Fuel cell and method for manufacturing same

Abstract

The present invention relates to a fuel cell (1) comprising stacked plates (10, 30, 50, 70), each plate having a respective exchange edge for forming an exchange surface (5), an outer manifold fluidly connected to said exchange surface, and a manifold seal (90) surrounding the exchange surface (5) to ensure tightness of the fluid connection. To ensure that the manifold seal has a better controlled shape and is easier to apply, each plate has a respective centering notch adjacent to the exchange edge for forming a centering groove (6) in contact with the exchange surface. The manifold seal comprises a longitudinal sealing portion (91), which is formed in the centering groove and ensures tightness of the fluid connection.

Description

[Technical Field]

[0001] The present invention includes a fuel cell and a method for manufacturing such a fuel cell. [Background technology]

[0002] U.S. Patent Application Publication No. 2001055708 describes a fuel cell comprising a horizontal stack of electrochemical cell components, including fluid field plates, anode and cathode supports, anode and cathode catalysts, and a proton exchange membrane. The stack is supplied with reactive gases, such as oxygen or hydrogen, by a manifold positioned on top of the stack. A sealing system is interposed between the manifold and the stack. While the edges of the components are irregularly positioned, i.e., protruding or recessed relative to one another, the sealing system comprises a first part forming a bridge of low-temperature crosslinked silicone, which takes the form of protruding and recessed edges to form a flat, regular surface. The sealing system comprises a second part formed by a foamed silicone layer interposed between the flat, regular surface of the first part and the underside of the manifold and extending around the entire periphery of the manifold.

[0003] In practice, however, the need to use a low viscosity silicone so that it can perfectly conform to the irregularities in the stack and form bridges can mean that the silicone is wide, and so the seal thus formed, while relatively flat on the surface, is relatively wide overall and imprecisely shaped, which can accidentally obstruct part of the exchange surface between the stack and the manifold, thus reducing the efficiency of the fuel cell. Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention aims to solve the drawbacks of the prior art by proposing a new fuel cell whose manifold seal has a better controlled shape which makes the application of the manifold seal easier. [Means for solving the problem]

[0005] The present invention comprises a fuel cell, the fuel cell comprising: a stack comprising plates, the plates of which comprise flow field plates and membrane-electrode plates, stacked in a stacking direction to form an electrochemical cell, each plate being oriented perpendicular to the stacking direction and arranged flat with respect to adjacent plates, each plate having a respective exchange edge which is parallel to one another and which together form an exchange surface belonging to the stack, the exchange surface extending parallel to the stacking direction; an outer manifold fluidly connected to the stack by being applied to the stack so as to cover the exchange surface for exchange of working fluid between the outer manifold and the stack via the exchange surface; a manifold seal that frames the exchange surface and is interposed between the stack and the outer manifold to ensure a sealed fluid connection between the outer manifold and the stack; Preferably, a fastening system separate from the manifold seal, the outer manifold being fastened to the stack via the fastening system. Equipped with.

[0006] Each plate comprises a respective centering notch adjacent to the exchange edge, which together form a centering groove belonging to the stack, which tangents to the exchange surface and extends parallel to the stacking direction.

[0007] The manifold seal includes a longitudinal seal portion that is parallel to the stacking direction and formed in the centering groove such that the longitudinal seal portion is interposed between the stack and the outer manifold to ensure sealing of the fluid connection between the outer manifold and the stack.

[0008] The idea underlying the present invention is to provide a manifold seal formed within a centering groove, so that the manifold seal received inside the centering groove has a low tendency to overflow laterally during its formation, especially when the material used to form the manifold seal has a very low viscosity. When the shape of the manifold seal is well controlled, it becomes easier to form a seal that fits into the centering notches of the plate, even when some notches are recessed or protruding relative to each other. Therefore, it becomes easier to ensure sealing of the working fluid.

[0009] Another advantage is that specific centering notches can be used to ensure plate centering during stack construction. In other words, during the stacking of plates to form a stack and before the manifold seals have been formed, a centering rail can be temporarily installed. This centering rail mechanically cooperates with some of the centering notches and thus serves as a template to ensure that the corresponding plates are correctly positioned transversely to the stacking direction. This centering rail is oriented parallel to the stacking direction. During stacking, at least some of the plates whose centering notches mechanically cooperate with the rail are guided to slide along the centering rail in the stacking direction. For other plates, the rail can pass through the centering notch along the stacking direction. Once the stacking of the plates is complete, the centering rail is removed, leaving the centering notch free to form the manifold seal therein. This centering notch thus combines both the plate centering function and the reception of the longitudinal seal portion.

[0010] Preferably, at least one of the flow field plates has exchange openings formed on an exchange edge of said flow field plate, opening onto the surface of the exchange face and covered by an outer manifold, and exchange of working fluid between said outer manifold and the stack is carried out through said exchange openings.

[0011] Preferably, the plates of the stack comprise respective secondary edges parallel to the replacement edges and connected to them by centring notches.

[0012] Preferably, for at least one of the plates of the stack, the replacement edge projects outwardly from the stack relative to the secondary edge.

[0013] Preferably, for at least one of the membrane-electrode plates, the secondary edge of this membrane-electrode plate projects outwardly from the stack relative to the secondary edge of the adjacent flow field plate.

[0014] Preferably, the flow field plates comprise a primary flow field plate and a secondary flow field plate. Preferably, at least one of the primary flow field plates is adjacent to one of the secondary flow field plates to form, together with the 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 flush with each other. Preferably, for at least one of the bipolar plates, a centering notch of the primary flow field plate is recessed inward from the stack relative to a centering notch of the secondary flow field plate.

[0015] Preferably, the centering notch of at least one of the membrane-electrode plates is flush or recessed inward from the stack relative to the centering notch of an adjacent secondary flow field plate, and protrudes outward from the stack relative to the centering notch of an adjacent primary flow field plate.

[0016] Preferably, for at least one of the membrane-electrode plates, the exchange edge of this membrane-electrode plate projects outward from said stack relative to the exchange edge of the adjacent flow field plate.

[0017] Preferably, the stack further comprises peripheral seals, each peripheral seal being interposed between one of the flow field plates and one of the membrane-electrode plates in the stacking direction. Preferably, each peripheral seal comprises an exchange edge portion interposed between the exchange edge of a flow field plate and the exchange edge of a membrane-electrode plate in the stacking direction, the exchange edge portion being flush with the exchange edge of the flow field plate or recessed inward from the stack relative to the exchange edge of the flow field plate, and a recess portion interposed between the centering notch of the flow field plate and the centering notch of the membrane-electrode plate in the stacking direction, the recess portion being flush with or recessed inward from the stack relative to the centering notch of the flow field plate.

[0018] Preferably, for at least one of the plates of the stack, the centering notch has, in projection in a projection plane orthogonal to the stacking direction, a profile in the shape of an arc of a circle.

[0019] Preferably, the plates of the stack comprise end plates that terminate the stack along the stacking direction.

[0020] Preferably, a transverse groove is provided in the replacement edge of the end plate, the transverse groove being connected to the centering groove by opening into the centering notch of said end plate. Preferably, the manifold seal comprises a transverse seal portion perpendicular to the stacking direction, formed in the transverse groove, and coupled to the longitudinal seal portion, whereby the transverse seal portion is interposed between the end plate and said outer manifold to ensure a fluid-tight fluid connection between the outer manifold and the stack.

[0021] The present invention also includes a method for manufacturing a fuel cell as defined above, the method comprising the steps of: While the plates of the stack are not yet stacked and the manifold seal is not yet formed, installing a centering rail parallel to the stacking direction and receivable within a centering notch of each of the plates; successively stacking the plates to form the stack while the centering rails are installed, the centering rails guiding the plates by mechanically cooperating with at least one of the centering notches to ensure centering of the plates transverse to the stacking direction; removing the centering rails after the stack is completed by moving the centering rails away from the stack transversely to the stacking direction; positioning the manifold seal with a longitudinal seal portion formed in the centering groove after the stack is completed and the centering rail is removed; fluidly connecting the outer manifold to the stack after the manifold seal has been positioned by interposing the manifold seal including the longitudinal seal portion between the stack and the outer manifold and applying the outer manifold to the stack over an exchange surface to ensure a sealed fluid connection between the outer manifold and the stack; Preferably, a fastening system is used to fasten the outer manifold to the stack. Includes.

[0022] Preferably, installing the centering rail comprises fastening the centering rail to a support plate belonging to the fuel cell. Preferably, stacking the plates successively comprises stacking one of the plates against the support plate parallel to the stacking direction. Preferably, removing the centering rail comprises separating the centering rail from the support plate.

[0023] Preferably, disposing the manifold seal comprises: applying a first bead of elastomer in a non-crosslinked state within the centering groove to form a longitudinal seal portion; After the first bead is applied, in-situ crosslinking of the uncrosslinked elastomer of the first bead is performed. Includes.

[0024] Preferably, positioning the manifold seal further includes applying a second bead of elastomer in a non-crosslinked state on the first bead after the first bead is applied, such that the second bead protrudes outward from the stack toward the exchange surface, and the elastomer of the second bead has a higher viscosity when the second bead is applied than the viscosity of the elastomer of the first bead when the first bead is applied.

[0025] The present invention and other advantages will become apparent in light of the following description of embodiments consistent with its principles, which proceeds with reference to the accompanying drawings. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 1 is a perspective view of a fuel cell according to one embodiment of the present invention. [Figure 2] FIG. 2 is a view similar to FIG. 1 with the outer manifold removed. [Figure 3] FIG. 3 is a view similar to FIG. 1 with the outer manifold and manifold seal removed. [Figure 4] FIG. 4 shows a detail of FIG. 3 from a different perspective, in this case a low angle view. [Figure 5] FIG. 5 is a top view of a portion of a stack belonging to the fuel cell of FIGS. [Figure 6] FIG. 6 is a view similar to FIG. 5, also showing the manifold seal. [Figure 7]FIG. 7 is a perspective view similar to FIG. 1, illustrating a manufacturing process of a fuel cell. [Figure 8] FIG. 8 is a perspective view similar to FIG. 1, illustrating another process for manufacturing a fuel cell. [Figure 9] FIG. 9 is a perspective view similar to FIG. 1, illustrating another process for manufacturing a fuel cell. DETAILED DESCRIPTION OF THE INVENTION

[0027] Figures 1-3 show a fuel cell 1 according to one embodiment of the present invention. The fuel cell 1 comprises a stack 2, which is shown in more detail in Figures 4-6. The stack 2 comprises primary flow field plates 10, secondary flow field plates 30, membrane-electrode plates 50, preferably end plates 70, and a peripheral seal 80. The cell 1 also comprises an outer manifold 100, visible in Figure 1, and a manifold seal 90, visible in Figures 2 and 6. The cell 1 also advantageously comprises a compression system, visible in Figures 1-3, comprising, for example, support plates 111 and 112, tie rods 113, and springs 114.

[0028] For the manufacture of the cell 1, and in particular for the centering of the various plates 10, 30, 50, and 70, a peripheral centering template 130 shown in Figures 7 to 9 is used, which includes centering rails 131 that are at least partially removed once the stack 2 is completed.

[0029] A stacking direction Z2 is defined according to which the plates 10, 30, 50, and 70 and the seal 80 are stacked to form the stack 2. The direction Z2 is perpendicular to the plates 10, 30, 50, and 70, which are fastened to the stack 2.

[0030] As shown in FIGS. 1 to 3 , support plates 111 and 112 are disposed on either side of stack 2 along direction Z2. Springs 114 are interposed between stack 2 and support plate 112 along direction Z2. Support plate 111 abuts against stack 2 along direction Z2. Stack 2 abuts against springs 114 distributed across the surface of support plate 112. Springs 114, interposed between support plate 112 and stack 2, abut against plate 112 along direction Z2. Tie rods 113, each parallel to direction Z2, are distributed around stack 2 and connect support plates 111 and 112 together, holding the tie rods in position relative to each other along direction Z2 and thus maintaining stack 2 in compression along direction Z2 under the action of springs 114. Springs 114 advantageously allow for dimensional variations of stack 2 along direction Z2 that may occur during use of the cell, particularly under the influence of thermal stresses. In this example, six tie rods 113 and eight springs 114 are provided, but a different number of these elements may be provided. Alternatively, another type of compression system may be provided. For example, the compression system may alternatively comprise support plates on both sides of the stack, the entire stack and the support plates being received in a housing, and a spring being interposed between a face of the housing 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 WO 2007 / 080472. Other compression systems are described in document US 20090162728, or without springs, in document US 20100261088, or in document EP 1 597 786.

[0031] Each plate 10, 30, 50, and 70 is flat along 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 FIGS. 3 and 4 , each plate 10, 30, 50, or 70 is positioned flat relative to its adjacent, i.e., immediately adjacent, plate. Once positioned flat, the plates 10, 30, 50, or 70 are stacked edge-to-edge with the adjacent plate, possibly with one of the seals 80 interposed between the two adjacent plates. More specifically, each peripheral seal 80 is interposed between one of the membrane-electrode plates 50 and one of the flow field plates 10 or 30. Each peripheral seal 80 extends flat between the associated plates along a plane perpendicular to the stacking direction Z2. In the illustrated example, adjacent flow field plates 10 and 30 are stacked without a peripheral seal 80 interposed between them.

[0032] The different plates of the stack 2 are arranged in a specific order along the stacking direction Z2 to form groups of adjacent plates, with each group of adjacent plates forming a respective electrochemical cell. Each electrochemical cell of the stack 2 comprises, in this order along the direction Z2, a secondary flow field plate 30, a possible peripheral seal 80, a membrane-electrode plate 50, another possible peripheral seal 80, and a primary flow field plate 10. For operation of the electrochemical cells, the stack 2 is designed to be supplied with working fluids, including a cathode reactant fluid containing, for example, hydrogen, an anode reactant fluid containing, for example, oxygen, which may be contained in air, and, optionally, a cooling fluid. In each electrochemical cell, the cathode reactant fluid reacts with the anode reactant fluid to generate electricity. The cooling fluid serves to cool the stack 2. It is further realized to remove these working fluids and / or products resulting from the reaction of these working fluids after they pass through the stack 2.

[0033] In this example, for simplicity, only nine electrochemical cells are shown, however, in practice the fuel cell 1 may have a larger number of cells, for example 50-500.

[0034] Each plate 10, 30, 50, and 70 has an outer periphery 3 extending in a plane perpendicular to the direction Z2. Each plate 10, 30, 50, and 70 extends only within its outer periphery 3. Here, each outer periphery 3 is approximately rectangular in shape. Advantageously, the outer peripheries 3 of each plate of the same type in the stack 2 are of the same or similar shape and are aligned and stacked with the outer peripheries 3 of all other plates of the same type along the stacking direction Z2, i.e., along the direction Z2. For example, all membrane-electrode plates 50 have the same outer periphery 3 and are stacked with the outer peripheries 3 of other membrane-electrode plates 50 along the stacking direction Z2. For example, all primary flow field plates 10 have the same outer periphery 3 and are stacked with the outer peripheries 3 of other primary flow field plates 10, such as the outer peripheries 3 of plates 10, which may be different from those of plates 50, along the stacking direction Z2. In particular, the periphery 3 of a first type of plate is, for all or part, recessed toward the inside of the stack 2 or protrudes toward the outside of the stack 2 relative to the periphery of another type of plate. For example, the periphery 3 of the membrane-electrode plate 50 protrudes toward the outside of the stack 2 relative to the periphery 3 of the flow field plate 10.

[0035] The joining of the peripheries 3 of all plates 10, 30, 50 and 70 of this stack forms different side surfaces 4 of the stack 2, here four side surfaces 4, parallel to the direction Z2, since the peripheries 3 of the plates of the stack 2 have an approximately rectangular shape. Parts of the peripheries 3 of the plates 10, 30, 50 and 70 are recessed or protruding, so that the side surfaces 4 are irregular, the recessed peripheries 3 forming transverse grooves perpendicular to the stacking direction Z2 and the protruding peripheries 3 forming ridges perpendicular to the stacking direction Z2 and parallel to these grooves.

[0036] As can be seen better in FIGS. 2 and 3 , at least one of the side surfaces 4 of the stack 2 forms at least one exchange surface 5, at least one centering groove 6, and at least one secondary surface 7. For example, at least one of the side surfaces 4 of the stack 2 forms a single exchange surface 5, two centering grooves 6, and two secondary surfaces 7. The present description and drawings show only one of the side surfaces 4 of the stack 2 provided with such elements. However, preferentially, one or more other side surfaces 4 also have such elements or at least a centering groove 6. Typically, two opposing side surfaces 4 of the stack 2 must form an inlet and an outlet for a given working fluid with such elements. It can also be realized that on one side surface 4, two exchange surfaces 5 are arranged side by side according to the tangential direction of said surface, which is perpendicular to the stacking direction Z2, in this case using, for example, three or four centering grooves 6 and two or three secondary surfaces 7.

[0037] In addition to said at least one exchange surface 5, the stack may, in a known manner, comprise one or more internal galleries or internal manifolds, each internal gallery being formed from superimposed openings arranged in the stack of plates for the circulation and distribution of one or more other working fluids.

[0038] For each exchange surface 5, a normal direction Y2 directed towards the outside of the stack 2, perpendicular to the surface 5 and to the direction Z2, and a tangential direction X2 parallel to the exchange surface 5 and perpendicular to the direction Z2 are defined.

[0039] Preferably, the exchange surface 5, the groove 6 and the secondary surface 7 extend from one end of the stack 2 to the other along the direction Z2 and are parallel to the direction Z2.

[0040] Each centering groove 6 extends parallel to the direction Z2 and is recessed into the stack 2 so as to open in the normal direction Y2. An exchange surface 5 is located between two grooves 6 and is defined by the grooves 6 in the tangential direction X2. Each groove 6 is located between the exchange surface 5 and one of the secondary surfaces 7. In the tangential direction X2, the secondary surface 7 is preferably defined by the groove 6 and extends, for example, to one end of the side surface 4. Preferably, the exchange surfaces 5 and the secondary surfaces 7 are parallel to each other and to the tangential direction X2.

[0041] On the same side 4 as that supporting the exchange surface 5, the stack also preferably includes a plurality of transverse grooves 8, here two transverse grooves 8. Each transverse groove 8 is recessed into the stack 2 so as to open in the normal direction Y2. Each transverse groove 8 connects two centering grooves 6 together. For this purpose, each transverse groove 8 preferably extends perpendicular to direction Z2, in particular parallel to direction X2. The exchange surface 5 is located between the two grooves 8 and is defined by the grooves 8 in the stacking direction Z2. The grooves 6 and 8 together frame the exchange surface 5 according to a closed contour.

[0042] As seen in FIG. 2, manifold seal 90 is preferably integral with stack 2, while manifold 100 is attached to stack 2 against seal 90, as shown in FIG.

[0043] Advantageously, manifold seal 90 is separate from manifold 100. Preferably, manifold seal 90 is not attached to manifold 100, particularly in that seal 90 is not adhered to or fixed to manifold 100. Preferably, manifold 100 abuts only against seal 90.

[0044] Preferably, the seal 90 is adhered and / or secured to the stack 2 so as to be integral with the stack 2 .

[0045] The manifold seal 90 frames the exchange surface 5. To this end, the manifold seal 90 comprises two longitudinal seal portions 91 and two transverse seal portions 92. Each longitudinal seal portion 91, as seen in cross section in FIG. 6 , extends parallel to the stacking direction Z2. The portions 91 are arranged on either side of the surface 5 in the direction X2, and each is formed in one of the grooves 6 across the entire height of the surface 5 in the direction Z2. Each transverse seal portion 92 connects the two longitudinal seal portions 91 together and extends, for example, parallel to the tangential direction X2. The portions 92 are joined to the portions 91 at both ends of the portion 92. The portions 92 are then arranged on either side of the surface 5 in the direction Z2. Overall, the manifold seal 90 has a quadrilateral shape or at least a closed contour around the surface 5.

[0046] Preferably, each longitudinal seal portion 91 completely fills the cross section of groove 6 that it occupies over the portion of groove 6 that extends along surface 5, with portion 91 following the shape of the bottom of groove 6. Similarly, preferably, each transverse seal portion 92 completely fills the cross section of groove 8 that it occupies over the portion of groove 8 that extends along surface 5, with portion 92 following the shape of the bottom of groove 8. As can be seen in FIG. 6 , in direction Y2, seal 90 protrudes slightly to ensure intimate contact with manifold 100. In particular, longitudinal seal portion 91 protrudes slightly from groove 6 in direction Y2. In particular, transverse seal portion 92 protrudes slightly from groove 8 in direction Y2.

[0047] The exchange surface 5 is configured to allow the exchange of at least one working fluid, preferably a single working fluid, with the outer manifold 100. For this purpose, the outer manifold 100 is fluidly connected to the stack 2, in particular to the exchange surface 5, preferably only to the surface 5. To be fluidly connected to the stack 2, the manifold 100 is attached to the stack 2 so as to cover the exchange surface 5, as shown in Figure 1. To ensure the tightness of this fluid connection, a seal 90 is interposed between the manifold 100 and the stack 2 in the direction Y2.

[0048] By "exchange" it is meant either the entry of working fluid into the stack 2 via the exchange surface 5, which is then supplied by the outer manifold 100, or the removal of working fluid from the inside of the stack 2 via the exchange surface 5, which is then collected by the outer manifold 100. At the level of the surface 5, the exchange of working fluid takes place parallel to the normal direction Y2.

[0049] In practice, as shown in FIG. 1 , the manifold 100 comprises a connector 101, e.g., having a funnel shape. A first opening of the connector 101, preferably flared, covers the surface 5 and is fluidly connected to it. A second opening of the connector 101, preferably narrower than the first opening, is preferably connected to an inlet or outlet pipe for the working fluid. The first opening, connected to the exchange surface 5, is preferably defined by a closed contour edge belonging to the connector 101, which advantageously extends in a plane X2, Z2 perpendicular to the normal direction Y2 and has a shape complementary to the shape of the grooves 6 and 8. To ensure the tightness of the connection, this closed contour belonging to the manifold contacts the seal 90 over the entire surface 5, particularly with the longitudinal seal portion 91 and the transverse seal portion 92 of the seal 90. The manifold seal 90 is preferably made of an elastomer, e.g., silicone, that is slightly elastic to fit the manifold 100 and thus ensure tightness. The closed contour edge defining the first opening of the connector 101 thus has a support surface on the seal 90 that is in close contact with the entire closed contour, and thus the seal 90 extends along the same contour. The support surface of the closed contour edge defining the first opening of the connector 101 can be a flat surface extending in a plane X2, Z2 perpendicular to the normal direction Y2, and thus has the shape of a strip that follows the closed contour. This support surface can have a plurality of ribs that are undulating relative to the plane X2, Z2 perpendicular to the normal direction Y2, and preferably a plurality of ribs, if present, that are undulating along the contour and parallel to one another. Such ribs that extend along this contour therefore penetrate into the material of the seal 90 along the entire closed contour, thereby increasing the reliability of the tightness of the contact between the connector 101 and the seal 90.

[0050] Manifold 100 may also preferably include a fastening system 102 integral with connector 101 and capable of fastening manifold 100 to cells 1 and / or stacks 2 .

[0051] The fastening system 102 is separate from the manifold seal 90. This allows the manifold seal 90 to ensure exclusively the sealing function. In other words, the manifold seal 90 does not perform any fastening function. This allows each of the functions to be well separated, in that sealing and fastening are ensured by different parts, and therefore provides a particularly simple and reliable design, as well as being very easy and quick to implement.

[0052] Here, fastening system 102 is designed to be fastened to cell 1 by being fastened to plates 111 and 112. In other words, in this case, manifold 100 is fastened to stack 2 in that fastening system 102 is fastened to plates 111 and 112. Alternatively, manifold 100 can be fastened to stack 2 in that fastening system 102 is fastened to only one of plates 111 and 112, or to another element of cell 1, in particular an element of the compression system, or to the housing of cell 1, or to stack 2 itself. Preferably, fastening system 102 fastens manifold 100 to stack 2 without being fastened to groove 6 reserved for manifold seal 90.

[0053] Preferably, the fastening system 102 comprises a base 103 to which the fastening system is fastened to a fastening edge 115 belonging to the plate 111. Preferably, the base 103 is attached to the fastening edge 115 parallel to the normal direction Y2, the fastening edge 115 being parallel to the exchange surface 5 in direction Z2 and / or in its extension.

[0054] Preferably, the fastening system 102 comprises a base 104 to which the fastening system is fastened 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 the exchange surface 5 and / or in its extension in direction Z2. The connector 101 is held pressed against the surface 5 in opposite directions in direction Y2 by the bases 103 and 104. Preferably, at least one of the bases 103 or 104 is movable in direction Z2 relative to the other base and / or relative to the connector 101 to allow dimensional variations of the stack 2 in direction Z2 during use.

[0055] At least one of the bases of such a fastening system can be fastened to a fastening edge belonging to one or other of the end plates 70, as will be described below.

[0056] Preferably, the stack 2 comprises exactly two end plates 70, which are provided at the ends of the stack 2 on either side in the stacking direction Z2. In other words, each end plate 70 terminates the stack in the direction Z2. This does not exclude that other plates may contact the stack 2 on either side by contacting the plates 70. The end plates 70 absorb the force applied to the stack 2 by the compression system. In this example, the stack 2 is supported against the support plate 111 in the opposite direction in the direction Z2 via one of the two end plates 70, and the stack 2 is supported against the spring 114 via the other of the two end plates 70. Preferably, the end plate 70 is electrically insulating, has an electrically insulating coating, or has at least one part in contact with the stack that is electrically insulating, taking into account the currents contained in the stack 2. Advantageously, the plate 111 as well as the end plate 70 supported against the support plate 111 can be traversed in the direction Z2 by passages for the working fluid to supply and / or remove working fluid from the stack 2. Thus, additional connections for the working fluid can be made via the end plate 70 in addition to those made using the exchange surface 5 and the outer manifold 100.

[0057] Preferably, each membrane-electrode plate 50 comprises a membrane-electrode assembly and, in certain embodiments, an outer frame forming the outer periphery 3 of the plate 50. The outer frame is preferably electrically insulating, given the currents contained within the stack 2. The membrane-electrode plate 50 also comprises a membrane surrounded by the frame, which allows proton exchange from one side of the plate 50 to the other. On one side, here oriented in direction Z2, the membrane is covered by a cathode catalyst layer, which is itself covered by a cathode gas diffusion layer. On the other side, here oriented opposite direction Z2, the membrane is covered by an anode catalyst layer, which is itself covered by an anode gas diffusion layer. The membrane of each plate 50 is the site of an electrochemical reaction requiring an anode reactive fluid to be applied to the side supporting the anode catalyst and a cathode fluid to be applied to the side supporting the cathode catalyst, creating a potential difference across the membrane and ultimately generating electricity for the fuel cell. Alternatively, the periphery 3 of the plate 50 is formed by the membrane itself and the plate 50 is frameless.

[0058] Preferably, for the manufacture of cell 1, each membrane-electrode plate 50 is pre-assembled before being added to stack 2, i.e., the aforementioned components of plate 50 are already fastened to each other when plate 50 is added to stack 2.

[0059] Preferably, each flow field plate 10 and 30 is electrically conductive, taking into account the currents contained in the stack 2. On one of its faces, each plate 10 and 30 forms a flow field, i.e., a plurality of channels that cross the stack 2 transversely to the stacking direction Z2, guiding the circulation of the working fluid in each channel. 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 an electrochemical reaction with the adjacent plate 50.

[0060] Every primary flow field plate 10 is dedicated to guiding the circulation of a first working fluid, e.g., a cathode reactant fluid, and its channels face the corresponding gas diffusion layer of the adjacent plate 50. Here, this is the cathode diffusion layer of the plate 50. In this sense, the primary flow field plate 10 can be qualified as a polar plate, here a cathode. In this example, the channels of the primary flow field plate 10 face the adjacent plate 50 in the opposite direction to direction Z2. For example, the channels of the primary flow field plate 10 are oriented generally parallel to direction Y2. Due to electrochemical reactions within the adjacent plate 50, each conductive primary flow field plate 10 assumes the cathode potential of the considered electrochemical cell. A peripheral seal 80 interposed between the plate 10 and the adjacent plate 50 ensures gas tightness between these two plates 10 and 50, preventing the first working fluid from leaking out of the stack at the outer periphery 3 of the plates 10 and 50. To this end, the seal 80 advantageously forms a closed contour extending along the periphery 3 and is flush with the periphery 3 or, as the case may be, slightly recessed inwards relative to the periphery 3 .

[0061] Every secondary flow field plate 30 is dedicated to guiding the circulation of a second working fluid, e.g., an anode reactant fluid, and its channels face the corresponding gas diffusion layer of another plate 50 adjacent to this plate 30. In this case, it is the anode diffusion layer of said plate 50. Therefore, adjacent plates 10 and 30 separate the two adjacent plates 50. The secondary flow field plate 30 may qualify as a polar plate, here an anode. In this example, the channels of the secondary flow field plate 30 face the plate 50 adjacent to plate 30 in direction Z2. In this example, the channels of plate 30 are oriented generally parallel to direction Y2 or parallel to direction X2. Due to the electrochemical reaction in the adjacent plate 50, each conductive plate 30 is at the anode potential of the electrochemical cell under consideration. A peripheral seal 80 interposed between a plate 30 and an adjacent plate 50 ensures tightness between these two plates 30 and 50 and prevents the second working fluid from leaking out of the stack at the periphery 3 of said plates 30 and 50. To this end, the seal 80 advantageously forms a closed contour extending along the periphery 3.

[0062] 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, and the channels of the flow field plates 10 and 30 facing this membrane-electrode plate 50 are surrounded by a peripheral seal 80. From one electrochemical cell to an adjacent electrochemical cell, the channels of the plate 10 of the first electrochemical cell face away from the channels of the plate 30 of the second electrochemical cell. Adjacent flow field plates 10 and 30 belonging to two adjacent cells together constitute a bipolar plate. Due to electrical conduction between these two adjacent plates 10 and 30, the two polar plates are at the same potential.

[0063] Advantageously, between adjacent flow field plates 10 and 30, i.e. within the bipolar plates, another circulation field can be formed by the plates 10 and 30. This other circulation field comprises channels defined by the plates 10 and 30 for directing the circulation of a third working fluid, i.e. cooling fluid, between the flow field plates 10 and 30 and thus cooling the stack 2 during its use.

[0064] In this example, the bipolar plates of the stack are composed of two separate plates 10 and 30, which are attached to each other. For example, each plate 10 and 30 is composed of a metal sheet, preferably stamped to form the circulation field. Alternatively, all or part of the plate 10 or 30 may be formed from a machined plate of metal, graphite, or other conductive material. Preferably, for each bipolar plate, the two flow field plates 10 and 30 are pre-assembled, i.e., already fastened 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 welding or brazing to each other.

[0065] Preferably, for the manufacture of cell 1, each seal 80 is pre-assembled with one of plates 10, 30, or 50. Preferably, before being added to stack 2, each bipolar plate carries two seals 80: one protruding in direction Z2 on plate 30 and one protruding in the opposite direction on plate 10. Alternatively, each membrane-electrode plate 50 can carry two seals 80: one protruding in direction Z2 to be interposed between plate 50 and the adjacent flow field plate 10, and one protruding in the opposite direction on the other side of membrane-electrode plate 50 to be interposed between membrane-electrode plate 50 and the adjacent flow field plate 30. Preferably, each seal 80 is overmolded, cast, or printed directly onto the plate 10, 30, or 50 that carries it, which facilitates assembly. However, free seals can be used.

[0066] Furthermore, the plate 50 may be bonded 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 a simple adhesive bond or a double-sided bond.

[0067] At its respective periphery 3, each plate 10, 30, 50, and 70 has several edges, among which at least one exchange edge and at least one secondary edge, as well as several centering notches, formed on the periphery 3 of said plate. In other words, the exchange edge, the secondary edge, and the centering notch belong to the periphery 3 of the associated plate and constitute part of said plate. The exchange edges are intended to be covered by the extent of the manifold 100 and are therefore inside the closed contour of the seal 90. The centering notch is intended to consecutively ensure a first function, i.e., to ensure the guiding and centering of the plate 10, 30, 50, or 70 that carries it during the addition of said plate to the stack 2, by cooperating with or at least being traversed by one of the rails 131, and a second function, i.e., to accommodate the longitudinal sealing portion 91 of the seal 90 for sealing with the manifold 100 after the stack 2 is completed.

[0068] As shown in more detail in FIG. 4, each primary flow field plate 10 has an exchange edge 11, two centering notches 12 and two secondary edges 13; each secondary flow field plate 30 has an exchange edge 31, two centering notches 32 and two secondary edges 33; each membrane-electrode plate 50 has an exchange edge 51, two centering notches 52 and two secondary edges 53; and as shown in FIG. 2, each end plate 70 has an exchange edge 71, two centering notches 72 and two secondary edges 73.

[0069] Preferentially, for each plate, the centering notch is adjacent to the exchange edge and the secondary edge, i.e., at the end of the exchange edge and at the end of the secondary edge, connecting said exchange edge and said secondary edge together. In other words, advantageously, each centering notch is located between one of the exchange edges and one of the secondary edges of the plate under consideration. Here, each plate of the stack 2 comprises only two centering notches, only one exchange edge, and only two secondary edges. Advantageously, the exchange edge is parallel to the tangential direction X2. Advantageously, the secondary edge adjacent to this exchange edge is parallel to the tangential direction X2, and the centering notch adjacent to this exchange edge is recessed in the opposite direction to the exchange edge or opens in the direction Y2.

[0070] During manufacture, each rail 131 extends parallel to direction Z2. Each centering notch 12, 32, 52, and 72 corresponds to rail 131 in direction X2 and engages across or around rail 131 in direction Y2, so that rail 131 is at least partially received in each of notches 12, 32, 52, and 72, as shown in FIGS. 5 and 7-9. To be able to cooperate with rail 131 by sliding in direction Z2 during manufacture, at least some of centering notches 12, 32, 52, and 72, i.e., centering notches 32, 52, and 71 here, are "contacting centering notches," which have a shape complementary to that of rail 131 so as to match the shape of rail 131 or at least contact rail 131 to center the associated plate in direction X2 and / or Y2 relative to rail 131. Preferably, the other centering notch, i.e., here notch 12, is a "non-contacting centering notch", which allows passage of rail 131 and is traversed only by rail 131 during manufacture, and does not necessarily have to be complementary to rail 131, but merely recessed enough and / or wide enough to be traversed by rail 131 and maintain a certain distance from rail 131. Centering notches 12, 32, 52, and 72 are also shaped to allow removal of rail 131 once stack 2 is completed by moving the rail away from stack 2 in direction Y2.

[0071] In this example, as seen in FIGS. 5 and 7-9, the rail 131 has a cylindrical shape with a circular base centered on an axis parallel to the Z2 direction. Preferably, as clearly seen in FIGS. 5 and 6, for each plate, the centering notch 12, 32, 52, or 72 has a profile in the shape of an arc of a circle when projected on a projection plane P2 perpendicular to the stacking direction Z2. Plane P2 is parallel to the plane on which FIGS. 5 and 6 are drawn. By "profile" we mean the edges of the notch. In other words, the centering notch is preferably rounded, allowing the notch to serve both to center the plate during the manufacture of the cell 1 and to receive the longitudinal seal portion 91 of the seal 90. However, other profiles, such as "U," "V," etc., can be provided. If the rail 131 has a shape other than those provided herein, another corresponding shape can be provided for the centering notch. In this example, the profile of the edge of the contacting centering notch is of the same nature as the profile in the cross section of the rail 131, so as to allow contact along a segment of this edge profile of the notch having a certain length. However, the profile of the edge of the contacting centering notch and the profile of the cross section of the rail 131 can be such that only point contact is ensured, preferably sufficient point contact for contact between the edge of the contacting centering notch and the rail 131 to accurately determine the relative position of the notch with respect to the rail in the two lateral directions X2 and Y2.

[0072] As can be seen in FIG. 4 , each peripheral seal 80 preferably comprises an exchange edge portion 81 interposed in direction Z2 between the exchange edge 11 or 31 of the adjacent plate 10 or 30 and the exchange edge 51 of the adjacent plate 50. The exchange edge portion 81 extends parallel to these exchange edges 11, 31, 51 of the adjacent plates. Each peripheral seal 80 preferably comprises a secondary edge portion 83 interposed in direction Z2 between the secondary edge 13 or 33 of the adjacent flow field plate 10 or 30 on the one hand and the secondary edge 53 of the adjacent plate 50 on the other hand. The secondary edge portion 83 extends parallel to these secondary edges. Each peripheral seal 80 preferably comprises a recessed portion 82 interposed in direction Z2 between the notch 12 or 32 of the adjacent plate 10 or 30 and the notch 52 of the adjacent plate 50. The recessed portions 82 extend along these centering notches and preferably have a profile similar to that of these centering notches, in order to be able to be traversed by the rail 131, in particular during manufacture. Preferentially, for each seal 80, the recessed portions 82 are adjacent to the replacement edge portion 81 and the secondary edge portion 83, i.e., at the end of the portion 81 and at the end of the portion 83 in order to connect the portions 81 and 83 together. In other words, advantageously, each recessed portion 82 is between the replacement edge portion 81 and the secondary edge portion 83, respectively. Here, each seal 80 comprises only two recessed portions 82, only one replacement edge portion 81 and only two secondary edge portions 83, corresponding to the number of replacement edges, secondary edges and centering notches of each plate. Advantageously, the replacement edge portions 81 are parallel to the tangential direction X2. Advantageously, the secondary edge portion 83 adjacent to this exchange edge portion 81 is parallel to the tangential direction X2, and the recessed portion 82 adjacent to this exchange edge portion 81 is recessed relative to this exchange edge portion 81 in the opposite direction to Y2 or opens in the direction Y2.

[0073] In this example, the recessed portion 82 has, in projection on the projection plane P2, a profile in the shape of an arc of a circle, or more generally, a profile of the same shape as or corresponding to that of the adjacent centering notch 12, 52 or 72 belonging to the plate 10, 50 or 70, respectively, as described above.

[0074] Consecutive exchange edges 11, 31, 51, and 71 of plates 10, 30, 50, or 70 are overlapped in direction Z2. For this particular case, the term "overlapped" has a special meaning in that it does not exclude that, as will be preferentially explained below, in some cases, some exchange edges may be recessed and others may protrude in direction Y2. However, "overlapped" indicates that, as a whole, the exchange edges extend in the same plane perpendicular to direction Y2. Except for this particular case and some other cases described below, the term "overlapped" is used in its ordinary sense.

[0075] The exchange edges together form the exchange surface 5 or one of the exchange surfaces. The exchange surface 5 is therefore not necessarily flat and can therefore have grooves corresponding to, in particular, recessed exchange edges. If a seal 80 is provided, the exchange edge portion 81 also belongs to this exchange surface 5. Preferably, the overlapping exchange edges 11, 31, 51, and 71 in the direction Z2 are parallel to one another. Preferably, the overlapping exchange edges 11 of the primary flow field plates 10 in the direction Z2 are arranged in the same plane parallel to the direction Z2, are arranged at the same position in the tangential direction X2, or even have the same length in the direction X2. Preferably, the overlapping exchange edges 31 of the secondary flow field plates 30 in the direction Z2 are arranged in the same plane parallel to the direction Z2, are arranged at the same position in the tangential direction X2, or even have the same length in the direction X2. Preferably, the overlapping exchange edges 51 of the membrane-electrode plates 50 in the direction Z2 are arranged in the same plane parallel to the direction Z2, are arranged at the same position in the tangential direction X2, or even are of the same length in the direction X2. Preferably, the overlapping exchange edges 71 of the end plates 70 in the direction Z2 are arranged in the same plane parallel to the direction Z2, are arranged at the same position in the tangential direction X2, or even are of the same length in the direction X2.

[0076] The consecutive secondary edges 13, 33, 53, and 73 of the plates are overlapped in the direction Z2. Even in this case, "overlapped" has a special meaning in that, as explained below, the term does not exclude that, in some cases, some secondary edges are recessed and others protrude in the direction Y2. However, "overlapped" means that the secondary edges as a whole extend in the same plane perpendicular to the direction Y2. The secondary edges together form one of the secondary surfaces 7. If a seal 80 is provided, the secondary edge portion 83 also belongs to this secondary surface. Preferably, the overlapped secondary edges 13, 33, 53, and 73 in the direction Z2 are parallel to one another. Preferably, the overlapped secondary edges 13 of the primary flow field plate 10 in the direction Z2 are arranged in the same plane parallel to the direction Z2, are arranged at the same position in the tangential direction X2, or even are of the same length in the direction X2. Preferably, the overlapping secondary edges 33 of the secondary flow field plates 30 in the direction Z2 are arranged in the same plane parallel to the direction Z2, are arranged at the same position in the tangential direction X2, or even have the same length in the direction X2. Preferably, the overlapping secondary edges 53 of the membrane-electrode plates 50 in the direction Z2 are arranged in the same plane parallel to the direction Z2, are arranged at the same position in the tangential direction X2, or even have the same length in the direction X2. Preferably, the overlapping secondary edges 73 of the end plates 70 in the direction Z2 are arranged in the same plane parallel to the direction Z2, are arranged at the same position in the tangential direction X2, or even have the same length in the direction X2.

[0077] The successive centering notches 12, 32, 52, and 72 of the plates are overlapped in the direction Z2. Here, too, "overlapped" has a special meaning in that it does not exclude that, in some cases, some centering notches may be recessed and others may protrude in the direction Y2, as will be preferentially explained below. Nevertheless, "overlapped" indicates that the centering notches are aligned along the same axis parallel to the axis Z2. The centering notches together form one of the centering grooves 6. If a seal 80 is provided, the recessed portion 82 also belongs to this centering groove. Preferably, the overlapped notches 12 of the primary flow field plate in the direction Z2 are identical and are located at the same position in the directions X2 and Y2. Preferably, the overlapped notches 32 of the secondary flow field plate 30 in the direction Z2 are identical and are located at the same position in the directions X2 and Y2. Preferably, the overlapping notches 52 of the membrane-electrode plates 50 in the direction Z2 are identical and are located at the same positions in the directions X2 and Y2. Preferably, the overlapping notches 72 of the end plates 70 in the direction Z2 are identical and are located at the same positions in the directions X2 and Y2.

[0078] Advantageously, at least some of the flow field plates 10 and 30 form exchange openings 19. Each opening 19 opens onto one of the exchange edges 11 and / or 31 in the normal direction Y2, i.e. onto the surface of the exchange surface 5 formed by these exchange edges 11 and 31. The openings 19 therefore open onto the inside of the manifold 100, in particular the inside of the connector 101, and are covered by the manifold 100, in particular the connector 101, and framed by the seal 90. Preferably, each edge 11 and / or 31 comprises a row of openings 19, said rows being parallel to the direction X2, so that the assembly formed by the stack of edges 11, 31 presents a grid of openings 19 extending in the directions X2 and Z2 over all or most of the exchange surface 5.

[0079] The exchange openings 19 fluidly connect the outer manifold 100 with the reaction working fluid circulation field of the plate 10, or with the reaction working fluid circulation field of the plate 30, or with the cooling working fluid circulation field formed between the adjacent plates 10 and 30. For this purpose, each exchange opening 19 leads to a plurality of channels of one of the associated circulation fields. Stacks outside the exchange surface 5 advantageously do not have exchange openings 19. The exchange of working fluid between the outer manifold 100 and the stack 2 is therefore carried out via exchange openings 19 provided on the surface 5 to which the manifold 100 is connected. In this example, the exchange openings 19 are formed exclusively by the plates 10 on their respective exchange edges 11. For a given exchange surface 5 corresponding to a given outer manifold 100, all openings 19 opening into this exchange surface communicate exclusively with the same working fluid circulation field for all electrochemical cells covered by this exchange surface 5.

[0080] Preferably, as can be seen in Figures 2 and 3, a transverse groove 8 is each formed on a respective replacement edge 71 of one of the end plates 70. For each of these end plates 70, the transverse groove 8 therefore connects together the centering notches 72 of the end plates 70 considered, and therefore the centering grooves 6, so as to open into each of these centering notches 72 of the end plates 70 considered.

[0081] Preferably, for at least one of the plates of the stack 2, and preferably for all plates of the stack 2, the exchange edge 11, 31, 51, or 71 of the associated plate protrudes slightly toward the outside of the stack 2, i.e., in the direction Y2, relative to the adjacent secondary edge 13, 33, 53, or 73. Thus, in FIG. 5 , the exchange edge 11, 31 of each flow field plate 10, 30 is shown to protrude toward the outside of the stack 2, i.e., in the direction Y2, relative to the adjacent secondary edge 13, 33 of the same flow field plate 10, 30, by an amount referred to as the exchange edge offset “d1-3,” which is preferably between 0.05 millimeters and 3 millimeters, preferably between 0.2 millimeters and 1 millimeter. As a result, when the longitudinal seal portions 91 are formed and / or when they are compressed by the manifold 100, the possibility of said seals protruding onto the sides of the exchange surface 5 and of said seals accidentally blocking the exchange openings 19 is low. Alternatively, the exchange edge may be aligned with the secondary edge, ie extending along the same axis in the direction X1.

[0082] Preferably, for at least one of the membrane-electrode plates 50, and preferably for all of the membrane-electrode plates 50 of the stack 2, the exchange edge 51 of the membrane-electrode plate 50 projects towards the outside of 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. Preferably, for at least one of the membrane-electrode plates 50, and preferably for all of the membrane-electrode plates 50 of the stack 2, the secondary edge 53 of the membrane-electrode plate 50 projects towards the outside of 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. These arrangements advantageously make it possible to 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. 5 shows that the exchange edge 51 of each membrane-electrode plate 50 protrudes toward the outside of 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 referred to as the membrane-electrode plate offset "d50," which is preferably between 0.1 and 2 millimeters, preferably between 0.2 and 1 millimeter. Similarly, for all membrane-electrode plates 50 of the stack 2, the secondary edge 53 of the membrane-electrode plate 50 protrudes toward the outside of 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 the membrane-electrode plate offset "d50," which is preferably between 0.1 and 2 millimeters, preferably between 0.2 and 1 millimeter.

[0083] Preferably, for at least one, and preferably for all, 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 flush with each other, i.e. at the same level in the direction Y2. Preferably, similarly, the secondary edge 13 of the primary flow field plate 10 and the secondary edge 33 of the secondary flow field plate 30 are flush with each other, i.e. at the same level in the direction Y2.

[0084] Preferably, for at least one of the bipolar plates, and preferably for all of said plates, the centering notches 12 of the primary flow field plate 10 are recessed towards the inside of the stack 2, i.e. in the opposite direction to direction Y2, relative to the centering notches 32 of the secondary flow field plates 30. The centering notches 32 of the secondary flow field plates 30 may also be smaller in size in directions X2 and Y2 than the centering notches 12 of the primary flow field plates 10. This ensures that, during the manufacture of cell 1, for each bipolar plate, it is the centering notches 32 of the secondary flow field plates 30 that will provide lateral support on the centering rails 131 to ensure lateral positioning of the bipolar plate, and therefore can be qualified as a centering notch with contact, while the centering notch 12 remains separate from the centering rails 131, being crossed by the rails 131 in direction Z2, and therefore can be qualified as a centering notch with contact. This is particularly possible when bipolar plates are constructed from pre-assembled plates 10 and 30 and added together to the stack, or when the stack is made by stacking pre-assembled electrochemical cells. Thus, FIG. 5 shows that for at least one, and preferably all, of the bipolar plates, the centering notch 12 of the primary flow field plate 10 is recessed toward the inside of the stack 2, i.e., in the opposite direction to direction Y2, relative to the centering notch 32 of the secondary flow field plate 30, by an amount referred to as the centering notch offset "d12-32," which is preferably between 0.1 and 1 millimeter, preferably between 0.2 and 0.6 millimeters. Naturally, this centering 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, for example, the fact that the primary flow field plate 10 is a cathode or anode plate, and therefore the secondary flow field plate 30 is an anode or cathode plate, respectively.

[0085] Preferably, the centering notch 52 of at least one or all of 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 or all of the membrane-electrode plates 50 may additionally be of the same size in the directions X2 and Y2 as the centering notch 32 of the adjacent secondary flow field plate 30. Thus, during manufacture of the cell 2, the centering notch 52 will provide support on the centering rails 131 to ensure lateral positioning of the plate 50 when it is added to the stack 2, and therefore may also qualify as a centering notch with contact.

[0086] In a variant, the centering notch 52 of at least one or all of the membrane-electrode plates 50 can be slightly recessed toward the inside of the stack 2 relative to the centering notch 32 of the adjacent secondary flow field plate 30, and thus in this case can qualify as a non-contact centering notch. Preferably, the centering notch 52 then protrudes toward the outside of the stack 2 relative to the centering notch 12 of the adjacent primary flow field plate 10. In this case, the centering notch 52 can also have an intermediate size in the directions X2 and Y2 between the notches 12 and 32. In this case, to ensure centering of the plates 50 during stacking, for example, the membrane-electrode plate 50 is pre-assembled with another plate having a contacting centering notch, here, for example, the adjacent secondary flow field plate 30. To align the membrane-electrode plate 50 with other plates for the purpose of pre-assembly thereof, or to stack the membrane-electrode plates 50 without pre-assembly, centering of the membrane-electrode plate 50 can be ensured, for example, by optical alignment or by a geometric pre-alignment shape between two adjacent plates.

[0087] Preferably, as shown in FIG. 4, each flow field plate 10 occupies a thickness E10 in the stack 2, measured parallel to the stacking direction Z2. E10 is the thickness occupied by the periphery 3 of the flow field plate 10. Preferably, each flow field plate 30 occupies a thickness E30 in the stack 2, measured parallel to the stacking direction Z2. E30 is the thickness occupied by the periphery 3 of the flow field plate 30. Preferably, each membrane-electrode plate 50 occupies a thickness E50 in the stack 2, measured parallel to the stacking direction Z2. E50 is the thickness occupied by the periphery 3 of the membrane-electrode plate 50. Preferably, thicknesses E10 and E30 are greater than thickness E50 so that plates E10 and E30 can provide sufficient internal volume for the flow field channels in the direction of stacking direction Z2. Furthermore, thickness E10 is advantageously greater than thickness E30. For example, thickness E10 is at least 1.5 times greater than thickness E30, or even 2 times greater. This difference between thicknesses E10 and E30, in combination with the positioning and / or relative size of notches 12 and 32 described above, makes it possible to reduce the risk of a short circuit between adjacent flow field plates 10 and 30 and that same membrane-electrode plate 50. Indeed, in groove 6, due to the presence of the insulated and protruding notch 52, as well as the recess of notch 12 and the thickness of plate 10, the distance to be traversed for the formation of an electric arc connecting notch 12 to notch 32 located beyond membrane-electrode plate 50 is particularly large.

[0088] Preferably, for at least one of the peripheral seals 80, if not for all of them, the replacement edge portion 81 is flush in the direction Y2 with the replacement edge 11 or 31 of the plate 10 or 30 on which the seal 80 is formed. Alternatively, the replacement edge portion 81 can be slightly recessed in the opposite direction to the direction Y2 relative to the replacement edge 11 or 31 of the plate 10 or 30 on which the seal 80 is formed, or slightly protrude in the direction Y2. Preferably, for at least one of the seals 80, if not for all of them, the replacement edge portion 81 is recessed in the opposite direction to the direction Y2 relative to the replacement edge 51 of the plate 50 on which the seal 80 is formed. In other words, the edge 51 advantageously protrudes in the direction Y2 relative to the portion 81.

[0089] Preferably, for at least one of the peripheral seals 80, if not all of the peripheral seals 80, the secondary edge portion 83 is flush in the direction Y2 with the secondary edge 13 or 33 of the plate 10 or 30 on which the seal 80 is formed. Alternatively, the secondary edge portion 83 can be slightly recessed in the opposite direction Y2 relative to the secondary edge 13 or 33 of the plate 10 or 30 on which the seal 80 is formed, or slightly protrude in the direction Y2. Preferably, for at least one of the seals 80, if not all of the seals 80, the secondary edge portion 83 is recessed in the opposite direction Y2 relative to the secondary edge 53 of the plate 50 on which the seal 80 is formed. In other words, the edge 53 advantageously protrudes in the direction Y2 relative to the portion 83.

[0090] Preferably, for at least one of the peripheral seals 80 interposed between the plates 10 and 50, if not for all these seals 80 interposed between the plates 10 and 50, the recessed portion 82 is flush in the direction Y2 with the notch 12 of this plate 10 in which the seal 80 is formed. Preferably, this same recessed portion 82 is recessed in the direction Y2 relative to the notch 52 of the plate 50 in which the seal 80 is formed. This may mean that the size of the recessed portion 82 is larger than the size of the notch 52. Thus, during manufacturing, the recessed portion 82 can be traversed by the rail 131 without touching said recessed portion.

[0091] Preferably, for at least one of the peripheral seals 80 interposed between the plates 30 and 50, if not for all of these peripheral seals 80 interposed between the plates 30 and 50, the recessed portion 82 is recessed 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 mean that the size of the recessed portion 82 is larger than the size of the notches 32 and 52. Thus, during manufacture, the recessed portion 82 of the peripheral seal 80 can be traversed by the rail 131 without touching said recessed portion.

[0092] Preferably, for at least one of the end plates 70, and preferably for both plates 70, the replacement edges 71, secondary edges 73 and notches 72 are arranged in the same way as the replacement edges 31, secondary edges 33 and notches 32 of plate 30. In other words, except for the level of groove 8, the replacement edges 71, secondary edges 73 and notches 72 have the same shape and arrangement as those of plate 30. Preferably, the thickness of the plate measured at the periphery 3 of plate 70 parallel to thicknesses E10 and E30 is greater than thicknesses E10 and E30.

[0093] 2 and 6, longitudinal portion 91 of seal 90 adapts to and fills the shape of the different notches 12, 32, 52 and 72, as well as the recessed portion 82, in the opposite direction of direction Y2. In particular, notches 32 and 52, which protrude relative to one another, are advantageously enclosed by portion 91 of seal 90. In other words, seal 90 is received in and interposes notch 12 and recessed portion 82 at the level of notches 32 and 52, in direction Z2, between the respective peripheries 3 of consecutive plates 30 and 50. This arrangement not only ensures an optimal tightness of the fluid connection between manifold 100 and face 5, but also reduces the risk of electrical arcs in grooves 6.

[0094] Furthermore, the seal 90 projects in the direction Y2 beyond the exchange edges 11, 31, 51 and 71. Preferably, the seal 90 therefore projects over its entire periphery, i.e. relative to the sealing portions 91 and 92.

[0095] To manufacture the fuel cell 1, the process defined below can be carried out as shown in FIGS.

[0096] 7, the support plate 111 is preferably positioned in a horizontal plane so that the direction Z2 is vertical and oriented upward. Before the plates 10, 30, 50, and 70 and the seal 80 are stacked and before the seal 90 is formed, a peripheral centering template 130 including rails 131 is temporarily installed. Here, only two rails 131 are provided on the template 130, but a different number can be provided, with a corresponding number of centering grooves 6 on the plates 10, 30, 50, and 70. The template 130 also includes a fastening base 132 to which the rails 131 are fixedly attached.

[0097] The centering template 130 is attached to the periphery of the stack 2, i.e., to the outside of the stack 2, against the side 4 of the stack 2 having the groove 6. To be fastened to the plate 111, the template 130 is attached by being moved parallel to the direction Y2 relative to the plate 111 until it comes into contact with the plate 111, or by a movement having at least a component in the direction Y2.

[0098] In order to be fastened to the plate 111, the base 132 is advantageously attached to the fastening edge 115 of the plate 111, i.e., advantageously, the same fastening edge 115 that will later be used to fasten the manifold 100. Preferably, the base 132 is fastened to the fastening edge 115 by means of a screw. A threaded hole made in the edge 115 can be used to screw in the template 130 and later in order to screw in the manifold 100.

[0099] When the template 130 is installed, the rails 131 protrude from the base 132 in the direction Z2 and are distributed in a plane perpendicular to the direction X2.

[0100] At this stage, additional peripheral centering templates can be provided, arranged opposite other side surfaces 4 of stack 2, if these have corresponding centering grooves. Internal centering means can eventually be provided in stack 2, such as rods parallel to direction Z2 and passing through stack 2 from the inside, from plate 111.

[0101] Once the template 130 is installed, the plates 10, 30, 50, and 70, as well as the seal 80, are stacked to form the stack 2, but the seal 90 is not yet formed. To perform the stacking, each plate slides parallel to the Z2 direction along the rail 131, and the corresponding centering notch of each plate receives the rail 131. In other words, the rail 131 functions to guide the plate via the corresponding centering notch. As mentioned above, preferably, some plates, such as plates 50 and 70, are stacked individually, while other plates, such as plates 10 and 30, are pre-assembled in pairs before stacking. Preferably, each seal 80 is pre-assembled with one of the plates, preferably one of plates 10 and 30, before being added to the stack 2. In practice, a complete bipolar plate is added to the stack 2, including two adjacent pre-assembled plates 10 and 30 and two seals 80 formed on the plates 10 and 30, respectively, except possibly at the ends of the stack 2.

[0102] For each plate, or for each pre-assembled set comprising several plates, at least one of the centering notches mechanically cooperates with the rail 131 to guide sliding in direction Z2 and center this pre-assembled set or plates in directions X2 and Y2, while other centering notches recessed relative to the rail 131 in direction Y2 are crossed only by the rail 131 in direction Z2. In this example, only the centering notches 32, 52, and 72 of the secondary flow field plate 30, membrane-electrode plate 50, and end plate, respectively, are centering notches with contact that mechanically cooperates with the rail 131, while the notch 12 and recessed portion 82 of the primary flow field plate 10 and peripheral seal 80, respectively, are more recessed, at a distance from the rail 131, and are crossed only by the rail 131 in direction Z2 and are therefore non-contacting centering notches. Cooperation of the rails 131 with the centering notches ensures that when the stack 2 is completed, each plate of the stack 2 is correctly positioned relative to its adjacent plates, particularly in the directions X2 and Y2.

[0103] To perform the lamination, one begins by laminating the end plate 70 against the support plate 111, advantageously by sliding the end plate 70 along the rails 131 via the notches 72, as shown in Figure 7. The current manifold and planar seal, not shown, are then advantageously laminated.

[0104] The flow field plates 30 are then stacked, guiding the plates 30 in direction Z2 by cooperation of the rails 131 with the notches 32 until the plates 50 abut against the already assembled elements in the opposite direction Z2.

[0105] Next, one of the plates 50 is stacked, and the rails 131 cooperate with the notches 52 to guide the plate 50 in direction Z2 until it abuts against the already assembled flow field plate 30. A pre-assembled bipolar set is then stacked, including a plate 10 carrying a seal 80 facing the already stacked plate 50, a plate 30 fastened to the plate 10 in direction Z2, and a second seal 80 formed on the plate 30 in direction Z2. This pre-assembled set is guided by the rails 131, which cooperate with the notches 32. Another plate 50 is then stacked, and so on, alternating between pre-assembled bipolar sets and plates 50. Once the last plate 50 is stacked, another flow field plate 10 is added, and another current manifold and possible sealing seal are stacked on top of it. Next, a second end plate 70 is stacked.

[0106] The stack 2 is now complete and remains centered with the rail 131 still in place.

[0107] Once stack 2 is complete, and before seal 90 is in place, tie rod 113 is installed on support plate 111. Spring 114 and support plate 112 are then installed so that spring 114 is between support plate 112 and plate 70 at the top of stack 2 in direction Z2. Installing support plate 112 preferably involves threading support plate 112 onto tie rod 113.

[0108] Preferably, the support plate 112 carries a fastening base 134 which is fastened by screwing onto the fastening edge 116 of the support plate 112, preferably in a similar manner to the fastening base 132 fastened onto the fastening edge 115 of the support plate 111. The base 134, which belongs to the template 130 and is initially separated from it, is screwed onto the rails 131 and is configured to be guided by the rails by sliding in direction Z2. To install the support plate 112, the plate is advantageously screwed onto the tie rods 113, which screw the base 134 onto the rails 131, preferably in direction Z2, interposing the springs 114 between the plate 112 and the plate 70 at the top of the stack 2.

[0109] Once the stack 2 is placed between the two support plates 111 and 112, and while the template 130, particularly the rails 131, are still in place, the stack 2 is compressed using the tie rods 113, for example by tightening the nuts on the ends of the tie rods 113 to bring the support plates 111 and 112 closer together in direction Z2. Press fitting followed by torquing of the tie rod nuts is also possible.

[0110] Once the stack 2 is compressed between the plates 111 and 112, and before forming the seal 90, the rail 131 is removed, for example by removing the template 130 as a whole. For this purpose, the bases 132 and 134 are advantageously cut away from the plates 111 and 112 to separate the rail 131 from the plates 111 and 112. The template 130 is then moved away from the stack 2 transversely to the direction Z2, i.e., along a movement that includes a component in the direction Y2 relative to the stack 2. In particular, the rail 131 is pulled out of the centering groove 6 by being moved transversely to the direction Z2, in particular in the direction Y2 relative to the stack 2. Removal of the rail 131 is therefore particularly easy. The configuration of FIG. 3 is then achieved.

[0111] Once rail 131 is removed, manifold seal 90 is left in place, particularly with portion 91 in groove 6 and portion 92 in groove 8. Preferably, seal 90 is formed in situ by pouring, injecting, or overmolding seal 90 in a liquid or pasty state into grooves 6 and 8 and then allowing seal 90 to harden. To form seal 90 while it is in a liquid or pasty state, cell 1 is preferably oriented such that direction Y2 is directed upward, so that gravity contributes to the liquid or pasty material being received within grooves 6 and 8 without overflowing and conforming to the inner contours of grooves 6 and 8.

[0112] To form the seal 90, a first bead 95 of a first material, preferably in a liquid or pasty state, is first applied to grooves 6 and 8 around the entire periphery of the future seal 90, as shown in FIG. 6 . The first material, preferably a silicone-based or another suitable elastomer, remains in a liquid or pasty state without crosslinking during application, thus conforming to the bottoms of grooves 6 and 8 and, in particular, encapsulating the protruding notches 32 and 52. The low-viscosity material is advantageously selected to impart self-leveling and / or filling properties to the material. This ensures that the material conforms to the irregularities of grooves 6 and 8, particularly the bottom of groove 6, due to the fact that some centering notches are protruding and others are recessed. Despite its low viscosity, the material can be applied very precisely, thereby preventing it from spreading in the X2 direction by groove 6 and in the Z2 direction by groove 8.

[0113] Once the first bead 95 is applied, it is cured in place. In the case of silicone, curing can be achieved, for example, by cross-linking the silicone at room temperature. The first bead 95 then forms the base of the future seal 90, filling and fitting into grooves 6 and 8 around the entire circumference of the seal 90.

[0114] Once the first bead 95 is applied, a second bead 96 of a second material in a liquid or paste-like state is applied over the first bead 95. The second bead 96 can be applied while the first bead 95 is only partially cured to ensure good cohesion between the beads 95 and 96. The second bead 96 covers the first bead around the entire circumference of the seal 90 formed by the beads 95 and 96. The second bead 96 is formed around the entire circumference of the seal 90 so as to protrude relative to the grooves 6 and 8.

[0115] The second bead 96 is advantageously made of a second material that differs from the first material in at least its viscosity, as compared when the materials are in their uncured state. Advantageously, the second material for forming the second bead 96 is selected to be more viscous in its liquid or pasty state than the first material for forming the first bead 95 when the first material is itself in its liquid or pasty state. This advantageously allows the second bead 96, applied in its liquid or pasty state, to retain its raised shape above the first bead 95, even when the second material is not yet cured. This advantageously allows the second bead 96, and in general the seal 90, to be formed without a mold. Preferably, the second material is also silicone-based or another suitable elastomer. Once applied, the second bead 96 is cured in situ, for example by cross-linking the silicone at room temperature. This results in the configuration shown in FIG. 2.

[0116] Although the above process for forming the seal 90 is preferred, it is alternatively possible to form the seal 90 with a single injection of material, or to form the seal 90 using any other suitable process.

[0117] Once the seal 90 is formed, the fluid connection of the outer manifold 100 with the exchange surface 5 is made. For this purpose, the manifold 100, and in particular the connector 101, is abutted against the exchange surface 5, with the connector 101 approaching the manifold 100 parallel to the direction Y2. At least, the approaching movement of the connector 101 has a component in the direction Y2. The connector 101 is matched with the seal 90 so that the connector 101 is in sealing contact with the seal 90 around its entire periphery. In particular, the manifold 100 is supported in a leak-tight manner on the seal 90 via the bead 96. When the manifold 100 is abutted against the exchange surface 5, advantageously, the seal 90 has already hardened, or has already been cross-linked, or at least is no longer tacky, so that the manifold 100 does not adhere to the seal 90 but simply makes sealing contact with it.

[0118] Finally, outer manifold 100 is fastened using fastening system 102, specifically by screwing base 103 to fastening edge 115 and fastening base 104 to fastening edge 116. This results in the configuration of FIG.

[0119] Any feature described above with respect to one of the embodiments or variants may, where technically possible, be implemented with respect to any other of the embodiments or variants described above.

Claims

1. 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), stacked along a stacking direction (Z2) to form an electrochemical cell, each plate (10, 30, 50, 70) being oriented perpendicular to the stacking direction (Z2) and arranged flat with respect to the adjacent plates (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 one another and together forming an exchange surface (5) belonging to the stack (2), the exchange surface (5) extending parallel to the stacking direction (Z2); an outer manifold (100) attached to the stack (2) so as to cover the exchange surface (5) for exchanging a working fluid between the outer manifold (100) and the stack (2) via the exchange surface (5); and a manifold seal (90) surrounding the exchange surface (5) and interposed between the stack (2) and the outer manifold (100) to ensure a fluid-tight connection between the outer manifold (100) and the stack (2); a fastening system (102) separate from the manifold seal (90), the outer manifold (100) being fastened to the stack (2) via the fastening system (102); A fuel cell (1) comprising: each plate (10, 30, 50, 70) comprises a respective centering notch (12, 32, 52, 72) adjacent to said exchange edge (11, 31, 51, 71), said centering notches (12, 32, 52, 72) together forming a centering groove (6) belonging to said stack (2), said centering groove (6) extending parallel to said stacking direction (Z2) in contact with said exchange surface (5); The manifold seal (90) comprises a longitudinal seal portion (91) that is parallel to the stacking direction (Z2) and formed in the centering groove (6) so that the longitudinal seal portion (91) is interposed between the stack (2) and the outer manifold (100) to ensure a fluid-tight connection between the outer manifold (100) and the stack (2).

2. 2. The fuel cell (1) according to claim 1, wherein at least one of the flow field plates (10, 30) has exchange openings (19) formed in the exchange edges (11, 31) of the flow field plates (10, 30) that open onto the surface of the exchange face (5) and are covered by the outer manifold (100), and the exchange of working fluid between the outer manifold (100) and the stack (2) is carried out via the exchange openings (19).

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

4. 4. The 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) protrudes outward from the stack (2) relative to the secondary edge (13, 33, 53, 73).

5. 5. The fuel cell (1) according to claim 3, wherein for at least one of the membrane-electrode plates (50), the secondary edge (53) of the membrane-electrode plate (50) projects outward from the stack (2) relative to the secondary edge (13, 33) of the adjacent flow field plate (10, 30).

6. The flow field plates (10, 30) comprise a primary flow field plate (10) and a secondary flow field plate (30); at least one of the primary flow field plates (10) is adjacent to one of the secondary flow field plates (30) to form, together with the secondary flow field plate (30), a bipolar plate; 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 flush with each other; 10. The fuel cell (1) of claim 1, wherein the centering notches (12) of the primary flow field plates (10) are recessed inward from the stack (2) relative to the centering notches (32) of the secondary flow field plates (30).

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

8. 10. The 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) protrudes outward from the stack (2) relative to the exchange edge (11, 31) of the adjacent flow field plate (10, 30).

9. 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), and each peripheral seal (80) an exchange edge portion (81) interposed along the stacking direction (Z2) between the exchange edge portion (11, 31) of the flow field plate (10, 30) and the exchange edge portion (51) of the membrane-electrode plate (50), the exchange edge portion (81) being flush with the exchange edge portion (11, 31) of the flow field plate (10, 30) or being recessed inward from the stack (2) relative to the exchange edge portion (11, 31) of the flow field plate (10, 30); a recessed portion (82) interposed along the stacking direction (Z2) between the centering notch (12, 32) of the flow field plate (10, 30) and the centering notch (52) of the membrane-electrode plate (50), the recessed portion (82) being recessed inward from the stack (2) relative to the centering notch (52) of the membrane-electrode plate (50) and being flush with or recessed inward from the stack (2) relative to the centering notch (12, 32) of the flow field plate (10, 30); 10. The fuel cell (1) according to any one of the preceding claims, comprising:

10. 10. The fuel cell (1) according to claim 1, 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 when projected on a projection plane (P2) perpendicular to the stacking direction (Z2).

11. The plates (10, 30, 50, 70) of the stack (2) include an end plate (70) that terminates the stack (2) along the stacking direction (Z2), a transverse groove (8) is provided 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); 10. The fuel cell (1) according to claim 1, wherein the manifold seal (90) comprises a transverse seal portion (92) perpendicular to the stacking direction (Z2), formed in the transverse groove (8), and coupled to the longitudinal seal portion (91), whereby the transverse seal portion (92) is interposed between the end plate (70) and the outer manifold (100) to ensure a fluid-tight connection between the outer manifold (100) and the stack (2).

12. A method for manufacturing a fuel cell (1) according to any one of the preceding claims, comprising: installing a centering rail (131) parallel to the stacking direction (Z2) and receivable in the respective centering notches (12, 32, 52, 72) of the plates (10, 30, 50, 70) while the plates (10, 30, 50, 70) of the stack (2) have not yet been stacked and the manifold seal (90) has not yet been formed; successively stacking the plates (10, 30, 50, 70) to form the stack (2) while the centering rail (131) is installed, the centering rail (131) guiding the plates (10, 30, 50, 70) by mechanically cooperating with at least one of the centering notches (12, 32, 52, 72) with the centering rail (131) to ensure centering of the plates (10, 30, 50, 70) transverse to the stacking direction (Z2); After the stack (2) is completed, removing the centering rail (131) by moving the centering rail (131) laterally relative to the stacking direction (Z2) so as to move it away from the stack (2); After the stack (2) is completed and the centering rail (131) is removed, placing the manifold seal (90) with the longitudinal seal portion (91) formed in the centering groove (6); fluidly connecting the outer manifold (100) to the stack (2) after the manifold seal (90) has been positioned by interposing the manifold seal (90) including the longitudinal seal portion (91) between the stack (2) and the outer manifold (100) and abutting the outer manifold (100) against the stack (2) so as to cover the exchange surface (5) to ensure a fluid-tight connection between the outer manifold (100) and the stack (2); fastening the outer manifold (100) to the stack (2) using the fastening system (102); A method comprising:

13. The step of installing the centering rail (131) includes fastening the centering rail (131) to a support plate (111) belonging to the fuel cell (1); said successively stacking said plates (10, 30, 50, 70) comprises stacking one of said plates (10, 30, 50, 70) against said support plate (111) parallel to said stacking direction (Z2); The method of claim 12, wherein the removing the centering rail (131) comprises separating the centering rail (131) from the support plate (111).

14. said positioning said manifold seal (90) applying a first bead (95) of elastomer in a non-crosslinked state in said centering groove (6) to form said longitudinal sealing portion (91); after the first bead (95) is applied, in-situ crosslinking the uncrosslinked elastomer of the first bead (95); 14. The method of claim 12 or claim 13, comprising:

15. 15. The method of claim 14, wherein positioning the manifold seal further comprises applying a second bead of elastomer in a non-crosslinked state on the first bead so that the second bead protrudes outward from the stack toward the exchange surface after the first bead is applied, the elastomer of the second bead having a higher viscosity when the second bead is applied than a viscosity of the elastomer of the first bead when the first bead is applied.

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