Air electrode material for high temperature electrochemical cells

• US 4,562,124 A
• Filed: 01/22/1985
• Issued: 12/31/1985
• Est. Priority Date: 01/22/1985
• Status: Expired due to Term

• Current Assignee: Siemens Westinghouse Power Corporation
• Original Assignee: Westinghouse Electric Corporation (Paramount Global (f/k/a ViacomCBS Inc.))
• Inventors: Ruka, Roswell J.
• Primary Examiner(s): Skapars, Anthony
• Application Number:
  US06/693,903
• Time in Patent Office: 343 Days
• Field of Search: 429/30, 429/31, 429/32, 429/191, 429/193, 429/101, 429/103, 252/519, 252/521, 252/62.3 R, 204/291, 204/421, 501/152, 420/900, 423/155, 423/596, 423/599
• US Class Current: 429/489
• CPC Class Codes: C04B 35/50 based on rare-earth compounds non-oxide rare earth compounds C04B35/5156
• CPC Class Codes: C25B 11/04 characterised by the material
• CPC Class Codes: G01N 27/4075 Composition or fabrication of the electrodes and coatings thereon, e.g. catalysts
• CPC Class Codes: H01M 4/9016 Oxides, hydroxides or oxygenated metallic salts
• CPC Class Codes: H01M 8/12 operating at high temperature, e.g. with stabilised ZrO2 electrolyte
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

Disclosed is a solid solution with a perovskite-like crystal structure having the general formula

La.sub.1-x-w (M.sub.L).sub.x (Ce).sub.w (M.sub.S1).sub.1-y (M.sub.S2).sub.y

O₃

where M_L is Ca, Sr, Ba, or mixtures thereof, M_S1 is Mn, Cr, or mixtures thereof and M_S2 is Ni, Fe, Co, Ti, Al, In, Sn, Mg, Y, Nb, Ta, or mixtures thereof, w is about 0.05 to about 0.25, x+w is about 0.1 to about 0.7, and y is 0 to about 0.5. In the formula, M_L is preferably Ca, w is preferably 0.1 to 0.2, x+w is preferably 0.4 to 0.7, and y is preferably 0. The solid solution can be used in an electrochemical cell where it more closely matches the thermal expansion characteristics of the support tube and electrolyte of the cell.

Claims

1. A compound comprising a solid solution having the general formula

View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)

2. A compound according to claim 1 wherein M_L is Ca and M_S is selected from the group consisting of 100 mole% Mn, Cr, and mixtures thereof.

3. A compound according to claim 1 wherein w is about 0.1 to about 0.2.

4. A compound according to claim 1 wherein x+w is about 0.4 to about 0.7.

5. A compound according to claim 1 wherein the composition of said solid solution is selected to match the thermal expansion characteristics of a stabilized zirconia electrolyte or electrochemical cell support tube.

6. A compound according to claim 1 having the formula La₀.3 Ca₀.5 to 0.6 Ce₀.2 to 0.1 MnO₃ bonded to a solid solution having the approximate formula (ZrO₂)₀.9 (Y₂ O₃)₀.1.

7. A compound according to claim 1 having the formula La₀.3 Ca₀.5 to 0.6 Ce₀.2 to 0.1 MnO₃ bonded to a solid solution having the approximate formula (ZrO₂)₀.85 (CaO)₀.15.

8. A compound according to claim 1 having the formula La₀.3 Ca₀.5 to 0.6 Ce₀.2 to 0.1 CrO₃ bonded to a solid solution having the approximate formula (ZrO₂)₀.9 (Y₂ O₃)₀.1.

9. A compound according to claim 1 having the formula La₀.3 Ca₀.5 to 0.6 Ce₀.2 to 0.1 CrO₃ bonded to a solid solution having the approximate formula (ZrO₂)₀.85 (CaO)₀.15.

10. A combination support tube and electrode comprising a compound according to claim 1 in the shape of a tube that is porous to gases, where the density of said solid solution does not exceed about 80% of theoretical.

11. In an electrochemical cell, an electrode or electrode current carrier comprising a compound according to claim 1, bonded to an electrolyte, and which may provide mechanical support for other cell members or a components of the cell.

12. An electrode material in a fuel cell, an electrolytic cell, or an oxygen gauge comprising a compound according to claim 1.

13. A compound comprising a solid solution having the general formula