Unit cell for solid polymer electrolyte fuel cell

A solid polymer electrolyte fuel cell comprising a plurality of unit cells each having:

• a membrane/electrode assembly including a fuel electrode and an oxidant electrode disposed on either side of a solid polymer electrolyte membrane, the assembly being sandwiched from either side by a first separator and a second separator to give a stacked construction;
• a fuel gas flow passage formed between opposed faces of the fuel electrode and the first separator;
• and an oxidant gas flow passage formed between opposed faces of the oxidant electrode and the second separator, wherein the solid polymer electrolyte membrane in the membrane/electrode assembly has a planar shape slightly larger than the fuel electrode and the oxidant electrode so that an entire perimeter of an outer peripheral edge portion of the solid polymer electrolyte membrane forms a projecting portion projecting outwardly beyond outer peripheral edges of the fuel electrode and the oxidant electrode, and the projecting portion of the solid polymer electrolyte membrane is coated by a reinforcing resin member affixed thereto, wherein the first separator has a primary-face sealing rubber layer affixed onto a primary face thereof so that the reinforcing resin member is stacked on the first separator via the primary-face sealing rubber layer, and connecting grooves formed on the primary face thereof for connecting both ends of the fuel gas flow passage with a fuel gas feed/discharge ports respectively, which are formed perforating through the first separator, wherein the second separator has a primary-face sealing rubber layer affixed onto a primary face thereof so that the reinforcing resin member is stacked on the second separator via the primary-face sealing rubber layer, and connecting grooves formed on the primary face thereof for connecting both ends of the oxidant gas flow passage with an oxidant gas feed/discharge ports respectively, which are formed perforating through the second separator, and wherein the reinforcing resin member is placed so as to bridge openings of the connecting grooves in order to give a tunnel construction to the connecting grooves,
• wherein the unit cells are stacked in a sandwich direction of the first and second separators with respect to the membrane/electrode assembly.