Patent ID: 7824818

Claim:
A fuel cell stack in which unit cells, each of which is made up of an electrolyte layer plus a fuel electrode and an oxygen electrode that are provided on opposite sides of the electrolyte layer, are stacked such that they sandwich a separator to form, between the oxygen electrodes, an oxidizing gas chamber to which a mixed flow of air and water is supplied, wherein the oxidizing gas chamber has an inlet port in an upper portion for the mixed flow and an outlet port in a lower portion for the mixed flow; the separator has a collector member that is in contact with the oxygen electrode and is in the form of a mesh with openings extending therethrough; the collector member forms a plurality of air flow channels with hydrophilic inner wall surfaces; and the outlet port has a projecting portion including a hydrophilic upper part which receives water from the hydrophilic inner wall surfaces of the air flow channels and a water repellant lower part beneath the hydrophilic upper part.