A fuel cell separator includes a coolant flow field formed between first and second metal separator plates. A first communication hole is formed in an outer peripheral wall of each of passage sealing beads that surround respectively an air vent passage and a coolant drain passage which are formed so as to penetrate in a separator thickness direction. A second communication hole is formed in an inner peripheral wall of each of the passage sealing beads. The first communication hole and the second communication hole are positioned to be displaced from each other in an extending direction of a first internal channel or a second internal channel.

A fuel cell separator includes a coolant flow field formed between first and second metal separator plates. A first communication hole is formed in an outer peripheral wall of each of passage sealing beads that surround respectively an air vent passage and a coolant drain passage which are formed so as to penetrate in a separator thickness direction. A second communication hole is formed in an inner peripheral wall of each of the passage sealing beads. The first communication hole and the second communication hole are positioned to be displaced from each other in an extending direction of a first internal channel or a second internal channel.

A fuel cell system includes a first electrically non-conductive sheet portion having a coolant flow layer in an opening thereof, a first non-stamped, flat, metal separator on a first side of the coolant flow layer and a second non-stamped, flat, metal separator on a second side of the coolant flow layer opposite the first separator. A membrane is received in an opening of a second electrically non-conductive sheet portion. Gas diffusion layers are located on opposite sides of the membrane. The gas diffusion layers have channels open toward the first non-stamped, flat, metal separator or the second non-stamped, flat, metal separator to allow flow of an oxidant and/or fuel therethrough.

A fuel cell system includes a first electrically non-conductive sheet portion having a coolant flow layer in an opening thereof, a first non-stamped, flat, metal separator on a first side of the coolant flow layer and a second non-stamped, flat, metal separator on a second side of the coolant flow layer opposite the first separator. A membrane is received in an opening of a second electrically non-conductive sheet portion. Gas diffusion layers are located on opposite sides of the membrane. The gas diffusion layers have channels open toward the first non-stamped, flat, metal separator or the second non-stamped, flat, metal separator to allow flow of an oxidant and/or fuel therethrough.

An electrochemical device comprises a stack consisting of a plurality of electrochemical units which succeed one another along a stack direction and which each include a membrane electrode arrangement, a bipolar plate and at least one sealing element, at least one medium channel which extends along the stack direction, a flow field through which a medium can flow from the medium channel to another medium channel, and a connection channel through which the flow field and the medium channel are in fluid connection with one another, wherein the sealing arrangement includes a connection channel region in which the sealing arrangement crosses the connection channel, and at least one neighboring region which is located in front of or behind the connection channel region in the longitudinal direction of the sealing arrangement, wherein the sealing arrangement has a lower average height in the connection channel region than in the neighboring region.

An electrochemical device comprises a stack consisting of a plurality of electrochemical units which succeed one another along a stack direction and which each include a membrane electrode arrangement, a bipolar plate and at least one sealing element, at least one medium channel which extends along the stack direction, a flow field through which a medium can flow from the medium channel to another medium channel, and a connection channel through which the flow field and the medium channel are in fluid connection with one another, wherein the sealing arrangement includes a connection channel region in which the sealing arrangement crosses the connection channel, and at least one neighboring region which is located in front of or behind the connection channel region in the longitudinal direction of the sealing arrangement, wherein the sealing arrangement has a lower average height in the connection channel region than in the neighboring region.

A bead-type separator for a fuel cell includes a reaction surface disposed at a center of the separator and for reacting a flowing reaction gas, a diffusion part disposed at both sides of the reaction surface for diffusing the reaction gas, multiple manifold through-holes disposed in regions at both ends of the separator and introducing or discharging the reaction gas, and multiple protruding inner bead seals along a periphery of the regions in which the manifold through-holes are disposed, wherein the inner bead seals comprise a first inner bead seal disposed at the periphery of the region in which the manifold through-hole configured to discharge the reaction gas is formed, and wherein the first inner bead seal includes multiple main discharge bead flow fields protruding in tunnel shapes from a diffusion part and multiple main connection bead flow fields.

A bead-type separator for a fuel cell includes a reaction surface disposed at a center of the separator and for reacting a flowing reaction gas, a diffusion part disposed at both sides of the reaction surface for diffusing the reaction gas, multiple manifold through-holes disposed in regions at both ends of the separator and introducing or discharging the reaction gas, and multiple protruding inner bead seals along a periphery of the regions in which the manifold through-holes are disposed, wherein the inner bead seals comprise a first inner bead seal disposed at the periphery of the region in which the manifold through-hole configured to discharge the reaction gas is formed, and wherein the first inner bead seal includes multiple main discharge bead flow fields protruding in tunnel shapes from a diffusion part and multiple main connection bead flow fields.

The present disclosure generally relates to systems and methods for inducing a secondary flow from a first groove in a bipolar plate of a fuel cell to a second groove in the bipolar plate over a first land in the bipolar plate wherein the land is adjacent to a compressed section of a gas diffusion layer in the fuel cell, and wherein the secondary flow increases locally available oxygen and hydrogen at the membrane electrode assembly adjacent to the compressed section of the gas diffusion layer.

The present disclosure generally relates to systems and methods for inducing a secondary flow from a first groove in a bipolar plate of a fuel cell to a second groove in the bipolar plate over a first land in the bipolar plate wherein the land is adjacent to a compressed section of a gas diffusion layer in the fuel cell, and wherein the secondary flow increases locally available oxygen and hydrogen at the membrane electrode assembly adjacent to the compressed section of the gas diffusion layer.