DE102011105072B3 - Retention device for fuel cell for converting chemical energy into electrical power, has membrane arranged between frame elements in form-fit manner, and sealing element arranged on outer portion of one frame element with larger frame width - Google Patents

Abstract

The device (1) has a membrane (2) e.g. ion exchange membrane, arranged between frame elements (1.1, 1.2) in a form-fit manner. The membrane is firmly bonded with the frame elements by a bonding agent (3), where one of the frame elements partially comprises frame width smaller than frame width of the other frame element. A sealing element (5) is arranged on an outer portion of the latter frame element with larger frame width. The frame elements are formed of film-like material, which is formed from plastic or plastic mixture. The bonding agent comprises a liquid or pasty adhesive. The adhesive comprises a cold adhesive and/or a hot adhesive. An independent claim is also included for a method for manufacturing a retention device.

Description

The invention relates to a holding device with a membrane of a membrane electrode assembly for a fuel cell according to the preamble of patent claim 1.

The invention further relates to a method for producing such a holding device according to the preamble of patent claim 8.

Fuel cells convert chemical energy into electrical energy. In general, a fuel cell consists of a membrane-electrode unit, which in particular has a proton-conductive membrane and an anode and a cathode as electrodes in the form of gas diffusion electrodes, wherein the membrane is arranged between the anode and the cathode. The membrane-electrode unit is arranged between two bipolar plates, which are the distribution of reactants for the fuel cell such as fuel and oxidizer through the membrane-electrode assembly and the removal of the reactants provided in this, in each case to the membrane-electrode unit open channels, the removal of the heat of reaction via a guided in separate coolant channels coolant and the establishment of an electrical connection between the anode and cathode. In order to avoid a gas exchange, in particular along the edges of the membrane of the membrane-electrode assembly within the fuel cell, the membrane-electrode assembly is provided, for example with a frame and / or a circumferential seal.

Usually, the membrane or the complete membrane-electrode assembly is embedded between two frame halves and glued to them.

The US 2010/0000679 A1 describes a method for connecting a membrane-electrode assembly to a gas diffusion layer of a fuel cell stack. The method comprises the steps of: applying a catalyst layer to a surface of a polymer electrolyte membrane; Applying a seal to an edge region of the polymer electrolyte membrane; and disposing a gas diffusion layer on a surface of the catalyst layer by adhering a surface of the gasket or a part of the surface of the gasket to an edge portion of the gas diffusion layer by means of a binder.

Furthermore, in the EP 2 095 453 B1 discloses an assembly for a fuel cell membrane electrode assembly (fuel cell MEA). The assembly comprises: a gas diffusion layer (GDL); and a gasket connected to the GDL, the gasket comprising: a first gasket layer; a second sealing layer comprising a sealing material in contact with the first sealing layer and the GDL, the sealing material joining the GDL to the first sealing layer; and an adhesive layer disposed on a surface of the first sealing layer; wherein the sealing material of the second sealing layer penetrates the GDL.

• A) Herstellen eines ersten Halbzeuges durch – Aufbringen einer ersten Ionomerschicht auf einen ersten Träger, – Aufbringen einer Anodenkatalysatorschicht auf die erste Ionomerschicht unter Verwendung einer ersten Katalysatortinte, – Trocknen der Anodenkatalysatorschicht,
• B) Herstellen eines zweiten Halbzeuges durch – Aufbringen einer zweiten Ionomerschicht auf einen zweiten Träger, – Aufbringen einer Kathodenkatalysatorschicht auf die zweite Ionomerschicht unter Verwendung einer zweiten Katalysatortinte, – Trocknen der Kathodenkatalysatorschicht,
• C) Entfernen des ersten und zweiten Trägers von der ersten bzw. der zweiten Ionomerschicht und Verbinden des ersten Halbzeuges mit dem zweiten Halbzeug durch ein Verbinden der ersten Ionomerschicht mit der zweiten Ionomerschicht.

From the DE 10 2005 038 612 A1 For example, a process for preparing bilayer catalyst coated membranes for electrochemical devices is known. The method comprises the steps:

• A) producing a first semifinished product by - applying a first ionomer layer to a first support, - applying an anode catalyst layer to the first ionomer layer using a first catalyst ink, - drying the anode catalyst layer,
• B) producing a second semifinished product by - applying a second ionomer layer to a second support, - applying a cathode catalyst layer to the second ionomer layer using a second catalyst ink, - drying the cathode catalyst layer,
• C) removing the first and second carriers from the first and second ionomer layers, respectively, and bonding the first semifinished product to the second semifinished product by bonding the first ionomer layer to the second ionomer layer.

In the DE 10 2009 039 903 A1 For example, a fuel cell stacking section and a method of assembling the fuel cell section will be described. A fuel cell stack portion includes at least one bipolar plate, at least one MEA plate arranged in a stacking direction adjacent to the bipolar plate to form an electrode region, a gasket, the gasket for sealing the electrode portion, and a spacer portion Spacer portion is supported in the stacking direction on one side by the bipolar plate. The spacer portion is supported in the stacking direction on the other side of the MEA board.

From the DE 103 15 796 A1 For example, a catalyst-coated ionomer membrane and a membrane-electrode assembly having components having different colors are known. The ionomer membrane is coated with catalyst layers on both sides of the membrane surface and has two components. One component is attached to the face of the catalyst coated membrane and one Component is attached to the back surface of the catalyst coated membrane. The two components have different colors.

The invention has for its object to provide a comparison with the prior art improved holding device with a membrane of a membrane electrode assembly for a fuel cell and an improved method for their preparation.

With regard to the method, the object is achieved by the features specified in claim 8 and in terms of the holding device by the features specified in claim 1.

Advantageous embodiments of the invention are the subject of the dependent claims.

In a holding device with a membrane of a membrane electrode assembly for a fuel cell, the membrane is arranged in a form-fitting manner between two frame elements. According to the invention, the membrane is materially connected to the frame elements by means of a binder. According to the invention, one of the frame elements, at least in regions, in particular edge-wise or preferably completely circumferentially, has a smaller frame width than the other frame element, wherein the frame element with the larger frame width projects beyond the frame element with the smaller frame width at least in regions and on an outer section the frame member is arranged with the larger frame width at least one sealing element. The frame members have a rectangular or nearly rectangular outer periphery, wherein within the frame member, a middle cutout, preferably a recess is formed. In this case, the middle section is formed corresponding to the male membrane. Thus, the frame members are formed substantially from a peripheral edge region forming the respective frame width, wherein the edge region preferably comprises an inner and / or outer portion. In addition, the frame member having the smaller frame width may also have a smaller material thickness than the other frame member. Furthermore, the membrane is designed in particular as an ion exchange membrane. In this case, in each case a catalyst layer and / or a gas diffusion layer can additionally be arranged on both sides of the membrane.

The holding device according to the invention enables an improved, preferably media-tight sealing of the membrane, in particular in a joint region of the holding device, against external influences, for. B. gas exchange along the edges of the membrane within the fuel cell. In particular, the sealing effect of the binder is improved because creep processes of the binder are at least reduced, which occur during compression of the frame members with the membrane.

The frame members are arranged one above the other so that they are at least partially or completely circumferentially inside one another exactly fitting one another, so that the frame member with the larger frame width projects beyond the frame member with the smaller frame width in the area to the outside. Alternatively, the frame elements are centered one above the other, so that the frame element with the larger frame width projects beyond the other frame element on both sides.

In a preferred embodiment, at least one or both of the frame elements are divided into sections along their frame width, wherein in particular the outer section of the frame element with the smaller frame width is at least shorter than the outer section of the wider frame element. Alternatively, the outer portion of the frame member having the smaller frame width may be omitted.

This allows in a profitable manner a larger space within the fuel cell, which can be used for example for additional sealing elements or for expanding an already arranged sealing element. In particular, in the alternative embodiment, in which the outer portion of the frame member is omitted with the smaller frame width, a distance of the membrane to the sealing elements can be reduced. For a media-tight sealing of the membrane is improved and a production of smaller-sized fuel cells possible, whereby a maximization of a fuel cell number in a fuel cell stack can be achieved.

To connect the frame members to the membrane, a pasty or liquid adhesive is used as the binder, which is applied as an intermediate layer between the two frame elements. For example, the adhesive is a polymeric adhesive which flows under heat and pressure into the membrane and thus connects the frame members to the membrane.

In a preferred embodiment, the adhesive cures in a media-tight manner, so that the membrane is sealed in a media-tight manner.

The frame elements are each formed from a film-like material. The film-like material has over conventional Frame elements on a lower material thickness. In this case, due to the lower material thickness, a larger installation space for, for example, additional sealing elements is available, by means of which, in addition to an improved sealing of the membrane, tolerances in the production of the holding device and / or the fuel cell can be better compensated. In addition, the holding device by means of the film-like material is easier and less expensive to produce and environmentally friendly recyclable.

Furthermore, the film-like material is formed from a plastic or a plastic mixture. In particular, organic polymers are advantageous, which are innert under the operating conditions of the fuel cell and do not secrete interfering substances. In addition, plastics or plastic mixtures are characterized by a good adhesiveness and a gas-tight or almost gas-tight sealing of the membrane to reactants.

In a method according to the invention for producing such a holding device with a membrane of a membrane-electrode unit for a fuel cell, the membrane is arranged in a form-fitting manner between two frame elements, wherein the membrane is materially connected to the frame elements by means of a binder, wherein one of the frame elements at least partially, in particular edge-wise or preferably completely peripherally has a smaller frame width than the other frame element, the frame element with the larger frame width at least partially surmounting the frame element with the smaller frame width outwards and wherein at least one sealing element is arranged on an outer portion of the frame member with the larger frame width ,

By means of the method according to the invention, an improved media-tight sealing of the membrane, in particular of an ion-conductive region of the membrane, is achieved. In particular, the holding device is easier to manufacture, since a joining accuracy of the individual components of the holding device to each other due to the improved sealing of the membrane can be reduced.

• a) Vorverarbeiten und Bereitstellen eines Rahmenmaterials für die Rahmenelemente,
• b) Heraustrennen eines mittleren Ausschnitts aus den Rahmenelementen zur Ausbildung eines aktiven Bereichs der Membran,
• c) Oberflächenmodifikation der Rahmenelemente jeweils in einem Bereich, der den mittleren Ausschnitt randseitig vollständig umgibt,
• d) Applizieren eines Bindemittels auf den oberflächenmodifizierten Bereich des breiteren Rahmenelements,
• e) Positionieren der Membran auf das breitere Rahmenelement derart, dass dessen mittlerer Ausschnitt vollständig mit der Membran abgedeckt ist,
• f) Applizieren eines weiteren Bindemittels auf einen umlaufenden Randbereich der Membran,
• g) Positionieren des schmaleren Rahmenelements auf die Membran und Verpressen der Rahmenelemente mit der Membran und
• h) Anordnen zumindest eines Dichtelements auf einen äußeren Abschnitt des breiteren Rahmenelements.

The method comprises the following steps:

• a) preprocessing and providing a frame material for the frame elements,
• b) separating out a central section of the frame elements to form an active region of the membrane,
• c) surface modification of the frame elements in each case in an area which completely surrounds the middle cut-out at the edge,
• d) applying a binder to the surface modified portion of the wider frame member,
• e) positioning the membrane on the wider frame member such that its central cutout is completely covered with the membrane,
• f) applying a further binder to a peripheral edge region of the membrane,
• g) positioning the narrower frame member on the membrane and pressing the frame members to the membrane and
• h) arranging at least one sealing element on an outer portion of the wider frame member.

This makes it possible to produce an improved holding device for the membrane in conjunction with an improved adhesive concept with a small number of process steps and a reduction of manual process steps. Thus, it is possible to reduce the manufacturing cost and the manufacturing time of the holding device and thus the fuel cell itself.

For improved adhesion of the binder and thus an improved media-tight sealing of the membrane, the surface modification of the frame elements according to step c) is preferably carried out electrochemically. For example, the surface is modified by means of a so-called corona treatment in which a polarity of the surface is increased and thus a wettability and chemical affinity is improved. Alternatively, the surface is modified by means of a so-called flame pyrolysis (CCVD = Combustion Chemical Vapor Deposition), in which different oxides are deposited on the surface.

Embodiments of the invention are explained in more detail below with reference to drawings.

Showing:

1 1 is a schematic section of a sectional view of a conventional holding device for a membrane of a membrane-electrode assembly;

2 1 schematically shows a method sequence for producing a holding device with a membrane of a membrane-electrode unit,

3 schematically a section of a sectional view of a holding device with a membrane of a membrane-electrode assembly in a first embodiment and

4 schematically a section of a sectional view of a holding device with a membrane of a membrane-electrode assembly in a second embodiment.

Corresponding parts are provided in all figures with the same reference numerals.

1 schematically shows a detail of a sectional view of a conventional holding device 1 with a membrane formed as an ion exchange membrane 2 a non-illustrated membrane electrode assembly for a likewise not shown fuel cell.

The holding device 1 includes two frame elements 1.1 . 1.2 between which the membrane 2 is arranged positively and cohesively.

The frame elements 1.1 . 1.2 For example, are formed from a plastic or plastic mixture, which are innert under the operating conditions of the fuel cell and secrete no interfering substances. Furthermore, plastics or plastic mixtures are characterized by a good adhesion and a media-tight or almost media-tight sealing of the membrane 2 to a bipolar plate and to an active region of the fuel cell.

The frame elements 1.1 . 1.2 each have a rectangular or nearly rectangular outer periphery, wherein within the frame elements 1.1 . 1.2 one middle section each 6 , preferably a recess, is formed. Here is the middle section 6 respectively corresponding to the male membrane 2 formed. Thus, the frame elements 1.1 . 1.2 essentially formed from a peripheral edge region forming a respective frame width B1.1, B1.2, which are formed corresponding to one another.

The frame elements 1.1 . 1.2 In the present representation, they are arranged one above the other in such a way that they lie on top of each other at least partially or completely circumferentially on the inside and outside.

The edge area of the frame elements 1.1 . 1.2 each includes an inner section 1.1.1 . 1.2.1 and an outer section 1.1.2 . 1.2.2 , wherein the frame widths B1.1, B1.2 each of a length of the inner portion 1.1.1 . 1.2.1 and the outer section 1.1.2 . 1.2.2 be formed.

The inner section 1.1.1 . 1.2.1 is in each case one of the membrane 2 facing and the outer section 1.1.2 . 1.2.2 one each of the membrane 2 opposite portion and the edge region of the frame member 1.1 . 1.2 ,

The inner sections 1.1.1 . 1.2.1 are each structured, preferably cranked in the opposite direction and formed in length and shape corresponding to each other. The frame elements 1.1 . 1.2 point inside the inner section 1.1.1 . 1.2.1 different distances to each other.

It is in one of the membrane 2 facing end of the inner sections 1.1.1 . 1.2.1 the distance of the frame elements 1.1 . 1.2 to each other the largest. In this area is a peripheral edge region of the membrane 2 between the inner sections 1.1.1 . 1.2.1 arranged.

Towards the outer sections 1.1.2 . 1.2.2 the distance decreases so that it is smaller than the material thickness of the membrane 2 , This is an optimal fit of the membrane 2 between the frame elements 1.1 . 1.2 ensured.

The outer sections 1.1.2 . 1.2.2 are substantially flat and formed in length and shape corresponding to each other, between them no edge region of the membrane 2 arranged.

For cohesive connection of the membrane 2 and for media-tight sealing of the membrane, in particular in an edge region of the membrane 2 is between the frame elements 1.1 . 1.2 a binder 3 applied, which is preferably a liquid or pasty adhesive. The binder 3 is hereafter referred to as an adhesive 3.1 continued.

As an adhesive 3.1 For example, a cold adhesive and / or a hot-melt adhesive such as acrylate, cyanoacrylate, epoxy resin, EVA, polyethylene and / or polypropylene can be used.

The adhesive 3.1 fills one between the frame elements 1.1 . 1.2 arranged intermediate area 4 completely, in particular a joint area 4.1 , which between a bordered edge region of the membrane 2 and the outer sections 1.1.1 . 1.2.1 the frame elements 1.1 . 1.2 is arranged. This is advantageously prevented that the intermediate area 4 Has cavities in which water deposits, icing or gas transfer occur, the membrane 2 and / or the membrane-electrode unit and thus the fuel cell can damage. In other words, this will cause contamination of the intermediate area 4 , in particular the joint area 4.1 , by reactants such as hydrogen and thus a potentially dangerous short circuit reaction of Reactants (eg., Hydrogen and air) largely avoided.

In order to further seal an interior region of the fuel cell, the holding device comprises 1 two sealing elements 5 , each one on the intermediate area 4 remote surface of the frame elements 1.1 . 1.2 in the area of the outer sections 1.1.2 . 1.2.2 are arranged.

The sealing elements 5 are preferably made of a plastic or plastic mixture, for. As polyethylene or polyethylene naphthalate formed.

During the manufacturing process of the conventional holding device 1 is achieved by pressing the sealing elements 5 against the frame elements 1.1 . 1.2 and pressing the frame elements 1.1 . 1.2 with the membrane 2 the adhesive 3.1 between the frame elements 1.1 . 1.2 displaced, especially during operation of the fuel cell and the resulting temperature fluctuations, in which the adhesive 3.1 not always fully cured. This is also called creeping of the adhesive 3.1 referred to and may lead to a decreasing adhesive effect and leaks in the fuel cell. In addition, this can lead to a reduction in the performance of the fuel cell when the adhesive 3.1 is displaced into unintended areas within the fuel cell and clogged, for example, the membrane-electrode assembly.

To solve the above problems is in 2 a process flow for a method for producing a holding device 1 with a membrane 2 shown.

In a first step a) is for the frame elements 1.1 . 1.2 a frame material provided as a roll and pre-processed accordingly.

The frame material is a foil-like material made of plastic or a plastic mixture. The film-like material is preferably single-layered and has a lower material thickness than conventional frame materials, so that a smaller-sized holding device 1 is inexpensive to produce.

For preprocessing, the frame material is unrolled and the frame elements 1.1 . 1.2 sporadically. For this purpose, for example by means of a cutting unit, not shown, the frame elements 1.1 . 1.2 cut out of the unrolled frame material.

It becomes one of the frame elements 1.1 at least in some areas with a smaller frame width B1.1 than the other frame element 1.2 cut out of the frame material.

Examples of different embodiments of the frame element 1.1 with a smaller frame width B1.1 are in the 3 and 4 shown and described.

Following the separation, the frame elements 1.1 . 1.2 deformed such that they each have a crank, so that the frame elements 1.1 . 1.2 each in an inner section 1.1.1 . 1.2.1 and an outer section 1.1.2 . 1.2.2 according to the description 1 are subdivided, wherein the crank each of the inner portion 1.1.1 . 1.2.1 represents.

The transformation of the frame elements 1.1 . 1.2 can be done for example by cold forming, thermoforming or deep drawing.

Alternatively, for the frame element 1.1 provided a further frame material, which has a lower material thickness than the frame material described above. The pre-processing of the other frame material is carried out as previously described.

In a second step b) are made of the frame elements 1.1 . 1.2 one middle section each 6 cut out, in particular cut out, in which an active region of the membrane 2 or alternatively, the membrane-electrode assembly is formed.

For improved adhesion of the adhesive applied at a later date 3.1 In a third step c) in each case a surface of the frame elements 1.1 . 1.2 , especially in an area that has the middle section 6 completely surrounded at the edge, modified. It will be the surfaces modified, which of the membrane 2 are facing.

The surface modification is preferably carried out electrochemically, for example by means of a so-called corona treatment, in which a polarity of the surface is increased and thus a wettability and chemical affinity is improved. Alternatively, the surface is modified by means of a so-called flame pyrolysis (CCVD = Combustion Chemical Vapor Deposition), in which different oxides are deposited on the surface.

Alternatively, it is possible to carry out the surface modification before step b).

In a fourth step d) is applied to the modified surface of the wider frame element 1.2 on an area, the middle section 6 completely surrounds an adhesive 3.1 applied. Applying the glue 3.1 For example, by means of a screen printing method, by means of an offset printing method and / or by means of a jet method analogous to an ink jet method, also called ink-jet method, take place, wherein instead of the ink, for example, the adhesive 3.1 is sprayed. The adhesive 3.1 Alternatively, it is already on a carrier film, for example a protective film. Preferably takes place after application of the adhesive 3.1 no pre-crosslinking of the adhesive 3.1 on the modified surface of the wider frame member 1.2 instead, leaving this with another glue 3.1 , which in a sixth step f) on the membrane 2 is applied, optimally connects and thus adhesion to the frame elements 1.1 . 1.2 more preferably over a full life of the fuel cell is possible.

Selective application of the adhesive 3.1 allows a targeted and high-precision adhesive application, so that the adhesive 3.1 can be applied in an optimal amount and distribution. This allows targeted strength and rigidity of the fixture 1 be achieved. Furthermore, the selective application of the adhesive allows 3.1 a reduced thickness of the holding device 1 and thus the fuel cell, whereby more fuel cells can be arranged within a given space.

In a fifth step e), the membrane 2 such on the wider frame element 1.2 positioned that middle section 6 of the frame element 1.2 completely with the membrane 2 is covered. In a preferred embodiment, the membrane 2 already provided with at least one catalyst layer.

In a sixth step f) is applied to a peripheral edge region of the membrane 2 another glue 3.1 analogous to the application of the adhesive 3.1 on the frame element 1.2 applied. It is both on the frame element 1.2 as well as on the edge area of the membrane 2 the same glue 3.1 applied. Alternatively, different adhesives 3.1 used.

By means of the application of the further adhesive 3.1 on the membrane 2 a short circuit of reactants is largely avoided and an optimal embedding of the membrane 2 in the holding device 1 allows. In addition, due to the applied adhesive 3.1 a material shrinkage or an increase in material of the membrane 2 , z. B. swelling, counteracted during the operating time of the fuel cell. It is also possible that the adhesive 3.1 this material changes elastically follows, so that a seal of the membrane 2 preferably ensured over almost complete life of the fuel cell.

Alternatively, the other adhesive 3.1 also on the modified surface of the narrower frame element 1.1 be applied.

In a seventh step g) becomes the narrower frame element 1.1 provided with its modified surface on the modified surface of the wider frame member 1.2 and with the middle section 6 precisely fitting over the edge area of the membrane 2 is positioned, leaving a loss of active area of the membrane 2 and a consumption of space between the joint area 4.1 and the sealing elements 5 kept as low as possible.

Subsequently, the narrower frame element 1.1 under the application of a pressing force with the membrane 2 pressed. This will be the frame elements 1.1 . 1.2 and the membrane arranged between them 2 laminated together, leaving a peripheral area of the membrane 2 between the frame elements 1.1 . 1.2 is enclosed.

The pressing can be done by means of a roller press, belt press and / or plate press. In one embodiment, the frame elements 1.1 . 1.2 and / or the membrane 2 during pressing at least partially heated and / or cooled.

This is followed by an arrangement of at least one sealing element in an eighth step h) 5 , preferably two sealing elements 5 , each one on the intermediate area 4 remote surface of the wider frame element 1.2 in the area of the outer section 1.2.2 , This is done for example by means of gluing and subsequent pressing of the sealing element 5 against the frame elements 1.1 . 1.2 , z. B. by means not shown bipolar plates. The application of the sealing element 5 can be used both before and after pressing the frame elements 1.1 . 1.2 with the membrane 2 respectively. Alternatively, it is also possible, the sealing element 5 during the manufacture of the frame elements 1.1 . 1.2 integrate into this, so that the sealing element 5 integral with the wider frame element 1.2 is formed. This allows high production flexibility.

The 3 and 4 show a holding device 1 with a membrane 2 prepared according to the method according to 2 in a first and a second embodiment.

In the first preferred embodiment, the outer portion 1.1.2 of the frame element 1.1 shorter than the outer portion 1.2.2 of the other frame element 1.2 , The frame elements 1.1 . 1.2 are arranged one above the other so that they are at least partially, in particular edge-to-edge, or preferably completely circumferentially inside one another exactly fitting one another, so that the wider frame element 1.2 the frame element 1.1 surmounted in the area concerned.

The holding device 1 has two sealing elements 5 which is on two opposite surfaces within the wider frame member 1.2 in the area of the outer section 1.2.2. are arranged.

In the second embodiment, the outer portion is omitted 1.1.2 of the frame element 1.1 so this is just an inner section 1.1.1 having. The frame elements 1.1 . 1.2 are arranged one above the other so that they are at least partially, in particular edge-to-edge, or completely encircling inside superimposed on each other, so that the wider frame element 1.2 the frame element 1.1 surmounted in the area concerned.

The holding device 1 also has two sealing elements 5 on which on opposite surfaces of the wider frame member 1.2 in the area of the outer section 1.2.2. are arranged.

In addition, the frame element 1.1 have a lower material thickness than the wider frame member 1.2 , For example, has the frame element 1.1 a material thickness of less than 25 microns and the wider frame element 1.2 a material thickness between 50 and 100 microns. For a further reduction of costs, space and weight is possible in a particularly advantageous manner.

In an alternative, not shown embodiment, the frame members 1.1 . 1.2 centered on top of each other, leaving the wider frame element 1.2 the frame element 1.1 surmounted on both sides.

In particular, by means of the second embodiment in a profitable manner, the space within the fuel cell can be increased, which, for example, for additional sealing elements 5 or for expanding the already arranged sealing element 5 is usable. In addition, there is a distance between the bordered edge region of the membrane 2 and the sealing elements 5 reducible.

Claims (10)

Holding device ( 1 ) with a membrane ( 2 ) of a membrane electrode assembly for a fuel cell, wherein the membrane ( 2 ) between two frame elements ( 1.1 . 1.2 ), characterized in that the membrane ( 2 ) with the frame elements ( 1.1 . 1.2 ) by means of a binder ( 3 ) is materially connected, wherein one of the frame elements ( 1.1 ) at least partially has a smaller frame width (B1.1) than the other frame element ( 1.2 ), wherein the frame element ( 1.2 ) with the larger frame width (B1.2) the frame element ( 1.1 ) with the smaller frame width (B1.1) at least partially surmounted outwards and wherein on an outer portion ( 1.2.2 ) of the frame element ( 1.2 ) with the larger frame width (B1.2) at least one sealing element ( 5 ) is arranged. Holding device ( 1 ) according to claim 1, characterized in that the frame elements ( 1.1 . 1.2 ) are arranged one above the other such that they are at least partially or completely circumferentially inside one another precisely fitting one above the other, so that the frame element ( 1.2 ) with the larger frame width (B1.2) the frame element ( 1.1 ) with the smaller frame width (B1.1) in the area concerned surmounted to the outside. Holding device ( 1 ) according to claim 1 or 2, characterized in that at least one or both frame elements ( 1.1 . 1.2 ) along its frame width (B1.1, B1.2) into sections ( 1.1.1 . 1.1.2 . 1.2.1 . 1.2.2 ), in particular the outer portion ( 1.1.2 ) of the frame element ( 1.1 ) with the smaller frame width (B1.1) is at least shorter than the outer portion ( 1.2.2 ) of the wider frame element ( 1.2 ). Holding device ( 1 ) according to claim 1, characterized in that the binder ( 3 ) a liquid or pasty adhesive ( 3.1 ). Holding device ( 1 ) according to claim 4, characterized in that the adhesive ( 3.1 ) media-hardening. Holding device ( 1 ) according to one of the preceding claims, characterized in that the frame elements ( 1.1 . 1.2 ) are each formed from a film-like material. Holding device ( 1 ) according to claim 6, characterized in that the film-like material is formed from a plastic or a plastic mixture. Method for producing a holding device ( 1 ) with a membrane ( 2 ) of a membrane electrode assembly for a fuel cell according to any one of claims 1 to 7, wherein the membrane ( 2 ) between two frame elements ( 1.1 . 1.2 ), the membrane ( 2 ) with the frame elements ( 1.1 . 1.2 ) by means of a binder ( 3 ) is materially connected, wherein one of the frame elements ( 1.1 ) at least partially has a smaller frame width (B1.1) than the other frame element ( 1.2 ), wherein the frame element ( 1.2 ) with the larger frame width (B1.2) the frame element ( 1.1 ) with the smaller frame width (B1.1) at least partially surmounted outwards and wherein on an outer portion ( 1.2.2 ) of the frame element ( 1.2 ) with the larger frame width (B1.2) at least one sealing element ( 5 ) is arranged. Method according to claim 8, characterized by the following steps: a) preprocessing and provision of a frame material ( 6 ) for the frame elements ( 1.1 . 1.2 ), b) cutting out a middle section ( 6 ) from the frame elements ( 1.1 . 1.2 ) for forming an active region of the membrane ( 2 ), c) surface modification of the frame elements ( 1.1 . 1.2 ) in each case in an area which the middle section ( 6 ) completely surrounds the edge, d) applying a binder ( 3 ) on the surface-modified area of the wider frame element ( 1.2 ) e) Positioning the membrane ( 2 ) to the wider frame element ( 1.2 ) such that its middle section ( 6 ) completely with the membrane ( 2 ), f) applying a further binder ( 3 ) on a peripheral edge region of the membrane ( 2 ), g) positioning the narrower frame element ( 1.1 ) on the membrane ( 2 ) and pressing the frame elements ( 1.1 . 1.2 ) with the membrane ( 2 ) and h) arranging at least one sealing element ( 5 ) on an outer section ( 1.2.2 ) of the wider frame element ( 1.2 ). Method according to claim 9, characterized in that the surface modification of the frame elements ( 1.1 . 1.2 ) takes place electrochemically.

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