MEMBRANE-ELECTRODE ASSEMBLY FOR FUEL CELL AND FUEL CELL SYSTEM INCLUDING SAME

Abstract

A membrane-electrode assembly includes a polymer electrolyte membrane, and a cathode and an anode disposed on each side of a polymer electrolyte membrane. The anode includes a catalyst layer contacted with the polymer electrolyte membrane and an electrode substrate disposed the other surface of the catalyst layer. The electrode substrate includes a first surface contacted with the catalyst layer and a second surface not contacted with the catalyst layer, and the first surface is hydrophilic. Or, the electrode substrate includes a first electrode substrate contacted with the catalyst layer, and a second electrode substrate disposed to contact with the first electrode substrate wherein the first electrode substrate is hydrophilic.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a schematic cross-sectional view showing a membrane-electrode assembly according to aspects of the present invention.

FIG. 2 is a schematic cross-sectional view showing a membrane-electrode assembly according to aspects of the present invention.

FIG. 3A to 3D are views showing contact angles with respect to a substrate.

FIG. 4 schematically shows the structure of a fuel cell system according aspects of the present invention.

FIG. 5 shows voltages and current density of single cells according Example 1 and Comparative Example 1.

Claims

1. A membrane-electrode assembly for a fuel cell comprising: a polymer electrolyte membrane; anda cathode and an anode disposed at respective sides of the polymer electrolyte membrane,wherein the anode comprises a catalyst layer having a first surface disposed to contact the polymer electrolyte membrane and an electrode substrate disposed on a second surface of the catalyst layer, wherein the electrode substrate comprises a first surface disposed to contact the second surface of the catalyst layer and a second surface disposed not to contact the catalyst layer, andthe first surface is hydrophilic.

2. The membrane-electrode assembly for a fuel cell of claim 1, wherein the hydrophilicity increases from the second surface of the electrode substrate to the first surface of the electrode substrate.

3. The membrane-electrode assembly for a fuel cell of claim 1, wherein the contact angle of the first surface of the electrode substrate is at or between about 0 and 40°, and the contact angle of the second surface of the electrode substrate is at or between about 40 and 80°.

4. The membrane-electrode assembly for a fuel cell of claim 3, wherein the contact angle of the first surface of the electrode substrate is at or between about 0 and 15°, and the contact angle of the second surface of the electrode substrate is at or between about 40 and 60°.

5. The membrane-electrode assembly for a fuel cell of claim 1, wherein the first surface of the electrode substrate includes at least one element selected from the group consisting of O2, argon, N2, and a mixture thereof.

6. The membrane-electrode assembly for a fuel cell of claim 1, wherein the electrode substrate is a plasma-treated electrode substrate provided by being subjected to a plasma treatment in which the first surface of the electrode substrate is exposed to a plasma and the second surface of the electrode substrate is masked.

7. A membrane-electrode assembly for a fuel cell comprising: a polymer electrolyte membrane; anda cathode and an anode disposed at respective sides of the polymer electrolyte membrane,wherein the anode comprises a catalyst layer having a first surface disposed to contact the polymer electrolyte membrane and an electrode substrate disposed on a second surface of the catalyst layer, wherein the electrode substrate comprises a first electrode substrate having a first surface disposed to contact the second surface of the catalyst layer and a second electrode substrate having a first surface disposed to contact the second surface of the first electrode substrate, andthe first electrode substrate is hydrophilic.

8. The membrane-electrode assembly for a fuel cell of claim 7, wherein the contact angle of the first surface of the first electrode substrate is between about 0 and 40°, and the contact angle of the second surface of the second electrode substrate is at or between about 40 and 80°.

9. The membrane-electrode assembly for a fuel cell of claim 8, wherein the contact angle of the first surface of the first electrode substrate is at or between about 0 and 15° and the contact angle of the second surface of the second electrode substrate is at or between about 40 and 60°.

10. The membrane-electrode assembly for a fuel cell of claim 7, wherein the first surface of the first electrode substrate includes at least one element selected from the group consisting of O2, argon, N2 and a mixture thereof.

11. The membrane-electrode assembly for a fuel cell of claim 7, wherein the first electrode substrate is a plasma-treated electrode substrate provided by subjecting the first electrode substrate to a plasma treatment in which the first surface of the first electrode substrate is exposed to a plasma.

12. A method of fabricating a membrane-electrode assembly comprising: introducing an electrode substrate into a plasma chamber;subjecting a first surface of the electrode substrate to a plasma,disposing the first surface of the electrode substrate to contact a catalyst layer.

13. A fuel cell system comprising: at least one electricity generating element to generate electricity through oxidation of a fuel and reduction of an oxidant and comprising an electrode-membrane assembly comprisingan anode and a cathode facing each other, anda polymer electrolyte membrane disposed between the anode and the cathode, anda separator;a fuel supplier to supply the fuel to the electricity generating element; andan oxidant supplier to supply the oxidant to the electricity generating element,wherein the anode comprises a catalyst layer having a first surface disposed to contact the polymer electrolyte membrane and an electrode substrate having a first surface disposed to contact a second surface of the catalyst layer, whereinthe electrode substrate comprises a first surface disposed to contact the second surface of the catalyst layer and a second surface disposed not to contact the catalyst layer, andthe first surface of the electrode substrate is hydrophilic.

14. The fuel cell system of claim 13, wherein the hydrophilicity increases from the second surface of the electrode substrate to the first surface of the electrode substrate.

15. The fuel cell system of claim 13, wherein the contact angle of the first surface of the electrode substrate is at or between about 0 and 40°, and the contact angle of the second surface of the electrodes substrate is at or between about 40 and 80°.

16. The fuel cell system of claim 151 wherein the contact angle of the first surface of the electrode substrate is at or between about 0 and 15°, and the contact angle of the second surface of the electrodes substrate is at or between about 40 and 60°.

17. The fuel cell system of claim 13, wherein the first surface of the electrode substrate includes at least one element selected from the group consisting of O2, argon, N2, and a mixture thereof.

18. A fuel cell system comprising: at least one electricity generating element adopted to generate electricity through oxidation of a fuel and reduction of an oxidant and comprising: an electrode-membrane assembly comprising: an anode and a cathode facing each other, anda polymer electrolyte membrane disposed between the anode and the cathode, anda separator;a fuel supplier adopted to supply the fuel to the electricity generating element; andan oxidant supplier adopted to supply the oxidant to the electricity generating element,wherein the anode comprises a catalyst layer having a first surface disposed to contact the polymer electrolyte membrane and an electrode substrate disposed on a second surface of the catalyst layer,wherein the electrode substrate comprises a first electrode substrate having a first surface disposed to contact the second surface of the catalyst layer and a second electrode having a first surface disposed to contact with the second surface of the first electrode substrate, andthe first electrode substrate is hydrophilic.

19. The fuel cell system of claim 18, wherein the contact angle of the first surface of the first electrode substrate is at or between about 0 and 40°, and the contact angle of the second surface of the second electrode is at or between about 40 and 80°.

20. The fuel cell system of claim 19, wherein the contact angle of the first surface of the first electrode substrate is at or between about 0 and 15°, and the contact angle of the second surface of the second electrode substrate is at or between about 40 and 60°.

21. The fuel cell system of claim 18, wherein the first surface of the first electrode substrate includes at least one element selected from the group consisting of O2, argon, N2 and a mixture thereof.

22. The method of claim 12, further comprising: masking a second surface of the electrode substrate to protect the second surface from being exposed to the plasma.

23. The method of claim 12, further comprising: creating gas atmosphere of Ar, N2, O2, or a mixture thereof in the plasma chamber.

24. The method of claim 12, further comprising: providing electrical power to the electrode substrate.

25. The method of claim 24, wherein the electrical power is provided at about 100 to 300 W.

26. The method of claim 12, further comprising: subjecting first surfaces of a plurality of electrode substrates to a plasma.

27. The method of claim 26, further comprising: disposing the first surface of an electrode substrate of the plurality of electrode substrates having a highest hydrophilicity to contact the catalyst layer, andarranging the plurality of electrode substrates from a lowest hydrophilicity to the highest hydrophilicity in a direction toward the catalyst layer.

28. The method of claim 12, wherein the electrode substrate further comprises: a plurality of electrode substrate layers,wherein a first surface of a first electrode substrate layer of the plurality of electrode substrate layers is the first surface of the electrode substrate.

29. A method of fabricating a membrane-electrode assembly, the method comprising: forming an anode to have a catalyst layer disposed on an electrode substrate, wherein the electrode substrate comprises: a first surface and a second surface, and the first surface of the electrode substrate has a higher hydrophilicity than the second surface of the electrode substrate;forming a cathode; anddisposing an electrolyte between the anode and the cathode so that the catalyst layer contacts the electrolyte.

30. The method of claim 29, wherein the method further comprises: disposing the catalyst layer on the first surface of the electrode substrate.

31. The method of claim 29, wherein the electrode substrate further comprises: a plurality of electrode substrate layers of differing hydrophilicities, wherein a first surface of a first electrode substrate layer of the plurality of electrode substrate layers having a highest hydrophilicity is the first surface of the electrode substrate, andthe method further comprising: arranging the plurality of electrode substrate layers in order of a lowest hydrophilicity to the highest hydrophilicity in a direction toward the catalyst layer; anddisposing the catalyst layer on the first surface of the electrode substrate.

32. A method of fabricating an anode for a fuel cell, comprising: forming an anode catalyst composition;forming an electrode substrate having a first surface and a second surface, wherein the first surface is more hydrophilic than the second surface; anddisposing the anode catalyst composition on the first surface of the electrode substrate.

33. The method of claim 32, wherein the electrode substrate further comprises: a plurality of electrode substrate layers of differing hydrophilicities, wherein a first surface of a first electrode substrate layer of the plurality of electrode substrate layers having a highest hydrophilicity is the first surface of the electrode substrate, andthe method further comprising: arranging the plurality of electrode substrate layers in order of a lowest hydrophilicity to the highest hydrophilicity in a direction toward the catalyst layer.

34. An anode for a fuel cell, comprising: a catalyst layer having a catalyst surface;an electrode substrate having a first surface and a second surface;wherein the first surface of the electrode substrate is more hydrophilic than the second surface of the electrode substrate.

35. The anode of claim 34, wherein the first surface of the electrode substrate contacts the catalyst surface.

36. The anode of claim 34, wherein the electrode substrate comprises: a plurality of electrode substrate layers,wherein each of the electrode substrate layers has a different hydrophilicity.

37. The anode of claim 36, wherein an electrode substrate layer with a highest hydrophilicity contacts the catalyst surface.

38. The anode of claim 37, wherein the plurality of electrode substrate layers are arranged from the lowest hydrophilicity to the highest hydrophilicity in a direction toward the catalyst layer.

39. A membrane-electrode assembly, comprising: the anode of claim 34.

40. A fuel cell system, comprising: a plurality of unit fuel cells each including the membrane-electrode assembly of claim 39.