ELECTROCHEMICAL DEVICE AND METHOD FOR PRODUCING AN ELECTROCHEMICAL DEVICE

Abstract

In order to create an electrochemical device, comprising a plurality of electrochemical units, which succeed one another along a stack direction, wherein each electrochemical unit comprises a bipolar plate and an electrically insulating seal, and a clamping device for clamping the electrochemical units along the stack direction, in which electrochemical device the risk of a short circuit between adjacent bipolar plates is reduced without the expenditure for the production of the electrochemical device being excessively increased, it is proposed that at least one seal of at least one electrochemical unit in the pressed state protrudes laterally beyond a contour of the bipolar plate of the electrochemical unit in a direction of protrusion directed perpendicularly to the stack direction.

Claims

1. An electrochemical device, comprising a plurality of electrochemical units, which succeed one another along a stack direction, wherein each electrochemical unit comprises a bipolar plate and an electrically insulating seal, and a clamping device for pressing together the electrochemical units along the stack direction, wherein at least one seal of at least one electrochemical unit in the pressed state protrudes laterally beyond a contour of the bipolar plate of the electrochemical unit in a direction of protrusion directed perpendicularly to the stack direction.

2. The electrochemical device in accordance with claim 1, wherein at least one seal of at least one electrochemical unit in the pressed state protrudes beyond an outer contour of the bipolar plate of the electrochemical unit into an outside space of the electrochemical device.

3. The electrochemical device in accordance with claim 1, wherein at least one seal of at least one electrochemical unit in the pressed state protrudes beyond an inner contour of the bipolar plate of the electrochemical unit into a medium channel of the electrochemical device.

4. The electrochemical device in accordance with claim 1, wherein at least one seal of at least one electrochemical unit in the pressed state abuts against a seal of an adjacent electrochemical unit.

5. The electrochemical device in accordance with claim 1, wherein at least one outer contour of at least one bipolar plate is shielded from an outside space of the electrochemical device by at least one seal adjacent to the bipolar plate.

6. The electrochemical device in accordance with claim 1, wherein at least one inner contour of at least one bipolar plate is shielded from a medium channel of the electrochemical device by at least one seal adjacent to the bipolar plate.

7. The electrochemical device in accordance with claim 1, wherein the seal in the unpressed state does not protrude laterally beyond the contour of the bipolar plate in a direction of protrusion directed perpendicularly to the stack direction.

8. The electrochemical device in accordance with claim 1, wherein the seal comprises a contact region, which in at least one of the unpressed state and the pressed state abuts against at least one adjacent bipolar plate.

9. The electrochemical device in accordance with claim 8, wherein the contact region in the unpressed state is of asymmetrical configuration in relation to a longitudinal plane of the seal, which extends in parallel to the stack direction and in parallel to a longitudinal direction of the seal through a rounded tip of the contact region.

10. The electrochemical device in accordance with claim 1, wherein the seal comprises an insulating region, which in the pressed state abuts against an insulating region of a further seal of the electrochemical device.

11. The electrochemical device in accordance claim 1, wherein the sealing element has at least one wedge-shaped region.

12. The electrochemical device in accordance with claim 1, wherein the outer faces of the seals of the electrochemical device in the pressed state form a closed outer sealing face on an outer side of the electrochemical device.

13. The electrochemical device in accordance with claim 1, wherein the inner faces of the seals of the electrochemical device in the pressed state form a closed inner sealing face on an inner side of the electrochemical device adjoining a medium channel of the electrochemical device.

14. The electrochemical device in accordance with claim 1, wherein the at least one seal is made of an elastomer material.

15. A method for producing an electrochemical device, comprising the following: forming a stack, which comprises a plurality of electrochemical units succeeding one another along a stack direction, wherein each electrochemical unit comprises a bipolar plate and an electrically insulating seal; and clamping the stack of electrochemical units by means of a clamping device; wherein at least one seal of at least one electrochemical unit in the pressed state protrudes laterally beyond a contour of the bipolar plate of the electrochemical unit in a direction of protrusion directed perpendicularly to the stack direction.

16. The method in accordance with claim 15, wherein at least one seal of at least one electrochemical unit in the unpressed state does not protrude laterally beyond the contour of the bipolar plate in a direction of protrusion directed perpendicularly to the stack direction.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0059] FIG. 1 shows a schematic depiction of an electrochemical device that comprises a plurality of electrochemical units, which succeed one another along a stack direction, and a clamping device for pressing the electrochemical units along the stack direction, wherein each electrochemical unit comprises a bipolar plate and an electrically insulating seal and wherein the seals of the electrochemical units in the pressed state protrude laterally beyond a contour of the bipolar plates of the electrochemical units in a direction of protrusion directed perpendicularly to the stack direction;

[0060] FIG. 2 shows a schematic plan view of one of the bipolar plates of the electrochemical device from FIG. 1;

[0061] FIG. 3 shows a sectional cross section through the electrochemical device from FIG. 1 in the region of an outer contour or an inner contour of the bipolar plates, in a pressed state of the seals after the pressing of the electrochemical units by means of the clamping device;

[0062] FIG. 4 shows a sectional cross section, corresponding to FIG. 3, through the electrochemical device from FIG. 1 in the region of an outer contour or an inner contour of the bipolar plates, in an unpressed state of the seals, before the pressing of the electrochemical units by means of the pressing device;

[0063] FIG. 5 shows a sectional cross section through a second embodiment of the electrochemical device, in which the seals comprise a wedge-shaped region, in a pressed state of the seals, after the pressing of the electrochemical units by means of the clamping device;

[0064] FIG. 6 shows a sectional cross section through a third embodiment of the electrochemical device, in which the seals in the unpressed state do not protrude laterally beyond an outer contour or an inner contour of the bipolar plates, in the unpressed state of the seals, before the pressing of the electrochemical units by means of the clamping device;

[0065] FIG. 7 shows a sectional cross section through a fourth embodiment of the electrochemical device, in which the seals each comprise a wedge-shaped region, a symmetrically formed contact region, and an insulating region, in an unpressed state of the seals, before the pressing of the electrochemical units by means of the clamping device;

[0066] FIG. 8 shows a sectional cross section through a fifth embodiment of the electrochemical device, in which the seals have a wedge-shaped region, an asymmetrical contact region, and an insulating region, in an unpressed state of the seals, before the pressing of the electrochemical units by means of the clamping device;

[0067] FIG. 9 shows a sectional cross section through a sixth embodiment of the electrochemical device, in which the seals have a wedge-shaped region, in an unpressed state of the seals, before the pressing of the electrochemical units by means of the clamping device; and

[0068] FIG. 10 shows a sectional cross section through a seventh embodiment of the electrochemical device, in which the seals have a wedge-shaped region and a contact region, which is of asymmetrical configuration in relation to a plane directed parallel to the stack direction, in an unpressed state of the seals, before the pressing of the electrochemical units by means of the clamping device.

[0069] The same or functionally equivalent elements are provided with the same reference numerals in all Figures.

DETAILED DESCRIPTION OF THE INVENTION

[0070] An electrochemical device, depicted in FIGS. 1 to 4 and denoted as a whole with 100, is configured, e.g., as a fuel cell device or as an electrolyzer.

[0071] The electrochemical device 100 comprises a stack 102, which comprises a plurality of electrochemical units 104 that succeed one another along a stack direction 106.

[0072] Each of the electrochemical units 104 comprises a bipolar plate 108 and an electrically insulating seal 110 as well as an electrochemically active unit (which is not depicted), in which an electrochemical reaction between electrochemically reactive species occurs, which originate from the fluid reaction media fed to the electrochemical device 100, in particular an anode gas and a cathode gas.

[0073] In the pressed state depicted in FIG. 1, the electrochemical units 104 of the electrochemical device 100 are clamped along the stack direction 106 by means of a clamping device 112, which comprises end plates 114 between with the stack 102 of electrochemical units 104 is arranged.

[0074] The end plates 114 may be braced against one another in any manner, for example by means of tie rods.

[0075] Each of the bipolar plates 108 has, as can be best seen in FIG. 2, an outer contour 116 and a plurality of inner contours 118, which each surround a medium through-opening 120 of the bipolar plate 108.

[0076] Each of the medium through-openings 120 forms a constituent part of a respectively associated medium channel 122, which passes through the stack 102 of electrochemical units 104 in parallel to the stack direction 106.

[0077] The medium channels 122 serve to feed fluid media to the electrochemical units 104 or to discharge fluid media from the electrochemical units 104.

[0078] In particular, provision may be made that each one of the medium channels 122 is configured as an anode gas supply channel 124, as a cathode gas supply channel 126, as a cooling medium supply channel 128, as an anode gas discharge channel 130, as a cathode gas discharge channel 132, or as a cooling medium discharge channel 134.

[0079] Each bipolar plate 108 has a respective flow field for each of these fluid media, through which the fluid medium can flow from the respectively associated supply channel to the respectively associated discharge channel, along a flow direction that is directed substantially perpendicularly to the stack direction 106.

[0080] In particular, the bipolar plate 108 may have an anode gas flow field, through which the anode gas can flow from the anode gas supply channel 124 to the anode gas discharge channel 130.

[0081] Further, the bipolar plate 108 may have a cathode gas flow field, through which the cathode gas can flow from the cathode gas supply channel 126 to the cathode gas discharge channel 132.

[0082] Further, the bipolar plate 108 may have a cooling medium flow field, through which the cooling medium can flow from the cooling medium supply channel 128 to the cooling medium discharge channel 134.

[0083] As can be seen best in FIG. 1, the bipolar plates 108 of the electrochemical units 104 are electrically insulated from one another by the respective electrically insulating seals 110 arranged between two bipolar plates 108, such that no short circuit can occur in the electrochemical device 100.

[0084] In the pressed state of the electrochemical units 104 depicted in FIG. 1, the seals 110 in the pressed state protrude laterally beyond the outer contour 116 of the bipolar plate 108 of the same electrochemical unit 104 in a direction of protrusion 136 directed perpendicularly to the stack direction 106.

[0085] In principle, provision may be made that the seals 110 each protrude in the direction of protrusion 136 beyond the outer contour 116 of the respectively associated bipolar plate 108 only over part of their periphery; provision is preferably made, however, that the seals 110 protrude in the direction of protrusion 136 beyond the respectively associated bipolar plate 108 across their entire periphery and across the entire periphery of the outer contour 116 of the respectively associated bipolar plate 108.

[0086] The seals 110 abut with insulating regions 138 that protrude beyond the respectively associated bipolar plate 108 against the seals 110 located above and below in the stack direction 106, such that the outer faces 140 of the seals 110 together form a closed outer sealing face 142 on the outer side of the electrochemical device 100.

[0087] The outer contours 116 of the bipolar plates 108 of the electrochemical units 104 are completely shielded from an outside space 144 of the electrochemical device 100 by this closed outer sealing face 142, such that no conductive elements, in particular no dirt, no foreign particles, and/or no contaminated, for example non-deionized, water is able to contact the bipolar plates 108 from the outside space 144 of the electrochemical device 100.

[0088] A short circuit between two successive bipolar plates 108 in the stack direction 106 due to contamination by such electrically conductive elements from the outside space 144 of the electrochemical device 100 is thereby excluded.

[0089] Further, provision may be made that in the pressed state of the electrochemical units 104 depicted in FIG. 1, the seals 110 protrude laterally in the direction of protrusion 136 directed perpendicularly to the stack direction 106 beyond at least one of the inner contours 118, which each surround a medium through-opening 120 of a medium channel 122 of the electrochemical device 100, of the bipolar plate 108 of the same electrochemical unit 104.

[0090] Both the outer contours 116 of the bipolar plates 108 and the inner contours 118 of the bipolar plates 108 thus form contours 119 of the bipolar plates 108, beyond which the seals 110 in the pressed state can laterally protrude in a direction of protrusion 136 directed perpendicularly to the stack direction 106.

[0091] In principle, provision may be made that the seals 110 each protrude in the direction of protrusion 136 beyond the respective inner contour 118 of the respectively associated bipolar plate 108 only over part of their periphery; provision is preferably made, however, that the seals 110 protrude in the direction of protrusion 136 beyond the respectively associated bipolar plate 108 across their entire inner periphery and across the entire periphery of the respective inner contour 118 of the respectively associated bipolar plate 108.

[0092] Furthermore, the seals 110 abut with insulating regions 138 protruding beyond the respectively associated bipolar plate 108 against the seals 110 located above and below in the stack direction 106, such that the inner faces 140′ of the seals 110 together form a closed inner sealing face 142′ on the inner side of the electrochemical device 100 and on the outer periphery of the respectively associated medium channel 122.

[0093] The inner contours 118 of the bipolar plates 108 of the electrochemical units 104 are completely shielded from the respectively associated medium channel 122 by this closed inner sealing face 142′, such that no conductive elements, in particular no dirt, no foreign particles, and/or no contaminated, for example non-deionized, water is able to contact the bipolar plates 108 from the inside space 144′ of the respectively associated medium channel 122.

[0094] A short circuit between two successive bipolar plates 108 in the stack direction 106 due to contamination by such electrically conductive elements from the inside space 144′ of a medium channel 122 of the electrochemical device 100 is thereby excluded.

[0095] As can be seen in FIG. 4, which shows a sectional cross section through the electrochemical device 100 in the region of an outer contour 116 or in the region of an inner contour 118 of the bipolar plates 108, the bipolar plates 108 may each have a bead 146 in the region in which the seals 110 sealingly abut against the bipolar plates 108.

[0096] The seals 110 each have one or more contact regions 148, with which the seals 110 each abut against an adjacent bipolar plate 108 or against a plurality of adjacent bipolar plates 108.

[0097] For example, each seal 110 may have a first contact region 150, with which the seal abuts against the bead of the bipolar plate 108 of the same electrochemical unit 104, and a second contact region 152, with which the seal 110 abuts against the bipolar plate 108 of the same electrochemical unit 104 and, on a sealing face opposite this bipolar plate 108, against a bipolar plate 108 of an adjacent electrochemical unit 104.

[0098] Adjoining the contact region 148 or the contact regions 148 of the seal 110 is an insulating region 138 of the seal 110, which is arranged on the side of the contact region 148 or the contact regions 148 of the seals facing toward the outside space 144 of the electrochemical device 100 or the inside space 144′ of a medium channel 122 of the electrochemical device 100.

[0099] Arranged on the side of the contact region 148 or contact regions 148 facing away from the insulating region 138 is a respective connection region 156 of the seal 110, by way of which the seal 110 can be connected, for example, to the electrochemically active unit (which is not depicted) of the respective electrochemical unit 104 and/or to a gas diffusion layer of the electrochemical unit 104.

[0100] As can be seen in FIG. 4, which depicts the unpressed state of the seals 110, before the pressing of the electrochemical units 104 by means of the clamping device 112, in this embodiment the seals 110 protrude laterally with their insulating regions 138 beyond the outer contours 116 or beyond the inner contours 118 of the bipolar plates 108 in the direction of protrusion 136 into the outside space 144 or into the inside space 144′ of a medium channel 122 of the electrochemical device 100 already in the unpressed state of the seals 110.

[0101] However, the insulating regions 138 of the seals 110 do not yet contact one another in the unpressed state of the seals 110 depicted in FIG. 4.

[0102] In the pressed state of the seals 110 depicted in FIG. 3, after the pressing of the electrochemical units 104 by means of the clamping device 112, the seals 110 contact one another, such that the closed outer sealing face 142 is formed on the outer side of the electrochemical device 100 or the closed inner sealing face 142′ is formed on a medium channel 122 of the electrochemical device 100.

[0103] A second embodiment of an electrochemical device 100 depicted in FIG. 5 differs from the first embodiment depicted in FIGS. 1 to 4 in that the seals 110 have only one contact region 148, which abuts against two adjacent bipolar plates 108, and a wedge-shaped region 158 of the seals 110 is arranged on the side of the contact region 148 facing away from the insulating region 138.

[0104] In this wedge-shaped region 158, the thickness of the respective seals 110, i.e., the extent thereof along the stack direction 106, increases with decreasing distance from the insulating region 138.

[0105] In this embodiment, the wedge-shaped region 158, the contact region 148, and the insulating region 138 of the seals 110 are of substantially symmetrical configuration in relation to a midplane 160 of the seals 110, which in the assembled state of the electrochemical device 100 run, halfway up the respective seal 110, perpendicularly to the stack direction 106 through the respective seal 110.

[0106] FIG. 5 shows the seals 110 in the unpressed state, before the pressing of the electrochemical units 104 by means of the clamping device 112.

[0107] FIG. 5 shows that, in this embodiment, the seals 110 protrude laterally along the direction of the protrusion 136 beyond the outer contour 116 or beyond the inner contour 118 of the bipolar plates 108 already in the unpressed state and that the insulating regions 138 already contact one another in the unpressed state of the seals 110.

[0108] As a result of the pressing of the electrochemical units 104 by means of the clamping device 112, the contact regions 148 and the insulating regions 138 arranged thereon are moved even further into the outside space 144 of the electrochemical device 100 or into the inside space 144′ of the medium channel 122.

[0109] In all other respects, the second embodiment of an electrochemical device 100 depicted in FIG. 5 corresponds with respect to structure, function, and production method with the first embodiment depicted in FIGS. 1 to 4, to the preceding description of which reference is made in this regard.

[0110] A third embodiment of an electrochemical device 100 depicted sectionally in FIG. 6 differs from the second embodiment depicted in FIG. 5 in that the seals 110 in the unpressed state of the seals 110 depicted in FIG. 6, before the pressing of the electrochemical units 104 by means of the clamping device 112, do not yet protrude laterally in the direction of protrusion 136 beyond the outer contour 116 or beyond the inner contour 118 of the bipolar plates 108.

[0111] During the pressing of the electrochemical units 104, the seals 110 move, however, in the direction of protrusion 136 so far that the overhang of the seals 110 beyond the outer contour 116 or beyond the inner contour 118 of the bipolar plates 108 is achieved during the pressing of the stack 102 of electrochemical units 104.

[0112] In the pressed state of the seals 110 (which is not depicted), the insulating regions 138 of successive seals 110 along the stack direction 106 abut against one another, such that a closed outer sealing face 142 or a closed inner sealing face 142′ is formed in this embodiment, too.

[0113] Furthermore, in this embodiment, the insulating regions 138 of the seals 110 are made so thick in the stack direction 106 that they have contact with both bipolar plates 108 adjacent to the respective seal 110 after the pressing of the electrochemical units 104 by means of the clamping device 112.

[0114] In all other respects, the third embodiment of an electrochemical device 100 depicted in FIG. 6 corresponds with respect to structure, function, and production method with the second embodiment depicted in FIG. 5, to the preceding description of which reference is made in this regard.

[0115] A fourth embodiment of an electrochemical device 100 depicted sectionally in FIG. 7 differs from the third embodiment depicted in FIG. 6 in that, in this embodiment, the seals 110 have two wedge-shaped regions 158 and 158′, between which a contact region 148 of the respective seal 110 is arranged, which is of substantially symmetrical configuration in relation to a longitudinal plane 162 of the seal 110. The longitudinal plane 162 extends in parallel to the outer face 140 of 140′ of the respective seal 110 and in parallel to the stack direction 106, as well as through the rounded tips 163 of the contact region 148, with which the contact region 148 abuts against a respective one of the adjacent bipolar plates 108.

[0116] In the second wedge-shaped region 158′ of the seal 110, the thickness of the seal 110, i.e., the extent thereof along the stack direction 106, decreases with decreasing distance from the insulating region 138 of the seal 110.

[0117] In this embodiment, the insulating region 138 of the seal 110 is configured such that after assembly of the stack 102, but before the pressing of the electrochemical units 104 by means of the clamping device 112, it is not in contact with the adjacent bipolar plates 108.

[0118] However, when pressing the electrochemical units 104, the insulating region 138 is moved beyond the outer contour 116 or beyond the inner contour 118 of the bipolar plates 108 as a result of the movement of the insulating reason 138 caused by the volumetric displacement of the contact region 148 and the wedge-shaped regions 158 and 158′.

[0119] In the pressed state of the seals 110, the insulating regions 138 of successive seals 110 in the stack direction 106 contact one another, and a closed outer sealing face 142 or a closed inner sealing face 142′ is formed, which shields the bipolar plates 108 from the outside space 144 of the electrochemical device 100 or from the inside space 144′ of a medium channel 122 of the electrochemical device 100.

[0120] In this case, the outer edges of the bipolar plates 108 are preferably completely enclosed by the sealing material of the seals 110.

[0121] In all other respects, the fourth embodiment of an electrochemical device 100 depicted in FIG. 7 corresponds with respect to structure, function, and production method with the third embodiment depicted in FIG. 6, to the preceding description of which reference is made in this regard.

[0122] A fifth embodiment of an electrochemical device 100 sectionally depicted in FIG. 8 differs from the fourth embodiment depicted in FIG. 7 in that the second wedge-shaped region 158′ of the seals 110 is omitted and the contact region 148 of the sealing elements 110 is of asymmetrical configuration in relation to the longitudinal plane 162 of the seals 110 running through the rounded tips 163 of the contact region 148.

[0123] In particular, the contact region 148 is configured such that its flank 164 directed toward the insulating region 138 encloses a smaller angle with the stack direction 106 than its flank 166 directed away from the insulating region 138.

[0124] In particular, provision may be made that the flank 164 of the contact region 148 directed toward the insulating region 138 is aligned substantially in parallel to the stack direction 106.

[0125] As a result of this asymmetrical configuration of the contact region 148 of the seals 110, a movement of the sealing material out of the region between the bipolar plates 108 into the outside space 144 of the electrochemical device 100 or into the inside space 144′ of the medium channel 122 when pressing the electrochemical units 104 by means of the clamping device 112 is encouraged.

[0126] In all other respects, the fifth embodiment of the electrochemical device 100 depicted in FIG. 8 corresponds with respect to structure, function, and production method with the fourth embodiment depicted in FIG. 7, to the preceding description of which reference is made in this regard.

[0127] A sixth embodiment of an electrochemical device 100 sectionally depicted in FIG. 9 differs from the fifth embodiment depicted in FIG. 8 in that the seals 110 have no separate insulating region 138 provided in addition to the contact region 148, which is arranged on a side of the contact region 148 facing toward the outside space 144 or the inside space 144′ of the medium channel 122, but instead the contact region 148 itself simultaneously also assumes the function of an insulating region 138 with which the seals 110, in the pressed state of the seals 110, after the pressing of the electrochemical units 104 by means of the clamping device 112, abut against one another in order to improve a closed outer sealing face 142 or a closed inner sealing face 142′.

[0128] The contact region 148 is dimensioned such that during the pressing of the electrochemical units 104, it moves along the direction of protrusion 136 completely or at least partially beyond the outer contour 116 or beyond the inner contour 118 of the bipolar plates 108.

[0129] In the unpressed state of the seals 110 depicted in FIG. 9, the contact region 148 abuts completely against the two adjacent bipolar plates 108.

[0130] In all other respects, the sixth embodiment of the electrochemical device 100 depicted in FIG. 9 corresponds with respect to structure, function, and production method with the fifth embodiment depicted in FIG. 8, to the preceding description of which reference is made in this regard.

[0131] A seventh embodiment of an electrochemical device 100 sectionally depicted in FIG. 10 differs from the sixth embodiment depicted in FIG. 9 in that the seals 110 are of asymmetrical configuration in relation to the midplane 160 of the respective seal 110, which runs, halfway up the respective seal 110, perpendicularly to the stack direction 106 through the respective seal 110.

[0132] In particular, provision may be made that the contact region 148, which simultaneously also assumes the function of an insulating region 138, the wedge-shaped region 158, and the connection region 156 are in, preferably surface-to-surface, contact with the bipolar plate 108 of the same electrochemical unit 104.

[0133] The seals 110 are preferably materially bonded to the bipolar plate 108 of the respective electrochemical unit 104.

[0134] In particular, provision may be made that the seals are produced in situ on the respectively associated bipolar plate 18 by an injection molding process, a pattern printing process, in particular a screen printing process, or by a dispenser application process.

[0135] The bipolar plates 108 may each be of one-piece configuration or comprise a plurality, preferably two or more, bipolar plate layers.

[0136] The contact region 148 of the seals 110 is designed such that during the pressing of the electrochemical units 104 by means of the clamping device 112, it moves along the direction of protrusion 136 beyond the outer contour 116 or the inner contour 118 of the bipolar plates 108 into the outside space 144 of the electrochemical device 100 or into the inside space 144′ of the medium channel 122.

[0137] In all other respects, the seventh embodiment of the electrochemical device 100 depicted in FIG. 10 corresponds with respect to structure, function, and production method with the sixth embodiment depicted in FIG. 9, to the preceding description of which reference is made in this regard.

[0138] The seals 110 described above may each be connected to a bipolar plate 108 or to a plurality of bipolar plates 108, to a gas diffusion layer or to a plurality of gas diffusion layers, to part of an electrochemically active unit, in particular of a membrane electrode arrangement, and/or to another support element.

[0139] The seals 110 are preferably made of an elastomer material.

[0140] The bipolar plates 108 are preferably made of a metallic material.

[0141] The bipolar plates 108 may each be of one-piece configuration and comprise only one single bipolar plate layer or a plurality, in particular two or more, bipolar plate layers.