In order to provide a membrane electrode assembly that can further improve power generation performances of a fuel cell, the present invention allows a rib portion (22) that separates mutually adjacent gas flow passages (21) from each other to have a porosity lower than the porosity of a lower area (23) of the rib portion. Thus, it is possible to suppress the deformation of the rib portion and excessive permeation of a reaction gas, and consequently to further improve the power generation performances.

A fuel cell gas supply and diffusion layer includes a sheet-like porous body layer, and a plurality of gas passage grooves formed on one surface of the porous body layer in parallel and formed in a zigzag shape or a wave shape respectively. As viewed in a plan view, a first rectangular region where circumscribes one gas passage groove and a second rectangular region where circumscribes a gas passage groove adjacent to the one gas passage groove overlap along a region in contact each other. An overlapping region where the first rectangular region and the second rectangular region overlap exists at any depth position of the grooves. According to the fuel cell gas supply and diffusion layer, it is possible to increase a power generation efficiency of a fuel cell.

A fuel cell gas supply and diffusion layer includes a sheet-like porous body layer, and a plurality of gas passage grooves formed on one surface of the porous body layer in parallel and formed in a zigzag shape or a wave shape respectively. As viewed in a plan view, a first rectangular region where circumscribes one gas passage groove and a second rectangular region where circumscribes a gas passage groove adjacent to the one gas passage groove overlap along a region in contact each other. An overlapping region where the first rectangular region and the second rectangular region overlap exists at any depth position of the grooves. According to the fuel cell gas supply and diffusion layer, it is possible to increase a power generation efficiency of a fuel cell.

A fuel cell separator capable of surely discharging produced water, and a method and apparatus for producing the same. The fuel cell separator is formed in a wave shape with recesses and projections alternately arranged in a first direction, the recesses forming reactant gas channels together with a membrane electrode assembly and the projections abutting the membrane electrode assembly, in which on a surface of the fuel cell separator that is adapted to face the membrane electrode assembly, a plurality of first grooves extending in the first direction along the corrugation of the recesses and projections is disposed at intervals from each other in a second direction orthogonal to the first direction, and a second groove extending in the second direction and communicating with the plurality of first grooves is disposed in the bottom portion of each recess.

A fuel cell separator capable of surely discharging produced water, and a method and apparatus for producing the same. The fuel cell separator is formed in a wave shape with recesses and projections alternately arranged in a first direction, the recesses forming reactant gas channels together with a membrane electrode assembly and the projections abutting the membrane electrode assembly, in which on a surface of the fuel cell separator that is adapted to face the membrane electrode assembly, a plurality of first grooves extending in the first direction along the corrugation of the recesses and projections is disposed at intervals from each other in a second direction orthogonal to the first direction, and a second groove extending in the second direction and communicating with the plurality of first grooves is disposed in the bottom portion of each recess.

A fuel cell stack includes a membrane electrode assembly and a bipolar plate. The bipolar plate has a corrugated portion defined by an adjacent pair of proximal and distal peak portions and a sidewall segment connecting the peak portions. The sidewall segment and membrane electrode assembly at least partially define a flow channel. The sidewall segment includes a shoulder portion defining a step spaced away from the peak portions.

A fluid flow guide plate for an electrochemical reactor. The plate includes, on a single surface: a flow collector; a plurality of flow channels, provided on the plate to ensure fluid flow and extending in a single longitudinal direction; an exchange channel, extending in a direction transverse to the flow channels; a plurality of supply channels that are fluidly connected, on a first side, to the flow collector by a first end and, on a second side, to the exchange channel by a second end. The exchange channel puts the flow channels in communication with one another and includes at least one obstacle provided to partially close off the flow between the second ends and the flow channels.

A unit cell of a fuel cell includes a membrane electrode assembly and a cathode side separator and an anode side separator sandwiching the membrane electrode assembly. An oxygen-containing gas supply passage connected to an oxygen-containing gas flow field is formed in the cathode side separator. The oxygen-containing gas supply passage has a rectangular shape extending in a flow field width direction of the oxygen-containing gas flow field. The width of the opening of the oxygen-containing gas supply passage on the short side is increased from the end side to the central side in the flow field width direction.

A unit cell of a fuel cell includes a membrane electrode assembly and a cathode side separator and an anode side separator sandwiching the membrane electrode assembly. An oxygen-containing gas supply passage connected to an oxygen-containing gas flow field is formed in the cathode side separator. The oxygen-containing gas supply passage has a rectangular shape extending in a flow field width direction of the oxygen-containing gas flow field. The width of the opening of the oxygen-containing gas supply passage on the short side is increased from the end side to the central side in the flow field width direction.

Disclosed is a method for dynamic variable humidity control; wherein the flow rate of the working gas flow is changed repeatedly according to a certain time interval and increment.