Patent ID: 7691511

Claim:
A fuel cell formed by stacking electrolyte electrode assemblies and separators alternately in a stacking direction, said electrolyte electrode assemblies each including a pair of electrodes and an electrolyte interposed between said electrodes, wherein a reactant gas flow field for supplying a reactant gas is formed between said electrode electrolyte assembly and one of said separators sandwiching said electrolyte electrode assembly, for supplying a reactant gas along a surface of said electrode, and a coolant flow field is formed between adjacent separators which are stacked together for allowing a coolant to flow in a direction substantially perpendicular to a flow direction of the reactant gas, and wherein a reactant gas supply passage and a reactant gas discharge passage for said reactant gas flow field extend through said fuel cell in the stacking direction, and further wherein: said one separator includes an inlet buffer connecting said reactant gas supply passage and said reactant gas flow field, and an outlet buffer connecting said reactant gas discharge passage and said reactant gas flow field; and said coolant flow field comprises a flow field wall disposed between said adjacent separators for preventing the coolant from flowing into an area corresponding to said inlet buffer, while allowing the coolant to flow into an area corresponding to said outlet buffer, said flow field wall disposed immediately adjacent to and surrounding an area corresponding to said inlet buffer.