Patent ID: 8574781

Claim:
A fuel cell stack including power generation units stacked in a horizontal direction, each power generation unit formed by sandwiching an electrolyte electrode assembly between metal separators, the electrolyte electrode assembly including an anode, a cathode, and an electrolyte interposed between the anode and the cathode, the power generation units each having a corrugated fuel gas flow field including a plurality of corrugated flow grooves for supplying a fuel gas to the anode, the corrugated fuel gas flow field having a concave-convex shape in cross section, the plurality of corrugated flow grooves of the fuel gas flow field extending along a longitudinal direction of the separators, and a corrugated oxygen-containing gas flow field including a plurality of corrugated flow grooves for supplying an oxygen-containing gas to the cathode, the corrugated oxygen-containing gas flow field having a concave-convex shape in cross section, the plurality of corrugated flow grooves of the oxygen-containing gas flow field extending along the longitudinal direction of the separators, the power generation units including a first power generation unit and a second power generation unit stacked alternately such that a coolant flow field is formed between the first power generation unit and the second power generation unit, wherein the plurality of corrugated flow grooves of the fuel gas flow field and the plurality of corrugated flow grooves of the oxygen-containing gas flow field of the first power generation unit are in the same phase with each other; the plurality of corrugated flow grooves of the fuel gas flow field and the plurality of corrugated flow grooves of the oxygen-containing gas flow field of the second power generation unit are in the same phase with each other; and the plurality of corrugated flow grooves of the fuel gas flow field and the plurality of corrugated flow grooves of the oxygen-containing gas flow field of the first power generation unit and the plurality of corrugated flow grooves of the fuel gas flow field and the plurality of corrugated flow grooves of the oxygen-containing gas flow field of the second power generation unit are in different phases from each other, respectively.