Fuel cell and its manufacturing process

Abstract

Fuel cell and its manufacturing process. Fuel cell (1), comprising: stacked plates (10, 30, 50, 70), each plate having a respective heat exchange edge to form a heat exchange face (5); an outer manifold, fluidically connected to the heat exchange face; and a manifold seal (90), framing the heat exchange face (5) to ensure a fluidic connection seal. To make the manifold seal more precisely shaped and easier to apply, each plate has a respective centering notch, adjacent to the heat exchange edge, to form a centering groove (6) bordering the heat exchange face. The manifold seal includes a longitudinal gasket portion (91) formed in the centering groove and ensuring a fluidic connection seal. Figure for the abstract: Figure 2

Description

Title of the invention: Fuel cell and its manufacturing process

[0001] The present invention relates to a fuel cell and a method for manufacturing such a fuel cell.

[0002] US2001055708A1 describes a fuel cell comprising a ho stack The stack consists of electrochemical cell components, including anodic and cathodic fluidic field plates, anodic and cathodic supports, anodic and cathodic catalysts, and proton exchange membranes. The stack is supplied with a reactive gas, such as oxygen or hydrogen, via a manifold positioned on top of the stack. A sealing system is interposed between the manifold and the stack. Since the component edges are in irregular positions—protruding or recessed relative to each other—the sealing system comprises a first part forming low-temperature cross-linked silicone bridges that conform to the shape of the protruding and recessed edges to create a flat and regular surface.The sealing system includes a second part, formed by a layer of foamed silicone, which is interposed between the flat and regular surface of the first part and the lower surface of the collector, extending over the entire perimeter of the collector.

[0003] However, in practice, the need to use low-viscosity silicone so that it can perfectly conform to the irregularities of the stack and form bridges may mean that the silicone spreads widthwise, so that the resulting joint, although relatively flat on the surface, is generally quite wide and imprecise in shape. This wide spreading of the joint is likely to accidentally block part of the heat exchange face between the stack and the collector, thus reducing the efficiency of the fuel cell.

[0004] The invention aims to resolve the drawbacks of the prior art, by proposing a new fuel cell whose manifold seal has a better controlled shape in which the application of the manifold seal is facilitated.

[0005] The invention relates to a fuel cell, comprising:

[0006] - a stack, comprising plates, the plates of the stack comprising flow field plates and membrane-electrode plates are stacked in a specific stacking direction to form electrochemical cells, each plate being oriented perpendicular to the stacking direction and lying flat against the adjacent plate, each plate comprising a respective exchange edge, the exchange edges being parallel to each other. and together forming an exchange face belonging to the stacking, the exchange face extending parallel to the stacking direction;

[0007] - an external collector, which is fluidly connected to the stack by being brought against the stack so as to cover the exchange face, for the exchange of an operational fluid between the external manifold and the stack via the exchange face; and

[0008] - a manifold gasket, which frames the exchange face and is interposed between the stack and the outer collector, to ensure a tight fluid connection between the outer collector and the stack.

[0009] According to the invention:

[0010] - each plate includes a respective centering notch, adjacent to the edge of exchange, the centering notches together forming a centering groove belonging to the stack, the centering groove bordering the exchange face and extending parallel to the stacking direction; and

[0011] - the manifold seal includes a longitudinal seal portion, which is parallel to the stacking direction, which is formed in the centering groove, so that the longitudinal joint portion is interposed between the stack and the outer manifold to ensure the sealing of the fluidic connection between the outer manifold and the stack.

[0012] One idea underlying the invention is to form the manifold seal within the centering groove, such that the manifold seal, received inside the centering groove, has a low tendency to protrude laterally during its formation, particularly if the material used to form the manifold seal has very low viscosity. Since the shape of the manifold seal is well controlled, it is easier to form a seal that conforms to the centering notches of the plates, even if some notches are recessed or protrude relative to each other. Sealing against the operating fluid is therefore easier to ensure.

[0013] Another advantage is that certain centering notches can be used to ensure centering of the plate during stack manufacturing. In other words, during the stacking of the plates to form the stack, and while the manifold joint has not yet formed, a centering rail can be temporarily installed. This rail mechanically cooperates with certain centering notches and thus serves as a template to ensure that the corresponding plates are correctly positioned, transversely to the stacking direction. The centering rail is oriented parallel to the stacking direction. During stacking, at least some plates, whose centering notch mechanically cooperates with the rail, are guided to slide along the stacking direction along the centering rail. For the other plates, the rail can pass through the centering notch in the direction stacking. Once the plates are stacked, the centering rail is removed, leaving the centering notches free for the formation of the manifold seal within them. The centering notches thus serve both to center the plates and to receive the longitudinal seal portion.

[0014] Preferably, at least one of the flow field plates forms exchange orifices, formed at the exchange edge of the flow field plate, to open onto the surface of the exchange face and be covered by the outer collector, the exchange of operational fluid between the outer collector and the stack being carried out via the exchange orifices.

[0015] Preferably, the stacking plates comprise a respective secondary edge, parallel to the exchange edge and connected to the exchange edge by the centering notch.

[0016] Preferably, for at least one of the plates of the stack, the exchange edge is projecting outwards from the stack relative to the secondary edge.

[0017] Preferably, for at least one of the membrane-electrode plates, the secondary edge of the membrane-electrode plate protrudes outwards from the stack, relative to the secondary edge of the adjacent flow field plates.

[0018] Preferably, the flow field plates comprise primary flow field plates and secondary flow field plates. Preferably, at least one of the primary flow field plates is adjacent to one of the secondary flow field plates to form, with said secondary flow field plate, a bipolar plate. Preferably, for at least one of the bipolar plates, the exchange edge of the primary flow field plate and the exchange edge of the secondary flow field plate are mutually flush. Preferably, for at least one of the bipolar plates, the centering notch of the primary flow field plate is recessed towards the interior of the stack relative to the centering notch of the secondary flow field plate.

[0019] Preferably, the centering notch of at least one of the membrane-electrode plates is flush or recessed towards the inside of the stack, relative to the centering notch of the adjacent secondary flow field plate, and protrudes towards the outside of the stack, relative to the centering notch of the adjacent primary flow field plate.

[0020] Preferably, for at least one of the membrane-electrode plates, the exchange edge of the membrane-electrode plate protrudes outwards from the stack, relative to the exchange edge of the adjacent flow field plates.

[0021] Preferably, the stack further includes peripheral seals, each peripheral seal being interposed between one of the flow field plates and one of the membrane-electrode plates along the stacking direction.Preferably, each peripheral joint comprises: an exchange edge portion, which is interposed between the exchange edge of the flow field plate and the exchange edge of the membrane-electrode plate along the stacking direction, being flush with the exchange edge of said flow field plate or recessed into the stack relative to the exchange edge of said flow field plate; and a recessed portion, which is interposed between the centering notch of the flow field plate and the centering notch of the membrane-electrode plate along the stacking direction, the recessed portion being recessed into the stack relative to the centering notch of the membrane-electrode plate and being flush with or recessed into the stack relative to the centering notch of the flow field plate.

[0022] Preferably, for at least one of the stacking plates, the centering notch has a profile in the shape of a circular arc, projected into a projection plane that is orthogonal to the stacking direction.

[0023] Preferably, the stacking plates include an end plate, terminating the stacking along the stacking direction.

[0024] Preferably, a transverse groove is formed in the exchange edge of the end plate, the transverse groove being connected to the centering groove by opening into the centering notch of the end plate. Preferably, the manifold seal includes a transverse seal portion, which is perpendicular to the stacking direction, formed in the transverse groove and joined to the longitudinal seal portion, such that the transverse seal portion is interposed between the end plate and the outer manifold to ensure fluidic sealing of the fluidic connection between the outer manifold and the stack.

[0025] The invention also relates to a method for manufacturing the fuel cell as defined above. The method comprises:

[0026] - while the stacking plates are not yet stacked and the joint of collector is not yet formed, installation of a centering rail, which is parallel to the stacking direction and which is suitable to be received in the respective centering notch of the plates;

[0027] - successive stacking of the plates to form the stack while the rail of centering is installed, by guiding the plates by mechanical cooperation of at least one of the centering notches with the centering rail, so that the centering rail ensures centering of the plates transversely with respect to the stacking direction;

[0028] - removal of the centering rail, once the stacking is complete, by moving the rail centering away from the stacking, transversely with respect to the stacking direction;

[0029] - installation of the manifold seal, with the longitudinal seal portion formed in the centering groove, once the stacking has been completed and the centering rail has been removed; and

[0030] - fluidic connection of the external manifold to the stack, once the seal of The manifold was put in place, bringing the outer manifold against the stack so as to cover the exchange face, with the manifold seal interposed, including the longitudinal seal portion, between the stack and the outer manifold, to ensure the sealing of the fluid connection between the outer manifold and the stack.

[0031] Preferably, the installation of the centering rail includes attaching the centering rail to a support plate belonging to the fuel cell. Preferably, the successive stacking of the plates includes stacking one of the plates against the support plate parallel to the stacking direction. Preferably, the removal of the centering rail includes separating the centering rail from the support plate.

[0032] Preferably, the installation of the manifold gasket includes:

[0033] - application of a first bead, made of elastomer in a non-crosslinked state, in the centering groove, to form the longitudinal joint portion; and

[0034] - in-situ crosslinking of the non-crosslinked elastomer of the first cord, while the The first bead has been applied.

[0035] Preferably, the installation of the manifold seal further comprises, once the first bead has been applied: application of a second bead, of elastomer in a non-crosslinked state on the first bead, so that the second bead is projecting outwards from the stack, relative to the exchange face, the elastomer of the second bead having a higher viscosity, at the time the second bead is applied than the viscosity of the elastomer of the first bead, when the first bead is applied.

[0036] The invention and other advantages thereof will become apparent from the following description of embodiments conforming to its principle, made with reference to the accompanying figures in which:

[0037] [Fig-1] Fig. 1 shows a perspective view of a fuel cell according to a method of embodiment of the invention.

[0038] [Fig.2] [Fig.2] is a view similar to [Fig.1], where an external collector has been withdrawn.

[0039] [Fig.3] [Fig.3] is a view similar to [Fig.1], where the external collector and a The manifold gaskets have been removed.

[0040] [Fig.4] The [Fig.4] is a perspective view, from another angle, in this case from below, showing a detail of the [Fig.3].

[0041] [Fig.5] The [Fig.5] is a top view of part of a stack belonging to the fuel cell of figures 1 to 4.

[0042] [Fig.6] [Fig.6] is a view similar to that of [Fig.5], where the manifold seal is further shown.

[0043] [Fig.7] [Fig.7] is a perspective view similar to [Fig.1], showing a manufacturing step of the fuel cell.

[0044] [Fig.8] [Fig.8] is a perspective view similar to [Fig.1], showing another manufacturing step of the fuel cell.

[0045] [Fig.9] [Fig.9] is a perspective view similar to [Fig.1], showing another manufacturing step of the fuel cell.

[0046] Figures 1 to 3 show a fuel cell 1 according to an embodiment of the invention. The fuel cell 1 comprises a stack 2, shown in more detail in Figures 4 to 6. The stack 2 comprises primary flow field plates 10, secondary flow field plates 30, membrane-electrode plates 50 and, preferably, terminal plates 70 and peripheral seals 80. The cell 1 also comprises an outer manifold 100, visible in [Fig. 1], and a manifold seal 90, visible in Figures 2 and 6. The cell 1 also advantageously comprises a compression system visible in Figures 1 to 3, comprising, for example, support plates 111 and 112, tie rods 113 and springs 114.

[0047] For the manufacture of the stack 1, and in particular the centering of the different plates 10, 30, 50 and 70, a peripheral centering jig 130 shown in figures 7 to 9 is used, including centering rails 131, which is at least partially removed once the stacking 2 is completed.

[0048] A stacking direction Z2 is defined, according to which the plates 10, 30, 50 and 70 as well as the joints 80 are stacked to constitute the stack 2. The direction Z2 is perpendicular to the plates 10, 30, 50 and 70 and fixed with respect to the stack 2.

[0049] As shown in Figures 1 to 3, the support plates 111 and 112 are arranged on either side of the stack 2 along the direction Z2. The springs 114 are interposed, along the direction Z2, between the stack 2 and the support plate 112. The support plate 111 bears against the stack along the direction Z2. The stack 2 bears against the springs 114, which are distributed over the surface of the support plate 112. The springs 114, interposed between the support plate 112 and the stack 2, bear against the plate 112 along the direction Z2. The tie rods 113, which are each parallel to the direction Z2, are distributed around Stack 2 is secured by connecting the support plates 111 and 112 so as to maintain them in position relative to each other along the Z2 direction, thus keeping stack 2 under compression along the Z2 direction by the springs 114. The springs 114 advantageously accommodate dimensional variations of stack 2 along the Z2 direction, which may occur during stack use, particularly under the effect of thermal stresses. In this example, six tie rods 113 and eight springs 114 are provided; however, a different number of these elements may be used. Alternatively, another type of compression system may be provided.For example, the compression system could alternatively include support plates on either side of the stack, with the entire stack and support plates housed in a casing, and springs interposed between one face of the casing and at least one of the support plates to compress the stack. The principle of such an alternative compression system is described, for example, in document WO2007 / 080472. Other compression systems are described in document US20090162728 or, without springs, in document US20100261088, or in document EP1597786.

[0050] Each plate 10, 30, 50, and 70 is flat, lying in a respective plane perpendicular to the direction Z2. The plates 10, 30, 50, and 70 are parallel to each other and to the plates 111 and 112. As can be seen more clearly in Figures 3 and 4, each plate 10, 30, 50, or 70 is positioned flat against the adjacent plate, that is, against the immediately following plate. Being thus positioned flat, the plate 10, 30, 50, or 70 is superimposed, edge to edge, with the adjacent plate, optionally with one of the joints 80 interposed between the two adjacent plates. More specifically, each peripheral joint 80 is interposed between one of the membrane-electrode plates 50, and one of the flow field plates 10 or 30. Each peripheral joint 80 extends flat between the plates concerned, along a plane perpendicular to the stacking direction Z2.In the illustrated example, the adjacent flow field plates 10 and 30 are superimposed without the interposition of a peripheral seal 80 between them.

[0051] The individual plates of the stack 2 are arranged in a specific order along the stacking direction Z2, to form groups of adjacent plates, each group of adjacent plates forming a respective electrochemical cell. Each electrochemical cell of the stack 2 comprises, in this order along the Z2 direction, a secondary flow field plate 30, an optional peripheral seal 80, a membrane-electrode plate 50, another optional peripheral seal 80, and a primary flow field plate 10. For the operation of the electrochemical cells, the stack 2 is designed to be supplied with operating fluids, including a cathodic reactive fluid, comprising, for example, Dihydrogen, an anodic reactive fluid, including, for example, dioxygen possibly contained in air, and, if necessary, a cooling fluid. Within each electrochemical cell, the cathodic reactive fluid reacts with the anodic reactive fluid to produce electricity. The cooling fluid is used to cool stack 2. These operational fluids and / or the products of their reaction are also intended to be removed after they have passed through stack 2.

[0052] In the present example, for the sake of simplicity, only nine electrochemical cells have been shown. However, in practice, the fuel cell 1 may have a higher number of cells, for example between fifty and five hundred.

[0053] Each plate 10, 30, 50, and 70 has an outer perimeter 3, which extends along a plane orthogonal to the direction Z2. Each plate 10, 30, 50, and 70 extends exclusively within its outer perimeter 3. Here, each outer perimeter 3 is generally rectangular in shape. Advantageously, the outer perimeter 3 of each plate of the same type in the stack 2 is of the same shape, or a similar shape, and is superimposed along the stacking direction Z2 with the outer perimeter 3 of all the other plates of the same type, that is, aligned along the direction Z2. For example, all the membrane-electrode plates 50 have an identical outer perimeter 3 that is superimposed along the stacking direction Z2 with the outer perimeter 3 of the other membrane-electrode plates 50.For example, all primary flow field plates 10 have an identical outer perimeter 3, overlapping along the stacking direction Z2 with the outer perimeter 3 of the other primary flow field plates 10. The perimeter 3 of the plates 10 may differ from that of the plates 50, and so on. In particular, the outer perimeter 3 of plates of one type is expected to be, in whole or in part, recessed inwards or projecting outwards from the stack 2, relative to the outer perimeter of plates of another type. For example, the outer perimeter 3 of the membrane-electrode plates 50 is expected to project outwards from the stack 2 relative to the outer perimeter 3 of the flow field plates 10.

[0054] The combination of the outer perimeters 3 of all the plates 10, 30, 50, and 70 of the stack forms different sides 4 of the stack 2, parallel to the direction Z2, here four sides 4, since the outer perimeters 3 of the plates of the stack 2 have a generally rectangular shape. Since some parts of the outer perimeter 3 of the plates 10, 30, 50, and 70 are recessed or protruding, the sides 4 are irregular, the recessed perimeters 3 forming transverse grooves, perpendicular to the stacking direction Z2, the protruding perimeters 3 forming ridges, perpendicular- cular to the stacking direction Z2 and parallel to the grooves.

[0055] As can be more clearly seen in Figures 2 and 3, at least one of the sides 4 of the stack 2 forms at least one exchange face 5, at least one centering groove 6, and at least one secondary face 7. For example, at least one of the sides 4 of the stack 2 forms a single exchange face 5, two centering grooves 6, and two secondary faces 7. The present description and the drawings show only one of the sides 4 of the stack 2 provided with such elements. However, it is preferable that one or more other sides 4 have such elements, or at least centering grooves 6. Typically, two opposite sides 4 of the stack 2 will be provided with such elements, to form an inlet and an outlet for the same given working fluid.It is also possible to provide, in a side 4, two exchange faces 5 arranged side by side along the tangential direction of said face which is perpendicular to the stacking direction Z2, with in this case, for example, three or four centering grooves 6 and two or three secondary faces 7. .

[0056] In addition to said at least one exchange face 5, the stack may include, in a known manner, one or more internal galleries, or internal collectors, each internal gallery being formed of superimposed orifices arranged in the stack of plates, for the circulation and distribution of one or more other of the operational fluids.

[0057] For each exchange face 5, a normal direction Y2 is defined, perpendicular to the face 5 and to the direction Z2 and directed outwards from the stack 2, and a tangential direction X2 is defined, parallel to the exchange face 5 and perpendicular to the direction Z2.

[0058] Preferably, the exchange face 5, the grooves 6 and the secondary faces 7 extend from one end to the other of the stack 2 along the direction Z2, and are parallel to the direction Z2.

[0059] Each centering groove 6 extends parallel to the direction Z2 and is recessed in the stack 2 so as to be open along the normal direction Y2. The exchange face 5 is located between the two grooves 6, being delimited by the grooves 6 along the tangential direction X2. Each groove 6 is located between the exchange face 5 and one of the secondary faces 7. Along the tangential direction X2, the secondary face 7 is preferably delimited by the groove 6 and extends, for example, to one end of the side 4. Preferably, the exchange face 5 and the secondary face(s) 7 are parallel to each other and parallel to the tangential direction X2.

[0060] On the same side 4 as that bearing the exchange face 5, the stack also preferably comprises one or more transverse grooves 8, here two transverse grooves 8. Each transverse groove 8 is formed in a recess in the stack 2, so as to be open along the normal direction Y2. Each transverse groove 8 connects the two centering grooves 6 together. For this purpose, each transverse groove 8 preferably extends perpendicularly to the direction Z2, in particular parallel to the direction X2. The exchange face 5 is positioned between the two grooves 8, being delimited by the grooves 8 along the stacking direction Z2. Together, the grooves 6 and 8 frame the exchange face 5 with a closed contour.

[0061] As can be seen in [Fig.2], the manifold seal 90 is preferentially integral with the stack 2, while the manifold 100 is attached to the stack 2, bearing against the seal 90, as shown in [Fig. 1].

[0062] The manifold gasket 90 frames the exchange face 5. For this purpose, the manifold gasket 90 comprises two longitudinal gasket portions 91 and two transverse gasket portions 92. Each longitudinal gasket portion 91, also visible in cross-section in [Fig. 6], extends parallel to the stacking direction Z2. The portions 91 are arranged on either side of the face 5 along the direction X2, each being formed in one of the grooves 6, over the entire height of the face 5 along the direction Z2. Each transverse gasket portion 92 connects the two longitudinal gasket portions 91, extending, for example, parallel to the tangential direction X2. The portions 92 are joined to the portions 91 at each end of the portions 92. Thus, the portions 92 are arranged on either side of the face 5 along the direction Z2.Overall, the manifold joint 90 has a quadrilateral shape, or at least has a closed contour around face 5.

[0063] Preferably, each longitudinal gasket portion 91 completely fills the cross-section of the groove 6 it occupies, along a portion of the groove 6 that runs along the face 5, the portion 91 conforming to the shape of the bottom of the groove 6. Similarly, preferably, each transverse gasket portion 92 completely fills the cross-section of the groove 8 it occupies, along a portion of the groove 8 that runs along the face 5, the portion 92 conforming to the shape of the bottom of the groove 8. As can be seen in [Fig. 6], along the Y2 direction, the gasket 90 protrudes slightly to ensure a watertight contact with the manifold 100. In particular, the longitudinal gasket portions 91 protrude slightly along the Y2 direction out of the grooves 6. In particular, the transverse gasket portions 92 protrude slightly along the Y2 direction out of the grooves 8.

[0064] The heat exchange face 5 is configured to allow the exchange of at least one operating fluid, preferably a single operating fluid, with the external manifold 100. To this end, the external manifold 100 is fluidically connected to the stack 2, in particular by being connected to the heat exchange face 5, preferably exclusively to face 5. To be fluidly connected to the stack 2, the manifold 100 is brought against the stack 2 so as to cover the face exchange 5, as shown in [Fig. 1]. To ensure the sealing of this fluidic connection, the seal 90 is interposed between the manifold 100 and the stack 2, along the direction Y2.

[0065] By "exchange", we mean either an admission of operating fluid into the stack 2 via the exchange face 5, the operating fluid then being supplied by the external collector 100, or an evacuation of operating fluid from the inside of the stack 2 via the exchange face 5, the operating fluid then being collected by the external collector 100. At the level of the face 5, the exchange of operating fluid is carried out parallel to the normal direction Y2.

[0066] In practice, as shown in [Fig. 1], the manifold 100 comprises a connector 101, which, for example, has a funnel shape. A first flared opening covers the face 5 to be fluidically connected to it, and a second, narrower opening is connected to an inlet or outlet line for the operating fluid. The first opening connected to the exchange face 5 is delimited by a closed-contour edge belonging to the connector 101, which extends in the plane X2, Z2 perpendicular to the normal direction Y2, and which advantageously has a shape complementary to that of the grooves 6 and 8. To ensure the sealing of the connection, this closed contour belonging to the manifold comes into contact with the seal 90 all around the face 5, in particular in contact with the longitudinal seal portions 91 and transverse seal portions 92 of the seal 90.The manifold gasket 90 is preferably made of elastomer, for example silicone, which is slightly elastic so that it can conform to the manifold 100 and thus ensure a seal. The closed-contour edge that defines the first opening of the connector 101 therefore has a bearing surface that provides a watertight seal along the entire closed contour against the gasket 90, which thus extends along an identical contour. The bearing surface of the closed-contour edge that defines the first opening of the connector 101 can be a flat surface extending in the plane X2, Z2 perpendicular to the normal direction Y2, thus having the shape of a band following the closed contour. This bearing surface may have one or more raised ribs relative to the plane X2, Z2 perpendicular to the normal direction Y2, preferably one or more raised ribs following said contour, parallel to each other along the contour if there are several.Such ribs extending over the contour can thus be indented into the material of the seal 90, over the entire closed contour, to increase the reliability of the sealing of the contact between the connector 101 and the seal 90.

[0067] The collector 100 may also preferably include a fastening system 102, which is integral with the connector 101 and by means of which the collector 100 can be attached to the stack 1 and / or the stack 2. Here, the fastening system 102 is designed to be attached to the stack 1 by being fixed to the plates 111 and 112. Preferably, the The fixing system 102 includes a base 103, through which the fixing system is fixed to a fixing edge 115, belonging to the plate 111. Preferably, the base 103 is brought against the fixing edge 115 parallel to the normal direction Y2, the fixing edge 115 being parallel and / or in the extension of the exchange face 5, along the direction Z2.

[0068] Preferably, the fastening system 102 comprises a base 104, through which the fastening system is fixed to a fastening edge 116 belonging to the plate 112. Preferably, the base 104 is attached to the fastening edge 116 parallel to the normal direction Y2, the fastening edge 116 being parallel to and / or in line with the exchange face 5, along the direction Z2. The connector 101 is held against the face 5 in the opposite direction to Y2 by the bases 103 and 104. Preferably, at least one of the bases 103 or 104 is allowed to move along the direction Z2 relative to the other base and / or relative to the connector 101, to allow dimensional variation of the stack 2 along the direction Z2 during use.

[0069] At least one of the bases of the fastening system as described above could be fixed to a fastening edge belonging to one or the other of the terminal plates 70 as described below.

[0070] Preferably, the stack 2 comprises exactly two end plates 70, which are provided at the ends of the stack 2, on either side, along the stacking direction Z2. In other words, each end plate 70 terminates the stack along the direction Z2. This does not preclude other plates from edging the stack 2 on either side, edging the plates 70. The end plates 70 are provided to receive the forces applied to the stack 2 by the compression system. In the present example, the stack 2 is supported against the support plate 111 by means of one of these two end plates 70, in the opposite direction to Z2, and the stack 2 is supported against the springs 114 by means of the other of these two end plates 70.Preferably, the terminal plates 70 are electrically insulating, have an electrically insulating coating, or have at least one portion in contact with the stack that is electrically insulating, taking into account the electrical currents involved within the stack 2. It may advantageously be provided that the plate 111, as well as the terminal plate 70 bearing against the support plate 111, are traversed, along the direction Z2, by passages for operational fluid, to supply the stack 2 and / or to evacuate operational fluid from the stack 2. Thus, additional connections for operational fluid can be made via the terminal plate 70, in addition to those made using the exchange face(s) 5 and the external manifold(s) 100.

[0071] Preferably, each membrane-electrode plate 50 is constituted by a membrane-electrode assembly and, in certain embodiments, includes an outer frame forming the outer perimeter 3 of the plate 50. The outer frame is preferably electrically insulating, taking into account the electric currents involved within the stack 2. The membrane-electrode plate 50 also includes a membrane, surrounded by the frame, allowing proton exchange from one face of the plate 50 to the other. The membrane is coated on one face, here the face directed along the Z2 direction, by a layer of cathodic catalyst, itself coated by a layer of cathodic gas diffusion. The membrane is coated on another face, here the face directed in the opposite direction to Z2, by a layer of anodic catalyst, itself coated by a layer of anodic gas diffusion.The membrane of each plate 50 is the site of electrochemical reactions involving the anodic reactive fluid, supplied to the face bearing the anodic catalyst, and the cathodic fluid, supplied to the face bearing the cathodic catalyst, producing an electrical potential difference across the membrane, and ultimately, the electricity of the fuel cell. Alternatively, the outer perimeter 3 of the plate 50 is formed by the membrane itself, and the plate 50 is frameless.

[0072] Preferably, for the manufacture of the cell 1, each membrane-electrode plate 50 is pre-assembled before being added to the stack 2, i.e. that the aforementioned components of the plate 50 are already fixed to each other when the plate 50 is added to the stack 2.

[0073] Preferably, each flow field plate 10 and 30 is electrically conductive, taking into account the electrical currents involved within the stack 2. On one of its faces, each plate 10 and 30 forms a flow field, that is, a plurality of channels traversing the stack 2, transversely with respect to the stacking direction Z2, to guide, within each channel, a flow of working fluid. The channels of the plates 10 and 30 are formed along the gas diffusion layer of the plate 50 adjacent to this plate 10 or 30, so that the working fluid circulating in the channels is brought into contact with the gas diffusion layer and ensures the electrochemical reaction at the adjacent plate 50.

[0074] All the primary flow field plates 10 are dedicated to guiding the circulation of a first operating fluid, for example the cathodic reactive fluid, and have their channels facing the corresponding gas diffusion layer of the plate 50 that is adjacent to this plate 10. Here, this refers to the cathodic diffusion layer of said plate 50. In this sense, the primary flow field plates 10 can be described as polar plates, here cathodic plates. In the example, the The channels of the primary flow field plates 10 face plate 50, which is adjacent to plate 10, in the opposite direction to Z2. For example, the channels of the primary flow field plate 10 are generally oriented parallel to the Y2 direction. Through an electrochemical reaction within the adjacent plate 50, each electrically conductive primary flow field plate 10 is brought to a cathodic electrical potential for the electrochemical cell in question. The peripheral seal 80, interposed between the plate 10 and the adjacent plate 50, ensures the seal between these two plates 10 and 50 to prevent the first operational fluid from escaping from the stack at the level of the outer perimeters 3 of said plates 10 and 50. For this purpose, the seal 80 advantageously forms a closed contour which extends along the perimeters 3, flush or possibly slightly recessed inwards with respect to the perimeters 3.

[0075] All the secondary flow field plates 30 are dedicated to guiding the circulation of a second operating fluid, for example, the anodic reactive fluid, and have their channels facing the corresponding gas diffusion layer of another plate 50, which is adjacent to this plate 30. Here, it is the anodic diffusion layer of said plate 50. The plates 10 and 30, adjacent to each other, therefore separate two plates 50, to which they are respectively adjacent. The secondary flow field plates 30 can be described as polar plates, here anodic. In the example, the channels of the secondary flow field plates 30 face plate 50, which is adjacent to plate 30, along the Z2 direction. In the example, the channels of plate 30 are generally directed either parallel to the Y2 direction or parallel to the X2 direction.By electrochemical reaction within the adjacent plate 50, each electrically conductive plate 30 is brought to an anodic electrical potential for the electrochemical cell in question. The peripheral seal 80, interposed between the plate 30 and the adjacent plate 50, ensures a seal between these two plates 30 and 50 to prevent the second operating fluid from escaping from the stack at the outer perimeters 3 of said plates 30 and 50. For this purpose, the seal 80 advantageously forms a closed contour extending along the perimeters 3.

[0076] In other words, the channels of the flow field plates 10 and 30 of the same electrochemical cell are separated by one of the membrane-electrode plates 50, the channels of the flow field plates 10 and 30 facing this membrane-electrode plate 50 and being surrounded by the peripheral seals 80. From one electrochemical cell to the adjacent electrochemical cell, the channels of plate 10 of the first electrochemical cell face away from the channels of plate 30 of the second electrochemical cell. The adjacent flow field plates 10 and 30, belonging to two neighboring cells, together constitute a plate bipolar. By electrical conduction between these two adjacent plates 10 and 30, the two polar plates are at the same electrical potential.

[0077] It can advantageously be provided that, between the adjacent flow field plates 10 and 30, that is to say, within the bipolar plate, another circulation field is formed by the plates 10 and 30. This other circulation field includes channels, delimited by the plates 10 and 30, to conduct the circulation of a third operational fluid between the flow field plates 10 and 30, namely cooling fluid, and thus cool the stack 2 during its use.

[0078] In this example, the bipolar plates of the stack are provided for as consisting of two separate plates 10 and 30 placed one on top of the other. For example, each plate 10 and 30 is made of a metal sheet, which preferably forms the flow fields by stamping the sheet. Alternatively, all or part of the plates 10 or 30 can be formed from a machined plate, made of metal, graphite, or another electrically conductive material. Preferably, for each bipolar plate, the two flow field plates 10 and 30 are pre-assembled, i.e., already fixed to each other before being added to the stack 2. For example, the flow field plates 10 and 30 of the same bipolar plate are pre-assembled by being welded or brazed to each other.

[0079] Preferably, for the manufacture of the stack 1, each seal 80 is pre-assembled with one of the plates 10, 30 or 50. Preferably, before adding to the stack 2, each bipolar plate carries two seals 80, one formed on the plate 30 projecting along the direction Z2, the other formed on the plate 10 projecting in the opposite direction. Alternatively, each membrane-electrode plate 50 can be provided with two gaskets 80, one protruding along the Z2 direction to be interposed between the plate 50 and the adjacent flow field plate 10, and the other protruding in the opposite direction to be interposed between the membrane-electrode plate 50 and the adjacent flow field plate 30 on the other side of the membrane-electrode plate 50. Preferably, each gasket 80 is overmolded, cast, or printed directly onto the plate 10, 30, or 50 on which it is mounted, thus facilitating subsequent assembly. However, the use of a loose gasket is also possible.

[0080] Furthermore, it is possible to provide for the bonding of the plate 50 to one or the other of the flow field plates 10 and 30, or to both flow field plates 10 and 30, for example by simple adhesive bonding or double-sided bonding.

[0081] At their respective outer perimeter 3, each plate 10, 30, 50 and 70 has several edges, including at least one exchange edge and at least one secondary edge, and several centering notches, formed at the outer perimeter 3 of said plate. In other words, the exchange edge, the secondary edge and the centering notch belong to the perimeter 3 of the plate concerned and constitute a part of it. The exchange edge is intended to be covered by the extent of the collector 100, thus being inside the closed contour of the seal 90. The centering notch is intended to successively perform a first function, namely to ensure the guidance and centering of the plate 10, 30, 50 or 70 which carries it by cooperation with one of the rails 131, or at least to be crossed by the rail 131, when the said plate is added to the stack 2, and a second function, namely to house the portion of longitudinal seal 91 of the seal 90 once the stack 2 is completed, for sealing with the collector 100.

[0082] As shown in more detail in [Fig.4], each primary flow field plate 10 includes an exchange edge 11, two centering notches 12 and two secondary edges 13, each secondary flow field plate 30 includes an exchange edge 31, two centering notches 32 and two secondary edges 33, each membrane-electrode plate 50 includes an exchange edge 51, two centering notches 52 and two secondary edges 53 and, as shown in [Fig.2], each terminal plate 70 includes an exchange edge 71, two centering notches 72 and two secondary edges 73.

[0083] Preferably, for each plate, the centering notch is provided that the centering notch is adjacent to the exchange edge and the secondary edge, that is, at the end of the exchange edge and at the end of the secondary edge, to connect said exchange edge and said secondary edge. In other words, advantageously, each centering notch is located between one of the exchange edges and one of the secondary edges of the plate in question. Here, each plate in the stack 2 comprises only two centering notches, only one exchange edge, and only two secondary edges. Advantageously, the exchange edge is provided that is parallel to the tangential direction X2. Advantageously, the secondary edges adjacent to this exchange edge are provided that are parallel to the tangential direction X2.It is expected that the centering notches adjacent to this exchange edge are formed inward relative to the exchange edge, in the opposite direction to Y2, or opening in the direction Y2.

[0084] During manufacturing, each rail 131 extends parallel to the Z2 direction. Each centering notch 12, 32, 52, and 72 corresponds with the rail 131 along the X2 direction and straddles or wraps around the rail 131 along the Y2 direction, such that the rail 131 is at least partially received in each of the notches 12, 32, 52, and 72, as shown in Figures 5 and 7-9. In order to cooperate by sliding along the Z2 direction with the rail 131 during manufacturing, at least some of the centering notches 12, 32, 52, and 72—namely, centering notches 32, 52, and 71—are "centering notches with contact," which have a shape complementary to that of rail 131, to conform to the shape of rail 131, or at least to be in contact with rail 131 to center the plate in question along the X2 and / or Y2 directions relative to rail 131. Preferably, other centering notches, namely notches 12, are "non-contact centering notches" which allow the passage of rail 131, which are only traversed by rail 131 during manufacturing, and which do not need to be complementary to rail 131, but only to be sufficiently recessed and / or wide enough to be traversed by rail 131, while remaining at a distance from rail 131. Centering notches 12, 32, 52, and 72 are also shaped to allow the withdrawal of rail 131, moving the rail away from stack 2 along the Y2 direction, once Stack 2 complete.

[0085] In the present example, as seen in Figures 5 and 7-9, the rail 131 has a cylindrical shape with a circular base, centered on an axis parallel to the direction Z2. Preferably, as clearly seen in Figures 5 and 6, for each plate, the centering notch 12, 32, 52, or 72 has a profile in the shape of a circular arc, projected onto a projection plane P2 that is orthogonal to the stacking direction Z2. The plane P2 is parallel to the plane in which Figures 5 and 6 are drawn. By "profile," we mean the edge of the notch. In other words, it is preferred that the centering notches be rounded, which allows the notches to serve both for centering the plates during the manufacture of pile 1 and to receive the longitudinal joint portion 91 of the joint 90. However, other profiles could be provided, for example in "U", in "V",....If rail 131 has a different shape than that shown here, a corresponding shape can be provided for the centering notches. In the example, the edge profile of the contacting centering notch is the same as the cross-sectional profile of rail 131, so as to allow contact along a segment of this notch edge profile of a certain length. However, it could be provided that the edge profile of the contacting centering notch and the cross-sectional profile of rail 131 are designed to ensure only point contacts, preferably with enough point contacts so that the contact between the edge of the contacting centering notch and rail 131 precisely determines the relative position of the notch with respect to the rail in both transverse directions X2 and Y2.

[0086] As can be seen in [Fig. 4], each peripheral joint 80 preferably comprises a portion of a heat exchange edge 81, which is interposed between the heat exchange edge 11 or 31 of the adjacent plate 10 or 30, and the heat exchange edge 51 of the adjacent plate 50, along the direction Z2. The portion of the heat exchange edge 81 extends parallel to and along these heat exchange edges 11, 31, 51 of the adjacent plates. Each peripheral joint 80 preferably comprises a portion of a secondary edge 83, which is interposed, on the one hand, between the secondary edge 13 or 33 of the adjacent flow field plate 10 or 30, and, on the other hand, the secondary edge 53 of the adjacent plate 50, along the direction Z2. The portion of the secondary edge 83 extends parallel to and along these secondary edges. Each peripheral joint 80 preferably includes a recessed portion 82, which is interposed between the notch 12 or 32 of the adjacent plate 10 or 30, and the notch 52 of the adjacent plate 50, along the direction Z2. The recessed portion 82 extends along these centering notches and preferably has a profile similar to that of these centering notches, in particular to allow the rail 131 to pass through it during manufacturing.Preferably, for each joint 80, the recessed portion 82 is adjacent to the exchange edge 81 and the secondary edge 83; that is, it is at the end of portion 81 and at the end of portion 83, to connect portions 81 and 83. In other words, advantageously, each recessed portion 82 is located between portions 81 and 83, respectively exchange edge 81 and secondary edge 83. Here, each joint 80 comprises only two recessed portions 82, only one exchange edge portion 81, and only two secondary edge portions 83, corresponding to the number of exchange edges, secondary edges, and centering notches on each plate. Advantageously, the exchange edge portion 81 is parallel to the tangential direction X2. It is advantageously expected that the portions of secondary edge 83 adjacent to this portion of exchange edge 81 are parallel to the tangential direction X2.It is anticipated that the recessed portions 82 adjacent to this portion of the interchange edge 81 are formed in a recess relative to this portion of the interchange edge 81, in the opposite direction to Y2, or opening along the direction Y2.

[0087] In the example, the recessed portion 82 has a profile in the shape of an arc of a circle, in projection into the projection plane P2, or, more generally, a profile of the same shape or corresponding to that of the adjacent centering notches 12, 52 or 72 belonging respectively to the plates 10, 50 or 70, as described above.

[0088] The successive heat exchange edges 11, 31, 51, and 71 of the plates 10, 30, 50, or 70 are superimposed along the Z2 direction. In this particular case, the term "superimposed" has a special meaning, in that it does not preclude the possibility that some heat exchange edges may be recessed and others projecting along the Y2 direction, as described below by way of preference. However, "superimposed" indicates that, overall, the heat exchange edges extend along the same plane perpendicular to the Y2 direction. Except for this particular case and a few others described below, the term "superimposed" is used with its usual meaning.

[0089] The exchange edges together form the exchange face 5, or one of the exchange faces. The exchange face 5 is therefore a face that is not necessarily flat, which may therefore include grooves corresponding to the recessed heat exchange edges. If seals 80 are provided, the portion of the heat exchange edge 81 also belongs to this heat exchange face 5. Preferably, the heat exchange edges 11, 31, 51, and 71, which overlap along the Z2 direction, are parallel to each other. Preferably, the heat exchange edges 11 of the primary flow plates 10, which overlap along the Z2 direction, are arranged in the same plane parallel to the Z2 direction and are arranged in the same position along the tangential X2 direction, or even, are of the same length along the X2 direction. Preferably, the heat exchange edges 31 of the secondary flow plates 30, which overlap along the Z2 direction, are arranged in the same plane parallel to the Z2 direction and are arranged in the same position along the tangential X2 direction, or even, are of the same length along the X2 direction.Preferably, the exchange edges 51 of the membrane-electrode plates 50, which are superimposed along the direction Z2, are arranged in the same plane parallel to the direction Z2 and are arranged in the same position along the tangential direction X2, or even, are of the same length along the direction X2. Preferably, the exchange edges 71 of the terminal plates 70, which are superimposed along the direction Z2, are arranged in the same plane parallel to the direction Z2 and are arranged in the same position along the tangential direction X2, or even, are of the same length along the direction X2.

[0090] The successive secondary edges 13, 33, 53, and 73 of the plates are superimposed along the Z2 direction. In this case, "superimposed" has a particular meaning, in that this term does not preclude the possibility that some secondary edges may be recessed and others project along the Y2 direction, as described below. However, "superimposed" means that, overall, the secondary edges extend along the same plane perpendicular to the Y2 direction. The secondary edges together form one of the secondary faces 7. If joints 80 are provided, the portion of the secondary edge 83 also belongs to this secondary face. Preferably, the secondary edges 13, 33, 53, and 73 superimposed along the Z2 direction are parallel to each other.Preferably, the secondary edges 13 of the primary flow plates 10, which are superimposed along the Z2 direction, are arranged in the same plane parallel to the Z2 direction and are arranged in the same position along the tangential X2 direction, or even, are of the same length along the X2 direction. Preferably, the secondary edges 33 of the secondary flow plates 30, superimposed along the Z2 direction, are arranged in the same plane parallel to the Z2 direction and are arranged in the same position along the tangential X2 direction, or even, are of the same length along the X2 direction. Preferably, the secondary edges 53 of the membrane-electrode plates 50, superimposed along the Z2 direction, are arranged in the same plane parallel to the Z2 direction and are arranged in the . the same position along the tangential direction X2, or even, are of the same length along the direction X2. Preferably, the secondary edges 73 of the terminal plates 70, superimposed along the direction Z2, are arranged in the same plane parallel to the direction Z2 and are arranged in the same position along the tangential direction X2, or even, are of the same length along the direction X2.

[0091] The successive centering notches 12, 32, 52, and 72 of the plates are superimposed along the Z2 direction. Here again, "superimposed" has a particular meaning, in that this term does not preclude the possibility that some centering notches may be recessed and others protrude along the Y2 direction, as described below by way of preference. "Superimposed" nevertheless indicates that, overall, the centering notches are aligned along the same axis parallel to the Z2 axis. The centering notches together form one of the centering grooves 6. If the seals 80 are provided, the recessed portion 82 also belongs to this centering groove. Preferably, the notches 12 of the primary flow plates, superimposed along the Z2 direction, are identical and are arranged in the same position along the X2 and Y2 directions.Preferably, the notches 32 of the secondary flow plates 30, superimposed along the Z2 direction, are identical and arranged in the same position along the X2 and Y2 directions. Preferably, the notches 52 of the membrane-electrode plates 50, superimposed along the Z2 direction, are identical and arranged in the same position along the X2 and Y2 directions. Preferably, the notches 72 of the end plates 70, superimposed along the Z2 direction, are identical and arranged in the same position along the X2 and Y2 directions.

[0092] Advantageously, at least some of the flow plates 10 and 30 form exchange ports 19. Each port 19 opens onto one of the exchange edges 11 and / or 31 along the normal direction Y2, that is, the ports 19 open onto the surface of the exchange face 5 formed by these exchange edges 11 and 31. The ports 19 thus open into the inside of the manifold 100, in particular into the inside of the connector 101, and are covered by the manifold 100, in particular by the connector 101, and framed by the seal 90. Preferably, each edge 11 and / or 31 comprises a row of ports 19, said row being parallel to the direction X2, so that the assembly formed by the stacking of the edges 11, 31 presents a grid pattern. 19 orifices which extend along the X2 and Z2 directions over all or most of the exchange face 5.

[0093] The exchange ports 19 are provided to establish fluidic communication between the external manifold 100 and the reactive operating fluid circulation fields of the plates 10, or with the reactive operating fluid circulation fields of the plates 30, or with the cooling operating fluid circulation fields formed between adjacent plates 10 and 30. To this end, each exchange port 19 leads to one or more of the channels of the relevant circulation field. Advantageously, no exchange orifice 19 is provided on the stack outside the exchange face(s) 5. The exchange of the operating fluid between the external manifold 100 and the stack 2 is therefore carried out via the exchange orifices 19 located on the face 5 to which the manifold 100 is connected. In this example, the exchange orifices 19 are formed exclusively by the plates 10, on their respective exchange edge 11. For a given exchange face 5, corresponding to a given external manifold 100, all the orifices 19 opening into this exchange face communicate exclusively with the circulation fields of the same operating fluid for all the electrochemical cells covered by this exchange face 5.

[0094] Preferably, as seen in figures 2 and 3, the transverse grooves 8 are each formed on the respective exchange edge 71 of one of the terminal plates 70. Therefore, for each of these terminal plates 70, the transverse groove 8 connects the centering notches 72 of the terminal plate 70 considered, so as to open into each of these centering notches 72 of the terminal plate 70 considered, thus connecting the centering grooves 6.

[0095] Preferably, for at least one of the plates of the stack 2, and preferably for all the plates of the stack 2, the exchange edge 11, 31, 51 or 71 of the plate concerned is slightly projecting outwards from the stack 2, i.e. in the Y2 direction, relative to the adjacent secondary edges 13, 33, 53 or 73. Thus, in [Fig.5], it has been illustrated that the exchange edge 11, 31 of each flow field plate 10, 30 is projecting outwards from the stack 2, i.e. in the Y2 direction, relative to the adjacent secondary edge 13, 33 of the same flow field plate 10, 30, by an amount, called the exchange edge offset "dl-3", which is preferably between 0.05 millimeters and 3 millimeters, preferably between 0.2 millimeters and 1 millimeter.As a result, when the longitudinal joint portions 91 are formed and / or when they are compressed by the collector 100, there is less chance that they will overflow on the side of the exchange face 5, and that they will accidentally block the exchange ports 19. Alternatively, however, it can be provided that the exchange edge is aligned with the secondary edge, that is to say, extends along the same axis along the direction XL.

[0096] Preferably, for at least one of the membrane electrode plates 50, and preferably for all the membrane-electrode plates 50 of the stack 2, the exchange edges 51 of the membrane-electrode plate 50 project outwards from the stack 2, i.e., along the Y2 direction, relative to the exchange edges 11 and 31 of the adjacent flow field plates 10 and 30. Preferably, for at least one of the membrane electrode plates 50, and preferably, For all the membrane-electrode plates 50 of the stack 2, the secondary edges 53 of the membrane-electrode plate 50 project outwards from the stack 2, i.e., along the Y2 direction, relative to the secondary edges 13 and 33 of the adjacent flow field plates 10 and 30. These arrangements advantageously reduce the risk of short circuits between the edges 11 and 31 and between the edges 13 and 33 of these plates 10 and 30, by improving their separation by the electrically insulating edges 51 and 53. Thus, in [Fig.5], it has been illustrated that the exchange edge 51 of each membrane-electrode plate 50 protrudes outwards from the stack 2, i.e. in the direction Y2, relative to the exchange edges 11 and 31 of the adjacent flow field plates 10 and 30, by an amount, called the membrane-electrode plate offset "d50", which is preferably between 0.1 millimeter and 2 millimeters, preferably between 0.2 millimeter and 1 millimeter. Similarly, for all membrane-electrode plates 50 of the stack 2, the secondary edges 53 of the membrane-electrode plate 50 protrude outwards from the stack 2, i.e. in the direction Y2, relative to the secondary edges 13 and 33 of the adjacent flow field plates 10 and 30 by the same value of membrane-electrode plate offset "d50", preferably between 0.1 millimeter and 2 millimeters, preferably between 0.2 millimeter and 1 millimeter.

[0097] Preferably, for at least one of the bipolar plates, and preferably for all of them, the exchange edge 11 of the primary flow field plate 10 and the exchange edge 31 of the secondary flow field plate 30 are mutually flush, i.e., are at the same level along the Y2 direction. Preferably, likewise, the secondary edges 13 of the primary flow field plate 10 and the secondary edges 33 of the secondary flow field plate 30 are mutually flush, i.e., are at the same level along the Y2 direction.

[0098] Preferably, for at least one of the bipolar plates, and preferably for all of them, the centering notch 12 of the primary flow field plate 10 is recessed towards the inside of the stack 2, that is, in the opposite direction to Y2, relative to the centering notch 32 of the secondary flow field plate 30. The centering notch 32 of the secondary flow field plate 30 may also be smaller, in the X2 and Y2 directions, than the centering notch 12 of the primary flow field plate 10. Thus, during the manufacture of the stack 1, for each bipolar plate, it is the centering notch 32 of the secondary flow field plate 30 that bears transversely against the centering rail 131 to ensure positioning transverse to the bipolar plate, which can therefore be described as a centering notch with contact, whereas The centering notch 12 remains separate from the centering rail 131, being traversed by the rail 131 along the Z2 direction, and can therefore be described as a centering notch with contact. This is particularly possible when the bipolar plate is made up of the pre-assembled plates 10 and 30 added to the stack together, or when the stack is made by stacking pre-assembled electrochemical cells. Thus, in [Fig.5], it has been illustrated that, for at least one of the bipolar plates, and preferably for all, the centering notch 12 of the primary flow field plate 10 is set back towards the inside of the stack 2, that is, in the opposite direction to the Y2 direction, relative to the centering notch 32 of the secondary flow field plate 30 by an amount, called notch offset "dl2-32", which is preferably between 0.1 millimeter and 1 millimeter, preferably between 0.2 millimeter and 0.6 millimeter.Of course, this notch offset between the centering notch 12 of the primary flow field plate 10 and the centering notch 32 of the secondary flow field plate 30 is independent of whether, for example, the primary flow field plate 10 is a cathodic or anodic plate, the secondary flow field plate 30 then being respectively an anodic or cathodic plate.

[0099] Preferably, the centering notch 52 of at least one of the membrane-electrode plates 50, or of all the membrane-electrode plates 50, is flush with the centering notch 32 of the adjacent secondary flow field plate 30. The centering notch 52 of at least one of the membrane-electrode plates 50, or of all the membrane-electrode plates 50, may also, in addition, be the same size, along the X2 and Y2 directions, as the centering notch 32 of the adjacent secondary flow field plate 30. Thus, during the manufacture of stack 2, the centering notch 52 rests on the centering rail 131 to ensure the transverse positioning of the plate 50, when the plate 50 is added to stack 2, and can therefore also be described as a centering notch with contact.

[0100] Alternatively, the centering notch 52 of at least one, or all, of the membrane-electrode plates 50 may be slightly recessed towards the inside of the stack 2 relative to the centering notch 32 of the adjacent secondary flow field plate 30, and may therefore in this case be described as a non-contact centering notch. Preferably, the centering notch 52 then protrudes outwards from the stack 2 relative to the centering notch 12 of the adjacent primary flow field plate 10. In this case, it can also be assumed that the centering notch 52 has an intermediate size, along the X2 and Y2 directions, between those of notches 12 and 32. In this case, to ensure the centering of plate 50 during stacking, for example, that the membrane-electrode plate 50 is pre-assembled with another plate that has a centering notch with contact, here for example the adjacent secondary flow field plate 30. For aligning the membrane-electrode plate 50 with this other plate for the purpose of its pre-assembly, or for stacking the membrane-electrode plate 50 without pre-assembly, the centering of the membrane-electrode plate 50 can be ensured, for example, by optical alignment or by pre-alignment geometric shapes between the two adjacent plates.

[0101] Preferably, as shown in [Fig. 4], each flow field plate 10 occupies a thickness E10 within the stack 2, the thickness E10 being measured parallel to the stacking direction Z2. E10 is the thickness occupied at the perimeter 3 of the flow field plate 10. Preferably, each flow field plate 30 occupies a thickness E30 within the stack 2, the thickness E30 being measured parallel to the stacking direction Z2. E30 is the thickness occupied at the perimeter 3 of the flow field plate 30. Preferably, each membrane-electrode plate 50 occupies a thickness E50 within the stack 2, the thickness E50 being measured parallel to the stacking direction Z2. E50 is the thickness occupied at the perimeter 3 of the membrane-electrode plate 50.Preferably, the thicknesses E10 and E30 are greater than the thickness E50, so that the plates E10 and E30 can provide sufficient internal volume for the flow field channels in the direction of the stacking direction Z2. Furthermore, it is advantageous for the thickness E10 to be greater than the thickness E30. For example, the thickness E10 is at least 1.5 times greater than the thickness E30, or even twice as great. This difference between the thicknesses E10 and E30, combined with the positioning and / or relative size of the notches 12 and 32 described above, reduces the risk of short circuits between flow field plates 10 and 30 adjacent to the same membrane-electrode plate 50.Indeed, within the groove 6, the distance to be travelled for the formation of an electric arc linking the notch 12 to the notch 32 located beyond the membrane-electrode plate 50, is particularly high, thanks to the recess of the notch 12 and the thickness of the plate 10, in addition to the presence of the insulating and protruding notch 52.

[0102] Preferably, for at least one of the peripheral seals 80, if not for all of the peripheral seals 80, the portion of the exchange edge 81 is flush along the direction Y2 with the exchange edge 11 or 31 of the plate 10 or 30 against which the seal 80 is formed. Alternatively, the portion of the exchange edge 81 could be slightly recessed in the opposite direction to Y2, or slightly projected along the direction Y2, relative to the exchange edge 11 or 31 of the plate 10 or 30 against which the seal 80 is formed. Preferably, for at least For one of the seals 80, if not all of the seals 80, the portion of the exchange edge 81 is recessed, in the opposite direction to Y2, relative to the exchange edge 51 of the plate 50 against which the seal 80 is formed. In other words, the edge 51 advantageously projects in the direction Y2 relative to the portion 81.

[0103] Preferably, for at least one of the peripheral seals 80, if not for all of the peripheral seals 80, the secondary edge portion 83 is flush along the Y2 direction with the secondary edge 13 or 33 of the plate 10 or 30 against which the seal 80 is formed. Alternatively, the secondary edge portion 83 could be slightly recessed in the opposite direction to Y2, or slightly projecting along the Y2 direction, relative to the secondary edge 13 or 33 of the plate 10 or 30 against which the seal 80 is formed. Preferably, for at least one of the seals 80, if not for all of the seals 80, the secondary edge portion 83 is recessed in the opposite direction to Y2 relative to the secondary edge 53 of the plate 50 against which the seal 80 is formed. In other words, edge 53 is advantageously projecting along the Y2 direction relative to portion 83.

[0104] Preferably, for at least one of the peripheral seals 80 interposed between a plate 10 and a plate 50, or for all such seals 80 interposed between a plate 10 and a plate 50, the recessed portion 82 is flush along the Y2 direction with the notch 12 of this plate 10 against which the seal 80 is formed. Preferably, this same recessed portion 82 is set back along the Y2 direction with respect to the notch 52 of the plate 50 against which the seal 80 is formed. This may imply that the size of the recessed portion 82 is larger than the size of the notch 52. During manufacturing, the recessed portion 82 can thus be traversed by the rail 131 without touching it.

[0105] Preferably, for at least one of the peripheral seals 80 interposed between a plate 30 and a plate 50, or otherwise for all such peripheral seals 80 interposed between a plate 30 and a plate 50, the recessed portion 82 is set back in the direction Y2, relative to the notches 32 and 52 of the plates 30 and 50 between which the peripheral seal 80 is interposed. This may imply that the size of the recessed portion 82 is larger than the size of the notches 32 and 52. During manufacturing, the recessed portion 82 of the peripheral seal 80 can thus be traversed by the rail 131 without touching it.

[0106] Preferably, for at least one of the end plates 70, and preferably for both plates 70, the exchange edge 71, the secondary edge 73, and the notch 72 are arranged in the same way as the exchange edge 31, the secondary edge 33, and the notch 32 of the plate 30. In other words, except at the groove 8, the exchange edge 71, the secondary edge 73, and the notch 72 have the same shape and arrangement as those of the plate 30. Preferably, a thickness of the plate 70, measured at its perimeter 3 parallel to thicknesses E10 and E30, is greater than thicknesses E10 and E30.

[0107] As shown in Figures 2 and 6, the longitudinal portion 91 of the seal 90, in the opposite direction to Y2, conforms to and fills the shape of the various notches 12, 32, 52 and 72 and the recessed portions 82. In particular, the notches 32 and 52, which protrude from the others, are advantageously encapsulated by the portion 91 of the seal 90. In other words, the seal 90 is interposed along the Z2 direction between the respective perimeter 3 of the successive plates 30 and 50, at the level of the notches 32 and 52, being received in the notches 12 and the recessed portions 82. Thanks to these arrangements, not only is optimal sealing of the fluid connection between the manifold 100 and the face 5 ensured, but the risk of electric arcing within the groove 6 is also reduced.

[0108] In addition, the joint 90 protrudes, along the direction Y2, beyond the exchange edges 11, 31, 51 and 71. Preferably, the joint 90 thus protrudes over its entire perimeter, that is to say for the portions of joint 91 and 92.

[0109] To manufacture the fuel cell 1, a process as defined below, and as illustrated in figures 7 to 9, can be implemented.

[0110] As shown in [Fig. 7], the support plate 111 is preferably positioned in a horizontal plane so that the direction Z2 is vertical and upwards. While the plates 10, 30, 50, and 70 and the joints 80 are not yet stacked and the joint 90 is not yet formed, the peripheral centering template 130, comprising the rails 131, is temporarily installed. Here, only two rails 131 are provided for the template 130, but a different number can be provided by providing a corresponding number of centering grooves 6 on the plates 10, 30, 50, and 70. The template 130 also includes a mounting base 132, to which the rails 131 are fixedly attached.

[0111] The centering template 130 is attached to the periphery of the stack 2, that is to say on the outside of the stack 2, against the side 4 of the stack 2 bearing the grooves 6. To be fixed to the plate 111, the template 130 is attached by being moved until it comes into contact with the plate 111 parallel to the direction Y2, or at least with a movement having a component along the direction Y2.

[0112] To be attached to the plate 111, the base 132 is advantageously provided to be pressed against the mounting edge 115 of the plate 111, that is to say, advantageously the same mounting edge 115 that will later be used to attach the collector 100. Preferably, the base 132 is attached to the mounting edge 115 by screwing. Tapped holes provided in the edge 115 can be used for screwing the template 130 and, later, for screwing the collector 100.

[0113] When the 130 gauge is installed, the 131 rails protrude in the Z2 direction at starting from base 132, being distributed in a plane perpendicular to the direction X2.

[0114] At this stage, additional peripheral centering jigs can be provided, positioned opposite other sides 4 of the stack 2, if these other sides 4 have corresponding centering grooves. Finally, internal centering means within the stack 2 can be provided, such as rods parallel to the direction Z2 and passing through the stack 2 internally, from plate 111.

[0115] Once the template(s) 130 are installed, the plates 10, 30, 50, and 70 and the joints 80 are stacked to form stack 2, while the joint 90 is not yet formed. To perform the stacking, each plate is slid parallel to the direction Z2 along the rails 131, with the corresponding centering notch on each plate receiving the rail 131. In other words, the rail 131 serves to guide the plate via the corresponding centering notch. As mentioned above, preferably, some plates are stacked individually, for example, plates 50 and 70, while other plates, namely, for example, plates 10 and 30, are pre-assembled in pairs before being stacked. Preferably, each joint 80 is pre-assembled with one of the plates, preferably one of the plates 10 and 30, before being added to stack 2.In practice, except possibly at the ends of stack 2, a complete bipolar plate is added to stack 2, including two adjacent pre-assembled plates 10 and 30 and two joints 80 formed respectively on plates 10 and 30.

[0116] For each plate, or each pre-assembled assembly comprising several plates, at least one of the centering notches cooperates mechanically with the rail 131 to guide the sliding along Z2 and center this pre-assembled assembly or plate along the X2 and Y2 directions, while the other centering notches, set back from the rail 131 along the Y2 direction, are only crossed by the rail 131 along the Z2 direction.In this example, only the notches 32, 52, and 72, respectively of the secondary flow plates 30, the membrane-electrode plates 50, and the end plates, are centering notches with contact that cooperate mechanically with the rail 131, while the notches 12 and the recessed portions 82, respectively of the primary flow field plates 10 and the peripheral seals 80, which are further back, are at a distance from the rail 131, being only traversed by the rail 131 in the Z2 direction, and are therefore centering notches without contact. The cooperation of the rails 131 with the centering notches ensures that, once the stack 2 is complete, each plate of the stack 2 is correctly positioned against the adjacent plate, particularly in the X2 and Y2 directions.

[0117] To perform the stacking, as shown in [Fig. 7], one advantageously begins by stacking the end plate 70 against the support plate 111, by sliding the end plate 70 along the rails 131 by means of the notches 72. A current collector and a planar sealing gasket, not shown, are then advantageously stacked.

[0118] A flow field plate 30 is then stacked, guiding the plate 30 along the direction Z2 by cooperation of the rails 131 with the notches 32, until the plate 50 comes to rest against the elements already assembled in the opposite direction of the Z2 direction.

[0119] One of the plates 50 is then stacked, guiding the plate 50 along the Z2 direction by the cooperation of the rails 131 with the notches 52, until the plate 50 comes to rest against the already assembled flow field plate 30. A pre-assembled bipolar assembly is then stacked, comprising a plate 10, carrying a seal 80 facing the already stacked plate 50, a plate 30 fixed to the plate 10 along the Z2 direction, and a second seal 80 formed on the plate 30 along the Z2 direction. This pre-assembled assembly is guided by the rails 131 by cooperation of said rails with the notches 32. Another plate 50 is then stacked, and so on, alternating between a pre-assembled bipolar assembly and a plate 50. Once the last plate 50 is stacked, a final flow field plate 10 is added, on which another current collector and possible sealing gasket are stacked.The second terminal plate 70 is then stacked.

[0120] Stack 2 is then completed, and is kept centered using the rails 131, which are still in place.

[0121] Once the stack 2 is complete and while the joint 90 is still not in place, the tie rods 113 are installed on the support plate 111. Then, the springs 114 and the support plate 112 are installed, so that the springs 114 are interposed in the direction Z2 between the support plate 112 and the plate 70 at the top of the stack 2. The installation of the support plate 112 preferably includes threading the support plate 112 onto the tie rods 113.

[0122] Preferably, the support plate 112 carries a fixing base 134, which is fixed to the fixing edge 116 of the support plate 112, preferably by screwing, in a similar manner to the fixing base 132, fixed to the fixing edge 115 of the support plate 111. The base 134, which belongs to the template 130 and is initially separate from the template 130, is configured to be threaded onto the rails 131, in order to be guided in sliding by the rails along the direction Z2. To install the support plate 112, the plate is advantageously slid onto the tie rods 113, preferably with the base 134 slid onto the rails 131, along the direction Z2, with the springs 114 interposed between the plate 112 and the plate 70 at the top of the stack 2

[0123] Once the stack 2 is arranged between the two support plates 111 and 112, and While the 130 gauge, in particular the 131 rails, are still in place, stack 2 is put into compression using the 113 tie rods, for example by tightening nuts at the ends of the 113 tie rods to bring the support plates 111 and 112 closer together along the Z2 direction. A press assembly is also possible, followed by tightening the tie rod nuts to the specified torque.

[0124] Once the stack 2 is compressed between the plates 111 and 112, and before forming the joint 90, the rails 131 are removed, for example, by removing the entire template 130. To do this, the bases 132 and 134 are advantageously detached from the plates 111 and 112 to separate the rails 131 from the plates 111 and 112. Then, the template 130 is moved away from the stack 2 transversely with respect to the Z2 direction, that is, in a movement that includes a component along Y2 with respect to the stack 2. In particular, the rail 131 is extracted from the centering groove 6 by being moved transversely with respect to the Z2 direction, specifically along the Y2 direction with respect to the stack 2. The removal of the rails 131 is therefore particularly easy. This leads to the configuration of [Fig.3].

[0125] Once the rails 131 have been removed, the collector joint 90 is put in place, in particular with portions 91 in the grooves 6 and portions 92 in the grooves 8. Preferably, the joint 90 is formed in situ, by pouring, injecting or overmolding the joint 90 in a liquid or paste-like state into the grooves 6 and 8, and then hardening the joint 90. To form the joint 90 while it is in a liquid or paste-like state, it is preferable that the stack 1 be oriented so that the direction Y2 is directed upwards, so that gravity helps to ensure that the liquid or paste-like material is received in the grooves 6 and 8 without overflowing and conforming to the inner contours of the grooves 6 and 8.

[0126] To form the seal 90, preferably as shown in [Fig. 6], a first bead 95 of a first material in a liquid or paste-like state is first applied in the grooves 6 and 8, over the entire perimeter of the future seal 90. The first material is advantageously silicone-based, or another suitable elastomer, which is non-crosslinked during application so as to be in a liquid or paste-like state and thus conform to the bottom of the grooves 6 and 8, in particular by encapsulating the protruding notches 32 and 52. A low-viscosity material is advantageously chosen to give it a self-leveling and / or filling characteristic. This ensures that the material conforms to the bottom of the grooves 6 and 8, particularly that of groove 6, which is irregular because some centering notches are protruding and others are recessed.Despite its low viscosity, the material can be applied very precisely, because it is prevented from spreading along the X2 direction by groove 6 and along the Z2 direction by groove 8.

[0127] Once the first bead 95 is applied, it is cured in situ. In the case of a silicone, curing can be achieved, for example, by temperature curing ambient temperature of the silicone. The first bead 95 then forms a base belonging to the future joint 90, which fills and fits the grooves 6 and 8 all around the perimeter of the joint 90.

[0128] Once the first bead 95 has been applied, a second bead 96 of a second material in a liquid or paste state is applied over the first bead 95. The second bead 96 may be applied while the first bead 95 is only partially hardened, in order to ensure good cohesion between the beads 95 and 96. The second bead 96 covers the first bead over the entire periphery of the joint 90, formed by the beads 95 and 96. The second bead 96 is formed so as to protrude from the grooves 6 and 8, over the entire perimeter of the joint 90.

[0129] The second bead 96 is advantageously made of a second material, different from the first at least in its viscosity, the viscosity being compared when the materials are in their uncured state. Advantageously, the second material for forming the second bead 96, in its liquid or paste state, is chosen to be more viscous than the first material for forming the first bead 95 when the first material is itself in its liquid or paste state. This advantageously allows the second bead 96, applied in its liquid or paste state, to retain a raised shape over the first bead 95, even when the second material has not yet cured. This advantageously allows the second bead 96, and even the joint 90 in general, to be formed without a mold. Preferably, the second material is also silicone-based, or of another suitable elastomer.Once the second bead 96 has been applied, it is hardened in situ, for example by cross-linking the silicone at room temperature. This results in the configuration shown in [Fig.2].

[0130] Although the process for forming the 90 joint described above is preferred, alternatively, the 90 joint can be formed in a single pour of material, or the 90 joint can be formed according to other suitable processes.

[0131] Once the seal 90 is formed, the fluidic connection of the outer manifold 100 with the exchange face 5 is made. To do this, the manifold 100, in particular the connector 101, is brought against the exchange face, by bringing the connector 101 towards the stack parallel to the direction Y2. At least, the approach movement of the connector 101 has a component along the direction Y2. The connector 101 is aligned with the seal 90, so that the connector 101 is in sealing contact over the entire perimeter of the seal 90. In particular, the manifold 100 rests in sealing contact with the seal 90 via the cord 96. Finally, the outer manifold 100 is fixed using the fixing system 102, in particular by screwing the base 103 to the fixing edge 115 and fixing the base 104 to the fixing edge 116. This results in the configuration of [Fig.1].

[0132] Any feature described above for one of the embodiments or variants can be implemented for the other embodiments or variants described above, insofar as technically possible.

Claims

1. Demands Fuel cell (1), comprising: • a stack (2), comprising plates (10, 30, 50, 70), the plates (10, 30, 50, 70) of the stack (2) comprising flow field plates (10, 30) and membrane-electrode plates (50) and being stacked along a stacking direction (Z2) to constitute electrochemical cells, each plate (10, 30, 50, 70) being oriented perpendicular to the stacking direction (Z2) by being arranged flat against the adjacent plate (10, 30, 50, 70), each plate (10, 30, 50, 70) comprising a respective exchange edge (11, 31, 51, 71), the exchange edges (11, 31, 51, 71) being parallel to each other and together forming an exchange face (5) belonging to the stack (2), the exchange face (5) extending parallel to the stacking direction (Z2); • an external collector (100), which is fluidically connected to the stack (2) by being brought against the stack (2) so as to cover the exchange face (5), for an exchange of an operational fluid between the external collector (100) and the stack (2) via the exchange face (5); • a manifold seal (90), which frames the exchange face (5) and is interposed between the stack (2) and the outer manifold (100), to ensure a tight seal of the fluid connection between the outer manifold (100) and the stack (2); and • a fastening system (102), through which the collector (100) is fixed; in which: • Each plate (10, 30, 50, 70) includes a respective centering notch (12, 32, 52, 72) adjacent to the exchange edge (11, 31, 51, 71), the centering notches (12, 32, 52, 72) together forming a centering groove (6) belonging to the stack (2), the centering groove (6) bordering the exchange face (5) and extending parallel to the stacking direction (Z2); and • the manifold joint (90) includes a longitudinal joint portion (91), which is parallel to the stacking direction (Z2), which is formed in the centering groove (6), so that the longitudinal joint portion (91) is interposed between the stack (2) and the outer manifold (100) to ensure the sealing of the fluidic connection between the outer manifold (100) and the stack (2).

2. Fuel cell (1) according to claim 1, wherein at least one of the flow field plates (10, 30) forms exchange ports (19), formed at the exchange edge (11, 31) of the flow field plate (10, 30), to open onto the surface of the exchange face (5) and be covered by the outer collector (100), the operational fluid exchange between the outer collector (100) and the stack (2) being carried out via the exchange ports (19).

3. Fuel cell (1) according to any one of the preceding claims, wherein the plates (10, 30, 50, 70) of the stack (2) comprise a respective secondary edge (13, 33, 53, 73), parallel to the exchange edge (11, 31, 51, 71) and being connected to the exchange edge (11,31, 51,71) by the centering notch (12, 32, 52, 72).

4. Fuel cell (1) according to claim 3, wherein, for at least one of the plates (10, 30, 50, 70) of the stack (2), the exchange edge (11, 31, 51, 71) is projecting outwards from the stack (2) relative to the secondary edge (13, 33, 53, 73).

5. Fuel cell (1) according to any one of claims 3 or 4, wherein, for at least one of the membrane-electrode plates (50), the secondary edge (53) of the membrane-electrode plate (50) is projecting outwards from the stack (2), relative to the secondary edge (13, 33) of the adjacent flow field plates (10, 30).

6. Fuel cell (1) according to any one of the preceding claims, wherein: • the flow field plates (10, 30) comprise primary flow field plates (10) and secondary flow field plates (30); • at least one of the primary flow field plates (10) is adjacent to one of the secondary flow field plates (30) to form, with said secondary flow field plate (30), a bipolar plate; and • for at least one of the bipolar plates: • the exchange edge (11) of the primary flow field plate (10) and the exchange edge (31) of the secondary flow field plate (30) are mutually flush, and • the centering notch (12) of the primary flow field plate (10) is recessed into the stack (2) relative to the centering notch (32) of the secondary flow field plate (30).

7. Fuel cell (1) according to claim 6, wherein the centering notch (52) of at least one of the membrane-electrode plates (50) is flush or recessed inwards from the stack (2), relative to the centering notch (32) of the adjacent secondary flow field plate (30), and protrudes outwards from the stack (2), relative to the centering notch (12) of the adjacent primary flow field plate (10).

8. Fuel cell (1) according to any one of the preceding claims, wherein, for at least one of the membrane-electrode plates (50), the exchange edge (51) of the membrane-electrode plate (50) is projecting outwards from the stack (2), relative to the exchange edge (11, 31) of the adjacent flow field plates (10, 30).

9. Fuel cell (1) according to any one of the preceding claims, wherein the stack (2) further comprises peripheral seals (80), each peripheral seal (80) being interposed between one of the flow field plates (10, 30) and one of the membrane-electrode plates (50) along the stacking direction (Z2), each peripheral seal (80) comprising: • a portion of the exchange edge (81), which is interposed between the exchange edge (11, 31) of the flow field plate (10, 30) and the exchange edge (51) of the membrane-electrode plate electrode (50) along the stacking direction (Z2), being flush with the exchange edge (11, 31) of said flow field plate (10, 30) or set back towards the inside of the stack (2) relative to the exchange edge (11, 31) of said flow field plate (10, 30); and • a hollow portion (82), which is interposed between the centering notch (12, 32) of the flow field plate (10, 30) and the centering notch (52) of the membrane-electrode plate (50) along the stacking direction (Z2), the hollow portion (82) being recessed towards the inside of the stack (2) relative to the centering notch (52) of the membrane-electrode plate (50) and being flush or recessed towards the inside of the stack (2) relative to the centering notch (12, 32) of the flow field plate (10, 30).

10. Fuel cell (1) according to any one of the preceding claims, wherein, for at least one of the plates (10, 30, 50, 70) of the stack (2), the centering notch (12, 32, 52, 72) has a profile in the shape of an arc of a circle, in projection into a projection plane (P2) which is orthogonal to the stacking direction (Z2).

11. Fuel cell (1) according to any one of the preceding claims, wherein: • the plates (10, 30, 50, 70) of the stack (2) include a terminal plate (70), terminating the stack (2) along the stacking direction (Z2); • a transverse groove (8) is formed in the exchange edge (71) of the end plate (70), the transverse groove (8) being connected to the centering groove (6) by opening into the centering notch (72) of the end plate (70); and • the manifold joint (90) includes a transverse joint portion (92), which is perpendicular to the stacking direction (Z2), which is formed in the transverse groove (8) and which is joined to the longitudinal joint portion (91), so that the transverse joint portion (92) is interposed between the end plate (70) and the outer manifold (100) to ensure fluidic sealing of the fluidic connection between the external manifold (100) and the stack (2).

12. Fuel cell (1) according to any one of the preceding claims, wherein: • the collector (100) includes a connector (101), comprising: • a first flared opening, covering the exchange face (5) to be fluidly connected to the exchange face (5), and • a second, narrower opening, being connected to an inlet or outlet line of the operating fluid; and • the fastening system (102) is integral with the connector (101).

13. Fuel cell (1) according to any one of the preceding claims, wherein: • the fuel cell (1) comprises a compression system, including support plates (111, 112), on either side of the stack (2) along the stacking direction (Z2); and • for fixing the collector (100), the fixing system (102) is fixed to the support plates (111, 112).

14. A method for manufacturing the fuel cell (1) according to any one of the preceding claims, the method comprising: • while the plates (10, 30, 50, 70) of the stack (2) are not yet stacked and the collector seal (90) is not yet formed, installation of a centering rail (131), which is parallel to the stacking direction (Z2) and which is suitable for being received in the respective centering notch (12, 32, 52, 72) of the plates (10, 30, 50, 70); • successive stacking of the plates (10, 30, 50, 70) to form the stack (2) while the centering rail (131) is installed, guiding the plates (10, 30, 50, 70) by mechanical cooperation of at least one of the centering notches (12, 32, 52, 72) with the centering rail (131), so that the centering rail (131) ensures centering of the plates (10, 30, 50, 70) transversely with respect to the stacking direction (Z2); • removal of the centering rail (131), once the stacking (2) is complete, by moving the centering rail (131) away from the stacking (2), transversely with respect to the stacking direction (Z2); • installation of the manifold seal (90), with the longitudinal seal portion (91) formed in the centering groove (6), once the stacking (2) has been completed and the centering rail (131) has been removed; • fluid connection of the outer manifold (100) to the stack (2), once the manifold seal (90) has been put in place, by bringing the outer manifold (100) against the stack (2) so as to cover the exchange face (5), with the manifold seal (90), including the longitudinal seal portion (91), interposed between the stack (2) and the outer manifold (100), to ensure the sealing of the fluid connection between the outer manifold (100) and the stack (2); and • fixing the external collector (100) using the fixing system (102).

15. The method according to claim 14, wherein: • the installation of the centering rail (131) includes fixing the centering rail (131) to a support plate (111) belonging to the fuel cell (1); • the successive stacking of the plates (10, 30, 50, 70) includes stacking one of the plates (10, 30, 50, 70) against the support plate (111) parallel to the stacking direction (Z2); and • the removal of the centering rail (131) includes a separation of the centering rail (131) from the support plate (111).

16. A method according to any one of claims 14 or 15, in

17. which includes the installation of the manifold gasket (90): • application of a first bead (95), made of elastomer in a non-crosslinked state, in the centering groove (6), to form the longitudinal joint portion (91); and • in-situ crosslinking of the non-crosslinked elastomer of the first bead (95), while the first bead (95) has been applied. A method according to claim 16, wherein the placement of the manifold seal (90) further comprises, once the first bead (95) has been applied: application of a second bead (96), of elastomer in a non-crosslinked state on the first bead (95), such that the second bead (96) is projecting outwards from the stack (2), relative to the exchange face (5), the elastomer of the second bead (96) having a higher viscosity, at the time the second bead (96) is applied than the viscosity of the elastomer of the first bead (95), when the first bead (95) is applied.

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