DE102016225028A1 - Connection system for connecting separator plates of a fuel cell stack - Google Patents

Abstract

The invention relates to a connection system for connecting separator plates of a fuel cell stack to a cell monitoring module, comprising a connection element configured to contact a plurality of separator plates of the fuel cell stack, comprising at least one separator plate contact element, a cell monitor board adapted to receive the cell monitoring module, and a one-piece flexible connection plate and rigid printed circuit boards, comprising a line section formed by at least one flexible printed circuit board, a rigid or flexible contact printed circuit board at one end of the line section, wherein the rigid contact printed circuit board is arranged in or on the connecting element and the contact elements are electrically conductively connected to the rigid contact Circuit board are connected, and a rigid or flexible connection board at the other end of the line section, wherein the connection board for connection to the Zellüberwachun gsplatine is formed or is an integral part of the cell monitoring board.

Description

The technology disclosed herein relates to a connection system for connecting separator plates of a fuel cell stack to a cell monitoring module. Further, the technology disclosed herein relates to a fuel cell system, preferably in a vehicle, comprising the connection system.

Cell monitoring systems for fuel cell systems include a connection system having a connector for contacting the separator plates (monopolar plates or bipolar plates) of a fuel cell stack. Furthermore, the connection system comprises corresponding electrical conductors for connecting the connection element to a cell monitoring module of the cell monitoring system. The processing or evaluation of the signals picked up on the separator plates takes place in the cell monitoring module.

For example, cell monitoring systems (or CVM system) are off WO 2007 102031 A1 and WO 2005 069026 A1 known. A connecting element for contacting the separator plates is for example made DE 10 2007 003506 B4 known.

It is an object of the technology disclosed herein to reduce or eliminate the disadvantages of prior art solutions. In particular, it is an object of the technology disclosed here to specify a connection system for connecting separator plates of a fuel cell stack to a cell monitoring module, which enables a reliable and permanent electrical connection between the cell monitoring module and the separator plates with simple production and simple assembly. Other objects arise from the beneficial effects of the technology disclosed herein. The object (s) is / are solved by the subject matter of claim 1. The dependent claims are preferred embodiments.

The technology disclosed herein relates, inter alia, to a fuel cell system having a plurality of stacked fuel cells. The fuel cell system is intended, for example, for mobile applications such as motor vehicles, in particular for providing the energy for at least one drive machine for locomotion of the motor vehicle. In its simplest form, a fuel cell is an electrochemical energy converter that converts fuel and oxidant into reaction products, producing electricity and heat. The fuel cell includes an anode and a cathode separated by an ion-selective or ion-permeable separator. The anode is supplied with fuel. Preferred fuels are: hydrogen, low molecular weight alcohol, biofuels, or liquefied natural gas. The cathode is supplied with oxidant. Preferred oxidizing agents are, for example, air, oxygen and peroxides. The ion-selective separator can be designed, for example, as a proton exchange membrane (PEM). Preferably, a cation-selective polymer electrolyte membrane is used. Materials for such a membrane are, for example: Nafion®, Flemion® and Aciplex®.

A fuel cell system comprises, in addition to the fuel cells, peripheral system components (BOP components) which can be used during operation. As a rule, several fuel cells are combined to form a fuel cell stack or stack.

The fuel cells of the fuel cell system include i.d.R. two separator plates. The ion-selective separator of a fuel cell is i.d.R. each arranged between two separator plates. The one separator plate forms the anode together with the ion-selective separator. The further separator plate arranged on the opposite side of the ion-selective separator, however, forms the cathode together with the ion-selective separator. Gas channels for fuel or for oxidants are preferably provided in the separator plates.

The separator plates can be designed as monopolar plates and / or as bipolar plates. In other words, a separator plate expediently has two sides, one side forming an anode together with an ion-selective separator and the second side forming a cathode together with another ion-selective separator of an adjacent fuel cell. Between the ion-selective separators and the separator plates are i.d.R. still so-called gas diffusion layers or gas diffusion layers (GDL) provided.

Further, the technology disclosed herein relates to a cell monitoring system. The cell monitoring system (CVM system), in particular the cell monitoring module of the cell monitoring system, can be designed to monitor the condition of at least one cell. It usually monitors the condition of a large number of fuel cells. Monitoring in this context means that the system can directly or indirectly determine the state of the monitored cells. Thus, an occurring degradation or a cell failure can be detected early and appropriate countermeasures can be initiated. It can thereby possibly the life span in a certain Be increased and / or by appropriate countermeasures, the performance of the cell population can be increased. Advantageously, at least one measured variable can be detected directly or indirectly. The measured variable may in particular be the electrical voltage of the monitored cell. Advantageously, the single cell voltages of several or all cells and the total voltage are determined. Preferably, the current flowing through the fuel cell stack is further determined. From the measured voltages, the CVM system can determine, for example, one of the following values: minimum, maximum and mean value of the single-cell voltage. Advantageously, voltage deviations between the individual cells or at an average of the individual cell voltages can thus be detected. Preferably, further single-cell analysis methods are carried out, such as, for example, an impedance calculation (eg: electrochemical impedance spectroscopy).

The object of the technology disclosed here is achieved by a connection system for connecting separator plates of a fuel cell stack to a cell monitoring module. For this purpose, the connection system comprises a connecting element, a cell monitoring board and a one-piece connection board, also referred to as Starflex board.

The connecting element can also be referred to as a connecting plug. The connecting element is designed in particular for the simultaneous contacting of a plurality of separator plates. For this purpose, the connecting element comprises at least one contact element for a separator plate, preferably a plurality of contact elements for a plurality of separator plates. The connecting element is in particular attached to a plurality of separator plates, wherein the contact elements contact the separator plates by being plugged on. In particular, the connecting element is designed to contact at least one separator plate. The connecting elements are in particular designed such that a plurality of the connecting elements can be plugged directly next to one another onto the fuel cell stack so that any desired separator plate of the fuel cell stack can be contacted. Not all separator plates must be contacted.

The cell monitoring board is designed to receive the cell monitoring module. In the cell monitoring module, the processing or evaluation of the signals picked up via the connecting elements or at least the forwarding of the signals to a higher-order arithmetic unit takes place. The cell monitoring board and thus also the cell monitoring module can be electrically conductively connected to a plurality of the connecting elements.

The connection board (also: rigid-flex board) is a combination of flexible and rigid printed circuit boards. It is a one-piece component where the traces extend from the rigid printed circuit boards to the flexible printed circuit boards and from the flexible printed circuit boards to the rigid printed circuit boards. The flexible circuit boards or the interconnects contained therein are thus not infected or soldered to the rigid circuit boards. The rigid circuit boards are by a plastic carrier layer, for example, 1-2 mm, rigid and are not designed for a bending load. The flexible printed circuit boards are very flexible due to a very thin, film-like support, in particular thinner than 2 mm, and can generally be installed in loops with over 180 ° bends. The flexible printed circuit boards can thus also be referred to as "conductor foils".

According to the invention, such a connection board is used with flexible and rigid circuit boards for connecting the contact elements of the connection element to the cell monitoring board. The connection board comprises a line section formed by at least one flexible circuit board.

Further, the interconnect board includes a rigid or flexible contact circuit board at one end of the conduit section. The contact circuit board is located in or on the connecting element. In particular, the connection element comprises a connection element housing, wherein the contact circuit board is arranged in or on the connection element housing. In the connecting element, the contact elements are electrically conductively connected to the contact printed circuit board.

At the other end of the line section, the connection board has a rigid or flexible connection board. Preferably, the interconnects of the interconnect board extend continuously, i. without solder or plug connections, from the contact printed circuit board via the line section with the at least one flexible printed circuit board to the connecting printed circuit board. There are two preferred variants for the design of the connection printed circuit board:

According to the first variant, the connection printed circuit board is designed for connection to the cell monitoring board. For this purpose, the connection circuit board can be plugged, for example, to the cell monitoring board.

According to the second variant, the terminal board is an integral part of Cell monitoring board. The connector board and the cell monitor board are thus the same board. The cell monitoring board is part of the one-piece connection board.

The line section may include branching points, wherein from the branching point individual flexible printed circuit boards lead to two or more connecting elements, and wherein from the branching point in a common flexible printed circuit board, the printed conductors of at least two connecting elements lead together to the connecting printed circuit board.

By using the connection board, the connection system is very easy and inexpensive to produce. Further, the connector board is a one-piece component that can be easily mounted.

For example, when using the connection system in a motor vehicle, the line section of the connection board can be set in motion relative to the surrounding components. As a result, the line section touching surrounding components, whereby a mechanical or thermal damage of the line section is possible. To avoid this, it is preferably provided that the line section has at least one first attachment point. Outside the line section, a second attachment point is provided. The first attachment point is designed for attachment to the second attachment point. The line section is already firmly connected at its ends to the contact printed circuit board and the connection printed circuit board. By the first attachment point, the line section can be attached not only at its ends, but also between its ends.

In the context of the technology disclosed here, different examples for the design of the two fastening points are shown. In general consideration, the two attachment points for a non-positive and / or positive and / or material connection of the line section are formed with a surrounding component. For the frictional or positive connection in particular screws and / or rivets and / or snap-in connections and / or tongue and groove joints are used. In the cohesive connection in particular a bonding of the two attachment points takes place.

In the context of the present technology, primarily only a first attachment point and an associated second attachment point are described. However, it is also provided that along the line section a plurality of first attachment points are formed. Accordingly, a plurality of second attachment points for securing the associated first attachment point are then provided outside the line section.

In a preferred embodiment, the connection system comprises a housing. The housing is designed to receive the cell monitoring board and / or to receive the fuel cell stack. The housing does not necessarily enclose the cell monitoring board or the fuel cell stack. As "housing" here are also considered components that carry, for example, the cell monitoring board or only partially cover the fuel cell stack. Of course, the "housing", depending on the perspective, also be part of the fuel cell stack or the fuel cell system. Preferably, the second attachment point is formed on the housing, so that the line portion of the connection board can be fixed to the housing.

Furthermore, it is preferably provided that the connecting element comprises the connecting element housing already described. The connector housing accommodates the contact circuit board. For this purpose, the contact printed circuit board is arranged either in or on the connector housing. Preferably, the second attachment location is on the connector housing so that the conduit portion of the connector board can be secured to the connector housing.

It is preferably provided that the first attachment point is formed as a recess in the line section. This recess is in particular a hole, a slot or a slot. The second attachment point preferably has an extension. The extension is designed for insertion into the recess. At least one latching lug is preferably formed on the extension, at or below which the first attachment point engages when attaching the recess to the extension.

As an alternative to the extension, provision is also preferably made for an element, such as a screw or a rivet, to be inserted into the recess, in which case a corresponding hole for receiving the element is provided at the second fastening point.

In a particularly preferred embodiment, it is provided that the line section has two flexible printed circuit boards and a rigid intermediate printed circuit board. The rigid intermediate circuit board is located between the two flexible circuit boards. The intermediate circuit board is also part of the one-piece connection board. The tracks thus extend continuously from one flexible circuit board over the rigid intermediate circuit board to the next flexible circuit board. The line section may also comprise a plurality of rigid intermediate circuit boards, in which case a flexible circuit board is then arranged in each case between two rigid intermediate circuit boards. The already described branching within the line section may also be formed by such a rigid intermediate circuit board, in particular referred to as a rigid branch circuit board.

In particular, it is provided that only printed conductors and no electronic components such as resistors, capacitors, transistors, etc. are arranged on the intermediate printed circuit board, just as on the flexible printed circuit boards.

It is preferably provided that the rigid intermediate circuit board has the first attachment point or represents the first attachment point. This rigid or solid component is very suitable for the attachment of the line section.

The first attachment point in the rigid intermediate printed circuit board is designed according to an advantageous variant, as already described above, as a recess.

In order to use the entire rigid intermediate circuit board as a "first attachment point", it is preferably provided to form at least one groove at the second attachment point. In this groove, the rigid intermediate circuit board can be inserted positively. Particularly preferred are located at the second attachment point two opposing grooves, wherein the intermediate circuit board between the two grooves is positively inserted.

Furthermore, it is preferably provided that the second attachment point has at least one latching lug, wherein the rigid intermediate circuit board can be latched under this latching lug.

Furthermore, it is preferably provided that the connection system comprises at least one fastening element. The fastening element is for applying, for example, plugging or pushing, formed on both attachment points, wherein the fastening element surrounds the attachment points and / or engages in the attachment points, so as to connect the two attachment points form-fitting and / or non-positively. In particular, the fastener is designed as a clamp which is placed on the first attachment point, the line section thereby engages laterally with two arms, wherein the two arms engage in corresponding recesses of the second attachment point or embrace the second attachment point.

The technology disclosed herein further includes a fuel cell system. The fuel cell system is located in particular in a vehicle. The fuel cell system includes at least one connection system just described, a fuel cell stack having separator plates contacted by the connector, and a cell monitoring module on the cell monitoring board. The advantageous embodiments described in the context of the disclosed connection system and subclaims accordingly find advantageous application to the disclosed fuel cell system.

• 1 eine schematische Ansicht des offenbarten Verbindungssystems in einem Brennstoffzellensystem,
• 2 eine schematische Ansicht einer Variante des offenbarten Verbindungssystems in einem Brennstoffzellensystem,
• 3-7 schematische Ansichten verschiedener Varianten von Befestigungsstellen des offenbarten Verbindungssystems, und
• 8, 9 schematische Ansichten verschiedener Varianten zur Positionierung der Verbindungstellen des offenbarten Verbindungssystems.

The technology disclosed herein will now be explained with reference to the schematic figures. Show it:

• 1 a schematic view of the disclosed connection system in a fuel cell system,
• 2 a schematic view of a variant of the disclosed connection system in a fuel cell system,
• 3 - 7 schematic views of different variants of attachment points of the disclosed connection system, and
• 8th . 9 schematic views of different variants for positioning the joints of the disclosed connection system.

The 1 to 9 show the disclosed connection system 1 in a fuel cell system 2 in different variants.

The fuel cell system 2 is used in particular in a vehicle. The fuel cell system 2 includes a fuel cell stack with multiple separator plates 3 , The separator plates 3 are in particular monopolar plates or bipolar plates of the fuel cell stack.

Furthermore, the fuel cell system includes 2 a cell monitoring module 4. By means of the connection system 1 is the cell monitoring module 4 electrically conductive with the Separatorplatten 3 connected. The unit of connection system 1 and cell monitoring module 4 can also be referred to as a cell monitoring system.

The connection system 1 comprises a connecting element 5 , The connecting element 5 has a connector housing 501 and a plurality of contact elements 502 in or on the connector housing 501 on. In the assembled state, the connecting element is inserted 5 on several separator 3 , In each case, at least one contact element contacts 502 a separator plate 3 , In particular, in the fuel cell system 2 several fasteners 5 provided to all separator plates 3 to contact.

Furthermore, the connection system includes 1 a cell monitor board 6. The cell monitor board 6 is designed to receive the cell monitoring module 4.

To connect the cell monitoring module 4 with the separator plates 3 includes the connection system 1 a one-piece connector board 7 , The connection board 7 in turn, in one-piece embodiment comprises a rigid contact printed circuit board 703 , a rigid connection board 704 and a flexible conduit section 701 for connecting the contact circuit board 703 with the connection board 704 ,

The pipe section 701 the connection board 7 points, as for example 1 shows, at least one flexible circuit board 702 on. The flexible circuit board 702 In particular, it is so flexible that, as shown in FIGS 1 and 2 perpendicular to the plane or as shown in 8th and 9 bent in the drawing plane or can be installed in loops or curves.

Furthermore, the interconnect board includes 7 a variety of tracks 707 extending continuously from the contact circuit board 703 via the line section 701 to the terminal board 704 extend. In the variants shown is the connection board 704 integral part of the cell monitoring board 6 , Thus, the cell monitoring board 6 Part of the one-piece connector board 7 ,

In 1 leads from each connecting element 5 an unbranched line section 701 up to that in the cell monitoring board 6 integrated connection circuit board 704 ,

In the variant after 2 points the line section 701 a branch formed by a rigid branch circuit board 705 on. The branch circuit board 705 is part of the one-piece connector board 7 , From the branch circuit board 705 lead single flexible circuit boards 702 to the connecting elements 5 , From the branch circuit board 705 leads a common flexible circuit board 702 with the coming of two connecting elements 5 interconnects 707 to the rigid connection board 704 , integrated into the cell monitoring board 6 ,

2 merely shows one of several possible embodiments for the branch within the line section 701 , For example, it is also provided that the conductor tracks 707 of more than two connectors 5 on a branch circuit board 705 on a common, flexible circuit board 702 be summarized.

At one or more positions of the pipe section 701 out 1 or 2 can be a first attachment point 81 be educated. Outside the line section 701 is in each case a complementary to the first attachment point 81 second attachment point 82 , The two attachment points 81, 82 are connected to each other, so that the line section 701 is fastened.

The 3 to 7 show different embodiments of the attachment points 81 . 82 , The design of the attachment points 81 . 82 is not on the in the 3 to 7 limited variants shown. Rather, it is generally considered that the two attachment points 81 . 82 for a non-positive and / or positive and / or material connection of the line section 701 are formed with a surrounding component.

According to 3 has the flexible circuit board 702 a lateral bulge on. This lateral bulge serves as a first attachment point 81 , In particular, a recess is provided in the lateral bulge over which the first attachment point 81 with the second attachment point 82 can be connected.

4a shows a variant in which the first attachment point 81 formed as a recess, located in the middle of the flexible circuit board 702 located. It is provided in particular that at least one conductor track 707 this recess circulates arcuately.

4b shows a variant with two parallel line sections 701 which are spaced apart from each other and connected to each other in at least one place. This connected location may be through a rigid printed circuit board or flexible printed circuit board of the one-piece interconnect board 7 be formed. The first attachment point 81 is located, preferably as a recess, in the connected position between the two parallel line sections 701 ,

In a particularly preferred variant according to 5 points the line section 701 a rigid intermediate circuit board 706 on. In particular, also the rigid connection circuit board 705 the rigid intermediate circuit board 706 represent. The rigid one Between board 706 is part of the one-piece connector board 7 and is located between two flexible circuit boards 702 ,

The first attachment point 81 is located in particular in this intermediate circuit board 706 , For this purpose, the first attachment point 81 again provide a recess.

Furthermore, for example, as shown in FIG 6 , provided, the entire intermediate circuit board 706 as the first attachment point 81 to use. For this purpose, for example, the second attachment point 82 two opposite grooves 83 on. In these grooves 83 can the intermediate circuit board 706 be inserted positively. Alternative to the grooves 83 can also be provided any kind of latching connection for engaging the intermediate circuit board 706.

7 shows a further variant in which the two attachment points 81 . 82 on top of each other and by means of a fastener 84 connected to each other. The fastener 84 lies on the first attachment point 81 on and includes two lateral arms in the corresponding recesses of the second attachment point 82 intervention. 7 shows this fastener 84 purely by way of example, with very different embodiments of the fastening element 84 for a positive and / or non-positive connection of the two fastening points 81 . 82 possible are.

8th and 9 show different variants for the positioning of the two attachment points 81 . 82 within the fuel cell system 2 ,

8th shows one of the separator plates 3 with attached connector 5. In the connector 5 is the rigid contact circuit board 703 , In this view, only one of the contact elements 502 , connected to the contact circuit board 703 to see. The contact element 502 stuck on the separator plate 3 ,

Above the stack of separator plates 3 there is a housing 9 , The housing 9 extends over several of the separator plates 3 , The housing 9 covers one side of the separator plates 3 at least partially off. Furthermore, the housing serves 9 for receiving the cell monitoring board 6 ,

The pipe section 701 includes two flexible circuit boards 702 and a rigid intermediate circuit board 706 , The rigid intermediate circuit board 706 lies on the housing 9 at. At the intermediate circuit board 706 and the housing 9 are the attachment points 81 . 82 educated. For the design of this attachment is any variant for a positive and / or non-positive and / or material connection, for example, after 3 to 7 , possible.

Further shows 8th in that, according to an advantageous embodiment, the line section 701 in the flexible circuit boards 702 at least one loop 10 has. The loops 10 lead to a flexibility of the line section 701, in particular perpendicular to the plane according to 8th and 9 ,

In the example shown 8th are two loops 10 , each with an angle α of about 90 °, provided. The two loops 10 are located on both sides of the rigid intermediate circuit board 706 and thus on both sides of the attachment points 81 . 82 ,

In the variant after 9 is the pipe section 701 by means of the rigid intermediate circuit board 706 on the outside of the connector housing 501 attached. Again, for the embodiment of the attachment any variant for a positive and / or non-positive and / or cohesive connection, for example according to the 3 to 7 , be used.

In 9 allows the position of the two attachment points 81 . 82 the fixation of the line section 701 with a 180 ° loop 10 in the flexible circuit board 702 ,

In general consideration, it is preferably provided that the line section 701 at least a loop 10 having an angle α between 45 ° and 220 °.

The foregoing description of the present invention is for illustrative purposes only, and not for the purpose of limiting the invention. Various changes and modifications are possible within the scope of the invention without departing from the scope of the invention and its equivalents.

LIST OF REFERENCE NUMBERS

1

connection system

2

The fuel cell system

3

separator

4

Cell monitoring module

5

connecting member

501

Connection element housing

502

contact elements

6

Cell monitoring board

7

connecting board

701

line section

702

flexible circuit board

703

rigid contact printed circuit board

704

rigid connection circuit board

705

rigid branch circuit board

706

rigid intermediate circuit board

707

conductor tracks

81

first attachment point

82

second attachment point

83

groove

84

fastener

9

casing

10

loop

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2007102031 A1 [0003]
• WO 2005069026 A1 [0003]
• DE 102007003506 B4 [0003]

Claims (11)

Connection system (1) for connecting separator plates (3) of a fuel cell stack to a cell monitoring module (4), comprising A connecting element (5) designed to contact a plurality of separator plates (3) of the fuel cell stack, with at least one contact element (502) for a separator plate (3), A cell monitoring board (6) adapted to receive the cell monitoring module (4), and • a one-piece connector board (7) with flexible and rigid printed circuit boards, comprising A line section (701) formed by at least one flexible printed circuit board (702), ■ a rigid or flexible contact printed circuit board (703) at one end of the line section (701), wherein the rigid contact printed circuit board (703) in or on the connecting element (5) is arranged and the contact elements (502) electrically conductive with the rigid contact Printed circuit board (703) are connected, and A rigid or flexible terminal board (704) at the other end of the line section (701), the terminal board (704) being for connection to the cell monitor board (6) or integral with the cell monitor board (6). Connection system after Claim 1 wherein the conduit section (701) includes at least one first attachment location (81) adapted for attachment to a second attachment location (82) external to the conduit section (701), around the conduit section (701), in addition to its attachment to the Contact PCB (703) and the terminal board (704) to attach. Connection system after Claim 2 comprising a housing (9) for receiving the cell monitoring board (6) and / or for receiving the fuel cell stack, wherein the second attachment point (82) on the housing (9) is formed. Connection system according to one of Claims 2 or 3 wherein the connector (5) comprises a connector housing (501) receiving the contact circuit board (703), the second mounting location (82) being formed on the connector housing (501). Connection system according to one of Claims 2 to 4 , wherein the first attachment point (81) has a recess, preferably a hole, a slot or a slot. Connection system after Claim 5 , wherein the second attachment point (82) has an extension for attaching the recess of the first attachment point (81). Connection system according to one of Claims 2 to 6 wherein the lead portion (701) comprises two flexible circuit boards (702) and a rigid intermediate circuit board (706) between the two flexible circuit boards (702), the first mounting location (81) being formed in the rigid intermediate circuit board (706) or the rigid intermediate circuit board (706) forms the first attachment point (81). Connection system after Claim 7 wherein the second attachment location (82) comprises at least one groove (83), preferably two opposing grooves, for insertion of the rigid intermediate circuit board (706). Connection system according to one of Claims 7 or 8th wherein the second attachment point (82) comprises at least one latching lug for latching the rigid intermediate circuit board (706). Connection system according to one of Claims 2 to 9 comprising a fastening element (84) for application to both fastening points (81, 82), wherein the fastening element (84) surrounds the fastening points (81, 82) and / or engages in the fastening points (81, 82) in order to fix the two fastening points (81 , 82) to connect positively and / or non-positively. Fuel cell system (2), preferably in a vehicle comprising At least one connection system (1) according to one of the preceding claims, A fuel cell stack with separator plates (3) contacted by the connecting element (5), and A cell monitoring module (4) on the cell monitoring board (6).

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