Polymer electrolyte fuel cell, method for its production and method for its operation, and module comprising multiple such polymer electrolyte fuel cells

Abstract

The invention relates to a polymer electrolyte fuel cell wherein a first reaction compartment and a second reaction compartment are separated from one another by two polymer electrolyte membrane layers. In this cell, the first and second reaction compartments are rolled up adjacently to one another to form a hollow cylinder, with the second reaction compartment being open and the first reaction compartment being gas-imperviously closed at the outer faces of the hollow cylinder. The first reaction compartment here is closed by the ends of the two polymer electrolyte membrane layers, said ends being gas-imperviously joined to one another. Arranged in the interior of the hollow cylinder is an inner housing which has at least one opening. The first reaction compartment is gas-imperviously joined to the inner housing in such a way that a gas can enter the first reaction compartment from the inner housing through the at least one opening. The hollow cylinder is surrounded by an outer housing which has at least one opening. The first reaction compartment is gas-imperviously joined to the outer housing in such a way that a gas can exit the first reaction compartment through the at least one opening ...

Description

[0001] Polymer electrolyte fuel cell, method for its production and method for its operation, and module comprising several such polymer electrolyte fuel cells

[0002] The invention relates to a polymer electrolyte fuel cell, a method for its production and a method for its operation as well as a module comprising several such polymer electrolyte fuel cells.

[0003] A polymer electrolyte fuel cell generates electrical energy and heat by electrochemically reacting a fuel gas, such as hydrogen, with an oxidizing gas, such as oxygen.

[0004] A hydrogen ion-conducting membrane, also called a polymer electrolyte membrane, serves as the electrolyte and separates the two reaction chambers with their connected electrodes, i.e., the cathode and anode. Gas supply and electrical contact are usually established on the cathode and anode sides via bipolar plates with recesses for glass flow. In each reaction chamber, a fine-pored, electrically conductive structure, usually a gas diffusion layer made of a material with a fleece-like or paper-like structure, ensures gas transport to a catalyst layer, which is usually a carbon-based mixture with platinum group metals. The gas diffusion layer simultaneously conducts the resulting current from the catalyst layer to the respective electrode. The catalyst layer is in direct contact with the polymer electrolyte membrane or is directly deposited on it.A unit consisting of a polymer electrolyte membrane, cathode and anode catalyst material and gas diffusion layers is called a membrane-electrode-assembly (MEA) or single cell.

[0005] Membrane electrode units are connected to the bipolar plates arranged in between via adhesive bonds or seals to form a stack, also called a module. Similar reaction chambers, i.e. cathode or anode chambers, are connected to one another via gas flow passages formed as cutouts in the bipolar plates. Each bipolar plate acts as a current supply to the anode of a membrane electrode unit and to the cathode of an adjacent membrane electrode unit. The stacking thus corresponds to a series connection of individual cells, i.e. the voltages of the individual cells are added. At the beginning and end of the stack, mechanical cohesion is ensured by end plates and bracing, e.g. tension rods, which extend through the entire stack from one end of the stack to the other. Electrical contact is made via current collectors, e.g. metallic plates arranged at both ends of the stack.The end plates have holes that serve as gas inlets and outlets, as well as for the removal of products, usually water or steam. The end plates are usually made of an electrically insulating material or are electrically insulated from the individual cells by insulating plates.

[0006] Such a structure of a polymer electrolyte fuel cell or a polymer electrolyte fuel cell stack is described in DE 11 2008 000 024 B4.

[0007] The plate-like structure has several disadvantages: Firstly, it is necessary to generate a uniform force across the entire lateral extent of the individual cells, i.e., within a plane perpendicular to the stacking direction, in order to prevent leakage of the supplied or discharged gases and products and the failure of individual cells. Secondly, due to the series connection of the individual cells, the failure of a single cell can lead to the failure of the entire module. Furthermore, the dissipation of the heat generated during the chemical reaction presents a challenge, which is ensured, for example, with additional cooling water passages. Furthermore, the scalability of the individual cell and the module, as well as the power density, are limited.

[0008] In order to increase the power density or power-to-weight ratio, it was proposed in DE 10 2015 207 455 A1 to thin the electrode or bipolar plates, which, however, has a negative effect on the mechanical stability of a single cell.

[0009] The object is therefore to provide an alternative design of a polymer electrolyte fuel cell that mitigates the disadvantages of the prior art. Furthermore, the object is to provide a module comprising several alternative polymer electrolyte fuel cells, as well as a method for producing such an alternative polymer electrolyte fuel cell and a method for operating such an alternative polymer electrolyte fuel cell.

[0010] According to the invention, this object is achieved by a polymer electrolyte fuel cell, a module comprising several polymer electrolyte fuel cells, a method for producing a polymer electrolyte fuel cell, and a method for operating a polymer electrolyte fuel cell according to the independent claims. Advantageous embodiments of the invention are specified in the dependent claims.

[0011] A first aspect of the invention relates to a polymer electrolyte fuel cell comprising a first reaction chamber, e.g., an anode chamber, a second reaction chamber, e.g., a cathode chamber, and two hydrogen-ion-conducting polymer electrolyte membrane layers. The first reaction chamber contains two first gas diffusion layers and a first electrically conductive, three-dimensional lattice structure arranged between the first gas diffusion layers, as well as a first catalyst. The second reaction chamber contains two second gas diffusion layers and a second electrically conductive, three-dimensional lattice structure arranged between the second gas diffusion layers, as well as a second catalyst.

[0012] The first and second gas diffusion layers consist of an electrically conductive material with a structure that enables gas transport and, in particular, also a fine distribution of the gas passing through and the removal of the reaction product water. Such materials are known to those skilled in the art from the prior art, so that the following materials are listed here only as examples: carbon, polymers such as PTFE (polytetrafluoroethylene) or metals such as titanium or stainless steel or composite materials, e.g., made of two or more of the materials mentioned. The gas diffusion layers have a thickness in the range from 0.05 mm to 2 mm, preferably in the range from 0.1 mm to 0.5 mm, and particularly preferably in the range from 0.15 mm to 0.4 mm. The first and second gas diffusion layers can be of the same or different materials and thicknesses.For example, the first gas diffusion layers may be surface-treated to be hydrophobic, while the second gas diffusion layers may be surface-treated to be hydrophilic, or vice versa.

[0013] The first and second grid structures are made of any material with good electrical conductivity, i.e. a sheet resistance of less than 10 Ω, preferably with a sheet resistance of less than 1 mfi, and allow sufficient flow for the respective gas. The first and second grid structures can, for example, be a structure made of individual wires made of metal, electrically conductive carbon or other electrically conductive materials, wherein the wires are connected to one another three-dimensionally, e.g. woven or braided, welded, soldered or glued. A wire can have any cross-sectional shape. Fabrics made of polymer that have been made electrically conductive by a coating can also be used. The grid structures can also be designed in the form of electrically conductive spacers that are electrically connected to one another, or can be regarded as such.When selecting the material, attention must be paid to chemical resistance to the gases and products being supplied and removed. The first and second grid structures have a thickness in the range of 0.05 mm to 2 mm, preferably in the range of 0.1 mm to 1 mm, and particularly preferably in the range of 0.1 mm to 0.5 mm. The first and second grid structures can be of the same or different design with regard to their material, flow capacity, and thickness.

[0014] The first and second catalysts are formed in at least one of the following forms: as a layer on the corresponding first or second gas diffusion layer, as a layer on one of the polymer electrolyte membrane layers, or as a reactive component in the corresponding first or second gas diffusion layer. Platinum group metals, i.e., Ru, Rh, Pd, Os, Ir, and Pt, can be incorporated into the material of the gas diffusion layer as a component of the gas diffusion layer, at least in the regions adjacent to the polymer electrolyte membrane layer. Carbon-based mixtures with platinum group metals, or thin layers of a platinum group metal, can be used as the layer, with the layer being arranged adjacent to the polymer electrolyte membrane layer.This means that the first catalyst borders the polymer electrolyte membrane layers on the side of the polymer electrolyte membrane layers facing the first reaction chamber, while the second catalyst borders the polymer electrolyte membrane layers on the side of the polymer electrolyte membrane layers facing away from the first reaction chamber. For the purposes of this application, a platinum group metal is understood not only to mean the element as such, such as platinum or ruthenium, but also a mixture or alloy with at least one element of this group, e.g., platinum and ruthenium, platinum and nickel, or platinum and cobalt. If the first or second catalyst is formed as a layer on the respective gas diffusion layer or on one of the polymer electrolyte membrane layers, they have a loading density in the range of 0.05 mg / cm3 in the case of catalyst alloys containing precious metals. 2 up to 50 mg / cm 2 preferably in the range of 0.1 mg / cm2 up to 1 mg / cm 2 With noble metal-free catalyst materials, the loading density can be significantly higher. The first and second catalysts can be made of the same or different materials and can have the same or different shapes and thicknesses.

[0015] The first and second polymer electrolyte membrane layers consist of a hydrogen ion-conducting but gas-tight polymer, which is known in principle from the prior art. Examples are perfluorinated copolymers with sulfo groups. The first and second polymer electrolyte membrane layers have a thickness in the range of 0.01 mm to 0.5 mm, preferably in the range of 0.02 mm to 0.2 mm. Preferably, both polymer electrolyte membrane layers are made of the same material and have the same thickness. The first polymer electrolyte membrane layer is arranged on a first surface of the first reaction chamber, and the second polymer electrolyte membrane layer is arranged on a second surface of the first reaction chamber, with the second surface opposite the first surface. The two polymer electrolyte membrane layers are each connected to one another in a gas-tight manner at two opposite ends of the first reaction chamber.

[0016] All of the previously mentioned components of the polymer electrolyte fuel cell—i.e., the gas diffusion layers, the grid structures, the catalysts (when applied as a layer), and the polymer electrolyte membrane layers of the present invention—are characterized by high flexibility, which is influenced by the bending radius and thus by the size and shape of the fuel cell modules to be manufactured. The possible bending radius of the components and of the stacked components to form layers must be tested experimentally in bending tests or tests to roll up the structures, or by simulation. In particular, the materials, the adhesive, the weld or solder seam, and the design of the components must enable bending through their material properties. The achievable bending radius lies in the range between the radius of the inner housing and the radius of the outer housing, including both limit values.These properties are necessary to ensure the integrity, stability, and functionality of the individual components, and in particular the tightness of the first reaction chamber even when rolled up. An important feature of the polymer electrolyte fuel cell according to the invention is that the first and second reaction chambers are rolled up adjacent to one another to form a hollow cylinder. The first reaction chamber is separated from the second reaction chamber within the hollow cylinder by the first and second polymer electrolyte membrane layers. Furthermore, the second reaction chamber is open at the top surfaces of the hollow cylinder, while the gas-tight ends of the two polymer electrolyte membrane layers of the first reaction chamber are arranged at the top surfaces of the hollow cylinder.The hollow cylinder is thus formed by several superimposed layers of the first and second reaction chambers and the polymer electrolyte membrane layers arranged therebetween, with at least two layers of the first reaction chamber and two layers of the second reaction chamber being arranged next to one another along a radial direction of the hollow cylinder. Preferably, 5 to 500 layers of the first and 5 to 500 layers of the second reaction chamber are arranged next to one another along a radial direction of the hollow cylinder. The hollow cylinder has a height measured along the axis of the hollow cylinder. The hollow cylinder can have a round, oval, square, or any other desired closed outer circumferential shape, as well as a round, oval, square, or any other desired closed inner circumferential shape in cross-section. However, the inner and / or outer circumferential shape do not have to be ideal, e.g.They are not ideally round, but can each have transitions between the first and second reaction chambers or between individual components of the first and second reaction chambers, e.g., between one of the first gas diffusion layers and the first lattice structure, or between the first or second reaction chamber and the first or second polymer electrolyte membrane layer. Furthermore, the inner and outer peripheral shapes can differ from one another. In embodiments, the inner and outer peripheral shapes are approximately round.

[0017] The polymer electrolyte fuel cell according to the invention further comprises an inner housing and an outer housing. The inner housing is arranged inside the hollow cylinder and has at least one opening, wherein the first reaction chamber is connected to the inner housing in a gas-tight manner such that a gas from the inner housing can enter the first reaction chamber through the at least one opening of the inner housing. The outer housing surrounds the hollow cylinder and has at least one opening, wherein the first reaction chamber is connected to the outer housing in a gas-tight manner such that a gas can escape from the first reaction chamber through the at least one opening of the outer housing.The gas-tight connection of the first reaction chamber to the inner and / or outer housing is preferably achieved by means of the first and second polymer electrolyte membrane layers, which are connected in a gas-tight manner to the inner housing and the outer housing separately over the entire height of the hollow cylinder and each enclose the at least one opening. In other words: the first reaction chamber is separated in a gas-tight manner on all sides from the second reaction chamber or from other adjacent environments, namely on the cover surfaces and within the hollow cylinder by the first and second polymer electrolyte membrane layers, which are connected to one another in a gas-tight manner at the cover surfaces of the hollow cylinder, as well as to the inner housing and the outer housing, preferably likewise by means of a gas-tight connection of the first and second polymer electrolyte membrane layers to the respective housing.

[0018] Thus, a hydrogen-containing fuel gas, e.g., H2, can be introduced into the first reaction chamber, and unreacted fuel gas can be removed from the first reaction chamber without coming into direct contact with an oxygen-containing oxidizing gas, e.g., O2, introduced into the second reaction chamber, or with an oxygen-containing ambient atmosphere. This increases the safety of such a fuel cell. Furthermore, the rolled-up arrangement of the first and second reaction chambers achieves a high power density per unit weight and high mechanical stability of the fuel cell. The second lattice structure, due to its permeability and the large surface area of ​​the second reaction chamber, enables effective dissipation of the reaction heat generated in the fuel cell. At the same time, the dimensions of the first and second reaction chambers, iealong the axis of the hollow cylinder and along the winding from the inside to the outside, as well as via the number of windings, various possibilities for adjusting the electrical parameters of the polymer electrolyte fuel cell according to the invention, in particular the generated current, so that the fuel cell is easily scalable. In embodiments, the hollow cylinder has an inner width, e.g. an inner diameter, in the range from 3 mm to 250 mm, preferably from 5 mm to 50 mm, and an outer width, e.g. an outer diameter, in the range from 10 mm to 1000 mm, preferably from 30 mm to 200 mm, wherein the inner and outer widths are measured in a radial plane of the hollow cylinder. In further embodiments, the hollow cylinder has a height measured along the axis of the hollow cylinder in the range from 10 mm to several meters (<10 m), preferably from 50 mm to 2000 mm.

[0019] The inner housing serves to supply a gas into the first reaction chamber, for which purpose it has at least one opening, wherein the inner housing is connected to the first reaction chamber in a gas-tight manner such that the gas from the inner housing can only enter the first reaction chamber through the at least one opening. The inner housing can be designed in any desired manner with regard to its shape and material, as long as functionality is ensured, i.e. a gas-tight connection to the first reaction chamber and chemical compatibility with the supplied gas. The inner housing can, for example, be in the form of a flexible hose made of metal, plastic or a composite material with a round, oval or square cross-section. Electrical contacting or electrical insulation of the inner housing can be enabled or avoided by surface treatment or coating.

[0020] In embodiments, the inner housing is a tube, e.g. made of metal, plastic, ceramic, or a composite material, where a tube is understood to be a rigid hollow body with any cross-section. In embodiments, the tube has a round cross-section whose outer diameter corresponds to or is smaller than the smallest inner width of the hollow cylinder. If the hollow cylinder has a nearly round inner circumferential shape, the outer diameter of the tube is equal to or only slightly smaller than the inner diameter (inner width) of the hollow cylinder. The tube further improves the mechanical stability of the polymer electrolyte fuel cell. The at least one opening of the inner housing can, for example, be a slot or an elongated hole that extends over at least part of the height of the hollow cylinder, but not beyond the hollow cylinder.The height of the hollow cylinder is the dimension of the hollow cylinder measured along the axis of the hollow cylinder. The width of the at least one opening in the inner housing is dimensioned such that a gas-tight connection to the first reaction chamber can be created. Preferably, the width of the at least one opening is equal to or smaller than the width of the first reaction chamber at the interface to the inner housing, wherein the widths, i.e. the width of the at least one opening and the width of the first reaction chamber at the interface to the inner housing, are each measured along the outer circumferential line of the inner housing in a cross-section perpendicular to the axis of the hollow cylinder. The inner housing can also have a plurality of openings, all of which are, however, connected to the first reaction chamber in a gas-tight manner. A plurality of openings can, for example, be arranged next to one another along a direction that runs parallel to the axis of the hollow cylinder.

[0021] In embodiments, the inner housing has a means for closing the at least one opening, so that the supply of a gas into the first reaction chamber can be interrupted or prevented. Such a means can be, for example, a valve that can prevent the passage of gas from the inner housing into the at least one opening or the supply of gas to the inner housing.

[0022] In embodiments, the inner housing is electrically conductive in at least one region, and the at least one electrically conductive region is electrically conductively connected to at least the first or second grid structure of the first or second reaction chamber. Thus, if the at least one electrically conductive region of the inner housing is connected to an electrode, current can be discharged from the first or second reaction chamber via this region. In particular embodiments, two mutually different regions of the inner housing are electrically conductive, wherein the two regions are electrically insulated from one another, one of the regions being electrically conductively connected to the first grid structure of the first reaction chamber, and the other of the regions being electrically conductively connected to the second grid structure of the second reaction chamber.Of course, one of the first or second grid structures can also be electrically contacted in another way. For example, the second grid structure of the second reaction chamber, which is open at the cover surfaces of the hollow cylinder, can be contacted at one of the cover surfaces of the hollow cylinder. Furthermore, it is also possible to electrically contact one of the first or second grid structures or both via the outer housing, as described below. The outer housing serves to discharge a gas from the first reaction chamber, for which purpose it has the at least one opening, wherein the outer housing is connected to the first reaction chamber in a gas-tight manner, such that the gas from the first reaction chamber can only enter the outer housing through the at least one opening. The outer housing can be designed as desired with regard to its shape and material, as long as functionality is ensured, i.e.the gas-tight connection to the first reaction chamber and chemical compatibility with the discharged gas. The outer housing can be designed, for example, in the form of a flexible hose or a box made of metal, plastic, ceramic, glass, or a composite material with a round, oval, or square cross-section. Preferably, the outer housing is designed as a hollow body having an empty interior space between an inner wall and an outer wall, wherein the inner wall adjoins the outer surface of the hollow cylinder. Thus, the gas discharged from the first reaction chamber is collected inside the outer housing and separated from the environment.

[0023] In embodiments, the outer casing is a double-walled tube, e.g., made of metal, plastic, ceramic, or glass. A double-walled tube is understood to be a rigid hollow body with any cross-section that has an empty interior space between an inner wall and an outer wall. In embodiments, the tube has a round cross-section whose inner diameter corresponds to or is larger than the largest outer width of the hollow cylinder. If the hollow cylinder has a nearly round outer circumferential shape, the inner diameter of the tube is equal to or only slightly larger than the outer diameter (outer width) of the hollow cylinder. The tube further improves the mechanical stability of the polymer electrolyte fuel cell.

[0024] The at least one opening in the outer housing can, for example, be a slot or an elongated hole which extends over at least part of the height of the hollow cylinder, but not beyond the hollow cylinder. The width of the at least one opening in the outer housing is dimensioned such that a gas-tight connection to the first reaction chamber can be created. Preferably, the width of the at least one opening is equal to or smaller than the width of the first reaction chamber at the interface to the outer housing, wherein the widths, i.e. the width of the at least one opening and the width of the first reaction chamber at the interface to the outer housing, are each measured along the inner circumferential line of the outer housing in a cross-section perpendicular to the axis of the hollow cylinder. The outer housing can also have a plurality of openings, which, however, are all connected to the first reaction chamber in a gas-tight manner. A plurality of openings can, for example,be arranged side by side along a direction parallel to the axis of the hollow cylinder.

[0025] In embodiments, the outer housing has a means for closing the at least one opening, so that the discharge of a gas from the first reaction chamber can be interrupted or prevented. Such a means can, for example, be a valve that can prevent the passage of gas into the outer housing through the at least one opening.

[0026] Although it has been described here that the inner housing serves to supply a gas into the first reaction chamber and the outer housing serves to discharge a gas from the first reaction chamber, these functions can of course also be reversed. That is, the outer housing can serve to supply a gas into the first reaction chamber, while the inner housing serves to discharge a gas from the first reaction chamber.

[0027] In embodiments, the outer housing is designed to be electrically conductive in at least one region, and the at least one electrically conductive region is electrically conductively connected to at least the first or second grid structure of the first or second reaction chamber. Thus, if the at least one electrically conductive region of the outer housing is connected to an electrode, current can be discharged from the first or second reaction chamber via this region. In particular embodiments, two different regions of the outer housing are designed to be electrically conductive, the two regions being electrically insulated from one another, one of the regions being electrically conductively connected to the first grid structure of the first reaction chamber, and the other of the regions being electrically conductively connected to the second grid structure of the second reaction chamber.Of course, one of the first or second grid structures can also be electrically contacted in a different way, as described above with reference to the inner housing. For example, one of the first or second reaction chambers or their grid structures can be electrically contacted via the inner housing, and the other of the first or second reaction chambers or their grid structures can be electrically contacted via the outer housing.

[0028] As already mentioned, an important feature of the polymer electrolyte fuel cell according to the invention is that the first and second polymer electrolyte membrane layers are each connected to one another in a gas-tight manner at two opposite ends of the first reaction chamber. In embodiments, the polymer electrolyte membrane layers are bonded to one another in a gas-tight manner, e.g., using a silicone- or polyurethane-based adhesive or adhesive strip. In other embodiments, the polymer electrolyte membrane layers are welded to one another in a gas-tight manner, i.e., the two polymer electrolyte membrane layers form a material bond under elevated temperature and / or elevated pressure.If the gas-tight connection of the first reaction chamber to the inner and / or outer housing is achieved by means of the first and second polymer electrolyte membrane layers, in embodiments the first and second polymer electrolyte membrane layers are each glued or welded to the inner housing and / or the outer housing, wherein different connection forms can be used for different connection points.

[0029] A further aspect of the invention relates to a module comprising several polymer electrolyte fuel cells according to the invention, wherein at least two of the polymer electrolyte fuel cells are connected in series or in parallel. In a series connection, the generated electrical voltage of the module can be adjusted by the number of fuel cells connected in series, whereas in a parallel connection, the generated electrical current of the module can be adjusted by the number of fuel cells connected in parallel. In both cases, the generated electrical power of the module can be adapted to the needs of a user.

[0030] In embodiments of the module according to the invention, at least two of the polymer electrolyte fuel cells have a common inner housing and are arranged one behind the other along the direction along which the inner housing extends. In further embodiments, alternatively or additionally, at least two of the polymer electrolyte fuel cells have a common outer housing and are arranged one behind the other along the direction along which the outer housing extends.For example, several hollow cylinders can be arranged one below the other or next to the other on a common inner tube, which forms the inner housing and has at least one opening in each region of one of the hollow cylinders, which is connected in a gas-tight manner to the first reaction space of the respective hollow cylinder, and can be surrounded by a common outer double-walled tube, which forms the outer housing and has at least one opening in each region of one of the hollow cylinders, which is connected in a gas-tight manner to the first reaction space of the respective hollow cylinder. Preferably, the common inner housing has means for each of the hollow cylinders for closing the openings, which are connected to the first lattice structures of the respective hollow cylinder. This allows one or more fuel cells, which are damaged due to a defect within the hollow cylinder, e.g.due to a leak between the first and second reaction chambers of the hollow cylinder in question, cannot be used, can be separated from a gas supply and essentially removed from the module without actually having to physically remove them. This of course provides that the electrical interconnection of the other fuel cells in the module is still guaranteed. If several fuel cells in the module have a common outer housing, this housing similarly has means for closing the openings that are connected to the first lattice structures of an individual hollow cylinder. If, in addition to one of the aforementioned embodiments with a common inner and / or a common outer housing, regions of the inner housing and / or the outer housing are also designed to be electrically conductive and are electrically conductively connected to at least the first lattice structure or the second lattice structure of the first reaction chamber orof the second reaction chamber of a respective hollow cylinder, the serial or parallel electrical connection of the individual fuel cells can be realized via the inner and / or outer housing, whereby a parallel connection is particularly easy to realize.

[0031] A further aspect of the invention relates to a method for producing a polymer electrolyte fuel cell according to the invention, wherein the method comprises the following steps: producing a flat precursor, rolling the flat precursor to form a hollow cylinder, providing an inner housing and gas-tightly connecting the first reaction chamber to the inner housing, and providing an outer housing and gas-tightly connecting the first reaction chamber to the outer housing. The step of producing a flat precursor includes the following substeps:

[0032] • Providing two first gas diffusion layers,

[0033] • Providing a first polymer electrolyte membrane layer and a second polymer electrolyte membrane layer,

[0034] • Applying a first catalyst to the first and second

[0035] Polymer electrolyte membrane layer and / or on the first gas diffusion layers, if the first catalyst is not already contained in the first gas diffusion layers,

[0036] • Providing two second gas diffusion layers,

[0037] • Applying a second catalyst to the first and second

[0038] Polymer electrolyte membrane layer on one side of the first and second

[0039] Polymer electrolyte membrane layer on which the first catalyst is not applied, and / or on the second gas diffusion layers if the second catalyst is not already contained in the second gas diffusion layers,

[0040] • Forming a first reaction space by arranging the first gas diffusion layers, the first and second polymer electrolyte membrane layers and a first electrically conductive and three-dimensional lattice structure one above the other such that the first lattice structure is arranged between the two first gas diffusion layers and one of the two first gas diffusion layers borders the first polymer electrolyte membrane layer or the first catalyst on the first polymer electrolyte membrane layer and the other of the two first gas diffusion layers borders the second polymer electrolyte membrane layer or the first catalyst on the second polymer electrolyte membrane layer,

[0041] • Gas-tight connection of the first and second polymer electrolyte membrane layers at two opposite ends of the first reaction chamber,

[0042] • Connecting one of the two second gas diffusion layers to the first polymer electrolyte membrane layer or to the second catalyst applied to the first polymer electrolyte membrane layer such that the second gas diffusion layer is arranged on the side of the first polymer electrolyte membrane layer facing away from the first reaction space, wherein the connection takes place before or after the formation of the first reaction space,

[0043] • connecting the other second gas diffusion layer to the second polymer electrolyte membrane layer or to the second catalyst applied to the second polymer electrolyte membrane layer such that the second gas diffusion layer is arranged on the side of the second polymer electrolyte membrane layer facing away from the first reaction space, wherein the connection takes place before or after the formation of the first reaction space, and

[0044] • Applying a second electrically conductive and three-dimensional lattice structure to the other second gas diffusion layer.

[0045] Some of the sub-steps can be carried out in any order or even simultaneously. For example, the first and second gas diffusion layers can be provided at the same time and provided with the first or second catalyst at the same time, in the same or in different treatment plants. If the first and / or second catalyst is not applied to the first or second gas diffusion layers, but rather to the first and / or second polymer electrolyte membrane layer, this can also be done simultaneously. If the same catalyst material is used for the first and second catalyst, this process can also be done in the same treatment plant. The sub-steps for connecting the two second gas diffusion layers to the first or second gas diffusion layers can also be carried outThe second polymer electrolyte membrane layer can be applied before or after forming the first reaction space and before or after the gas-tight bonding of the first and second polymer electrolyte membrane layers. Even the application of the second lattice structure to the other second gas diffusion layer can be performed at any time, provided that the application of the second catalyst to the second gas diffusion layer and / or the bonding of the other second gas diffusion layer to the second polymer electrolyte membrane layer can still be performed thereafter.

[0046] Preferably, however, partial precursors are produced, which are then superimposed in the order in which they will later be present and, if necessary, bonded together. Such partial precursors can be, for example, the first and second gas diffusion layers or the first and second polymer electrolyte membrane layers, to each of which the first and / or second catalyst is applied. It is also possible to purchase partial precursors, so that the step of applying the first and / or second catalyst can also be omitted.

[0047] Thus, in one embodiment of the method, for example, the process begins with the provision of the first gas diffusion layers and the second gas diffusion layers, which already contain the first and second catalysts, respectively, or with the provision of the first gas diffusion layers and the second gas diffusion layers and the application of the first and second catalysts to the first and second gas diffusion layers, respectively. The actual construction of the sheet-like precursor begins with the arrangement of the first polymer electrolyte membrane layer on one of the second gas diffusion layers. One of the first gas diffusion layers is arranged on the first polymer electrolyte membrane layer, above it the first lattice structure, on top of this the other of the first gas diffusion layers, and above it the second polymer electrolyte membrane layer, thereby forming the first reaction chamber.Then, the other of the second gas diffusion layers is arranged on the second polymer electrolyte membrane layer, followed by the second grid structure. The first and second polymer electrolyte membrane layers are then joined together in a gas-tight manner at the opposite ends of the first reaction chamber. However, it is also possible to start with the first polymer electrolyte membrane layer, on which one of the first gas diffusion layers is arranged, followed by the first grid structure, the other of the first gas diffusion layers, and the second polymer electrolyte membrane layer. The first reaction chamber thus formed can then, or later, be sealed at opposite ends by joining the first and second polymer electrolyte membrane layers together in a gas-tight manner.Subsequently, one of the second gas diffusion layers, the second grid structure, and the other of the second gas diffusion layers are arranged on the first or second polymer electrolyte membrane layer on the side facing away from the first reaction chamber. Or, one of the second gas diffusion layers is arranged on the side of the first polymer electrolyte membrane layer facing away from the first reaction chamber, and the other of the second gas diffusion layers and the second grid structure are arranged on the side of the second polymer electrolyte membrane layer facing away from the first reaction chamber. It is thus apparent to those skilled in the art that there are various embodiments of the method with different sequences and, if appropriate, combinations of the aforementioned substeps that can be carried out.

[0048] The first or second catalyst can be applied by vapor deposition, e.g., by vapor deposition, sublimation, sputtering, chemical vapor deposition with or without plasma, or by liquid deposition, e.g., by spin coating, rolling, or dipping into a bath, or by solid deposition, e.g., as particles dissolved in a suspension or as a paste by doctor blade coating. This may include preparatory cleaning steps, drying or heat treatment steps, or subsequent cleaning steps. These methods are known to those skilled in the art.

[0049] For the purposes of this application, the placement of a specific layer on top of another layer is understood to mean any technique that results in the abutment of these two layers. In particular, examples of such a technique include placing one layer on top of another or rolling one layer onto the other.

[0050] The production of a flat precursor according to the method according to the invention enables the use of flat starting materials that can be obtained from other producers, such as gas diffusion layers, polymer electrolyte membrane layers, or even lattice structures. Furthermore, the starting materials can initially be processed in large dimensions and then cut to the appropriate size of the fuel cell to be produced before the two polymer electrolyte membrane layers are gas-tightly bonded at the opposite ends of the first reaction chamber. This enables simple, cost-effective processing of the starting materials and the use of a linear inline process.

[0051] After the flat precursor has been produced, it is rolled up to form a hollow cylinder. The rolling process positions the individual layers of the flat precursor relative to one another such that the second catalyst, the second gas diffusion layers, and the second electrically conductive and three-dimensional lattice structure form a second reaction chamber that is open at the top surfaces of the hollow cylinder and, within the hollow cylinder, is separated from the first reaction chamber by the first and second polymer electrolyte membrane layers. The flat precursor is rolled up such that the gas-tight ends of the first and second polymer electrolyte membrane layers are each arranged on the top surfaces of the hollow cylinder.A further step of the method according to the invention for producing the polymer electrolyte fuel cell according to the invention includes providing an inner housing having at least one opening and gas-tightly connecting the first reaction chamber to the inner housing such that a gas can enter the first reaction chamber from the inner housing through the at least one opening of the inner housing or exit the first reaction chamber through the at least one opening of the inner housing into the inner housing. The gas-tight connection of the first reaction chamber to the inner housing can take place before, during, or after the rolling of the flat precursor.

[0052] Preferably, the sheet-like precursor is rolled directly onto or around the inner housing. The gas-tight connection preferably occurs before or during the rolling of the sheet-like precursor; however, it can also occur afterward. The inner housing can also be inserted into the hollow cylinder after its creation by rolling the sheet-like precursor and connected in a gas-tight manner to the first reaction chamber. Thus, parts of the step of providing the inner housing and of connecting it to the first reaction chamber in a gas-tight manner can also be carried out separately from one another before, during, or after other steps of the method according to the invention for producing a polymer electrolyte fuel cell according to the invention.

[0053] A further step of the method according to the invention for producing a polymer electrolyte fuel cell according to the invention includes providing an outer housing having at least one opening, and gas-tightly connecting the first reaction chamber to the outer housing such that a gas can escape from the first reaction chamber through the at least one opening in the outer housing into the outer housing or can enter the first reaction chamber (10) from the outer housing (7) through the at least one opening (74) in the outer housing (7). The gas-tight connection takes place after the flat precursor has been rolled up, i.e. after the hollow cylinder has been produced.

[0054] In embodiments of the method, the polymer electrolyte membrane layers are glued to one another in a gas-tight manner. The gas-tight connection of the first reaction chamber to the inner housing and / or to the outer housing can also be achieved by gas-tight bonding of the polymer electrolyte membrane layers to the inner or outer housing. For bonding, an adhesive, e.g. a silicone- or polyurethane-based adhesive or adhesive strip, is applied to at least one of the components to be connected, e.g. the first and second polymer electrolyte membrane layers or the first or second polymer electrolyte membrane layers and the inner or outer housing. The components to be connected are arranged adjacent to one another, and the adhesive bond is then fixed, e.g. by curing the adhesive. The curing of the adhesive can occur, for example, by an elevated temperature or irradiation with light, e.g. UV light.Bonding methods are known to those skilled in the art. The adhesive can also be applied to the starting products, i.e., the prepared polymer electrolyte membrane layers and / or the inner or outer housing, in the areas to be bonded later.

[0055] In other embodiments of the method, the polymer electrolyte membrane layers are welded together in a gas-tight manner. The gas-tight connection of the first reaction chamber to the inner housing and / or to the outer housing can also be achieved by gas-tight welding of the polymer electrolyte membrane layers to the inner or outer housing, if the material of the inner or outer housing allows this. During welding, the components to be connected, for example the first and second polymer electrolyte membrane layers or the first or second polymer electrolyte membrane layers and the inner or outer housing, are exposed to an elevated temperature and / or elevated pressure while arranged adjacent to one another, thus creating a material-to-material connection between the components to be connected. Welding methods are known to those skilled in the art.

[0056] Different connection forms can be used for different connection points of the first or second polymer electrolyte membrane layer with the inner housing or the outer housing. However, in embodiments, all gas-tight connections between the first and second polymer electrolyte membrane layers with each other or with the inner and outer housing are implemented in the same way.

[0057] A module according to the invention comprising a plurality of polymer electrolyte fuel cells according to the invention is achieved by carrying out the method described above for a plurality of fuel cells and electrically connecting the plurality of fuel cells in series or parallel. Some of the steps for producing the individual fuel cells can also be carried out jointly. For example, a plurality of flat precursors can be rolled simultaneously onto a common inner housing, and the respective first reaction chambers can be connected to it in a gas-tight manner. The provision of the outer housing and its gas-tight connection to the respective first reaction chambers can also be carried out simultaneously for a plurality of fuel cells if a common outer housing is used.

[0058] A further aspect of the invention relates to a method for operating a polymer electrolyte fuel cell according to the invention. A hydrogen-containing fuel gas is introduced into the first reaction chamber via the inner housing, and an oxygen-containing oxidation gas is introduced into the second reaction chamber. Current is discharged via a first electrode and a second electrode. The first electrode is electrically conductively connected to the first electrically conductive, three-dimensional grid structure, and the second electrode is electrically conductively connected to the second electrically conductive, three-dimensional grid structure. For example, H2 with appropriate purity, e.g., 99.999% H2, can be used as the hydrogen-containing reaction gas. For example, O2 or normal air can be used as the oxygen-containing oxidation gas.

[0059] In embodiments, the inner housing is electrically conductive in at least one region, and the at least one electrically conductive region is electrically conductively connected to at least the first or second grid structure of the first or second reaction chamber. In this case, the inner housing or at least the electrically conductive region of the inner housing serves as the first electrode and / or second electrode.

[0060] In embodiments, the outer housing is electrically conductive in at least one region, and the at least one electrically conductive region is electrically conductively connected to at least the first or second grid structure of the first or second reaction chamber. In this case, the outer housing or at least the electrically conductive region of the outer housing serves as the first electrode and / or second electrode.

[0061] In some embodiments, the outer housing serves to remove unreacted fuel gas from the first reaction chamber. This fuel gas is removed from the first reaction chamber via the at least one opening in the outer housing and can, for example, be collected in the outer housing and returned to the first reaction chamber via the inner housing.

[0062] Of course, the functions of the inner and outer housings can also be interchanged, so that a fuel gas is supplied to the first reaction chamber via the outer housing and unreacted fuel gas is removed from the first reaction chamber via the inner housing.

[0063] In further embodiments, the outer housing serves to discharge the resulting products, such as water. Of course, the resulting products can also be discharged via a further housing which is arranged between the inner and the outer housing. Furthermore, it is also possible for the space formed by an outer wall of the inner housing and the inner wall of the outer housing and which is not filled by the hollow cylinder to be regarded as part of the outer housing. In embodiments, the inner housing has a means for closing the at least one opening and the method for operating the fuel cell according to the invention has a step for closing the at least one opening of the inner housing with the aid of the closing means if a malfunction of the fuel cell occurs, e.g. a leak between the first and the second reaction chamber.

[0064] A method for operating a module comprising a plurality of the polymer electrolyte fuel cells according to the invention has, in principle, the same features as the method for operating an individual polymer electrolyte fuel cell according to the invention, wherein the closing of at least one opening of the inner housing of an individual fuel cell in the event of a malfunction of this individual fuel cell is of particular importance.

[0065] The polymer electrolyte fuel cell according to the invention can also be operated in reverse as an electrolyzer, wherein a hydrogen- and oxygen-containing medium, e.g., water (H2O), is supplied to the second reaction chamber, and an electrical voltage is applied between the first and second lattice structures, or an electrical current is supplied to the first and second lattice structures. In this case, oxygen and hydrogen ions or hydrogen protons are produced in the second reaction chamber, with the hydrogen ions passing through the first and second polymer electrolyte membrane layers into the first reaction chamber and reacting there to form hydrogen (H2). The hydrogen produced is discharged through the at least one opening in the inner housing and the at least one opening in the outer housing.

[0066] The invention is not limited to the embodiments illustrated and described, but also encompasses all embodiments having the same effect within the meaning of the invention. Furthermore, the invention is not limited to the specifically described combinations of features, but can also be defined by any other combination of specific features of all the individual features disclosed as a whole, provided that the individual features are not mutually exclusive or a specific combination of individual features is not explicitly excluded.

[0067] Examples of implementation

[0068] The invention will be explained in more detail below using several exemplary embodiments. The exemplary embodiments relate to a polymer electrolyte fuel cell according to the invention, a module comprising several such polymer electrolyte fuel cells, a method for producing a polymer electrolyte fuel cell according to the invention, and a method for operating such a polymer electrolyte fuel cell, and are intended to describe the invention without limiting it.

[0069] The invention is explained in more detail with the aid of drawings.

[0070] Fig. 1A is a schematic representation of the components of the first and second reaction chambers of an embodiment of the polymer electrolyte fuel cell according to the invention,

[0071] Fig. 1B is another view of the components shown in Fig. 1A,

[0072] Fig. 2 is a schematic representation of an inner housing and a hollow cylinder, consisting of the components shown in Fig. 1, an embodiment of the polymer electrolyte fuel cell according to the invention as well as the gas and product flows during operation of such a polymer electrolyte fuel cell,

[0073] Fig. 3 is a schematic plan view of an embodiment of the inventive

[0074] Polymer electrolyte fuel cell, with the outer casing also shown,

[0075] Fig. 4 is a schematic cross-section through the embodiment of Fig. 3,

[0076] Fig. 5A is a side view of the inner housing with an opening,

[0077] Fig. 5B is a side view of the inner wall of the outer housing with a

[0078] Opening,

[0079] Fig. 6A is a schematic cross-section through a module of three polymer electrolyte fuel cells according to the invention, which have a common inner and outer housing,

[0080] Fig. 6B the electrical diagram of this module,

[0081] Fig. 7A is a schematic flow chart of an embodiment of the method according to the invention for producing the polymer electrolyte fuel cell according to the invention,

[0082] Fig. 7B is a schematic flow chart of the first step of the embodiment shown in Fig. 7A and

[0083] Fig. 8A to 8D show various steps of the process according to Fig. 7A using cross sections through the respective product stage.

[0084] Figure 1A schematically shows components of a first reaction chamber 10 and a second reaction chamber 20 of an embodiment of the polymer electrolyte fuel cell according to the invention. The first and second reaction chambers 10, 20 are shown here as flat structures, each extending flatly along an xy-plane of a Cartesian xyz coordinate system and having a thickness and layering along the z-axis, and thus in a precursor stage of the polymer electrolyte fuel cell according to the invention. The first reaction chamber 10 is formed by two first gas diffusion layers 11a, 11b, a first catalyst 12, and a first lattice structure 13. The first lattice structure 13 is arranged between the two first gas diffusion layers 11a, 11b.Although the first catalyst 12 is applied to a surface of the first gas diffusion layers 11a and 11b facing away from the first lattice structure 13, it is not shown separately here for the sake of clarity. In other embodiments, the first catalyst can also be contained in the first gas diffusion layers. The second reaction chamber 20 is formed by two second gas diffusion layers 21a, 21b, a second catalyst 22, and a second lattice structure 23. Although the second catalyst 22 is also applied to a surface of the second gas diffusion layers 21a and 21b facing away from the second lattice structure 23, it is not shown separately here for the sake of clarity. In other embodiments, however, it can also be contained in the second gas diffusion layers, similar to the first catalyst. The second reaction chamber 20 is only formed by rolling up the second lattice structure 23 shown in Fig.1 is formed around the y-axis in its functional form, with the second lattice structure 23 then being arranged between the two second gas diffusion layers 21a and 21b. A polymer electrolyte membrane layer 30a and 30b, respectively, is arranged between a first gas diffusion layer 11a, 11b and a second gas diffusion layer 21a, 21b adjacent thereto. The two polymer electrolyte membrane layers 30a and 30b are connected to one another in a gas-tight manner at two opposite ends of the first reaction chamber 10. In the illustrated embodiment, they are glued together using an adhesive 31. In Fig. 1, only one end of the first reaction chamber 10 closed in this way is shown; the other end is located at a different position along the y-axis.

[0085] Figure 1B shows the same components as in Figure 1A, but this time more schematically, with the thicknesses of the individual components indicated. The first gas diffusion layers 11a and 11b have a thickness du in the range of 0.05 mm to 2 mm. The first catalyst 12 has a layer thickness di2 in the range of a few nanometers, corresponding to a loading density in the range of 0.05 mg / cm 2 up to 50 mg / cm 2for catalyst materials containing precious metals and a layer thickness di2 of up to 50 pm in the case of precious metal-free or mixed catalyst materials. The layers of the catalyst 12 are shown as a closed layer in Fig. 1 B, but this does not have to be the case. The first lattice structure 13 has a thickness di3 in the range from 0.05 mm to 2 mm. The second gas diffusion layers 21 a and 21 b, the second catalyst 22 and the second lattice structure 23 each have similar thicknesses d2i , d22 and d23 as the corresponding first components 11 a, 11 b, 12 and 13. The two polymer electrolyte membrane layers 30 a and 30 b each have a thickness d 30in the range of 0.02 mm to 0.2 mm. It should be noted again that Fig. 1B shows only a part of the extension of the components along the x-direction and that a gas-tight connection of the polymer electrolyte membrane layers 30a and 30b by an adhesive 31 is also present at the other end of the structure along the x-axis, which is not shown here.

[0086] Figure 2 shows a schematic representation of an inner housing 6 and a hollow cylinder 2, which consists of the components shown in Fig. 1, of an embodiment of the polymer electrolyte fuel cell according to the invention, as well as the gas and product flows during operation of such a polymer electrolyte fuel cell. An outer housing, which also belongs to the polymer electrolyte fuel cell according to the invention, is not shown in Fig. 2 for the sake of clarity and will be explained later with reference to Fig. 3. The hollow cylinder 2 was created by rolling up the first reaction chamber 10, the second reaction chamber 20, and the polymer electrolyte membrane layers 30a and 30b arranged therebetween. The glued ends of the two polymer electrolyte membrane layers 30a and 30b are present on the cover surfaces of the hollow cylinder 2.This means that the first reaction chamber is closed off from the environment at the top surfaces of the hollow cylinder 2, so that, for example, only the adhesive 31 is visible, while the second reaction chamber 20 is open at the top surfaces of the hollow cylinder 2. Thus, an oxygen-containing oxidation gas, e.g., O2 or air, can be fed into the second reaction chamber 20 at one top surface of the hollow cylinder 2, and unused oxidation gas, e.g., air, and reaction products, e.g., water (H2O), can be removed from the second reaction chamber 20 at another top surface of the hollow cylinder 2. A hydrogen-containing fuel gas, e.g., H2, is fed into the first reaction chamber 10 via the inner housing 6, which is a pipe in Fig. 2.For this purpose, the inner housing 6 has an opening which extends along the axis of the hollow cylinder 2 and within the hollow cylinder 2 and which is connected to the first reaction chamber 10 in such a way that the fuel gas can enter the first reaction chamber 10, but no fuel gas can escape from the first reaction chamber 10 or get into other components of the hollow cylinder 2 or into the environment. In other words: the first reaction chamber 10 is connected in a gas-tight manner to the opening of the inner housing 6 on the inner surface of the hollow cylinder 2 in that the polymer electrolyte membrane layers 30a and 30b enclose the opening of the inner housing 6 and are connected in a gas-tight manner to the inner housing 6. As shown in Fig. 2, unreacted fuel gas, e.g. H2, can be discharged from the first reaction chamber 10 to the outside, i.e. into an outer housing.Figure 3 shows a schematic plan view of an embodiment 1 of the polymer electrolyte fuel cell according to the invention, wherein, in addition to the components already explained in Fig. 2, an outer housing 7 is shown, which in the present case is also a tube. Fig. 3 shows a plan view of a cover surface 3 of the hollow cylinder 2. On the cover surface 3, as already described with reference to Fig. 2, the polymer electrolyte membrane layers bonded with the adhesive 31, which seal the first reaction chamber 10 in a gas-tight manner from the cover surfaces of the hollow cylinder, and the open second reaction chamber 20 are present. The hollow cylinder 2 has an inner width D. 2i and an outer width D 2a Inside the hollow cylinder 2 is the inner housing 6, which has an outer diameter which in this case is smaller than the inner width D 2iof the hollow cylinder 2, and is connected to the first reaction chamber 10 as described above. The outer housing 7 is designed as a double-walled tube having an opening on its inner surface which is connected in a gas-tight manner to the first reaction chamber 10 by the polymer electrolyte membrane layers enclosing the opening of the outer housing 7 and being connected in a gas-tight manner to the inner surface of the outer housing 7. The outer housing has an inner diameter, which is measured between opposite inner surfaces of the outer housing 7 and which, in the illustrated case, is greater than the outer width D 2a of the hollow cylinder 2.

[0087] Figure 4 shows a schematic cross-section through the embodiment of Fig. 3 along section line AA'. As can be seen, the polymer electrolyte fuel cell 1 consists of the components shown in Fig. 1 and rolled up into a hollow cylinder 2, the inner housing 6 and the outer housing 7. The hollow cylinder 2 consists of several layers of the first reaction chamber 10 and the second reaction chamber 20, which are each separated in a gas-tight manner from an adjacent first or second reaction chamber 10, 20 by a polymer electrolyte membrane layer 30a or 30b. The individual layers of the first reaction chamber 10 are also sealed in a gas-tight manner at the cover surfaces of the hollow cylinder 2 by the adhesive 31, which connects the two adjacent polymer electrolyte membrane layers 30a and 30b to one another in a gas-tight manner.Each layer or winding of the first reaction chamber 10 consists in principle of the two first gas diffusion layers 11a and 11b, the first catalyst 12 and the first grid structure 13. The first gas diffusion layers 11a and 11b are arranged on the two sides of the first grid structure 13 and the first catalyst 12 is arranged on the side of the respective first gas diffusion layer 11a or 11b facing away from the first grid structure 13. Each layer or winding of the second reaction chamber 20 consists in principle of the two second gas diffusion layers 21a and 21b, the second catalyst 22 and the second lattice structure 23. The second gas diffusion layers 21a and 21b are arranged on the two sides of the second lattice structure 23 and the second catalyst 22 is arranged on the side of the respective second gas diffusion layer 21a or 21b facing away from the second lattice structure 23.

[0088] The inner housing 6 has an opening 61, which here is designed as an elongated hole extending over a large part of the height of the hollow cylinder 2 along its axis. The opening 61 is connected in a gas-tight manner to the innermost layer of the first reaction chamber 10, so that a fuel gas flowing through the inner housing 6 can enter the first reaction chamber 10. For a better representation of the opening 61, the first catalyst 12 present at this point has been omitted from Fig. 4. The polymer electrolyte layers 30a and 30b, which seal the opening 61 in a gas-tight manner from the environment, e.g., the second reaction chamber 20, are also not visible in Fig. 4 due to the sectional view. In the illustrated embodiment, the inner housing 6 also has a means 62 for closing the opening 61, e.g.a slide which can be pushed in front of the opening 61 by a movement along the direction of the axis of the hollow cylinder 2 such that the opening 61 is closed gas-tight with respect to the first reaction chamber 10 and the entry of a fuel gas into the first reaction chamber 10 is prevented.

[0089] The outer housing 7 has an inner wall 71, an outer wall 72, and an interior space 73 arranged therebetween, as well as an opening 74. The opening 74 is formed in the inner wall 71 and, similar to the opening 61 of the inner housing, here as an elongated hole which extends over a large part of the height of the hollow cylinder 2 along its axis. The opening 74 is connected in a gas-tight manner to the outermost layer of the first reaction chamber 10, so that a fuel gas not converted in the polymer electrolyte fuel cell can escape from the first reaction chamber 10 and flow into the interior space 73 of the outer housing 7. To better illustrate the opening 74, the first catalyst 12 present at this point has been omitted from Fig. 4. The polymer electrolyte layers 30a and 30b, which seal the opening 74 gas-tight against the environment, e.g. the second reaction chamber 20, are also not visible in Fig. 4 due to the sectional view.Similar to the inner housing 6, in embodiments the outer housing 7 can also have a means for closing the opening 74, e.g. a slide which closes the opening 74 in a gas-tight manner with respect to the first reaction chamber 10 and prevents the entry of a fuel gas into the first reaction chamber 10 from the outer housing 7 or the entry of an unreacted fuel gas from the first reaction chamber 10 into the outer housing 7.

[0090] Although not shown in Fig. 4, the inner housing 6 has at least one opening through which a fuel gas can be introduced into the inner housing 6 and supplied to the first reaction chamber 10. If the inner housing 6 is a tube, this opening is realized by the opening of the tube at its ends. Similarly, the outer housing 7 has at least one opening through which an unreacted fuel gas can be discharged from the outer housing 7; this opening is also not shown in Fig. 4.

[0091] Furthermore, Fig. 4 shows the height h2 of the hollow cylinder 2, which is measured along the axis of the hollow cylinder. As shown in Fig. 4, the inner housing 6 and the outer housing 7 can have a greater height than the hollow cylinder 2. However, this is not absolutely necessary. Furthermore, it should be noted that the inner housing 6 and / or the outer housing 7 can extend further along one or both directions that run parallel to the axis of the hollow cylinder 2 and, for example, can also penetrate or enclose several hollow cylinders 2. This will be explained in more detail with reference to Fig. 6A.

[0092] Figure 5A shows a side view of the inner housing 6 with the opening 61, as already explained with reference to Fig. 4. The opening 61 extends over a height hei, which is measured along the axis of the hollow cylinder, and has a width bei, which is measured along the outer circumference of the inner housing 6. The width bei is smaller than the width bioi of the first reaction chamber 10 at the interface between the first reaction chamber 10 and the inner housing 6. Furthermore, the height hei is also smaller than the height hioi of the first reaction chamber 10 at the interface between the first reaction chamber 10 and the inner housing 6. The first reaction chamber 10 thus completely encloses the opening 61.Furthermore, the first reaction chamber 10 is surrounded by the polymer electrolyte membrane layers, which also adjoin the inner housing 6 and are connected to it in a gas-tight manner, so that the first reaction chamber 10 is connected to the inner housing 6 in a gas-tight manner in the region of the opening 61 and a gas from the inner housing 6 can enter exclusively into the first reaction chamber 10 through the opening 61.

[0093] In the illustrated embodiment, the inner housing 6 has an electrically conductive region 63 which extends over the entire height of the inner housing 6, but only over a region of the outer circumference of the inner housing 6. The electrically conductive (or electrically conductive) region 63 is arranged in a region in which the first reaction chamber 10 also borders the inner housing 6. This makes it possible to electrically contact the first reaction chamber 10, i.e. one of the electrically conductive components of the first reaction chamber 10, e.g. the first lattice structure 13 or one or both of the first gas diffusion layers 11a, 11b or the first catalyst 12, via the inner housing 6. For this purpose, the electrically conductive region 63 is connected to a first electrode 8 of the polymer electrolyte fuel cell or can be regarded as the first electrode 8 of the polymer electrolyte fuel cell.

[0094] Furthermore, in Fig. 5A the outer diameter De a of the inner housing 6, which has already been explained above and related to the inner width of the hollow cylinder.

[0095] Figure 5B shows a side view of the inner wall 71 of the outer housing 7 with the opening 74, as already explained with reference to Fig. 4. The opening 74 extends over a height h?4, which is measured along the axis of the hollow cylinder, and has a width b?4, which is measured along the inner circumference of the outer housing 7. The width b?4 is smaller than the width b ai of the first reaction chamber 10 at the interface of the first reaction chamber 10 to the outer housing 7. In addition, the height h?4 is also smaller than the height hio aof the first reaction chamber 10 at the interface between the first reaction chamber 10 and the outer housing 7. The first reaction chamber 10 thus completely encloses the opening 74. Furthermore, the first reaction chamber 10 is surrounded by the polymer electrolyte membrane layers, which also border the inner wall 71 of the outer housing 7 and are connected to it in a gas-tight manner, so that the first reaction chamber 10 is connected to the outer housing 7 in a gas-tight manner in the region of the opening 74 and a gas can only enter the outer housing 7 from the first reaction chamber 10 through the opening 74.

[0096] In the illustrated embodiment, the outer housing 7 has an electrically conductive region 75, which here extends over the entire height of the outer housing 7, but only over a region of the inner circumference of the outer housing 7. The electrically conductive (or electrically conductive) region 75 is arranged in a region in which the second reaction chamber 20 also borders the inner wall 71 of the outer housing 7. This makes it possible to electrically contact the second reaction chamber 20, i.e., one of the electrically conductive components of the second reaction chamber 20, e.g., the second lattice structure 23 or one or both of the second gas diffusion layers 21a, 21b or the second catalyst 22, via the outer housing 7. For this purpose, the electrically conductive region 75 is connected to a second electrode 9 of the polymer electrolyte fuel cell or can be regarded as the second electrode 9 of the polymer electrolyte fuel cell.

[0097] The height of the inner housing 6 and the height of the outer housing 7 are also measured along the axis of the hollow cylinder 2. The electrical energy generated in the polymer electrolyte fuel cell can be dissipated to the outside via the first and second electrodes 8 and 9.

[0098] Furthermore, Fig. 5B shows the inner diameter D?i of the outer housing 7, which has already been explained above and related to the outer width of the hollow cylinder.

[0099] Figure 6A shows a schematic cross-section through a module 100 comprising three polymer electrolyte fuel cells 1a to 1c according to the invention, which have a common inner housing 6 and a common outer housing 7, and Figure 6B shows the electrical circuit diagram of this module. Each fuel cell 1a to 1c thus has a corresponding hollow cylinder 2a, 2b, or 2c, as described above. The inner housing 6 has at least one opening in the region of each fuel cell 1a to 1c, through which a fuel gas can be supplied into the respective first reaction chamber of the corresponding hollow cylinder 2a to 2c.Furthermore, in embodiments, the inner housing 6 also has a means for closing the at least one opening assigned to an individual fuel cell 1a to 1c, so that the supply of fuel gas to each of the fuel cells 1a to 1c can be interrupted separately without impairing the supply of fuel gas to other fuel cells 1a to 1c. The outer housing 7 has at least one opening in the region of each fuel cell 1a to 1c, through which a fuel gas not converted in the respective fuel cell 1a to 1c can be discharged from the respective first reaction chamber of the corresponding hollow cylinder 2a to 2c.In embodiments, the outer housing 7 also includes a means for closing the at least one opening associated with an individual fuel cell 1a to 1c, so that the supply of fuel gas to each of the fuel cells 1a to 1c from the outer housing 7 can be separately prevented. This allows one or more of the fuel cells 1a to 1c to be easily switched off or connected to the module 100, allowing defective fuel cells to be disconnected without switching off the entire module 100, or allowing the amount of energy generated by the module 100 to be controlled.

[0100] In the illustrated embodiment, the inner housing 6 has an electrically conductive region that extends over the entire height of the inner housing 6 and electrically contacts the first reaction chambers of all fuel cells 1a to 1c. Similarly, the outer housing 7 has an electrically conductive region that extends over the entire height of the outer housing 7 and electrically contacts the second reaction chambers of all fuel cells 1a to 1c. The individual fuel cells 1a to 1c are thus connected in parallel. The electrically conductive region of the inner housing 6 is electrically conductively connected to a first electrical connection 101 of the module 100, while the electrically conductive region of the outer housing 7 is electrically conductively connected to a second electrical connection 102 of the module 100.The electrical energy generated by the fuel cells 1a to 1c can be dissipated via the electrical connections 101 and 102.

[0101] Of course, a serial connection of the individual fuel cells can also be realized in embodiments that have a common inner and a common outer housing for several fuel cells.

[0102] Fig. 7A shows a schematic flow chart of an embodiment of the method according to the invention for producing the polymer electrolyte fuel cell according to the invention, and Fig. 7B shows a schematic flow chart of the first step of the method described in Fig. 7A. The illustrated embodiment of the method begins in step S100 with the production of a flat precursor, which already has all components of the first and second reaction chambers as well as the first and second polymer electrolyte membrane layers connected to one another in a gas-tight manner, and thus corresponds to the components shown in Figs. 1A and 1B. For this purpose, as shown in Fig. 7B, two first gas diffusion layers and the first and second polymer electrolyte membrane layers are first provided (steps S110 and S111).Subsequently, a first catalyst is applied to the first and second polymer electrolyte membrane layers and / or to the first gas diffusion layers if the first catalyst is not already contained in the first gas diffusion layers (step S112). Of course, it is also possible for the first catalyst to already be present as a layer on the provided first gas diffusion layers and / or on the first and second polymer electrolyte membrane layers, whereby this step can be omitted. As a result of these first steps, the first catalyst can be present on or in both first gas diffusion layers, or on the first and second polymer electrolyte membrane layers, or on or in only one of the two first gas diffusion layers and on only one of the first and second polymer electrolyte membrane layers, or even on or in all of these layers.In a further method step (S113), two second gas diffusion layers are provided, and subsequently a second catalyst is applied to the first and second polymer electrolyte membrane layers on a side of the first and second polymer electrolyte membrane layers to which the first catalyst is not applied, and / or to the second gas diffusion layers if the second catalyst is not already contained in the second gas diffusion layers (step S114). Here, too, similar to the first catalyst, there are various design options regarding where and when the second catalyst is applied or contained. This step can also be omitted if the second catalyst is already present as a layer on the provided second gas diffusion layers and / or on the first and second polymer electrolyte membrane layers.Furthermore, in step S115, a first and a second electrically conductive and three-dimensional grid structure are provided.

[0103] In a next step (S116), a first reaction chamber is formed by arranging the first gas diffusion layers, the first and second polymer electrolyte membrane layers, and the first lattice structure one above the other such that the first lattice structure is arranged between the two first gas diffusion layers, and one of the two first gas diffusion layers borders the first polymer electrolyte membrane layer or the first catalyst on the first polymer electrolyte membrane layer, and the other of the two first gas diffusion layers borders the second polymer electrolyte membrane layer or the first catalyst on the second polymer electrolyte membrane layer. If the first catalyst is applied as a layer to the first gas diffusion layers, the first catalyst borders the first or second polymer electrolyte membrane layer.After forming the first reaction space, the first and second polymer electrolyte membrane layers are connected to each other in a gas-tight manner at two opposite ends of the first reaction space (step S117).

[0104] In a further step S118, one of the two second gas diffusion layers is bonded to the first polymer electrolyte membrane layer or to the second catalyst applied to the first polymer electrolyte membrane layer such that the second gas diffusion layer is arranged on the side of the first polymer electrolyte membrane layer facing away from the first reaction chamber. "Connecting" here also refers to simply placing the second gas diffusion layer on the first polymer electrolyte membrane layer or also placing the first polymer electrolyte membrane layer or the already formed first reaction chamber on the second gas diffusion layer, wherein the first and second polymer electrolyte membrane layers may or may not already be bonded to one another in a gas-tight manner.Furthermore, in a step S119, the other second gas diffusion layer is bonded to the second polymer electrolyte membrane layer or to the second catalyst applied to the second polymer electrolyte membrane layer such that the second gas diffusion layer is arranged on the side of the second polymer electrolyte membrane layer facing away from the first reaction chamber. Here, too, the same statements apply as above regarding the meaning of the word "bonding." However, in the aforementioned cases, "bonding" can also encompass gluing the corresponding layers (gas diffusion layer, polymer electrolyte membrane layer, or catalyst), although an electrically conductive connection between the corresponding layers must be ensured. Finally, in a further step (S120), the second lattice structure is applied to the other second gas diffusion layer.Although an exemplary sequence of steps is shown here, most of the steps mentioned can also be performed in other sequences or even simultaneously, as long as they do not build on other steps. It is also possible for the second gas diffusion layer to be applied to the second grid structure rather than bonded to the first polymer electrolyte membrane layer.

[0105] Returning to Fig. 7A, the further steps of the method for producing a polymer electrolyte fuel cell according to the invention will now be described. In the illustrated embodiment, in step S200, an inner housing is provided and connected in a gas-tight manner to the first reaction chamber of the sheet-like precursor. The inner housing has at least one opening, and the inner housing and the first reaction chamber are connected to one another in such a way that a gas from the inner housing can enter the first reaction chamber through the at least one opening in the inner housing. In other words, the first reaction chamber is connected to the inner housing in the region of the at least one opening in the inner housing at one of its ends, at which the first and second polymer electrolyte membrane layers are not connected to one another in a gas-tight manner.In a further step (S300), the sheet-like precursor is rolled up to form a hollow cylinder, wherein the second catalyst, the second gas diffusion layers, and the second lattice structure form a second reaction chamber that is open at the top surfaces of the hollow cylinder, and wherein the gas-tightly connected ends of the first and second polymer electrolyte membrane layers are each arranged on the top surfaces of the hollow cylinder. If, as in the illustrated embodiment, the inner housing is already connected to the sheet-like precursor, the sheet-like precursor is rolled up around the inner housing. In other cases, the sheet-like precursor can first be rolled up into a hollow cylinder, and then the first reaction chamber can be connected to the inner housing in a gas-tight manner. It is also possible to carry out the rolling and gas-tight connection simultaneously.

[0106] In a further step (S400) of the method, an outer housing having at least one opening is provided, and the first reaction chamber is connected to the outer housing in a gas-tight manner such that a gas can escape from the first reaction chamber through the at least one opening of the outer housing. This step advantageously takes place after the hollow cylinder has been created by rolling up the flat precursor.

[0107] Fig. 8A to 8D show various steps of the method according to Fig. 7A using cross-sections through the respective product stage. First, the various components of the polymer electrolyte fuel cell are prepared, with the first and second catalysts optionally being applied as layers to, for example, the first and second gas diffusion layers, and arranged one above the other to achieve the arrangement in Fig. 8A. For example, the first polymer electrolyte membrane layer 30a and a first gas diffusion layer 11a, on which the first catalyst 12 is applied, can be applied onto a second gas diffusion layer 21a, on which the second catalyst 22 is applied as a layer. The first lattice structure 13 and another first gas diffusion layer 11b, on which the first catalyst 12 is applied as a layer, are applied over this.Subsequently, the second polymer electrolyte membrane layer 30b and another second gas diffusion layer 21b, onto which the second catalyst 22 is applied as a layer, are applied. All gas diffusion layers 11a, 11b, 21a, and 21b and the layers of the first or second catalyst 12, 22 are arranged such that the layers of the first or second catalyst 12, 22 are adjacent to the first or second polymer electrolyte membrane layer 30a, 30b, respectively. Finally, the second lattice structure 23 is applied. All components are present as flat layers that have large lateral dimensions in the xy plane compared to their thickness in the z direction. The first and second polymer electrolyte membrane layers 30a, 30b protrude at the two ends of the resulting layer stack in the x-direction, of which in Fig.8A only one end is shown, beyond the other layers, but at least beyond the first gas diffusion layers 11 a, 11 b, the layers of the first catalyst 12 and the first lattice structure 13.

[0108] Subsequently, the first and second polymer electrolyte membrane layers 30a, 30b are bonded together in a gas-tight manner, here using the adhesive 31. The result is a flat precursor 80, as shown in Fig. 8B, which has a first reaction chamber 10.

[0109] Subsequently, an inner housing 6, which here is, for example, a tube, is provided and connected to the flat precursor 80. The inner housing 6 has an opening 61 and is connected to the flat precursor 80 at one end of the flat precursor 80, at which the first and second polymer electrolyte membrane layers 30a, 30b are not connected to one another in a gas-tight manner, in such a way that the opening 61 borders the first reaction chamber 10 in the region of the latter. This can be seen in Fig. 8C, wherein the illustration in Fig. 8C is rotated 90° about the z-axis compared to the illustrations in Figs. 8A and 8B. Thus, one end of the flat precursor 80, at which the adhesive 31 is present, can now be seen in a top view.For the sake of clarity and comprehensibility, the layers of the first and second catalyst 12, 22 are not shown here, and the first gas diffusion layers 11a and 11b as well as the first lattice structure 13, which is present beneath the adhesive 31, are shown in dashed lines. The opening 61 of the inner housing 6 also does not extend into the plane of the plan view and is therefore only shown in dashed lines. Already at this stage, the inner housing 6 can be connected in a gas-tight manner to the first reaction chamber 10 by the first and second polymer electrolyte membrane layers 30a, 30b being connected in a gas-tight manner to the inner housing 6 and surrounding and enclosing the opening 61. However, the gas-tight connection of the first reaction chamber 10 to the inner housing 6 can also be established in or after the following steps, e.g., the rolling of the flat precursor 80 onto or around the inner housing 6.

[0110] The result of the step of rolling up the flat precursor is shown in Fig. 8D. The rolling process creates a hollow cylinder 2, and the second reaction chamber 20 is formed by stacking the second gas diffusion layer (21a in Fig. 8C) on top of the second lattice structure (23 in Fig. 8C) and the other gas diffusion layer (21b in Fig. 8C), as well as the respective layers of the second catalyst. The inner housing 6 is arranged inside the hollow cylinder 2, and the gas-tightly connected ends of the first and second polymer electrolyte membrane layers 30a, 30b are located on the two cover surfaces of the hollow cylinder 2, of which only the upper one is visible in Fig. 8D. Thus, the first reaction chamber 10 is sealed off from the cover surfaces of the hollow cylinder 2 in a gas-tight manner, while the second reaction chamber 20 is open at the cover surfaces of the hollow cylinder 2.

[0111] The hollow cylinder 2 is then connected to an outer housing 7, resulting in the polymer electrolyte fuel cell 1 described with reference to Figures 3 and 4. The open end of the first reaction chamber 10 on the outside of the hollow cylinder 2 is connected in a gas-tight manner to the outer housing 7.

[0112] Within the meaning of the invention, the embodiments of the polymer electrolyte fuel cell, a module comprising a plurality of such polymer electrolyte fuel cells or the method for producing a polymer electrolyte fuel cell or individual features thereof can also be combined with one another, as long as they do not exclude one another.

[0113] Reference symbol

[0114] 1, 1a - 1c Po ly me re le ktroly t- B re nnstoffzel I e

[0115] 2, 2a - 2c hollow cylinder

[0116] 3 top surface of the hollow cylinder

[0117] 4 Inner surface of the hollow cylinder

[0118] 5 Outer surface of the hollow cylinder

[0119] 6 Inner casing

[0120] 7 Outer casing

[0121] 8 First electrode of the polymer electrolyte fuel cell

[0122] 9 Second electrode of the polymer electrolyte fuel cell

[0123] 10 First reaction chamber

[0124] 11a, 11b First gas diffusion layer

[0125] 12 First catalyst

[0126] 13 First lattice structure

[0127] 14 First surface of the first reaction chamber

[0128] 15 Second surface of the first reaction chamber

[0129] 20 Second reaction chamber

[0130] 21a, 21b Second gas diffusion layer

[0131] 22 Second catalyst

[0132] 23 Second lattice structure

[0133] 30a, 30b polymer electrolyte membrane layer

[0134] 31 Adhesive

[0135] 61 Opening in inner housing

[0136] 62 Means for closing the opening of the inner housing

[0137] 63 Electrically conductive area of ​​the inner housing

[0138] 71 Inner wall of the outer casing

[0139] 72 Outer wall of the outer casing

[0140] 73 Interior of the outer casing

[0141] 74 Opening in outer casing

[0142] 75 Electrically conductive area of ​​the outer casing

[0143] 80 Flat pre-product

[0144] 100 modules consisting of several polymer electrolyte fuel cells

[0145] 101, 102 Electrical connections of the module bioi Width of the first reaction chamber at the interface to the inner

[0146] Housing bioa Width of the first reaction chamber at the interface to the outer

[0147] Housing at width of opening in inner housing b?4 width of opening in outer housing

[0148] D 2a Outer width of the hollow cylinder

[0149] D 2i Inner width of the hollow cylinder

[0150] De a Outer diameter of the inner housing

[0151] D?i Inner diameter of the outer casing du Thickness of the first gas diffusion layer di2 Thickness of the layer of the first catalyst di3 Thickness of the first lattice structure d2i Thickness of the second gas diffusion layer d22 Thickness of the layer of the second catalyst d23 Thickness of the second lattice structure d3o Thickness of the polymer electrolyte membrane layer h2 Height of the hollow cylinder hioi Height of the first reaction space at the interface to the inner casing hioa Height of the first reaction space at the interface to the outer

[0152] Housing hei Height of the opening in the inner housing h?4 Height of the opening in the outer housing

Claims

Patent claims 1. Polymer electrolyte fuel cell (1, 1a-1c) comprising: a first reaction chamber (10) with two first gas diffusion layers (11a, 11b) and a first electrically conductive and three-dimensional lattice structure (13) arranged between the first gas diffusion layers (11a, 11b) and a first catalyst (12), a second reaction chamber (20) with two second gas diffusion layers (21a, 21b) and a second electrically conductive and three-dimensional lattice structure (23) arranged between the second gas diffusion layers (21a, 21b) and a second catalyst (22), and two hydrogen ion-conducting polymer electrolyte membrane layers (30a, 30b), of which a first polymer electrolyte membrane layer (30a) is arranged on a first surface of the first reaction chamber (10) and a second Polymer electrolyte membrane layer (30b) is arranged on a second surface of the first reaction space (10), wherein the second surface is opposite the first surface,and the two polymer electrolyte membrane layers (30a, 30b) are each connected to one another in a gas-tight manner at two opposite ends of the first reaction chamber (10), wherein the first catalyst (12) is applied to or contained in the side of the first and second polymer electrolyte membrane layers (30a, 30b) facing the first reaction chamber (10) and / or on the first gas diffusion layers (11a, 11b), the second catalyst (22) is applied to or contained in the side of the first and second polymer electrolyte membrane layers (30a, 30b) facing away from the first reaction chamber (10), and / or on the second gas diffusion layers (21a, 21b), the first and second reaction chambers (10, 20) are rolled up adjacent to one another to form a hollow cylinder (2) in such a way that the first reaction chamber (10) is separated from the second reaction chamber (20) within the hollow cylinder (2) by the first and second polymer electrolyte membrane layers (30a,30b) is separated and that on the cover surfaces (3) of the hollow cylinder (2) the second reaction chamber (20) is open and the gas-tight connected ends of the two polymer electrolyte membrane layers (30a, 30b) of the first reaction chamber (10) are arranged, in the interior of the hollow cylinder (2) an inner housing (6) is arranged which has at least one opening (61), and the first reaction chamber (10) is gas-tightly connected to the inner housing (6) such that a gas from the inner housing (6) through the at least one opening (61) of the inner housing (6) into the first reaction chamber, (10) or can exit from the first reaction chamber (10) through the at least one opening (61) of the inner housing (6) into the inner housing (6), and the hollow cylinder (2) is surrounded by an outer housing (7) which has at least one opening (74), and the first reaction chamber (10) is connected to the outer housing (7) in a gas-tight manner such that a gas can exit from the first reaction chamber (10) through the at least one opening (74) of the outer housing (7) into the outer housing (7) or can enter from the outer housing (7) through the at least one opening (74) of the outer housing (7) into the first reaction chamber (10).

2. Polymer electrolyte fuel cell according to claim 1, characterized in that the inner housing (6) is a tube.

3. Polymer electrolyte fuel cell according to claim 1 or 2, characterized in that the inner housing (6) is electrically conductive at least in one region (63) and the at least one electrically conductive region (63) is electrically conductively connected to at least the first or the second lattice structure (13, 23) of the first or the second reaction chamber (10, 20).

4. Polymer electrolyte fuel cell according to one of the preceding claims, characterized in that the outer housing (7) is electrically conductive at least in one region (75) and the at least one electrically conductive region (75) is electrically conductively connected to at least the first or the second lattice structure (13, 23) of the first or the second reaction chamber (10, 20).

5. Polymer electrolyte fuel cell according to one of the preceding claims, characterized in that the polymer electrolyte membrane layers (30a, 30b) are bonded together in a gas-tight manner.

6. Polymer electrolyte fuel cell according to one of the preceding claims, characterized in that the polymer electrolyte membrane layers (30a, 30b) are welded together in a gas-tight manner.

7. Module (100) comprising a plurality of polymer electrolyte fuel cells (1a-1c) according to one of claims 1 to 6, characterized in that at least two of the polymer electrolyte fuel cells (1a-1c) are connected to one another in series or in parallel.

8. Module according to claim 7, characterized in that at least two of the polymer electrolyte fuel cells (1a-1c) have a common inner housing (6) and are arranged one behind the other along the direction along which the inner housing (6) extends.

9. A method for producing a polymer electrolyte fuel cell (1, 1a-1c), comprising the steps: Producing a flat pre-product (80), this step comprising the following sub-steps: • Providing two first gas diffusion layers (11a, 11b), • Providing a first polymer electrolyte membrane layer (30a) and a second polymer electrolyte membrane layer (30b), • Applying a first catalyst (12) to the first and second polymer electrolyte membrane layers (30a, 30b) and / or to the first gas diffusion layers (11a, 11b), if the first catalyst (12) is not already contained in the first gas diffusion layers (11a, 11b), • Providing two second gas diffusion layers (21a, 21b), • Applying a second catalyst (22) to the first and second polymer electrolyte membrane layers (30a, 30b) on one side of the first and second polymer electrolyte membrane layers (30a, 30b) on which the first catalyst (12) is not applied, and / or to the second gas diffusion layers (21a, 21b), if the second catalyst (22) is not already contained in the second gas diffusion layers (21a, 21b), • Forming a first reaction chamber (10) by arranging the first Gas diffusion layers (11a, 11b), the first and the second Polymer electrolyte membrane layer (30a, 30b) and a first electrically conductive and three-dimensional lattice structure (13) one above the other such that the first lattice structure (13) is arranged between the two first gas diffusion layers (11a, 11b) and one of the two first gas diffusion layers (11a, 11b) borders the first polymer electrolyte membrane layer (30a) or the first catalyst (12) on the first polymer electrolyte membrane layer (30a) and the other of the two first gas diffusion layers (11a, 11b) borders the second polymer electrolyte membrane layer (30b) or the first catalyst (12) on the second polymer electrolyte membrane layer (30b), • Gas-tight connection of the first and second polymer electrolyte membrane layers (30a, 30b) at two opposite ends of the first reaction chamber (10), • connecting one of the two second gas diffusion layers (21 a, 21 b) to the first polymer electrolyte membrane layer (30 a) or to the second catalyst (22) applied to the first polymer electrolyte membrane layer (30 a) in such a way that the second gas diffusion layer (21 a, 21 b) is arranged on the side of the first polymer electrolyte membrane layer (30 a) facing away from the first reaction space (10), wherein the connection takes place before or after the formation of the first reaction space (10), • connecting the other second gas diffusion layer (21a, 21b) to the second polymer electrolyte membrane layer (30b) or to the second catalyst (22) applied to the second polymer electrolyte membrane layer (30b) such that the second gas diffusion layer (21a, 21b) is arranged on the side of the second polymer electrolyte membrane layer (30b) facing away from the first reaction space (10), wherein the connecting takes place before or after the formation of the first reaction space (10), and • Applying a second electrically conductive and three-dimensional lattice structure (23) to the other second gas diffusion layer (21a, 21b), - rolling up the flat precursor (80) in such a way that a hollow cylinder (2) is formed, wherein the second catalyst (22), the second gas diffusion layers (21a, 21b) and the second electrically conductive and three-dimensional lattice structure (23) form a second reaction space (20) which is open on the cover surfaces (3) of the hollow cylinder (2), and wherein the gas-tight connected ends of the first and second polymer electrolyte membrane layers (30a, 30b) are each arranged on the cover surfaces (3) of the hollow cylinder (2), Providing an inner housing (6) having at least one opening (61), and gas-tightly connecting the first reaction chamber (10) to the inner housing (6) such that a gas can enter the first reaction chamber (10) from the inner housing (6) through the at least one opening (61) of the inner housing (6) or exit the first reaction chamber (10) through the at least one opening (61) of the inner housing (6) into the inner housing (6), wherein the gas-tight connection takes place before, during or after the rolling up of the flat precursor product (80), and providing an outer housing (7) having at least one opening (74), and gas-tightly connecting the first reaction chamber (10) to the outer housing (7) such that a gas can escape from the first reaction chamber (10) through the at least one opening (74) of the outer housing (7) into the outer housing (7) or can enter from the outer housing (7) through the at least one opening (74) of the outer housing (7) into the first reaction chamber (10), wherein the gas-tight connection takes place after the rolling up of the flat precursor product (80).

10. The method according to claim 9, characterized in that the polymer electrolyte membrane layers (30a, 30b) are bonded together in a gas-tight manner.

11. Method according to claim 9, characterized in that the polymer electrolyte membrane layers (30a, 30b) are welded together in a gas-tight manner.

12. A method for operating a polymer electrolyte fuel cell (1, 1a-1b) according to one of claims 1 to 6, characterized in that a hydrogen-containing fuel gas is introduced into the first reaction chamber (10) via the inner housing (6) or the outer housing (7) and an oxygen-containing oxidation gas is introduced into the second reaction chamber (20) and current is discharged via a first electrode (8) and a second electrode (9), wherein the first electrode (8) is electrically conductively connected to the first electrically conductive and three-dimensional lattice structure (13) and the second electrode (9) is electrically conductively connected to the second electrically conductive and three-dimensional lattice structure (23).

13. The method according to claim 12, characterized in that the polymer electrolyte fuel cell is designed according to claim 3 and the inner housing (6) also serves as the first electrode (8) and / or second electrode (9).

14. Method according to one of claims 12 or 13, characterized in that the polymer electrolyte fuel cell is designed according to claim 4 and the outer housing (7) also serves as the first electrode (8) and / or second electrode (9).

15. Method according to one of claims 12 to 14, characterized in that the outer housing (7) or the inner housing (6) serves to remove unreacted fuel gas from the first reaction chamber (10).

16. Method according to one of claims 12 to 15, characterized in that the outer housing (7) serves to discharge the resulting products.

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