Manufacture of cell frames, in particular anode and / or cathode frames

Abstract

The invention relates to a method for producing cell frames (10), in particular single-part or multi-part anode frames (12) and / or single-part or multi-part cathode frames (14) for individual cells (16), arranged within a stack structure (18) of an electrolyzer (20) or a fuel cell (20), wherein the following method steps are carried out: a) providing blanks (22) made of thermoplastic organic sheets (24), b) producing a single-part or multi-part anode frame (12) and / or a single-part or multi-part cathode frame (14) made of thermoplastic organic sheets (24) in a pressing device (26), and c) applying at least one sealing contour (28, 44, 48).Furthermore, the invention relates to a cell frame (10), in particular a single-part or multi-part anode and / or a single-part or multi-part cathode frame (12, 14), and to the use of the method for producing single-part or multi-part anode and / or single-part or multi-part cathode frames (12, 14).

Description

Technical area

[0001] The invention relates to a method for producing cell frames, in particular single- or multi-part anode frames and / or single- or multi-part cathode frames for individual cells, arranged within a stacked structure of an electrolyzer or a fuel cell. Furthermore, the invention relates to a cell frame, in particular a single- or multi-part anode frame and / or a single- or multi-part cathode frame, and to the use of the method for producing single- or multi-part anode frames and / or single- or multi-part cathode frames for individual cells of an electrolyzer or a fuel cell. State of the art

[0002] EP 1 506 585 B1 relates to carbon fiber reinforced bipolar plastic plates with continuous electrical connection paths.

[0003] KR 2016 0033269 and US 7 201 988) refer to bipolar plates of fuel cells.

[0004] Thermoplastic organic sheets are recyclable, directly formable, stiff, strong, and lightweight materials. Thermoplastic composite sheets, or organic sheets, offer a wide range of applications in numerous industries. Organic sheets are high-performance continuous fiber-reinforced composite materials made of carbon or glass fiber fabric embedded in a thermoplastic matrix. Their excellent mechanical properties at low density enable weight savings of up to 60% compared to metallic materials. The multilayer, fully impregnated, and consolidated organic sheets are manufactured on a double-belt press, for example, from prepreg or semi-prepreg material. The components used can be individually adapted and customized to the specific application.

[0005] Organic sheets generally consist of several layers of thermoplastic prepreg or semi-prepreg material, which can be stacked and then pressed into a sheet with a thickness of up to 5 mm. The organic sheets can also be manufactured according to individual specifications regarding fiber orientation or layer thickness. In addition to the standard materials, special blends and compounds can be added during compounding, and all matrix and fiber combinations and fiber architectures can be individually tailored to the specific application. The selection of matrix materials used is extremely diverse: The matrix materials can range from engineering polymers, such as polyamides, to high-performance plastics, such as PEI, PEEK, and PEKK. High-quality materials such as polycarbonates and SAN are also available for visible applications.

[0006] The organic sheets are supplied as standard sheets with a width of 1.2 m. The length of the sheets can be customized depending on the application.

[0007] Organic sheets, thanks to their advantageous properties, are suitable for numerous applications. Due to the recyclability of the materials used, organic sheets can meet new requirements for sustainable design. In rapid processes such as thermoforming and overmolding, organic sheets can be used to produce cost-effective components in large quantities and with high optical quality. In thermoforming, an organic sheet is heated by radiant heaters to above the melting point of the polymer used and then formed into a component using special tools. Thermoforming offers many advantages: Significant time savings are achieved, as thermoforming takes only a few seconds to a maximum of a few minutes. A high degree of automation is possible, ensuring consistent quality even with high-volume production. Furthermore, the material used is recyclable, thus avoiding high waste. Direct formability to the final component is possible through a single-step process.

[0008] Thermoforming can be used for organic sheets with a thickness of up to 5 mm.

[0009] Organic sheets can also be further processed using the overmolding process. In this process, the thermoplastic composite laminate is first thermoformed and then overmolded, for example, using an injection molding process. Overmolding is particularly suitable for the production of parts with complex structures and enables outstanding structural rigidity with low weight, offers a high degree of functional integration, and is easy to automate and suitable for use in large-scale production.

[0010] Organic sheets can be used for all thermoformed parts or for the simple production of thicker parts. The areas of application are diverse – thanks to their advantageous mechanical, thermal, and chemical properties, organic sheets made from thermoplastic composites can be used in many applications. Disclosure of the invention

[0011] According to the invention, a method for producing cell frames, in particular single- or multi-part anode frames and / or single- or multi-part cathode frames for individual cells, arranged within a stack structure of an electrolyzer or a fuel cell, is proposed, wherein the following method steps are carried out: a) Providing blanks made of thermoplastic organic sheets, b) producing a single- or multi-part anode frame and / or a single- or multi-part cathode frame from thermoplastic organo sheets in a pressing device and c) Applying at least one sealing contour.

[0012] The process according to the invention allows previously used anode and cathode frames, which are made of a composite of metal and plastic, to be replaced by anode and cathode frame designs made of thermoplastic organic sheets. This offers a significant weight advantage.

[0013] In an advantageous development of the method proposed according to the invention, thermoplastic organic sheets are selected from a group of materials containing glass, aramid or carbon fibers.

[0014] In the method proposed according to the invention, the single- or multi-part anode frames and / or single- or multi-part cathode frames produced according to process step b) are advantageously provided with openings forming media channels. This advantageously ensures that, when the single- or multi-part anode frames and the single- or multi-part cathode frames are arranged in a stacked configuration, media channels for supplying the individual cells of the stacked structure are provided from the aligned openings.

[0015] In an advantageous embodiment of the method proposed according to the invention, groups of openings arranged on opposite sides of single-part or multi-part anode frames and / or single-part or multi-part cathode frames are surrounded by a circumferential sealing structure.

[0016] In a further development of the method proposed according to the invention, groups of openings connected to channels on opposite sides of single-part or multi-part anode frames and / or single-part or multi-part cathode frames are provided with a further circumferential seal.

[0017] Furthermore, the invention relates to a cell frame, in particular single-part or multi-part anode frames or single-part or multi-part cathode frames of individual cells, within a stack structure of an electrolyzer or a fuel cell, manufactured according to the method described above, wherein the single-part or multi-part anode frame and / or the single-part or multi-part cathode frame are made of a thermoplastic organic material.

[0018] Furthermore, the invention relates to the use of the method for producing single- or multi-part anode and / or single- or multi-part cathode frames of individual cells of an electrolyzer or a fuel cell. Advantages of the invention

[0019] The solution proposed by the invention allows previously used cell frames, in particular single- or multi-part anode frames and single- or multi-part cathode frames made from a composite of metal and plastic, to be replaced with those made from a thermoplastic organic sheet. This results in a significant weight advantage for a fully assembled stacked structure, both for an electrolyzer and for a fuel cell used in mobile applications. Due to the relatively high pressure level, it is not possible to manufacture a cell frame, neither a single- or multi-part anode frame nor a single- or multi-part cathode frame, from a pure plastic material. Metallic materials used previously can be problematic, particularly when only small material thicknesses are planned within the single- or multi-part anode frame or single- or multi-part cathode frame to be manufactured.In the solution proposed by the invention, a thermoplastic matrix material can be used for the thermoplastic organic sheets, which is individually tailored to the application and the load. The fiber material used can be selected depending on the application, with this being chosen in particular from the group of glass fibers, aramid fibers, and carbon fibers.

[0020] The use of thermoplastic organic sheets ensures chemical resistance. Furthermore, large quantities can be produced flawlessly in continuous production processes.

[0021] Furthermore, it is particularly noteworthy that the use of thermoplastic organic sheets eliminates the need for metallic components. This, in turn, means that there is no chemical attack and, especially over the lifetime and operating period, no corrosion phenomena can occur. Short description of the drawings

[0022] Embodiments of the invention are explained in more detail with reference to the drawings and the following description.

[0023] They show: Fig. 1 a perspective view of a stack structure, for example a fuel cell, Fig. 2 a view of an electrolyzer, Fig. 3 a schematic representation of a pressing device, Fig. 4 a deformation with formation of a sealing contour in a thermoplastic organic sheet, Fig. 5.1-5.3 different characteristics and deformations in blanks of the thermoplastic organo sheet material, Fig. 6.1 a plan view of a single- or multi-part anode frame of a single cell, made of a thermoplastic organo sheet, Fig. 6.2 a plan view of a single- or multi-part cathode frame of a single cell, made of a thermoplastic organo sheet and Fig. 7.1, 7.2 one- and two-part versions of anode and cathode frames. Embodiments of the invention

[0024] In the following description of the embodiments of the invention, identical or similar elements are designated by the same reference numerals, whereby a repeated description of these elements is omitted in individual cases. The figures only schematically illustrate the subject matter of the invention.

[0025] Fig. 1 shows a perspective view of a stacked structure 18, for example for a fuel cell 20. The stacked structure 18 comprises a number of individual cells 16 arranged one above the other, which are not shown in detail here. The stacked structure 18 according to the illustration in Fig. 1 has openings 32 on its upper end face, which are arranged in rows next to one another and, in the stacked configuration of the stack structure 18, form small channels 46 for media flowing through the stack structure 18.

[0026] Fig. 2 shows the view of an electrolyzer 20, which essentially comprises the stack structure 18 as shown in Fig. 1. The stack structure 18 comprises a number of individual cells 16 stacked vertically one above the other, which are each clamped against one another in a sealing manner via end plates and clamping screws and form the configuration of an electrolyzer or a fuel cell 20.

[0027] Fig. 3 shows an example of a pressing device 26 which is suitable for pressing thermoplastic organic sheets 24 from, for example, the Fig. 5.1, 5.2 and 5.3 to deform and configure the blanks 22 shown for later applications.

[0028] While in Fig. 3 schematically shows a pressing device 26, Fig. 4 a thermoplastic organic sheet 24, which is provided, for example, with a U-shaped deformation 30 to form a sealing contour 28. Of course, the deformations 30 can also be formed in other geometries depending on the intended use.

[0029] The Fig. 5.1, 5.2 and 5.3 show individual blanks 22 of thermoplastic organic sheets 24. These can be, as in Fig. 5.2, are arranged essentially flat. They can be arranged as shown in Fig. 5.1, but can also be provided with deformations 30.

[0030] Fig. 6.1 shows a plan view of a single- or multi-part anode frame 12 of a single cell 16, which can be arranged within the stack structure 18 of the electrolyzer or the fuel cell 20.

[0031] From the top view according to Fig. 6.1 shows a cell frame 10 in the form of a single- or multi-part anode frame 12. The single- or multi-part anode frame 12 is part of the individual cell 16 of the stack structure 18 of the electrolyzer or the fuel cell 20. The cell frame 10 in the form of the single- or multi-part anode frame 12 as shown in Fig. 6.1 is manufactured from a blank 22 of the thermoplastic organic sheet 24. For this purpose, the pressing device 26 is advantageously used, which is shown schematically in Fig. 3. The individual blanks 22 can, as shown in the Fig. 5.2 and 5.3, are present or according to the Fig. 5.1 or 4 have deformations 30 or are already available as preformed blanks 22.

[0032] Furthermore, the Fig. 6.1 shown plan view of the cell frame 10, in particular the single-part or multi-part anode frame 12, that on the top side of the single-part or multi-part anode frame 12 according to Fig. 6.1 at least one sealing contour 28 runs.

[0033] From the top view according to Fig. 6.1 shows that the here essentially square shaped one- or multi-part anode frame 12 has four mutually perpendicular sides 36, 38, 40, 42. Along the said sides 36, 38, 40, 42, in the thermoplastic organo sheet 24 of the one- or multi-part anode frame 12, as shown in Fig. 6.1 individual openings 32 are shown. These can, for example, be designed as circular holes, as shown here. If the individual single- or multi-part anode frames 12 are connected with single- or multi-part cathode frames 14, as shown in Fig. 6.2 are stacked one on top of the other in the vertical direction within the stack structure 18, media channels 34 are formed due to the aligned openings 32. Media such as water, gaseous hydrogen, air and the like are transported via the media channels 34 in the stack structure 18.

[0034] Fig. Figure 6.1 shows that on the opposite sides 36 and 40, the individual openings 32 are enclosed in groups by a first circumferential seal 44. The openings 32 opposite each other on the sides 38 and 42, each of which is connected to a channel system 46, are enclosed by a further circumferential seal 48 that continuously surrounds them.

[0035] Fig. 6.2 shows a single or multi-part cathode frame 14, which is essentially identical to the one shown in Fig. 6.1 shown single or multi-part anode frame 12. The Fig. The single- or multi-part cathode frame 14 shown in Figure 6.2 is made of a thermoplastic organic sheet 24 and is significantly lighter than previously used components for cell frames 10, which are made of a plastic-metal composite. Furthermore, this component is resistant to corrosion.

[0036] While in the illustration according to Fig. 6.1 shows a single or multi-part anode frame 12 through whose small channels 46 water flows, Fig. 6.2 a single- or multi-part cathode frame 14, through whose small channels 46 gaseous hydrogen flows. The small channels 46 are each arranged at an angle of 90° to one another. Due to the uniform distribution of the small channels 46, which form a coherent channel system, a uniform surface pressure is established in the stack structure 18, thus ensuring external sealing. The seals 44, 48 or the sealing contours are adhesively applied in sealing contours 48 in the respective single- or multi-part anode or cathode frames 12, 14. The seals 44, 48, which are manufactured, for example, using an injection molding process, can be glued on. The seals 44, 48 used are made of a sealing material, which can preferably be an elastomer, such as rubber or silicone or similar.The actual seals 44, 48 are applied after the single- or multi-part anode and cathode frames 12, 14 have cured. The seals 44, 48 can be manufactured using injection molding as insert seals with positioning to prevent them from falling out. However, seals applied by handling robots can also be used.

[0037] According to the representations Fig. 7.1 and 7.2 show individual cells 16, which are either formed with, for example, one-piece anode or cathode frames 12, 14 or - as in Fig. 7.2 - can have a two-part anode or cathode frame 12, 14. While in the Fig. 7.1 a one-piece anode and / or cathode frame 12, 14 is shown, which represents a fusion of a one-piece or multi-piece anode frame 12 with a one-piece or multi-piece cathode frame 14, shows Fig. 7.2 each have a one-piece anode or cathode frame 12, 14.

[0038] From the representation according to Fig. 7.2 shows a one-piece anode or cathode frame 12, 14, in which a CCM membrane 62 has a porous transport layer 60 (PTL) on its upper side and is provided with a gas diffusion layer 58 (GDL) on its lower side. This applies to both the Fig. 7.1 and 7.2. In contrast to the design variant according to Fig. 7.1 passes through the CCM membrane 62 according to the design variant in Fig. 7.2 the entire length of the individual cell 16. Reference numeral 46 designates small channels of a channel system for media transport, not shown in detail here.

[0039] From a comparison of the Fig. 7.1 and 7.2 it is clear that in the Fig. 7.1 shown embodiment variant, seals 66 are provided in a groove 64 and in comparison to the embodiment variant according to Fig. 7.2 at least two seals 66 and two grooves 64, which are provided opposite each other in the area of ​​the membrane 62, can be saved. In the embodiment according to Fig. 7.1, the seal 66, also embedded in a circumferential groove 64, for example, runs only along the edge.

[0040] The invention is not limited to the embodiments described here and the aspects highlighted therein. Rather, numerous modifications are possible within the scope of the claims, which are within the scope of one skilled in the art. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] EP 1 506 585 B1

[0002] KR 2016 0033269

[0003] US 7 201 988

[0003]

Claims

[1] Method for producing cell frames (10), in particular single-part or multi-part anode frames (12) and / or single-part or multi-part cathode frames (14) for individual cells (16), arranged within a stack structure (18) of an electrolyzer or a fuel cell (20), comprising the following method steps: a) providing blanks (22) made of thermoplastic organic sheets (24), b) producing a single-part or multi-part anode frame (12) and / or a single-part or multi-part cathode frame (14) from thermoplastic organic sheets (24) in a pressing device (26), c) applying at least one sealing contour (28, 44, 48). [2] Method according to claim 1, characterized by that thermoplastic organic sheets (24) are selected from the group of glass, aramid or carbon fibres. [3] Method according to claims 1 and 2, characterized bythat the single-part or multi-part anode frames (12) and / or single-part or multi-part cathode frames (14) produced according to process step b) are each provided with openings (32) forming media channels (34). [4] Method according to claims 1 to 3, characterized by that groups (50, 52) of openings (32) arranged on opposite sides (36, 40) of the single-part or multi-part anode frames (12) and / or the single-part or multi-part cathode frames (14) are enclosed by a circumferential seal (44). [5] Method according to claims 1 to 4, characterized by that openings (32) communicating with small channels (46) on opposite sides (38, 42) of the single-part or multi-part anode frames (12) and / or the single-part or multi-part cathode frames (14) are provided with a further circumferential seal (48). [6] Cell frame (10), in particular a single-part or multi-part anode and / or single-part or multi-part cathode frame (12, 14) of a single cell (16) within a stack structure (18) of an electrolyzer or a fuel cell (20), manufactured according to the method according to one of claims 1 to 5, characterized by that the single-part or multi-part anode frame (12) and / or the single-part or multi-part cathode frame (14) are made of a thermoplastic organic sheet (24). [7] Use of the method according to one of claims 1 to 5 for producing single-part or multi-part anode and / or single-part or multi-part cathode frames (12, 14) of individual cells (16) of an electrolyzer or a fuel cell (20).

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