A fuel cell system includes a first fluid flow plate including a first plurality of first channels for flow of an oxidant or a fuel. The plurality of first channel has first channel cross-sectional flow areas. A second fluid flow plate includes a second plurality of second channels for flow of an oxidant or a fuel. The plurality of second channels has second channel cross-sectional flow areas. A membrane electrode assembly is located between the first plate and the second plate. The first flow plate includes a passage for a flow of a fluid entirely on a seam side of the first flow plate as the first plurality of first channels. The passage has a cross-sectional area for flow of the fluid smaller than the first channel cross-sectional flow area.

A bipolar plate is provided including an outlet port and an inlet port with at least one flow field having a plurality of ducts connecting the inlet port to the outlet port, and with at least one bypass duct at a side of the at least one flow field. A flow resistance in the at least one bypass duct is determined by the design of the at least one bypass duct. A blocking element does not project into a cross section of the at least one bypass duct.

A bipolar plate is provided including an outlet port and an inlet port with at least one flow field having a plurality of ducts connecting the inlet port to the outlet port, and with at least one bypass duct at a side of the at least one flow field. A flow resistance in the at least one bypass duct is determined by the design of the at least one bypass duct. A blocking element does not project into a cross section of the at least one bypass duct.

The present invention relates to a separator plate for an electro-chemical system. The separator plate comprises: a first passage; an active region with structures for guiding a reaction medium along a first flat face of the separator plate and guiding a coolant along a rear face of the active region on the second flat face of the separator plate; a bead formed in the separator plate for sealing at least the active region; and barrier elements formed in the separator plate, which reduce or prevent a flow of reaction medium on the first flat face of the separator plate along the bead and past the active region. The separator plate fully encloses the first passage and the active region together and that at least one of the barrier elements is at least in parts sunk.

The present invention relates to a separator plate for an electro-chemical system. The separator plate comprises: a first passage; an active region with structures for guiding a reaction medium along a first flat face of the separator plate and guiding a coolant along a rear face of the active region on the second flat face of the separator plate; a bead formed in the separator plate for sealing at least the active region; and barrier elements formed in the separator plate, which reduce or prevent a flow of reaction medium on the first flat face of the separator plate along the bead and past the active region. The separator plate fully encloses the first passage and the active region together and that at least one of the barrier elements is at least in parts sunk.

A bipolar plate for a fuel cell includes a corrugated plate and a second plate, which is arranged on the corrugated plate in a sealing manner. The corrugated plate has a wave pattern of ascending and descending waves. The corrugated plate has a hole pattern with between one and three parallel rows arranged to for the passage of a gas substantially transversely to the wave shape. Hole sizes and shaped in these three rows are selected in specified relationships to optimize the fuel cell performance.

A bipolar plate for a fuel cell includes a corrugated plate and a second plate, which is arranged on the corrugated plate in a sealing manner. The corrugated plate has a wave pattern of ascending and descending waves. The corrugated plate has a hole pattern with between one and three parallel rows arranged to for the passage of a gas substantially transversely to the wave shape. Hole sizes and shaped in these three rows are selected in specified relationships to optimize the fuel cell performance.

An oxygen-containing gas flow field and an inner bead (or a bead seal) are formed on one surface of a first metal separator, and a coolant flow field as a passage of a coolant is formed on the other surface of the first metal separator. Further, a coolant supply passage and a coolant discharge passage extend through the first metal separator in a separator thickness direction. An in-bead channel as a passage of the coolant is formed by a recess on the back side of the inner bead. A narrowed segment is provided in a part of the in-bead channel. The channel cross sectional area of the narrowed segment is smaller than those of other segments.

An oxygen-containing gas flow field and an inner bead (or a bead seal) are formed on one surface of a first metal separator, and a coolant flow field as a passage of a coolant is formed on the other surface of the first metal separator. Further, a coolant supply passage and a coolant discharge passage extend through the first metal separator in a separator thickness direction. An in-bead channel as a passage of the coolant is formed by a recess on the back side of the inner bead. A narrowed segment is provided in a part of the in-bead channel. The channel cross sectional area of the narrowed segment is smaller than those of other segments.

In a flange in the form of a flat plate inside a bead seal (e.g., fluid passage bead) around a fluid passage (e.g., an oxygen-containing gas supply passage) of a fuel cell metal separator (e.g., a first metal separator), a tunnel is provided in a straight segment adjacent to a curved segment of an inner marginal portion of the flange. The tunnel is formed by expansion in a separator thickness direction.