WO2022106235A1

WO2022106235A1 - Method for producing a membrane-electrode assembly, and membrane-electrode assembly for a fuel cell

Info

Publication number: WO2022106235A1
Application number: PCT/EP2021/080909
Authority: WO
Inventors: Jürgen Kiener; Stefan Kiener
Original assignee: Lacom Gmbh
Priority date: 2020-11-19
Filing date: 2021-11-08
Publication date: 2022-05-27
Also published as: DE102020130578A1; EP4248510A1

Abstract

The invention relates to a method and to a membrane-electrode assembly (25) for a fuel cell, comprising a first and second support film (26, 27), each of which has cut-outs (29), with a membrane film blank (31) that comprises an electrolyte membrane (14) as a support layer, on both sides of which a catalyst layer is provided. A peripheral edge (32) of the electrolyte membrane (14) is formed with respect to the catalyst layers (16, 17), wherein the exterior of the peripherally protruding edge (32) of the membrane film blank (31) is rigidly connected to the support film (26, 27) face facing the edge (32).

Description

Verfahren zur Herstellung einer Membran-Elektroden-Anordnung sowie eine Membran-Elektroden-Anordnung für Method for producing a membrane electrode assembly and a membrane electrode assembly for
eine Brennstoffzellea fuel cell

The invention relates to a method for producing a membrane-electrode assembly for a fuel cell, which has a multi-layer structure, and to such a membrane-electrode assembly for a fuel cell.

US 2010/0151350 A discloses a structure for a membrane electrode assembly and a method for its production. In this membrane-electrode assembly, a carrier layer with a supporting film applied thereto is fed to a pair of rotary die-cutting rollers in order to make a cutout in the supporting film. The carrier layer with the cut section is then pulled off and the supporting film is fed to a processing station in which blanks of an electrolyte membrane are applied to the supporting film. These cuts of the electrolyte membrane are obtained from a so-called CCM membrane. This electrolyte membrane is aligned with the cutout in the first support film. The residual strip from which the electrolyte membrane was cut out is discharged.

A second support film with cutouts is then applied to the opposite side of the first support film, the cutouts of which are aligned with those of the first support film. The electrolyte membrane is interposed. A further carrier layer with catalyst layers is then cut in a pair of rotary die-cutting rollers. Thereafter, the support layer with the cut catalyst layers is applied to each side of the electrolyte membrane. The respective carrier layer is then peeled off so that the catalyst layer remains on the electrolyte membrane. Furthermore, the second supporting film is bonded to the first supporting film by an adhesive layer, with the electrolyte membrane not being bonded to the first and second supporting film in a region in which the electrolyte membrane is arranged between the first and second supporting film.

The invention is based on the object of proposing a method for producing a membrane-electrode assembly and a membrane-electrode assembly in which the production costs are reduced in order to enable better market penetration for fuel cell technology.

This object is achieved by a method for producing a membrane electrode assembly for a fuel cell,

in which a first supporting film is provided as web material,

in which cutouts are made in the first supporting film one after the other and at a distance from one another,

in which the support film provided with cutouts is fed to a processing station,

in which a membrane foil is fed to the processing station, which comprises a strip-shaped electrolyte membrane on which catalyst layers are applied on both sides in a format,

in which the membrane foils are cut into membrane foil blanks in the processing station, so that a peripheral edge of the electrolyte membrane remains opposite the format of the catalyst layers,

in which the membrane foil cuts are aligned and applied to the cutouts in the first support foil,

in which a second supporting film is provided as web material,

in which sections aligned at a distance from one another are successively introduced into the second supporting film,

in which the second supporting film is aligned and applied to the first supporting film with the cutouts facing the catalyst layers of the membrane film blanks opposite the first supporting film, and

in which the first and second supporting film with the membrane film cuts arranged between them are firmly connected to one another to form a film composite.

This method has the advantage that the production of the membrane-electrode assembly is made possible in an automated process and thus high processing speeds and quantities can be achieved.

The first and/or the second supporting film are preferably provided without a carrier layer. This enables further process optimization.

Advantageously, the first and/or second supporting film is provided with an adhesive coating on one side. As a result, the individual subsequent layers can be applied and prefixed directly thereon. Alternatively, a layer of adhesive can be applied to one side of the first and/or second supporting film in a gluing station.

In a further production step, the cutouts are preferably introduced into the first supporting film by punching or laser cutting before it is fed into the processing station. Both manufacturing options can be used in a continuous process.

The cut-outs can be made in the second supporting film by punching or laser cutting before it is fed to the membrane film blanks equipped with the first supporting film. The redundancy of the workstations can in turn make it possible to reduce the costs of the manufacturing process.

In the processing station, the membrane blanks are preferably cut with a peripheral edge compared to the catalyst layers applied to both sides of the electrolyte membrane, so that the peripheral edge is formed with an overhang of the same width compared to all side edges of the format of the catalyst layers. As a result, the membrane foil blanks can be securely accommodated between the two supporting foils. In addition, a high level of tightness can be created, which is advantageous when using a plurality of membrane electrode assemblies arranged one above the other in a fuel cell.

The catalyst layers can be applied to the electrolyte membrane in a square or rectangular format, and the cutouts in the first and second support foils are preferably adapted to the square or rectangular format of the catalyst layers. Advantageously, the size of the cutouts that are made in the first and second supporting foil is the same as or slightly smaller than the format of the catalyst layers. As a result, required tolerances can be well maintained. For example, the catalyst layers can be introduced with a tolerance of +/- 0.1 mm between the edges of the cutouts in the support foils. This precision when introducing the catalyst layers of the membrane foil cuts into the cutouts of the supporting foils is a decisive factor for the performance of the fuel cell. As a result, higher packing densities and thus a reduced size of the fuel cell can be made possible.

Furthermore, the edge of the membrane film blank that protrudes beyond the format of the catalyst layers is preferably glued on both sides between the first and second supporting film. As a result, a high degree of tightness of such a membrane electrode assembly can be ensured.

Advantageously, at least one gas diffusion layer is applied simultaneously or sequentially to the respective catalyst layer on each side of the membrane foil cuts of the foil composite produced.

Before the gas diffusion layer is applied, an adhesive layer is preferably applied to the respective catalyst layer of the membrane foil cut, in particular in an adhesive coating station. This also enables a continuous manufacturing process.

In particular, the gas diffusion layer is cut to size in a further processing station and applied to the respective catalyst layer of the membrane foil cuts and glued to them. In this further processing station, for example, the gas diffusion layers can be cut to size by a pair of rotary die-cutting rollers and then applied.

According to a first preferred embodiment for producing the membrane foil blanks, the processing station is produced by a pair of vacuum punching rollers, the membrane foil blanks being cut to size with a rotary die cutter and then applied to the first supporting film with a vacuum counter-punching roller or positioned in the cutout of the first supporting film.

Alternatively, the processing station can be cut by a pair of rotary die-cutting rollers, with holding webs being formed between the membrane foil blank and the remaining web material, and with a squeezing and laminating roller arranged downstream of the pair of rotary die-cutting rollers in the conveying direction, the membrane foil blanks are pressed out and positioned in the cutouts of the first supporting foil and applied to the backing sheet.

Furthermore, the mutually opposite longitudinal edges of the film composite produced are preferably cut to a constant width, preferably by means of a laser. As a result, the edges of the support films lying one on top of the other are cut at the same time, so that their edges are congruent.

Advantageously, the film composite produced can be separated into membrane-electrode assemblies, in particular after the film composite has been trimmed to a constant width. For example, the separation can be made possible by punching or by means of a laser by cross-cutting.

A further preferred embodiment of the method provides that the first supporting film, the second supporting film and the membrane film are provided and supplied as semi-finished products on a roll. This enables a continuous production process, which also enables a high degree of precision in the alignment of the individual layers or the cutouts of the support foils with respect to the catalyst layers of the membrane foil.

The application of the membrane foil cuts to the first supporting foil and the feeding of the second supporting foil to the first supporting foil is advantageously controlled with a continuous web speed. As a result, a large number can be manufactured and thus the manufacturing costs can be reduced.

The object on which the invention is based is also achieved by a membrane-electrode assembly, in which a first and second support film each have a cutout and a membrane film cut, which includes an electrolyte membrane on which a catalyst layer is provided on both sides and opposite the catalyst layers applied on both sides a peripheral edge protruding from the electrolyte membrane is formed, the peripherally protruding edge of the membrane foil blank being firmly connected to the side of the supporting foil pointing towards the peripheral edge. As a result, this membrane electrode assembly can be highly sealed. Advantageously, the peripheral edge is glued on both sides to the respective supporting film.

According to a further preferred embodiment, the section of the first supporting film and the section of the second supporting film are aligned congruently with one another. As a result, a consistently dimensioned overlapping area between the respective support films and the outer peripheral edge of the membrane film blank can be made possible.

The invention and other advantageous embodiments and developments thereof are described and explained in more detail below with reference to the examples shown in the drawings. The features to be found in the description and the drawings can be used according to the invention individually or collectively in any combination. Show it:

Figure 1 shows a basic structure of a known fuel cell,

FIG. 2 shows a schematic sectional view of a film composite for a membrane electrode assembly,

FIG. 3 shows a schematic view of the film composite according to FIG. 2,

FIG. 4 shows a schematic side view of a system for producing the membrane electrode assembly,

FIG. 5 shows a schematic side view of an alternative embodiment to FIG. 4,

FIG. 6 shows a schematic sectional view of a further embodiment of the membrane electrode assembly,

FIG. 7 is a schematic view from above of the alternative embodiment according to FIG. 6, and

FIG. 8 shows a schematic partial view of the system for producing the alternative embodiment of the membrane electrode assembly according to FIG.

In Figure 1, a fuel cell 11 is shown schematically with respect to its basic components. Catalyst layers 16, 17 are provided on both sides of an electrolyte membrane 14, the hydrogen being separated into hydrogen ions H ⁺ and electrons e ^- on the catalyst layer 16 (anode). The electrolyte membrane 14 allows only one passage for hydrogen ions or protons and water to get to the further catalyst layer 17, the cathode. Preferably, the electrodes travel through an electrical circuit in the form of an electrical current. This can be transferred to a battery, in particular a rechargeable battery. Gas diffusion layers (GDL) 18 , 19 are provided on both sides of the catalyst layers 16 , 17 . A first plate and a

second plate

21, 22 are provided outside of these gas diffusion layers 18, 19, respectively. Hydrogen can flow through the first plate 21 . Oxygen can flow through the second plate 22 , water and heat being formed on the surface of the catalyst layer 17 and dissipated via this second plate 22 .

This fuel cell 11 can be combined and stacked with a large number of other fuel cells 11 . The number of stacked fuel cells 11 determines the total voltage or mains voltage, with the surface area of the individual fuel cells determining the total current. The total electrical power generated by such a stack of fuel cells 11 can be determined by the product of voltage and current.

FIG. 2 shows a schematic sectional view of a composite film 35 for producing membrane electrode assemblies 25 (MEA). The film composite 35 is separated into membrane-electrode assemblies 25 by making separating cuts 36 . The membrane-electrode assemblies 25 comprise at least the electrolyte membrane 14 and the catalyst layers 16, 17 as well as a first and

second support film

26, 27. The first and

second support films

26, 27 are not shown in FIG. 1 for the sake of simplicity.

This first support film 26 is usually referred to as subgasket 1 and the second support film 27 as subgasket 2 . These have the task of supporting the electrolyte membrane 14 mechanically and/or statically, without thereby influencing the ongoing electrochemical processes of the fuel cell 11 . This membrane electrode assembly (MEA) 25 is constructed as follows:

The first supporting film 26 and the second supporting film 27 each have cutouts 29 . A membrane foil blank 31 is provided between the first and second support foils 26 , 27 . This membrane foil blank 31 consists of an electrolyte membrane 14, which is preferably designed as a polymer electrolyte membrane. The catalyst layers 16 , 17 are provided on both sides of the electrolyte membrane 14 . The catalyst layer 16 forms the anode. The catalyst layer 17 forms the cathode. These catalyst layers 16, 17 are preferably congruently one on top of the other and are formed with the same format. For example, a rectangular format is provided, alternatively a square format can also be formed. The membrane foil blank 31 includes a peripheral edge 32 which consists of the electrolyte membrane 14 . This peripheral edge 32 extends completely around the catalyst layers 16, 17. Preferably, the width of the edge 32 along each longitudinal side of the format of the catalyst layers 16, 17 is of the same size. The membrane foil blank 31 is arranged with the

catalyst layer

16, 17 in the respective cutout 29 of the first and second supporting

foil

26, 27. The peripheral edge 32 extends beyond the cutouts 29 between the first supporting film 26 and the second supporting film 27 . As a result, an overlapping area 33 is formed between the peripheral edge 32 and each side of the first and

second support film

26 , 27 associated with the peripheral edge 32 . In this overlapping area 33, the peripheral edge 32 is firmly connected to the first and second supporting

film

26, 27. An adhesive connection is preferably provided. Furthermore, outside of the peripheral edge 32, the first and

second support films

26, 27 are firmly connected directly to one another, in particular glued.

The cutouts 29 in the first and second supporting

film

26, 27 are the same in size or format as the areal extent of the catalyst layers 16, 17. The cutouts 29 can also be only slightly smaller than the format of the catalyst layers 16, 17, so that the edges of the catalyst layers 16, 17 are directly adjacent to the edges of the cutouts 29.

FIG. 4 shows a schematic side view of a system 41 for producing the membrane-electrode assembly 25 from a film composite 35 according to FIGS. The first supporting film 26 is preferably provided on a roll 42 . This first supporting film 26 is preferably free of a carrier layer. This first supporting film 26 is stored on the roll 42 as web material with a predetermined width. This web material is fed to a gluing station 44 . In this gluing station 44 a layer of adhesive is applied to one side of the supporting film 26 . Alternatively, a first supporting film 26 with an adhesive layer can already be stored on the roll 42 and pulled off.

In a subsequent processing step, the cutouts 29 are introduced successively and at a predetermined distance from one another. For example, a laser cutting station 46 is shown. Alternatively, a stamping processing station for producing the cutouts 29 can also be provided. Furthermore, alternatively, the gluing station 44 and the station 46 for punching out the cutouts 29 can also be interchanged in their order.

A membrane film 49 is processed in a subsequent processing station 48 . This membrane foil 49 is in turn preferably provided on a roll 50 . This membrane foil 49 consists of the electrolyte membrane 14, on both sides of which the catalyst layers 16, 17 are applied at predetermined intervals and congruently opposite one another. This membrane film 49 is fed to a pair of vacuum punching rollers. A membrane foil blank 31 is punched out of the membrane foil 41 by means of a rotary die-cutting roller 51 . The punching takes place in such a way that the peripheral edge 32 is formed outside of the catalyst layers 16 , 17 . The resulting punched-out membrane foil 49 is wound up to form a further roll 53 . The membrane foil blanks 31 punched out by the rotary punching roller 51 are transferred to a counter-rotating vacuum counter-punching roller 52, which then positions the

catalyst layer

16, 17 facing the first support film 26 in the cutout 29 with a precise fit and inserts it. At the same time, the peripheral edge 32 of the membrane foil blank 31 is supported on the first supporting foil 26 adjacent to the cutout 29 . Due to the application of the layer of adhesive, a first adhesion of the peripheral edge 32 of the membrane foil blank 31 to the first supporting foil 26 can be provided.

Downstream of this processing station 48 there is a supply of the second supporting film 27 . This second supporting film 27 is in turn provided and drawn off from a roll 57 as web material. This second supporting film 27 is also preferably provided on the roll 57 without a backing layer. The second support roller 27 can be fed to a gluing station 44 if the second support roller 27 is not already provided with a layer of adhesive. The cutouts 29 are then successively made in the second supporting film 27, for example using the laser cutting station 46. The second supporting film 27 is then fed to the first supporting film 26 via deflection rollers 59 . The feed of the second support film 27 is controlled and aligned in such a way that the respective cutouts 29 in the second support film 27 are aligned with the catalyst layers 16, 17 pointing upwards, so that these catalyst layers 16, 17 are positioned in the cutout 29 of the second support film 27 .

In a subsequent station 61, the supporting

films

26, 27 and the membrane film blank 31 arranged between them, in particular the peripheral edge 32, can be firmly connected to one another. In this station 61, the action of heat or UV crosslinking of the adhesive preferably takes place in order to bond the first and second punched foils 26, 27 and the edge 32 of the membrane foil blank 31 arranged between them. This finished composite film 35 is formed in five layers, for example.

Subsequently, in a further processing station 63, the longitudinal edges of the first and second supporting foils 26, 27 can be trimmed, so that this membrane-electrode assembly 25 has a constant width over its length.

Subsequently, in a processing station 65, the membrane-electrode assemblies 25 can be separated, which up to this point in time have been in the form of a multi-layer film composite in the form of a web. These individual membrane-electrode assemblies 25 can be supplied to a magazine or can be transferred to further downstream processing stations.

An alternative embodiment of the method for producing a membrane electrode assembly 25 is shown in FIG. In this embodiment, the processing station 48 for feeding the membrane foil blanks 31 onto the cutouts 29 in the first supporting foil 26 is different. Otherwise, reference can be made to the embodiments described above. This processing station 48 comprises a pair of rotary die-cutting rollers with a rotary die-cutting roller 67 and a counter-punching roller 68, between which the supplied membrane film 49 is processed. In this case, the membrane foil blank 31 is cut into the membrane foil 49 , with individual webs or retaining webs remaining, so that the membrane foil blank 31 is still held within the membrane foil 49 . These webs are thin so that they allow the membrane foil sections 31 to be easily detached from the membrane foil 49 by tearing them off. This removal is effected by a squeezing and laminating roller 69 downstream of the pair of rotary die-cutting rollers, through which the membrane foil blank 31 is transferred into the cut-out 29 of the first die-cut foil 26, with the membrane foil blank 31 being detached from the membrane foil 49 by tearing off the holding webs.

The composite film 35 shown in FIGS. 2 and 3 is present after the station 61 or after the processing station 63 and before it is separated by the processing station 65 . The distances between the cutouts 29 in the first and second support foils 26, 27 seen in the longitudinal direction and thus the positioning of the membrane foil cuts 31 between the punched foils 26, 27 are designed in such a way that a separating cut 36 positioned centrally between two cutouts 29 (Figures 2 and 3 ) or cross section for separating the membrane electrode assemblies 25 already has a final format for further processing.

FIG. 6 shows a schematic sectional view of the membrane electrode assembly 25 according to FIG. 2 after a further processing step. FIG. 7 shows a view of the sectional view according to FIG. These gas diffusion layers 18, 19 have the task of evenly distributing the gases supplied by the

plates

21, 22, namely hydrogen and oxygen, over the surface. These gas diffusion layers 18, 19 can consist, for example, of chopped carbon fibers which are processed into a suspension in a binder polymer, subsequently dried and impregnated, for example with a duroplastic resin. The applied resin can then be graffitied to increase durability. An adhesive coating, in particular in the form of adhesive beads, is applied to the catalyst layers 16, 17 in order to connect the gas diffusion layers 18, 19 to the catalyst layers 16, 17 to form a common film composite 35. These gas diffusion layers 18, 19 correspond in size or format to the catalyst layers 16, 17.

FIG. 8 shows a schematic view of the system according to FIG. 4 or FIG. 5, a processing station 74 for applying the gas diffusion layers 18, 19 is shown.

In a first step, adhesive application devices 76 are provided on both sides of the composite film 35, by means of which adhesive is applied to the catalyst layers 16, 17, preferably over the entire surface. The processing station 74 with a pair of vacuum rotary die-cutting rollers can then in turn be provided on both sides of the film composite 75 . The gas diffusion layers 18, 19 are provided as web goods on a roll 78. The gas diffusion layers 18, 19 are fed to the pair of vacuum rotary die-cutting rollers, so that the gas diffusion layers 18, 19 are cut to size by the rotary die-cutting roller 51 in the format of the catalyst layers 16, 17 or cutouts 29. A blank of the gas diffusion layers 18, 19 is then applied to the catalyst layers 16, 17 via the vacuum roller 52 and glued to them. This is done sequentially
or on both sides by opposing vacuum rotary die-cutting roller pairs. As a result, a membrane electrode assembly 25 is produced, which is designed in seven layers or with seven layers. The membrane electrode assembly 25 is then separated by cross cutting via the processing station 63.

The methods described here have the advantage that the layers or plies for producing the membrane electrode assembly 25 are all provided as rolled goods. As a result, the individual layers can be processed continuously and the layers can be brought together so that they fit together precisely for the production of the membrane-electrode assembly 25 . In particular, this method aligns and positions a

catalyst layer

16, 17 of the membrane sheet blank 31 with a precise fit to the cutout 29 of the first supporting sheet 26, and then a section 29 of the second supporting sheet 27 is aligned and positioned with a precise fit to the

second catalyst layer

17, 16 of the membrane sheet blank 31. The cutouts 29 of the first and second supporting foils 21, 22 are aligned congruently with one another.

Claims

Method for producing a membrane electrode assembly (25) for a fuel cell (11),

- in which a first supporting film (26) is provided as web material,

- in which cutouts (29) are introduced into the first supporting film (26) one after the other and at a distance from one another,

- in which the first supporting film (26) provided with cutouts (29) is fed to a processing station (48),

- in which a membrane foil (49) is fed to the processing station (48), which comprises a strip-shaped electrolyte membrane (14) on which catalyst layers (16, 17) are applied in a format on both sides,

- in which the membrane foil (49) is cut into membrane foil blanks (31) in the processing station (48), so that a peripheral edge (32) of the electrolyte membrane (14) is formed to the catalyst layers (16, 17),

- in which the respective membrane film cuts (31) with one of the two catalyst layers (16, 17) are aligned with the respective cutout (29) in the first supporting film (21) and applied to the first supporting film (26),

- in which a second supporting film (27) is provided as web material,

- in which cutouts (29) are introduced into the second supporting film (27) one after the other and at a distance from one another,

- in which the second supporting film (27) is aligned and applied with the respective cutouts (29) to the catalyst layers (17, 16) of the membrane film blanks (31) lying opposite the first supporting film (26) on the first supporting film (26), and

- In which the first and second supporting film (26, 27) and the membrane film blanks (31) arranged between them are firmly connected to one another to form a film composite (35).
Method according to Claim 1, characterized in that the first and/or second supporting film (26, 27) are provided without a carrier layer.
Method according to Claim 1 or 2, characterized in that the first and/or second supporting film (26, 27) is provided with a layer of adhesive applied to one side or is coated on one side with a layer of adhesive in a gluing station (44).
Method according to one of the preceding claims, characterized in that the cutouts (29) are made in succession by punching or laser cutting in the first supporting film (26) before it is fed to the processing station (48).
Method according to one of the preceding claims, characterized in that the successive cutouts (29) are introduced into the second supporting film (27) by punching or laser cutting before it is fed to the membrane film blanks (31) equipped with the first supporting film (26).
Method according to one of the preceding claims, characterized in that in the processing station (48) the membrane foil blanks (31) are cut with a peripheral edge (32) opposite the catalyst layers (16, 17) applied on both sides, so that the peripheral edge (32) opposite all side edges of the catalyst layers (16, 17), which are preferably aligned congruently with the electrolyte membrane (14), has a projection of the same width.
Method according to one of the preceding claims, characterized in that the catalyst layers (16, 17) are applied to the electrolyte membrane (14) in a square or rectangular format and the cutouts (29) in the first and second supporting film (26, 27). the square or rectangular format of the catalyst layers (16, 17) can be adjusted, the size of the cutouts (29) in the first and second supporting foil (26, 27) being cut out to be the same as or smaller than the format of the catalyst layers (16, 17).
Method according to one of the preceding claims, characterized in that the edge (32) of the electrolyte membrane (14) which projects beyond the format of the catalyst layers (16, 17) is bonded to the first and second supporting film (26, 27) in the overlapping region (33). becomes.
Method according to one of the preceding claims, characterized in that a gas diffusion layer (18, 19) is applied simultaneously or successively to each side of the membrane foil cuts (31) of the foil composite (35) produced.
Method according to Claim 9, characterized in that before the gas diffusion layer (18, 19) is applied to the catalyst layers (16, 17) of the membrane foil blank (31), an adhesive layer is applied or that the gas diffusion layer (18, 19) is supplied with an adhesive layer provided thereon becomes.
Method according to Claim 9 or 10, characterized in that the gas diffusion layers (18, 19) are cut to size in a further processing station (74) and applied to the catalyst layers (16, 17) of the film composite (35) and glued.
Method according to one of the preceding claims, characterized in that the membrane foil (49) in the processing station (48) is cut into membrane foil blanks (31) by a pair of vacuum punching rollers with a rotary punching roller (51) and the membrane foil blanks by a vacuum counter-punching roller (52). (31) are successively applied to the first support film (26).
Method according to one of Claims 1 to 11, characterized in that the membrane foil (49) is cut in the processing station (48) by a pair of rotary die-cutting rollers (67, 68) into membrane foil blanks (31) with retaining webs and is connected with a pair of rotary die-cutting rollers (67, 68) subsequently arranged squeezing and laminating roller (69) is applied to the cutouts (29) of the first supporting film (26).
Method according to one of the preceding claims, characterized in that mutually opposite longitudinal edges of the film composite (35) produced are cut to a constant width, preferably by laser cutting.
Method according to one of the preceding claims, characterized in that the film composite (35) is separated into membrane electrode assemblies (25) in a processing station (65), in particular after cutting the film composite (35) to its width, and preferably the Membrane electrode assemblies (25) are separated by cross cutting, preferably by means of laser cutting.
Method according to one of the preceding claims, characterized in that the first supporting film (26), the second supporting film (27) and the membrane film (49) are provided and supplied as semi-finished products on a roll (42, 50, 57).
Method according to one of the preceding claims, characterized in that the application of the membrane film cuts (31) to the first supporting film (26) and the feeding of the second supporting film (27) to the first supporting film (26) are controlled at a continuous web speed.
Membrane electrode assembly for a fuel cell (11),

- with a first and second supporting film (26, 27), each having cutouts (29),

- With a membrane foil blank (31) which comprises an electrolyte membrane (14) as a carrier layer, on both sides of which a catalyst layer (16, 17) is provided, with a peripheral edge (32) of the electrolyte membrane (16, 17) protruding 14) is trained,

characterized,

- that in each case one outer side of the peripherally projecting edge (32) of the membrane foil blank (31) is firmly connected to the side of the supporting foils (26, 27) pointing to the edge (32).
Membrane-electrode assembly according to Claim 18, characterized in that the peripheral edge (32) of the membrane foil blank (31) is glued to the first and second supporting foils (26, 27) in each case in the overlapping region (33).
Membrane-electrode assembly according to Claim 18 or 19, characterized in that the cutout (29) in the first and second supporting film (26, 27) has the same format and is aligned congruently with one another.