主权项 |
1. A fuel cell stack comprising a first power generation unit and a second power generation unit, the first power generation unit and the second power generation unit each comprising a membrane electrode assembly and a metal separator being stacked, the membrane electrode assembly including an anode, a cathode, and an electrolyte membrane interposed between the anode and the cathode, a wavy fuel gas flow field including a plurality of flow grooves configured to allow a fuel gas to flow along an electrode surface of the anode in a wavy pattern and a wavy oxygen-containing gas flow field including a plurality of flow grooves configured to allow an oxygen-containing gas to flow along an electrode surface of the cathode in a wavy pattern being formed in each of the first power generation unit and the second power generation unit,
wherein, in the first power generation unit, the wavy fuel gas flow field and the wavy oxygen-containing gas flow field are in a same phase on both sides of the membrane electrode assembly; in the second power generation unit, the wavy fuel gas flow field and the wavy oxygen-containing gas flow field are in a same phase on both sides of the membrane electrode assembly, but the phase is different from the phase of the wavy fuel gas flow field and the wavy oxygen-containing gas flow field of the first power generation unit; the first power generation unit and the second power generation unit are stacked together to form a coolant flow field between a back surface of the wavy fuel gas flow field and a back surface of the wavy oxygen-containing gas flow field in the different phases from each other, configured to allow a coolant to flow through the coolant flow field; and at least one end of the wavy fuel gas flow field and at least one end of the wavy oxygen-containing gas flow field are terminated at a central portion of a width of amplitude of a waveform. |