Patent ID: 7846613

Claim:
A fuel cell formed by stacking a plurality of power generation cells in a stacking direction, said power generation cells each including a membrane electrode assembly and a pair of metal separators sandwiching said membrane electrode assembly, said membrane electrode assembly including a pair of electrodes and an electrolyte membrane interposed between said electrodes, wherein a reactant gas passage and a coolant passage extend through said power generation cells in a stacking direction, and a coolant flow field for supplying a coolant is formed between metal separators of adjacent power generation cells, and wherein at least one of said metal separators has a protrusion formed of a seal member on a first surface facing said membrane electrode assembly, a portion of the protrusion extends lengthwise on the first surface in a direction along a length of the at least one of said metal separators, the at least one of said metal separators has a ridge member made of a sealing material formed integrally on a second surface opposite to said membrane electrode assembly, said ridge member forms a connection channel connecting said coolant flow field and said coolant passage and said ridge member extends lengthwise on the second surface in a direction along a width of the at least one of said metal separators, the connection channel including a plurality of bifurcated grooves provided at least at opposite sides of the coolant passage between said coolant passage and said coolant flow field, and said ridge member overlaps with the portion of said protrusion in the stacking direction.