ELECTRODE-SUPPORTED TUBULAR SOLID-OXIDE ELECTROCHEMICAL CELL

• US 20170101719A1
• Filed: 10/08/2015
• Published: 04/13/2017
• Est. Priority Date: 10/08/2015
• Status: Active Grant

• Current Assignee: Transformational Energy Limited
• Original Assignee: Low Emissions Resources Corporation
• Inventors: Alvarez, Fernando, Sammes, Nigel Mark
• Granted Patent: US 10,458,027 B2
• Time in Patent Office: Days
• CPC Class Codes: C25B 11/02 characterised by shape or form
• CPC Class Codes: C25B 11/031 Porous electrodes
• CPC Class Codes: C25B 13/02 characterised by shape or form
• CPC Class Codes: C25B 13/04 characterised by the material
• CPC Class Codes: C25B 9/19 with diaphragms
• CPC Class Codes: H01M 2300/0074 Ion conductive at high temperature
• CPC Class Codes: H01M 4/8864 Extrusion
• CPC Class Codes: H01M 4/8885 Sintering or firing
• CPC Class Codes: H01M 4/9025 Oxides specially used in fuel cell operating at high temperature, e.g. SOFC
• CPC Class Codes: H01M 8/1213 characterised by the electrode/electrolyte combination or the supporting material
• CPC Class Codes: H01M 8/124 characterised by the process of manufacturing or by the material of the electrolyte
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

Electrode-supported tubular solid-oxide electrochemical cells suitable for use in electrochemical chemical synthesis and processes for manufacturing such are provided.

Claims

1. A tubular solid-oxide electrochemical cell comprising:

a first porous electrode configured in a tubular shape, the first porous electrode comprising a first mixed ionically/electronically conductive composite material of a solid-oxide electrolyte substance and a first electrochemically active substance;

an electrolyte disposed as a thin-layer on at least part of a surface of the first porous electrode, the electrolyte comprising the solid-oxide electrolyte substance; and

a second porous electrode disposed on at least part of a surface of the electrolyte, the second porous electrode comprising a second mixed ionically/electronically conductive composite material of the solid-oxide electrolyte substance and a second electrochemically active substance.

2. The tubular solid-oxide electrochemical cell of claim 1, wherein the solid-oxide electrolyte substance comprises a proton conducting material.

3. The tubular solid-oxide electrochemical cell of claim 1, wherein the solid-oxide electrolyte substance comprises an oxygen ion conducting material.

4. The tubular solid-oxide electrochemical cell of claim 1, wherein the solid-oxide electrolyte substance comprises a material selected from the group consisting of:

a perovskite, a fluorite, a pyrochlore and a brownmillerite.

5. The tubular solid-oxide electrochemical cell of claim 1, wherein the solid-oxide electrolyte substance comprises a perovskite material having a general formula ABO₃, wherein A is selected from the group consisting of:

monovalent, divalent and trivalent metal cations and combinations thereof; and

B is selected from the group consisting of;

pentavalent, tetravalent and trivalent metal cations and combinations thereof.

6. The tubular solid-oxide electrochemical cell of claim 1, wherein the solid-oxide electrolyte substance comprises a fluorite material having a general formula MO₂, wherein M is selected from the group consisting of divalent and trivalent metal cations and combinations thereof.

7. The tubular solid-oxide electrochemical cell of claim 1, wherein the first porous electrode comprises at least about 70% by weight of the solid-oxide electrolyte substance.

8. The tubular solid-oxide electrochemical cell of claim 1, wherein the first electrochemically active substance is selected from the group consisting of:

Sc, Ti, Zn, Sr, Y, Zr, Au, Bi, Pb, Co, Pt, Ru, Pd, Ni, Cu, Ag, W, Os, Rh, Ir, Cr, Fe, Mo, V, Re, Mn, Nb, Ta, and oxides, alloys and mixtures thereof.

9. The tubular solid-oxide electrochemical cell of claim 1, wherein the second porous electrode comprises at least about 70% by weight of the solid-oxide electrolyte substance.

10. The tubular solid-oxide electrochemical cell of claim 1, wherein the second electrochemically active substance is selected from the group consisting of:

Sc, Ti, Zn, Sr, Y, Zr, Au, Bi, Pb, Co, Pt, Ru, Pd, Ni, Cu, Ag, W, Os, Rh, Ir, Cr, Fe, Mo, V, Re, Mn, Nb, Ta, and oxides, alloys and mixtures thereof.

11. The tubular solid-oxide electrochemical cell of claim 1, wherein the first mixed ionically/electronically conductive composite material and the second mixed ionically/electronically conductive composite material are the same.

12. The tubular solid-oxide electrochemical cell of claim 1, wherein the first porous electrode has an average thickness in a range of about 5 mm to about 50 mm.

13. The tubular solid-oxide electrochemical cell of claim 1, wherein the thin-layer of the electrolyte has an average thickness in a range of about 5 microns to about 100 microns.

14. The tubular solid-oxide electrochemical cell of claim 1, wherein the second porous electrode has an average thickness in a range of about 5 microns to about 100 microns.

15. The tubular solid-oxide electrochemical cell of claim 1, wherein the tubular shape has a cross-sectional shape selected from the group consisting of:

circular, semicircular, oval, square, rectangular, trapezoidal, triangular and star.

16. The tubular solid-oxide electrochemical cell of claim 1, wherein the first mixed ionically/electronically conductive composite material and the second mixed ionically/electronically conductive composite material each has a coefficient of thermal expansion within about 10% of that of the solid-oxide electrolyte substance.

17. A tubular solid-oxide electrochemical cell made by a process comprising the steps of:

extruding an electrode dough in a tubular shape to form a first electrode, the electrode dough comprising a solid-oxide electrolyte substance, a first electrochemically active substance, a carbon-based pore forming substance, a binder and a solvent;

sintering the extruded first electrode to cause the carbon-based pore forming substance to burn off and for pores in the first electrode;

forming an electrolyte onto at least part of a surface of the sintered first electrode, the electrolyte comprising a thin-layer of the solid-oxide electrolyte substance; and

forming a second electrode onto at least part of a surface of the electrolyte, the second electrode comprising the solid-oxide electrolyte substance and a second electrochemically active substance.

18. The tubular solid-oxide electrochemical cell of claim 17, wherein the first electrochemically active substance and the second electrochemically active substance are the same.

19. The tubular solid-oxide electrochemical cell of claim 17, wherein forming the electrolyte comprises:

coating an electrolyte slurry onto at least part of the surface of the sintered first electrode, the electrode slurry comprising the solid-oxide electrolyte substance and a second solvent; and

drying and sintering the coated electrolyte.

20. The tubular solid-oxide electrochemical cell of claim 17, wherein forming the second electrode comprises:

coating an electrode slurry onto at least part of the surface of the electrolyte, the electrolyte slurry comprising the solid-oxide electrolyte substance, the second electrochemically active metallic substance, a second carbon-based pore forming substance, and a third solvent; and

drying and sintering the coated second electrode to cause the second carbon-based pore forming substance to burn off and form pores in the second electrode.

21. A process for manufacturing a tubular solid-oxide electrochemical cell, the process comprising:

forming an electrode dough comprising a solid-oxide electrolyte substance, a first electrochemically active substance, a first carbon-based pore forming substance, a first binder and a first solvent;

extruding the electrode dough in a tubular shape to form a first electrode;

sintering the extruded first electrode;

forming an electrolyte slurry comprising the solid-oxide electrolyte substance and a second solvent;

coating the electrolyte slurry onto at least part of a surface of the sintered first electrode;

sintering the electrolyte coating;

forming an electrode slurry comprising the solid-oxide electrolyte substance, a second electrochemically active substance, a second carbon-based pore forming substance, and a third solvent;

coating the electrode slurry onto at least part of a surface of the sintered electrolyte; and

sintering the electrode coating.

22. The process of claim 21, wherein forming the electrode dough comprises:

mixing and milling the solid-oxide electrolyte substance, the first electrochemically active substance, and the first carbon-based pore forming substance to form a milled mixture of ingredients;

drying the milled mixture of ingredients; and

adding the first binder and the first solvent into the dried milled mixture of ingredients.

23. The process of claim 21, wherein the electrode dough further comprises at least one component selected from the group consisting of:

a dispersant, a polymer, a cross-linker, an initiator, a catalyst, a plasticizer, a viscosity modifier, a flocculent, and a lubricant.

24. The process of claim 21, wherein the electrode dough comprises about 30% to about 70% by volume of solid ingredients.

25. The process of claim 21, wherein sintering the extruded first electrode comprises:

gradually heating to a set temperature between about 800°

C. to about 1600°

C.; and

holding at the set temperature for up to about 12 hours.

26. The process of claim 21, wherein the electrolyte slurry further comprises at least one component selected from the group consisting of:

a second binder, a dispersant, a polymer, a cross-linker, an initiator, a catalyst, and a plasticizer.

27. The process of claim 21, wherein the electrolyte slurry comprises about 10% to about 30% by volume of solid ingredients.

28. The process of claim 21, wherein the electrode slurry further comprises at least one component selected from the group consisting of:

a dispersant, a polymer, a cross-linker, an initiator, a catalyst, and a plasticizer.

29. The process of claim 21, wherein the electrode slurry comprises about 10% to about 30% by volume of solid ingredients.