Textured electrolyte for a solid oxide fuel cell
View Patent ↗A ceramic electrolyte for a solid oxide fuel cell includes at least one non-uniform surface portion. Preferably, the electrolyte surface is textured.
1. A ceramic electrolyte for a solid oxide fuel cell, comprising at least one non-uniform surface portion, wherein:
the electrolyte is substantially flat; and
the at least one non-uniform surface portion of the electrolyte comprises a textured surface which is located only in an active portion of the electrolyte, while a peripheral portion of the electrolyte does not contain the textured surface.
2. The electrolyte of claim 1 , wherein the peripheral portion of the electrolyte contains at least one of oxygen or fuel passages.
3. The electrolyte of claim 2 , wherein the electrolyte comprises two opposing non-uniform textured surface portions.
4. The electrolyte of claim 1 , wherein an imaginary center line running along a length of the electrolyte does not significantly deviate from an imaginary straight line.
5. The electrolyte of claim 1 , wherein the at least one non-uniform surface portion of the electrolyte comprises two opposing major textured surfaces which are located only in the active portion of the electrolyte, while a peripheral portion of the electrolyte does not contain the textured surfaces.
6. The electrolyte of claim 1 , wherein the textured surface comprises protrusions having a height that is 5% or less of an average electrolyte thickness.
7. The electrolyte of claim 1 , wherein the textured surface has a roughness of 0.5 to 2.5 microns.
8. The electrolyte of claim 1 , wherein:
the electrolyte comprises a composite electrolyte having a first layer and a second layer; and
the textured surface comprises an interface surface between the first and the second layers.
9. The electrolyte of claim 8 , further comprising an outer textured surface of the composite electrolyte, wherein the composite electrolyte comprises at least three layers and at least two textured interfaces.
10. The electrolyte of claim 8 , wherein the first layer comprises a doped ceria and the second layer comprises YSZ.
11. The electrolyte of claim 1 , wherein the electrolyte comprises YSZ.
12. A solid oxide fuel cell, comprising:
the electrolyte of claim 3 ;
an anode contacting a first non-uniform surface of the electrolyte; and
a cathode contacting a second non-uniform surface of the electrolyte.
13. The fuel cell of claim 12 , wherein:
the anode comprises a nickel-YSZ cermet; and
the cathode comprises LSM.
14. A solid oxide fuel cell stack, comprising a plurality of solid oxide fuel cells of claim 12 .
15. A method of making a ceramic electrolyte for a solid oxide fuel cell, comprising:
providing a substantially flat ceramic electrolyte; and
texturing at least a portion of one surface of the ceramic electrolyte by lapping, grinding or polishing at least one surface of the electrolyte.
16. The method of claim 15 , wherein the step of texturing comprises texturing both opposing surfaces of the ceramic electrolyte after sintering the electrolyte.
17. The method of claim 15 , wherein:
the textured surface portion is located only in an active portion of the electrolyte, while a peripheral portion of the electrolyte does not contain the textured surface; and
an imaginary center line running along a length of the electrolyte does not significantly deviate from an imaginary straight line.
18. The method of claim 15 , wherein the step of texturing comprises lapping, grinding or polishing both opposing surfaces of the ceramic electrolyte.
19. The method of claim 18 , wherein the textured surface has a roughness of 0.5 to 2.5 microns.
20. A method of making a solid oxide fuel cell, comprising:
providing the electrolyte made by the method of claim 15 ;
forming an anode on a first non-uniform surface of the electrolyte; and
forming a cathode on a second non-uniform surface of the electrolyte.
21. A method of making a ceramic electrolyte for a solid oxide fuel cell by tape casting, comprising:
providing a slurry containing a ceramic powder onto a textured material;
spreading the slurry using a blade to form a green tape; and
sintering the green tape to form a substantially flat ceramic electrolyte containing at least a textured surface portion.
22. The method of claim 21 , wherein the step of providing a slurry comprises providing the slurry onto a moving carrier tape.
23. The method of claim 21 , wherein the textured surface portion is located only in an active portion of the electrolyte, while a peripheral portion of the electrolyte does not contain the textured surface.
24. The method of claim 23 , wherein:
the peripheral portion of the electrolyte contains at least one of oxygen or fuel passages; and
an imaginary center line running along a length of the electrolyte does not significantly deviate from an imaginary straight line.
25. The method of claim 21 , wherein the textured surface portion comprises an entire major surface of the electrolyte.
26. The method of claim 21 , further comprising placing the electrolyte which comprises YSZ into a solid oxide fuel cell.
27. A method of making a ceramic electrolyte for a solid oxide fuel cell, comprising:
providing an electrolyte precursor material;
texturing at least a portion of one surface of the electrolyte precursor material by embossing at least a portion of one surface of the electrolyte precursor material, wherein the step of embossing comprises rolling a body having a textured surface against the electrolyte precursor material; and
sintering the electrolyte precursor material to form a substantially flat ceramic electrolyte containing at least a textured surface portion.
28. The method of claim 27 , wherein the electrolyte precursor material comprises a green sheet.
29. The method of claim 27 , wherein the textured surface portion comprises an entire major surface of the electrolyte.
30. The method of claim 27 , wherein the textured surface portion is located only in an active portion of the electrolyte, while a peripheral portion of the electrolyte does not contain the textured surface.
31. The method of claim 30 , wherein:
the peripheral portion of the electrolyte contains at least one of oxygen or fuel passages; and
an imaginary center line running along a length of the electrolyte does not significantly deviate from an imaginary straight line.
32. The method of claim 27 , further comprising placing the electrolyte which comprises YSZ into a solid oxide fuel cell.
33. The method of claim 27 , wherein the step of embossing comprises rolling a first body having a textured surface against a first surface of the electrolyte precursor material and rolling a second body having a textured surface against a second surface of the electrolyte precursor material to form an electrolyte comprising two opposing textured surface portions.