Claims
- 1. An electrode/electrolyte combination for an oxygen delivery system for delivering oxygen ions through said electrolyte to produce essentially pure O.sub.2 from an O.sub.2 -containing gas mixture, the improvement comprising:
- a thin walled electrolyte having a pair of opposed surfaces
- consisting essentially of ceria, calcia and yttria;
- a three-layer electrode system, consisting essentially of
- a first thin, substantially continuous layer of LSCo adherent to each surface of said electrolyte,
- a second thin, substantially continuous layer of a composite mixture of LSCo and an alloy of Pd and Ag adherent to said first layer, and
- a third thin, substantially continuous layer of silver adherent to said second layer.
- 2. The electrode/electrolyte combination of claim 1, wherein said electrolyte is a ceramic composition having about 99.5-75.0 mol. % of CeO.sub.2, 0.009- 5.0 mol. % Y.sub.2 O.sub.3 and 0.05-20 mol. % CaO.
- 3. The electrode/electrolyte combination of claim 2, wherein said electrolyte is a ceramic composition having about 88 mol. % CeO.sub.2, 2 mol. % Y.sub.2 O.sub.3 and 10 mol. % CaO.
- 4. The electrode/electrolyte combination of claim 1 wherein said electrode layers have a porosity of about 40 to 80%.
- 5. The electrode/electrolyte combination of claim 1 wherein said first electrode layer is about 3 .mu.m to about 12 .mu.m thick; said second electrode layer is about 3 .mu.m to about 12 .mu.m thick and said third electrode layer is about 5 .mu.m to about 100 .mu.m thick.
- 6. The electrode/electrolyte combination of claim 5 wherein said electrode layers have a porosity of about 40 to 80%.
- 7. The electrode/electrolyte combination of claim 1 wherein said second electrode layer is about 25-75 mol. % LSCo and about 75-25 mol. % Ag/Pd alloy.
- 8. The electrode/electrolyte combination of claim 1 wherein said alloy in said second electrode layer is about 60-80 wt % Ag and 40-20 wt % Pd.
RELATED APPLICATIONS
This application is a continuation-in-part of U.S. patent application Ser. No. 432,919 filed on Nov. 6, 1989, now U.S. Pat. No. 5,021,137, which was a continuation-in-part of U.S. patent application Ser. No. 156,549, filed on Feb. 16, 1988, now U.S. Pat. No. 4,879,016, which was a continuation in part of U.S. patent application Ser. No. 889,214, filed Jul. 25, 1986, now U.S. Pat. No. 4,725,346.
US Referenced Citations (12)
Continuation in Parts (3)
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Number |
Date |
Country |
Parent |
432919 |
Nov 1989 |
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Parent |
156549 |
Feb 1988 |
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Parent |
889214 |
Jul 1986 |
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