Sealing device as cell periphery for an electrolysis cell stack

Description

[0001] The invention relates to an electrolysis device for producing gaseous hydrogen, as defined in the claims. The disclosed electrolysis device is particularly characterized by a sealing device that ensures a particularly high and long-term, reliable degree of tightness of the electrolysis device.

[0002] EP1601041B1 shows a fuel cell stack with a spring module. This spring module comprises two mutually displaceable components and a plurality of springs arranged between the first and second components. Furthermore, the fuel cell stack has an adjusting screw and an end plate, with the spring module being arranged between the end plate and a stack of fuel cells, and the adjusting screw being arranged between the spring module and the end plate. With regard to safety and usability, especially with regard to sealing the cell stack, this known design represents only a partially satisfactory technical solution.

[0003] Furthermore, DE10058381B4 presents an adaptive pressure distribution system for a modular, multifunctional fuel cell stack, which comprises stainless steel bolts, a fiber-reinforced plastic carrier, adapted seals, and other elements. Furthermore, this device features spiral disc springs with integrated washers at at least one end to brace the fuel cell stack for uniform pressure buildup and pressure maintenance. Again, this disclosed technical solution for building up a preload pressure for sealing is only partially satisfactory.

[0004] The object of the present invention was to overcome the disadvantages of the prior art and to provide a device and a method by means of which, among other things, the operational reliability and effectiveness of an electrolysis device is increased.

[0005] This object is achieved by a device and a method according to the claims.

[0006] The electrolysis device according to the invention for generating gaseous hydrogen comprises at least one electrolysis cell running along a cell axis, which is constructed from plate-shaped elements stacked or arranged in series along the cell axis. Furthermore, the electrolysis device comprises at least two openings in the plate-shaped elements, which openings each form flow channels whose main directions run along the cell axis. In this sense, the term "main direction" is to be understood as meaning that the main orientation of a straight line averaged in a longitudinal projection of a flow channel shows a main direction of a flow channel, which main direction runs along the cell axis, although this does not necessarily have to be parallel to the cell axis. In particular, the main direction of a flow channel runs along the main direction of the cell axis.

[0007] Furthermore, the electrolysis device comprises at least one sealing means or a sealing device to ensure the tightness of the electrolysis device. This sealing means comprises a first abutment element and a second abutment element, which abutment elements are spaced apart from one another in the direction of the cell axis. Furthermore, the sealing means comprises a first pressure plate and a second pressure plate, which are spaced apart from one another in the direction of the cell axis and are arranged between the first abutment element and the second abutment element, wherein the at least one electrolysis cell is arranged between the first pressure plate and the second pressure plate. The sealing means further comprises at least one holding element to hold the first abutment element and the second abutment element at a predetermined distance along the cell axis. Furthermore, at least one elastically deformable orspring-elastic pressure element formed at least between a pair of abutment element and a pressure plate lying closest to one another.

[0008] In this electrolysis device, it is provided that at least one elastically deformable pressing element is assigned to each of the flow channels, and that a pressing element cross-section projected along the cell axis of at least one of these pressing elements is positioned so as to at least partially overlap a flow channel cross-section projected along the cell axis.

[0009] The advantage here is that the at least one elastically deformable pressure element creates a directed force cone, so that the force flow is directed in the direction of the main alignment of a flow channel. This results in improved sealing, particularly in the area of the flow channel, with respect to the surrounding or outer region of the electrolysis device and with respect to an inner region of the electrolysis cell. The improved sealing of the flow channels with respect to the inner region is particularly noteworthy here, as this results in increased safety and a particularly low hazard potential of the electrolysis device. At the same time, improved sealing of the electrolysis device with respect to the outer region results in increased effectiveness of the electrolysis device, since hydrogen, as the smallest element in the periodic table, has a high tendency to diffuse in relation to its dimensions in the molecular state.

[0010] A further positive effect that is particularly worth highlighting is that the interaction of the abutment element, the pressure plate, and the at least one elastically deformable pressure element ensures improved sealing of the electrolysis device, particularly during pressure operation. This is particularly noticeable in the case of pulsating pressure operation in combination with process-related temperature changes, which combined operating conditions are certainly reflected in the operation of an electrolysis device. Through the described interaction, in particular through the use of the disclosed sealing device or the sealing means used for this purpose, sliding of sealing planes, which may be associated with the plate-shaped elements, can be controlled in a defined manner. This subsequently results in increased operational reliability with a simultaneously expanded operating spectrum and a prolonged service life.a longer-term, uninterrupted service life of the electrolysis device can be achieved.

[0011] Another advantageous embodiment provides that each of the flow channels is assigned a pressure element, and that a central axis of each of the pressure elements is aligned with the main direction of the respective flow channels. This embodiment is particularly advantageous when process- and / or operationally induced, swelling temperature and / or pressure fluctuations within the electrolysis cell result in thermal expansion of the plate-shaped elements, thereby causing the plate-shaped elements to slide relative to one another. Due to the pressure or force introduction aligned with the flow channels and the associated formation of a force cone along the main directions of the flow channels, a relative sliding offset of individual plate-shaped elements relative to the respective flow channel is prevented.This prevents changes in the flow cross-section of the flow channels and at the same time improves the sealing of the flow channels and increases the safety of the electrolysis device.

[0012] Furthermore, it can be provided that the flow channels are formed by elliptical openings in the plate-shaped elements and that two pressure elements are assigned to each flow channel. This creates the mutually positive effect that, on the one hand, with appropriate alignment, the elliptical flow channels have a reduced inner surface of the flow channel in the vicinity of the outer and inner surfaces of the electrolysis cell, while at the same time, a uniform flow throughput is ensured by the appropriate dimensioning of the elliptical flow channel cross-section. On the other hand, there is the synergistic effect that the two pressure elements assigned to each flow channel again bring about improved sealing of the elliptical flow channels along the main axis of the elliptical flow channel cross-section.

[0013] Furthermore, it may be expedient for the flow channels to be distributed in the circumferential direction of the electrolysis device, wherein the normal distance of the central axis from the cell axis of a pressure element assigned to the respective flow channel is smaller than the normal distance of the main direction from the cell axis of the respective flow channel. Particularly advantageous in this case is the force cone created by the pressure elements, offset towards the interior of the electrolysis cell, for improved sealing of the flow channels with respect to this interior of the electrolysis cell. As already mentioned, the tightness of the flow channels with respect to the interior of the electrolysis cell is particularly important due to the reactivity of the electrolysis product gases. This measure thus ensures improved operational reliability.

[0014] Furthermore, it can be provided that the at least one holding element comprises a guide arrangement by which the first pressure plate and / or the second pressure plate is adjustably guided relative to the first abutment element and / or the second abutment element along the cell axis. This advantageous embodiment ensures that the tightness of the electrolysis device is optimally ensured at all times by guiding the pressure plates in dynamically occurring operating modes or operating states. Particularly with regard to strongly fluctuating temperatures and the resulting thermal expansion of the components of the electrolysis device, the described embodiment prevents excessive sliding of the plate-shaped elements.At the same time, all components of the electrolysis device are protected because dynamic effects are cushioned, for example, excessive surface pressure due to thermal expansion of individual sensitive elements is avoided. As a result, thinner plate-shaped elements can be used, which has far-reaching positive effects on production technology and thus also on the economy. This advantageous design is particularly beneficial with regard to the economical interchangeability of individual components and the associated resource-saving operation over multiple life cycles of an electrolysis device.

[0015] According to a particular embodiment, it is possible for the at least one holding element to comprise a bolt, a pin, a cable or in particular a screw, or to be formed by at least one of these elements, which at least one holding element extends through the first and the second pressure plate in the direction of the cell axis. This results, on the one hand, in a very compact design of the entire electrolysis device, which has far-reaching advantages with regard to its use in a system with a modular structure, for example. Secondly, this embodiment promotes ideal guidance of the pressure plates along the guide arrangement, in particular guidance that is as free from jamming and smooth as possible, which in turn results in a more even surface pressure between the plate-shaped elements compared to conventional embodiments.

[0016] Another advantageous embodiment is one in which the elastically deformable pressure elements are formed by helical springs and / or disc springs, in particular by equally layered disc springs, wherein a first group of these pressure elements is each penetrated by a holding element in the direction of the cell axis. This results in a more uniform pressure across the entire cross-section of the electrolysis device and thus also in improved sealing for the electrolysis cell. Furthermore, the temperature- and pressure-related sliding of the plate-shaped elements is improved by avoiding local stress peaks. At the same time, this uniformity enables the use of thinner pressure plates and creates the possibility of using pressure plates made of plastics or other less rigid materials than metals.Thus, the guarantee of the rigidity and stability of the electrolysis device is transferred to the abutment elements and at the same time an improved sealing during dynamic operation is achieved through the increased flexibility of the pressure plates.

[0017] Furthermore, it can be provided that a second group of pressure elements is formed by the pressure elements assigned to the flow channels, which pressure elements of the second group have a different, in particular a higher, pressure force than the pressure elements of the first group. Thus, an advantageous embodiment is created in which the pressure of the plate-shaped elements across the entire contact surface can be ideally controlled according to the requirements regarding the sliding of the plate-shaped components during thermal expansion and / or compressive stresses.For example, a high contact force in the area of the flow channels and a comparatively lower contact force, taking into account the resulting and overlapping force cones, can be set in order to impose a defined direction of expansion, a defined expansion shape and magnitude on the sliding of the plate-shaped elements with regard to the operational requirements.

[0018] In particular, it can be advantageous to arrange at least one elastically deformable pressure element between each of the closest pairs, each consisting of an abutment element and a pressure plate. It is advantageous that the pressure of the plate-shaped elements is adjustable from both sides or both axial ends of the electrolysis device, or is optimally designed to ensure tightness along the cell axis across all plate-shaped elements. The effect of the pressure element is thus evened out over the length of the cell stack by the arrangement on both sides, which primarily results in the further synergistic effect that electrolysis devices with a plurality of electrolysis cells can be ideally sealed, as already explained.Thus, an economic advantage can be achieved compared to the known embodiments, whereby the advantages already described above with regard to the conservation of resources for the production of individual components of the electrolysis device are further enhanced.

[0019] Furthermore, it may be expedient if the sealing means or the sealing device is designed asymmetrically with respect to a center plane of the electrolysis device aligned perpendicular to the cell axis with respect to the number and / or design of the elastically deformable pressure elements. Since, in an electrolysis device with multiple half-cells within the electrolysis cell, the pressure levels and temperature stresses are not necessarily evenly distributed along the cell axis or symmetrical with respect to a normal plane of the cell axis, it is advantageous to respond to this inhomogeneity by means of the elastically deformable pressure elements. Thus, the individual adaptation of the pressure elements has the advantageous effect of further improving the sealing of the entire electrolysis device over the entire extension length, i.e., along the cell axis.

[0020] According to an advantageous development, it can be provided that the at least one elastic pressure element is slidably positioned in the direction of the cell axis by means of pockets and / or a mandrel provided in the respective abutment element and / or in the respective pressure plate. The precise positioning of the at least one pressure element is advantageous in this case. Furthermore, this development results in the simple possibility of using pressure elements that are composed of individual elements that are not permanently connected, thereby enabling a precise influence on the compression spring characteristic curve of the pressure elements as well as on the line pressure of the same at their contact surfaces with the abutment element and pressure plate.In particular, the maximum spring deflection can subsequently be influenced by this further development, which is particularly advantageous with regard to an indication of the operating limits of the electrolysis device in order to detect any damage or excessive stress at an early stage.

[0021] Furthermore, the stiffness of a pressure plate can be less than or equal to the stiffness of the abutment element closest to it. This is advantageous because component unevenness is absorbed or at least partially compensated by the pressure plate, while at the same time, the abutment element, in conjunction with the entire sealing device, ensures the stability of the electrolysis device. At the same time, fatigue phenomena of the pressure elements can be compensated for.

[0022] Furthermore, the pressure plate can be provided with flat receiving surfaces for the elastic pressure elements, which are connected by web-like structural elements. Advantageously, the flat receiving surfaces, in conjunction with the web-like structural elements, improve the formation of a specified force cone for precise sealing of the flow channels, depending on their requirements due to the load exerted by the pressure elements. At the same time, the directed force flow achieved through a suitable arrangement of the web-like structural elements results in a reduction in material used for the pressure plates, which not only conserves resources but also subsequently brings economic advantages.

[0023] Furthermore, a method for sealing an electrolysis device is provided, wherein a first pair consisting of a pressure plate and a nearest abutment element with pressure elements assigned to the first pair is prestressed by means of a prestressing device and arranged along the cell axis. Subsequently, at least one electrolysis cell constructed from plate-shaped elements is stacked adjacent to the first pair along the cell axis. In addition, a second pair consisting of a pressure plate and a nearest abutment element with pressure elements assigned to the second pair is prestressed by means of a further prestressing device and arranged adjacent to the at least one electrolysis cell along the cell axis. Furthermore, the abutment element of the first pair is held at a predetermined distance from the abutment element of the second pair by means of at least one holding element.Finally, each pre-tensioning device is released from the respective pair of pressure plate and abutment element and the pre-tensioning force of the sealing device is finely adjusted by means of the at least one holding element so that the sealing of the plate-shaped elements of the at least one electrolysis cell and thus of the electrolysis device is achieved.

[0024] The main advantage of this process is that the respective pair of pressure plate and the nearest abutment element, along with the associated pressure elements, is stacked or lined up in a pre-stressed state along the cell axis. This allows for a predefined pre-stress during the assembly process, thus sealing the electrolysis device using the sealing device. Furthermore, the compressive force on the flat sides of the plate-shaped elements can be evened out, preventing inhomogeneous loading during the assembly process. This achieves radially uniform tension, which is particularly advantageous with regard to the service life of the plate-shaped elements used.

[0025] For a better understanding of the invention, it is explained in more detail using the following figures.

[0026] They show in a highly simplified, schematic and exemplary representation: Fig. 1 an exploded view of a possible embodiment of the electrolysis device; Fig. 2 the electrolysis device according to Fig. 1in perspective view; Fig. 3 a sectional view through the electrolysis cell of the electrolysis device to illustrate a possible embodiment of the flow channels through the plate-shaped elements of the electrolysis cell in connection with the arrangement of spring-elastic pressure elements; Fig. 4 a representation of a longitudinal section through the electrolysis device in a highly simplified and schematic representation; Fig. 5 a representation of the projected cross sections of the pressure elements, flow channels and holding elements in an inventive embodiment of the arrangement of the pressure elements; Fig. 6 a possible embodiment of the pressure plate and the flow channels through the plate-shaped elements; Fig. 7 a possible embodiment of the pressure plate in a highly simplified and schematic representation;

[0027] By way of introduction, it should be noted that in the variously described embodiments, identical parts are provided with identical reference symbols or component designations. The disclosures contained throughout the description can be applied analogously to identical parts with identical reference symbols or component designations. Furthermore, the positional information chosen in the description, such as top, bottom, side, etc., refers to the directly described and illustrated figure, and these positional information must be applied analogously to the new position in the event of a change in position.

[0028] In accordance with the list of reference symbols, terms from the list of reference symbols are used with and / or without a specific index in the description. If a precise differentiation of the terms with regard to their specific embodiment is not necessary, no indexes are used. Conversely, for example, a pressing element 12a can be differentiated from a pressing element 12b according to the respective description, whereby both continue to be a pressing element 12.

[0029] In the Fig. 1An exploded view of an embodiment of the electrolysis device 1 is shown. The electrolysis device 1 comprises at least one electrolysis cell 3 arranged along the cell axis 2, which electrolysis cell 3 can be constructed from plate-shaped elements 4 stacked along the cell axis 2. The plate-shaped elements 4 can comprise flow channels 5, which are formed by openings in the plate-shaped elements 4. In particular, the flow channels 5 running parallel or substantially parallel to the cell axis 2 are formed by the openings in the plate-shaped elements 4, which are arranged serially or adjacent to one another. Furthermore, the electrolysis device 1 comprises sealing means, in particular at least one sealing device 7, which is arranged in the Fig. 1for the sake of clarity, the sealing device 7 can comprise two abutment elements 8, two pressure plates 9, and elastically deformable pressing elements 12. Furthermore, the flow channels 5 can have a fluidic connection to the pressure plates 9, if, for example, any deflection channels, connecting channels, and / or fluid connections for the electrolysis device 1 are provided in the pressure plates 9. As shown, the electrolysis device 1 can comprise holding elements 10, which holding elements 10 in this possible embodiment are realized by means of screws 10a and nuts 10b. It can be seen that the plate-shaped individual components of the electrolysis device 1 are stacked orare arranged in a row and that the sealing device 7 can be formed from two pairs, each consisting of a pressure plate 9 and the nearest abutment element 8 with pressure elements 12 arranged between them. The electrolysis cell 3 is arranged between these two pairs, each consisting of a pressure plate 9 and a nearest abutment element 8, which are arranged at the end faces. It is possible for a plurality of electrolysis cells 3x to be arranged between these pairs. In other words, the pairs, each consisting of a pressure plate 9 and a nearest abutment element 8, are formed at the axial end faces of the electrolysis device 1 with respect to the cell axis 2.

[0030] Furthermore, it can be provided that at least one elastically deformable pressure element 12a, 12b, 12c, 12d is assigned to each of the flow channels 5a, 5b, 5c, and 5d. As shown in the illustrated embodiment, the pressure elements 12 can be designed, for example, as equally layered disc springs. A first group 17 of these pressure elements 12 can each have a holding element 10 passing through it in the direction of the cell axis 2. Furthermore, a second group 18 of the pressure elements 12 can be formed by the pressure elements 12 assigned to the flow channels 5a, 5b, 5c, and 5d. Additional pressure elements 12 can also be assigned to this second group 18, as shown by way of example in this embodiment.The pressing elements 12 of the second group 18, especially the pressing elements 12 which are each assigned to a flow channel 5, can have a different, in particular a higher pressing force than the pressing elements of the first group 17.

[0031] Fig. 2 shows the design of the electrolysis device according to Fig. 1in assembled state. For supplying the electrolysis device 1 and / or for removing products from the electrolysis device 1, corresponding fluid connections 24 can be provided in the pressure plates 9a and 9b, wherein, in this sense, gaseous components or multiphase mixtures can also be supplied and / or removed via the fluid connections 24. Thus, as already mentioned, flow channels 5 of the electrolysis device 1 can have a fluidic connection in the pressure plates 9 to the fluid connections 24. An embodiment is also conceivable in which all fluid connections 24 of the electrolysis device 1 are arranged on a common pressure plate 9 or on a flat side 25 of a pressure plate 9.

[0032] In the Fig. 3the flow channels 5 in the plate-shaped elements 4 of the electrolytic cell 3 are shown in connection with the arrangement of the pressure elements 12, wherein again the same reference numerals or component designations are used for the same parts as in the previous Fig. 1 and Fig. 2 To avoid unnecessary repetition, please refer to the detailed description in the previous Fig. 1 and Fig. 2 It shows the Fig. 3a plurality of electrolysis cells 3x, which are constructed from plate-shaped elements 4 along the cell axis 2. In this optionally independent embodiment, it is evident that a respective pressure element 12a, 12b can be assigned to a respective flow channel 5a and / or 5b, wherein the respective central axis 15a, 15b of each of the pressure elements 12a, 12b can be aligned with the main direction 6a, 6b of the respective flow channel 5a and / or 5b. Preferably, a group of pressure elements 12a, 12b is provided at each of the two axial ends of the electrolysis device 1, as best shown in Fig. 4 is evident.

[0033] In the Fig. 4 is a representation of a longitudinal section through the electrolysis device 1, wherein again the same reference numerals or component designations are used for the same parts as in the previous Fig. 1 , Fig. 2 and Fig. 3To avoid unnecessary repetition, please refer to the detailed description in the previous Fig. 1 , Fig. 2 and Fig. 3 It shows the Fig. 4that a holding element 10 can comprise a guide arrangement 16, by means of which the first pressure plate 9a and / or the second pressure plate 9b is adjustably guided relative to the first abutment element 8a and / or second abutment element 8b along the cell axis 2. This results in the advantageous effects already described with regard to the sealing effect of the sealing device or the sealing means 7. Furthermore, a holding element 10 can be formed by a combination of a screw 10c with a nut 10d, which at least one holding element 10 passes through the first and the second pressure plate 9a, 9b in the direction of the cell axis 2. Furthermore, it can be provided that pressure elements 12 are positioned so as to be slidable in the direction of the cell axis 2 by means of a mandrel 21 provided in the respective abutment element 8 and / or in the respective pressure plate 9.

[0034] In the Fig. 5an arrangement or relative positioning of the projected cross sections of the pressure elements 12, the flow channels 5 and holding elements 10 is shown, wherein again the same reference numerals or component designations are used for the same parts as in the previous Fig. 1 to Fig. 4 To avoid unnecessary repetition, please refer to the detailed description in the previous Fig. 1 to Fig. 4 It shows the Fig. 5According to claim 1, an electrolysis device 1, wherein a pressure element cross-section 13 projected along the cell axis 2 of at least one of the pressure elements 12 is positioned so as to at least partially overlap a flow channel cross-section 14 projected along the cell axis 2. Furthermore, it is shown that the flow channels 5 can be provided distributed in the circumferential direction U of the electrolysis device 1, wherein the normal distance N2 of the central axis 15 to the cell axis 2 of a pressure element 12 assigned to the respective flow channel 5 can be less than the normal distance N1 of the main direction 6 to the cell axis 2 of the respective flow channel 5. This embodiment brings about the advantageous effects already described, wherein an embodiment is also conceivable in which the normal distance N1 can be less than or equal to the normal distance N2.This possible embodiment is conceivable if the design advantages outweigh those of another possible embodiment. To still achieve the described advantageous effects, it is also advantageous to use pressure elements 12 with a force application directed by the design.

[0035] In the Fig. 6 an embodiment of a pressure plate 9 and the flow channels 5 through the plate-shaped elements 4 is shown, wherein again the same reference numerals or component designations are used for the same parts as in the previous Fig. 1 to Fig. 5 To avoid unnecessary repetition, please refer to the detailed description in the previous Fig. 1 to Fig. 5 It shows the Fig. 6that it can be provided that pressure elements 12 can be held or positioned so as to be slidable in the direction of the cell axis 2 by means of pockets 20 provided in the respective abutment element 8 and / or in the respective pressure plate 9z. Furthermore, the possible design of the flow channels 5o and 5p in the form of a respective elliptical opening 26 is shown. This possible design of the electrolysis device 1 brings with it the advantageous effects described above.

[0036] In the Fig. 7 an embodiment of a pressure plate 9y is shown in a highly simplified and schematic representation, wherein again the same reference numerals or component designations are used for the same parts as in the previous Fig. 1 to Fig. 6 To avoid unnecessary repetition, please refer to the detailed description in the previous Fig. 1 to Fig. 6This embodiment shows that the pressure plate 9y can have flat receiving surfaces 22 for the elastic pressure elements 12, which receiving surfaces 22 can be connected by means of web-like structural elements 23. The web-like structural elements 22 can be arranged rotationally symmetrically with respect to the cell axis 2, so that a rotationally symmetrical pattern of the recesses can result from the pressure plate 9y. This embodiment brings about the advantageous effects described above, wherein it is also possible to achieve that, with regard to the material selection of the pressure plate 9y, plastics or less rigid materials than metals can now be provided.

[0037] The scope of protection is determined by the claims. However, the description and drawings must be used to interpret the claims. Individual features or combinations of features from the various embodiments shown and described may represent independent inventive solutions in their own right.

[0038] For the sake of clarity, it should finally be pointed out that, in order to better understand the structure, some elements have been shown out of scale and / or enlarged and / or reduced in size. Reference symbol list

[0039] 1 Electrolysis device 2 Cell axis 3 Electrolysis cell 4 Plate-shaped elements 5 Flow channel 6 Main direction 7 Sealing agent 8 Abutment element 9 Pressure plate 10 Holding element 11 Distance 12 Pressure element 13 Pressure element cross-section 14 Flow channel cross-section 15 Central axis 16 Guide arrangement 17 First group 18 Second group 19 Central plane 20 Pockets 21 Mandrel 22 Supporting surfaces 23 Structural elements 24 Fluid connections 25 Flat side 26 Elliptical opening

Claims

1. Electrolysis device (1) for producing gaseous hydrogen, comprising - at least one electrolytic cell (3) extending along a cell axis (2), which is constructed from plate-shaped elements (4) arranged in a row along the cell axis (2), - at least two flow channels (5a, 5b) formed by apertures in the plate-shaped elements (4), the main directions(6a, 6b) of which extend along the cell axis (2), - sealing means (7) for ensuring the tightness of the electrolysis device (1), the sealing means (7) comprising - a first abutment element (8a) and a second abutment element (8b), which abutment elements (8) are spaced apart from one another in the direction of the cell axis (2), - a first pressure plate (9a) and a second pressure plate (9b), which are spaced apart from one another in the direction of the cell axis (2) and are arranged between the first abutment element (8a) and the second abutment element (8b), wherein the at least one electrolytic cell (3) is arranged between the first pressure plate (9a) and the second pressure plate (9b), - at least one retaining element (10), which is configured to retain the first abutment element (8a) and the second abutment element (8b) along the cell axis (2) at a predetermined distance (11), - and at least one elastically deformable pressure element (12) at least between a pair of an abutment element (8) and a pressure plate (9) that are closest to each other, characterized in that at least one elastically deformable pressure element (12a, 12b) is associated with each of the flow channels (5a, 5b), and that a pressure element cross-section (13) projected along the cell axis (2) of at least one of these pressure elements (12a, 12b) is positioned so as to at least partially overlap a flow channel cross-section (14) projected along the cell axis (2).

2. Electrolysis device (1) according to claim 1, characterized in that a pressure element (12a, 12b) is associated with each of the flow channels (5a, 5b) and in that a central axis (15a, 15b) of each of the pressure elements (12a, 12b) is aligned with the main direction (6a, 6b) of the respective flow channels (5a, 5b).

3. Electrolysis device (1) according to any of the preceding claims, characterized in that the flow channels (5a, 5b) are formed by elliptical apertures in the plate-shaped elements (4) and in that each flow channel (5) is associated with two pressure elements (12).

4. Electrolysis device (1) according to any of the preceding claims, characterized in that the flow channels (5) are provided distributed in the circumferential direction of the electrolysis device (1), wherein the normal distance of the central axis (15) of a pressure element (12) associated with the respective flow channel (5) from the cell axis (2) is less than the normal distance of the main direction (6) of the respective flow channel (5) from the cell axis (2).

5. Electrolysis device (1) according to any of the preceding claims, characterized in that the at least one retaining element (10) comprises a guide arrangement (16), by means of which the first pressure plate (9a) and / or the second pressure plate (9b) is guided adjustably relative to the first abutment element (8a) and / or the second abutment element (8b) along the cell axis (2).

6. Electrolysis device (1) according to any of the preceding claims, characterized in that the at least one retaining element (10) comprises a bolt, a pin, a cable or in particular a screw, wherein the at least one retaining element (10) passes through the first and the second pressure plate (9a, 9b) in the direction of the cell axis (2).

7. Electrolysis device (1) according to any of the preceding claims, characterized in that the elastically deformable pressure elements (12) are formed by helical springs and / or disc springs, in particular by equally layered disc springs, wherein a first group (17) of these pressure elements (12) is passed through by a respective retaining element (10) in the direction of the cell axis (2).

8. Electrolysis device (1) according to claim 7, characterized in that a second group (18) of the pressure elements (12) is formed by the pressure elements (12) associated with the flow channels (5), wherein the pressing elements (12) of the second group (18) have a different, in particular a higher pressure force than the pressure elements of the first group (17).

9. Electrolysis device (1) according to any of the preceding claims, characterized in that at least one elastically deformable pressure element (12) is arranged between each of the nearest pairs of an abutment element (8) and a pressure plate (9).

10. Electrolysis device (1) according to claim 9, characterized in that the sealing means (7) is designed asymmetrically with respect to the number and / or configuration of the elastically deformable pressure elements (12) relative to a center plane (19) of the electrolysis device (1) aligned normal to the cell axis (2).

11. Electrolysis device (1) according to any of the preceding claims, characterized in that the at least one elastic pressure element (12) is retained so as to slide in the direction of the cell axis (2) by means of pockets (20) provided in the respective abutment element (8) and / or in the respective pressure plate (9) and / or a mandrel (21) and is retained so as to be positioned relative to the cell axis (2).

12. Electrolysis device (1) according to any of the preceding claims, characterized in that the stiffness of a pressure plate (9) is less than or equal to the stiffness of the abutment element (8) closest to it.

13. Electrolysis device (1) according to any of the preceding claims, characterized in that the pressure plate (9) for the elastic pressure elements (12) includes flat receiving surfaces (22), wherein the receiving surfaces (22) are stiffened by means of web-like structural elements (23).

14. Method for sealing an electrolysis device (1) according to any of the preceding claims, wherein - a first pair of a pressure plate (9) and a nearest abutment element (8) with pressure elements (12) associated with this first pair are pretensioned by means of a pretensioning device and arranged along the cell axis (2), - at least one electrolytic cell (3) made up of plate-shaped elements (4) is lined up next to the first pair along the cell axis (2), - a second pair of a pressure plate (9) and a nearest abutment element (8) with pressure elements (12) associated with this second pair is pretensioned by means of a further pretensioning device and is then lined up next to the at least one electrolytic cell (3) along the cell axis (2), - the abutment element (8) of the first pair is retained at a predetermined distance (11) from the abutment element (8) of the second pair by means of at least one retaining element (10), - each pretensioning device is released from the respective pair of pressure plate (9) and abutment element (8), - and the pre-tensioning force of the sealing means (7) is finely adjusted by means of the at least one retaining element (10), so that the sealing of the plate-shaped elements (4) of the at least one electrolytic cell (3) with respect to its surroundings is achieved.