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.

A film-integrated gasket is provided in which a gasket body is supported by a gasket support body formed of a resin film and a film thickness t.sub.2 at a position where the gasket body is supported is set to be smaller than a film thickness t.sub.1 at an adjacent position thereto so as to satisfy a demand for low reaction force by reducing the compression ratio in the thickness directional in mounting. The film-integrated gasket can be provided with a portion compressed in the thickness direction at the position where the gasket body is supported, so that the portion sets a thickness difference. The film-integrated gasket can alternatively be provided with a portion where a plurality of resin films is stacked at an adjacent position to the position where the gasket main body is supported, so that the portion sets a thickness difference.

A film-integrated gasket is provided in which a gasket body is supported by a gasket support body formed of a resin film and a film thickness t.sub.2 at a position where the gasket body is supported is set to be smaller than a film thickness t.sub.1 at an adjacent position thereto so as to satisfy a demand for low reaction force by reducing the compression ratio in the thickness directional in mounting. The film-integrated gasket can be provided with a portion compressed in the thickness direction at the position where the gasket body is supported, so that the portion sets a thickness difference. The film-integrated gasket can alternatively be provided with a portion where a plurality of resin films is stacked at an adjacent position to the position where the gasket main body is supported, so that the portion sets a thickness difference.

In order to create an electrochemical device, comprising a plurality of electrochemical units, which succeed one another along a stack direction, wherein each electrochemical unit comprises a bipolar plate and an electrically insulating seal, and a clamping device for clamping the electrochemical units along the stack direction, in which electrochemical device the risk of a short circuit between adjacent bipolar plates is reduced without the expenditure for the production of the electrochemical device being excessively increased, it is proposed that at least one seal of at least one electrochemical unit in the pressed state protrudes laterally beyond a contour of the bipolar plate of the electrochemical unit in a direction of protrusion directed perpendicularly to the stack direction.

The bipolar separator is formed by the superimposition of two distribution plates and two cooling plates, the two cooling plates being arranged between the two distribution plates, each distribution plate having an outer face and an inner face, the outer face of each distribution plate being provided with distribution channels for the flow of a reactive fluid, the cooling plates defining internal conduits for the circulation of a cooling fluid.

The bipolar separator is formed by the superimposition of two distribution plates and two cooling plates, the two cooling plates being arranged between the two distribution plates, each distribution plate having an outer face and an inner face, the outer face of each distribution plate being provided with distribution channels for the flow of a reactive fluid, the cooling plates defining internal conduits for the circulation of a cooling fluid.

A separator plate arrangement for an electrochemical system, comprising a first metal sheet and a second metal sheet. The first metal sheet has a first circumferential sealing structure for sealing off an electrochemically active region, a first cutout arranged outside of the first circumferential sealing structure, and a first embossed structure arranged outside of the first circumferential sealing structure. The second metal sheet has a second circumferential sealing structure for sealing off an electrochemically active region, a second cutout arranged outside of the second circumferential sealing structure, and a second embossed structure arranged outside of the second circumferential sealing structure.

A fuel cell stack comprising stacked unit cells, each comprising a membrane electrode assembly comprising an electrolyte membrane and a pair of electrodes disposed on both surfaces thereof, two separators sandwiching the membrane electrode assembly, and a frame-shaped resin sheet disposed between the two separators and around the membrane electrode assembly to attach the separators, wherein the resin sheet comprises a first protrusion protruding in the planar direction of the resin sheet and occupying a part of a first region occupied by a reaction gas inlet manifold, and a second protrusion protruding in the planar direction of the resin sheet and occupying a part of a second region occupied by a reaction gas outlet manifold; and wherein the resin sheet comprises at least one water discharge hole at a predetermined position of at least one protrusion selected from the group consisting of the first protrusion and the second protrusion.