Fuel cell equipment

Abstract

The invention relates to a fuel cell device (1), comprising a fuel cell stack (12), the fuel cell stack being formed by a plurality of unit cells (11) stacked one on top of the other in a stacking direction, the unit cells each having one or more media channels (8) and a membrane electrode assembly (2), the membrane electrode assembly comprising a cathode, an anode and a membrane arranged between the cathode and the anode, and the fuel cell device having a media guide (22) extending substantially parallel to the stacking direction. The media guide (22) is connectable to the fuel cell stack (12) or is connected to the fuel cell stack (12) in order to guide a medium into or out of the media channels (8) of the unit cells (11) of the fuel cell stack (12) substantially transversely to the stacking direction.

Description

Technical Field

[0001] The present invention relates to a fuel cell device having a fuel cell stack, wherein the fuel cell stack is formed by a plurality of unit cells stacked on each other in a stacking direction. Each unit cell has one or more media channels and a membrane electrode assembly (MEA). The membrane electrode assembly comprises a cathode, an anode and a membrane arranged between the cathode and the anode. In addition, the fuel cell device also has a media guide extending substantially parallel to the stacking direction. Background Art

[0002] Known fuel cell devices have channels constructed in the fuel cell stack along the stacking direction. In order to ensure that the reaction media do not mix, complex sealing structures are required. In addition, when operating the fuel cell stack, it should also be ensured that the media does not pass out into the environment.

[0003] A fuel cell device is shown in DE 10 2007 023 544 A1. The collecting ducts for the operating medium and / or the cooling medium are surrounded by a peripheral seal. It must be ensured that each of the unit cells of the fuel cell stack has a corresponding seal on the collecting duct or that corresponding channels are provided for the media supplied to the active area. Such a sealing structure is expensive to manufacture.

[0004] JPS 61-185871 describes an air-cooled fuel cell stack in which an external medium guide is attached to the plate stack. The medium always exits on the same side of the fuel cell stack as that on which it enters; in other words, the medium is introduced and discharged at the same edge, which leads to efficiency disadvantages.

[0005] A fuel cell stack with an external medium guide is described in JP 2012 256 498 A. In this case, the medium is also conveyed from the edge from which it is discharged again.

[0006] DE 10 2010 024 316 A1 describes a seal for a bipolar plate of a fuel cell, in which a medium inlet and a medium outlet are formed. The seal is partially elastically deformable, so that it can be prefabricated as a separate component and the bipolar plate can be inserted into the seal by temporarily stretching the seal. Instead of stretching, the seal can also be sprayed.

[0007] JPS 60-109180 describes a fuel cell stack in which an external medium guide is screwed onto the plate stack in such a way that the medium flows through the stack in cross-convection operation.

[0008] US 2005 / 0089736 A1 also describes a fuel cell stack with an external medium guide, with which a cross-convection operation can be achieved.

[0009] Finally, US 2011 / 0318666 A1 also describes a corresponding arrangement of external tubes on a fuel cell stack, which external tubes bring about a cross-convection operation. Summary of the invention

[0010] It is therefore an object of the present invention to provide a fuel cell system in which the supply of a medium for the fuel cell stack is simplified.

[0011] The object is achieved by a fuel cell device having the features according to the invention. In particular, the medium guide element is a medium channel which is connectable to the fuel cell stack or is connected to the fuel cell stack in order to guide the medium into or out of the unit cells of the fuel cell stack substantially transversely to the stacking direction.

[0012] This arrangement is advantageous because a material different from the material used for the unit cells or the bipolar plates of the unit cells can be selected for the media guide. In addition, the number of sealing tracks that must be produced to seal the media guide can be reduced. This also reduces the manufacturing complexity.

[0013] Advantageously, the medium guide comprises a guide tab and a guide leg connected to the guide tab. Here, the guide leg is connectable to the fuel cell stack or is connected to the fuel cell stack. Thus, a U-shape can be described, wherein the open end of the "U" shape points to the fuel cell stack and thus guides the medium from the outside to the fuel cell stack. Thus, the medium flows in the medium guide essentially parallel to the stacking direction. The medium enters the fuel cell stack in a direction transverse or lateral to the stacking direction (xy direction).

[0014] For improved sealing, it has proven to be advantageous if the media guide is connected to the fuel cell stack by means of joining wires. These joining wires extend substantially in the stacking direction and are arranged on both sides of the media channel. Preferably, the joining wires also extend over the entire length of the fuel cell stack in the stacking direction (z direction), just like the media guide. By means of the joining wires arranged on the outer edges of the fuel cell stack, a sealing of the media guide with respect to the environment can be achieved. The material of the joining wires is preferably selected so that the media guide is connected to the fuel cell stack in a material-fitting manner; the media guide is thereby bonded to the fuel cell stack.

[0015] In order to realize a fuel cell stack with high efficiency, it is meaningful that the unit cell has an active area and an edge area located outside the active area, in which the one or more media channels are configured to guide at least one medium into or out of the active area. The active area is essentially the area in which the electrochemical reaction of the fuel cell takes place. In particular, the active area is delimited on the peripheral side by an inactive edge area. The edge area is essentially provided for producing a seal between two adjacent bipolar plates and in particular providing the media channel for conveying a medium, such as a reaction medium or a cooling medium.

[0016] In this context, it has proven to be advantageous if the unit cell comprises a first bipolar plate having a first medium inlet channel and a first medium outlet channel, and a first flow field connecting the first medium inlet channel to the first medium outlet channel, through which, for example, the reaction medium can be conveyed to the membrane electrode assembly located in the active region.

[0017] In order to supply the second medium to the membrane electrode assembly, it is expedient for the unit cell to include a second bipolar plate having a second medium inlet channel and a second medium outlet channel. The second medium inlet channel and the second medium outlet channel are connected to each other via a second flow field.

[0018] In order to additionally seal the cathode relative to the anode of the membrane electrode assembly, it is advantageous if the sealing structure has a sealing edge which seals the membrane electrode assembly laterally.

[0019] Furthermore, the fuel cell device, which is to be manufactured simply, is also characterized in that a plurality of media guides are provided. These media guides are preferably subdivided into a first media conveying member for conveying a first reaction medium and a first media discharge member for discharging at least part of the consumed first reaction medium. Furthermore, the plurality of media guides are subdivided into a second media conveying member for conveying a second reaction medium and a second media discharge member for discharging at least part of the consumed second reaction medium. Thus, the two reaction media are guided in these fuel guides laterally along the fuel cell stack, i.e. outside the stack, wherein the two reaction media can enter or leave the unit cells of the fuel cell stack perpendicularly to the stacking direction and therefore transversely.

[0020] In order to additionally guide the coolant outside the stack along the fuel cell stack and to guide the coolant laterally into the cells or between two cells into the fuel cell stack, it has proven useful to further subdivide the medium guide into a coolant supply element and a coolant discharge element. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be described in detail below with reference to the exemplary embodiments shown in the accompanying drawings.

[0022] Figure 1 A fuel cell device is shown in a perspective view,

[0023] Figure 2 The (first) bipolar plate of a unit cell is shown in a top view,

[0024] Figure 3 Shows Figure 2 The III-III section,

[0025] Figure 4 The top view shows the composite layer with applied Figure 2 The (first) bipolar plate,

[0026] Figure 5 Shows Figure 4 VV section (unextruded state),

[0027] Figure 6 Shows Figure 4 a (first) bipolar plate having a fuel cell device applied thereto,

[0028] Figure 7 Shows Figure 6 Section VII-VII of (unextruded state),

[0029] Figure 8 shows a connection layer with applied Figure 6 Configuration,

[0030] Fig. 9 Shows Figure 8 IX-IX section (unextruded state),

[0031] Fig.10 A unit cell of a fuel cell stack with a (second) bipolar plate is shown in a top view,

[0032] Fig.11 The (second) bipolar plate is shown in a bottom view, ie in a view of the surface of the second bipolar plate facing the membrane electrode assembly,

[0033] Fig.12 The stereogram shows the Fig.10 The corresponding plurality of unit cells form a fuel cell stack,

[0034] Fig.13 Shows Fig.10 XIII-XIII cross-sectional view through a plurality of unit cells stacked on each other (extruded state),

[0035] Fig.14 Shows Fig.10 XIV-XIV cross-sectional view through a plurality of unit cells stacked on each other (extruded state),

[0036] Fig.15 The cross section extending perpendicular to the stacking direction is shown. Fig.12 a cross-section of a fuel cell stack having a bonding wire disposed thereon, and

[0037] Fig.16 The cross section extending perpendicular to the stacking direction is shown. Figure 1 Cross section of a fuel cell device.

[0038] It should be pointed out in advance that the dimensions, dimensional relationships and ratios of the illustrated diagrams are not fixed and may vary. In particular, in the sectional views, the individual layers are shown in such a way that it is possible to understand in what relative position and in what order these individual layers are stacked on each other. DETAILED DESCRIPTION

[0039] exist Figure 1 1 shows a fuel cell device 1 having a fuel cell stack 12. The fuel cell stack 12 is formed by a plurality of unit cells 11 stacked one on top of the other in a stacking direction (z direction). These unit cells 11 each have one or more medium channels 8 and a membrane electrode assembly 2. Each of the membrane electrode assemblies 2 in these unit cells 11 includes a cathode, an anode, and an ion-conducting membrane arranged between the cathode and the anode.

[0040] The fuel cell device 1 also has a medium guide 22 extending parallel to the stacking direction, and the medium guide 22 is connected to the fuel cell stack 12 so as to guide the medium into or out of the medium channel 8 of the unit cell 11 of the fuel cell stack 12 substantially transversely to the stacking direction. To this end, the present fuel cell device 1 includes a plurality of medium guides 22, which are subdivided into a first medium conveying member 22a for conveying a first reaction medium (e.g., hydrogen) to the anode and a first medium discharging member 22b for discharging the first reaction medium (partially) consumed in the unit cell 11. In addition, the medium guide 22 is further subdivided into a second medium conveying member 22c for conveying a second reaction medium (e.g., oxygen or air) to the cathode and a second medium discharging member 22d for discharging the second reaction medium (partially) consumed in the unit cell 11. Finally, the medium guide is further subdivided into a coolant conveying member 22e for conveying a coolant (e.g., liquid water) and a coolant discharging member 22f for discharging the (partially) heated coolant.

[0041] For example, the following is based on Figures 2 to 11 The production or construction of the unit cells 11 of the fuel cell stack 12 shown will be explained.

[0042] exist Figure 2 1 shows a bipolar plate 7 of one of the unit cells 11. The first bipolar plate 7a has an inner active region 3 shown in dashed lines and an outer edge region 5 shown in dashed lines. A plurality of media channels 8 are formed in the edge region 5, which can be subdivided into a first media inlet channel 8a shown on the left side of the figure and a first media outlet channel 8b shown on the right side of the figure.

[0043] In the present case, five of the first medium inlet channels 8a and five of the first medium outlet channels 8b are formed in the first bipolar plate 7a. Other numbers are possible. The first medium inlet channels 8a are in fluid communication with the first medium outlet channels 8b via the first flow field 13a. The flow field 13a is located in the active region 3 and can supply the reaction medium to the adjacent membrane electrode device 2. Figure 2 In the example of the flow field 13a, a plurality of guides or walls 14 are provided for uniformly distributing the reaction medium over the surface of the membrane electrode assembly 2. However, other types of flow fields 13a may also be used, such as flow fields in which the flow of the reaction medium is guided in a meandering manner over the area of ​​the active surface. In addition, the spacing of the walls 14, the walls or the tabs may also vary. The depth of the channels formed by adjacent walls 14 may also be implemented to be different depths and may vary.

[0044] As from Figure 3 , Figure 2 It can be seen from the III-III section of FIG. 1 that a flow field 13 c is also formed on the side of the first bipolar plate 7 a facing away from the membrane electrode assembly 2 , and is used to allow other media, such as a coolant, to flow through.

[0045] like Figure 4 As shown, a composite layer 15, in particular a bonding layer, is applied to the first bipolar plate 7a in the edge region 5. The composite layer 15 is formed in multiple parts or has a recess 16 in the region of the media channels 8a, 8b. The recess 16 ensures that the media inlet channel 8a and the media outlet channel 8b are not sealed and allow the media to pass therethrough later.

[0046] The composite layer 15 arranged in the edge region 5 extends along the long edge 17a of the first bipolar plate 7a so that a flush end is produced with the edge region 5 predetermined by the size of the bipolar plate 7. The active surface or active region 3 is sealed against the environment by the composite layer 15, wherein the material of the composite layer 15 is selected in such a way as to ensure this sealing function. Figure 5 ,Right now Figure 4It can be seen in the VV section of the composite layer 15 or the bonding material is flush with the bipolar plate 7 along the long edge 17a of the bipolar plate 7. The section of the composite layer 15 located on the short edge 17b is also preferably flush with the bipolar plate 7. The selected illustration of the composite layer 15 is exemplary. The composite layer 15 can be designed to be much thinner than the first bipolar plate 7a.

[0047] exist Figure 6 In the embodiment of the present invention, the fuel cell device having the membrane electrode device 2 is applied or applied to the Figure 4 The active region 3 is substantially predetermined by the dimensions of the membrane electrode assembly 2, which is again indicated by an inner dashed line in the figure. However, the active region 3 extends not only in one plane (xy plane), but also in a stacking direction (z direction) pointing out of or toward the paper plane.

[0048] The active region 3 is the region in which the fuel cell formed by the membrane electrode device 2 performs an electrochemical reaction. In the electrochemical reaction, a fuel (e.g., hydrogen) is transported to the anode, where the fuel is catalytically oxidized to protons while releasing electrons. These protons are transported to the cathode through an ion exchange membrane. The electrons derived from the fuel cell flow through electrical consumers, preferably to an electric motor for driving a vehicle or to a battery pack. The electrons are then directed to the cathode. At the cathode, an oxidizing medium (e.g., oxygen or oxygen-containing air) is reduced to anions by absorbing electrons, and these anions react directly with protons to form water.

[0049] In order to ensure that the fuel reaches the anode directly or that the oxidizing medium reaches the cathode directly, a sealing structure 4 is assigned to the membrane electrode assembly 2 laterally. Here, the combination of the membrane electrode assembly 2 and the sealing structure 4 forms a common fuel cell assembly. Here, the sealing structure 4 includes components that extend into the edge region 5 or even protrude beyond the edge region 5. Therefore, these components are arranged outside the active region 3. In other words, the edge region 5 delimits the active region 3 in the radial or lateral direction or on the peripheral side.

[0050] It can be seen that the sealing structure 4 includes a sealing tongue 6 extending into or beyond the edge region 5, which is used to axially and gas-tightly cover the medium channel 8 constructed in the adjacent bipolar plate 7 and located in the edge region 5. The fuel cell device shown here has a total of four sealing tongues 6. Two of the sealing tongues 6 are arranged on the shorter edges 9a of the membrane electrode device 2 opposite to each other. The other two sealing tongues 6 are arranged on the long edges 9b of the membrane electrode device 2 opposite to each other and staggered to each other. In the current case, the sealing tongues 6 all have a rectangular shape. However, the polygonal shape of these sealing tongues is also possible, and rounded sealing tongues 6 are also considered.

[0051] The sealing structure 4 and in particular the sealing tongue 6 are formed to be dimensionally stable with respect to pressure loads and / or tensile loads acting axially on the sealing structure 4 and in particular the sealing tongue 6. It can also be seen that the sealing tongue 6 extends beyond the edge region 5. However, it is also possible that one or more of these sealing tongues 6 only extend into the edge region 5, but do not completely cover the edge region 5 or extend beyond it laterally.

[0052] Furthermore, it can be seen that the sealing structure 4 has a sealing edge 10 which seals the membrane electrode assembly 2 laterally. The sealing line formed by the sealing edge 10 seals the membrane electrode assembly 2 against lateral escape of the medium.

[0053] Here, the sealing tongue 6 of the fuel cell device on the left side covers the left medium channel 8 of the first bipolar plate 7a in an axially airtight manner. The right sealing tongue 6 of the fuel cell device covers the right medium channel 8 of the first bipolar plate 7a in an axially airtight manner. In other words, the left sealing tongue 6 is thus formed as a first inlet sealing tongue 6a, which is used to cover the first medium inlet channel 8a axially and airtightly on the left side. Correspondingly, the right sealing tongue 6 is formed as a first outlet sealing tongue 6b, which is used to cover the first medium outlet channel 8b on the right side axially and airtightly. The sealing tongue 6 arranged on the long edge 17a of the bipolar plate 7a lies flat on the composite layer 15. These sealing tongues 6 can be subdivided into a second inlet sealing tongue 6c and a second outlet sealing tongue 6d.

[0054] As the material of the composite layer 15, a plastic or a plastic mixture can be used which preferably has a lower thermal stability than the plastic or plastic mixture of the sealing structure 4 or the sealing tongue 6. Thus, the sealing tongue 6 can be sunk into the composite layer 15 during the (hot) extrusion process and preferably fuse with the composite layer 15, wherein the sealing tongue 6 retains its dimensional stability. In other words, the melting point of the material of the sealing structure 4 is higher than the melting point of the material of the composite layer 15.

[0055] In the central region, where the active region 3 is located, the sealing structure 4 of the fuel cell device is adapted with respect to its outer contour to the inner contour predetermined by the composite layer 15. In this case, the section of the sealing structure 4 without sealing tongues forms a contact point, contact line 18 or contact surface with the composite layer 15, thereby additionally ensuring the sealing function.

[0056] Figure 7 ,Right now Figure 6The VII-VII section of shows an unextruded cross-sectional view of a portion of the unit cell 11. It can be seen that the first sealing tongues 6a, 6b extend beyond the composite layer 15 and form a protrusion 19 with the composite layer 15. Here, the necessary sealing is guaranteed in the lateral direction. Here, the selected illustration should not be understood as being completely proportional. The thickness of each layer can vary, especially after a connection process or a joining process (hot pressing process), after which each layer appears to be a single common layer or can act like a single common layer. Then, the area where the recess 16 is located between the inlet sealing tongue 6a and the channel 8 is also minimized, so that the inlet sealing tongue 6a covers the channel 8 axially. The medium can be transported to the membrane electrode device 2 laterally and in the stacking direction below the first inlet sealing tongue 8a. Then, the (partially) consumed medium can leave the unit cell 11 of the fuel cell stack 12 laterally and in the stacking direction below the first outlet sealing tongue 8b.

[0057] exist Figure 8 In the embodiment, a connecting layer 20 is applied to the first inlet sealing tongue 6a and the first outlet sealing tongue 6b. The connecting layer 20 should be understood as another bonding layer. The composite layer 15 and the connecting layer 20 ensure that the first bipolar plate 7a is firmly connected to the second bipolar plate 7b in the stacking direction. The composite layer 15 and the connecting layer 20 form an overlap 21 so that the two layers have a contact surface in the stacking direction. This ensures the sealing function. Fig. 9 ,Right now Figure 8 The overlap 21 can be seen in more detail in the section IX-IX of FIG. Here too, the unpressed state is shown, which is not entirely true to scale but is intended to illustrate the arrangement of the stack of individual layers.

[0058] The second bipolar plate 7b can now be applied to the composite layer 15 and the connecting layer 20 connected to the composite layer 15 to complete the unit cell 11. Fig.10 The first bipolar plate 7a and the second bipolar plate 7b can be joined to each other via a joining layer, so that a unit cell equipped with at most small protrusions is formed by the first bipolar plate 7a, the fuel cell device and the second bipolar plate 7b. However, the individual layers of the unit cell 11 are preferably connected without edges or offsets in the stacking direction, so that the joining line 25 to be discussed below can be applied or arranged in a simple manner.

[0059] Like the first bipolar plate 7a, Fig.10 and 11 The second bipolar plate 7b shown in FIG. 1 also has a flow field 13c for conducting a cooling medium on its side facing away from the membrane electrode assembly 2. The flow field 13c is located substantially in the active region 3. The flow field 13c is in fluid communication with the coolant inlet channel 8e and the coolant outlet channel 8f.

[0060] However, the second bipolar plate 7b has one or more second medium inlet channels 8c and one or more second medium outlet channels 8d on its side facing the membrane electrode assembly 2 ( Fig.11 In addition, the second bipolar plate 7b includes a second flow field 13b in fluid communication with the second medium inlet channel 8c and the second medium outlet channel 8d, and one of the reaction media can be transported to the membrane electrode device 2 via the second flow field 13b.

[0061] exist Fig.12 , a fuel cell stack 12 formed of a plurality of unit cells 11 is shown. The advantage of the fuel cell stack 12 is that the bipolar plate 7 can be designed to have smaller dimensions than known bipolar plates, thereby reducing the manufacturing costs of the fuel cell stack 12. In the present case, the bipolar plate 7 is formed into a rectangular shape, wherein the present invention is not dependent on the exact shape of the bipolar plate 7, but can be applied without restriction to any shape having a contour such as a circular or arc shape.

[0062] Fig.13 Shown along Fig.10 The XIII-XIII section of FIG. 1 is an exemplary cross-sectional view through the fuel cell stack 12. It can be seen that the composite layer 15 touches or contacts both the first bipolar plate 7a and the second bipolar plate 7b after the bonding process or the hot pressing process, wherein the bipolar plates 7 are connected to each other or bonded to each other via the composite layer 15. It should also be seen that the second medium inlet channel 8c is axially airtightly covered by the second inlet sealing tongue 6c extending into or beyond the edge region 5. The same is true on the opposite side of the second bipolar plate 7b, where a second outlet sealing tongue 6d extending into or beyond the edge region 5 is provided for axially airtightly covering the second medium outlet channel 8d. Fig.12 It can also be seen that the second reaction medium is guided to the membrane electrode assembly 2 laterally and in the stacking direction above the sealing structure 4. Correspondingly, the (partially) consumed second reaction medium is also guided out of the unit cell 11 or the fuel cell stack 12 laterally again above the sealing structure 4 in the stacking direction.

[0063] Then, the second bipolar plate 7b of the first cell 11 and the first bipolar plate 7a of the other cells 11 form a complete channel cross section for passing the cooling medium. In other words, the second bipolar plate 7b of the first cell 11 and the first bipolar plate 7a of the other cells 11 then also form the coolant inlet channel 8e and the coolant outlet channel 8f. Here, the second bipolar plate 7b of the first cell 11 and the first bipolar plate 7a of the other cells 11 can also be joined to each other with a bonding agent or a bonding medium. Alternatively, a one-piece design made generatively of adjacent bipolar plates 7 is also possible.

[0064] Fig.14 Shown along Fig.10 1 is an exemplary cross-sectional view of the XIV-XIV section through the fuel cell stack 12. It should be seen that the second bipolar plate 7a is applied to the connecting layer 20 and the composite layer 15 in the stacking direction. It should also be seen that the first reaction medium is transported to the membrane electrode device 2 in the stacking direction under the sealing structure 4. Here, the first medium inlet channel 8a is axially airtightly covered by the first inlet sealing tongue 6a. The first reaction medium is transported laterally with respect to the stacking direction or in a transverse direction with respect to the stacking direction. Correspondingly, the (partially) consumed first reaction medium is also guided out again from the unit cell 11 or the fuel cell stack 12 laterally or laterally in the stacking direction under the sealing structure 4.

[0065] exist Fig.15 A cross-sectional view through the fuel cell device 1 is shown, which corresponds essentially to the cross-sectional view according to Fig.10 1. It should be seen, however, that now the joining wires 25 are placed on the fuel cell stack 12 or its unit cells 11, which extend essentially in the stacking direction. The joining wires 25 extend along the entire or whole fuel cell stack 12. The joining wires 25 are arranged on the left and right sides of the media channel 8, i.e. on both sides of the media channel 8, so that the joining wires seal the media channel 8 relative to the environment. In the case of the joining wires 25, the same materials as the composite layer 15 or the connecting layer 20 are considered, so that in the case of the joining wires 25, the joining layer can also be discussed. Different materials can be used for the joining wires 25. Now the media guide 22 can be applied to these joining wires 25, thereby connecting the media guide to the fuel cell stack 12.

[0066] This should be Fig.16 . The medium guide 22 shown here has a guide tab 23 and two guide legs 24a, 24b connected to the guide tab at the end. Each guide leg 24a, 24b is connected to the fuel cell stack 12 by means of one of the bonding wires 25; preferably adhesively bonded. The open side of the medium guide 22 points to the fuel cell stack 12, so that the medium flowing through the medium guide can enter the unit cell 12 laterally. The cross-section of these medium guides is basically formed as a rectangle, but other shapes can be used. The medium channel 22 is preferably formed by a plastic that is particularly stable in shape. In the case of using electrically insulating bonding wires 25, one or more of the medium channels 22 can even be formed by metal.

[0067] The present design of the fuel cell device 1 allows the edge region 5 to be designed as narrow as possible in order to save expensive material of the bipolar plate 7. The outer medium guide 22 can also be made of a different material than the bipolar plate 7 and thus be manufactured more cheaply. The peripheral seal around the medium guide 22 can be omitted. However, the selected configuration still ensures that each unit cell 11 is securely sealed and allows the active area 3 to be maximized compared to the known unit cells 11.

[0068] Reference numerals list

[0069] 1Fuel cell equipment

[0070] 2Membrane Electrode Assembly (MEA)

[0071] 3 Active Area

[0072] 4 Sealing structure

[0073] 5. Marginal Area

[0074] 6 sealing tongue

[0075] 6a First inlet sealing tongue

[0076] 6b First outlet sealing tongue

[0077] 6c Second inlet sealing tongue

[0078] 6d Second outlet sealing tongue

[0079] 7 Bipolar Plate

[0080] 7a First bipolar plate

[0081] 7b Second bipolar plate

[0082] 8 media channels

[0083] 8a First medium inlet channel

[0084] 8b First medium outlet channel

[0085] 8c Second medium inlet channel

[0086] 8d Second medium outlet channel

[0087] 8e Coolant inlet channel

[0088] 8f Coolant outlet channel

[0089] 9a Short edge of membrane electrode assembly

[0090] 9b The long edge of the membrane electrode assembly

[0091] 10 Sealing ring

[0092] 11-cell battery

[0093] 12 Fuel Cell Stack

[0094] 13a The first flow field

[0095] 13b Second flow field

[0096] 13c flow field (cooling medium)

[0097] 14 walls

[0098] 15 composite layers

[0099] 16 Notches

[0100] 17a Long edge of bipolar plate

[0101] 17b Short edge of bipolar plate

[0102] 18 contact line

[0103] 19 protrusion

[0104] 20 connection layers

[0105] 21 Overlap

[0106] 22 Media Guide

[0107] 22a first medium conveying member

[0108] 22b first medium discharge member

[0109] 22c Second medium conveying member

[0110] 22d Second medium discharge member

[0111] 22e Coolant delivery parts

[0112] 22f coolant discharge piece

[0113] 23 Guide tab

[0114] 24a Lead leg (left)

[0115] 24b Leading leg (right)

[0116] 25 bonding wire

Claims

1. A fuel cell device (1), comprising a fuel cell stack (12), the fuel cell stack being formed by a plurality of unit cells (11) stacked one on top of the other in a stacking direction, the unit cells each comprising one or more media channels (8) and a membrane electrode assembly (2) arranged between two bipolar plates (7), the membrane electrode assembly comprising a cathode, an anode and a membrane arranged between the cathode and the anode, and the fuel cell device comprising a plurality of media guides (22) extending substantially parallel to the stacking direction, wherein the plurality of media guides (22) are connected to the bipolar plates (7) of the fuel cell stack (12) in such a way as to guide a plurality of media into or out of the media channels (8) of the unit cells (11) of the fuel cell stack (12) substantially transversely to the stacking direction, wherein each of the plurality of media guides (22) comprises a guide tab (23) and a guide leg (24a, 24b) connected to the guide tab, and wherein the guide leg (24a, 24b) is connected to the fuel cell stack (12), wherein: The plurality of medium guides (22) include a coolant conveying member (22e) connected to a first long edge of the bipolar plate (7), wherein the plurality of medium guides (22) include a coolant discharging member (22f) connected to a second long edge of the bipolar plate (7), wherein the plurality of medium guides (22) include a first medium conveying member (22a) connected to a first short edge of the bipolar plate (7) for conveying a first reaction medium, wherein the plurality of medium guides (22) include a first medium discharging member (22b) connected to the second short edge of the bipolar plate (7) for discharging at least part of the consumed first reaction medium, and wherein the plurality of medium guides (22) include a first medium conveying member (22a) connected to a first short edge of the bipolar plate (7) for discharging at least part of the consumed first reaction medium. A second medium conveying member (22c) connected to the long edge is used to convey a second reaction medium, and the plurality of medium guides (22) include a second medium discharge member (22d) connected to the second long edge of the bipolar plate (7) for discharging at least partially consumed second reaction medium, characterized in that the plurality of medium guides (22) are formed of a material different from that of the unit cell (11) or the bipolar plate (7), and each of the guide legs (24a, 24b) of the plurality of medium guides (22) is engaged with the fuel cell stack (12), wherein the membrane electrode device (2) is laterally allocated with a sealing structure (4) for axially airtightly covering the one or more medium channels (8).

2. The fuel cell device (1) according to claim 1, characterized in that The plurality of media guides (22) are connected to the fuel cell stack (12) by means of joining lines (25), which extend substantially in the stacking direction and are arranged on both sides of the media channel (8).

3. The fuel cell device (1) according to claim 1 or 2, characterized in that: The unit cell (11) has an active region (3) and an edge region (5) located outside the active region (3), in which the one or more medium channels (8) are designed to guide at least one medium into or out of the active region (3).

4. The fuel cell device (1) according to claim 1 or 2, characterized in that: The unit cell (11) comprises: a first bipolar plate (7a) having a first medium inlet channel (8a) and a first medium outlet channel (8b), and a first flow field (13a) connecting the first medium inlet channel (8a) and the first medium outlet channel (8b).

5. The fuel cell device (1) according to claim 4, characterized in that The unit cell (11) comprises: a second bipolar plate (7b) having a second medium inlet channel (8c) and a second medium outlet channel (8d), and a second flow field (13b) connecting the second medium inlet channel (8c) and the second medium outlet channel (8d).

6. The fuel cell device (1) according to claim 1, characterized in that The sealing structure (4) has a sealing edge (10) for transversely sealing the membrane electrode assembly (2).

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