Electrochemical device, connector unit for contacting an electrochemical device, and combination of an electrochemical device and a connector unit

Abstract

The invention relates to an electrochemical device comprising a stack of multiple electrochemical units which follow one another along a stacking direction, wherein each electrochemical unit comprises a bipolar plate provided with at least one voltage tapping point. In order to provide such an electrochemical device, whose stack of electrochemical units can be electrically contacted in a safe, reliable and robust manner for continuous measurement of the electric potentials of the bipolar plates of the stack, and which is simply constructed, each bipolar plate has at least a first voltage tapping point of a first type and a first voltage tapping point of a second type, and the first voltage tapping point of a first type and the first voltage tapping point of the second type are formed and arranged on the bipolar plate such that they are not symmetrical to each other with respect to a rotation by 180° about an axis of symmetry of the bipolar plate which is parallel to the stacking direction, and, in the stack, the first voltage tapping points of the first type of a plurality of bipolar plates lie one over the other along the stacking direction in a first row and the first voltage tapping points of the second type of a plurality of bipolar plates lie one over the other along the stacking direction in a second row, the first row and the second row of voltage tapping points being mutually adjacent.

Description

[0001] Electrochemical device, plug unit for contacting an electrochemical device and combination of an electrochemical device and a plug unit

[0002] The present invention relates to an electrochemical device comprising a stack of several electrochemical units that follow one another along a stacking direction, wherein each electrochemical unit comprises a bipolar plate that is provided with at least one voltage tapping point.

[0003] The electrochemical units can in particular be designed as fuel cell units, for example as PEM (polymer electrolyte membrane) fuel cell units.

[0004] To monitor and control the operation of such an electrochemical device, it is necessary to be able to continuously measure the electrical potentials or cell voltages at which the bipolar plates of the stack are located during operation of the electrochemical device.

[0005] One challenge is to compensate for both the manufacturing tolerances during the production of the stack of electrochemical units and the relative movements of the bipolar plates of the stack during operation of the electrochemical device.

[0006] The present invention is based on the object of creating an electrochemical device of the type mentioned above, the stack of electrochemical units of which can be electrically contacted in a safe, reliable, and robust manner and is of simple construction for continuous measurement of the electrical potentials of the bipolar plates of the stack. This object is achieved in an electrochemical device according to the preamble of claim 1 in that each bipolar plate has at least one first voltage tapping point of a first type and a first voltage tapping point of a second type.wherein the first voltage tapping point of the first type and the first voltage tapping point of the second type are not formed and arranged symmetrically to one another on the bipolar plate with respect to a rotation of 180° about an axis of symmetry of the bipolar plate parallel to the stacking direction, and wherein in the stack the first voltage tapping points of the first type of a plurality of bipolar plates are arranged one above the other in a first row along the stacking direction, and the first voltage tapping points of the second type of a plurality of bipolar plates are arranged one above the other in a second row along the stacking direction, wherein the first row and the second row of voltage tapping points are arranged adjacent to one another.

[0007] Preferably, all consecutive bipolar plates in the stacking direction of the electrochemical device are configured with an identical geometry. The juxtaposition of the first row and the second row of voltage taps is then achieved by rotating every second bipolar plate in the stack by an angle of 180° around the bipolar plate's axis of symmetry relative to the adjacent first bipolar plates.

[0008] This eliminates the need to provide bipolar plates of different geometries for constructing the stack of electrochemical units, which simplifies the manufacture and storage of the bipolar plates and makes the stacking process simpler and less prone to errors.

[0009] A base body of each bipolar plate preferably exhibits rotational symmetry with respect to a rotation of 180° around the bipolar plate's symmetry axis parallel to the stacking direction. Due to the first voltage tapping points of the first type and the second type, respectively, formed and arranged non-rotationally symmetrically to one another on the bipolar plate, this rotational symmetry present in the base body of the bipolar plate is broken in the bipolar plate supplemented by the voltage tapping points.

[0010] In a preferred embodiment of the invention, it is provided that the voltage tapping points of the first type and the voltage tapping points of the second type are arranged on mutually opposite end faces of the bipolar plate.

[0011] The end faces may be a pair of short sides of a substantially rectangular bipolar plate or a pair of long sides of a substantially rectangular bipolar plate.

[0012] Preferably, the voltage tapping points are each designed as a projection or as a tapping lug.

[0013] In a particularly preferred embodiment of the invention, it is provided that each bipolar plate comprises at least one first voltage tapping point of the first type and at least one second voltage tapping point of the first type, wherein in the stack the first voltage tapping points of the first type of a plurality of bipolar plates lie one above the other in the first row along the stacking direction, the first voltage tapping points of the second type of a plurality of bipolar plates lie one above the other in the second row along the stacking direction, and the second voltage tapping points of the first type of a plurality of bipolar plates lie one above the other in a third row along the stacking direction, wherein the first row and the second row are arranged adjacent to one another and / or the second row and the third row are arranged adjacent to one another.It is preferably provided that the first voltage tapping point of the first type and the second voltage tapping point of the first type are arranged on the same end face of the bipolar plate and that the first voltage tapping point of the second type is arranged on a second end face of the bipolar plate facing away from the first end face.

[0014] Such a design of the electrochemical device makes it possible to arrange the voltage tapping points of the bipolar plates in three or more rows, in each of which voltage tapping points of different bipolar plates lie one above the other along the stacking direction.

[0015] The staggered arrangement of the voltage taps in three or more rows makes it possible to increase the distances between the voltage taps along the stacking direction within the same row.

[0016] This makes it easier to produce a plug unit by means of which these voltage tapping points can be reliably electrically contacted.

[0017] In a further, particularly preferred embodiment of the invention, it is provided that each bipolar plate comprises at least one first voltage tapping point of the first type and one second voltage tapping point of the first type, as well as at least one first voltage tapping point of the second type and one second voltage tapping point of the second type, wherein in the stack, the first voltage tapping points of the first type of several bipolar plates are arranged one above the other along the stacking direction in the first row, the first voltage tapping points of the second type of several bipolar plates are arranged one above the other along the stacking direction in the second row, the second voltage tapping points of the first type of several bipolar plates are arranged one above the other along the stacking direction in a third row, and the second voltage tapping points of the second type of several bipolar plates are arranged one above the other in a fourth row,wherein the first row and the second row and / or the second row and the third row and / or the third row and the fourth row are arranged adjacent to each other.,

[0018] This design of the electrochemical device makes it possible to arrange the electrically contactable voltage tapping points of the bipolar plates in four or more rows of voltage tapping points, which are arranged one above the other along the stacking direction.

[0019] Preferably, all bipolar plates in the stack of electrochemical units are designed identically to one another.

[0020] The first voltage tapping points of the first type and the second voltage tapping points of the first type are preferably arranged on the same end face of the bipolar plate, while the first voltage tapping points of the second type and the second voltage tapping points of the second type are preferably arranged on a second end face of the bipolar plate facing away from the first end face.

[0021] Generally speaking, it can be provided that each bipolar plate comprises at least n voltage tapping points of the first type and at least m voltage tapping points of the second type, wherein in the stack the i-th voltage tapping points of the first type of several bipolar plates are arranged one above the other in a row along the stacking direction, with i = 1 to n, and the j-th voltage tapping points of the second type of several bipolar plates are arranged one above the other in a row along the stacking direction, with j = 1 to m.

[0022] In a particular embodiment of the invention, it is provided that no row in which voltage tapping points of the first type are arranged one above the other is arranged adjacent to a row in which (other) voltage tapping points of the first type are arranged one above the other. The present invention further relates to a plug unit for contacting voltage tapping points of an electrochemical device according to one of claims 1 to 7, which comprises a plurality of electrochemical units arranged one after the other along a stacking direction.

[0023] Such a plug unit comprises a housing which has a plurality of receptacles for receiving a respective voltage tapping point of the electrochemical device, wherein at least one of the receptacles is designed as a contact receptacle in which, in the assembled state of the plug unit, an electrically conductive connection is established with the respective voltage tapping point received in the contact receptacle by means of an electrically conductive contact element.

[0024] In particular, when the electrochemical device, for the contacting of which the plug unit is provided, comprises more than two rows of voltage tapping points arranged one above the other along the stacking direction, preferably at least one of the receptacles of the plug unit is designed as a dummy receptacle in which, in the assembled state of the plug unit, no electrically conductive connection is established with the voltage tapping point respectively accommodated in the dummy receptacle.

[0025] The receptacles of the plug unit are preferably arranged in a plurality of rows extending along a longitudinal direction of the plug unit and in a plurality of rows extending transversely to the longitudinal direction of the plug unit.

[0026] In the assembled state of the plug unit, in which the plug unit accommodates voltage taps of the electrochemical device, the longitudinal direction of the plug unit is preferably aligned parallel to the stacking direction of the electrochemical device. Preferably, only one contact receptacle is arranged in each row of the plug unit. This ensures that at most one voltage tap point of each bipolar plate of the stack is electrically contacted by the plug unit.

[0027] If the plug unit is provided with dummy receptacles for voltage tapping points of the electrochemical device, in which no electrically conductive connection is established with the voltage tapping point accommodated in the dummy receptacle when the plug unit is mounted, the extent of at least one dummy receptacle along the longitudinal direction of the plug unit is preferably smaller than the extent of a contact receptacle of the plug unit along the longitudinal direction of the plug unit. In this way, the plug unit can be designed more compactly.

[0028] Furthermore, it can be provided that the receptacles of at least two rows of receptacles of the plug unit - seen in the longitudinal direction of the plug unit - overlap each other.

[0029] The electrochemical device according to the invention and the plug unit according to the invention are particularly suitable for use in a combination of an electrochemical device according to the invention and at least one plug unit according to the invention.

[0030] It is preferably provided that at most one voltage tapping point of each bipolar plate of the electrochemical device is accommodated in a contact receptacle of a plug unit, in which, in the assembled state of the plug unit, an electrically conductive connection is established with the voltage tapping point accommodated in the contact receptacle by means of an electrically conductive contact element. Further features and advantages of the invention are the subject of the following description and the drawings of exemplary embodiments.

[0031] The drawings show:

[0032] Fig. 1 is a schematic side view of an electrochemical device comprising a stack of several electrochemical units arranged one after the other along a stacking direction (Z-direction) of the electrochemical device, each electrochemical unit comprising a bipolar plate each provided with several voltage tapping points, each bipolar plate having a first voltage tapping point of a first type and a first voltage tapping point of a second type,wherein the first voltage tapping point of the first type and the first voltage tapping point of the second type are not formed and arranged symmetrically to one another on the bipolar plate with respect to a rotation of 180° about an axis of symmetry of the bipolar plate parallel to the stacking direction, and wherein in the stack the first voltage tapping points of the first type of a plurality of bipolar plates lie one above the other in a first row along the stacking direction, and the first voltage tapping points of the second type of a plurality of bipolar plates lie one above the other in a second row along the stacking direction, wherein the first row and the second row of voltage tapping points are arranged adjacent to one another, and wherein the voltage tapping points are at least partially received in contact receptacles of an electrical plug unit;

[0033] Fig. 2 is a top plan view of the electrochemical device from Fig. 1, taken along the stacking direction of the electrochemical device, without the plug unit arranged thereon; Fig. 3 is a schematic top plan view of one of the bipolar plates of the electrochemical device from Figs. 1 and 2, taken along the stacking direction (Z direction);

[0034] Fig. 4 is an enlarged view of the plug unit from Fig. 1, without the voltage tapping points of the electrochemical device accommodated in the receptacles of the plug unit in Fig. 1;

[0035] Fig. 5 is a schematic plan view from above of the plug unit of Fig. 4, looking in the direction of arrow 5 in Fig. 4;

[0036] Fig. 6 is a representation corresponding to Fig. 1 of a second embodiment of an electrochemical device, in which each bipolar plate has a first voltage tapping point of a first type and a second voltage tapping point of the first type as well as a first voltage tapping point of a second type, wherein all voltage tapping points of a bipolar plate are not formed and arranged symmetrically to one another on the bipolar plate with respect to a rotation of 180° about an axis of symmetry of the bipolar plate parallel to the stacking direction, and wherein in the stack of electrochemical units, the first voltage tapping points of the first type of several bipolar plates lie one above the other in a first row along the stacking direction,the first voltage tapping points of the second type of a plurality of bipolar plates lie one above the other in a second row along the stacking direction, and the second voltage tapping points of the first type of a plurality of bipolar plates lie one above the other in a third row along the stacking direction, wherein the first row and the second row are arranged adjacent to one another, the second row and the third row are arranged adjacent to one another, and the second row is arranged between the first row and the third row, wherein the voltage tapping points of a plurality of superimposed bipolar plates are accommodated in contact receptacles or in dummy receptacles of a plug unit, wherein the plug unit has a first row of receptacles, a second row of receptacles, and a third row of receptacles,wherein the rows extend parallel to the stacking direction of the electrochemical device and the receptacles of the plug unit are further arranged in rows extending transversely to the stacking direction, said rows alternately comprising a contact receptacle or a contact receptacle and a dummy receptacle;

[0037] Fig. 7 is a schematic plan view of the electrochemical device of Fig. 6 corresponding to Fig. 2, without the plug unit shown in Fig. 6;

[0038] Fig. 8 is a schematic plan view of a bipolar plate of the electrochemical device of Figs. 6 and 7;

[0039] Fig. 9 is an enlarged view of the plug unit from Fig. 6;

[0040] Fig. 10 is a schematic plan view of the plug unit of Fig. 9, looking in the direction of arrow 10 in Fig. 9;

[0041] Fig. 11 is a schematic representation of a third embodiment of an electrochemical device corresponding to Figs. 1 and 6, in which each bipolar plate has a first voltage tapping point of a first type, a second voltage tapping point of the first type, a first voltage tapping point of a second type, and a second voltage tapping point of the second type, wherein all voltage tapping points of the bipolar plate are not formed and arranged symmetrically to one another on the bipolar plate with respect to a rotation of 180° about an axis of symmetry of the bipolar plate parallel to the stacking direction, and wherein, in the stack of electrochemical units, the first voltage tapping points of the first type of several bipolar plates are arranged one above the other in a first row along the stacking direction, and the first voltage tapping points of the second type of several bipolar plates are arranged one above the other in a second row along the stacking direction,the second voltage tapping points of the first type of a plurality of bipolar plates are arranged one above the other in a third row along the stacking direction, and the second voltage tapping points of the second type of a plurality of bipolar plates are arranged one above the other in a fourth row along the stacking direction, wherein the first row and the second row are arranged adjacent to one another, the second row and the third row are arranged adjacent to one another, and the third row and the fourth row are arranged adjacent to one another, and wherein the second row is arranged between the first row and the third row and the third row is arranged between the second row and the fourth row, wherein the voltage tapping points of a plurality of bipolar plates are accommodated in the receptacles of a plug unit, wherein the plug unit comprises a first row of receptacles, a second row of receptacles, a third row of receptacles, and a fourth row of receptacles,which each extend along a longitudinal direction of the plug unit, which in the assembled state of the plug unit is aligned parallel to the stacking direction of the electrochemical device, and wherein the receptacles of the plug unit are arranged in rows extending transversely to the longitudinal direction of the plug unit, wherein the rows following one another in the longitudinal direction of the plug unit each comprise a contact receptacle and a dummy receptacle, and the contact receptacles of rows following one another in the longitudinal direction of the plug unit are each offset from one another by one row;,

[0042] Fig. 12 is a schematic plan view of the electrochemical device of Fig. 11, without the plug unit shown in Fig. 11;

[0043] Fig. 13 is a schematic plan view of a bipolar plate of the electrochemical device of Figs. 11 and 12;

[0044] Fig. 14 is an enlarged view of the plug unit from Fig. 11, the receptacles of which are arranged in four rows extending along a longitudinal direction of the plug unit and in twelve rows extending transversely to the longitudinal direction of the plug unit, wherein each row of the plug unit comprises a contact receptacle and a dummy receptacle, and wherein the contact receptacles of successive rows in the longitudinal direction of the plug unit are offset from one another by one row; and

[0045] Fig. 15 is a schematic plan view of the plug unit of Fig. 14, viewed along arrow 15 in Fig. 14.

[0046] Identical or functionally equivalent elements are designated by the same reference numerals in all figures.

[0047] A first embodiment of a combination, designated as a whole by 100, comprising an electrochemical device 102 and a plug unit 104 for contacting voltage tapping points 106 of the electrochemical device 102 is shown in Figs. 1 to 5. The electrochemical device 100 comprises a stack 108 of electrochemical units arranged one after the other along a stacking direction 110.

[0048] The stacking direction 110 is also referred to below as the Z-direction of the electrochemical device 102.

[0049] The stack 108 can be designed, for example, as a fuel cell stack, in particular as a PEM (polymer electrolyte membrane) fuel cell stack.

[0050] Each of the electrochemical units of the stack 108 comprises a bipolar plate 112 and other components which are not shown individually in the drawings.

[0051] These further components may in particular comprise an electrochemically active unit, for example a membrane electrode assembly, gas diffusion layers and seals, for example elastomer seals.

[0052] These additional components electrically insulate two bipolar plates 112 that directly follow one another in the stack 108 along the stacking direction 110.

[0053] During operation of the electrochemical device 102, each of the electrically conductive bipolar plates 112 is at an electrical potential that is different from the electrical potential of the adjacent bipolar plates 112.

[0054] These electrical potentials or cell voltages at which the various bipolar plates 112 of the stack 108 are located are continuously monitored during operation of the electrochemical device 102 in order to control the electrochemical device 102 with the greatest possible power efficiency and to detect any malfunctions in the operation of the electrochemical device 102 as soon as possible. In order to be able to tap the electrical potentials or cell voltages of the bipolar plates 112 in a simple and reliable manner during operation of the electrochemical device 100, the combination 100 comprises, in addition to the electrochemical device 102, at least one plug unit 104 (see FIGS. 1, 4, and 5), which comprises an electrically insulating housing 114 and a plurality of electrically conductive contact elements 116 arranged in the housing 114.

[0055] As best seen in Figs. 1 to 3, each of the bipolar plates 112 of the stack 108 includes a first voltage tap 106a of a first type and a first voltage tap 106a' of a second type.

[0056] As can be seen from Fig. 3, which shows a plan view along the stacking direction 110 of an individual bipolar plate 112 of the stack 108, a base body 117 of the bipolar plate 112 without the voltage tapping points 106a, 106a' is rotationally symmetrical with respect to a rotation of 180° about an axis of symmetry 118 of the base body 117 of the bipolar plate 112 aligned parallel to the stacking direction 110.

[0057] As can best be seen from Fig. 2, which shows a plan view along the stacking direction 110 of the stack 108 of the electrochemical device 102, the first voltage tapping point 106a of the first type and the first voltage tapping point 106a' of the second type are not formed and arranged symmetrically to one another on the bipolar plate 112 with respect to a rotation of 180° about the symmetry axis 118 of the bipolar plate 112 parallel to the stacking direction 110.

[0058] In the stack 108, bipolar plates 112 following one another along the stacking direction 110 are each rotated relative to one another by 180° about the axis of symmetry 118, so that the next but one bipolar plates 112 are each congruently arranged one above the other along the stacking direction 110, while the bipolar plates 112 arranged between two congruently arranged bipolar plates 112 are rotated by an angle of 180° about the axis of symmetry 118 of the bipolar plates 112 relative to these congruently arranged bipolar plates 112.

[0059] Due to this structure of the stack 108, in the stack 108, the first voltage tapping points 106a of the first type of a plurality of bipolar plates 112 are arranged one above the other in a first row 120a along the stacking direction 110, and the first voltage tapping points 106a' of the second type of a plurality of bipolar plates 112 of the stack 108 are arranged one above the other in a second row 120b along the stacking direction 110, wherein the first row 120a of voltage tapping points 106a and the second row 120b of voltage tapping points 106a' are arranged adjacent to one another, and wherein the voltage tapping points 106a of the first row 120a, on the one hand, and the voltage tapping points 106a' of the second row 120b, on the other hand, are arranged in a direction perpendicular to the stacking direction 110 and perpendicular to a contacting direction 122 of the voltage tapping points 106a, 106a' aligned offset direction 124 are offset from each other.

[0060] The offset direction 124 is also referred to as the X direction below.

[0061] The contacting direction 122 is the direction along which the voltage tapping points 106a, 106a' protrude relative to the respective voltage tapping point 106a, 106a' adjacent edge sections 126 of the bipolar plate 112.

[0062] The contacting direction 122 is also referred to below as the Y-direction. The first row 120a and the second row 120b of voltage taps 106 are both arranged on a first side 128a of the stack 108, preferably in a first half 130a of two halves 130a and 130b, into which the stack is divided by a longitudinal center plane 134 of the stack 108 extending parallel to the stacking direction and perpendicular to an edge 132 of the bipolar plates 112 through the axis of symmetry 118 of the bipolar plates 112.

[0063] On a second side 128b opposite the first side 128a of the stack 108, a further first row 120a', which is formed from first voltage tapping points 106a of the first type of a plurality of bipolar plates 112, and a further second row 120b', which is formed from first voltage tapping points 106a' of the second type of a plurality of bipolar plates 112, are arranged.

[0064] The further first row 120a' of voltage taps 106a and the further second row 120b' of voltage taps 106a' are preferably arranged in the second half 130b of the stack 108.

[0065] The further first row 120a' and the further second row 120b' of voltage tapping points 106 are redundant to the first row 120a of voltage tapping points 106a and to the second row 120b of voltage tapping points 106a', because for monitoring the potentials or cell voltages of the electrochemical units of the electrochemical device 102 it is sufficient if each bipolar plate 112 can be contacted at only one voltage tapping point 106 by a plug unit 104.

[0066] The further first row 120a' and the further second row 120b' of voltage tapping points 106 will therefore not be discussed further in the following description. As best seen in Fig. 1, the offset arrangement of the voltage tapping points 106 of the first row 120a and the second row 120b of voltage tapping points 106 along the X direction results in the distance between two voltage tapping points 106 arranged directly one above the other in the stacking direction 110 being increased to twice the distance that these voltage tapping points 106 would have without the distribution of the voltage tapping points 106 across multiple rows 120a, 120b of voltage tapping points 106.

[0067] This creates more space between the voltage tapping points 106 located directly above one another to accommodate contact elements 116 and housing components of the plug unit 104.

[0068] Each bipolar plate 112 may comprise several, for example two, bipolar plate layers, for example a first bipolar plate layer and a second bipolar plate layer.

[0069] The first bipolar plate layer and the second bipolar plate layer are connected to each other in a fluid-tight manner at joining lines (not shown) in order to form medium chambers and medium channels between them.

[0070] Each of the voltage tapping points 106 of the bipolar plate 112 is preferably formed in two layers, wherein a first voltage tapping part is formed integrally with a main body of the first bipolar plate layer and a second voltage tapping part is formed integrally with a main body of the second bipolar plate layer.

[0071] Alternatively, however, it can also be provided that the voltage tapping points 106 are each formed as a single layer, wherein the single-layer voltage tapping point 106 is then preferably formed integrally with a main body of the first bipolar plate layer or integrally with a main body of the second bipolar plate layer. Alternatively to a one-piece design with a main body of a bipolar plate layer, it can also be provided that the voltage tapping points 106 are formed separately from a main body of a bipolar plate layer and subsequently connected to a main body of a bipolar plate layer, preferably by means of a material bond, for example by welding, in particular by laser welding.

[0072] If a voltage tapping point 106 is formed in two layers, it is preferably provided that the two layers of the voltage tapping point are connected to one another in a materially bonded manner, for example by welding along a welding line.

[0073] The first bipolar plate layer may be an anode-side bipolar plate layer that defines a flow field (not shown) for an anode gas of the electrochemical device 102.

[0074] In this case, the second bipolar plate layer is a cathode-side bipolar plate layer which defines a flow field (not shown) for a cathode gas of the electrochemical device 102.

[0075] As can best be seen from Figures 1 and 4, the plug unit 104, by means of which the voltage tapping points 106 of the first row 120a and the second row 120b can be electrically contacted, comprises a plurality of rows 136a and 136b, in the illustrated embodiment two, of contact receptacles 138, which extend along a longitudinal direction 140 of the plug unit 104, wherein the longitudinal direction 140 of the plug unit 104 is aligned parallel to the stacking direction 110 of the stack 108 of the electrochemical device 102 in the assembled state of the plug unit 104.

[0076] The contact receptacles 138 are offset from one another in the offset direction 124 (X-direction) running perpendicular to the stacking direction 110, in the same manner and to the same extent as the voltage tapping points 106a, 106a' of the first row 120a and the second row 120b of voltage tapping points 106 of the stack 108 are offset relative to one another, so that each voltage tapping point 106a, 106a' of the first row 120a and the second row 120b can be inserted into one of the contact receptacles 138 of the plug unit 104.

[0077] In each of the contact receptacles 138 of the plug unit 104, a contact element 116 is arranged, by means of which a voltage tapping point 106 accommodated in the contact receptacle 138 can be electrically conductively contacted.

[0078] The contact elements 116 can each be formed in one or more parts.

[0079] Preferably, the contact elements 116 comprise a spring-elastic metallic material.

[0080] It is preferably provided that the contact elements 116 have a form elasticity, by means of which a contact force is generated with which the contact elements 116 bear against the respectively assigned voltage tapping point 106.

[0081] In the assembled state of the plug unit 104, each row 136a, 136b of contact receptacles 138 electrically conductively contacts every second of the bipolar plates 112 following one another in the stacking direction 110 of the stack 108 of electrochemical units.

[0082] Electrical lines (not shown) can be arranged on the housing 114 of the plug unit 104, which electrically connect each of the contact elements 116 of the contact receptacles 138 to a contact pin of a plug connection (not shown) of the plug unit 104.

[0083] To such a plug connection (not shown) of the plug unit 104, a plug connection of a connecting cable (not shown) which is designed to complement this can be connected, by means of which an electrically conductive connection can be established between the contact elements 116 of the contact receptacles 138 of the plug unit 104 on the one hand and the inputs of a monitoring device (not shown) of the electrochemical device 102.

[0084] This monitoring device may form part of a control device of the electrochemical device 102, which controls the operation of the electrochemical device 102 depending on the respectively determined electrical potentials or cell potentials of the bipolar plates 112 in the stack 108 of electrochemical units.

[0085] The housing 114 of the plug unit 104 is preferably formed from an electrically insulating plastic material.

[0086] For example, the housing 114 of the plug unit 104 may be formed from a polyamide material.

[0087] The housing 114 of the plug unit 104 can be formed in one or more parts.

[0088] The housing 114 or parts of the housing 114 of the plug unit can be manufactured, for example, by an injection molding process.

[0089] A second embodiment of a combination 100 comprising an electrochemical device 102 and a plug unit 104, shown in Figs. 6 to 10, differs from the first embodiment described above in that each bipolar plate 112 has a first voltage tapping point 106a of the first type and a second voltage tapping point 106b of the first type, as well as a first voltage tapping point 106a' of the second type. As can best be seen from Fig. 8, the first voltage tapping point 106a of the first type and the second voltage tapping point 106b of the first type are arranged on a first end face 144a of the bipolar plate 112, while the first voltage tapping point 106a' of the second type is arranged on a second end face 144b of the bipolar plate 112 opposite the first end face 144 of the bipolar plate 112.

[0090] The first voltage tapping point 106a of the first type and the second voltage tapping point 106b of the first type are arranged in a first half 146a of the bipolar plate 112, wherein the first half 146a of the bipolar plate 112 is separated from a second half 146b of the bipolar plate 112 by a longitudinal center plane 148 of the bipolar plate 112, which runs parallel to the stacking direction 110 and perpendicular to the edges of the bipolar plate 112 at the end faces 144a, 144b thereof through the axis of symmetry 118 of the bipolar plate 112.

[0091] A distance d between the first voltage tapping point 106a of the first type and the second voltage tapping point 106b of the first type along the offset direction 124 (X-direction) is greater than the greatest extent D of the first voltage tapping point 106a' of the second type along the offset direction 124, so that the first voltage tapping point 106a' of the second type of a second bipolar plate 112 following the first bipolar plate 112 in the stacking direction 110 - when viewed along the stacking direction 110 - fits between the first voltage tapping point 106a of the first type and the second voltage tapping point 106b of the first type of the first bipolar plate 112 when the second bipolar plate 112 is rotated by an angle of 180° about the symmetry axis 118 of the bipolar plate 112 relative to the first Bipolar plate 112 is arranged in the stack 108, as can be seen in Fig. 7.

[0092] All voltage tapping points 106a, 106b, 106a' of a bipolar plate 112 are not formed and arranged symmetrically to one another on the bipolar plate 112 with respect to a rotation of 180° about the axis of symmetry 118 of the bipolar plate 112 parallel to the stacking direction 110. As can be seen from Figs. 6 and 7, in the stack 108 of electrochemical units, the first voltage tapping points 106a of the first type of a plurality of bipolar plates 112 are arranged one above the other along the stacking direction 110 in a first row 120a, while the first voltage tapping points 106a' of the second type of a plurality of bipolar plates 112 are arranged one above the other along the stacking direction 110 in a second row 120b, and the second voltage tapping points 106b of the first type of a plurality of bipolar plates 112 are arranged one above the other along the stacking direction 110 in a third row 120c.

[0093] The first row 120a and the second row 120b of voltage tapping points 106 are arranged adjacent to one another, the second row 120b and the third row 120c of voltage tapping points 106 are arranged adjacent to one another, and the second row 120b of voltage tapping points 106 is arranged between the first row 120a and the third row 120c of voltage tapping points 106.

[0094] As can best be seen from Fig. 6, the voltage tapping points 106 of several superimposed bipolar plates 112 are accommodated in contact receptacles 138 or in dummy receptacles 150 of a plug unit 104.

[0095] The plug unit 104 has a first row 136a of receptacles, a second row 136b of receptacles, and a third row 136c of receptacles, wherein these rows 136a, 136b, and 136c extend parallel to the stacking direction 110 of the electrochemical device 102 in the assembled state of the plug unit 104, and the receptacles of the plug unit 104 are further arranged in rows 152a, 152b, 152c, and 152d extending transversely to the stacking direction 110, wherein the rows 152a of the first type each comprise only one contact receptacle 138 in the second row 136b, the rows 152b of the second type each comprise a dummy receptacle 150 in the first row 136a and each comprise a contact receptacle 138 in the third row 136c,the rows 152c of the third type each comprise only one contact receptacle 138 in the second row 136b, and the rows 152d of the fourth type each comprise one contact receptacle 138 in the first row 136a and one dummy receptacle 150 in the third row 136c.

[0096] The rows 152a of the first type, the rows 152b of the second type, the rows 152c of the third type and the rows 152d of the fourth type are arranged alternately in the longitudinal direction 140 of the plug unit 104.

[0097] This design of the plug unit 104 ensures that the plug unit 104 electrically contacts each of the bipolar plates 112 only at a single voltage tapping point 106.

[0098] The dummy receptacles 150 differ from the contact receptacles 138 of the plug unit 104 in that they do not comprise a contact element 116 for electrically conductive contact with a voltage tapping point 106 of the electrochemical device 102 arranged in the respective receptacle.

[0099] Therefore, the dummy receptacles 150 can have a smaller extension than the contact receptacles 138 in the longitudinal direction 140 of the plug unit 104, which is aligned parallel to the stacking direction 110 in the assembled state of the plug unit 104.

[0100] Otherwise, the second embodiment of a combination 100 comprising an electrochemical device 102 and a plug unit 104 shown in Figs. 6 to 10 corresponds in terms of structure, function, and method of manufacture to the first embodiment shown in Figs. 1 to 5, to the above description of which reference is made in this regard. A third embodiment of a combination 100 comprising an electrochemical device 102 and a plug unit 104 shown in Figs. 11 to 15 differs from the second embodiment described above in that each bipolar plate 112 has a first voltage tapping point 106a of the first type, a second voltage tapping point 106b of the first type, a first voltage tapping point 106a' of the second type, and a second voltage tapping point 106b' of the second type.

[0101] As can best be seen from Fig. 13, the first voltage tapping point 106a of the first type and the second voltage tapping point 106b of the first type are arranged on a first end face 144a of the bipolar plate 112, while the first voltage tapping point 106a' of the second type and the second voltage tapping point 106b' of the second type are arranged on a second end face 144b of the bipolar plate 112 opposite the first end face 144 of the bipolar plate 112.

[0102] The first voltage tapping point 106a of the first type and the second voltage tapping point 106b of the first type are arranged in a first half 146a of the bipolar plate 112, wherein the first half 146a of the bipolar plate 112 is separated from a second half 146b of the bipolar plate 112 by a longitudinal central axis 148 of the bipolar plate 112, which runs parallel to the stacking direction 110 and perpendicular to the edges of the bipolar plate 112 at the end faces 144a, 144b thereof through the axis of symmetry 118 of the bipolar plate 112.

[0103] A distance d between the first voltage tapping point 106a of the first type and the second voltage tapping point 106b of the first type along the offset direction 124 (X-direction) is greater than the greatest extent D of the first voltage tapping point 106a' of the second type along the offset direction 124, so that the first voltage tapping point 106a' of the second type of a second bipolar plate 112 following the first bipolar plate 112 in the stacking direction 110 - when viewed along the stacking direction 110 - fits between the first voltage tapping point 106a of the first type and the second voltage tapping point 106b of the first type of the first bipolar plate 112 when the second bipolar plate 112 is rotated by an angle of 180° about the symmetry axis 118 of the bipolar plate 112 relative to the first bipolar plate 112 is arranged in the stack 108, as can be seen in Fig. 12.

[0104] Furthermore, a distance d between the first voltage tapping point 106a' of the second type and the second voltage tapping point 106b' of the second type along the offset direction 124 (X-direction) is greater than the greatest extent D of the second voltage tapping point 106b of the first type along the offset direction 124, so that the second voltage tapping point 106b of the first type of a first bipolar plate 112 fits between the first voltage tapping point 106a' of the second type and the second voltage tapping point 106b' of the second type of a second bipolar plate 112 following the first bipolar plate 112 - when viewed along the stacking direction 110 - when the second bipolar plate 112 is rotated by an angle of 180° about the symmetry axis 118 of the bipolar plate 112 relative to the first bipolar plate 112 in the stack 108 is arranged, as can be seen in Fig. 12.

[0105] All voltage tapping points 106a, 106b, 106a' and 106b' of a bipolar plate 112 are not formed and arranged symmetrically to one another on the bipolar plate 112 with respect to a rotation of 180° about the axis of symmetry 118 of the bipolar plate 112 parallel to the stacking direction 110.

[0106] As can be seen from Figs. 11 and 12, in the stack 108 of electrochemical units, the first voltage tapping points 106a of the first type of a plurality of bipolar plates 112 are arranged one above the other along the stacking direction 110 in a first row 120a, while the first voltage tapping points 106a' of the second type of a plurality of bipolar plates 112 are arranged one above the other along the stacking direction 110 in a second row 120b, the second voltage tapping points 106b of the first type of a plurality of bipolar plates 112 are arranged one above the other along the stacking direction 110 in a third row 120c, and the second voltage tapping points 106b' of the second type of a plurality of bipolar plates 112 are arranged one above the other along the stacking direction 110 in a fourth row 120b.

[0107] The first row 120a and the second row 120b of voltage tapping points 106 are arranged adjacent to one another, the second row 120b and the third row 120c of voltage tapping points 106 are arranged adjacent to one another, and the third row 120b and the fourth row 120d of voltage tapping points 106 are arranged adjacent to one another.

[0108] The second row 120b of voltage tapping points 106 is arranged between the first row 120a and the third row 120c of voltage tapping points 106.

[0109] The third row 120c of voltage tapping points 106 is arranged between the second row 120b and the fourth row 120d of voltage tapping points 106.

[0110] As can best be seen from Fig. 11, the voltage tapping points 106 of several superimposed bipolar plates 112 are accommodated in contact receptacles 138 or in dummy receptacles 150 of a plug unit 104.

[0111] The plug unit 104 has a first row 136a of receptacles, a second row 136b of receptacles, a third row 136c of receptacles and a fourth row 136b of receptacles, wherein these rows 136a, 136b, 136c and 136d extend parallel to the stacking direction 110 of the electrochemical device 102 in the assembled state of the plug unit 104 and the receptacles of the plug unit 104 are further arranged in rows 152a, 152b, 152c and 152d running transversely to the stacking direction 110, wherein the rows 152a of the first type each comprise a dummy receptacle 150 in the second row 136b of receptacles and a contact receptacle 138 in the fourth row 136d of receptacles, the rows 152b of the second type each comprise a dummy receptacle 150 in the first row 136a of receptacles and a contact receptacle 138 in the third row 136c of receptacles,the rows 152c of the third type each comprise a contact receptacle 138 in the second row 136b of receptacles and a dummy receptacle 150 in the fourth row 136d of receptacles, and finally the rows 152d of the fourth type each comprise a contact receptacle 138 in the first row 136a of receptacles and a dummy receptacle 150 in the third row 136c of receptacles.

[0112] The rows 152a of the first type, the rows 152b of the second type, the rows 152c of the third type and the rows 152d of the fourth type are arranged alternately in the longitudinal direction 140 of the plug unit.

[0113] This design of the plug unit 104 ensures that the plug unit 104 electrically contacts each of the bipolar plates 112 only at a single voltage tapping point 106.

[0114] As in the second embodiment shown in Figs. 6 to 10, the dummy receptacles 150 differ from the contact receptacles 138 of the plug unit 104 in that they do not comprise a contact element 116 for electrically conductive contacting of a voltage tapping point 106 of the electrochemical device 102 arranged in the respective receptacle.

[0115] Therefore, the dummy receptacles 150 can have a smaller extent than the contact receptacles 138 in the longitudinal direction 140 of the plug unit 104, which in the assembled state of the plug unit 104 is aligned parallel to the stacking direction 110. As can be seen from Fig. 11, the dummy receptacles 150 and / or the contact receptacles 138 of one of the rows 152a of the first type, the rows 152b of the second type, the rows 152c of the third type and / or the rows 152d of the fourth type - viewed in the longitudinal direction 140 of the plug unit 104 - can each engage with a contact receptacle 138 and / or with a dummy receptacle 150 of an adjacent row 152b of the second type, an adjacent row 152c of the third type, an adjacent row 152d of the fourth type or an adjacent row 152a of the first type. overlap.

[0116] As a result, the plug unit 104 can be designed to be more compact in a transverse direction 154 of the plug unit 104 which is perpendicular to the longitudinal direction 140 of the plug unit 104 and which is preferably also oriented perpendicular to the contacting direction 122 of the voltage tapping points 106 accommodated in the receptacles of the plug unit 104.

[0117] Otherwise, the third embodiment of a combination 100 of an electrochemical device 102 and a plug unit 104 shown in Figs. 11 to 15 corresponds in terms of structure, function and method of manufacture to the second embodiment shown in Figs. 6 to 10, to the above description of which reference is made in this respect.

Claims

Patent claims 1. An electrochemical device comprising a stack (108) of a plurality of electrochemical units following one another along a stacking direction (110), each electrochemical unit comprising a bipolar plate (112) provided with at least one voltage tapping point (106), characterized in that each bipolar plate (112) has at least one first voltage tapping point (106a) of a first type and a first voltage tapping point (106a') of a second type,wherein the first voltage tapping point (106a) of the first type and the first voltage tapping point (106a') of the second type are not formed and arranged symmetrically to one another on the bipolar plate (112) with respect to a rotation of 180° about an axis of symmetry (118) of the bipolar plate (112) parallel to the stacking direction (110), and wherein in the stack (108), the first voltage tapping points (106a) of the first type of a plurality of bipolar plates (112) lie one above the other in a first row (120a) along the stacking direction, and the first voltage tapping points (106a') of the second type of a plurality of bipolar plates (112) lie one above the other in a second row (120b) along the stacking direction (110), wherein the first row (120a) and the second row (120b) of voltage tapping points are arranged adjacent to one another.

2. Electrochemical device according to claim 1, characterized in that the voltage tapping points (106a) of the first type and the voltage tapping points (106a') of the second type are arranged on mutually opposite end faces (144a, 144b) of the bipolar plate (112).

3. Electrochemical device according to one of claims 1 or 2, characterized in that the voltage tapping points (106) are each formed as a projection of the bipolar plate (112).

4. Electrochemical device according to one of claims 1 to 3, characterized in that each bipolar plate (112) comprises at least one first voltage tapping point (106a) of the first type and at least one second voltage tapping point (106b) of the first type, wherein in the stack (108), the first voltage tapping points (106a) of the first type of a plurality of bipolar plates (112) are arranged one above the other along the stacking direction (110) in the first row (120a), the first voltage tapping points (106a') of the second type of a plurality of bipolar plates (112) are arranged one above the other along the stacking direction (110) in the second row (120b), and the second voltage tapping points (106b) of the first type of a plurality of bipolar plates (112) are arranged one above the other along the stacking direction (110) in a third row (120c).wherein the first row (120a) and the second row (120b) are arranged adjacent to each other and / or the second row (120b) and the third row (120c) are arranged adjacent to each other., 5. Electrochemical device according to one of claims 1 to 4, characterized in that each bipolar plate (112) comprises at least one first voltage tapping point (106a) of the first type and one second voltage tapping point (106b) of the first type and at least one first voltage tapping point (106a') of the second type and one second voltage tapping point (106b') of the second type, wherein in the stack (108), the first voltage tapping points (106a) of the first type of a plurality of bipolar plates (112) lie one above the other along the stacking direction (110) in the first row (120a), the first voltage tapping points (106a') of the second type of a plurality of bipolar plates (112) lie one above the other along the stacking direction (110) in the second row (120b), the second voltage tapping points (106b) of the first type of a plurality of bipolar plates (112) lie one above the other along the stacking direction (110) in a third row (120c), and the second voltage tapping points (106b') of the second type of a plurality of bipolar plates (112) lie one above the other in a fourth row (120d), wherein the first row (120a) and the second row (120b) and / or the second row (120b) and the third row (120c) and / or the third row (120c) and the fourth row (120d) are arranged adjacent to each other.

6. Electrochemical device according to one of claims 1 to 5, characterized in that each bipolar plate (112) comprises at least n voltage tapping points (106) of the first type and at least m voltage tapping points (106) of the second type, wherein in the stack (108) the i-th voltage tapping points (106) of the first type of a plurality of bipolar plates (112) lie one above the other along the stacking direction (110) in an i-th row of the first type, with i = 1 to n, and the j-th voltage tapping points (106) of the second type of a plurality of bipolar plates (112) lie one above the other along the stacking direction (110) in a j-th row of the second type, with j = 1 to m.

7. Electrochemical device according to claim 6, characterized in that no row in which voltage tapping points (106) of the first type are located one above the other is arranged adjacent to a row in which voltage tapping points (106) of the first type are located one above the other.

8. Plug unit for contacting voltage tapping points (106) of an electrochemical device (102) according to one of claims 1 to 7, which comprises a plurality of electrochemical units which follow one another along a stacking direction (110), comprising a housing (114) which has a plurality of receptacles for each receiving a voltage tapping point (106) of the electrochemical device (102), wherein at least one of the receptacles is designed as a contact receptacle (138) in which, in the assembled state of the plug unit (104), an electrically conductive connection is established with the voltage tapping point (106) respectively received in the contact receptacle (138) by means of an electrically conductive contact element (142).

9. Plug unit according to claim 8, characterized in that at least one of the receptacles is designed as a dummy receptacle (150) in which, in the mounted state (104) of the plug unit (104), no electrically conductive connection is established with the voltage tapping point (106) respectively accommodated in the dummy receptacle (150).

10. Plug unit according to one of claims 8 or 9, characterized in that the receptacles of the plug unit (104) are arranged in a plurality of rows (136) which extend along a longitudinal direction (140) of the plug unit (104), and are arranged in a plurality of rows (152) which extend transversely to the longitudinal direction (140) of the plug unit (104).

11. Plug unit according to claim 10, characterized in that only one contact receptacle (138) is arranged in each row (152) of the plug unit (104).

12. Plug unit according to one of claims 8 to 11, characterized in that the plug unit (104) has dummy receptacles (150) for voltage tapping points (106) of the electrochemical device (102), in which, in the assembled state of the plug unit (104), no electrically conductive connection is established with the voltage tapping point (106) respectively received in the dummy receptacle (150), wherein the extent of at least one dummy receptacle (150) along the longitudinal direction (140) of the plug unit (104) is smaller than the extent of a contact receptacle (138) of the plug unit (104) along the longitudinal direction (140) of the plug unit (104).

13. Plug unit according to one of claims 8 to 12, characterized in that the receptacles of at least two rows (136) of receptacles of the plug unit (104) overlap one another - seen in the longitudinal direction (140) of the plug unit (104).

14. Combination of an electrochemical device (102) according to one of claims 1 to 7 and at least one plug unit (104) according to one of claims 8 to 13.

15. Combination according to claim 14, characterized in that at most one voltage tapping point (106) of each bipolar plate (112) of the electrochemical device (102) is accommodated in a contact receptacle (138) of a plug unit (104).

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