WO2019192952A1

WO2019192952A1 - Method for producing a fuel cell with fluid guiding element made from metal fibres and plastic, and a fuel cell

Info

Publication number: WO2019192952A1
Application number: PCT/EP2019/058166
Authority: WO
Inventors: Ulrich Berner
Original assignee: Robert Bosch Gmbh
Priority date: 2018-04-05
Filing date: 2019-04-01
Publication date: 2019-10-10
Also published as: DE102018205128A1

Abstract

The invention relates to a method (100) for producing a fuel cell (1) comprising a fluid guiding element (10) with a textile structure (11) for distributing a fuel (3) to at least one electrode (2) of the fuel cell (1) comprising the following steps: - providing (101) an arrangement of metal fibres (12), - combining (102) plastic elements (13) with the arrangement of metal fibres (12). The invention further relates to a fuel cell (1).

Description

description

title

METHOD FOR PRODUCING A FUEL CELL WITH FLUIDELITE ELEMENT OF METAL FIBERS AND PLASTIC, AND FUEL CELL

The invention relates to a method for producing a fuel cell according to the independent method claim, as well as a fuel cell according to the independent device claim.

State of the art

It is known in the art to provide auxiliaries to one

Distribute fuel as effectively as possible to an electrode. To do this

Usually provided structures which are arranged on the electrode or at least in the vicinity of the electrode and are flown by the fuel.

The structures then ensure that the fuel is distributed over the surface of the electrode and thus an effective use of the fuel is possible. Such structures increase as an additional component, however, on the one hand, the weight of the fuel cell or have, if they z. B. are particularly easily formed, often a low mechanical strength. Furthermore, such structures are usually expensive to manufacture.

Disclosure of the invention

According to the invention, the method for producing a fuel cell or an electrolyzer comprises a fluid guide element having a

Fabric structure for distributing a fuel to at least one electrode of the fuel cell, the following steps:

Providing an arrangement of metallic fibers,

Combining plastic elements with the arrangement of the metallic fibers, Melting and joining the plastic elements with the arrangement of the metallic fibers to the fabric structure,

Mounting the tissue structure in a flow path of the fuel to the electrode.

By the method according to the invention, the above-mentioned disadvantages known from the prior art are at least partially eliminated. Furthermore, the method represents a simple possibility to produce in a cost-effective and simple manner a fuel cell with a fluid guide element, by means of which a fuel can be used efficiently and which at the same time has a high mechanical strength. The mentioned

Process steps are performed in the order mentioned in chronological order, ie step by step. It is also conceivable that tlw. The process steps mentioned can be done simultaneously, such. B. the

Providing an array of metallic fibers occurs simultaneously with combining plastic elements with the array of metallic fibers.

Further features and details of the invention will become apparent from the

Subclaims, the description and the drawings. In this case, features and details that have been described in connection with the method according to the invention, of course, in connection with the fuel cell according to the invention and in each case vice versa, so with respect to the disclosure of the individual aspects of the invention always reciprocal reference is or may be. The invention also includes a method for at least tlw.n production of an electrolyzer and a corresponding electrolyzer.

The joining of the plastic elements with the arrangement of the metallic fibers to the fabric structure may preferably be positive and / or cohesive. In particular, the fuel cell may be a polymer electrolyte membrane (PEM) fuel cell. The electrode may in particular comprise an anode and / or a cathode of the fuel cell. The fuel may in particular comprise hydrogen and / or oxygen. The flow path of the fuel may preferably be a flow channel include, through which the fuel from a fuel inlet to the electrode is feasible. By mounting the Fluidleitelementes in

Flow path, the fluid guide element thus flows against the fuel and can be distributed efficiently at the electrode. The fluid guide element has the

Tissue structure comprising metallic fibers and plastic elements. By melting the plastic elements, a fastening of the plastic elements with the metallic fibers can be ensured in a simple manner. During the melting, the plastic elements are preferably initially thermally mixed in an at least partially liquid and / or viscous state, so that the plastic elements enclose the metallic fibers at least partially. The bonding to the fabric structure comprises, in particular, curing of the molten plastic elements. The metallic fibers may be electrically conductive. Furthermore, the plastic elements may be non-conductive or conductive. To realize a conductivity, the plastic elements conductive

Have polymers and / or conductive particles. The metallic fibers may in particular comprise metallic textile threads, wires or other textile elements. Under the arrangement of the metallic fibers may further include

Raw fabric can be understood. Preferably, providing the arrangement of the metallic fibers comprises weaving the metallic fibers together. As a result, the arrangement of the metallic fibers z. B. when combined with the plastic elements are handled as a unit. Due to the fabric structure, the fluid guide element has a low weight. Furthermore, the fabric structure is preferably at least partially permeable to

Reaction gases and / or liquids. By the combination of

Plastic elements and metallic fibers can further advantageous properties of both types of material are combined.

In the context of the invention, it is also conceivable that the method comprises the following step:

Deforming the fabric structure or the arrangement of the metallic

Fibers to a wavy shape.

Preferably, the wave-like shape may comprise a sinusoidal shape. Furthermore, it is conceivable that the wave-like form comprises folds, which For example, can be fixed when melting the plastic elements.

In particular, the deformation may be performed prior to combining the plastic elements with the metallic fibers, so that only the

Arrangement of the metallic fibers undergoes the shaping or the

Fabric structure can be deformed when the plastic elements are already combined with the metallic fibers and / or melted. By deforming the fabric structure or the arrangement of the metallic fibers into a wave-like shape, a geometry of the fluid-conducting element can thus be produced in a simple manner, which has an advantageous effect on the distribution of the fuel at the electrode or on the flow properties of the fluid-conducting element. In particular, sub-channels can be created by the wave-like shape along which the fuel can flow and be distributed. In particular, it may be provided that material contracts during the deformation, so that changes in length due to the deformation within the fabric structure can be compensated for, without any elastic and / or plastic strain being introduced into the material.

Furthermore, it can be provided in a method according to the invention that the melting of the plastic elements and the deformation of the fabric structure are performed simultaneously. For example, it is conceivable that the deformation is carried out by a shaping roller. This can be the

Forming roll have a toothing, which impresses the wave-like shape in the fabric structure. In order to ensure the same time the melting of the plastic elements, can also be provided that the shaping roller tempered, in particular heated, is. Preferably, two counter-rotating forming rollers can perform the deformation of the tissue structure. Thus, the time required to perform the process can be reduced if the melting and the deformation are performed simultaneously. Furthermore, it may be advantageous if the forming roller combines different measures, so that, for example, a need for production space for the production of the fuel cell can be reduced. Preferably, in a method according to the invention, it may further be provided that the combination of the plastic elements with the fabric structure comprises a loose application of the plastic elements to the metallic fibers or a weaving of the plastic elements with the metallic fibers. The loose application can, for example, a scattering of the plastic elements on the

Arrangement of the metallic fibers include. Thus, an attachment of the plastic elements, for example. Only be made with the melting or plastic elements can be previously woven into the arrangement of metallic fibers. The loose application has the advantage that the plastic elements, for example. Short plastic fibers and / or a

Plastic powder and can be automated in a simple manner and in particular portioned applied to the arrangement of metallic fibers. The interweaving of the plastic elements with the metallic fibers, in which the plastic elements may preferably have plastic threads or plastic strips, offers the advantage that the metallic arrangement and the plastic elements can be handled as a unit, so that further processing steps can be simplified.

In the context of the invention, it may further be provided that the melting of the plastic elements comprises at least one of the following steps:

Tempering a shaping roller,

Flow at least partially plastic elements at least partially with a tempered gas,

Irradiating at least the plastic elements at least partially with a laser.

The tempering of the forming roll and / or the gas can

Preferably, a heating of the shaping roller or of the gas, in particular to a melting temperature of the plastic elements comprise. As a result, the plastic elements can be heated over a large area, so that it can be ensured as required that all plastic elements are melted. By irradiating the plastic elements with a laser, an optical method can be provided which can have high reliability during melting and / or specifically determined Bring areas of plastic elements to melt. Additionally or alternatively, the temperature control by infrared light, for example. By a radiant heater, take place.

It is also conceivable in the case of a method according to the invention that following the melting of the plastic elements, in particular after the curing of the plastic elements and / or after the deformation of the fabric structure, the following step is carried out:

Removal of unwanted plastic residues.

For example. If the plastic elements are merely loosely applied to the arrangement of the metallic fibers, it may occur that individual fibers are not melted and thus do not permanently bond to the metallic fibers. Therefore, it may be advantageous to such

Remove plastic residues. Removing unwanted

Plastic residues may also include a mechanical reworking, in particular a deburring, if, for example. When melting and subsequent curing of the plastic elements burr remains.

It may further be provided in a method according to the invention that the plastic elements are present in combination with the arrangement of the metallic fibers as a single plastic fibers, as a fiber layer and / or as a flat plastic tape. For example, the plastic elements may be isolated as plastic fibers and counted or portioned by weight. However, it may be advantageous to use the plastic elements as a preformed unit as a fibrous layer or as a flat plastic strip

contribute. As a result, the plastic elements can be handled in a simple manner. Furthermore, this can be formed a planar connection of the plastic elements with the metallic fibers. As a result, the mechanical strength of the fluid guide element and thus the service life of the fuel cell can be improved.

Preferably, in a method according to the invention, the plastic elements may comprise a thermoplastic and / or the plastic elements (13) may be electrically conductive. Especially For example, the plastic elements may be a polyethylene terephthalate (PET)

Polypropylene (PP) Polyethylene (PE), polystyrene (PS) or a

Polytetrafluoroethylene (PTFE) have. The plastic itself may be electrically conductive and / or contain electrically conductive particles, such as, for example, graphite and / or nanotubes. Preferably, the thermoplastic material has a high thermal processability, so that the melting of the

Plastic elements requires only a small amount of energy and / or can be reliably reproduced. In particular, the

Plastic elements at least partially hydrophobic and / or hydrophilic. As a result, the properties of the fluid guide element with respect to the fuel can be improved, in particular if the fuel has oxygen or hydrogen. Thus, the fluid guide by the

melted plastic elements, a water content of the fuel at the electrode to be influenced.

In the context of the invention, the plastic elements can be advantageously melted in the region of constrictions. Thus, a mechanical strength, in particular with regard to the shape of the

Fluidleitelementes be improved. The constrictions preferably form undercuts of the fabric structure such that channels are formed having improved fuel guiding properties. Furthermore, the fluid guide element can be handled and assembled in a simplified manner by improved dimensional stability.

According to a further aspect of the invention, a fuel cell is claimed with a fluid guide. The fluid guide is in one

Flow path of a fuel for distributing the fuel to at least one electrode of the fuel cell is arranged. Furthermore, the

Fluidleitelement a fabric structure with metallic fibers and

Plastic elements on. The plastic elements are connected by melting, and in particular curing, with the arrangement of the metallic fibers. The fuel cell is preferably produced by a method according to the invention. Thus, a fuel cell according to the invention brings the same advantages as have already been described in detail with reference to a method according to the invention. In particular, the Fuel cell easy to manufacture and has a long service life with efficient fuel use.

Further, measures improving the invention will become apparent from the following description of some embodiments of the invention, which are shown schematically in the figures. All from the

Claims, the description or the drawings resulting features and / or benefits, including constructive details, spatial

Arrangements and method steps can be essential to the invention, both individually and in the most diverse combinations. It should be noted that the figures have only descriptive character and are not intended to limit the invention in any way. Show it:

1 is a schematic representation of method steps of a method according to the invention in a first embodiment,

Fig. 2a-c Advantageous Aufschmelzmöglichkeiten of plastic elements according to further embodiments.

3a-d fabric structures according to further embodiments in a schematic representation,

4 shows a fuel cell according to the invention in a schematic

Representation in a further embodiment,

Thus, a method according to the invention entails the same advantages as have been described in detail with reference to a device according to the invention.

1 shows a method 100 according to the invention for producing a fuel cell 1 in a schematic representation of method steps 101 to 107 in a first exemplary embodiment. The fuel cell 1 to be produced in this case has a fluid guide element 10 with a fabric structure 11 in order to

Fuel 3 to at least one electrode 2 of the fuel cell 1 advantageous to to distribute. The method 100 in this case comprises providing 101 a

Arrangement of metallic fibers 12. In particular, the metallic fibers

12 interwoven with each other for arrangement and form a manageable unit. Subsequently, a combination 102 of plastic elements 13 takes place with the arrangement of the metallic fibers 12. Combining the plastic elements

13 with the arrangement of the metallic fibers 12, a loose application 102.1, for example, by sprinkling the arrangement of the metallic fibers 12 with the plastic elements 13, and / or a weaving 102.2 of

Plastic elements 13 with the metallic fibers 12 include. The weaving 102.2 can, for example, also be carried out parallel to the provision 101 of the arrangement of the metallic fibers 12, wherein the plastic elements 13 are already woven together with the metallic fibers 12 during the production of the arrangement. To a positive and / or cohesive

To achieve connection of the metallic fibers 12 with the plastic elements 13 is further a reflow 103 and a curing 104 of the

Plastic elements 13 are provided. This provides the fabric structure 11 with improved mechanical strength. Furthermore, a can also

Transition resistance may be reduced if the plastic elements 13 are electrically conductive, in particular have an electrically conductive polymer and / or electrically conductive particles. For this purpose, the plastic elements 13th

preferably a thermoplastic material which has good thermal processability. In particular, it is also conceivable that the arrangement of the metallic fibers 12 only by the melting 103 and curing 104 of the plastic elements 13 into a single

manageable unit is formed. Furthermore, the method 100 comprises deforming 105 the fabric structure 11 or the arrangement of the metallic fibers 12 into a wave-like shape. By the wave-like shape channels of the fabric structure 11 are impressed, through which the fuel 3 is advantageously conductive. If, for example, unfused plastic residues are present or a burr has formed during melting 103, a removal 106 of the plastic residues may also be provided in order to improve the flow of the fuel 3. Subsequently, when mounting 107 of the fluid guide element 10, the tissue structure 11 can be arranged in a flow path 4 of the fuel 3 to form an electrode 2. FIGS. 2 a to 2 c show advantageous melting possibilities of a fabric structure 11 of a fluid guide element 10 in further exemplary embodiments. According to FIG. 2 a, a wave-like shape of a fabric structure 11 is impressed by two counter-rotating shaping rollers 20. In this case, a tempering 103.1 is further provided at least one of the forming rollers 20 to cause a melting 103 of plastic elements 13 so that they harden after passing through the shaping rollers 20 and form and / or materially connect with metallic fibers 12 of the fabric structure 11. Thus, the reflow 103 and the deformation 105 are simultaneously executable. FIG. 2b also shows a flow 103.2 of the plastic elements 13 and the metallic fibers 12 of the fabric structure 10 with a tempered gas 30, so that the plastic elements 13 melt. Additionally or alternatively, the melting 103 may comprise irradiating 103.3 of the plastic elements 13 with a laser 40 according to FIG. 2 c so that certain areas are locally heated and melted. It is also conceivable that the tempering 103.1 of the shaping roller 20, the flowing 103.2 of the plastic elements 13 with a tempered gas 30 and the irradiation 103.3 of the plastic elements 13 with a laser 40 or an infrared emitter (not shown) combined or performed sequentially to allow a more reliable melting 103 or to process individual areas individually.

FIGS. 3a to 3d also show fluid guide elements 10 with tissue structures 11 in wave-like shapes in further exemplary embodiments in a schematic representation. In this case, the fabric structures 11 comprise both metallic fibers 12, as well as plastic elements 13. The plastic elements 13 may preferably along the longitudinal and / or transverse direction of the

Fabric structure 11 extend. In particular, the plastic elements 13 may be parallel, i. e.g. along wavefronts, or perpendicular, i. e.g. orthogonal to the wave flanks, to the wave-like shape. According to FIG. 3 a, the plastic elements 13 have individual plastic fibers 13. 1. As a result, for example, a loose application 102.1 of the individual plastic fibers 13.1, in particular by sprinkling an arrangement of the metallic fibers 12, possible. In the embodiment of Figure 3b, the plastic elements comprise a

Fiber layer 13.2, which, for example. As a plastic fleece on the metallic fibers 12 can be launched. According to FIG. 3c, the plastic elements 13 comprise plastic bands 13.3. The plastic strips 13.3 can have a wide extension, in particular in the transverse and / or longitudinal direction, so that a single plastic strip 13.3 can cover a region of the fabric structure 11. Additionally or alternatively, the plastic straps 13.3 may be thread-like and, for example, be woven with the metallic fibers 12 and / or be sinusoidal. FIG. 3d furthermore shows a cross section of a fabric structure 11 in a further exemplary embodiment. There are

Plastic elements 13 arranged in the region of constrictions 14 and fused with metallic fibers 12. As a result, the constrictions can be stabilized and thus the entire mechanical strength of the

Fabric structure 11.

FIG. 4 also shows a fuel cell 1 with two electrodes 2, one of the electrodes 2 serving as anode and the other electrode 2 as cathode of FIG

Fuel cell 1 is formed. Further, the electrodes 2 with

Fuels 3 flows. Preferably, one of the fuels has 3 oxygen and the other hydrogen. In the flow paths 4 of the fuels 3, a fluid guide element 10 is further arranged in each case with a fabric structure 11 in order to distribute the respective fuel 3 over a surface of the electrodes 2. The fabric structures 11 in this case have plastic elements 13, which are fused with metallic Faseril. As a result, an efficiency of the fuel cell 1 can be increased, since the fuels 3 can react better with one another due to the fluid guide element 10 and at the same time the tissue structure 11 has a high mechanical strength so that a high service life of the tissue structure 11 is achieved even with dynamic pressures within the flow paths 4 can.

The above explanation of the embodiments describes the present invention solely by way of example.

Of course, individual features of the embodiments, if technically feasible, can be combined freely with one another, without departing from the scope of the present invention.

Claims

claims

A method (100) for producing a fuel cell (1) comprising a fluid guide element (10) having a tissue structure (11) for distributing a fuel (3) to at least one electrode (2) of the fuel cell (1), comprising the following steps:

Providing (101) an arrangement of metallic fibers (12), combining (102) plastic elements (13) with the arrangement of the metallic fibers (12),

Melting (103) and joining the plastic elements (13) with the arrangement of the metallic fibers (12) to the fabric structure (10),

Mounting (107) the fabric structure (11) in a flow path (4) of the fuel (3) to the electrode (2).

2. Method (100) according to claim 1,

characterized,

the method (100) comprises the following step:

Deforming (105) the fabric structure (11) or the arrangement of the metallic fibers (12) into a wave-like shape.

3. Method (100) according to claim 2,

characterized,

that the melting (103) of the plastic elements (13) and the

Deforming (105) of the fabric structure (11) are carried out simultaneously.

4. Method (100) according to one of the preceding claims,

characterized,

in that combining the plastic elements (13) with the fabric structure (11) loosely applies (102.1) the plastic elements (13) to the arrangement of the metallic fibers (12) or interweaves (102.2) the plastic elements (13) with the metallic fibers (12). 12).

5. Method (100) according to one of the preceding claims,

characterized,

in that the melting (103) of the plastic elements (13) comprises at least one of the following steps:

Tempering (103.1) a shaping roller (20),

Flow (103.2) at least the plastic elements (13) at least partially with a tempered gas (30), irradiating (103.3) at least the plastic elements (13) at least partially with a laser (40).

6. Method (100) according to one of the preceding claims,

characterized,

in that the following step is carried out after melting (103) of the plastic elements (13):

Remove (106) unwanted plastic residues.

7. Method (100) according to one of the preceding claims,

characterized,

that the plastic elements (13) when combining (102) with the

Arrangement (12) of the metallic fibers as a single plastic fibers (13.1), as a fibrous layer (13.2) and / or as a flat plastic strip (13.3) are present.

8. Method (100) according to one of the preceding claims,

characterized,

in that the plastic elements (13) have a thermoplastic and / or that the plastic elements (13) are designed to be electrically conductive.

9. Method (100) according to one of the preceding claims,

characterized,

that the plastic elements (13) in the region of constrictions (14) of the

Arrangement of the metallic fibers (12) are melted.

10. Fuel cell (1), in particular produced by a method (100) according to one of the preceding claims, with a fluid guide element (10) which in a flow path (4) of a fuel (3) for

Distribution of the fuel (3) to at least one electrode (2) of the fuel cell (1) is arranged, wherein the Fluidleitelement (10) has a fabric structure (11) with an arrangement of metallic fibers (12) and plastic elements (13), wherein the plastic elements (13) are connected by melting (103) with the arrangement of the metallic fibers (12).