Separator for fuel cell, manufacturing method thereof, and fuel cell having such a separator

A method for manufacturing a fuel cell having a separator for a fuel cell that is capable of closely contacting either an anode or a cathode of an MEA (membrane electrode assembly) of a fuel cell and interposing a fluid diffusion layer, the separator having a flow field channel for allowing a fluid to flow between the separator and the fluid diffusion layer, the method comprising:

• preparing a graphite foil of a predetermined size;
• forming a mask pattern on the graphite foil corresponding to the flow field channel;
• forming the flow field channel on the graphite foil by etching the graphite foil formed with the mask pattern thereon;
• forming a hydrophobic layer on an interior side of the flow field channel by impregnation;
• and
• removing the mask pattern from the graphite foil.

A fuel cell stack comprising at least one unit cell, wherein the at least one unit cell comprises:

• an MEA comprising a polymer electrolyte membrane, and an anode and a cathode formed on both sides thereof;
• a pair of fluid diffusion layers contiguously disposed to the anode and the cathode at both sides of the MEA;
• and
• a pair of separators for closely contacting the pair of fluid diffusion layers, forming flow field channels on sides thereof facing the fluid diffusion layers so as to form a reaction region, and forming manifold regions peripheral to the reaction region,
• wherein at least one of the pair of separators comprises a lamellar structure graphite foil, and a hydrophobic layer is formed by impregnation on an interior side of the flow field channels of the at least one of the pair of separators.