WO1997001194A1

WO1997001194A1 - Electrochemical solid electrolyte cell system

Info

Publication number: WO1997001194A1
Application number: PCT/DE1996/001123
Authority: WO
Inventors: Konstantin Ledjeff; Roland Nolte
Original assignee: Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.
Priority date: 1995-06-21
Filing date: 1996-06-21
Publication date: 1997-01-09
Also published as: DE19624887A1

Abstract

An electrochemical solid electrolyte cell system consists of a flat, gas-permeable, non-conductive substrate (1). The first porous, electroconductive electrode layer (7), the proton-conductive membrane layer (8) and the second porous, electron-conductive electrode layer (11) of at least one cell area (3) are superimposed according to the thin-film technique on one surface (2) of the substrate (1).

Description

Electrochemical solid electrolyte cell system

The invention relates to an electrochemical solid electrolyte cell system in which a first porous, electrically conductive electrode layer, a proton-conducting membrane layer and a second porous, electronically conductive electrode layer are applied to a surface of a gas-permeable support body by means of layer technology.

Electrochemical cells are known, for example, in the form of the fuel cell or the electrolysis cell. Fuel cells, for example, convert chemical energy directly into electrical energy with high efficiencies (50-60%). They simply consist of two electrodes and an electrolyte in between. The chemical energy carriers are continuously introduced to the electrodes and converted electrochemically. As a typical example Hydrogen-oxygen fuel cell called, where one electrode is supplied with hydrogen and the other electrode with oxygen. The following electrochemical reactions then take place voluntarily on the catalytically active electrodes.

Hydrogen electrode (anode): H ₂ -> 2 H ⁺ + 2 e ^" Oxygen electrode (cathode): 0.50 ₂ + 2 H ⁺ + 2 e ^" -> H ₂ 0.

There is a proton-conducting electrolyte between the two electrodes, which in the case of a PEM fuel cell (polymer electrolyte membrane fuel cell) is a proton-conductive polymer membrane. A voltage can then be tapped at the two electrodes, which typically ranges between 0.5 and 1 V, depending on the electrical load.

In order to realize higher output voltage for practical applications, the so-called bipolar

Stacked construction a large number of cells connected in series by means of electronically conductive bipolar plates. The cells have macroscopic dimensions in all directions and are made from a large number of components, which are then pressed together in the cell stack using pressure. Such a stack is e.g. in US Pat. No. 4,175,165 "Fuel Cell System utilizing ion exchange membranes and bipolar plates", Inventor: Otto S. Adlehart

At the heart of such a cell stack are the membranes, which are typically coated on both sides with electrochemically active catalyst material are. The membrane areas usually move between 1 and 1500 cm ² , the membrane thickness between 30 and 200 μm. Gas-permeable and electronically conductive current distributors press on the two catalyst-coated surfaces of the membrane, which ensure good electronic transverse conductivity and a homogeneous gas supply to the membrane. The current distributors are separate structures with a thickness of, for example, 200-500 μm. This is followed on both sides by the electronically conductive bipolar plates, from which the voltage can be tapped and which contain internal channels for the gas supply to the respective electrode. They have thicknesses in the range of a few millimeters to centimeters. A seal is provided between the membrane side and the bipolar plate to ensure the gas tightness of the cell stack. This entire arrangement is to be pressed together, for example, by screwing in order to achieve electrical contacting of the membrane on the one hand and gas-tightness on the other.

In the course of the smallest possible volume of the cell stack and the lowest possible electrical losses, an attempt is made to make the arrangement described above as small and thin as possible. In principle, such a miniaturization with a concept according to the above prior art is only possible to a very limited extent: the entire arrangement must be pressed together, so that the individual components (membrane, plates, etc.) have strong mechanical and mechanical properties have to withstand all non-homogeneous stresses. A drastic reduction in the thickness of the components involved is therefore ruled out, since very thin components inevitably break or would tear. A miniaturization of the cell area in the square millimeter range, for example to obtain high voltages with only low currents, also reaches the limits of feasibility with this concept. A mechanical assembly of hundreds of smallest individual parts and their screwing is not feasible from a practical point of view.

In addition, a fuel cell arrangement is described in DE 39 07 485 AI. This is a so-called SOFC (Solid Oxide Fuel Cell) arrangement. This type of fuel cell is operated in a temperature range between 800 and 1000 ° C and for this reason temperature-resistant inorganic materials must be used accordingly. The electrolytes are ion-conducting oxide ceramics and the guiding mechanism takes place almost exclusively via oxygen ions. In addition to the electrolyte, the carrier material also used according to DE 39 07 485 is a porous ceramic material, such as, for example, magnesium aluminum spinel (MgAl ₂ 0 ₄ ) or zirconium oxide. In addition to the high demands on the materials used, it is disadvantageous that the previously known fuel cell arrangement must also have correspondingly large dimensions, so that the use cannot be carried out in any shape and anywhere.

In addition to the advantages which are undoubtedly present, ceramic materials also have the disadvantage that they are very brittle. Once a shape has been specified, it can no longer be changed and only rigid structures can be maintained. A subsequent change in shape or geometry or an adaptation to different site modifications is no longer possible.

DE 43 29 819 A1 also describes a so-called strip membrane, which as an electrochemical cell with at least one core region forming the strip membrane, on each of which polymeric solid electrolytes are applied as an electrode layer on both sides and in which several individual cells are connected in series are trained. Such a strip membrane can then be used in fuel cells. However, the low strength must be taken into account here and a corresponding housing receptacle must be carried out. Furthermore, it is disadvantageous in this solution that for achieving higher

Voltages, a correspondingly large number of individual cells must be connected in series, which require a correspondingly large area requirement. As a result, an insert cannot be variably adapted to the most varied of locations.

Another arrangement of fuel cells based on a high-temperature solid electrolyte is known from DE 40 33 284 A1. This also belongs to the group of SOFC fuel lines already mentioned, with the disadvantages already mentioned in the description of the fuel cell arrangement according to DE 39 07 485.

The object of the present invention was therefore to propose a new electrochemical solid electrolyte cell system with which a miniaturization of a cell stack in the area and / or in the thickness of the components should be possible. The object is achieved in relation to the cell system by the characterizing features of claim 1, according to the method by the characterizing features of claim 21 and according to use by the characterizing features of claims 24 and 25. The subclaims show advantageous configurations.

According to the invention, it is therefore proposed to apply a fuel cell system in layered technology to a flat, gas-permeable, non-conductive support body. As a result, the cell can be produced and used as a chip analogously to the electrically integrated circuits.

It is essential to the invention in the subject of the application that a flat, gas-permeable, non-conductive, flexible support body is used, on the surface of which the cell is then applied using layering technology. The cell applied using layering technology is only one-sided, i.e. arranged only on one surface, so that in connection with the gas-permeable support body it is possible to lead a first partner involved in the fireplace insert reaction on the side opposite the cell area through the gas-permeable support body to the cell and the second Lead reactants directly to the surface of the cell.

It should be particularly emphasized in the cell system according to the invention that this structure makes it possible to arrange and electrically connect a plurality of cell regions on a support body. As a result, an arrangement can be implemented that is known from the prior art Technology known stack design corresponds.

In principle, at least up to 1,000,000 cell areas can be arranged in this way analogous to the integrated circuits.

According to the invention, a cell area is understood to mean an insulated structure of a cell, each consisting of a first porous, flexible, electrically conductive electrode layer, a proton-conducting membrane layer and a second porous, flexible, electronically conductive electrode layer. These individual cell areas can each be applied by means of appropriate layer technology (e.g. mask technology) and interconnected by means of suitable electrical contacts. The layer technology used according to the invention thus opens up numerous possibilities for connecting the individual cell areas in series. For example, several of the cell areas described above, preferably 2-10,000, can be connected in series, so that a one-dimensional cell arrangement is created. With the cell system according to the invention, however, any arrangement of cells connected in series is also possible. Such two-dimensional arrangements can be designed in such a way that several cell rows are arranged one behind the other in any shape on the supporting body, or else that several individual cell rows, preferably 2 to 10,000, are formed, which are then connected in parallel with one another (redundant arrangement ).

The basis of the cell system according to the invention is thus the gas-permeable, flat, non-conductive, flexible supporting body. This support body serves as a mechanical basic structure for all subsequent layers to be applied. At the same time, the fuel supply for the one electrode also takes place through this support body. Since, according to the invention, a plurality of cells can also be applied next to one another on the support body, the support body need not be conductive, since otherwise the individual cells would be short-circuited via the support body. The support body used in accordance with the invention has a thickness of 10 μm to 10 mm and an area of 1 mm ² to Im ² . The dimensioning of the support body depends on the application, ie whether one or more cells are applied to the surface. The support body is preferably a non-conductive, gas-permeable, flat membrane. The materials for the support body are typically polymeric supports made of, for example, polysulfone. Such porous membranes can have symmetrical, ie the same membrane structure over the entire membrane cross-section, or asymmetrical, ie changes in the membrane structure over the membrane cross-section. Composite membranes are also possible. An overview of materials for the supporting body that can be used according to the invention can be found, for example, in "Membranes", Prof. Dr. Eberhard Staude, from Ulimann's Encyclopedia of Industrial Chemistry, 4th edition, 1978, vol. 16, pages 515 to 535.

In contrast to the SOFC fuel lines, the PEMFC (polymer electrolyte membrane fuel cell) fuel lines designed according to the invention typically work in a temperature range between 80 and 100 ° C. and the ion conduit does not use the oxygen ions but proto Conductive membranes, which usually consist of proton-conducting polymer material. Since the solid electrolyte cell system designed according to the invention consists of polymer materials, they are suitable for use in PEMFC fuel lines and, in particular, are designed to be very light and flexible, which enables corresponding flexible structures. Porous, gas-permeable films can be produced inexpensively with the polymer materials, it being possible to use the phase inversion method known in membrane technology. A polymer solution is immersed in a cell bath and the solution is separated into a polymer-rich and a polymer-poor phase. After the membrane has been dried, a gas-permeable, porous structure can be obtained. All other layers of the cell system according to the invention (ion-conducting plastic film or conductive structures) can then be applied to the porous polymer support thus obtained, which is also flexible. A completely flexible layer structure is achieved. The cell system thus produced then takes the form of a flexible film which can be used in a wide variety of forms. For example

Winding modules are produced, the above-described film structure of the cell system according to the invention being overlaid with a second non-functional, non-conductive, thin, flexible plastic film and wound up accordingly. Gas spaces should be formed between the latter plastic film and the "fuel cell film", so that the fuel cell film with hydrogen on one side and with on the other side Oxygen or air can be brought into contact, so that a functional fuel cell with a high output voltage that can be achieved by the possibility of series connection is formed. If, for example, the cell system is designed as a winding module, the use of the plastic starting materials means that the edges on the two end faces of the winding module can be sealed by simply gluing or welding the plastics with a suitable closure (cover). The closures are made of a stable, non-conductive, gas-impermeable material.

With the cell system designed according to the invention, in addition to being used as a winding module, a wide variety of structures and shapes can be formed, so that it is possible to provide fuel cells in a relatively small space, which, if desired, can deliver a high output voltage .

The surface of the support body usually has an area of 1 cm ² to 1000 cm ² .

An overview of this is e.g. from "membranes",

Prof. Dr. Eberhard Staude, from Ulimann's Encyclopedia of Industrial Chemistry, 4th edition, 1978, vol. 16, pages 515-535.

The electrode layers deposited on the support body described above by means of layer technology typically have a thickness of 10 nm to 100 μm. The materials for this are all, in and of themselves, already known from the prior art. knew electrode materials in question.

A prerequisite for the electrode layers is that they are electronically conductive and catalytically active. As a rule, suitable catalysts are necessary for the course of the electrochemical partial reactions in order to avoid high transition voltages. For a hydrogen-oxygen fuel cell, platinum is typically used as the electrode material catalyst. Other examples of electrode materials are platinized carbon or iridium. Additives such as Hydrophobie¬ be included.

In the membrane layer, which is likewise deposited on the first electrode layer by means of layer technology, it is important that it is proton-conductive in order to ensure the ionic charge transport between the two electrodes. Typically, polymers have sulfonic acid, carboxylic acid or

Phosphonic acid groups contain the property of proton conductivity in the presence of water. Examples are sulfonated polysulfones or sulfonated polyether sulfones. Another possibility is the organic-inorganic polymer class of the ormolytes

(ORGANIC MOdified ceramics elektroLYTES), such as, for example, aminosile, poly (benzylsulfonic acid) siloxanes or sulfonamidosile, all of which are produced via sol-gel processes. Aminosils are obtained from a solution of aminated organotrisiloxane, an acid HX and water. Materials of the general formula SiO _3/2 , R- (HX) _X , 0 <x <0.5 are obtained via a sol-gel process. An example of an aminosil is Si0 _3/2 (CH ₂ ) ₃ NH (CH ₂ ) ₂ NH ₂ - (HCF ₃ S0 ₃ ) ₀₂ .

Inorganic compounds can also have proton conductivity, especially at higher temperatures. Examples are modified alkaline earth metal ceramates or zirconates such as

SrCe ₀₉₅ Yb ₀ . ₀₅ O ₃ ^ or CaZr ₀₉₅ In ₀₀₅ O ₃ ^.

According to the invention, it is proposed according to a preferred embodiment to arrange several of the cell areas described above on the support body and to connect them electronically. This embodiment is particularly preferred since, analogously to the stack construction known from the prior art, very high output voltages can be achieved by connecting the individual cells in series. According to the invention, this is achieved in that the electrical connection via one, the proton-conducting membrane layers from neighboring ones

Electrical contact separating cell areas, not proton-conducting. It is important that the proton conduction between the individual membranes is interrupted. At the same time, an electronic conductivity of z. B. the membrane underside of the first cell area to the membrane top of the second cell area can be guaranteed. This is now achieved in that an electrical contact separates the two membrane layers, which adjoin one another on the end faces, and is in contact with the lower electrode layer and with the upper electrode layer of the adjacent cell area. The contact can be designed so that an electrode surface between the two Is passed through membranes and is in contact with the electrode area opposite the first electrode area of the next cell area. This contact is preferably designed in such a way that it is not porous and not catalytically active in the area of the proton-conducting membrane. Examples of such materials are titanium or conductive polymers. The invention further provides that, in addition to the electrical contact, an insulating layer, ie non-conductive areas, which can also be applied by means of layer technology, is arranged between the contact and the membrane. These non-conductive areas, ie insulating layers, must not be ionically or electronically conductive. Metal oxides such as aluminum oxide or non-conductive polymers such as polysulfones are therefore typically used as materials.

In addition to the cell structure described above, it is also possible to apply narrow strips or grids of electronically conductive material to the electrode surfaces. This leads on the one hand to an improvement in the transverse conductivity of the electrode layers and on the other hand to an improvement in the stabilization of the mechanical properties. This embodiment is advantageous when there is strong mechanical stress on the electrode surface, which e.g. this is the case when working with ion-conducting electrolytes, since this can lead to volume changes in operation due to the absorption and discharge of water.

The substances are applied by typical / J i. O? - 14

Methods of layering technology, such as sputtering, CVD processes, plasma-assisted CVD processes, plasma polymerization, sol-gel technology, electroplating or coating from solution or from suspensions with powders. Metal layers can be applied by sputtering processes, metal oxides are also accessible by reactive sputtering. CVD processes, e.g. the decomposition of organometallic starting compounds is made possible by metal oxide layers, with plasma-assisted CVD coatings being suitable for temperature-sensitive substrates. For example, thin platinum layers are accessible through the decomposition of TrCyclopentadienyltrimethylplinin in the plasma. Organic layers are also accessible, for example, by plasma polymerization of ethylene or other organics. The incorporation of carboxylate groups in the plasma polymerization enables the production of proton-conducting plasma polymers. Ormolytes as proton conductors are produced, for example, by means of the sol-gel process, other sulfonated polymers can be applied as a solution. Thus sulfonated polysulfones generally dissolve well in dimethyl sulfoxide and can thus be applied in a viscous form.

Suitable masks during the deposition process or covering with photoresists enable the application of geometrically defined areas, as are necessary for the integrated fuel line system.

Since the integrated fuel cell is self-supporting, simple encapsulation in plastic housings is possible. After applying all layers The layered fuel cell system is welded or cast into the corresponding plastic housing on the supporting body.

As described above, it is thus possible to weld or pour the fuel cells into a corresponding plastic housing. This way of installation also makes it possible, if cooling of the cell is necessary, to do this by applying cooling fins.

The above-described concept according to the invention for electrochemical electrolyte cell systems is suitable on the one hand, e.g. To flow hydrogen or methanol, also for water electrolysis cells.

Further features, details and advantages of the invention result from the following description of three embodiments, as well as from the drawings.

Fig. 1 shows the cross section through the schematic

Structure of a cell system according to the invention with an additional insulating

Layer;

FIG. 2 shows the structure analogous to FIG. 1, but with an insulating layer that only partially projects into the membrane in cross section;

Fig. 3 an inventive structure analog

1, but here only with an electrical contact; 4 the one-dimensional arrangement of four individual cells one behind the other in a top view;

5 shows the two-dimensional arrangement of several cell rows one behind the other in a top view;

6 a in side view and cross section the installation of a cell system according to the invention in a housing, and

Fig. 6 b in the front view;

7a shows a further embodiment relating to the installation of the cell system in a housing, but here with an integrated gas supply;

Fig. 7 b this arrangement in the front view.

8 a shows the installation of several cell systems in one housing, again in cross section,

Fig. 9 the integration of water cooling in a housing

10 shows a structure according to the invention in the form of a winding module in cross section,

11 shows a further exemplary embodiment using additional gas-impermeable, non-conductive foils and

12 shows an arrangement in which that in FIG shown embodiment is wound on a body.

1 shows, in cross section, the structure of a cell system according to the invention using the example of a fuel cell.

In the embodiment according to FIG. 1, four individual cells (cells 1-4) are connected in series one after the other. The cell 1 is formed by the cell area 3 and a part of the supporting body which is assigned to this area 3. The basis of the cell system according to the invention is the gas-permeable, flexible support body 1. The gas-permeable support body 1 is shown in FIG. 1, as in the following figures, only for better clarity in the form of a perforated support body. However, the invention includes all variants of a support body, provided that they are gas-permeable. The support body can accordingly itself be made of porous material or be made of non-porous material and have corresponding openings for the gas inflow. It is also possible to use a support body which is otherwise made from a closed material, but which has corresponding openings for the gas flow. The dimensions of the supporting body, ie the thickness and the surface, are selected depending on the conditions of use and the desired output voltages. The thickness is in the range from 10 μm to 10 mm, the surface in the range from 1 mm ² to 1 m ² . In order to produce the cell system according to the invention, a likewise flexible insulating technique is then applied to the gas-permeable, flexible support body 1 in a first step on its surface 2 at certain intervals using layer technology. rende layer 15 of non-conductive material applied. This non-conductive material serves to isolate the cell regions 3 that then arise. The thickness of the insulation 15 is in the range from 10 nm to 1 mm. In the embodiment according to FIG. 1 there are three insulating layers 15 applied to the supporting body 1. The height of the layer is chosen so that the upper edge is almost flush with the membrane layer 8 to be produced. In the next step, the gas-permeable support body 1 is coated with electronically conductive, flexible material for producing the first electrode layer 7. The electronic partial reactions, for example, hydrogen oxide oxidation, then take place on this electrode layer 7. This layer (first electrode) must not be tight, but, like the supporting body 1, must have a certain porosity. In the following step, small, electronically conductive areas which represent the electrical contact 12 are then applied directly next to the insulating layer 15 and on the first electrode layer 7. A flexible proton-conducting layer is applied in the depressions now formed between the insulating layer 15 and the conductive contact 12. This proton-conducting layer then forms the membrane layer 8. The membrane layer 8 is in contact with the conductive material of the electrode layer 7 on the underside. A coating is then again carried out with an electronically conductive flexible material for producing the second electrode layer 11, on which the other partial electrochemical reaction takes place (second electrode). In the case of the above-described example of a hydrogen-oxygen fuel cell, the oxygen reduction then takes place here. This layer must be such that a three-phase contact between the supplied gas, second electrode 11 and

Membrane layer 8 is possible, i.e. it must not be a dense layer. Furthermore, the layer 11 must be applied in such a way that an electronically conductive connection between the lower electrode 7 of one cell and the upper electrode 11 of the following cell is achieved with the aid of the electrical contact 12. An internal electrical series connection of the individual cells 1 to 4 is thus realized and the sum of all cell voltages can be tapped at the first upper electrode with the connection 20 and the last lower electrode with the connection 21.

2 now shows a further embodiment of a cell system according to the invention. The structure corresponds essentially to the structure according to FIG. 1, however, according to FIG. 2, the connection is realized differently by means of the electrical contact. The connection according to FIG. 2 is carried out here by an electrical contact 13, which is designed in such a way that it directly connects the upper electrode layer 7 to the lower electrode layer 7. The electrical contact 13 is consistently formed from a dense material. In the embodiment according to FIG. 1, the dense material was only arranged in the area of the proton-conducting membrane layer. Such an arrangement comes into play, for example, when the electrical contacts (13) are only inserted in the last manufacturing step, for example by using corresponding conductive ones Structures are inserted from above into the cell system with pressure. In a modification of the exemplary embodiment according to FIG. 1, the insulating layer 16 is not designed here in such a way that it extends over the entire thickness of the membrane layer 9, but only partially.

With this embodiment too, a series connection of the cell region 4 according to the invention can be implemented. 3 now shows an embodiment in which the insulating layers are entirely dispensed with. In this embodiment, the membrane layer 10 is formed in such a way that it is guided down to the supporting body 1 in the area of the electrical contact 14. This also makes it possible to implement a series connection of the cell region 5.

It is essential in all of the embodiments according to FIGS. 1 to 3 that the individual cells 3, 4, 5 are connected in series in series, the electrical contact 12, 13, 14 having to separate the two adjacent membrane layers.

FIG. 4 now shows the cell structure according to the invention according to FIG. 1 in a top view. The cells 1 to 4 arranged one behind the other can be seen, the individual voltages of which, according to the series connection according to FIG. 4, add up to a total voltage which can be tapped off at the connections 20 and 21. This arrangement of the individual cells is an arrangement in one direction.

5 now shows an embodiment in which the individual cells are arranged so that they expand in two directions, which is easily possible with the aid of the layer technique. 5 shows this using the example of 16 individual cells, 4 cells (cell range 1-4) being arranged in each axis direction. All cells are mounted on the supporting body 1 and connected in series according to the principle described in FIG. 1, so that 16 times the output voltage is available compared to an individual cell. The voltage can then be tapped at the connections 20 and 21. In the embodiment according to FIG. 5, the support body regions which are not covered by the cell arrangement are coated with a non-conductive substance 40 in such a way that no gas penetration occurs from the bottom to the top. The sequence and type of electrical connection in a cell arrangement in two directions is shown as an example in FIG. 5. Other arrangements and interconnections are also possible. Mixed series / parallel connections can be used in this way. For example, 4 cells are then connected in series, and these arrangements are then connected in parallel by applying conductive layers, so that redundant power supplies are available which, even after the failure of a single cell, remain operational at full voltage.

FIGS. 6 to 9 now show, by way of example, how the fuel cell according to the invention can be introduced into a plastic housing 17, 18, 19 simply by encapsulation. 6 a shows an example in the side view, FIG. 6 b in the front view. The integrated fuel cell 22 is welded or cast in a gas-tight manner into a non-conductive plastic housing 17, openings 23, 24 being provided on both sides of the cell for the fuel supply. hen are. The electrical connections 25, 26 of the cell are also encapsulated and are led to the outside as a metal contact.

FIGS. 7a and 7b show a further variant, for an advantageous gas supply of several integrated fuel cell systems. Here, too, the integrated fuel cell 22 is welded / poured in a gas-tight manner into a non-conductive plastic housing 18, but channels 27-30 running through the entire cell for fuel supply and removal are present. In the example of a hydrogen-oxygen cell, there was therefore a hydrogen-supply channel 27, which is connected to one side of the integrated fuel cell 22, and an oxygen-supply channel 30, which is connected to the other side of the integrated fuel cell. Any inert gases can be discharged through the discharge channels 28 and 29 for each side of the integrated fuel cell. The electrical connections of the cell 25, 26 are also encapsulated and are led to the outside as metal contacts. In this arrangement, a large number of these encapsulated cells can be arranged one behind the other via seals, the channels meaning a central fuel supply for all cells.

The encapsulation technique, however, also enables the installation of several integrated fuel cell systems in a plastic housing 19, as shown in FIG. 8.

If cooling of the cells becomes necessary, this can be done, for example, by applying heat sinks. Metallic heat sinks, for example made of aluminum, can be glued onto the cell. Water cooling is also possible (FIG. 9), in which case, in addition to the fuel supply channels 27-30, a channel for the water supply 31 and a channel for the water discharge 32 are integrated in the housing 33. The front and back of the housing contain corresponding large-area depressions 34, the actual cooling structures then being formed when several modules are assembled, for example by gluing, welding or by means of seals and pressure.

If only a single module is to be cooled, the depressions 34 described above are to be integrated as cavities in the housing.

It is possible in a further variant, the gas-permeable support body, through which the fuel gas flows, serving as a heat exchanger, which means that the coolant channels run through this support body.

The plastic housings 17, 18, 19 and 33 are preferably made of a flexible material. The housing walls and the fuel cells 22 are kept at a distance, so that the gas supply to the fuel cell 22 can take place without interference. In the case of the examples according to FIGS. 6a, 7a, 7b, 8 and 9, spacers made of non-conductive material, not shown there, can be used.

FIG. 10 shows a cross section of the construction diagram of a fuel cell winding module based on the described flexible fuel cell film, which is particularly advantageous and can be used in a small space.

The structure initially consists of the fuel cell film, which in the variant shown here consists of the porous support body 40, the electrodes 41 on both sides, the polymeric solid electrolyte 42, the electronically conductive regions 43 and the insulation regions 44. This fuel cell film is wound up together with a non-conductive and gas-impermeable film 45, so that two gas spaces - 46 and 47 - which are separate from one another are created. In these gas chambers chemical Energieträ¬ ger be supplied for the fuel cell foil, in the case of H _2/0 ₂ or H ₂ / air fuel cell εind this spielεweise examples in the gas space 46 and in the gas space 47 Wasserεtoff air.

The electrodes 41 applied on both sides of the polymer electrolyte regions thus receive the energy carriers required for the oxidation and reduction processes of the fuel cell. In order for this fuel supply to be possible, there must be spaces between the fuel cell film and the non-conductive separating film 45, which are produced, for example, by spacers 48. Such spacers can practically be produced by polymer networks which are co-wound in the module and generate free volume for a glass flow. Another possibility is that no spacers are used, but rather that small channels are provided in the separating film 45 on both sides are located, through which gas can flow to the electrodes. The spacers 48 can, however, also be used for cooling, and coolant can be passed through a tubular or tubular design. The end faces, which are not recognizable in the illustration, are particularly advantageous

Winding modules are sealed gas-tight with cover-shaped closures, which consist of a non-conductive material.

FIG. 11 shows a further, universal and inexpensive possibility for designing the invention. First 3 foils are needed and placed one on top of the other. A gas-impermeable, non-conductive film 50, a fuel cell film according to the invention and a further gas-impermeable, non-conductive film 52. Such a combination has a gas-impermeable film on both the top and bottom and is therefore gas-tight on both sides. So it does not have to be completely wound in itself as in Figure 10, but can be wound on any curves or body.

The two gas spaces required are located between foils 50 and 51 and between foils 51 and 52 and, as already described, can be produced by inserting porous foils or meshes between foils 50 and 51 on the one hand and foils 51 and 52 on the other hand .

The arrangement shown in FIG. 11 is then wound up, for example onto a body 53, as shown in FIG. The gas can be supplied in different ways: On the one hand, the sides A and D (FIG. 11) can be sealed gas-tight between the foils 50, 51 and 52 by gluing, welding or by inserting strips of sealing material between the foil ends. In addition, the space between film 50 and 51 is sealed on side B and the space between film 51 and 52 is sealed on side C. After winding, the gas is supplied on the sides of the roll, for example hydrogen on one side (wound side) B), and oxygen is fed on the other side of the roll (wound side C).

On the other hand, the sides B, C and D (FIG. 11) can each be sealed gas-tight between the foils 50, 51 and 52 by gluing, welding or by inserting strips of sealing material. The gas is then supplied and removed, for example, for hydrogen on side A between foils 50 and 51 and for oxygen between foils 51 and 52.

In both cases, guiding structures can ensure optimal feeding of the gas to the electrodes. The gas guiding structures can be channels, for example, which are integrated in the impermeable foils 50 and 52.

Suitable materials for the films are preferably materials which can be produced as a flexible film and which can withstand the conditions in the fuel cell, ie which are resistant to oxygen, hydrogen and hydrolysis. Examples are films made of polysulfones or perfluorinated materials can be used.

Claims

claims

1. electrochemical cell electrolyte system, consisting of a flat gas-permeable, non-conductive support body (1), in which on one surface (2) at least one cell area (3, 4, 5), consisting of a first porous, electrically conductive electrode layer (7), a proton-conducting membrane layer (8, 9, 10) and a second porous, electronically conductive electrode layer (11) are applied one above the other by means of layer technology.

2. Elektrochemischeε Feεtelektrolyt-Zellεystem according to claim 1, characterized in that 2 - 1,000,000 cell areas (3,4,5) are arranged on the support body and electrically connected.

3. Elektrochemiεcheε solid electrolyte cell system according to claim 1 or 2, characterized in that 2 - 10,000 cell areas (3,4,5) are connected in series in a row.

4. Elektrochemischeε Feεtelektrolyt-Zellεystem according to claim 3, characterized in that 2 - 10,000 rows are connected in parallel. 5. Electrochemical solid electrolyte cell system according to at least one of claims 1 to 4, characterized in that the electrical connection via one, the proton-conducting membrane layers (8, 9, 10) from adjacent cell areas (3, 4, 5 ) separating, non-proton-conducting, electrical contact (12, 13, 14), this being an electrode surface (7) of a first cell area (3, 4,

5) with the opposite electrode surface (11) of the next one

Cell range connects.

6. Electrochemical solid electrolyte cell system according to claim 5, characterized in that the electrical contact (12, 13, 14) in the area of the proton-conducting membrane layers is not porous and is not catalytically active.

7. Elektrochemiεcheε solid electrolyte cell system according to claim 5 or 6, characterized in that between the elec¬ tric contact (12,13,14) and the neighboring, proton-conducting membrane layer (8,9,10) additionally one, by means of layering technology ¬ brought, insulating layer (15,16) is arranged.

8. Electrochemical solid electrolyte cell system according to at least one of claims 1 to 7, characterized in that on the electrically conductive electrode layer (7, 11), electronically conductive material, e.g. B. is applied in the form of strips or bars.

9. Electrochemical solid electrolyte cell system according to at least one of claims 1 to 8, characterized in that the support body (1) is a non-conductive, gas-permeable, flat membrane which can be constructed symmetrically, asymmetrically or as a composite membrane .

10. Electrochemical solid electrolyte cell system according to at least one of claims 1 to 9, characterized in that the material of the support body (1) consists of inorganic oxide materials such as aluminum oxide, or of polymeric materials such as polysulfones, or of such carrier-supported materials.

11. Elektrochemischeε solid electrolyte cell system according to at least one of claims 1 to 10, characterized in that the material for the electrode layers (7, 11) is selected from

Elements of subgroup VIII, and their alloys, oxides, mixed oxides, or mixtures thereof or from mixtures or composites of the materials mentioned with carbon.

12. Elektrochemischeε solid electrolyte cell system according to at least one of claims 1 to 11, characterized in that the material for the proton-conducting membrane layer (8,9,10) is selected auε polymeric ion conductors, organic-inorganic ion conductors, or inorganic ion conductors such as alkaline earth metal zirconates .

13. Electrochemical solid electrolyte cell system according to at least one of claims 1 to 12, characterized in that the material for the electrical contact for switching the cell areas in the area of the membrane layer are metals such as titanium or conductive carbon or electronically conductive polymers.

14. Electrochemical solid electrolyte cell system according to at least one of claims 1 to 13, characterized in that the insulating layer (15, 16) is an organic non-conductive polymer such as polysulfones, plasma-polymerized polymer layers or inorganic materials such as aluminum oxide.

15. Electrochemical solid electrolyte cell system according to at least one of claims 1 to 14, characterized in that 1 - 10,000,000 cell systems in a non-conductive plastic housing

(17, 18, 19) are cast in or welded in, the connections of the cell being cast around and being led to the outside as a contact.

16. Electrochemical solid electrolyte cell system according to claim 15, characterized in that 1-2000 encapsulated cell systems are arranged one behind the other by means of seals and have central material supply or removal channels.

17. Electrochemical solid electrolyte cell system according to at least one of claims 1 to 16, characterized in that one consists of a supporting body (40), the electrodes (41), solid electrolyte (42) existing flexible film together with a non-conductive, gas-impermeable flexible film (45), at a distance forming a gas space (46), are arranged and wound, so that a second gas space (47) is formed and the end faces of the winding module-shaped system are closed.

18. Electrochemical solid electrolyte cell system according to claim 17, characterized in that in the two gas spaces (46) and (47) spacers (48) are arranged.

19. Electrochemical solid electrolyte cell system according to at least one of claims 1 to 16, characterized in that the cell system is designed as a flexible film (51) which is surrounded on both sides by non-conductive separating films (50) and (52) and the sides (A), (B), (C) and (D) are connected to one another in such a way that two gas spaces are formed on both sides of the flexible film (51) with a separate gas supply.

20. Electrochemical solid electrolyte cell system according to claim 19, characterized in that the foils (50, 51, 52) are wound around a body (53).

21. A method for producing an electrochemical solid electrolyte cell system according to at least one of claims 1 to 20, characterized in that on the support body a first electrically conductive electrode layer, a proton-conducting membrane layer and a second, porous, electronically conductive membrane layer are deposited in succession by means of film technology methods which are known per se.

22. The method according to claim 21, characterized in that the layers are produced by means of PVD, CVD, thermal or plasma-assisted decomposition of organometallic compound, galvanic methods or pressing processes.

23. The method according to claim 21 or 22, characterized in that the generation of defined geometrical structures of the layers to be applied takes place by means of masks which are placed on the substrate or by means of suitable photoresists.

24. Use of the electrochemical solid electrolyte cell system according to at least one of claims 1 to 20, as an electrolysis system which splits water into hydrogen and oxygen.

25. Use of the electrochemical solid electrolyte cell system according to at least one of claims 1 to 20, as a fuel cell which exudes hydrogen or methanol.