초록

A ceramic electrolyte for a solid oxide fuel cell includes at least one non-uniform surface portion. Preferably, the electrolyte surface is textured.

대표청구항 ▼

What is claimed is: 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

What is claimed is: 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.