DE102005058370A1 - Fuel cell and roll-to-roll process to manufacture fuel cell assembly with electrical membrane units ultrasonically welded to surrounding frame - Google Patents

Abstract

A fuel cell has two or more bi-polar plates, an electrode membrane unit. A gas diffusion layer separates each electrode membrane unit from the plate. In a process to manufacture a fuel cell of this type, the electrode membrane units and the supporting frames are brought together in a roll-to-roll assembly process and joined by ultrasonic welding action. The ultrasonic energy is directed at the frame. In an alternative embodiment, individual membrane units and frames are brought together in synchronized cycles. Further claimed is a commensurate fuel cell.

Description

TECHNICAL AREA

The The invention relates to a fuel cell and a method for the production Such a fuel cell and an apparatus for carrying out a such method of manufacturing a fuel cell.

The Fuel cell technology is an environmentally friendly technology by the use of hydrogen and oxygen and thus of non-fossil fuels. As a further advantage turns out to be the opposite conventional internal combustion engines much higher efficiency.

WAS STANDING OF THE TECHNIQUE

Such a fuel cell is known. In addition, it is from the DE 42 06 490 C2 and the art mentioned therein, to use various structures to distribute the gases over the entire cross-sectional area of the fuel cell. Furthermore, it is from the DE 26 35 636 C2 known to use in the manufacture of fuel cells so-called roll-to-roll method in connection with the production of both sides with gas diffusion layers electrode material. In this manufacturing process, which uses reel goods, the individual layers are glued together. The removal of the webs from the respective roll can be continuous or discontinuous.

Otherwise The fuel cell is formed by superimposing the various plate-shaped layers one by one made of such a cell.

PRESENTATION THE INVENTION

outgoing From this prior art, the invention is based on the object produced as inexpensively as possible To provide fuel cells.

These Invention is for the fuel cell according to the invention by the claim 1, for the inventive method for producing such a fuel cell by the features of claim 7 and for a device according to the invention, to the execution This manufacturing method is particularly suitable, by the features of claim 16 given. Useful developments of the invention are given by the features of each subsequent claims.

The Fuel cell according to the invention records characterized by at least that between two bipolar plates existing cell component in the so-called roll-to-roll method can be produced. By the ultrasonic welding process used for adhering the Electrode Membrane Unit (EME) to a support frame let yourself on the one hand, the respective EME in this roll-to-roll process without problems deploy. In this case, by means of the ultrasonic welding process a gastight, technically fully functional connection between the EME and the carrier frame getting produced.

Of the support frame can consist of two frame parts. Each of these frame parts can at Producing the fuel cell also unwound from a roll to disposal be put. In the carrier frame or in the two frame parts are openings in the manner of window openings cut or punched out, which then closed again by the EME become. The EME and the carrier frame or the two frame parts are then with a circumferential ultrasonic welding gas-tight welded together. Subsequently is attached to such a web layer, which is the inner part of a fuel cell represents, applied on both sides of a gas diffusion layer (GDL). each of these gas diffusion layers is also available as roll stock. The individual GDL cutouts are separated from the roll goods and then attached to the EME. The procedure remains between the circumferential edge of the GDL and the support frame a gap, whereby the electrical power of this fuel cell but only slightly is reduced. Attaching this GDL to the EME can also be done via a Ultrasonic welding or over one Bonded connection can be made. Then then such a between each two bipolar plates existing cell constituent stored and thus in stock being held. It is also possible, to attach this cell component to at least one bipolar plate and then in stock in this form to keep.

alternative it is also possible the GDL not at the EME but only at the respective bipolar plate to fix. This attachment can also be via an ultrasonic weld or be effected by an adhesive bond.

Further Embodiments and advantages of the invention are those further in the claims listed Characteristics and the embodiments illustrated in the drawing refer to.

SHORT DESCRIPTION OF THE DRAWING

The invention is described below with reference to the embodiments illustrated in the drawings described and explained in detail. Show it:

1 a layer structure of a cell unit of a fuel cell,

2 A second embodiment of a cell unit of a fuel cell,

3 a schematic process flow for producing the cell unit of a fuel cell according to 1 .

4 a perspective schematic representation of the different sheet layers of the cell unit according to the layer structure of 1 , before their final mutual connection,

5 a cut in the direction of the arrow 5 of the 4 .

6 a cut in the direction of the arrow 6 of the 4 .

7 a representation similar to that of 4 for a layer construction according to 2 .

8th a cut in the direction of the arrow 8th of the 7 .

9 a cut in the direction of the arrow 9 of the 7 .

10 a plan view of a layer structure according to 1 .

11 a plan view of a layer structure according to 2 .

12 a top view of an existing in the manufacturing process ultrasonic welding station,

13 a cut in the direction of the arrow 13 of the 12 .

14 a cut in the direction of the arrow 14 of the 12 .

15 a cut in the direction of the arrow 15 of the 12 ,

WAYS TO EXECUTE INVENTION

In 1 is the layer structure of an inner cell unit 12 shown consisting of an internal electrode membrane unit (EME) 15 that exists between two support frames 14 . 16 is arranged. On both outer sides of the inner cell unit 12 becomes a gas diffusion layer (GDL) 18 . 20 arranged. On the two outer sides of this GDL 18 . 20 is then a bipolar plate 22 . 24 arranged. The structured bipolar plates 22 . 24 with the cell layers existing between them form a fuselage cell 26 , A corresponding fuel cell could have one or more inner cell units 12 , each bipolar plates 22 . 24 and intervening GDL 18 . 20 could contain included. Outside the outer bipolar plates 22 . 24 then pantograph plates and, for example, end abutment plates would be available. The abutment plates, pantograph plates, bipolar plates and the inner cell unit 12 with their two support frames 14 . 16 could then be joined together by, for example, in their corner frame passing through mounting rods or threaded rods to a solid fuel cell. Such a stacked construction of fuel cells is known per se.

In the present example, the in 1 illustrated inner cell unit 12 two support frames 14 . 16 available. The two support frames 14 . 16 are identical. In each one of them is a central window opening 30 . 32 available. The EME 15 lies on the sides facing this support frame 14 . 16 and covers the window opening 30 . 32 Completely. In production direction 34 hereafter referred to in connection with 3 and the following is explained in more detail, which has between the two support frames 14 . 16 positioned EME 15 a length 36 , which is the same size as the length 38 the two support frames 14 . 16 , This is the one in production direction 34 front edge 40 the EME 15 in alignment with the front edge 42 the two support frames 14 . 16 , The same applies to the rear edge 46 the EME 15 , which with the rear edges 48 the two support frames 14 . 16 flees. In the transverse direction 50 is the width 52 the EME 15 smaller than the width 54 the two support frames 14 . 16 but bigger than the width 56 the two window openings 30 . 32 , The thereby forming coverage area 58 is on the support frame 16 hatched hinted. On the in 1 rear support frame 14 is a comparable coverage area between the carrier frame 14 and the EME 15 available.

When attaching the EME to each other 15 on the two support frames 14 . 16 becomes one in the frame-like coverage area 58 circumferential ultrasonic weld produced. This ultrasonic weld can be used throughout the coverage area 58 the two support frames 14 . 16 to be available. The ultrasonic weld can also only in one opposite the width of the overlap area 58 be formed narrower, circumferential frame seam. Importantly, the EME 15 gas and liquid tight on the two support frames 14 . 16 is attached.

From the outside on the inner cell unit 12 will then be in the area of the window openings 32 of each support frame 14 . 16 a GDL 18 respectively 20 created and at the EME 15 in the area of the window opening 32 fixed in position fixed. As will be described in more detail below, this positional fixation is also feasible by means of an ultrasonic welding or via a bond.

In the 2 illustrated inner cell unit 12.2 is different from the inner cell unit 12 in that the front edge 40.2 the EME 15.2 inside the two support frames 14 . 16 is present and not with the respective front edge 42 of these two carrier frames 14 . 16 flees. The same applies to the rear edge 46.2 the EME 15.2 , The EME 15.2 surrounds the window opening 30 . 32 with a narrower frame than the EME 15 ( 1 ) the case is. This frame covering area 58.2 is just the production direction 34 narrower available; in the other direction 50 can the frame at the EME 15.2 be the same width as the EME 15 ,

At the in 3 illustrated manufacturing method of the inner cell unit 12 becomes the EME 15 as a train 15a from a web roll 60 settled. On the web roll 60 is the EME 15 with a protective film 62 provided so that wound EME webs 15a do not have direct contact with each other. This protective film 62 is after a small distance over a pulley 64 away to - in 3 - pulled down and on a take-up roll 66 wound up and removed from the production process. The EME train 15a will then be in production direction 34 between two roles 68 . 70 passed.

In addition, between the two roles 68 . 70 from above a carrier web 72 and from below a carrier web 74 passed from the top or bottom of the EME train 15a issue. These two carrier webs 72 . 74 are made of plastic and are made of a web roll 76 . 78 deducted. Before these peeled carrier webs 72 . 74 , in the area of the two roles 68 . 70 arrive are in a cutting-punching device 80 . 82 the window openings 30 . 32 in the relevant carrier web 72 . 74 made by corresponding web areas from the respective carrier web 72 . 74 be cut out.

After passing through the range of rollers 68 . 70 comes the three-layer cell unit 12 , in which the individual layers are still loose on one another, in the area of a first ultrasonic welding station 86 , In this station 86 is in the range of coverage areas 58 the two carrier webs 72 . 74 a circumferential gas and liquid-tight ultrasonic welding connection between the two outer carrier webs 72 . 74 and the intervening EME train 15a produced. As the 4 . 5 and 6 show, the individual EME sections hang 15 endlessly together. After a later cutting through the still contiguous inner cell units 12 through a separation cut 88 between two window openings 30 or two window openings 32 runs, then can single inner cell units 12 be generated.

This cutting along the separating cut 88 does not take place in the 4 state, but only when the individual GDL 18 or 20 inserted into the window openings and there at the respective EME 15 are.

From the 5 and 6 it becomes clear that in production direction 34 the individual EME 15 are just as long as the individual support frames 14 . 16 an inner cell unit 12 , In the transverse direction 50 ( 5 ) is the extent of an EME 15 smaller than the two support frames 14 . 16 ,

Each of the two GDL 18 . 20 is smaller in area than the one through the window openings 30 . 32 framed surface area or area detail. This is between the circumferential edge 90 the GDL and the window opening 30 respectively 32 a circumferential, small gap 92 available.

The presentation of the 7 . 8th and 9 refers to the inner cell unit 12.2 of the 2 , The EME sections 15.2 the train 15a are individually as the size of the cell unit 12.2 adapted sections between the two carrier webs 72 . 74 Positioned and then connected by an ultrasonic welding with the two carrier webs, as related to 2 already described. The EME 15.2 are therefore smaller in each dimension direction than the corresponding extensions of the two window openings of a cell unit 12.2 , Also this EME 15.2 can be made available as a web roll, only the individual EME sections are still to be made by cutting off the corresponding web before assembling with the two support frame.

10 shows a plan view of a cell unit 12 and 11 a plan view of the cell unit 12.2 , The respective coverage area 58 respectively 58.2 shows that at the cell unit 12 immediately the EME 15 in the form of a continuous web 15a between the two support frames 14 . 16 can be positioned. At the cell unit 12.2 are only sections of the corresponding EME train 15a make before this Sections then as EME 15.2 between the two support frames 14 . 16 can be positioned.

The sectionwise and, as it were, portionwise positioning of individual GDLs 18 respectively 20 on the two support frames 14 . 16 can be made by technologies known per se in the art. So can a GDL 18 . 20 only from a web roll 100 respectively 102 be deducted as a train. Subsequently, the respective web is in a cutting-punching device 104 . 105 divided into sections. These individual sections are from a transfer device 106 . 107 individually sucked, by accelerating the executed as a roller transfer device 106 . 107 then correctly positioned on the upper carrier web 72 or lower carrier web 74 created, as in 7 is shown by way of example.

In a subsequent second ultrasonic welding station 110 become the two GDL 18 . 20 in the area of the respective window opening 30 . 32 the two carrier webs 72 . 74 to the respective EME 15 attached to.

In this second ultrasonic welding station 110 lies from above and below at the two carrier webs 72 respectively 74 an endlessly circulating upper conveyor belt 112 or a lower conveyor belt 114 at. Through these two bands 112 . 114 become the individual GDL at the carrier webs 72 . 74 held. These two conveyor belts 112 . 114 do not completely cover the GDL, in the present case are - based on 12 - an upper edge area 116 and a lower edge area 118 , each at the lower GDL 18 and upper GDL 20 not from the two conveyor belts 112 . 114 covered. In the upper edge area 116 is a sonotrode in the left corner 120 arranged. Just below that is the lower GDL 18 an anvil 122 , In the upper right corner are a sonotrode 120 and an anvil 122 arranged opposite, like 12 clarified.

In the lower edge area 118 are an anvil in the upper left corner 122 and below a sonotrode 120 arranged. In the lower right corner there is a sonotrode on the top 120 and below an anvil 122 available. Two sonotrodes 120 act in two opposite corners of the GDL 18 . 20 on the layer package in the second ultrasonic welding station 110 one. Corresponding four ultrasonic welding joints 126 are then available throughout the four corners.

The sonotrodes 120 and the anvils interacting with them 122 can in production direction 34 be moved when making the ultrasonic welding connections. If the web layers at least in the region of the second ultrasonic welding station 110 clocked be transported, the sonotrodes 120 and anvils 122 be arranged stationary.

Subsequently, in a singling station 130 ( 3 ) the individual cell units 12 respectively 12.2 made by attaching the in 4 indicated separating cuts 88 ,

Subsequently, then the cell units 12 . 12.2 in another station 132 with, for example, a bipolar plate 22 or 24 positionally sufficiently tightly joined together and then be kept in stock, for example, stacked, to then be installed in correspondingly large, any number of unit cells containing fuel cells.

The thickness of a GDL 18 . 20 is about the same thickness or slightly thinner than a support frame 14 respectively 16 ,

Claims (20)

Fuel cell - with at least two bipolar plates ( 22 . 24 ), - with an electrode membrane unit (EME) ( 15 . 15.2 ) between the bipolar plates, - each with a gas diffusion layer (GDL) ( 18 . 20 ) between a bipolar plate ( 22 . 24 ) and the EME ( 15 . 15.2 ), - characterized in that - the EME ( 15 . 15.2 ) on a support frame ( 14 . 16 ), - between the EME ( 15 . 15.2 ) and the support frame an ultrasonic welding connection is present, - this ultrasonic welding connection one on the EME ( 15 . 15.2 ) is formed as a circumferential frame weld. Fuel cell according to claim 1, - characterized in that - the support frame ( 14 . 16 ) of two flat superimposed, in each case at least one window opening ( 30 . 32 ) comprises the frame parts, - the weld seam as a frame in which the window opening ( 30 . 32 ) each surrounding coverage area ( 58 . 58.2 ) is trained. Fuel cell according to claim 2, characterized in that - the EME ( 15 ) in at least one dimension direction a length ( 36 ), which is the same size as the length (38) of a support frame ( 14 . 16 ) in this direction ( 34 ). Fuel cell according to one of the preceding Claims, - characterized in that - the thickness of a GDL ( 18 . 20 ) is approximately the same thickness as a frame part ( 14 . 16 ) or slightly thinner than a frame part ( 14 . 16 ). Fuel cell according to one of the preceding claims, - characterized in that - between the window reveal of a window opening ( 30 . 32 ) and the edge ( 90 ) of a GDL ( 18 . 20 ) a circumferential gap ( 92 ) is available. Fuel cell according to one of the preceding claims, characterized in that - an ultrasonic welding connection or an adhesive connection between at least one bipolar plate ( 22 . 24 ) and a frame part ( 14 . 16 ) is available. Method for producing a fuel cell after one of the preceding claims, wherein between at least two bipolar plates an EME and between this EME and every bipolar plate a GDL is present - thereby marked that - the EME and the carrier frame each merged as individual roller conveyors continuously or clocked and by ultrasonic welding be attached to each other, wherein - the ultrasound generated Welded joint in one around a window opening in the carrier frame running around portion of the support frame is present. Method according to claim 7, - characterized in that - from an EME railway and the carrier railway existing and to be fastened to each other railway layers as well the two GDL orbits merged continuously or clocked and be attached to each other. Method according to claim 7 or 8, - thereby marked that - of the support frame is composed of two frame parts, - each Frame part is present as a single roller conveyor, - the EME arranged between the two frame parts and attached to the same becomes. Method according to claim 9, - characterized in that - each of the both GDL in an ultrasonic welding process to each one Side of the EME fixed in position. Method according to claim 10, - thereby marked that - by Both GDLs pass through one GDL to EME one after the other subsequently the other GDL is welded to the EME. Method according to claim 10, - thereby marked that - by both GDLs are welded to both GDLs simultaneously to the EME. Method according to claim 11 or 12, - thereby marked that - in a first area of the EME the one GDL and in a second area EME the other GDL is welded to the EME. Method according to claim 7, - characterized in that - at least a bipolar plate is attached to a GDL fixed in position. Method according to claim 14, - thereby marked that - one GDL to a bipolar plate in an ultrasonic welding process fixed in position. Device for carrying out the method for producing a fuel cell, according to one of Claims 7 to 15, characterized by a first ultrasonic welding station ( 86 ), - a first feed unit for feeding a first and a second carrier web ( 72 . 74 ) and an EME train ( 15a ) in the first ultrasonic welding station ( 86 ), wherein in the first ultrasonic welding station ( 86 ) the EME train ( 15a ) between the two carrier webs ( 72 . 74 ), - a subsequent second feed unit for feeding in each case individual GDL ( 18 . 20 ) on the one and on the other flat side of the output side of the first ultrasonic welding station ( 86 ), by GDL ( 18 . 20 ) doubled web layers, - a subsequent second ultrasonic welding station ( 110 ) for the positionally fixed attachment of the two GDLs ( 18 . 20 ) to the exposed area of the EME. Apparatus according to claim 16, characterized in that - a cutting-punching device ( 80 . 82 ) for producing window openings ( 30 . 32 ) in the carrier webs ( 72 . 74 ) is available. Device according to claim 16, - characterized in that - at least the welding electrodes ( 120 . 122 ) of the first and / or the second ultrasonic welding station ( 86 . 110 ) in the conveying direction ( 34 ) of the web are movable with the same. Device according to one of claims 16 to 18, - characterized in that - in the first and second ultrasonic welding stations ( 86 . 110 ) at least one sonotrode ( 120 ) on one side of the web and at least one anvil ( 122 ) is present on the other side of the track. Device according to claim 19, - characterized in that - in the first and / or second ultrasonic welding station ( 86 . 110 ) in each case at least one sonotrode ( 120 ) is present on both sides of the track, - each on one side of the track existing sonotrode ( 120 ) with an anvil on the other side of the track ( 122 ) is effectively arranged together.