Abstract: A method for laser-based deep welding of at least two parts to be joined, in which a laser beam device generates a laser beam with a deep welding laser beam component, which is moved at a feed rate along a joint. The deep welding laser beam component generates a vapor capillary in the material of the parts to be joined, which capillary is surrounded by a melt pool and which moves with the laser beam in the welding direction through the material of the parts to be joined, forming a capillary flow, in which a metal melt located at the capillary front flows via melt pool channels formed on both sides of the vapor capillary in the direction of the capillary rear side and solidifies there.

Abstract: A fuel cell device is provided comprising a fuel cell stack, which is formed from a plurality of unit cells which are stacked one above the other in a stacking direction and which each have one or more media channels and a membrane electrode assembly, which comprises a cathode, an anode and a membrane arranged between the cathode and the anode, as well as comprising a media guide extending essentially in parallel to the stacking direction. The media guide can be or is connected to the fuel cell stack in such a way as to guide a medium essentially laterally to the stacking direction into or out of the media channels of the unit cells of the fuel cell stack.

Abstract: A method for laser beam joining of at least two joining partners, in which a laser beam device produces a continuous weld seam along an application path with a preferably very long path length. Irregularities in the weld seam due to high process speeds are avoided as follows: in a first process step, at least two weld seam sections spaced apart from one another in the longitudinal direction of the path, are respectively produced with an intermediate weld seam interruption. In a second process step the laser beam device produces in each weld seam interruption a further weld seam section, such that all weld seam sections merge together without interruptions, in particular with formation of the continuous weld seam.

Abstract: A fuel cell stack is provided comprising a plurality of fuel cells stacked on top of one another along a stacking direction. At least one of the fuel cells comprises at least one compressible fabric structure, having a spring function with a spring constant. With the spring function, a change in length of the fuel cell along the stacking direction can be equalized by an opposite and negative change in length of the compressible fabric structure.

Abstract: A method for producing a bipolar plate strand comprises: providing of the unipolar plate strands; moving of the unipolar plate strands in the direction of a roll gap of a roll pair provided with roll structures of a rolling device; sending of a laser beam of a laser device onto a rotating mirrored polygon wheel, so that the laser beam is directed at a plurality of individual positions of a surface of one or both of the unipolar plate strands and the individual positions are thus heated to a joining temperature immediately before or upon entry of the unipolar plate strands in the roll gap; and joining of the unipolar plate strands at least at one of the individual positions of the surface to form a bipolar plate strand upon transporting of the unipolar plate strands through the roll gap under the action of pressure. A method for production of a bipolar plate as well as a device to implement the method are also provided.

Abstract: A bipolar plate for a fuel cell is provided having an active region and a marginal region surrounding the active region, and having a first media guide having a first passage and a second media guide having a second passage, and having a media duct extending through the active region and fluidically connecting the first passage to the second passage, wherein the first passage and/or the second passage is associated with a diaphragm, which is adjustable by an actuator to establish or to regulate the flow cross section of the first passage and/or of the second passage. A fuel cell stack having a fuel cell with such a bipolar plate is also provided.

Abstract: A method for joining at least two components of a fuel cell, especially for joining two single plates of a fuel cell to make a bipolar plate, comprises: providing a first component of the fuel cell and providing at least one second component of the fuel cell; and directing a pulsed laser beam of a laser apparatus onto a rotating mirrored polygon wheel, by which the laser beam forms a joint line consisting of a plurality of overlapping pointlike and/or line-shaped joining locations on the components. A device for carrying out the method is also provided.

Abstract: A fuel cell device is provided comprising a fuel cell stack which is formed from a plurality of unit cells stacked one above the other in a stacking direction, each unit cell having one or more media channels and a membrane electrode assembly that comprises a cathode, an anode and a membrane arranged between the cathode and the anode, and comprising a media duct running substantially parallel to the stacking direction. The media duct is connected or can be connected to the fuel cell stack to conduct a medium into or out of the media channels of the unit cells of the fuel cell stack substantially laterally to the stacking direction, and comprises duct flanges that are connected at least indirectly to each other and can be connected or are connected to the fuel cell stack. The duct flanges of the media duct are inserted into flange receptacles of the fuel cell stack running substantially parallel to the stacking direction.

Abstract: A bipolar plate for a fuel cell comprises an active region and an edge region surrounding the active region, the edge region being associated to a first media guide fluidically connected to a first passage and a second media guide fluidically connected to a second passage, as well as having a media duct which runs through the active region and fluidically connects the first passage to the second passage. At least one of the media guides comprises a first partial chamber and a second partial chamber having the passage. A flow cross-section of the media guide is tapered between the first partial chamber and the second partial chamber., and a diaphragm can be inserted or is inserted into the second partial chamber.

Abstract: A fuel cell device comprises a fuel cell stack which is formed from a plurality of unit cells stacked one above the other in a stacking direction, each unit cell having one or more media channels and a membrane electrode assembly that comprises a cathode, an anode, and a membrane arranged between the cathode and the anode, and comprising a media duct running substantially parallel to the stacking direction. The media duct is connected or can be connected to the fuel cell stack to conduct a medium into or out of the media channels of the unit cells of the fuel cell stack substantially laterally to the stacking direction. The media duct is formed as a functional component or such a functional component is integrated therein, which is formed to pre-treat the medium before it enters the media channels or to post-treat the medium after it has exited the media channels.

Abstract: A fuel cell arrangement with a membrane electrode assembly is provided which comprises a cathode, an anode and a membrane arranged between the cathode and the anode, with an active area essentially predetermined by the membrane electrode assembly, and with a sealing structure laterally assigned to the membrane electrode assembly. The sealing structure comprises a sealing tongue extending into or over an edge region outside the active area for axially covering in a gas-tight manner a media channel formed in an adjacent bipolar plate and located in the edge region. A unit cell for a fuel cell stack with such a fuel cell arrangement is also provided.

Abstract: A kit for a fuel cell stack comprises a first plurality of unit cells of the same design, which can be stacked on top of each other in a stacking direction and which each have one or more media channels and a membrane electrode assembly, the membrane electrode assembly comprising a cathode, an anode, and a membrane arranged between the cathode and the anode, a first media guide, which can be laterally connected to the first plurality of unit cells and runs parallel to the stacking direction, having a first usable flow cross section, in order to guide a medium into or out from the media channels of the unit cells of the first plurality of unit cells substantially laterally with respect to the stacking direction, a second plurality of unit cells of the same design, and a second media guide, which can be connected laterally to the two pluralities of unit cells stacked on top of one another and running parallel to the stacking direction, having a second usable flow cross section, different from the first usable f

Abstract: A fuel cell device comprises a fuel cell stack which is formed from a plurality of unit cells stacked one above the other in a stacking direction, each unit cell having one or more media channels and a membrane electrode assembly that comprises a cathode, an anode, and a membrane arranged between the cathode and the anode, and comprising a media duct running substantially parallel to the stacking direction. The media duct is connected or can be connected to the fuel cell stack to conduct a medium into or out of the media channels of the unit cells of the fuel cell stack substantially laterally to the stacking direction. The media duct is formed as a functional component or such a functional component is integrated therein, which is formed to pre-treat the medium before it enters the media channels or to post-treat the medium after it has exited the media channels.

Abstract: A fuel cell device is provided comprising a fuel cell stack which is formed from a plurality of unit cells stacked one above the other in a stacking direction, each unit cell having one or more media channels and a membrane electrode assembly that comprises a cathode, an anode and a membrane arranged between the cathode and the anode, and comprising a media duct running substantially parallel to the stacking direction. The media duct is connected or can be connected to the fuel cell stack to conduct a medium into or out of the media channels of the unit cells of the fuel cell stack substantially laterally to the stacking direction, and comprises duct flanges that are connected at least indirectly to each other and can be connected or are connected to the fuel cell stack. The duct flanges of the media duct are inserted into flange receptacles of the fuel cell stack running substantially parallel to the stacking direction.

Abstract: A fuel cell device is provided comprising a fuel cell stack, which is formed from a plurality of unit cells which are stacked one above the other in a stacking direction and which each have one or more media channels and a membrane electrode assembly, which comprises a cathode, an anode and a membrane arranged between the cathode and the anode, as well as comprising a media guide extending essentially in parallel to the stacking direction. The media guide can be or is connected to the fuel cell stack in such a way as to guide a medium essentially laterally to the stacking direction into or out of the media channels of the unit cells of the fuel cell stack.

Abstract: A fuel cell arrangement with a membrane electrode assembly is provided which comprises a cathode, an anode and a membrane arranged between the cathode and the anode, with an active area essentially predetermined by the membrane electrode assembly, and with a sealing structure laterally assigned to the membrane electrode assembly. The sealing structure comprises a sealing tongue extending into or over an edge region outside the active area for axially covering in a gas-tight manner a media channel formed in an adjacent bipolar plate and located in the edge region. A unit cell for a fuel cell stack with such a fuel cell arrangement is also provided.