Membrane electrode assembly, method for manufacturing the same, and fuel cell including the same

1. A membrane electrode assembly, including:

an electrolyte membrane;

an anode disposed on one face of said electrolyte membrane; and

a cathode disposed on the other face of said electrolyte membrane,

wherein said electrolyte membrane has a non-electrode-forming region where said cathode is not disposed thereon and an electrode-forming region where said cathode is disposed thereon,

wherein the non-electrode-forming region has a thin membrane region where the membrane is thinner than that in the electrode-forming region.

2. A membrane electrode assembly according to claim 1 , wherein a plurality of cells, each comprising said electrolyte membrane, said anode and said cathode, is formed in a planar arrangement, and

wherein the thin membrane regions are formed between cathodes of adjacent cells.

3. A membrane electrode assembly according to claim 1 , wherein the thin membrane region has a recess in a cathode-side surface of said electrolyte membrane.

4. A membrane electrode assembly according to claim 1 , wherein the thin membrane region has a groove surrounded by the electrode-forming region.

5. A membrane electrode assembly according to claim 4 , wherein the groove is formed linearly.

6. A membrane electrode assembly according to claim 4 , wherein the groove is formed in a bent shape.

7. A membrane electrode assembly according to claim 4 , wherein the groove is formed discontinuously.

8. A membrane electrode assembly according to claim 4 , wherein the groove is greater than or equal to 5 μm and less than or equal to 200 μm in width.

9. A membrane electrode assembly according to claim 1 , wherein the thin membrane region has a thickness of approximately 50% or more of the membrane thickness in the electrode-forming region and a thickness 5 μm or more thinner than the membrane thickness in the electrode-forming region.

10. A membrane electrode assembly according to claim 1 , wherein the ratio of an area of the thin membrane regions to that of the electrode-forming regions is in a range of greater than or equal to 0.01 and less than or equal to 0.1.

11. A membrane electrode assembly, including:

an electrolyte membrane;

an anode disposed on one face of said electrolyte membrane; and

a cathode disposed on the other face of said electrolyte membrane,

wherein said electrolyte membrane has a non-electrode-forming region where said cathode is not disposed thereon and an electrode-forming region where said cathode is disposed thereon, and

wherein in the non-electrode-forming region, said electrolyte membrane has a thin membrane region where the thin membrane is recessed lower than the surface of said electrolyte membrane in an adjacent electrode-forming region.

12. A fuel cell including a membrane electrode assembly according to claim 1 .

13. A method for manufacturing a membrane electrode assembly which includes: an electrolyte membrane; an anode disposed on one face of the electrolyte membrane; and a cathode disposed on the other face of the electrolyte membrane, wherein the electrolyte membrane has a non-electrode-forming region where the cathode is not disposed thereon and an electrode-forming region where the cathode is disposed thereon, the method including a thin membrane forming process in which a thin membrane region with a thickness thinner than that of the electrolyte membrane in the electrode-forming region and having an exposed surface is formed as part of the non-electrode-forming region.

14. A method, for manufacturing a membrane electrode assembly, according to claim 13 , wherein the thin membrane forming process includes a process for removing a surface layer of the electrolyte membrane together with the cathode or the anode, using laser.

15. A method, for manufacturing a membrane electrode assembly, according to claim 14 , wherein the oscillation wavelength of the laser is greater than or equal to 100 nm and less than or equal to 1100 nm.

16. A method, for manufacturing a membrane electrode assembly, according to claim 14 , wherein the oscillation wavelength of the laser is greater than or equal to 180 nm and less than or equal to 550 nm.

17. A method, for manufacturing a membrane electrode assembly, according to claim 14 , wherein the type of the laser is KrF excimer laser.