density.

9. The fuel cell of claim 4 , wherein the (La)Sr-titanate based perovskite is represented by an empirical formula of Sr (1-z±δ) La z TiO d , wherein:
z is greater than zero and equal to or less than 0.4;
d is equal to or greater than 2.5 and equal to or less than 3.5; and
δ is equal to or greater than zero and equal to or less than 0.05.

10. The fuel cell of claim 1 , wherein the interconnect has a thickness of between 10 microns and 100 microns.

11. The fuel cell of claim 1 , wherein the (La,Mn)Sr-titanate based perovskite is represented by the empirical formula of La 0.4 Sr 0.6 Ti (1-x) Mn x O b .

12. The fuel cell of claim 3 , wherein the (Nb,Y)Sr-titanate based perovskite is represented by an empirical formula of Sr (1-1.5z-0.5k±δ) Y z Nb k Ti (1-k) O d , wherein
each of k and z independently is equal to or greater than zero and equal to or less than 0.2;
k+z>0;
d is equal to or greater than 2.5 and equal to or less than 3.5; and
δ is equal to or greater than zero and equal to or less than 0.05.

13. A fuel cell, comprising:
a first sub-cell and a second sub cell, each sub-cell including:
a first electrode in fluid communication with a source of oxygen gas,
a second electrode in fluid communication with a source of a fuel gas, and
a solid electrolyte between the first electrode and the second electrode; and

a bi-layer interconnect between the first sub-cell and the second sub cell, wherein:
the interconnect contains no chromium; and
the interconnect includes a first layer closer to the first electrode than the second electrode, the first layer including a (La,Mn)Sr-titanate based perovskite represented by an empirical formula of La y Sr (1-y) Ti (1-x) Mn x O b , wherein:
x is greater than zero and less than 0.4;
y is equal to or greater than 0.2 and equal to or less than 0.8; and
b is equal to or greater than 2.5 and equal to or less than 3.5; and

a second layer closer to the second electrode than the first electrode, the second layer including:
a (Nb,Y)Sr-titanate based perovskite represented by represented by an empirical formula of Sr (1-1.5z-0.5k±δ )Y z Nb k Ti (1-k) O d , wherein
each of k and z independently is equal to or greater than zero and equal to or less than 0.2;
k+z>0;
d is equal to or greater than 2.5 and equal to or less than 3.5; and
δ is equal to or greater than zero and equal to or less than 0.05; or

a (La)Sr-titanate based perovskite represented by an empirical formula of Sr (1-z±δ )La z TiO d , wherein:
z is greater than zero and equal to or less than 0.4;
d is equal to or greater than 2.5 and equal to or less than 3.5; and
δ is equal to or greater than zero and equal to or less than 0.05.

14. The fuel cell of claim 13 , wherein the (La,Mn)Sr-titanate based perovskite is represented by the empirical formula of La 0.4 Sr 0.6 Ti (1-x) Mn x O b .

Assignees

• Saint Gobain Ceramics

Inventors

• Lin Guangyong

Classifications

• H01M8/0228

  in the form of layered or coated products · CPC title

• C04B35/47

  based on strontium titanates · CPC title

• H01M8/0217 Primary

  Complex oxides, optionally doped, of the type AMO3, A being an alkaline earth metal or rare earth metal and M being a metal, e.g. perovskites · CPC title

• C04B2235/3227

  Lanthanum oxide or oxide-forming salts thereof · CPC title

• H01M8/1226

  characterised by the supporting layer · CPC title