Electrical contact assembly for electrochemical cell

Abstract

The invention relates to an electrical contact arrangement for electrochemical cells (20), comprising a housing (1) having a plurality of groove-shaped recesses (7) for receiving respective contact pads (22) of the electrochemical cells (20), the housing (1) having a closed side (2). Each recess (7) is connected to the closed side (2) via a first opening (10) and a second opening (11). A contact element (15) having a first pin (16), a second pin (17) and a contact section (18) is arranged in each recess (7), the pins (16; 17) is arranged in the hole (10; 11) and the contact section (18) protrudes into the recess (7), so that the contact piece (22) can be clamped between the contact section (18) and the wall of the recess (7) in an electrical contact manner.

Description

Technical Field

[0001] The invention relates to an electrical contact assembly for an electrochemical cell, which is used for contacting a plurality of electrochemical cells and is preferably intended to be connected to a battery monitoring unit. Background Art

[0002] For example, an electrochemical cell is a fuel cell and is used to generate electrical energy from chemical energy. Another known electrochemical cell is the so-called electrolyzer, which can be used to generate chemical energy, particularly hydrogen, from water and electricity. Here, an electrochemical cell typically comprises multiple electrochemical cells connected in series to maximize the power per unit volume. The individual electrochemical cells are bounded by bipolar plates, which allow voltage tapping across the individual cells and also form the necessary channels for the supply and removal of chemicals and cooling media. Since all electrochemical cells in a cell are connected in series during operation, proper functioning of all cells is crucial. In fuel cells, this can be particularly evident from the voltage generated, which is approximately 0.8-1.0 volts per cell and should remain approximately constant during operation of the electrochemical cell. Significant deviations in individual electrochemical cells indicate a malfunction. This malfunction must be corrected promptly, otherwise the entire electrochemical cell will fail.

[0003] Cell voltage monitoring (CVM) is used to monitor the voltage generated by a single electrochemical cell. Such a battery monitoring unit is already known from patent application DE 10 2020 204 292 A1. Such a monitoring unit is usually in contact with each single bipolar plate, thereby allowing the voltage of each single cell to be measured. If the CVM detects a voltage deviation of the battery, a fault is indicated and corresponding measures can be initiated. Usually, the electrochemical cell must be shut down as soon as possible when a fault occurs, otherwise irreversible damage may occur. Since the single electrochemical cell is relatively flat (usually only 1 to 2 mm) and is stacked in large stacks of 100 to 500 cells, contacting each single electrochemical cell or bipolar plate is relatively difficult or complicated, which is also an important cost factor in the production of electrochemical cells. Summary of the Invention

[0004] The electrical contact assembly according to the invention for an electrochemical cell has the advantage of enabling simple and cost-effective contacting of each individual bipolar plate. To this end, the electrical contact assembly comprises a housing having a plurality of groove-shaped recesses for receiving corresponding contact strips, wherein the contact strips are connected to the bipolar plates or are integrally formed with the bipolar plates. The housing has a closed side, wherein each recess is connected to the closed side via a first hole and a second hole. A contact element is arranged in the recess, comprising a first pin, a second pin, and a contact section, wherein the pins are each arranged in a corresponding one of the holes, and the contact section extends into the recess. The contact section is designed so that the contact strip can be clamped between the contact section and the wall of the recess to enable electrical contact.

[0005] The electrochemical cell unit has a plurality of electrochemical cells stacked on top of each other. The electrochemical cell is composed of bipolar plates, which delimit two adjacent electrochemical cells and implement electrical connections therein. The electrical connection is led to the outside in the form of a contact sheet, wherein the contact sheet is constructed integrally with the bipolar plate or is formed by a separate component connected to the bipolar plate. The contact sheet can be easily inserted into the groove-shaped recess of the housing of the electrical contact assembly. The contact section of the contact element is located in each recess, through which the bipolar plate is contacted when inserted into the housing. This electrical contact is guided to the closed side of the housing by the contact element, where it can be connected to the corresponding evaluation unit. This simply constructed unit for electrical contact can be manufactured advantageously and is suitable for contacting a large number of electrochemical cells and connecting to a battery monitoring unit.

[0006] In a first advantageous embodiment, the groove-shaped recesses are oriented parallel to one another, thus forming a comb-like support structure. In particular, the housing is essentially cuboid in shape and has, in addition to a closed side, an opposite open side and two side faces, wherein the side faces connect the closed side and the open side. This creates a recess that is open on three sides, making it easier to insert the contact piece. This comb-like support structure can be cut, for example, by sawing a block ( The blocks and thus the housing are made of a non-conductive material, such as plastic or ceramic.

[0007] Advantageously, the first pin of the contact element is arranged in the hole in the assembled position and protrudes from the closed side of the housing, while the second pin does not protrude beyond the closed side. Since the first pin is in electrical contact with the contact section of the contact element, an electrical connection is established between the pin protruding from the housing and the contact sheet or bipolar plate. The second pin is also received in the hole, preventing the contact element from slipping or rotating within the recess, which could disrupt contact.

[0008] In another advantageous embodiment, the thickness of the contact section of the contact element in the stacking direction of the electrical contact assembly or housing is smaller than the thickness of the recess, thereby creating a space for receiving and clamping the contact piece between the contact section of the contact element and the wall of the recess.

[0009] In another advantageous embodiment, the first holes, which connect the respective recesses to the closed side of the housing, are arranged in a row, wherein the row extends in the stacking direction of the housing, which also corresponds to the stacking direction of the electrochemical cells when the electrical contact assembly is mounted on the electrochemical cells. The second holes are also advantageously arranged in a row and are also stacked in the stacking direction.

[0010] In another advantageous embodiment, the contact elements are arranged in the recesses such that the first contact pins protrude alternately from the first and second holes, and thus in adjacent recesses the first contact pins protrude alternately from the first and second holes. This results in a relatively large distance between the contact pins, which can be more easily connected to the electrical evaluation unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The drawings show different embodiments of electrical contact assemblies. They show:

[0012] Figure 1 A perspective view of an electrical contact assembly or a housing of an electrical contact assembly, wherein only a small part of the electrical contact assembly is shown here for the sake of clarity,

[0013] Figure 2a shows the electrical contact elements,

[0014] Figure 2b The same electrical contact element in different orientations,

[0015] Figure 3a The installation position of the contact element in the housing,

[0016] Figure 3b The installation position of the contact element in the adjacent recess of the housing,

[0017] Figure 4 The cross section of the housing, the contact portion of the contact sheet, and

[0018] Figure 5 Electrical contact assembly with mounted contact elements in a perspective view. DETAILED DESCRIPTION

[0019] Figure 1The electrical contact assembly according to the invention is shown in a three-dimensional diagram, wherein only the housing is shown here. The housing 1 is of rectangular shape and has a closed side 2, which is opposite to the open side 3. The two sides 2, 3 are connected to each other by side surfaces 4 and 5. The housing 1 has a plurality of groove-shaped recesses 7, which are open toward the open side 3 and toward the side surfaces 4 and 5 and are parallel to each other. This results in a comb-like structure of the housing 1 with recesses 7, which are open toward the three sides of the rectangular housing 1. The recesses 7 are connected to the closed side 2 of the housing 1 by a first hole 10 and a second hole 11 parallel to the first hole, respectively. The holes 10, 11 form a first opening 110 or a second opening 111 on the closed side 2. All first holes 10 and second holes 11 are arranged in a row superimposed in the stacking direction R, so that all first openings 110 and second openings 111 also form a row accordingly. For the sake of clarity, Figure 1 The housing 1 shown in FIG shows only two recesses 7. In practice, however, there are usually many more recesses 7, possibly several hundred, corresponding to the number of contacts of the electrochemical cell.

[0020] Figure 2a 7 shows a contact element 15 arranged in recess 7 for assembly. Contact element 15 has a first pin 16 and a second pin 17 that are parallel to each other, wherein first pin 16 is longer than second pin 17. The two pins 16 and 17 are connected to each other via a connecting section 19. In addition, a contact section 18 is also connected to connecting section 19, which is opposite second pin 17, so that contact element 15 has a substantially H-shaped shape. Figure 2b The same contact element 15 is shown, however, here rotated 180 degrees, corresponding to the installed position in the adjacent recess 7 of the housing 1. Figure 2a 、 2b In the embodiment shown, the pins 15 and 16 have a square cross section; however, contact elements 15 with differently shaped cross sections may be used, for example circular, oval or rectangular.

[0021] Figure 3a The installation position of the contact element 15 in the housing 1 or the recess 7 is shown in cross section. A first pin 16 is arranged in the first hole 10, and a second pin 17 is arranged in the second hole 11. The first pin 16, due to its length, protrudes beyond the closed side 2 of the housing 1, where it makes electrical contact and is connected to the voltage monitoring unit. The contact section 18 extends into the recess 7, but does not extend beyond the open side 3 of the housing 1. Figure 3aThe right side of the figure shows a contact lug 22 that is electrically connected to or forms part of a bipolar plate. The bipolar plate is part of an electrochemical cell, such as a fuel cell or electrolyzer. The contact lug extends into the recess 7 and there contacts the contact section 18 of the contact element 15, thereby electrically connecting the contact element. This creates an electrical connection between the first pin 16 of the contact element 15, which protrudes beyond the closed side 2 of the housing 1, and the bipolar plate. Figure 3b With Figure 3a The same illustration shows the installed position in the adjacent recess 7 of the housing 1. Here, the contact element is rotated 180 degrees in the plane, so that the first pin 16 now projects through the second hole 11 and the second pin 17 projects through the first hole 10 of the recess 7.

[0022] Figure 4 A longitudinal section through the housing 1 shows the contacting of an electrochemical cell 20 via an electrical contact assembly. The electrochemical cell 20 comprises a plurality of electrochemical cells 21 stacked one on top of the other, wherein each electrochemical cell 21 is formed by a bipolar plate. Each bipolar plate delimits two adjacent electrochemical cells 21 and also forms the corresponding electrical contact for the associated electrochemical cell. The electrical contacts of the bipolar plates can be directed outward in the form of contact tabs 22, which extend beyond the edges of the electrochemical cell 20 and into each recess 7 in the housing 1. The contact tabs 22 can be part of the bipolar plate or connected to the bipolar plate as a separate component. Because the groove-shaped recess 7 has a thickness a in the stacking direction that is greater than the thickness b of the contact section 18, the contact tabs 22 can be sandwiched between the contact section 18 and the wall of the recess 7, thereby electrically connecting to the contact element 15.

[0023] As in Figure 2a and Figure 2b As shown in FIG, in order to assemble the electrical contact assembly, the housing 1 is provided with contact elements 15 oriented alternately. The first pins 16 alternately extend outward through the first holes 10 and the second holes 11 of the recesses 7, so that the first pins are positioned as shown in FIG. Figure 5 In the manner shown, the contact elements 15 extend beyond the closed side 2 of the housing 1 . The alternating orientation of the contact elements 15 increases the distance between adjacent first pins 16, which facilitates contact with the electrical evaluation unit. It should be noted that an electrochemical cell typically comprises several hundred electrochemical cells, each having a thickness of only approximately 1 mm. The distance between the first pins 16 is correspondingly small. The electrical contact assembly is then mounted on the electrochemical cell, with the corresponding contact lug 22 inserted into the recess 7 , where it is clamped between the contact section 18 of the corresponding contact element 15 and the wall of the recess 7 , thereby achieving electrical contact.

[0024] The contact element 15 is preferably composed of a metal wire having good electrical conductivity. The wire may have a circular, square or rectangular cross section, such as Figure 2a and Figure 2b . However, other cross-sections, such as an oval, can also be used to improve the grip of the contact piece 22. In any case, the dimensions of the pins 16, 17 must be coordinated with the holes 10, 11 so that the pins 16, 17 can be inserted into the holes 10, 11. Accordingly, the holes 10, 11 can also be manufactured, for example, with a square, rectangular, or oval cross-section.

Claims

1. An electrical contact assembly for an electrochemical cell (20), comprising a housing (1) having a plurality of groove-shaped recesses (7) for receiving corresponding contact strips (22), wherein: The housing (1) has a closed side (2), It is characterized in that Each recess (7) is connected to the closed side (2) via a first hole (10) and a second hole (11), and a contact element (15) is arranged in the recess (7), the contact element having a first pin (16), a second pin (17) and a contact section (18), wherein the pin (16; 17) is arranged in a corresponding one of the holes (10; 11) and the contact section (18) extends into the recess (7), so that a contact piece (22) can be clamped between the contact section (18) and the wall of the recess (7) for establishing an electrical connection between the contact element (15) and the contact piece (22).

2. The electrical contact assembly according to claim 1, wherein: The groove-shaped recesses (7) are oriented parallel to one another, thereby forming a comb-shaped support structure.

3. The electrical contact assembly according to claim 2, wherein: The housing (1) is constructed in a substantially cuboid shape and has an open side (3) opposite the closed side (2), a first side surface (4) and a second side surface (5), wherein the side surfaces (4; 5) connect the closed side (2) and the open side (3).

4. The electrical contact assembly according to claim 3, characterized in that The recess (7) is open toward the open side (3) and the side surfaces (4; 5).

5. The electrical contact assembly according to any one of claims 1 to 4, characterized in that In the assembled position, the first pin (16) of the contact element (15) projects from the closed side (2) of the housing (1), while the second pin (17) does not project beyond the closed side (2).

6. The electrical contact assembly according to claim 5, characterized in that The first pin (16) is electrically connected to the contact section (18).

7. The electrical contact assembly according to any one of claims 1 to 6, characterized in that: The thickness (b) of the contact section (18) of the contact element (15) in the stacking direction (R) of the groove-shaped recess (7) is smaller than the thickness (a) of the recess (7).

8. The electrical contact assembly according to any one of claims 1 to 7, characterized in that: The first hole (10) and the second hole (11) respectively form openings (110; 111) on the closed side (2) of the housing (1), and the openings (110; 111) of the first hole (10) and the second hole (11) are respectively arranged to overlap in a stacking direction (R).

9. The electrical contact assembly according to claim 8, characterized in that The first contact pins (16) of the contact element (15) protrude alternately from the first holes (10) and the second holes (11) in adjacent recesses (7).

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