Stacked structure for electrochemical energy converter and method for manufacturing said stacked structure

Abstract

The invention relates to a stack structure (10) for an electrochemical energy converter (80), comprising: a bipolar plate (11); a membrane electrode unit (12); a process fluid guiding structure (13) for guiding a process fluid in a stacking direction (14); frame seals (15) which are fastened to the membrane electrode unit (12) in each case in an edge region of the membrane electrode unit (12); process fluid seals (16) for sealing an edge region of the process fluid guiding structure (13), the process fluid seals (16) each having an inner sealing section (18), which is positioned between the process fluid guiding structure (13) and the membrane electrode unit (12) as viewed in the transverse direction (19); an edge seal (17) for sealing an edge region of the frame seal (15) and / or an edge region of the bipolar plate (11); and spacer elements (20), which are positioned and / or configured in each case between the two inner sealing sections (18) in the stacking direction (14) and each have a passage opening (21) for guiding the process fluid from the process fluid guiding structure (13) to the respective membrane electrode unit (12) in the transverse direction (19). A method for manufacturing such a stack structure (10).

Description

Technical Field

[0001] The present invention relates to a stack structure for an electrochemical energy converter, in particular a fuel cell stack, and also to a method for manufacturing the stack structure. Background Art

[0002] An electrochemical energy converter in the form of a fuel cell stack consists of a large number of essentially identically constructed single cells, each consisting of a bipolar plate and a membrane electrode assembly (MEA), which are stacked in a stack. Different media or process fluids (usually fuel, oxidant and coolant) are guided in different layers in the corresponding single cells. The process fluid is supplied to the fuel cell stack via a manifold extending in the stacking direction or a corresponding process fluid guiding structure, and is usually discharged again through the manifold of the process fluid guiding structure. This means that the process fluid guiding structure usually has a channel for introducing the process fluid into the corresponding fuel cell and a channel for conducting the process fluid from the corresponding fuel cell. In the corresponding fuel cell, the so-called flow field or flow field in the active area ensures that the process fluid is distributed as evenly as possible on the active surface of the single cell.

[0003] The bipolar plate can consist of two or more single layers, which can be joined to each other by welding or bonding materials. A cooling medium (e.g. water) can be guided into the cavity formed between the two joined single layers. A process fluid (e.g. hydrogen or air) can be guided on the side facing away from the second single layer. The membrane electrode unit usually includes a catalyst coated membrane (CCM) and two gas diffusion layers (GDL), and the membrane electrode unit is located between the two bipolar plates. In addition, the membrane electrode unit may also include an additional reinforcement frame or a frame seal (Subgasket, sub-seal) made of one or more thin film layers, which at least partially surrounds the catalyst coated membrane of the membrane electrode unit on its outer periphery.

[0004] The various media spaces of a fuel cell stack must be sealed from one another and from the environment. For this purpose, different joining and / or sealing methods can be used, such as welding, bonding and the use of metallic and / or elastomeric seals. For example, the two layers of a bipolar plate can be sealed by welding, while the seal between the bipolar plate and the membrane electrode unit uses an elastomeric seal. The elastomeric seal can be fastened to the bipolar plate, to a separate carrier or to a component of the membrane electrode assembly, such as a frame seal or a gas diffusion layer.

[0005] The joining lines and / or sealing lines intersect in the transition region of the flow field. With regard to the configuration of the medium passages and the sealing structures necessary for this, various possibilities are known in the prior art.

[0006] DE 10 394 231 T5 describes that the sealing line in the area of ​​the medium lead-through can be arranged orthogonally to the stacking direction, so that the medium can be guided through the perforation in the bipolar plate on the seal. In the above embodiment, the bipolar plate must be implemented asymmetrically, and during the stacking process, the bipolar plate must be placed 180° rotated around the stacking axis relative to the adjacent bipolar plate. In patent applications US2012 / 0164560A1, US2009 / 0197147A1 and DE 10 248 531 A1, it is described that a metal-supported bead seal (combined with an elastomer seal mounted on the bead if necessary) can be used to seal the gas space on the anode and cathode sides relative to the sub-seal or frame seal. The medium lead-through can be realized by a perforation in the bead, so the cavity between the two layers of the bipolar plate must be sealed outwardly, and the process fluid flows through the cavity.

[0007] DE 10 2014 104 017 A1 describes how to implement the two layers of the bipolar plate at a distance from each other in the region of the process fluid supply between the manifold or process fluid guiding structure and the corresponding flow field. The process fluid can be guided in the space formed between the two layers of the corresponding bipolar plate between the process fluid guiding structure and the flow field. For the process fluid that is not between the two layers of the bipolar plate, but is guided on the outside of the two-layer bipolar plate in the active surface, a perforation can be set in one of the two layers of the bipolar plate in the sealing line so that the process fluid flows from the area between the two layers of the bipolar plate into the flow field on the anode side or the cathode side. The seal can be attached to the gas diffusion layer or the frame seal. The variant of attaching the seal to the bipolar plate in the injection molding process is advantageous from the perspective of manufacturing technology and function, but according to this teaching, the variant is not achievable, or can only be achieved at a high cost, because the welded bipolar plate composed of two layers does not provide mechanical support for the pressing edge of the injection mold for mounting in the region of the medium supply. It is also not possible to spray the seal onto a single layer, since in the subsequent welding process the weld line would cross or overlap the seal line and destroy the seal. Attaching the seal to a gas diffusion layer or frame seal places greater demands on the handling of the components, since these have a low (bending) stiffness.

[0008] In summary, in terms of achieving fluid connection between the process fluid guiding structure or manifold and the flow field or active area of ​​the fuel cell, there are many different solutions in the prior art, and these solutions have different advantages, but also disadvantages. Summary of the invention

[0009] Within the framework of the present invention, a stacking structure and a method for producing the stacking structure are now provided. In particular, a stacking structure according to claim 1 and a method for producing the stacking structure according to claim 7. Further embodiments of the invention are found in the dependent claims, the description and the drawings. Features relating to the stacking structure naturally also apply to features relating to the method according to the invention and vice versa, so that cross-references can always be made in the disclosure of the individual inventive aspects.

[0010] According to a first aspect of the present invention, a stack structure for an electrochemical energy converter is provided, comprising:

[0011] - bipolar plates,

[0012] - membrane electrode unit,

[0013] - a process fluid guiding structure for guiding the process fluid in the stacking direction,

[0014] a frame seal which is fastened to the membrane electrode unit in each case in the edge region of the membrane electrode unit, wherein the bipolar plates and the frame seal are arranged one above the other in the stacking direction,

[0015] a process fluid seal for sealing an edge region of the process fluid guide structure, wherein the process fluid seals each have an inner sealing section, which is positioned between the process fluid guide structure and the membrane electrode unit as seen in a lateral direction, the lateral direction being orthogonal to the stacking direction and extending from the process fluid seals in the direction of the membrane electrode unit,

[0016] - an edge seal for sealing an edge region of the frame seal and / or an edge region of the bipolar plate, and

[0017] Spacer elements which are respectively positioned and / or formed in the stacking direction between two inner sealing sections and respectively have a through-opening for conducting a process fluid in a lateral direction from the process fluid conducting structure to the respective membrane electrode unit.

[0018] In order to take into account the problems mentioned in the introduction to the description, it is proposed to implement the construction of the stacked structure with a spacer element according to the invention. For this purpose, a process fluid seal or a process fluid seal section can be positioned on the spacer element, respectively, which spacer element is configured with a reduced thickness in the stacking direction compared to a process fluid seal or a process fluid seal section not positioned directly on the spacer element. The process fluid can be reliably transported between the process fluid guide structure and the active area of ​​the membrane electrode unit or the corresponding fuel cell via the spacer element or the through-opening, respectively.

[0019] Another advantage of the present invention is that, due to the spacer element, all the individual layers of the bipolar plate can be laid flat on top of each other or configured accordingly in the distributor or transition area between the process fluid guiding structure and the active area. As a result, the individual layers can be easily welded to each other. In subsequent process steps, the process fluid seal (including the inner seal section) can be attached to the already welded bipolar plates, for example, by injection molding. Here, the pressing edge for the injection mold can be stably fitted or supported. In addition, the process fluid seal can be manufactured in only one process step. In the prior art mentioned at the beginning, two process steps are usually required for this.

[0020] By using injection molding, the seal can be produced quickly and easily in a contoured manner. As a result, the assembly force required for the corresponding process fluid seal and the functions and / or tolerance ranges that can be covered by the corresponding process fluid seal in the stacking direction can be increased compared to previous solutions, thereby also enabling a relatively favorable mechanical construction of the entire battery. This applies in particular to the process fluid supply of gases, such as oxidants in the form of air and fuels in the form of hydrogen, for example. For the coolant, which is usually guided between the individual layers of the bipolar plates, a slightly different but essentially similar construction can be selected.

[0021] The spacer elements can be configured as components of the battery components, i.e., as a part of the functional components of the stacked structure. However, the spacer elements can also be provided as independent functional components. The process fluid seal can have a transition section in the transition or distributor area, in which the thickness or height of the corresponding process fluid seal in the stacking direction changes from the maximum height to the height reduced in the transition area. The corresponding spacer elements can also have corresponding thickness changes, so that the relative compression of the process fluid seal in the transition area is basically within a similar range.

[0022] The spacer element can be shown in one or two directions in the stacking direction, i.e. orthogonally to the center plane, with reference to the center plane of the membrane electrode unit, and the center plane extends in the transverse direction. The spacer element can be made of plastic and / or metal. It is also feasible that the spacer elements are configured as corresponding units in pairs, i.e. mechanically connected to each other. Therefore, the spacer element unit can have two spacer elements mechanically connected to each other, wherein one spacer element has a through-hole for guiding a first process fluid from a process fluid guiding structure to a corresponding membrane electrode unit in a transverse direction, and the other spacer element has another through-hole for guiding a second process fluid different from the first process fluid from a process fluid guiding structure to a corresponding membrane electrode unit in a transverse direction. The mechanical connection between the two spacer elements can be made by a tab connection, in particular by a plate-shaped and / or film-shaped tab connection. The mechanical connection of two or more spacer elements can simplify the manufacture and handling of the spacer elements and minimize the tolerances in the stacking structure.

[0023] The process fluid seal is preferably configured in an annular manner. The frame seal can be understood as a so-called sub-seal. The bipolar plate and the frame seal are arranged in an overlapping manner in the stacking direction, which can be understood as the bipolar plate and the frame seal being arranged in an overlapping manner at least partially and / or in sections. In addition, it is feasible to arrange other functional components between the bipolar plate and the frame seal. This means that the bipolar plate and the frame seal do not have to be arranged directly in an overlapping manner. Preferably, in the stacking direction, the process fluid seal and the edge seal are positioned between the bipolar plate and the frame seal, respectively.

[0024] An electrochemical energy converter can be understood as an electrolyzer, a fuel cell system (especially a PEM fuel cell system) and / or a fuel cell stack. A bipolar plate can be understood as a single-piece or multi-piece bipolar plate, i.e. a bipolar plate having, for example, two mutually positioned plate elements or a single layer. A bipolar plate can also be understood as just a single layer. Therefore, a bipolar plate can have a corresponding single layer on the cathode side and a single layer on the anode side or be configured as such a single layer. The frame seal is preferably connected to the membrane electrode unit in a material-locked manner. In principle, the present invention is also applicable to a stacked structure having only one spacer element, one edge seal, one frame seal and / or one membrane electrode unit.

[0025] According to another embodiment of the present invention, it is feasible that in the stacking structure, the frame sealing part has two frame sealing layers, respectively, wherein the spacer element is positioned between the two frame sealing layers along the stacking direction. Therefore, when the frame sealing part is manufactured with two frame sealing layers or a single film layer, the spacer element can be inserted between the two frame sealing layers. The inserted spacer element can be attached to one of the frame sealing layers in a material-locked manner, or inserted between the frame sealing layers as an independent component during the assembly process of the stacking structure. The spacer element and its attachment to the frame sealing layer can be implemented so that one of the two frame sealing layers is implemented through in the transition area, and the other frame sealing layer has a recess in the transition area, and the spacer element is at least partially positioned in the recess. Therefore, in the stacking direction, the spacer element can protrude onto the area of ​​the recess.

[0026] Alternatively or additionally, it is possible at different positions of the stacking arrangement to position the spacer element in the stacking arrangement according to the invention directly between the frame seal and the inner sealing section in the stacking direction. In this case, the spacer element can be regarded as an alternative to a conventional tunnel sealing section. By using the spacer element, the desired passage opening can be easily and reliably provided in the transition area for guiding the process fluid. The spacer element can be clamped between the frame seal and the inner sealing section or positioned there under pressure. Preferably, the spacer element is respectively fastened to the frame seal in a material-locking manner.

[0027] According to another embodiment of the invention, it is possible to configure the spacer element as an integrated and / or integral component of the frame seal. This means that the spacer element can be a component of the frame seal and / or of one of the frame sealing layers. This makes it possible to provide the spacer element in a particularly stable manner in the stack. This can also simplify the production process of the stack.

[0028] It is also possible that in the stacking arrangement according to the invention the spacing elements each have a supporting structure for the supporting function in the stacking direction, wherein the supporting structure forms at least two through-opening channels extending parallel to one another in the through-opening or the corresponding through-opening volume. Thus, the spacing elements can each have a supporting structure so that the stacking arrangement does not deform or only slightly deforms in the stacking direction when the stacking arrangement is loaded with assembly forces and / or forces during operation of the stacking arrangement. The supporting structure can have a V-shaped, W-shaped, wedge-shaped, wavy and / or plate-shaped cross section.

[0029] Furthermore, it is possible in the stacking structure according to the invention that the bipolar plates are welded to each other by means of at least one weld, wherein at least one weld is configured in the stacking direction between two process fluid seals and / or between two inner sealing sections of the process fluid seal. This means that in the stacking structure according to the invention, the welding lines and the sealing lines can be superimposed or intersected with each other, thereby achieving a compact construction of the entire stacking structure. Furthermore, by covering with a sealing material, the welding lines can thus be at least partially protected from contact with the reaction medium, in particular the coolant, thereby, for example, preventing corrosion.

[0030] Another aspect of the present invention relates to a method for manufacturing a stacked structure of an electrochemical energy converter. The method comprises the following steps:

[0031] - Provide bipolar plates,

[0032] - providing a membrane electrode unit,

[0033] - providing a process fluid guiding structure for guiding the process fluid in the stacking direction,

[0034] - providing a frame seal which is fastened to the membrane electrode unit in each case in the edge region of the membrane electrode unit, wherein the bipolar plates and the frame seal are each arranged one above the other in the stacking direction,

[0035] - providing a process fluid seal for sealing an edge region of the process fluid guiding structure, wherein the process fluid seal respectively comprises an inner sealing section, which is positioned between the process fluid guiding structure and the membrane electrode unit as seen in a lateral direction, the lateral direction being orthogonal to the stacking direction and extending from the process fluid seal respectively in the direction of the membrane electrode unit,

[0036] - providing an edge seal for sealing an edge region of the frame seal and / or an edge region of the bipolar plate, and

[0037] The spacing element is positioned and / or configured in each case between two inner sealing sections in the stacking direction to form a through-opening for conducting the process fluid in the lateral direction from the process fluid conducting structure to the respective membrane electrode unit.

[0038] The method according to the invention thus has the same advantages as those described in detail with respect to the stacking structure according to the invention. The spacer elements can be made of plastic and / or metal. The spacer elements can be produced by injection molding, embossing, shaping, deep drawing, bonding, welding and / or cutting. It is therefore possible in the method according to the invention to inject the spacer elements as injection-molded components onto the frame seal. In this way, the spacer elements can be produced quickly and easily.

[0039] In the method according to the invention, the spacer elements can also be produced by plastic, in particular thermoplastic, shaping of the frame seal, thereby making it possible to achieve a particularly space-saving and logistically convenient stacking arrangement.

[0040] According to another embodiment variant of the invention, it is possible that in one method the frame seal has two frame sealing layers respectively and the spacer element is inserted as an insert component between the two frame sealing layers. This can also provide a relatively simple assembly process, by which the spacer element according to the invention can be positioned safely and securely at the desired position. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Further measures for improving the invention are described below in connection with various embodiments of the invention, which are schematically shown in the drawings. All features and / or advantages arising from the claims, the description or the drawings, including structural details and spatial arrangements, are essential to the invention, either individually or in any combination.

[0042] It schematically shows:

[0043] Figure 1 A top view of a stacked structure according to a preferred embodiment of the present invention,

[0044] Figure 2 A cross-sectional view of a stacking structure according to the present invention,

[0045] Figure 3 Another cross-sectional view of the stacking structure according to the present invention,

[0046] Figure 4 Another cross-sectional view of the stacking structure according to the present invention,

[0047] Figure 5 A top view of a partial section of a stacked structure according to the invention,

[0048] Figure 6 Another cross-sectional view of the stacking structure according to the present invention,

[0049] Figure 7 Another cross-sectional view of the stacking structure according to the present invention,

[0050] Figure 8 A vehicle having a stacked structure according to the invention, and

[0051] Fig. 9 Flowchart diagram for explaining the method according to the invention.

[0052] Elements having the same function and mode of action are provided with the same reference symbols in the figures. DETAILED DESCRIPTION

[0053] Figure 1 A top view of a stack 10 of an electrochemical energy converter 80 in the form of a PEM fuel cell stack is shown. The stack 10 has a bipolar plate 11 made of metal, a membrane electrode unit 12 and a process fluid guide structure 13, which has a plurality of manifolds or fluid channels in the stacking direction 14. More specifically, the stack 10 has a process fluid guide structure 13, which has two oxidant channels 31, two coolant channels 32 and two fuel channels 33, wherein only one of the two channels in each case has a channel section that is in fluid connection with one another. The membrane electrode unit 12 shown has a catalyst-coated membrane (CCM) 24, which is positioned between two gas diffusion layers (GDL) 23.

[0054] The stack structure 10 shown also has a distributor or transition area 67, wherein the distributor channel structure 64 is configured to guide the corresponding process fluid between the process fluid guiding structure 13 or manifold and the membrane electrode unit 12 or the active area 60 of the corresponding fuel cell. The active area 60 can also be understood as a so-called flow field. The oxidant supply line 36, the coolant supply line 37 and the coolant opening 38 are configured in the transition area. The stack structure 10 shown also has welds 34 at different positions. In addition, the stack structure 10 has a process fluid seal 16 and an edge seal 17, which will be further described in detail in the following figures. The process fluid seal 16 is composed of an elastomer, which is configured to surround the channels extending parallel to each other in the stacking direction in a corresponding annular manner, that is, around the corresponding oxidant channel 31, the corresponding coolant channel 32 and the corresponding fuel channel 33.

[0055] Figure 2 Shown according to Figure 1 The cross-sectional view of the section A-A shown in FIG. 1 extends through the oxidant channel 31 of the stack 10. This means that a process fluid flow 40 with an oxidant in the form of air occurs in the oxidant channel 31 shown. Figure 2 As shown in FIG. 1 , the stack structure 10 has a frame seal 15 or a sub-seal, which is fastened to the membrane electrode unit 12 in the edge region of the membrane electrode unit 12, more precisely, between the catalyst membrane 24 and the gas diffusion layer 23, and extends around the membrane electrode unit 12 in a frame shape. Figure 2As shown in FIG, the bipolar plates 11 or individual bipolar plate layers and the frame seal 15 are arranged one above the other in the stacking direction 14. The frame seal 15 has two frame seal layers. In the region of the process fluid seal 16 and in the region of the edge seal 17, the two individual layers of the bipolar plate 11 lie flat against each other. The process fluid seal 16 is produced simultaneously in an injection molding process and attached to both sides of the corresponding bipolar plate 11.

[0056] The process fluid seal 16 shown is configured and constructed for sealing the edge region of the process fluid guiding structure 13, wherein the process fluid seal 16 has an inner sealing section 18, which is positioned between the process fluid guiding structure 13 and the membrane electrode unit 12 as viewed in a transverse direction 19, which is orthogonal to the stacking direction 14 and extends in a direction from the process fluid seal 16 in each case toward the membrane electrode unit 12. The edge seal 17 is configured and constructed for sealing the edge region of the frame seal 15 and the edge region of the bipolar plate 11. Figure 2 1 and 2 , the stacking structure 10 is also shown with a spacing element 20, which is configured between two inner sealing sections 18 in the stacking direction 14 and has a through-opening 21 for guiding the process fluid between the process fluid guiding structure 13 and the corresponding membrane electrode unit 12 or active area 60 in the transverse direction 19. The spacing element 20 is positioned directly between the frame seal 15 and the inner sealing section 18 in the stacking direction 14. In the inner sealing section 18, the process fluid seal 16 is configured to have a height that is reduced in the stacking direction 14 in order to leave space for the corresponding spacing element. The spacing elements 20 each have a rounded outer contour to prevent damage to the frame seal 15 caused by the spacing element 20 as much as possible.

[0057] The bipolar plates 11 or the corresponding bipolar plate layers are not welded in pairs. Therefore, the corresponding bipolar plates 11 have weld seams 34 at different locations. Figure 2 , one weld seam 34 of the welded bipolar plate 11 is formed directly one above the other in the stacking direction 14 between two inner sealing sections 18 of the process fluid seal 16 . Another weld seam 34 is formed at another location between two further subsections of the two process fluid seals 16 .

[0058] Figure 3 Shown according to Figure 1 The section BB is shown in cross section, which extends through a coolant channel 32 of the stack 10. This means that a process fluid flow 40 with coolant respectively takes place in the coolant channel 32 shown and in the adjoining spacer elements 20. Figure 4 Show according to Figure 1, which extends through a fuel channel 33 of the stack 10. This means that a process fluid flow 40 with fuel in the form of hydrogen is respectively carried out in the fuel channel 33 shown and in the adjacent spacing elements 20. Depending on whether a plurality of spacing elements 20 or at least one spacing element 20 is provided for conducting an oxidant, a coolant or a fuel, different shape contours and / or material compositions can be provided in detail, for example to achieve the corresponding required sealing function. This means that the spacing elements 20 shown here do not necessarily all have the same shape and / or material properties.

[0059] Figure 5 A plan view of a partial section of a stacked structure 10 according to the present invention is shown. Figure 6 Shown along Figure 5 A cross-sectional view of section A-A is shown in FIG. Figure 6 An embodiment variant is shown in which the spacing element 20 has a supporting structure 22 for a supporting function in the stacking direction 14. The supporting structure 22 is designed essentially W-shaped and thus forms three through-hole channels extending parallel to one another in the through-hole 21.

[0060] Figure 7 Shown in Figure 5 A cross-sectional view of section BB shown in FIG. Figure 7 It can be seen particularly clearly in FIG. 1 that the spacer element 20 according to the present embodiment shown is positioned between two frame sealing layers 15 in the stacking direction 14 .

[0061] Figure 8 A vehicle 100 is shown with an electrochemical energy converter 80 in the form of a fuel cell system having a stack structure 10 as described above. The vehicle 100 also includes a fuel tank 70 and a motor 90, wherein the energy converter 80 is configured to generate current for the motor 90 from the fuel in the fuel tank 70. The motor 90 is configured to drive the vehicle 100.

[0062] Fig. 9 A flow chart is shown for explaining a method for producing the above-described stack structure 10 of an electrochemical energy converter 80. In a first step S1, bipolar plates 11, membrane electrode units 12, process fluid guide structures 13, frame seals 15, process fluid seals 16 (which each have an inner seal section 18) and edge seals 17 are provided and / or constructed. In a second step S2, spacer elements 20 are positioned and / or constructed in the stacking direction 14 between two inner seal sections 18 to form through-openings 21, which are configured for guiding the process fluid in the transverse direction 19 from the process fluid guide structure 13 to the respective membrane electrode unit 12.

[0063] The second step S2 does not have to be implemented after the first step S1. Depending on the type and / or manufacturing method of the spacer element 20, they can be formed at different points in the manufacturing process. For example, the spacer element 20 can be injected onto the frame seal 15 as an injection-molded component made of plastic. In this case, the process fluid seal 16 is configured, for example, only after the spacer element 20 is manufactured and / or provided in the stacking structure 10. It is also feasible to manufacture the spacer element 20 by plastically modifying the frame seal 15, respectively. In this case, the process fluid seal 16 is also configured only after the spacer element 20 is manufactured or provided in the stacking structure 10. It is also feasible to insert the spacer element 20 as an insertion component between two frame sealing layers. In this case, the process fluid seal 16 is also configured only after the spacer element 20 is manufactured in the stacking structure 10.

[0064] In addition to the embodiments shown, the invention also allows other basic configurations. That is, the invention should not be considered to be limited to the embodiments explained with reference to the drawings. Thus, the spacer element 20 can be configured as an integrated and / or integral component of the frame seal 15. In addition, the spacer element 20 can also be molded into one or more individual layers of the corresponding frame seal 15 by a thermal process, so that a uniform transition is achieved between the spacer element 20 and the frame seal 15.

Claims

1. A stack structure (10) for an electrochemical energy converter (80), comprising: - bipolar plates (11), - a membrane electrode unit (12), a process fluid guiding structure (13) for guiding the process fluid in a stacking direction (14), - a frame seal (15) which is fastened to the membrane electrode unit (12) in each case in the edge region of the membrane electrode unit (12), wherein: The bipolar plate (11) and the frame seal (15) are arranged one on top of the other in the stacking direction (14), - a process fluid seal (16) for sealing an edge region of the process fluid guiding structure (13), wherein the process fluid seal (16) respectively comprises an inner sealing section (18), which is positioned between the process fluid guiding structure (13) and the membrane electrode unit (12) as viewed in a transverse direction (19), the transverse direction being orthogonal to the stacking direction (14) and extending from the process fluid seal (16) in the direction of the membrane electrode unit (12), - an edge seal (17) for sealing an edge region of the frame seal (15) and / or an edge region of the bipolar plate (11), It is characterized in that - It also has a spacing element (20), which is respectively positioned and / or configured between two inner sealing sections (18) in the stacking direction (14) and has a through-opening (21) for guiding the process fluid from the process fluid guiding structure (13) to the corresponding membrane electrode unit (12) in the transverse direction (19).

2. The stacking structure (10) according to claim 1, It is characterized in that The frame seals (15) each have two frame seal layers, wherein a spacer element (20) is positioned between the two frame seal layers (15) in the stacking direction (14).

3. The stacked structure (10) according to any one of the preceding claims, It is characterized in that The spacer elements (20) are respectively positioned directly between the frame seal (15) and the inner sealing section (18) in the stacking direction (14).

4. The stacked structure (10) according to any one of the preceding claims, It is characterized in that The spacer elements ( 20 ) are each designed as an integrated and / or monolithic component of the frame seal ( 15 ).

5. The stacked structure (10) according to any one of the preceding claims, It is characterized in that The spacing element (20) has a supporting structure (22) for a supporting function in the stacking direction (14), wherein the supporting structure (22) forms at least two through-hole channels extending parallel to one another in the through-hole (21).

6. The stacked structure (10) according to any one of the preceding claims, It is characterized in that The bipolar plates (11) are welded to one another by means of at least one weld seam (34), wherein the at least one weld seam (34) is formed in the stacking direction (14) between two process fluid seals (16) and / or between two inner sealing sections (18) of the process fluid seals (16).

7. A method for producing a stacked structure (10) of an electrochemical energy converter (80), comprising the following steps: - providing a bipolar plate (11), - providing a membrane electrode unit (12), - providing a process fluid guiding structure (13) for guiding the process fluid in a stacking direction (14), - providing a frame seal (15) which is fastened to the membrane electrode unit (12) in the edge region of the membrane electrode unit (12), wherein: The bipolar plate (11) and the frame sealing portion (15) are arranged one on top of the other along the stacking direction (14). - providing a process fluid seal (16) for sealing an edge region of the process fluid guiding structure (13), wherein the process fluid seal (16) respectively comprises an inner sealing section (18), which is positioned between the process fluid guiding structure (13) and the membrane electrode unit (12) as viewed in a transverse direction (19), the transverse direction being orthogonal to the stacking direction (14) and extending from the process fluid seal (16) in the direction of the membrane electrode unit (12), - providing an edge seal (17) for sealing an edge region of the frame seal (15) and / or an edge region of the bipolar plate (11), It is characterized in that - positioning and / or configuring a spacing element (20) between two inner sealing sections (18) in the stacking direction (14) to form a through-opening (21), which is configured to guide a process fluid from the process fluid guiding structure (13) to the corresponding membrane electrode unit (12) in the transverse direction (19).

8. The method according to claim 7, It is characterized in that The spacer elements (20) are each injected onto the frame seal (15) as an injection-molded component.

9. The method according to any one of claims 7 to 8, It is characterized in that The spacer elements (20) are each produced by plastic deformation of the frame seal (15).

10. The method according to any one of claims 7 to 9, It is characterized in that The frame sealing parts (15) each have two frame sealing layers, and the spacer element (20) is inserted between the two frame sealing layers as an insert component.

Images