Preparation of yttria-stabilized zirconia reaction sintered products

1. A method of making a solid electrolyte-YSZ product, the method comprising:

providing separate powders of zirconia, yttria, and a metal oxide and mixing them into a powdered mixture of zirconia, yttria and the metal oxide, wherein yttria-stabilized zirconia is not added to the mixture;

sintering the powdered mixture at about 1500° C. or less, for about 5 hours or less, to form a two-phase composite comprising cubic YSZ and the metal oxide.

2. The method of claim 1 , wherein at least a portion of the metal oxide is reduced to a metal.

3. The method of claim 2 , wherein the metal oxide is reduced to the metal in an atmosphere comprising hydrogen.

4. The method of claim 1 , wherein the metal oxide is nickel oxide.

5. The method of claim 1 , wherein the product is a cermet that is used in an electrode of a solid oxide fuel cell.

6. The method of claim 1 , wherein the powdered mixture comprises about 3-mol % to about 10-mol % yttria.

7. The method of claim 1 , wherein the powdered mixture comprises about 8-mol % yttria.

8. The method of claim 1 , wherein the metal oxide is selected from the group consisting of nickel oxide, iron oxide, cobalt oxide, manganese oxide, copper oxide, and mixtures thereof.

9. A method of making a fuel cell electrode, the method comprising:

forming a green body from separate powders of zirconia, yttria, and a metal oxide that have been mixed together into a powdered mixture comprising zirconia, yttria and the metal oxide, wherein yttria-stabilized zirconia is not added to the green body;

shaping the green body into a form of the electrode;

sintering the green body at about 1500° C. or less to form a two-phased sintered body comprising cubic yttria-stabilized zirconia and the metal oxide; and

reducing the sintered body to form the electrode.

10. The method of claim 9 , wherein the metal oxide is nickel oxide.

11. The method of claim 10 , wherein the reducing of the sintered body reduces at least a portion of the nickel oxide to nickel metal.

12. The method of claim 9 , wherein the green body is sintered for about 5 hours or less.

13. A method of making a ceramic oxide fuel cell, the method comprising:

forming a self-supporting electrode from a YSZ cermet;

forming an electrolyte on the self supporting electrode; and

forming a second electrode on the electrolyte,

wherein the self-supporting electrode is made by:

combining separate powders of zirconia, yttria, and a metal oxide into a powdered mixture of zirconia, yttria and the metal oxide, wherein yttria-stabilized zirconia is not needed; and

sintering the mixture at about 1500° C. or less, for about 5 hours or less, to form a reacted two-phase body comprising cubic yttria-stabilized zirconia and the metal oxide; and

reducing the sintered body to form the self-supporting electrode.

14. The method of claim 13 , wherein the ceramic oxide fuel cell is a solid oxide fuel cell.

15. The method of claim 13 , wherein the ceramic oxide fuel cell is a protonic ceramic fuel cell.

16. The method of claim 13 , wherein the metal oxide comprises nickel oxide.

17. The method of claim 13 , wherein the electrolyte comprises YSZ.

18. A method of making a solid electrolyte-YSZ product, the method comprising:

providing separate powders of zirconia, yttria, and a metal oxide and combing them into a powdered mixture of zirconia, yttria and the metal oxide, wherein yttria-stabilized zirconia is not added to the mixture;

sintering the powdered mixture at about 1500° C. or less, for about 5 hours or less, to form a two-phase composite consisting essentially of YSZ and the metal oxide.