Method for producing components for an electrochemical cell unit

Abstract

The invention relates to a method for producing components (5, 6, 7, 8, 9, 10, 30, 51, 64, 65) for an electrochemical cell unit (53) for converting electrochemical energy into electrical energy as a fuel cell unit (1) and / or for converting electrical energy into electrochemical energy as an electrolytic cell unit (49), comprising the steps of: providing blanks (82), introducing the blanks (82) into first stamping tools (86) and / or second stamping tools (87), carrying out a change process in the form of deformation of the blanks (82) to create the components (5, 6, 7, 8, 9, 10, 30, 51, 64, 65) while the blanks (82) are disposed between the first and second stamping tools (86, 87), removing the shaped components (5, 6, 7, 8, 9, 10, 30, 51, 64, 65) from the first stamping tools (86) and from the second stamping tools (87), wherein the change process in the form of deformation of the blanks (82) to create the components (5, 6, 7, 8, 9, 10, 30, 51, 64, 65) while the blanks (82) are disposed between the first and second stamping tools (86, 87) is carried out by means of at least one press (75).

Description

[0001] Description

[0002] title

[0003] Process for the production of components for an electrochemical

[0004] cell unit

[0005] The present invention relates to a method for producing components for an electrochemical cell unit according to the preamble of claim 1 and a method for producing an electrochemical cell unit according to the preamble of claim 15.

[0006] State of the art

[0007] Fuel cell units, as galvanic cells, convert continuously supplied fuel and oxidant into electrical energy and water through redox reactions at an anode and cathode. Fuel cells are used in a wide variety of stationary and mobile applications, for example, in homes without a power grid connection or in motor vehicles, rail transport, aviation, aerospace, and shipping.

[0008] In fuel cell units, a large number of fuel cells are arranged in a fuel cell stack. Within each fuel cell, there is a gas space for the oxidant, i.e., a flow space for the passage of oxidant, such as ambient air with oxygen. The gas space for the oxidant is formed by channels on the bipolar plate and by a gas diffusion layer for a cathode. The channels are thus formed by a corresponding channel structure of a bipolar plate, and the oxidant, namely oxygen, flows through the gas diffusion layer to the cathodes of the fuel cells. A gas space for fuel is provided in a similar manner.

[0009] Electrolysis cell units consisting of stacked electrolysis cells, similar to fuel cell units, are used, for example, for the electrolytic production of hydrogen and oxygen from water. Fuel cell units are also known that can be operated as reversible fuel cell units and thus as electrolysis cell units.

[0010] Fuel cell units and electrolysis cell units form electrochemical cell units. Fuel cells and electrolysis cells form electrochemical cells.

[0011] For the manufacture and assembly of electrochemical cells, especially fuel cells, it is necessary to arrange the fuel cell components in a flush stack. The disc-shaped components of the fuel cells are proton exchange membranes, anodes, cathodes, gas diffusion layers, and bipolar plates. An essential component of the stack are the electrically conductive bipolar plates. These function as current collectors, for water drainage, and for conducting reaction gases as process fluids, as well as liquid or gaseous coolants as process fluids, through flow spaces, particularly channels or channel structures. The bipolar plates rest on contact surfaces on the gas diffusion layers. The bipolar plates are generally formed from two or three plates.During the production of bipolar plates, a first and second plate are placed on top of each other, and then the plates are bonded together to form connecting seams. These connecting seams not only serve to bond the plates together in a bonded and electrically conductive manner, but also serve to fluidically seal coolant channels formed between each two plates.

[0012] To manufacture the bipolar plates, essentially flat or planar first and second plates are first produced from a composite material with plastic and an electrically conductive filler. The first and second plates are manufactured by subjecting blanks to a mechanical and thermal modification process in cavities between first and second stamping tools. The mechanical and thermal modification process is carried out in a double-belt press between a first and second endless belt of the double-belt press. After passing through the double-belt press, the stamping tools are transported separately and discontinuously from an end area of ​​the double-belt press back to a start area of ​​the double-belt press. This is complex and expensive because no series production is carried out in an overall continuous manufacturing process.

[0013] DE 102021 104 564 A1 shows a method for the continuous production of strip-shaped plate material which can be divided into bipolar plates or blanks for bipolar plates and which is made of plastic mixed with electrically conductive particles, wherein a powder comprising the particles and the plastic is scattered to form a preform and wherein the preform is pressed hot between a lower belt and an upper belt of a double belt press to form the plate material, wherein the particles and the plastic are compounded to form a compound and the compound is ground to form the powder.

[0014] DE 102020 006 943 A1 discloses a manufacturing method for components of a fuel cell stack from a mixture which comprises at least one plastic and at least one electrically conductive filler, by means of a double belt press, wherein a web-shaped uncured or not fully cured blank from the mixture is fed to an isochoric double belt press with individual segments, wherein each of the individual segments has a shaping structure for shaping the blank into the component as it passes through the double belt press, wherein the individual segments on the two belts of the double belt press are positioned relative to one another during the pressing process via corresponding locking elements.

[0015] CN 114725417 A shows a method for producing bipolar plates with rollers for shaping the bipolar plates from a raw material.

[0016] Disclosure of the invention

[0017] Advantages of the invention Method according to the invention for producing components for an electrochemical cell unit for converting electrochemical energy into electrical energy as a fuel cell unit and / or for converting electrical energy into electrochemical energy as an electrolysis cell unit with the steps: providing blanks, introducing the blanks into first stamping tools and / or second stamping tools, carrying out a change process as deforming the blanks to form the components while the blanks are arranged between the first and second stamping tools, removing the formed components from the first stamping tools and from the second stamping tools, wherein the change process as deforming the blanks to form the components while the blanks are arranged between the first and second stamping tools is carried out with at least one press.

[0018] In an additional embodiment, the transformation process is carried out by deforming the blanks into the components while the blanks are arranged between the first and second stamping tools sequentially using a plurality of presses arranged in series in a press system, such that at least one blank undergoes the transformation process sequentially between each identical first and second stamping tool in the plurality of presses. Preferably, no compressive force is applied from a press to the first and second stamping tools while the first and second stamping tools are moved from one press to another.The method is thus preferably carried out during active intervals while the blanks are arranged between the first and second stamping tools in the presses and a compressive force is applied by the presses to the first and second stamping tools, and during inactive mechanical intervals while the first and second stamping tools are moved from one press to another, no compressive force is applied by a press to the first and second stamping tools, so that the press system forms an interval press system. In a further variant, consolidation as a reduction in the volume of the blanks is carried out in at least one of the presses arranged in series.Consolidation, i.e., the reduction of the volume of the blanks, is thus carried out in separate stages in a separate press, particularly as a mechanical processing station. Arranging the presses in series preferably refers to the chronological sequence of the change process and not to the geometric arrangement of the presses. Preferably, however, the presses are arranged geometrically in a row.

[0019] In an additional embodiment, the transformation process of the blanks into components is carried out by thermally treating the blanks.

[0020] Preferably, the blanks are thermally treated while one blank is arranged in a cavity between the first and second stamping tools and a compressive force is applied to the first and second stamping tools by a press.

[0021] In an additional variant, the blanks are thermally treated by heating them.

[0022] In a supplementary embodiment, the blanks are thermally treated by cooling the blanks.

[0023] In a further embodiment, the blanks are first heated and then cooled, in particular in different presses.

[0024] Expediently, the execution of a change process as deformation of the blanks into the components while the blanks are arranged between the first and second stamping tools is carried out substantially isobarically, in particular with a deviation of less than 30%, 20% or 10%.

[0025] In a further variant, the essentially isobaric change process of the blanks, in particular with a deviation of less than 30%, 20%, or 10%, is carried out in a separate press. An essentially isobaric change of state of the blanks is preferably a change process in which, after an initial phase of increasing the pressure and before a final phase of reducing the pressure applied to the blanks, a substantially constant pressure is applied to the blanks, and this constant pressure differs by less than 30%, 20%, or 10%.

[0026] In a supplementary embodiment, during the execution of the modification process, i.e., deformation of the blanks into the components while the blanks are arranged between the first and second stamping tools, excess composite material is drained from a respective cavity between the first and second stamping tools through a channel, in particular a plunge edge. If the volume of the blanks is greater than the minimum volume of the cavity on the stamping tool and sufficient consolidation cannot be achieved by reducing the volume of the blanks, the excess composite material of the blank is drained from the cavity into the environment through the channel, in particular the plunge edge.

[0027] In a supplementary embodiment, the blanks are made of a composite material comprising a mixture of a plastic, in particular thermoplastic and / or thermosetting plastic, and at least one electrically conductive filler.

[0028] In an additional variant, the method is carried out using presses as hydraulic pressing devices with at least one hydraulic piston and at least one hydraulic cylinder, by applying a hydrostatic pressure force of the hydraulic fluid to the at least one hydraulic piston. Preferably, each press comprises an upper and lower pressure plate. In a further variant, a pressure plate of the press is movable; in particular, an upper pressure plate of a hydraulic pressing device is movable by means of a hydraulic piston.

[0029] In an additional embodiment, bipolar plates are produced with the following steps: providing first plates and second plates by carrying out a method described in this patent application, stacking the first plates and the second plates on top of one another such that a first and a second plate each lie on top of one another, producing at least one connection, in particular at least one material connection, between the first and the second plate. The connection between a first and a second plate is preferably produced with connecting seams, in particular weld seams and / or adhesive seams, by means of welding and / or adhesive bonding. The first and second plates are preferably stacked flush with one another.

[0030] A method according to the invention for producing an electrochemical cell unit for converting electrochemical energy into electrical energy as a fuel cell unit and / or for converting electrical energy into electrochemical energy as an electrolysis cell unit with stacked electrochemical cells, comprising the steps of: providing layered components of the electrochemical cells, namely preferably ion exchange membranes, in particular proton exchange membranes, anodes, cathodes, preferably gas diffusion layers and bipolar plates, stacking the layered components to form electrochemical cells and a stack of the electrochemical cell unit, wherein the components, in particular bipolar plates, are provided by carrying out a method described in this patent application.

[0031] In a further embodiment, the change process of deforming and thermally treating, in particular heating, is carried out simultaneously for each blank, in particular during the arrangement in each press.

[0032] In a supplementary embodiment, the return transport of the embossing tools from an end region to a start region is carried out with a transport system, in particular a conveyor belt, preferably an endless conveyor belt, and / or an industrial robot.

[0033] In a further embodiment, the embossing tools are transported from the end region to the start region and from the start region to the end region using at least one conveyor belt, in particular at least one endless and / or closed conveyor belt. When the embossing tools are transported from the start region to the end region, the embossing tools are transported from one press to another press using the at least one conveyor belt. The pressing tools are preferably attached to the conveyor belt. The conveyor belt is preferably formed from a flexible belt and / or chain links.

[0034] In a supplementary variant, the first embossing tools are attached to a first conveyor belt and the second embossing tools are attached to a second conveyor belt.

[0035] In an additional embodiment, the at least one conveyor belt with the stamping tools attached thereto is moved discontinuously, ie during the transport of the stamping tools from one press to another press, the at least one conveyor belt is moved and during the change process in the presses, in particular the application of a compressive force to the blanks, the at least one conveyor belt is not moved and / or is stationary and / or is fixed while the first and second stamping tools are subjected to a compressive force from the presses.

[0036] In a further embodiment, the magnitude of the compressive force and / or surface pressure and / or compressive stress with which the first and second stamping tools in each press are subjected is controlled and / or regulated.

[0037] Preferably, in the hydraulic pressing device, the pressure of the hydraulic fluid is controlled and / or regulated and / or is controllable and / or adjustable in order to carry out a substantially isobaric change process.

[0038] In a further variant, the magnitude of the compressive force and / or surface pressure and / or compressive stress with which the first and second stamping tools are acted upon in each hydraulic pressing device is controlled and / or regulated by controlling and / or regulating the pressure of the hydraulic fluid.

[0039] In an additional variant, the process of transforming the blanks into components is carried out as thermally treating the blanks by heating them to a temperature greater than 70°C, 100°C, 200°C, 300°C or 400°C, so that the blanks harden, in particular during and / or after cooling.

[0040] In an additional variant, the transformation process of the blanks into components is carried out as the thermal treatment of the blanks by means of cooling by cooling the blanks to a temperature lower than 200°C, 100°C or 70°C.

[0041] In a further embodiment, the blanks are made of a composite material consisting of a mixture of a plastic, in particular a thermoplastic and / or thermosetting plastic, and at least one electrically conductive filler. The electrically conductive filler is preferably formed from particles of metal and / or carbon, in particular graphite.

[0042] In a further embodiment, the blanks are heated and / or cooled, preferably by heat flow and / or heat conduction and / or heat radiation and / or induction, before and / or during the transformation process of forming the blanks into the components while the blanks are arranged between the first and second stamping tools. The blanks are heated, for example, with a heat radiator and / or by passing a heat transfer fluid, in particular through at least one pressure plate of at least one press.

[0043] In an additional variant, components or parts for a redox flow battery and / or anodes and / or cathodes for the electrochemical cell unit are produced using the process described in this patent application.

[0044] In particular, the first stamping tools and the second stamping tools are cleaned after the components have been removed from the first stamping tools and the second stamping tools and during the return transport from an end region to a start region of a press system. In a further embodiment, an anti-adhesion agent is applied, in particular sprayed, to the first stamping tools and the second stamping tools after the components have been removed from the first stamping tools and the second stamping tools during the return transport from the end region to the start region, in particular with the transport system, in particular a conveyor belt and / or industrial robot.

[0045] Preferably, the transport system is formed by at least one, preferably endless, conveyor belt and / or at least one industrial robot and / or at least one roller conveyor.

[0046] In a further embodiment, the first stamping tools and the second stamping tools are cleaned after removing the components from the first stamping tools and the second stamping tools during the return transport from the end region to the start region of the manufacturing system.

[0047] In a supplementary embodiment, the deformation of the blanks into the components is carried out while the blanks are arranged between the first and second stamping tools in a press each, in particular in at least one thermal processing station, by applying a compressive force and / or surface pressure and / or compressive stress to the blanks for deformation by the stamping tools, in particular first and second stamping tools, wherein preferably the magnitude of the compressive force and / or surface pressure and / or compressive stress is controlled and / or regulated and / or is controllable and / or adjustable.

[0048] In a further embodiment, the provision of blanks is carried out by means of extrusion and / or calendering.

[0049] In a further embodiment, at least 90% of the bipolar plates, in particular all bipolar plates, are made available to the electrochemical cell unit by carrying out a method described in this patent application.

[0050] In a further embodiment, each bipolar plate is formed from two or three plates, and the two or three plates are bonded to one another using the method described in this patent application, using an adhesive bond and / or a welded joint. The welded joint between the at least two plates is created, for example, by locally heating the locally linearly heated material of the at least two plates along a connecting seam to be created as a weld seam, followed by a material-to-material bonding and subsequent hardening.

[0051] In a further variant, the electrochemical cell unit comprises at least 50, 100, 200 or 400 stacked electrochemical cells.

[0052] In a supplementary embodiment, fluid openings are produced in the blanks by means of punching and / or bending with the first and second stamping tools.

[0053] In a further embodiment, at least one, two or three positioning elements are formed on each first and / or second embossing tool.

[0054] In a further embodiment, at least one, two or three sealing elements are formed on a first and / or second stamping tool.

[0055] In a supplementary variant, during the reduction of the distance between a first and a second embossing tool, an alignment of the first and second embossing tools to each other is carried out due to a positive contact between positioning elements.

[0056] In a supplementary variant, during the reduction of the distance between a first and a second stamping tool, a sealing of at least one cavity between the first and the second stamping tool is carried out due to a positive contact between sealing elements.

[0057] The invention further comprises a computer program having program code means stored on a computer-readable data carrier for carrying out a method described in this patent application when the computer program is executed on a computer or a corresponding computing unit.

[0058] The invention also includes a computer program product with program code stored on a computer-readable data carrier for implementing a method described in this patent application when the computer program is executed on a computer or a corresponding computing unit. The computer-readable data carrier is, for example, a hard disk drive, in particular an HDD or SSD, a USB stick, a DVD (Digital Versatile Disc), and / or a CD (Compact Disc).

[0059] Suitable components are electrochemical cells, in particular fuel cells and / or electrolysis cells, preferably ion exchange membranes, in particular proton exchange membranes, anodes, cathodes, preferably gas diffusion layers and bipolar plates, in particular separator plates.

[0060] The fuel cells and / or electrolysis cells are expediently designed to be substantially flat and / or disc-shaped.

[0061] Preferably, the fuel cell unit is a PEM fuel cell unit with PEM fuel cells or an SOFC fuel cell unit with SOFC fuel cells or an alkaline fuel cell (AFC) or a solid oxide fuel cell (SOFC).

[0062] Preferably, the electrolysis cell unit is a PEM electrolyzer with an acidic electrolyte or an alkaline electrolyzer or a reversible solid oxide fuel cell (SOEC).

[0063] Short description of the drawings

[0064] In the following, exemplary embodiments of the invention are described in more detail with reference to the accompanying drawings. Figure 1 shows a highly simplified exploded view of an electrochemical cell system as a fuel cell system and electrolysis cell system with components of an electrochemical cell as a fuel cell and electrolysis cell.

[0065] Fig. 2 is a perspective view of part of a fuel cell and electrolysis cell,

[0066] Fig. 3 a longitudinal section through electrochemical cells as fuel cell and electrolysis cell,

[0067] Fig. 4 is a perspective view of an electrochemical cell unit as a fuel cell unit and electrolysis cell unit as a fuel cell stack and electrolysis cell stack,

[0068] Fig. 5 is a side view of the electrochemical cell unit as a fuel cell unit and electrolysis cell unit as a fuel cell stack and electrolysis cell stack,

[0069] Fig. 6 is a perspective view of a bipolar plate,

[0070] Fig. 7 shows an enlarged longitudinal section through a fuel cell and electrolysis cell in the area of ​​an adhesive seam as a connecting seam,

[0071] Fig. 8 is a plan view of a side as a flat side of a bipolar plate,

[0072] Fig. 9 a cross section through a first and second embossing tool,

[0073] Fig. 10 shows a highly simplified longitudinal section through a manufacturing system with a press system.

[0074] Figs. 1 to 3 show the basic structure of a fuel cell 2 as a PEM fuel cell 3 (polymer electrolyte fuel cell 3). The principle of fuel cells 2 is that electrical energy or electrical current is generated by means of an electrochemical reaction. Hydrogen H2 is fed to an anode 7 as a gaseous fuel, and the anode 7 forms the negative pole. A gaseous oxidizing agent, namely air with oxygen, is fed to a cathode 8, i.e. the oxygen in the air provides the necessary gaseous oxidizing agent. Reduction (electron absorption) takes place at the cathode 8. Oxidation (electron release) takes place at the anode 7.

[0075] The redox equations of the electrochemical processes are:

[0076] Cathode:

[0077] O2+ 4 H + + 4 e- -» 2 H2O

[0078] Anode:

[0079] 2 H2-» 4 H+ + 4 e-

[0080] Total reaction equation of cathode and anode: 2 H2+ O2-» 2 H2O

[0081] The difference between the normal potentials of the electrode pairs under standard conditions as the reversible fuel cell voltage or open circuit voltage of the unloaded fuel cell 2 is 1.23 V. This theoretical voltage of 1.23 V is not achieved in practice. In the idle state and with small currents, voltages above 1.0 V can be achieved, and when operating with larger currents, voltages between 0.5 V and 1.0 V are achieved. The series connection of several fuel cells 2, in particular a fuel cell unit 1 as a fuel cell stack 1 of several stacked fuel cells 2, has a higher voltage which corresponds to the number of fuel cells 2 multiplied by the individual voltage of each fuel cell 2.

[0082] The fuel cell 2 also includes a proton exchange membrane 5 (Proton Exchange Membrane, PEM), which is arranged between the anode 7 and the cathode 8. The anode 7 and cathode 8 are layered or disc-shaped. The PEM 5 acts as an electrolyte, catalyst support, and separator for the reaction gases. The PEM 5 also acts as an electrical insulator and prevents an electrical short circuit between the anode 7 and cathode 8. Generally, 12 pm to 150 pm thick, proton-conducting films made of perfluorinated and sulfonated polymers are used. The PEM 5 conducts the protons H + and blocks ions other than protons H + essentially, so that due to the permeability of the PEM 5 for the protons H +Charge transport can occur. The PEM 5 is essentially impermeable to the reaction gases oxygen O2 and hydrogen H2, i.e., it blocks the flow of oxygen O2 and hydrogen H2 between a gas space 31 at the anode 7 containing hydrogen H2 as fuel and the gas space 32 at the cathode 8 containing air or oxygen O2 as oxidizing agent. The proton conductivity of the PEM 5 increases with increasing temperature and increasing water content.

[0083] On the two sides of the PEM 5, each facing the gas spaces 31, 32, the electrodes 7, 8 are located as the anode 7 and cathode 8. A unit comprising the PEM 5 and the electrodes 7, 8 is referred to as a membrane electrode assembly (MEA) 6. The electrodes 7, 8 are pressed onto the PEM 5. The electrodes 7, 8 are platinum-containing carbon particles bonded to PTFE (polytetrafluoroethylene), FEP (fluorinated ethylene-propylene copolymer), PFA (perfluoroalkoxy), PVDF (polyvinylidene fluoride), and / or PVA (polyvinyl alcohol) and hot-pressed into microporous carbon fiber, glass fiber, or plastic mats. A catalyst layer 30 (not shown) is normally applied to each of the electrodes 7, 8 on the side facing the gas spaces 31, 32. The catalyst layer 30 on the gas space 31 with fuel at the anode 7 comprises nanodispersed platinum-ruthenium on graphitized soot particles bound to a binder.The catalyst layer 30 in the gas space 32 with the oxidizing agent at the cathode 8 comprises nanodispersed platinum. Binders used include, for example, Nafion®, a PTFE emulsion, or polyvinyl alcohol.

[0084] In contrast, the electrodes 7, 8 are made of an ionomer, for example, Nation®, platinum-containing carbon particles, and additives. These electrodes 7, 8 with the ionomer are electrically conductive due to the carbon particles and also conduct the protons H + and additionally function as a catalyst layer 30 (Figs. 2 and 3) due to the platinum-containing carbon particles. Membrane electrode assemblies 6 with these electrodes 7, 8 comprising the ionomer form membrane electrode assemblies 6 as CCM (catalyst coated membrane).

[0085] A gas diffusion layer 9 (GDL) lies on the anode 7 and the cathode 8. The gas diffusion layer 9 on the anode 7 evenly distributes the fuel from channels 12 for fuel onto the catalyst layer 30 on the anode 7. The gas diffusion layer 9 on the cathode 8 evenly distributes the oxidant from channels 13 for oxidant onto the catalyst layer 30 on the cathode 8. The GDL 9 also draws off reaction water in the opposite direction to the flow direction of the reaction gases, i.e. in a direction from the catalyst layer 30 or electrodes 7, 8 to the channels 12, 13. Furthermore, the GDL 9 keeps the PEM 5 moist and conducts the current. The GDL 9 is constructed, for example, from a hydrophobized carbon paper as a carrier and substrate layer and a bonded carbon powder layer as a microporous layer.

[0086] A bipolar plate 10 rests on the GDL 9. The electrically conductive bipolar plate 10 serves as a current collector, for water drainage and for conducting the reaction gases as process fluids through the channel structures 29 and / or flow fields 29, and for dissipating the waste heat, which occurs particularly during the exothermic electrochemical reaction at the cathode 8. To dissipate the waste heat, channels 14 are incorporated into the bipolar plate 10 as a channel structure 29 for conducting a liquid or gaseous coolant as a process fluid. The channel structure 29 at the gas space 31 for fuel is formed by channels 12. The channel structure 29 at the gas space 32 for oxidizing agent is formed by channels 13. Composite materials are used as the material for the bipolar plates 10.

[0087] In a fuel cell unit 1 and / or a fuel cell stack 1 and / or a fuel cell stack 1, a plurality of fuel cells 2 are arranged in an aligned stack (Figs. 4 and 5). Fig. 1 shows an exploded view of two fuel cells 2 arranged in an aligned stack. Seals 11 seal the gas spaces 31, 32 or channels 12, 13 in a fluid-tight manner. In a compressed gas reservoir 21 (Fig. 1), hydrogen H2 is stored as fuel at a pressure of, for example, 350 bar to 700 bar. From the compressed gas reservoir 21, the fuel is fed through a high-pressure line 18 to a pressure reducer 20 to reduce the pressure of the fuel in a medium-pressure line 17 from approximately 10 bar to 20 bar. From the medium-pressure line 17, the fuel is fed to an injector 19. At the injector 19, the pressure of the fuel is reduced to an injection pressure between 1 bar and 3 bar.From the injector 19, the fuel is fed to a fuel supply line 16 (Fig. 1) and from the supply line 16 to the fuel channels 12, which form the fuel channel structure 29. The fuel thereby flows through the fuel gas space 31. The fuel gas space 31 is formed by the channels 12 and the GDL 9 at the anode 7. After flowing through the channels 12, the fuel not consumed in the redox reaction at the anode 7 and, if applicable, water from a controlled humidification of the anode 7 are discharged from the fuel cells 2 through a discharge line 15.

[0088] A gas conveying device 22, for example designed as a blower 23 or a compressor 24 or a turbo compressor, conveys air from the environment as the oxidant into a supply line 25 for the oxidant. From the supply line 25, the air is supplied to the channels 13 for the oxidant, which form a channel structure 29 on the bipolar plates 10 for the oxidant, so that the oxidant flows through the gas space 32 for the oxidant. The gas space 32 for the oxidant is formed by the channels 13 and the GDL 9 at the cathode 8. After flowing through the

[0089] The oxidizing agent not consumed at the cathode 8 and the reaction water produced at the cathode 8 due to the electrochemical redox reaction are discharged from the fuel cells 2 through a discharge line 26 via channels 13 and the gas space 32 for the oxidizing agent 32. A supply line 27 serves to supply coolant into the coolant channels 14, and a discharge line 28 serves to discharge the coolant conducted through the channels 14. The supply and discharge lines 15, 16, 25, 26, 27, 28 are shown as separate lines in Fig. 1 for simplification. At the end region near the channels 12, 13, 14, aligned fluid openings 41 are formed on sealing plates 39 as an extension at the end region 40 of the superimposed bipolar plates 10 (Fig. 6) and membrane electrode assemblies 6 (not shown) in the stack as a stack of the fuel cell unit 1.The fuel cells 2 and the components of the fuel cells 2 are disk-shaped and span fictitious planes 59 aligned essentially parallel to one another. The aligned fluid openings 41 and seals (not shown) in a direction perpendicular to the fictitious planes 59 between the fluid openings 41 thus form a supply channel 42 for oxidant, a discharge channel 43 for oxidant, a supply channel 44 for fuel, a discharge channel 45 for fuel, a supply channel 46 for coolant, and a discharge channel 47 for coolant. The supply and discharge lines 15, 16, 25, 26, 27, 28 outside the stack of the fuel cell unit 1 are designed as process fluid lines. The supply and discharge lines 15, 16, 25, 26, 27, 28 outside the stack of the fuel cell unit 1 open into the supply and discharge channels 42, 43, 44, 45, 46, 47 inside the stack of the fuel cell unit 1.The fuel cell stack 1 together with the compressed gas storage 21 and the gas conveying device 22 forms a fuel cell system 4.

[0090] In the fuel cell unit 1, the fuel cells 2 are arranged between two clamping elements 33 as clamping plates 34. A first clamping plate 35 rests on the first fuel cell 2 and a second clamping plate 36 rests on the last fuel cell 2. The fuel cell unit 1 comprises approximately 200 to 400 fuel cells 2, which are not all shown in Figs. 4 and 5 for reasons of clarity. The clamping elements 33 apply a compressive force to the fuel cells 2, ie the first clamping plate 35 rests with a compressive force on the first fuel cell 2 and the second clamping plate 36 rests with a compressive force on the last fuel cell 2.The fuel cell stack 2 is thus clamped to ensure tightness for the fuel, the oxidant, and the coolant, particularly due to the elastic seals 11, and also to keep the electrical contact resistance within the fuel cell stack 1 as low as possible. To clamp the fuel cells 2 with the clamping elements 33, four connecting devices 37 are designed as bolts 38 on the fuel cell unit 1, which are subject to tensile stress. The four bolts 38 are connected to the chipboards 34.

[0091] Fig. 6 shows the bipolar plate 10 of the fuel cell 2. The bipolar plate 10 comprises the channels 12, 13, and 14 as three separate channel structures 29. The channels 12, 13, and 14 are not shown separately in Fig. 6, but merely simplified as a layer of a channel structure 29. The fluid openings 41 on the sealing plates 39 of the bipolar plates 10 and membrane electrode assemblies 6 (not shown) are arranged in an aligned stack within the fuel cell unit 1, so that supply and discharge channels 42, 43, 44, 45, 46, 47 are formed. Seals (not shown) are arranged between the sealing plates 39 for fluid-tight sealing of the supply and discharge channels 42, 43, 44, 45, 46, 47 formed by the fluid openings 41. The bipolar plate 10 has a length 61 and a width 62. The channel 14 orthe channels 14 for coolant as channel structure 29 have a length 63 and the width of the channel structure 29 essentially corresponds, in particular with a deviation of less than 20% or 10%, to the width 62 of the bipolar plate 10.

[0092] Since the bipolar plate 10 also fluid-tightly separates the gas chamber 31 for fuel from the gas chamber 32 for oxidizing agent and furthermore fluid-tightly seals the channel 14 for coolant, the term separator plate 51 can also be used for the bipolar plate 10 for fluid-tight separation of process fluids. Thus, the term separator plate 51 is also subsumed under the term bipolar plate 10, and vice versa. The channels 12 for fuel, the channels 13 for oxidizing agent, and the channels 14 for coolant of the fuel cell 2 are also formed on the electrochemical cell 52, but with a different function.

[0093] The fuel cell unit 1 can also be used and operated as an electrolysis cell unit 49, i.e., it forms a reversible fuel cell unit 1. Some features are described below that enable the operation of the fuel cell unit 1 as an electrolysis cell unit 49. A liquid electrolyte, namely highly diluted sulfuric acid with a concentration of approximately c (FLSO4) = 1 mol / l, is used for the electrolysis. A sufficient concentration of oxonium ions H30 + in the liquid electrolyte is necessary for electrolysis.

[0094] During electrolysis, the following redox reactions occur:

[0095] Cathode:

[0096] 4 H3O + + 4 e- -» 2 H2+ 4 H2O Anode:

[0097] 6 H2O — » O2 + 4 HsO + + 4 e'

[0098] Total reaction equation of cathode and anode: 2 H2O -» 2 H2+ O2

[0099] The polarity of the electrodes 7, 8 with electrolysis when operated as an electrolysis cell unit 49 is the opposite (not shown) to when operated as a fuel cell unit 1, so that in the channels 12 for fuel, through which the liquid electrolyte is passed, hydrogen H2 is formed as a second substance at the cathodes, and the hydrogen H2 is absorbed by the liquid electrolyte and transported along in dissolved form. Analogously, the liquid electrolyte is passed through the channels 13 for oxidizing agents and oxygen O2 is formed as the first substance at the anodes in or on channels 13 for oxidizing agents. The fuel cells 2 of the fuel cell unit 1 function as electrolysis cells 50 when operated as an electrolysis cell unit 49. The fuel cells 2 and electrolysis cells 50 thus form electrochemical cells 52. The oxygen O2 formed is absorbed by the liquid electrolyte and transported along in dissolved form.The liquid electrolyte is stored in a storage tank 54. For reasons of graphic simplification, two storage tanks 54 of the fuel cell system 4, which also functions as an electrolysis cell system 48, are shown in Fig. 1. The 3-way valve 55 on the fuel supply line 16 is switched over during operation as an electrolysis cell unit 49, so that not fuel from the compressed gas reservoir 21, but rather the liquid electrolyte is introduced into the fuel supply line 16 by a pump 56 from the storage tank 54. A 3-way valve 55 on the oxidant supply line 25 is switched over during operation as an electrolysis cell unit 49, so that not oxidant in the form of air from the gas delivery device 22, but rather the liquid electrolyte is introduced into the oxidant supply line 25 by the pump 56 from the storage tank 54.The fuel cell unit 1, which also functions as an electrolysis cell unit 49, has, in comparison to a fuel cell unit 1 that can be operated only as a fuel cell unit 1, optional modifications to the electrodes 7, 8 and the gas diffusion layer 9: for example, the gas diffusion layer 9 is not absorbent, so that the liquid electrolyte easily drains off completely, or the gas diffusion layer 9 is not formed, or the gas diffusion layer 9 is a structure on the bipolar plate 10. The electrolysis cell unit 49 with the storage container 54, the pump 56 and the separators 57, 58 and preferably the 3-way valve 55 forms an electrochemical cell system 60.

[0100] A hydrogen separator 57 is arranged on the fuel discharge line 15. The separator 57 separates the hydrogen from the electrolyte containing hydrogen, and the separated hydrogen is introduced into the compressed gas reservoir 21 by a compressor (not shown). The electrolyte discharged from the hydrogen separator 57 is then fed back to the electrolyte storage container 54 via a line. An oxygen separator 58 is arranged on the fuel discharge line 26. The separator 58 separates the oxygen from the electrolyte containing oxygen, and the separated oxygen is introduced into a compressed gas reservoir (not shown) by a compressor (not shown).The oxygen in the compressed gas storage tank for oxygen (not shown) can optionally be used to operate the fuel cell unit 1 by flowing the oxygen into the oxidant supply line 25 via a line (not shown) during operation as a fuel cell unit 1. The electrolyte drained from the oxygen separator 58 is then fed back to the electrolyte storage tank 54 via a line. The channels 12, 13 and the discharge and supply lines 15, 16, 25, 26 are designed such that after use as an electrolysis cell unit 49 and the pump 56 is switched off, the liquid electrolyte flows completely back into the storage tank 54 due to gravity.Optionally, after use as an electrolysis cell unit 49 and before use as a fuel cell unit 1, an inert gas is passed through the channels 12, 13 and the discharge and supply lines 15, 16, 25, 26 to completely remove the liquid electrolyte before the gaseous fuel and oxidant are passed through. The fuel cells 2 and the electrolysis cells 2 thus form electrochemical cells 52. The fuel cell unit 1 and the electrolysis cell unit 49 thus form an electrochemical cell unit 53. The channels 12 for fuel and the channels 13 for oxidant thus form channels 12, 13 for passing the liquid electrolyte during operation as an electrolysis cell unit 49, and this applies analogously to the supply and discharge lines 15, 16, 25, 26. For process-related reasons, an electrolysis cell unit 49 normally does not require channels 14 for passing coolant.In an electrochemical cell unit 49, the channels 12 for fuel also form channels 12 for passing fuel and / or electrolyte, and the channels 13 for oxidant also form channels 13 for passing fuel and / or electrolyte.

[0101] The bipolar plates 10 are manufactured from the first plate 64 and the second plate 65. The first plates 64 and the second plates 65, generally referred to as components 64, 65 or parts 64, 65, are manufactured using the method described in this patent application. The components 64, 65 are manufactured using the manufacturing system 71 shown in Figs. 9 and 10. The manufacturing system 71 essentially comprises first stamping tools 86 and second stamping tools 87, a press system 76 with three presses 75 as hydraulic press devices 75, and a transport system 84 as a conveyor belt 85.

[0102] Fig. 9 shows a cross-section through the first and second stamping tools 86, 87. The stamping tools 86, 87 are made of metal, for example steel or stainless steel. A recess 88 is formed on the first stamping tool 86 and a projection 89 is formed on the second stamping tool 87. On the first stamping tool 86, a sealing element 91 is formed as a first sealing element 92 as a recess 92, running completely around the recess 88. On the second stamping tool 87, a sealing element 91 is formed as a second sealing element 93 as a projection 93, running completely around the projection 89. The geometry of the first sealing element 92 as a recess 92 is complementary to the geometry of the second sealing element 93 as a projection 93.In addition, in the corner area on the first embossing tool 86, four positioning elements 94 are formed as first positioning elements 95 as recesses 95, and in the corner area on the second embossing tool 87, four second positioning elements 96 are formed as projections 96. The geometry of the first positioning elements 95 is complementary to the geometry of the second positioning elements 96. The first positioning elements 95 are formed as conically tapered recesses 95, and the second positioning elements 96 are formed as conical projections 96 or conical pins 96. When carrying out the method with the manufacturing system 71, the distance between the first embossing tool 86 and the second embossing tool 87 shown in Fig. 10 is reduced until the second positioning elements 96 are completely arranged in the first positioning elements 95.Due to the conical geometry of the positioning elements 95, 96, the two stamping tools 86, 87 with identical length and width are aligned with each other as the distance between the two stamping tools 86, 87 decreases, so that they are flush with each other. When the second positioning elements 96 are fully arranged in the first positioning elements 95 and the second sealing element 93 in the first sealing element 92, a cavity 90 forms between the projection 89 and the recess 88. The sealing elements 91 essentially function as a labyrinth seal. The geometry of the elements 91 and the positioning elements 94 is designed such that the first and second stamping tools 86, 87 are first aligned with each other and then the second sealing element 93 is moved into the first sealing element 92.The blank 82 is arranged in the cavity 90 with a sufficient distance between the first and second stamping tools 86, 87. As the distance between the first stamping tool 86 and the second stamping tool 87 decreases, a transformation process is carried out, namely the deformation of the blank 82 in the cavity 90 by pressing due to a compressive force applied to the blank 82 by the first stamping tool 86 and the second stamping tool 87, in particular the boundary of the recess 88 and the boundary of the projection 89. The projection 89 and the recess 88 have a corresponding stamping structure or stamping geometry for forming the geometry of the inner side 66 and outer sides 67 of the first and second plates 64, 65.

[0103] First, blanks 82 are provided, for example, by extrusion and / or calendering (not shown). The blanks 82 are provided as a strip with a large length and width of the components 64, 65 to be produced, as the first and second plates 64, 65, or as blanks 82 with a length and width that essentially corresponds to the length and width of the components 64, 65 to be produced, as the first and second plates 64, 65.

[0104] The production system 71 comprises a starting area 72, a central area 73, and an end area 74. The three presses 75 of the press system 76 are arranged in the central area 73. The press 75 is a hydraulic pressing device 75 with an upper and lower pressure plate. The lower pressure plate is stationary and / or immovable, and the upper pressure plate is movable in the vertical direction by a hydraulic piston (not shown) for applying a compressive force to the first and second stamping tools 86, 87.In the initial region 72 of the production system 71, the distance between the first and second stamping tools 86, 87 is reduced during the continuous or discontinuous movement using a transport system 84 (not shown), for example a conveyor belt 85 and / or at least one industrial robot (not shown), and the transport system 84 is configured as a conveyor belt 85, so that the stamping tools 86, 87 are aligned with one another using the positioning elements 94, and subsequently a projection 89 of each of the second stamping tools 87 is placed in a respective recess 88 of the first stamping tools 86 in the initial region 72. In addition, a blank 82 is inserted into each of the recesses 88 of the first stamping tools 86, for example using a robot (not shown) as an industrial robot.When forming the blank 82 with a significantly greater length and / or width than the recess 88, the excess material of the blank 82 is folded toward one another during the movement of the first and second stamping tools 86, 87. When forming the blanks 82 with a length and width substantially equal to the length and width of the recesses 88, only a small amount of excess material is folded and / or pressed out during the movement of the first and second stamping tools 86, 87. Each stamping tool 86, 87 can have one recess 88 and one projection 89 or several recesses 88 and several projections 89.

[0105] In the central area 73 of the production system 71, a total of three presses 75 are arranged, forming the press system 76. Each press 75 forms a thermal processing station 77. The first press 75 forms a first thermal processing station 78, the second press 75 forms a second thermal processing station 79, and the third press 75 forms a third thermal processing station 80. The first and second presses 75 additionally form a mechanical processing station 97.

[0106] The first and second embossing tools 86, 87 are introduced into the first press 75 by the transport system 84 after the first and second embossing tools 86, 87 have been placed on top of one another and positioned relative to one another in the initial region 72. After inserting a first and a second stamping tool 86, 87, an upper hydraulically operated pressure plate of the press 75 is placed on the second stamping tool 87 and the first and second stamping tools 86, 87, which are already aligned with one another, are pressed together with a compressive force so that the sealing elements 91 seal, ie the second sealing elements 93 are arranged completely in the first sealing elements 92 and the remaining mutually facing sides of the first and second stamping tools 86, 87 lie on one another and a reduction of the cavities 90 is carried out with an essentially isobaric change in the state of the blanks 82 in the cavities 90 as deformation of the blanks 82 with a compressive force.Thus, consolidation is performed as a reduction in the volume of the blanks 82 in the first and second stamping tools 86, 87. This compressive force, as pressing, causes a transformation process as deformation of the blanks 82 into the first and second plates 64, 65 due to the geometry of the first and second stamping tools 86, 87 at the cavity 90, so that the first and second plates 64, 65 are formed with a wave structure as a wavy geometry and fluid openings 41. After the transformation process as deformation of the blanks in the first press 75 has been performed, the upper pressure plate of the first press 75 is raised, and then the first and second stamping tools 86, 87 are transported and conveyed from the first press 75 to the second press 75 by the transport system 84.In the second press 75, the modification process, namely the deformation of the blanks 82, is carried out in a similar manner to the first press 75, and further consolidation is carried out by reducing the volume of the blanks 82. The first and second presses 75 thus each form a mechanical processing station 97 for the modification process, namely the deformation of the blanks 82. Thermal processing stations 77, comprising a first thermal processing station 78 and a second thermal processing station 79, are formed in the central region 73 of the production system 71. The first thermal processing station 78 is formed by the first press 75, and the second thermal processing station 79 is formed by the second press 75. In the first and second thermal processing stations 78, 79, the embossing tools 86, 87, and thus also the blanks 82, or the already deformed blanks 82, as the first and second plates 64, 65, are heated.For this purpose, heating devices are integrated into the pressure plates of the presses 75, for example channels for passing a heating fluid and / or at least one electrical resistance heating element.

[0107] A third thermal processing station 80 is formed by the third press 75. In the third thermal processing station 80, the third press 75, the blanks 82 are cooled, for example, to a temperature below 50°C. For this purpose, channels for the passage of a cooling fluid are formed, for example, in the pressure plates of the third press 75.

[0108] A gap (not shown) is optionally provided between the first and second thermal processing stations 78, 79 on the one hand and the third thermal processing station 80 on the other, so that between the second and third thermal processing stations 79, 80, the embossing tools 86, 87 with the components 64, 65 are initially slowly cooled, and in the third thermal processing station 80, rapid active cooling with a cooling fluid is carried out. Due to the heating and cooling of the thermal plastic, the transformation process of hardening the blanks 82 into the finished first and second plates 64, 65 as components 64, 65 is carried out.After passing through the two mechanical processing stations 97, the volume of the cavity 90 remains constant in the subsequent processing station as the third thermal processing station 80 with a first and second embossing tools 86,87, so that in the third thermal.

[0109] Processing station 80, an isochoric change process with constant volume is carried out in the cavities 90. In the end region 74 of the production system 71, the contact between the first and second stamping tools 86, 87 is eliminated and the distance between the first and second stamping tools 86, 87 is increased, preferably continuously or discontinuously, so that the finished components 64, 65 can be removed from the recesses 88 of the first stamping tools 86. The distance between the first and second stamping tools 86, 87 at the end region 74 of the production system 71 is implemented, for example, with a transport system 84, in particular an industrial robot (not shown) and / or a correspondingly designed conveyor belt 85.

[0110] The removal, i.e. the removal of the formed and hardened components 64, 65 from the stamping tools 86, 87, takes place, for example, due to bending of bendable stamping tools 86, 87, due to gravity and / or by means of an industrial robot. After the removal of the finished components 64, 65 or parts 64, 65 from the stamping tools 86, 87, a continuous or discontinuous return transport of the first and second stamping tools 86, 87 takes place from the end region 74 to the start region 72 of the production system 71 with the transport system 84, for example the conveyor belt 85 and / or an industrial robot, not shown. During the return transport of the stamping tools 86, 87, the cleaning of the stamping tools 86, 87 is carried out in at least one cleaning station 83. In at least one conditioning station 81, after cleaning, an anti-adhesion agent is applied to the mutually facing sides of the embossing tools 86, 87.

[0111] The bipolar plates 10 are manufactured from the first plate 64 and the second plate 65. For this purpose, for each bipolar plate 10, a correspondingly corrugated first and second plate 64, 65 are placed on top of one another and stacked so that the inner sides 66 of the first and second plates 64, 65 lie on one another at strip-shaped contact areas 68 as a joint. This is carried out in a post-processing station (not shown). The post-processing station (not shown) is formed, for example, by an industrial robot and / or a press 75. In the post-processing station, a first plate 64 rests on the second plate 65 with a substantially constant compressive force. The fictitious planes 59, spanned by the disk-shaped first and second plates 64, 65, are aligned substantially parallel to one another.The first and second plates 64, 65, made of a composite material comprising a mixture of a plastic, in particular a thermoplastic, and at least one electrically conductive filler, each have an outer side 67 opposite the inner sides 66. After the two plates 64, 65 are arranged one above the other for the production of the bipolar plates 10 in the post-processing station, strip-shaped channels 14 for coolant are formed outside the strip-shaped contact regions 68 between the inner sides 66 of the first and second plates 64, 65, forming an intermediate space. The geometry of the provided first and second plates 64, 65 with a large number of corrugations requires that a large number of channels 14 be formed between the contact regions 68.In addition, channels 12 for fuel and channels 13 for oxidant are formed on the outer sides 67 of the plates 64, 65 as a large number of corrugations with a small radius. The geometry of the inner sides 66 and outer sides 67 of the first and second plates 64, 65 is determined by the geometry of the recesses 88 of the first stamping tools 86 and the projections 89 of the second stamping tools 87.

[0112] The first and second plates 64, 65 are bonded to one another with adhesive to form the bipolar plate 10 in the post-processing station (not shown), so that an adhesive connection 69 is produced as a large number of adhesive seams 70 as connecting seams 70 between the first and second plates 64, 65. For this purpose, before the first and second plates 64, 65 lie on top of one another, adhesive is applied in strips to the corresponding areas on the inner side 66 of the first plate 64 and / or on the inner sides 66 of the second plate 65 using an industrial robot. The adhesive seam 70 made of adhesive is designed to be completely continuous and fluid-tight at edge regions near the long and wide sides of the bipolar plate 10 to seal the space between the coolant and prevent the coolant from flowing out.Optionally, further, sectionally formed adhesive seams 70 can be produced at the contact areas 68. These adhesive seams do not have a sealing function for the coolant to the environment or to the outside and merely serve to firmly connect the two plates 64, 65 and optionally also function as a seal between two channels 14 for coolant. In the area of ​​the fluid openings 41, adhesive seams 70 are produced circumferentially around the fluid openings 41 in order to prevent an uncontrolled flow of the process fluids into the space between the first and second plates 64, 65. In addition, an adhesive seam 70 is produced completely circumferentially in the area of ​​the long and wide sides of the bipolar plate 10 in order to seal the space from the environment. Instead of the adhesive seam 70, another connecting seam 70 can also be produced, for example, as a weld seam 70.

[0113] Overall, the inventive method for producing the components 64, 65 or the parts 64, 65 and the inventive method for producing the electrochemical cell unit 53 offer significant advantages. The components 64, 65 are manufactured discontinuously in the press system 76. The presses 75 are standardized hydraulic industrial presses 75 as hydraulic pressing devices, so they are inexpensive to purchase. A large number of bipolar plates 10 can thus be advantageously manufactured industrially at low cost.

Claims

Claims 1. A method for producing components (5, 6, 7, 8, 9, 10, 30, 51, 64, 65) for an electrochemical cell unit (53) for converting electrochemical energy into electrical energy as a fuel cell unit (1) and / or for converting electrical energy into electrochemical energy as an electrolysis cell unit (49), comprising the steps of: providing blanks (82), inserting the blanks (82) into first stamping tools (86) and / or second stamping tools (87), carrying out a transformation process as deformation of the blanks (82) into the components (5, 6, 7, 8, 9, 10, 30, 51, 64, 65) while the blanks (82) are arranged between the first and second stamping tools (86, 87), Removing the formed components (5, 6, 7, 8, 9, 10, 30, 51, 64, 65) from the first stamping tools (86) and from the second stamping tools (87), characterized in that the change process is carried out as deforming the blanks (82) into the components (5, 6, 7, 8, 9, 10, 30, 51, 64, 65) while the blanks (82) are arranged between the first and second stamping tools (86, 87) with at least one press (75).

2. Method according to claim 1, characterized in that the change process is carried out as deformation of the blanks (82) to the components (5, 6, 7, 8, 9, 10, 30, 51, 64, 65) while the blanks (82) are arranged between the first and second stamping tools (86, 87). are carried out one after the other using a plurality of presses (75) of a press system (76) arranged in series, so that at least one blank (82) carries out the change process one after the other between an identical first and second stamping tool (86, 87) in the plurality of presses (75).

3. Method according to claim 2, characterized in that in at least one of the presses (75) arranged in series, consolidation is carried out as a reduction of the volume of the blanks (82).

4. Method according to one or more of the preceding claims, characterized in that the process of transforming the blanks (82) into the components (5, 6, 7, 8, 9, 10, 30, 51, 64, 65) is carried out by thermally treating the blanks (82).

5. Method according to claim 4, characterized in that the blanks (82) are thermally treated, while a blank (82) is arranged in a cavity (90) between the first and second stamping tools (86, 87) and a compressive force is applied to the first and second stamping tools (86, 87) by a press (75).

6. Method according to claim 4 or 5, characterized in that the blanks (82) are thermally treated by heating the blanks (82).

7. Method according to one or more of claims 4 to 6, characterized in that the blanks (82) are thermally treated by cooling the blanks (82).

8. Method according to claim 6 or 7, characterized in that the blanks (82) are first heated and then cooled.

9. Method according to one or more of claims 2 to 8, characterized in that the execution of a change process as deformation of the blanks (82) to the components (5, 6, 7, 8, 9, 10, 30, 51, 64, 65) while the blanks (82) are arranged between the first and second stamping tools (86, 87) is carried out substantially isobarically.

10. Method according to one or more of the preceding claims, characterized in that the substantially isobaric modification process of the blanks (82) is carried out in a press (75) each.

11. Method according to one or more of the preceding claims, characterized in that During the execution of the change process as deformation of the blanks (829) to the components (5, 6, 7, 8, 9, 10, 30, 51, 64, 65) while the blanks (82) are arranged between the first and second stamping tools (86, 87), excess composite material is diverted from a respective cavity (90) between the first and second stamping tools (86, 87) through a channel, in particular a dipping edge.

12. Method according to one or more of the preceding claims, characterized in that the blanks (82) are made of a composite material made of a mixture of a plastic, in particular thermoplastic and / or thermosetting plastic, and at least one electrically conductive filler.

13. Method according to one or more of the preceding claims, characterized in that the method is carried out with presses (75) as hydraulic pressing devices (75) with at least one hydraulic piston and at least one hydraulic cylinder in that the at least one hydraulic piston is subjected to a hydrostatic pressure force of the hydraulic fluid.

14. Method according to one or more of the preceding claims, characterized in that Bipolar plates (10) are produced with the following steps: providing first plates (64) and second plates (65) by carrying out a method according to one or more of the preceding claims, Stacking the first plates (64) and the second plates (65) on top of each other so that a first and a second plate (64, 65) lie on top of each other, Producing at least one connection, in particular at least one material connection, between the first and the second plate (64, 65).

15. A method for producing an electrochemical cell unit (53) for converting electrochemical energy into electrical energy as a fuel cell unit (1) and / or for converting electrical energy into electrochemical energy as an electrolysis cell unit (49) with stacked electrochemical cells (52) with the steps: providing layered components (5, 6, 7, 8, 9, 10, 30, 51, 64, 65) of the electrochemical cells (52), namely preferably ion exchange membranes, in particular proton exchange membranes (5), anodes (7), cathodes (8), preferably gas diffusion layers (9) and bipolar plates (10, 51, 64, 65), Stacking the layered components (5, 6, 7, 8, 9, 10, 30, 51, 64, 65) to form electrochemical cells (52) and a stack of the electrochemical cell unit (53), characterized in that the components (5, 6, 7, 8, 9, 10, 30, 51, 64, 65), in particular bipolar plates (10, 51, 64, 65), are provided by carrying out a method according to one or more of the preceding claims.

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