Single fuel cell and related fuel cells

Abstract

The present invention relates to a single cell (100) of a fuel cell stack, comprising a plurality of walls (102), each of which is continuous and sealed, defining a single-cell compartment (V100), and which are held together by a sealing structure (200). The sealing structure is formed from a stack of wall frames (220), each of which surrounds an associated wall (102), compartment frames (230), each of which is disposed around a corresponding compartment (V100), and adhesive layers (240) inserted between each of the frames of the sealing structure to sealingly secure the frames to one another. Each wall forms a peripheral gap with its associated wall frame, which is sealingly closed on at least one of its faces by a compartment frame disposed opposite the peripheral gap.

Description

[Technical Field]

[0001] The present invention relates to a single cell of a fuel cell, as well as to a fuel cell comprising such a single cell. [Background technology]

[0002] A fuel cell is a device that generates electricity through an electrochemical reaction between a fuel, such as dihydrogen (also simply called hydrogen), and an oxidant, such as dioxygen (also simply called oxygen), found in air. Here, we are interested in proton exchange membrane fuel cells (also called PEMFCs) with a solid electrolyte, which typically comprise a stack of single cells, each forming an electrochemical generator.

[0003] Schematically, each single cell includes two separators, also called bipolar plates, between which is interposed a solid electrolyte in the form of a proton exchange membrane. The membranes are made, for example, of perfluorinated sulfonated polymer materials. Within each cell, each separator defines a reaction compartment with a corresponding membrane. One of the two reaction compartments houses a cathode element, while the other reaction compartment houses an anode element.

[0004] In a stack, cells are stacked with alternating cathode and anode elements. In many types of fuel cells, for two adjacent cells, the separator of one cell is back-to-back with the separator of the other cell. The two separators together form a bipolar separator, also called a bipolar plate. A cooling compartment, through which a cooling fluid such as glycolated water circulates, is typically located between the two separators of the bipolar separator. In other types of fuel cells, particularly those without liquid cooling, the same separator is shared by two adjacent cells, and therefore the cell does not include a cooling compartment.

[0005] Hydrogen, air, and any coolant are so-called "working fluids" that are supplied to the fuel cell during its operation. Depending on the fuel cell's operating stage, the supply of one or more working fluids may be continuous or intermittent.

[0006] The fuel cell thereby provides a fluid supply to each of the reaction compartments and an opening for supplying the fluid between two adjacent cells, such that each bipolar separator provides a fuel supply on one side to the cells adjacent to said side and an oxidant supply on the other side to the cells adjacent to the other side, the supplies provided by the bipolar separators being parallel.

[0007] When a fuel cell is in operation, the electrochemical reactions generate a potential difference between the two separators of each single cell, which makes the fuel cell equipped with an electrical insulating device designed to prevent leakage of electrical current between two adjacent cells and between each cell and the external environment, and a sealing device to prevent leakage of the working fluid, in particular to prevent the fluid circulating in one reaction compartment from contaminating the adjacent reaction compartment.

[0008] EP 3618157, for example, describes a redox cell whose fuel and oxidant are electrolytes, i.e., liquids. The redox cell includes a frame made of polypropylene and positioned around the bipolar plates and electrodes to reduce current leakage. The frame is perforated to provide circulation channels for the electrolyte. Sealing is provided by an O-ring placed in a groove machined into the thickness of the frame and held in compression by a clamping flange. Such a structure is not suitable for the passage of gaseous fluids, particularly air or hydrogen, used with fuel cells. Furthermore, installing and verifying each seal is a tedious task.

[0009] Japanese Patent No. 5330135 describes a single fuel cell having a sealing structure composed of a frame and an L-shaped separator, which are assembled by laminating the frame and the separator with adhesive elements. The passage between the manifold and the inner compartment of the single cell is recessed in the L-shaped separator, which requires a specific machining process and complicates the assembly of the sealing structure. Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention aims to address the above problems more particularly by proposing a fuel cell stack that is easy to assemble, providing both good electrical insulation and good sealing. [Means for solving the problem]

[0011] To this end, the present invention relates to a single cell of a fuel cell stack, the single cell comprises a plurality of walls, each of which is continuous and sealed and stacked together along a stacking axis, the walls defining a compartment of the single cell; a first separator; a second separator; a proton exchange membrane interposed between the first separator and the second separator; Including, the first separator defines, with the membrane, a first reaction compartment configured to receive a first working fluid of the fuel cell; the second separator defines, with the membrane, a second reaction compartment configured to receive a second working fluid of the fuel cell; the compartments of the single cell include the first reaction compartment and the second reaction compartment; The cell further comprises a sealing structure, the sealing structures comprising frames each made of a polymer material and stacked along the stacking axis, the frames being disposed around the walls and the compartments.

[0012] According to the invention, for at least one of the compartments of the single cell and for at least one of the two walls defining the at least one compartment: The frame of the sealing structure is wall frames coplanar with and surrounding a corresponding wall, the inner edge of each wall frame being positioned opposite the outer edge of said wall, the inner edge of the wall frame and the outer edge of the wall being opposite each other and separated by a peripheral gap, each wall frame preferentially having a thickness substantially equal to the thickness of the corresponding wall; a compartment frame disposed around the corresponding compartment, the compartment frame having an inner edge oriented toward the corresponding compartment and defining the compartment in a radial direction relative to the stacking axis, and an outer edge opposite the inner edge, the inner edge having an inner contour, while the outer edge having an outer contour; an adhesive layer interposed between the compartment frame on the one hand and the wall and wall frame adjacent to the compartment frame on the other hand, respectively, so as to attach the frames together in a sealed manner; Including, an inner contour of the compartment frame is included in an outer contour of the wall in projection along the stacking axis, whereby an annular portion of the wall faces a mating portion of the compartment frame along the stacking axis, forming a first overlap of the compartment frame on the wall; the inner contour of the wall frame is included in the outer contour of the compartment frame in projection along the stacking axis, whereby the annular portion of the wall frame faces the mating portion of the compartment frame, forming a second overlap of the compartment frame on the wall frame; the adhesive layer includes a first portion of the layer extending opposite the first overlap between the compartment frame and the adjacent wall to sealingly attach the compartment frame to the wall; The adhesive layer includes a second portion of the layer extending opposite the second overlap between the compartment frame and the adjacent wall frame to sealingly attach the compartment frame to the wall frame.

[0013] According to the present invention, the frames of the sealing structure are assembled together using an adhesive layer, making the assembly of a single cell practical and quick to manufacture. Furthermore, because the first compartment frame has an internal contour that is contained within the external contour of the membrane, a first portion of the adhesive layer interposed between the internal surface of the first compartment frame and the external surface of the adjacent membrane prevents leakage of the working fluid circulating in the first reaction compartment toward the second reaction compartment. Similarly, because the internal contour of the first compartment frame is contained within the external contour of the first separator, a second portion of the adhesive layer interposed between the internal surface of the first compartment frame and the external surface of the adjacent separator prevents leakage toward the cooling compartment. The first and second portions of the adhesive layer provide a seal across their overlapping surfaces, preventing the passage of both liquid and gaseous working fluid between the elements assembled by the adhesive layer. Furthermore, repositionable and / or pressure-sensitive adhesive layers can be used, making it possible to propose removable cells.

[0014] According to advantageous but non-essential aspects of the invention, such a single cell may incorporate one or more of the following features taken individually or in any technically permissible combination:

[0015] A first separator is configured to sealingly separate the first reaction compartment from a first cooling compartment configured to receive a third working fluid of the fuel cell, while the single cell compartment includes the first cooling compartment in addition to the first reaction compartment and the second reaction compartment.

[0016] The first portion of the adhesive layer and the second portion of the adhesive layer l are part of the same adhesive layer that extends continuously across one face of the compartment frame to seal the peripheral gap adjacent to the compartment frame.

[0017] The first overlap has a leakage length equal to the smallest distance measured parallel to the central plane between any two points belonging to the inner edge of the corresponding compartment frame and the outer edge of the adjacent corresponding wall, while the second overlap has a leakage length equal to the smallest distance measured parallel to the central plane between any two points belonging to the outer edge of the corresponding compartment frame and the inner edge of the adjacent corresponding wall frame, each leakage length being 1 mm or more, preferably 2 mm or more, otherwise preferably 3 mm or more.

[0018] For at least one of the compartment frames: the compartment frame includes a transfer frame providing two passages for fluids, the two passages intended for the circulation of the associated working fluid between the corresponding compartment and the outside of the single cell; each passageway opening into an associated compartment through an internal port provided in an inner edge of the transfer frame; Each passageway opens to the outside of the compartment through an external port.

[0019] Each passage includes an interior portion that opens into the compartment through the interior port, the interior portions of the passage being disposed within the thickness of the transfer frame.

[0020] The external port is located on the outer edge of the transfer frame.

[0021] For at least one transport frame, At least one of the two passages contains guide fins for the associated working fluid; the fins are formed by cutting the transfer frame and are spaced apart within corresponding passages to direct the flow of associated working fluid; The fins are held by the adhesive layer with a corresponding transfer frame interposed therebetween.

[0022] For at least one of the first and second reaction compartments, the compartment frame comprises: the transfer frame; a first sealing frame interposed between the transfer frame on the one hand and a first wall of the two walls adjacent to the partition frame and a wall frame opposite the first wall on the other hand; a first adhesive film interposed between the first sealing frame and the transfer frame, the first sealing frame being attached to the first wall and the opposing wall frame by an adhesive layer associated with the first wall on the one hand, and fixed to the transfer frame by the first adhesive film on the other hand; Equipped with.

[0023] The compartment frame includes, in addition to the first sealing frame: a second sealing frame, the first and second sealing frames being arranged on both sides of the transfer frame, the second sealing frame being interposed between the transfer frame on the one hand and a second wall of the two walls adjacent to the compartment frame and a wall frame associated with this second wall on the other hand, the second wall being different from the first wall; a second adhesive film interposed between the second sealing frame and the transfer frame; Equipped with The second sealing frame is attached to the second wall and the opposing wall frame by corresponding adhesive layers on the one hand, and to the transfer frame by a second adhesive film on the other hand.

[0024] For at least one sealing frame, the adhesive film associated with the sealing frame is coated continuously on one side of the sealing frame.

[0025] For at least one sealing frame, said sealing frame is made of a polymer material, for example PET, and has a thickness, measured parallel to the stacking axis, comprised between 10 μm and 20 μm, preferably equal to 12 μm; The adhesive film interposed between the sealing frame and the corresponding transfer frame has a thickness, measured parallel to the lamination axis, comprised between 6 μm and 30 μm, preferably comprised between 8 μm and 20 μm, preferably comprised between 10 μm and 15 μm.

[0026] For each compartment of the single cell and for each of the walls defining the compartment, the peripheral gap associated with the wall is sealed on at least one of the faces of the wall by a sealing frame.

[0027] For at least one transport frame, the transfer frame is made of a polymer material, for example PET, and has a thickness, measured parallel to the stacking axis, comprised between 50 μm and 200 μm, preferably comprised between 80 μm and 150 μm, preferably equal to 100 μm, Each of the first portions of the adhesive layer and each of the second portions of the adhesive layer have a thickness, measured parallel to the lamination axis, between 15 μm and 30 μm, preferably between 18 μm and 25 μm, preferably equal to 20 μm.

[0028] The invention further relates to a fuel cell comprising a stack formed from a plurality of individual cells stacked along a stacking axis, each individual cell being as defined in any of the preceding claims, and a sleeve providing an internal volume in which the stack is housed, the frames of each single-cell sealing structure each having a unique outer edge with an associated outer contour; the outer contours of all frames of each sealing structure are superimposed on one another along the stacking axis, and the outer edges of all frames of all the sealing structures together form an outer surface of the stack having a cylindrical shape centered on the stacking axis; an outer surface of the stack provides a retaining member configured to cooperate with a fitting provided within the internal volume of the sleeve to maintain the stack within the internal volume and provide an ambient volume between the stack and the sleeve; The retaining member and the fitting member are designed to divide the surrounding volume into a plurality of circulation conduits for the working fluid of the fuel cell.

[0029] Advantageously, for each compartment of each single cell, the associated compartment frame comprises a transfer frame providing two passages for fluid, the two passages intended for the circulation of the associated working fluid between the corresponding compartment and the outside of said single cell; Each passageway opens into the associated compartment through an internal port provided in the inner edge of the transfer frame; Each passageway opens to the outside of the compartment through an external port.

[0030] The external port is provided on an outer edge of the transfer frame, while the fuel cell provides two first pairs of circulation conduits respectively associated with a first working fluid and a second working fluid of the fuel cell, the single cell being as defined above; For each single cell, Each of two compartments selected from the first reaction compartment and the second reaction compartment is associated with a respective pair of first conduits; The compartment frames associated with each of the two reaction compartments of the single cell each include a transfer frame having two passages, and the external port of each passage is provided at the outer edge of the corresponding transfer frame; Two passages of the same transfer frame each open into a different one of the two circulation conduits of the associated pair.

[0031] For each single cell, a first separator is configured to sealingly separate the first reaction compartment from a first cooling compartment configured to receive a third working fluid of the fuel cell; Meanwhile, the fuel cell provides, in addition to the two first pairs of circulation conduits, a third pair of circulation conduits, the third pair of circulation conduits being associated with the third working fluid; On the other hand, for each single cell, each of three compartments selected from the first reaction compartment, the second reaction compartment, and the first cooling compartment is associated with a respective pair of three pairs of conduits; The compartment frames associated with each of the three reaction compartments of the single cell each include a transfer frame having two passages, and the external port of each passage is provided at the outer edge of the corresponding transfer frame; Two passages of the same transfer frame each open into a different one of the two circulation conduits of the associated pair.

[0032] The present invention will be better understood and other advantages will become more apparent in the light of the following description of embodiments of single cells and fuel cells in accordance with its principles, given by way of example only and with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0033] [Figure 1] FIG. 1 is a perspective view of a fuel cell according to the present invention. [Figure 2] FIG. 2 shows two schematic views of the fuel cell shown in FIG. 1, viewed in a partially exploded perspective view and a top view in the two insets a) and b), with some parts hidden. [Figure 3] FIG. 3 shows in two insets a) and b) respectively a sleeve and a single cell of the fuel cell shown in FIG. 1, the single cell being according to one embodiment. [Figure 4] FIG. 4 is an exploded perspective view of a single cell shown in FIG. 3, with some parts hidden. [Figure 5] FIG. 5 is a partially exploded perspective view of the first compartment of a single cell of FIG. 3, observed at two different scales in the two insets a) and b) and in cross section in the inset b). [Figure 6] FIG. 6 is a partially exploded perspective view of a single cell according to another embodiment, viewed at two different scales in two insets a) and b) and in cross section in inset b). [Figure 7]FIG. 7 is an exploded partial perspective view of a single cell according to another embodiment. [Figure 8] FIG. 8 is a partially exploded perspective view of the second compartment of the single cell shown in FIG. [Figure 9] FIG. 9 shows, in two insets a) and b), respectively, a partially exploded perspective view of a single cell according to two other embodiments of the invention. [Figure 10] FIG. 10 is a schematic diagram of a partial cross section of one embodiment of a single cell shown in FIG. [Figure 11] FIG. 11 is a schematic diagram of a partial cross section of a single cell according to another embodiment. [Figure 12] 12 is a perspective view of a first cleaning spacer of the single cell shown in FIG. 3. FIG. [Figure 13] Figure 13 correspondingly shows, in three insets a), b) and c), detail XIIIa of the cleaning spacer shown in Figure 12, which detail is observed in an exploded perspective view and illustrates the operating principle of the cleaning spacer shown in Figure 12. [Figure 14] 14 is a perspective view of a second cleaning spacer of the single cell shown in FIG. 3. FIG. [Figure 15] FIG. 15 is an exploded perspective view on a larger scale of detail XV of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0034] A fuel cell 20 is shown in FIG. 1. The fuel cell 20, hereinafter also referred to simply as "cell 20," comprises a housing 22 including a sleeve 24. The sleeve 24 extends along a cell axis A20 and has the shape of a hollow cylinder with a substantially rectangular cross section herein. The sleeve 24 provides an interior volume V24 with two opposing openings, which are closed by two covers 26A and 26B. The sleeve 24 and covers 26A and 26B are preferably made of an electrically insulating material, such as a polymer material or a fiber-reinforced polymer material, or are coated, at least on their inner surfaces, with an electrically insulating material.

[0035] Fluid conduits are provided through housing 22 for carrying working fluid for cell 20. The working fluids herein include three fluids, thus two gaseous fluids, herein air and dihydrogen, and a dielectric heat transfer fluid, such as a liquid, herein glycolated water. The fluid conduits are embodied by fluid couplings provided herein on cover 26A, located at the top of FIGS. 1 and 2. Alternatively, all or a portion of the fluid couplings are provided on cover 26B. Alternatively, all or a portion of the fluid couplings are located on sleeve 24.

[0036] The cell 20 thereby comprises three pairs of fluid couplings, each pair intended for the circulation of a particular working fluid. The three pairs of fluid couplings include a first pair of couplings 28A, a second pair of couplings 28B, and a third pair of couplings 28C. For each pair of couplings, one of the couplings is called the "inlet coupling" and intended for the intake of the corresponding working fluid, while the other coupling is called the "outlet coupling" and intended for the extraction of the corresponding working fluid. In the figure, the direction of circulation of the working fluid is represented schematically by an arbitrarily oriented arrow, and it will be understood that the direction may in fact be other.

[0037] In Figure 2, cell 20 is shown schematically in an exploded perspective view with cover 26A separated from sleeve 24. Fittings 28A, 28B, and 28C are represented diagrammatically by openings through cover 26A. Sleeve 24 is shown in isolation in Figure 3a).

[0038] The internal volume V24 of the sleeve 24 accommodates the stack 50. The stack 50 has an outer surface S50 that has the shape of a cylinder with a generally rectangular cross section centered on a stack axis A50. When the stack 50 is received in the internal volume V24, the stack axis A50 coincides with the cell axis A20.

[0039] The stack 50 is formed from a plurality of individual cells 100 stacked along a stacking axis A50. The individual cells 100 are shown in isolation in FIG. 3b) and in an exploded perspective view in FIG. 4. Each individual cell 100 has a flat shape extending along a mid-plane P50 perpendicular to the stacking axis A50. In other words, the mid-plane P50 is a plane intersecting the stacking axis A50. Each individual cell 100, hereinafter simply referred to as a "cell 100," has an outer contour C100 when projected onto the mid-plane P50. It will be understood that the cross-section of the outer surface S50 of the stack 50 corresponds to the outer contour C100 of each individual cell 100.

[0040] The outer surface S50 of the stack 50 provides a retaining member 52 configured to cooperate with a complementary element 30 provided within the interior volume V24 of the sleeve 24 to maintain the stack 50 within the interior volume V24 and to provide a surrounding volume V50 between the stack 50 and the sleeve 24. The surrounding volume V50 is therefore a portion of the interior volume V24 that is distributed around the stack 50.

[0041] The retaining member 52 and the fitting member 30 are provided along the outer surface S50 parallel to the stack axis A50 and along the sleeve 24 parallel to the cell axis A20, respectively, and include sealing elements to divide the surrounding volume V50 into a plurality of circulation conduits for the working fluid of the fuel cell 20. Advantageously, the retaining member 52 and the fitting member 30 provide electrical insulation between the stack 50 and the sleeve 24.

[0042] Each circulation conduit is fluidly connected to a respective fitting 28 A, 28 B, or 28 C to ensure circulation of working fluid around the stack 50 and therefore around each single cell 100 .

[0043] Fuel cell 20 herein provides six circulation conduits associated in pairs corresponding to the fuel cell's three working fluids, such that the six circulation conduits include a first pair of conduits 38A fluidly connected to a first pair of fittings 28A, a second pair of conduits 38B fluidly connected to a second pair of fittings 28B, and a third pair of conduits 38C fluidly connected to a third pair of fittings 28C.

[0044] This results in each circulation conduit 38A, 38B, or 38C being sealed off from the adjacent conduits. As used herein, "sealed" means sealed off with respect to either the liquid or gaseous working fluid of the fuel cell 20, and in particular sealed off with respect to hydrogen, which is most prone to leakage compared to other working fluids due to its small molecular size and low viscosity.

[0045] Thus, in the example shown in more detail in FIGS. 1 and 3 , the sleeve 24 is the outer wall of the cell 20, defines the circulation conduits 38A, 38B, or 38C, and the fluid circulates under a pressure higher than atmospheric pressure. Even if such pressure is generally less than 5 bar absolute, or even less than 3 bar absolute, the pressure difference with atmospheric pressure prevailing outside the sleeve 24 must be taken into account, particularly to ensure that the sleeve 24 does not deform (especially by bulging) to the point of compromising the seal between the circulation conduits 38A, 38B, or 38C. In the example shown, external reinforcements are provided to limit deformation due to bulging, particularly of the largest surface of the sleeve 24. In this example, the external reinforcements are independent of the sleeve 24 and are therefore mounted directly on the sleeve 24 and attached to the outside of the sleeve 24, each abutting a surface (here, the flat outer surface) of the sleeve 24. Each external reinforcement extends along the cell axis A20 between its two ends. In this example, each end is attached to a corresponding cover 26A, 26B, for example, by screwing. Alternatively, the external stiffeners may be attached only to the sleeve 24, or may be attached to the sleeve 24 on one side and to only one of the two covers on the other side. Each external stiffener has a central body that abuts the corresponding outer surface of the sleeve 24. In the example shown, only two external stiffeners are provided, one on each of the two opposing sides of the sleeve 24 that have the largest surface and are therefore most at risk of deformation due to pressure in the circulation conduits 38A, 38B, or 38C. However, an external stiffener can also be provided for each outer surface, particularly each flat outer surface of the sleeve 24. In the example shown, the central body of the external stiffener has a lateral width, along a direction perpendicular to the cell axis A20 and parallel to the corresponding outer surface of the sleeve 24, that is preferably at least 50% of the lateral width of the corresponding outer surface against which the central body abuts, so that only one external stiffener is required for the corresponding outer surface. However, for a given outer surface of the sleeve 24, a plurality of separate individual reinforcements may be provided, offset from one another along the transverse direction, so that each has a smaller transverse width.In the illustrated example, the external stiffener, herein a stiffener integral with the central body, forms a thickened portion in the central body along a radial direction perpendicular to the cell axis A20 and perpendicular to the corresponding outer surface of the sleeve 24. Advantageously, the stiffener has a radial thickness along a radial direction that varies along the direction of the cell axis A20, with a smaller radial thickness at the two ends and, conversely, a larger radial thickness at the center of said direction. This allows the stiffness of the stiffener to be optimized by adapting its thickness to the constraints experienced by the sleeve 24 at different points due to the pressure inside the conduit. The directly attached external stiffener is preferably made of metal, such as aluminum or an aluminum alloy, for example in the form of a cast aluminum alloy part. In one variant, the directly attached external stiffener is made of a polymer material, preferably a composite material combining a polymer resin with a reinforcement, for example in the form of glass fiber, carbon fiber, and / or aramid fiber. According to yet another variant, similar reinforcements are incorporated into the sleeve 24, in other words made integral with the sleeve, thus giving the sleeve an optimized geometry for withstanding the forces resulting from the pressure of the fluid in the circulation conduits 38A, 38B or 38C.

[0046] The individual cells 100 of the stack 50 are preferably identical to one another. A detailed description of the individual cells 100 will now be given.

[0047] As shown in Figure 4, the cell 100 comprises a plurality of walls 102 that are continuous and sealed and stacked together along a stacking axis A50. These walls 102 include a first separator 110, a second separator 120, and a proton exchange membrane 130. The wall 102 formed by the membrane 130 is interposed between the first separator 110 and the second separator 120. The walls 102 define a compartment V100 of the single cell 100 therebetween.

[0048] Further in Figure 4, second separator 120 is represented schematically by a dotted line. First separator 110 and second separator 120 are preferably identical to each other and are manufactured herein by cutting a metal sheet, for example a stainless steel sheet.

[0049] The membrane 130, also called PEM for "Proton Exchange Membrane" (in English), is produced herein in the form of a polymer layer 130A. Generally, on both sides of the membrane 130, in each of the compartments V100 bounded by the membrane 130 on both sides, a gas diffusion layer 130B is provided, so that the membrane 130 is sandwiched between the two gas diffusion layers 130B. The polymer layer 130A is made herein, for example, of a fluorinated polymer material known under the trade name Nafion.

[0050] In the example shown, polymer layer 130A is coated on two sides with catalyst layers, and membrane 130 is called CCM (for "Catalyst Coated Membrane" in English). The catalyst layers are not shown. Membrane 130, gas diffusion layers 130A and 130B, and associated catalyst layers together form what is commonly called an MEA, an acronym for "Membrane Electrode Assembly" in English.

[0051] In an alternative not shown, at least one of the catalyst layers is deposited on one or the other of the two gas diffusion layers 130B, between the gas diffusion layer 130B and the adjacent polymer layer 130A.

[0052] The polymer layer 130A is sealed against reactive gases, hydrogen, or oxygen, but allows the diffusion of protons H+ therethrough. The gas diffusion layer 130B, also called GDL (in English), is porous to reactive gases and is made mostly of entangled and compressed carbon fibers. The gas diffusion layer 130B may, if appropriate, be coated on its side in contact with the membrane 130A with an ionomer, which may be of the same nature as the material of the polymer layer 130A. The structure of the membrane 130 will not be described in detail hereafter.

[0053] The membrane 130 has a first surface 132 and a second surface 134 opposite the first surface 132. The first surface 132 and the second surface 134 extend parallel to the central plane P50. The first surface 132 is oriented toward the first separator 110. The first separator 110 defines, via the membrane 130, a first reaction compartment V132 configured to receive a first working fluid of the fuel cell 20. In this specification, the first reaction compartment V132 is, for example, the anode compartment of a single cell 100, which means that the first working fluid is hydrogen. Thus, the first working fluid is a gaseous fluid. The first reaction compartment V132 is one of the compartments V100 of the cell 100.

[0054] The second surface 134 is oriented toward the second separator 120. The second separator 120 defines, by the membrane 130, a second reaction compartment V134 configured to receive a second working fluid of the fuel cell. In this specification, the second reaction compartment V134 is, for example, the cathode compartment of a single cell 100, which means that the working fluid circulating within the compartment is oxygen-containing air. The second working fluid is therefore a gaseous fluid. The second reaction compartment V134 is another of the compartments V100 of the cell 100.

[0055] It will be understood that when three single cells 100, including a bottom cell 100, a middle cell 100, and a top cell 100, are stacked on top of each other, the first separator 110 of the middle cell is adjacent to the second separator 120 of the top cell 100.

[0056] In the illustrated example, the first separator 110 of the middle cell 100 and the second separator 120 of the upper cell define a first cooling compartment V136 of the middle cell 100 therebetween.

[0057] Thus, the first cooling compartment V136 is common to two adjacent cells 100. The second separator 120 of the middle cell 100 and the first separator 110 of the bottom cell 100 define the second cooling compartment V138 of the middle cell therebetween. Thus, in the case of two stacked unitary cells 100, the first cooling compartment V136 of the bottom cell is the second compartment V138 for the top cell.

[0058] More generally, for the described cell 100, each cooling compartment V136 and V138 is configured to receive a third working fluid of the fuel cell 20. The third working fluid is herein a cooling fluid such as liquid glycolated water. Thus, the third working fluid is herein a liquid fluid at the operating temperature of the cell 20. More generally, the first separator 110 is configured to sealingly separate the first reaction compartment V132 from the first cooling compartment V136.

[0059] Thus, in the illustrated example, each single cell 100 includes three compartments V100: a first reaction compartment V132, a second reaction compartment V134, and a first cooling compartment V136. Each of the compartments V100 is associated with a corresponding working fluid of the fuel cell 20.

[0060] The fuel cell 20 here houses a cleaning spacer in each of the compartments V100 of the single cell 100. More precisely, the second reaction compartment V134 houses a first type of cleaning spacer 600 according to the first embodiment, while the first reaction compartment V132 houses a second type of cleaning spacer 700 according to another embodiment. The first cooling compartment V136 also houses another instance of the second type of spacer 700.

[0061] The washing spacers 600 or 700 are configured to define the circulation of the corresponding working fluid within each compartment V100. The washing spacers 600 and 700 are described further herein. When the cell 20 is assembled, the first separator 110, the second separator 120, the membrane 130, and the spacers 600 and 700 abut against each other. Preferably, the gas diffusion layer 130B is stacked by axial clamping between the washing spacers 600 or 700 and the corresponding surface of the membrane 130 along the stacking axis 150 to provide good electrical conduction between the stacked elements.

[0062] According to another embodiment, the unitary cell 100 further comprises a sealing structure 200 (FIG. 5). The sealing structure comprises frames 210, each made of a polymer material and stacked along a stacking axis A50. The frames 210 are disposed around the walls 102 of the unitary cell 100 and around the compartment V100.

[0063] The principle of the sealing structure 200 is explained using Figure 5, where two walls 102 of a single cell 100 defining a single compartment V100 are represented. The upper wall 102 in Figure 5a) is here a membrane 130, while the lower wall 102 in Figure 5a) is a second separator 120. The represented compartment is therefore a second reaction compartment V134, it being understood that the described principle can be transferred to other compartments V100 and corresponding walls 102 of a single cell 100.

[0064] The remainder of the single cell 100, in particular the cleaning spacer 600 or the diffusion layer 130B, are not shown to avoid overloading a figure that is intended to more specifically represent the sealing structure. In the discussion of the elements of the sealing structure 200, when two of the elements face each other and include surfaces oriented perpendicular to the stacking axis A50, the surfaces (and by extension the elements) are said to be "adjacent" to each other, while when two surfaces are parallel to the stacking axis A50, the surfaces are said to be "opposing" each other.

[0065] In the illustrated example, the frame 210 of the sealing structure 200 includes wall frames 220, each of which is flush with and surrounds a respective wall 102. In FIG. 5a), the wall frames 220 and the associated walls are shown offset to facilitate distinction between the components, whereas in FIG. 5b), the wall frames 220 are shown flush with the respective walls 102, as in reality. This ensures that each wall frame 220 and the corresponding wall 102 face each other. Preferentially, each wall frame 220 has a thickness substantially equal to the thickness of the corresponding wall 102, for example, ±10%, the thickness being measured parallel to the stacking axis A50.

[0066] The frame 210 of the containment structure 200 also includes compartment frames 230. Each compartment frame 230 is disposed around a corresponding compartment V100, here the second reaction compartment V134. Only one compartment frame 230 is shown in Figure 5. In this embodiment of the containment structure 200, each compartment frame 230 is formed from a single piece.

[0067] Each frame 210 of the sealing structure 200 has a general ring shape, in this example a rectangular ring shape, and is provided, for example by cutting, in a plate of sealing material. The wall frames 220 are made of an electrically insulating material, preferably a polymer material, for example polyethylene terephthalate, also known as PET.

[0068] Each frame 210 comprises two faces 213 facing each other and extending parallel to the mid-plane P50, an inner edge 214 connecting the two faces 213 to each other and oriented towards the inside of the single cell 100, and an outer edge 215 facing the inner edge 214 and connecting the two faces 213 to each other. For each frame 210, the inner edge 214 defines the inner contour of the frame 210 in projection onto the mid-plane P50, while the outer edge 215 defines the outer contour of the frame 210 in projection onto the mid-plane P50.

[0069] In the case of the wall frame 220, the inner edge 214 extends opposite the corresponding wall 102. In the case of the compartment frame 230, the inner edge 214 is oriented toward the corresponding compartment V100 and defines the compartment V100 radially relative to the stacking axis A50.

[0070] Similarly, each wall 102 comprises two faces 103 facing each other and extending parallel to the mid-plane P50, and an outer edge 105 connecting the two faces 103. For each wall 102, the corresponding outer edge 105 is oriented towards the outside of the cell 100. The outer edge 105 of each wall 102 defines the outer contour of the wall 102 in projection onto the mid-plane P50.

[0071] The inner edge 214 of each wall frame 220 is disposed opposite the outer edge 105 of an associated wall 102, and the inner edge 214 of the wall frame 220 and the outer edge 105 of the opposing wall 102 are separated radially relative to the stacking axis A50 by a peripheral gap I220. Thus, each wall 102 is associated with a peripheral gap I220 that is unique to the wall 102 and the corresponding opposing wall frame 220. Thus, each wall frame 220 is associated with a peripheral gap I220 that is unique to the wall frame 220 and the corresponding opposing wall 102.

[0072] The peripheral gap I220 is as small as possible. The peripheral gap I220 is typically comprised between 0 mm (millimeter) and 0.2 mm. In practice, the peripheral gap I220 is not zero, especially due to manufacturing tolerances and assembly clearances. In the illustrated example, I220 is equal to 0.1 mm.

[0073] The sealing structure 200 further comprises an adhesive layer 240 interposed between each of the frames 210 of the sealing structure so as to sealingly attach the frames to one another. Each adhesive layer 240 is thereby sandwiched between two frames 210 and therefore adjacent to each of the two frames 210. In the example shown in Figure 5, two adhesive layers 240 are depicted, each adhesive layer 240 being interposed between a compartment frame 230 on the one hand and one of the walls 102 and the wall frame 220 associated with that wall 102 on the other hand. In other words, each adhesive layer 240 is interposed between the corresponding compartment frame 230 on the one hand and the wall 102 and wall frame 220 adjacent to the compartment frame 230 on the other hand.

[0074] Each adhesive layer 240 is made of a sealing material, preferably a "contact" type adhesive, also called PSA for "Pressure Sensitive Adhesive." Advantageously, each adhesive layer 240 may be repositionable so that the sealing structure 200 is removable, and by extension, the individual cells 100. Non-limiting examples of adhesives include acrylic glue. Each adhesive layer 240 is made of an electrically insulating material. Thus, the sealing structure 200 formed by the assembly of the frames 210 assembled together by the adhesive layers not only provides a seal between two adjacent compartments V100, but also a seal and electrical insulation of each compartment V100 from the outside of the individual cells.

[0075] Advantageously, each adhesive layer 240 extends continuously over the surface of the frame 210 and / or wall 102 to which it is fixed. For example, in the case of the assembly of two surfaces, the adhesive layer 240 is applied by coating to one of the surfaces to be assembled, and then the second surface is pressed onto the adhesive layer 240. In Figure 5a), the two adhesive layers 240 have the same shape as the shape of the compartment frame 230 interposed between them.

[0076] Preferably, the compartment frame 230 is coated with adhesive on each of its two opposing faces before being cut and assembled to the remainder of the encapsulation structure 240 .

[0077] In the illustrated example, the compartment frame 230 is interposed along the stacking axis A50 between two walls 102 and between two wall frames 220 that are coplanar with the two walls 102. This causes the compartment frame 230 to be adjacent to the two wall frames 220.

[0078] For each wall 102 adjacent to a compartment frame 230, the inner contour of the compartment frame 230 is included in the outer contour of the adjacent wall 102 in projection along the stacking axis A50, such that an annular portion of the wall 102 faces the mating portion of the compartment frame 230 along the stacking axis 102, forming a first overlap S231 of the compartment frame 230 on the wall 102. Schematically, the first overlap S231 is a portion of the face 103 of the wall 102, which corresponds to the projection of the compartment frame 230 onto the adjacent wall 102 parallel to the stacking axis A50.

[0079] For each of the wall frames 220 associated with the wall 102 adjacent to the compartment frame 230, the internal contour of the wall frame 220 is included in the external contour of the compartment frame 230 in projection along the stacking axis A50, so that the annular portion of the wall frame 220 faces the mating portion of the compartment frame 230, forming a second overlap S232 of the compartment frame 230 on the wall frame 220. The second overlap S232 corresponds to the projection, parallel to the stacking axis A50, of the compartment frame 230 on the adjacent wall frame 220. The second overlap 232 thereby corresponds to the face 223 of the wall frame 220 that is oriented towards the compartment frame considered here.

[0080] Preferably, the outer contours of all frames 210 of the sealing structure 200 are overlapped with one another along the stacking axis A50, and the outer edges of all frames of all sealing structures together form the outer surface S100 of the single cells 100. The outer surface S50 of the stack 50 corresponds to the union of the outer contours S100 of the single cells 100 that make up the stack 50. Optionally, during assembly of the stack 50, the outer surface S50 is adjusted after assembly of the single cells 100, so that the outer surface S50 is smooth.

[0081] With respect to the adhesive layer 240 interposed between the compartment frame 230 and the adjacent wall 102, the adhesive layer 240 includes a first portion, referred to as the first portion 241 of the layer, which extends opposite the first overlap S231 between the compartment frame 230 and the adjacent wall 102 so as to sealably attach the compartment frame 230 to the adjacent wall 102.

[0082] Similarly, the adhesive layer 240 includes a second portion, referred to as the second portion 242 of the layer, which extends opposite the second overlap S232 between the compartment frame 230 and the adjacent wall frame 220 so as to sealably attach the compartment frame 230 to the wall frame 220.

[0083] The first portion 241 of the layer and the second portion 242 of the layer are disposed in the same plane transverse to the stacking axis A 50. The first portion 241 of the layer is surrounded in cross section by the second portion 242 of the layer.

[0084] Advantageously, the adhesive layer 240 includes a third portion, referred to as the layer third portion 243, which is radially interposed between the layer first portion 241 and the layer second portion 242 in the same plane transverse to the lamination axis A50, and thus bonds the layer first portion 241 and the layer second portion 242 to one another. The layer third portion 243 of the adhesive layer is located opposite the peripheral gap 1220 along the lamination axis A50. The layer third portion 243 of the adhesive layer 240 continuously connects the first layer 242 to the layer second portion 242. In other words, the adhesive layer first portion 241 and the adhesive layer second portion 242 are part of the same continuous layer, here extending across one face of the compartment frame 230, so as to cover the peripheral gap 1220 facing the compartment frame 230.

[0085] The first overlap S231 has a leakage length L231 equal to the smallest distance measured parallel to the mid-plane P50 between any two points belonging to the inner edge 214 of the corresponding compartment frame 230 and the outer edge 105 of the adjacent corresponding wall 102. In the example shown in Figure 5, the leakage length L231 is the length of the shortest path between the compartment V100 and the peripheral gap I220 that passes between the considered compartment frame 230 and the adjacent wall 102.

[0086] Similarly, the second overlap S232 has a leakage length L232 equal to the smallest distance, measured parallel to the mid-plane P50, between any two points belonging to the outer edge 215 of the corresponding compartment frame 230 and the inner edge 214 of the adjacent corresponding wall frame 220. In the example shown in Figure 5, the leakage length L232 of the second overlap S232 is the length of the shortest path between the peripheral gap I220 and the outside of the single cell 100, passing between the considered compartment frame 230 and the adjacent wall frame 220.

[0087] Each leakage length L231 or L232 is at least 1 mm, preferably at least 2 mm, otherwise preferably at least 3 mm, thereby providing a greater than minimum seal between each compartment V100 and the outside of the cell 100 on the one hand, and between two adjacent compartments V100 on the other hand.

[0088] Preferably, the compartment frame 230 and two associated adhesive layers 240 are manufactured by coating two sides of the compartment frame 230 with an adhesive material, whereby the coated compartment frame 230 is then cut to the desired shape before being assembled to the other elements of the single cell 100.

[0089] The assembly formed by the compartment frame 230 coated with the two associated adhesive layers 240 thereby forms a so-called "double-sided adhesive frame." The compartment frame 230 thereby forms the continuous sealed core of the double-sided adhesive frame. Advantageously, during the production of the single cell 100, a double-sided adhesive plate is provided, which comprises a continuous sealed core, here PET, coated on two sides with an adhesive material. The adhesive material is deposited on the two sides of the core, for example, using a coating method. The double-sided adhesive plate is then cut to the desired geometric shape, forming the compartment frame 230 and the two associated adhesive layers 240 in just one step.

[0090] Such a sealing structure 200 does not include an inlet or outlet passage for a fluid within the associated compartment V100. If such an inlet and / or outlet for a fluid needs to be provided within a compartment, it is necessary to use the sealing structure 200 to provide the inlet / outlet elsewhere, for example in one of the walls 102 that define the compartment.

[0091] A sealing structure 300 according to another embodiment is shown in Figure 6. The sealing structure 300 differs from the previously described sealing structure 200 in that it comprises a compartment frame manufactured in the form of a transfer frame 330 provided with two passages 332 for the fluid so as to circulate the corresponding working fluid therethrough towards the compartment V100. Only one passage 332 for the fluid is shown in Figure 6. The transfer frame 330 is therefore part of the frame 210. In this embodiment of the sealing structure 300, each compartment frame 330 comprises only a transfer frame.

[0092] One of the two fluid passages 332 is an inlet for the working fluid, and the other passage 332 is an outlet for the working fluid, the concepts of "inlet" and "outlet" depending on the circulation direction of the working fluid. Thus, the passage 332 for the fluid connects the compartment V100 with the outside of the cell 100.

[0093] Preferably, a passage 332 for the fluid is provided during cutting of the transfer frame 330, which is sandwiched between two adhesive layers 240 to seal and secure the transfer frame 330 to the adjacent wall frame 220 and associated wall 102 to the outside.

[0094] In an alternative form not shown, the passage for the fluid is formed by a partial recess in the transfer frame along the direction of the stacking axis A50, such recess having a depth along the stacking direction less than the thickness of the transfer frame and having a circumferential extent.

[0095] Each passageway 332 opens into the associated compartment V100 through an internal port 334 provided in the inner edge 214 of the transfer frame 330. Each passageway 332 opens to the exterior of the compartment V100 through an external port 335.

[0096] Each passage 332 thereby has an internal portion 334B that opens into the corresponding compartment V100 via the internal port 334. The internal portion 334B of each passage 332 is provided within the thickness of the transfer frame 330. Such a configuration thereby economically provides passages 332 in each of the transfer frames 330 to supply the corresponding working fluid to each compartment V100.

[0097] In the example shown, the external port 335 of each passage 332 of the transfer frame 330 is advantageously provided at the outer edge 215 of the transfer frame 335 so as to be in fluid communication with one of the circulation conduits 38A, 38B or 38C, so that one of the passages 332 of the transfer frame 330 communicates with one of the circulation conduits 38A, 38B or 38C, while the other passage 332 of the same transfer frame 330 communicates with the other of the circulation conduits 38A, 38B or 38C belonging to the same pair of conduits.

[0098] In other words, for each of two passages 332 of the same transfer frame 330, the associated external port 335 of the passage 332 opens onto the outer edge 215 of the transfer frame 330 into a separate conduit within the associated pair of circulation conduits.

[0099] In a variant not shown, the external ports 335 are arranged differently, for example axially oriented and located on one of the faces 213 of the transfer frame 330, which are then preferably aligned along the stacking axis A50 to form a chimney extending through the frame 210, which chimney is intended for the circulation of the working fluid, repeating the arrangement known in the field of so-called "internal manifold" plates.

[0100] Advantageously, each passage 332 contains a fin 336 for guiding the associated working fluid. Alternatively, only one of the two passages 332 is provided with a fin 336. Within each fluid passage 332, the fin 336 forms a pillar that maintains the two associated adhesive layers 240 at a distance from the transfer frame 330 under consideration. Two adjacent fins 336 define a channel between them. Each fluid passage 332 is thus formed by the union of the channels defined between the fins 336. The shape of each fin 336 is selected to impede as little as possible the flow of working fluid through the passage 332 while allowing the transmission of a mechanical clamping force of the stack 50, the clamping force being parallel to the stack axis A50.

[0101] The fins 336 are preferably formed by cutting the transfer frame 330 during its manufacture. The fins 336 therefore have the same thickness as the rest of the transfer frame 330. When the cell 100 is assembled, the fins 336 are held in place by adhesive layers disposed on both sides of the transfer frame 330 under consideration, here adhesive layers 240 between which the transfer frame 330 is interposed. The fins 336 are advantageously spaced apart within the corresponding passages 332 to guide the flow of the associated working fluid. Preferably, the fins 336 are regularly distributed within the corresponding passages 332.

[0102] Another embodiment of a sealing structure 400 is shown in FIG. 7. The sealing structure 400 differs from the previously described sealing structure 300 in that, in addition to the transfer frame 330 interposed between the two corresponding adhesive layers 240, the sealing structure 400 includes a compartment frame 430 that includes an additional frame, referred to as a first sealing frame 432, interposed between the transfer frame 330 and one of the adhesive layers 240 associated with the transfer frame 330. Thus, the first sealing frame 432 is adjacent to a wall 102, and is attached to that wall by one of the adhesive layers 240. In other words, the first sealing frame 432 is interposed between the transfer frame 330, on the one hand, and one of the two walls 102 adjacent to the transfer frame 330, on the other hand. In the example shown in FIG. 7, the first sealing frame 432 is associated with the wall 102 and the wall frame 220 located at the bottom of the figure.

[0103] The compartment frame 430 further includes an adhesive film 440 interposed between the first seal frame 432 and the transfer frame 330 to attach the transfer frame 330 to the adjacent first seal frame 432 .

[0104] Preferably, the adhesive film 440 is made of a sufficiently hard material selected herein to avoid creeping of the adhesive under the influence of pressure, in particular between the fins 336, and thereby to avoid blocking of the passages 332 for the fluid. The adhesive film 440 is provided herein with i tabs 441 that correspond to the fins 336 of the transfer frame 330. The tabs 441 form discontinuous portions of the adhesive film 440 here. In a variant (not shown), the adhesive film 440 does not have tabs and is continuous along the circumferential direction around the lamination axis A50, similar to the adhesive layer 240.

[0105] As a result, the transfer frame 330, and more specifically the fins 336, are attached to the first sealing frame 432 by the first adhesive film 440, while the first sealing frame 432 is sealed to the adjacent wall 102 and to the wall frame 220 on the opposite side of the wall 102 by the corresponding adhesive layer 240.

[0106] The sealing frame 432, which extends continuously along the radial direction and along the circumferential direction around the stacking axis A50, faces the peripheral gap I220 provided between the wall 102 and the opposing wall frame 210, thereby providing a continuous support for the adhesive layer 240a, which improves the sealing of the corresponding compartment V100 compared to the situation without the sealing frame 432. The presence of the sealing frame 432 is particularly advantageous when the working fluid circulating in the compartment V100 is gaseous, in other words when the transfer frame 330 is provided around the first reaction compartment V132 or around the second reaction compartment V134, in which hydrogen and air circulate, respectively.

[0107] Preferably, the sealing frame 432 has the same shape as the transfer frame to which it belongs, in the sense of the same internal and external contours. Likewise, preferably, the adhesive film 440 has the same shape as the first sealing frame 432 and the corresponding transfer frame, in the sense of the same internal and external contours.

[0108] Thereby, the sealing frame 432 is preferably adjacent to the membrane 130 on the side where the working fluid is hydrogen, and to the wall frame opposite the membrane 130, in order to prevent the risk of hydrogen contamination on the other side of the membrane 130. Otherwise, preferably, the sealing frame 432 is arranged in each of the reaction compartments V132 and V134, on both sides of the membrane 130, in order to prevent gas transfer between the two reaction compartments V132 and V134.

[0109] Preferably, the sealing frame 432 and associated adhesive layer 240 are manufactured by coating one of the two sides of the sealing frame 432 with an adhesive material, whereby the coated sealing frame 432 is then cut to the desired shape before being assembled with the other elements of the single cell 100.

[0110] The assembly formed by the sealing frame 432 coated with the associated adhesive layer 240 thereby forms a so-called "single-sided adhesive frame." The sealing frame 432 thereby forms a continuous sealing core of the single-sided adhesive frame, and this continuity is radial and circumferential. Advantageously, during the manufacture of the individual cells 100, a single-sided adhesive plate is provided, which comprises a continuous sealing core, here PET, coated on one of its two sides with an adhesive material. The adhesive material is deposited, for example, by coating on one of the faces of the core. The single-sided adhesive plate is then cut to the desired geometric shape, forming in one step the sealing frame 432 and the associated adhesive layer 240, both of which are continuous radially and circumferentially over the entire extent of the sealing frame 432.

[0111] A sealing structure 500 according to another embodiment is shown in Figure 8. The sealing structure 500 differs from the sealing structure 400 described above in that, for each transfer frame 330, the sealing structure 500 comprises two sealing frames 432 arranged on either side of the transfer frame 330. The sealing structure 500 further comprises a second adhesive film 440 interposed between the second sealing frame 432 and the compartment frame 330.

[0112] 6 and 7, in the case of the sealing structure 500 shown in Fig. 8, the surface of the adhesive film 440 oriented towards the fluid passage 332 is further reduced, which reduces the risk of contamination of the compartment V100 and the working fluid circulating in this compartment V100. Also, the risk of blockage of the fluid passage 332 due to creep of the adhesive film 442 is reduced.

[0113] The first and second sealing frames 432 are each interposed between the transfer frame 330, on the one hand, and one of the two respective adhesive layers 240, on the other hand. The second sealing frame 432 is attached to the wall 102 and the corresponding wall frame 210 by the corresponding adhesive layer 240, on the one hand, and to the transfer frame 330 by the second adhesive film 440, on the other hand. In other words, in this embodiment of the closure structure 500, the transfer frame 330, the two sealing frames 432, and the two adhesive films 440 together form the compartment frame 530 of the closure structure.

[0114] Advantageously, for each of the two sealing frames 432, an associated adhesive layer 240 is coated onto the sealing frame 432 to form a single-sided adhesive frame. During manufacture, each frame 432 and associated adhesive layer 240 are formed during the same process by cutting a single-sided adhesive plate.

[0115] For each wall 102 of a single cell 100, when the compartments located on each side of the wall 102 comprise a transfer frame 330 sandwiched between two adhesive films 440, it is understood to be particularly advantageous to seal the gap 1220 on at least one of the faces 103 of the wall 102 using a sealing frame 432 and an associated adhesive layer 240, since the adhesive films 440 may not be sufficient to ensure a sufficient seal. When the wall 102 is a membrane 130, the membrane 130 is preferably sealed on each of its two faces by a sealing frame 432 with an associated adhesive layer 240, so as to keep the membrane 130, which is preferably made here of a fluorinated polymer and which is more fragile and difficult to bond than the separators 110 and 120, which are made here of stainless steel.

[0116] 8, the compartment V100 under consideration is defined by two sealing frames 432 and by associated adhesive layers 240, further improving the sealing of the frame V100. More specifically, the compartment V100, in which the working fluid is hydrogen, is preferably defined by such a sealing structure comprising two sealing frames 432 on either side of the compartment frame 330.

[0117] Otherwise, preferably, all compartments V100 through which gas circulates, in this case the first reaction compartment V132 and the second reaction compartment V134, are each defined by two sealing frames 432 on either side of the compartment frame 330 associated with this reaction compartment.

[0118] FIG. 9 shows, for the considered compartment V100, in insets a) and b), respectively, two alternative sealing structures 500' and 500'' to the sealing structure 500 represented in FIG.

[0119] In comparison with the sealing structure 500 shown in FIG. 8 , in the case of the sealing structure 500′ shown in FIG. 9 a), one of the sealing frames 432 and the associated adhesive layer 240 of the sealing frame 432 are arranged on the other side of one of the walls 102 defining the compartment V100, in this case, on the other side of the wall 102 located at the bottom of FIG. 9 a). Thus, the sealing frame 432 belongs to the compartment frame of the adjacent compartment of the considered compartment V100, located on the other side of the wall 102 located at the bottom of FIG. 9 a. Therefore, the associated adhesive layer 240 of the wall 102 is interposed between the sealing frame 432 and the wall 102 to seal the gap 1220 on the other side of the wall 102 relative to the considered compartment V100. The gap 1220 is not shown in FIG. 9 .

[0120] In comparison with the sealing structure 500 shown in FIG. 8, in the case of the sealing structure 500″ shown in FIG. 9b), the two sealing frames 432 and the associated adhesive layers 240 of each of those sealing frames 432 are disposed on the other side of the two walls 102 that define the compartment V100. In other words, the transfer frame 330 associated with the compartment V100 in FIG. 9b) is interposed between the two wall frames 220 that directly frame it in the stacking direction A50, without any sealing frame interposed between the transfer frame 330 and the two wall frames 220. However, such a sealing frame 432 is provided in direct contact with each of the two wall frames 220, with only an adhesive layer 240 interposed between the sealing frame 432 and the wall frame for each wall frame. Thus, in the stack, the two sealing frames 432 each belong to one of the two compartment frames of two adjacent compartments of the compartment V100 under consideration, located respectively on the other side of the wall 102 located at the bottom in FIG. 9b) and on the other side of the wall 102 located towards the top in FIG. 9b).

[0121] In all cases where the compartment frame is provided with a sealing frame 432, and in particular in all cases where the sealing frame 432 is interposed between the transfer frame 330 and the wall frame 220 belonging to the same compartment frame, the adhesive layer 240 thus interposed between the sealing frame on the one hand and the wall 102 and its associated wall frame 220 on the other hand necessarily includes a first portion of the layer extending opposite the first overlap between the compartment frame (herein the sealing frame is part of the compartment frame) and the wall so as to sealingly attach the compartment frame to the wall. Thus, the first portion of the layer 241 faces and contacts the sealing frame 432 and the wall in such cases. The same adhesive layer 240 includes a second portion of the layer 242, which extends opposite the second overlap between the compartment frame (herein the sealing frame is also part of the compartment frame) and the wall frame so as to sealingly attach the compartment frame to the wall frame. Thus, the second portion of the layer 242 faces and contacts the sealing frame 432 and the wall frame 220 in such cases. It will be appreciated that the first portion 241 of the adhesive layer and the second portion 242 of the adhesive layer are preferably part of the same adhesive layer 240 that extends continuously across one surface of the compartment frame, in this case the surface of the sealing frame 432, as shown, and thus the two portions, the first portion 241 and the second portion 242 of the adhesive layer, are continuous both radially and circumferentially across the entire extent of the sealing frame 432 so as to close the peripheral gap I220 opposite the compartment frame 220.

[0122] Thus, the sealing structures 500, 500' and 500'' depicted in Figures 8 and 9 can be selected for each of the compartments V100 of the single cell 100, and by extension for the stack 50, as required.

[0123] Generally, the thickness of each element of the sealing structure 200, 300, 400 or 500, i.e., the thickness of the wall frame 220, the partition frame 220, the transfer frame 330, the sealing frame 432, as well as the thickness of the adhesive layer 240 or the adhesive film 440, is adjusted according to the structure of each single cell 100, more particularly according to the properties of each wall 102 and according to the various factors received in each of the compartments V100 of the single cell 100.

[0124] Each sealing frame 432 is therefore made of a polymer material, for example PET, and has a thickness, measured parallel to the stacking axis A50, comprised between 10 μm and 20 μm, preferably equal to 12 μm.

[0125] The adhesive film 440 interposed between each sealing frame 432 and the corresponding transfer frame 330 has a thickness, measured parallel to the lamination axis A50, comprised between 6 μm and 30 μm, preferably comprised between 8 μm and 20 μm, preferably comprised between 10 μm and 15 μm.

[0126] Each transfer frame 330 is made of a polymer material, for example PET, and has a thickness, measured parallel to the stacking axis A50, comprised between 50 μm and 600 μm, preferably comprised between 80 μm and 150 μm, and preferably equal to 100 μm.

[0127] For each adhesive layer 240, the first part of the layer and the second part of the layer each have a thickness, measured parallel to the lamination axis, comprised between 15 μm and 30 μm, preferably comprised between 18 μm and 25 μm, preferably equal to 20 μm. Preferably, the thickness is the same for the first part of the layer and the second part of the layer.

[0128] A single cell 100 is represented schematically in cross section in Figure 10. As indicated by the dotted lines, the single cell is repeated in the stack.

[0129] The first reaction compartment V132 herein contains an example of a second type of spacer 700. Around the first reaction compartment V132, the frame 210 forming the compartment frame corresponding to that compartment comprises a transfer frame 330 providing two passages 332 associated with the first reaction compartment V132, and two sealing frames 432, one on each side of the transfer frame 330, each attached to the transfer frame 330 by a respective adhesive film 440.

[0130] The second reaction compartment V134 herein contains an example of a first type of spacer 600. Around the second reaction compartment V134, the frame 210 forming the compartment frame corresponding to the reaction compartment V134 comprises a transfer frame 330 providing two passages 332 associated with the second reaction compartment V132, and two sealing frames 432, one on each side of the transfer frame 330, each attached to the transfer frame 330 by a respective adhesive film 440.

[0131] The cooling compartment V136 herein contains a second example of a second type of spacer 700. Around the periphery of the cooling compartment V136, the frame 210 forming the compartment frame corresponding to that compartment comprises only a transfer frame 330 providing two passages 332 associated with the cooling reaction compartment V132.

[0132] However, it should be noted that a given sealing structure can be used regardless of the type of spacer included in a given compartment.

[0133] In FIG. 10 , the passages 332 are represented schematically by dashed arrows. More specifically, the passages 332 of each of the compartments V132, V134, and V136 are represented as if they were aligned along the stacking axis A50, and the illustration is schematic. As can be seen in FIG. 4 , the circumferential position and extent of the passages 332 are adjusted depending on the type and orientation of the washing spacer 600 or 700. Preferably, as shown in FIG. 4 , the passages 332 of each of the compartments V132, V134, and V136 of the same single cell 100 are offset from each other around the cell periphery, preferably substantially opposite each other. Meanwhile, the passages 332 of each of the first reaction compartments V132 of all single cells 100 of the stack are preferably aligned along the stacking axis A50. Similarly, the passages 332 of each of the second reaction compartments V134 of all single cells 100 in the stack are preferably aligned along the stack axis A50, and the passages 332 of each of the cooling compartments V136 of all single cells 100 in the stack are preferably aligned along the stack axis A50.

[0134] 10 , the first reaction compartment V132 and the second reaction compartment V134 are each defined by a compartment frame comprising two respective sealing frames 432 arranged on either side of the transfer frame 300, each sealing frame 432 being adjacent to a respective wall 102. Thus, the peripheral gap 1220 associated with the wall 102 separating the two reaction compartments V132 and V134, i.e., the gap 1220 associated with the membrane 130, is sealed on both sides of the membrane 130 by the respective sealing frames 432. For each compartment frame of the first reaction compartment V132 and the second reaction compartment V134, each sealing frame 432 is attached to the transfer frame by an adhesive film 440. The compartment frame thus formed is associated with two adhesive layers 240 arranged on either side of the compartment frame along the stacking axis A50. Thus, each of the two adhesive layers 240 is interposed between the sealing frame 432, on the one hand, and the wall 102 and the wall frame 220 associated with that wall, on the other hand.

[0135] 10, the cooling compartment V136 is defined by a compartment frame that includes only the transfer frame 330, without a sealing frame 432. Thus, the peripheral gap I220 associated with the first separator 110 is sealed by the sealing frame 432 on only one side of the first separator 110, which sealing frame 432 belongs to the compartment frame of the adjacent compartment, here the first reaction compartment V132. Similarly, due to the pattern effect resulting from the stacking of identical cells, the peripheral gap I220 associated with the second separator 120 is sealed by the sealing frame 432 on only one side of the first separator 110, which sealing frame 432 belongs to the compartment frame of the first reaction compartment V132. Of course, to ensure sealing, the cooling compartment V136 could also have been provided with a compartment frame that includes a sealing frame on one side of the transfer frame 330 or two sealing frames on each side of the transfer frame 330.

[0136] An alternative embodiment of a single cell 200 is shown in Figure 11. The single cell 200 comprises a first reaction compartment V132 and a second reaction compartment V134, but does not comprise a cooling compartment. Cooling of the single cell 200 is provided herein by the passage of circulating air through the second reaction compartment V134.

[0137] Unlike the single cell 100 of the previous embodiment, the second reaction compartment V134 is defined here by a compartment frame comprising only one sealing frame 432. In the example shown in Figure 11, the peripheral gap I220 associated with the membrane 130 is sealed on one side by the sealing frame 432. To compensate for the lack of a sealing frame without reducing the height of the compartment, the transfer frame 330 received in the second reaction compartment here has a greater thickness than the transfer frame 330 of the previous embodiment, whereby the passages 332 for fluids allow a higher flow rate of the associated working fluid, here air, which serves both the electrochemical reaction of the fuel cell and the cooling of the cell.

[0138] Regardless of the number of compartments V100 of a single cell 100, whether or not there is a cooling compartment V136, for each compartment V100 and for each of the walls 102 defining the compartment V100, the peripheral gap I220 associated with the wall 102 is sealed on at least one of the faces of the wall 102 by a sealing frame 432 attached to this wall by an associated adhesive layer 240. In other words, the peripheral gap I220 associated with a wall 102 is sealed on at least one of the faces of this wall by a continuous frame around the entire perimeter of the gap I220.

[0139] Preferably, the reaction compartment in which hydrogen circulates, here the first compartment V132, is defined by a compartment frame comprising two sealing frames 432 arranged on either side of the transfer frame 330 along the stacking axis A50, each sealing frame 432 sealing a peripheral gap I220 associated with two walls 201 defining this reaction compartment. Each sealing frame is attached to the transfer frame by an adhesive film 440. The compartment frame thus formed is associated with two adhesive layers 240 arranged on either side of the compartment frame along the stacking axis A50. Each of the two adhesive layers 240 is thus interposed between the sealing frame 432, on the one hand, and the wall 102 and the wall frame 220 associated with that wall, on the other hand.

[0140] Preferably, each seal frame 432 and associated adhesive layer 240 is made by cutting from a single-sided adhesive sheet.

[0141] Preferably, each transfer frame 330 and two associated adhesive films 440 are made by cutting from a double-sided adhesive sheet.

[0142] Here, a first type of cleaning spacer 600 will be described with reference to FIGS.

[0143] The cleaning spacer 600, also referred to simply as "spacer 600," has a flat, generally rectangular shape with two large, opposing sides and two small, opposing sides extending perpendicular to a height axis A600. When the spacer 600 is received in a corresponding compartment V100, the height axis A600 is parallel to the stacking axis A50. The large sides extend parallel to the longitudinal axis X600 of the spacer 600, while the small sides extend parallel to the transverse axis Y600 of the spacer 600. The longitudinal axis X600, transverse axis Y600, and height axis A600 together form an orthogonal frame of reference.

[0144] The spacer 600 includes two distribution plates 602, including a first plate 602A and a second plate 602B. The distribution plates 602 each include two opposing faces, including a first face 604 and a second face 605.

[0145] The two plates 602 are stacked flat against each other along a height axis A600 that is perpendicular to the mid-plane P600 of the cleaning spacer 600. Thus, when the spacer 600 is received in the compartment V100, the mid-plane P600 of the cleaning spacer 600 is perpendicular to the stacking axis A50 or parallel to the mid-plane P50 of the corresponding single cell 100.

[0146] Each distribution plate 602 is manufactured by cutting from a metal sheet and has a thickness comprised between 30 μm and 300 μm, preferably comprised between 50 μm and 100 μm, otherwise preferably equal to 75 μm within ±5%. Preferably, the distribution plates 602 have the same thickness.

[0147] Each distribution plate 602 includes perforations 610 formed by cutting the distribution plate 602. The perforations 610 are through, meaning that the perforations 610 are open on both opposing faces 604 and 605 of the distribution plate 602.

[0148] The perforations 602 are arranged to form a network of channels 612 when the two plates 602 are stacked, and the network of channels 612 is configured to form a flow field for the working fluid circulating within the compartment V100 in which the cleaning spacer 600 is housed.

[0149] The washing spacer 600 comprises an inlet 613A for a fluid and an outlet 613B for a fluid, the inlet 613A and the outlet 613B being fluidly connected to each other by a network of channels 612. The concepts of "inlet" and "outlet" are relative and depend on the direction of flow of the flowing fluid. In the example shown, the inlet 613A and the outlet 613B are correspondingly arranged on the small side of the spacer 600.

[0150] The perforations 610 of each distribution plate 602 have an elongated shape, with two adjacent perforations 610 extending along each other and separated from each other by a strip of material 614. Each perforation 610 is defined by two opposing longitudinal edges 616, each of which corresponds to an edge of one of the two strips of material 614 that define each perforation 610.

[0151] Each distribution plate 602 further comprises a cross-member 618 that extends across the perforations 610 in the thickness of the distribution plate 602 and maintains the strips 614 at a distance from each other, such that each cross-member 618 connects two longitudinal edges 616 of the perforations 610 through which the cross-member 618 extends.

[0152] Each strip 614 of the first plate 602A is overlapped with a respective strip 614 of the second plate 602B along the height axis A 600 to define a first portion 620 of the network of channels 612. In other words, in the first portion 620 of the network of channels 612, each perforation 610 of the first plate 602A is aligned with each perforation 610 of the second plate 602B along the height axis A 600 to form each channel of the network 612. The cleaning spacer 600 herein includes only one portion 620; in other words, the first portion 620 represents the entire network of channels 612. The first portion 620 of the network 612 is represented by a dotted frame.

[0153] The first portion 620 of the network of channels 612 corresponds in each of the distribution plates 602 to a first portion 621 of the distribution plate 602. Thus, for each distribution plate 602 of the first type of washing spacer 600, the first portion 621 of the plate 602 represents the entire plate.

[0154] The cross members 618 of the first plate 602A are offset in the midplane P600 of the spacer 600 relative to the cross members 618 of the second plate 602B so as not to interfere with the circulation of working fluid within the channels of the first portion 620 of the network of channels 612 of the cleaning spacer 600.

[0155] 13, inset c), a detail of the spacer 600 is shown sandwiched between two elements of the cell 100, namely the membrane 130 and the second separator 120. The circulation of the working fluid is represented by arrows F612. The fluid circulating in each channel of the network 612 flows along each channel, bypassing the cross members 618 that are offset from one another along the direction of the channel, and it can be seen that the two cross members 618 of the spacer 600 that do not belong to the same distribution plate 602 are thus offset from one another along the direction of the channel.

[0156] In the first portion 620 of the network of channels, the strips 614 of each distribution plate 602 are preferably parallel to one another. As a result, the perforations 610, and therefore the channels of the network 612, are also parallel to one another to reduce the pressure drop of the working fluid circulating within the spacer 600.

[0157] Advantageously, for each distribution plate 602 for a given compartment's cleaning spacer 600, each strip 614 of material extends continuously from a fluid inlet 613A to a fluid outlet 613B of the spacer 600, such that each channel of the network 612 extends continuously from the inlet 613A to the outlet 613B. In other words, there is no branching or connection of the perforations 610 to reduce the pressure drop of the working fluid circulating within the spacer 600.

[0158] Preferably, in the first portion 620 of the network of channels 612, the strips 614 of the cleaning spacer 600 are straight in an orthogonal projection onto the midplane P600 of the spacer 600. Thereby, the channels of the first portion of the network of channels are straight.

[0159] Preferably, in the first portion 620 of the network of channels 612, the perforations 610 each have the same width l 610 comprised between 0.2 mm and 1.1 mm, while the strips 614 of material separating two adjacent perforations 610 each have a width l 614 comprised between 0.2 mm and 0.7 mm, thereby achieving both a good flow of the working fluid and a good transmission of the compressive forces parallel to the height axis A 600, which are exerted on the spacer 600 when it is received in the fuel cell 20.

[0160] Preferably, in the first portion 620 of the network of channels 612, each cross member 618 has a height equal to the height of the strip of material 614 adjacent the perforation 610 in which the cross member 618 is located, the height of the cross member and the height of the strip being measured parallel to the height axis. Thus, the manufacturing process is simplified and each distribution plate 602 is manufactured by simple cutting.

[0161] 14 and 15, a second type of cleaning spacer 700 will now be described. Elements identical to those of the first type of cleaning spacer 600 have the same reference numerals.

[0162] In the first type of spacer 600, each channel of the network of channels 612 is linear from end to end, i.e., from the inlet 613A to the outlet 613B, whereas the second type of spacer 700 includes a network of channels 712 in which each channel is formed from multiple linear portions, and two consecutive portions are not aligned with each other.

[0163] The spacer 700 comprises an inlet 713A and an outlet 713B, each provided on one of the large sides of the rectangle. Advantageously, each channel of the network 712 extends continuously from the inlet 713A to the outlet 713B.

[0164] The network of channels 712 includes a plurality of distinct portions, within each portion the perforations 610 are parallel to one another, with two adjacent perforations 610 separated from one another by a respective strip 614 of material.

[0165] In the illustrated example, the network of channels 712 includes three consecutive portions, including a first portion 714A, a second portion 714B, and a third portion 714C, the outlines of which are shown by dotted lines in Figures 14 and 15. More generally, the number of portions is selected according to the geometry of the spacers, the layout of the inlets and outlets for the fluids, etc. What is valid for the first portion 714A and the second portion 714B of the network of channels 712 can be transposed to any two consecutive portions of the network of channels 712.

[0166] The spacer 700 comprises two distribution plates 702, including a first plate 702A and a second plate 702B. Portions 714A, 714B, and 714C of the network of channels 712 are visible on each of the plates 702, with reference numerals 724A, 724B, and 724C. In FIG. 14, only the first portion 724A and the second portion 724B of each of the first distribution plate 702A and the second distribution plate 702B are visible. The operating principle of the spacer 700 will be explained with reference to the first portion 714A and the second portion 714B of the network of channels 712.

[0167] For each of the first distribution plate 702A and the second distribution plate 702B, in each of the first portion 724A and the second portion 724B, the perforations 610 are parallel to each other, and two adjacent perforations 610 are separated from each other by respective strips 614 of material.

[0168] Each strip 614 of the second portion 724B of the first plate 702A is superimposed with a respective strip 614 of the second portion 724B of the second plate 702B along the height axis A600 to form a channel of the second portion 714B of the network of channels 712 of the cleaning spacer 700, and the channels of the second portion 714B of the network of channels 712 are parallel to each other.

[0169] For each distribution plate 702A or 702B, each strip 614 of the first portion 724A of this distribution plate extends contiguously with the strip 614 of the second portion 724B of the same distribution plate.

[0170] For each distribution plate 702A or 702B, the strips 614 of the first portion 724A are straight and parallel to one another, and the channels of the first portion 714A of the network 712 extend along a first flow axis 716A, while the strips 614 of the second portion 724B are straight and parallel to one another, and the channels of the second portion 714B of the network 712 extend along a second flow axis 716B. The first flow axis 716A and the second flow axis 716B are each represented by respective arrows in Figures 14 and 15. The first flow axis 716A is parallel to the transverse axis Y600 herein, while the second flow axis 716B is parallel to the longitudinal axis X100 herein.

[0171] The first flow axis 716A and the second flow axis 716B are separate, meaning that the working fluid circulating within each channel of the network 712 changes direction as it passes from the first portion 714A to the second portion 714B.

[0172] The first flow axis 716A and the second flow axis 716B form an angle between 1° and 179°, preferably between 30° and 150°, otherwise preferably between 60° and 120°. In the example shown, the first flow axis 716A and the second flow axis 716B form an angle between them equal to 90°.

[0173] In the example shown, each of the first reaction compartment V132, the second reaction compartment V134 and the first cooling compartment V126 contains a cleaning spacer 600 or 700 according to the invention.

[0174] In a variant not shown, only one of the housings V100 of the single cell 100 receives a cleaning spacer of another type, while the other two housings V100 each receive a cleaning spacer according to the invention. According to another variant not shown, only one of the housings V100 of the single cell 100 receives a cleaning spacer according to the invention, while the other two housings V100 each receive a cleaning spacer of another type.

[0175] The above embodiments and variations can be combined with each other to create new embodiments of the present invention.

Claims

1. A single cell (100) of a stack (50) of a fuel cell (20), comprising: The single cell comprises a plurality of walls (102), each of which is continuous and sealed and stacked on top of one another along a stacking axis (A50), the walls (102) defining compartments (V100) of the single cell; a first separator (110); a second separator (120); a proton exchange membrane (130) interposed between the first separator and the second separator; Including, the first separator defines a first reaction compartment (V132) by the membrane, the first reaction compartment (V132) being configured to receive a first working fluid of the fuel cell; the second separator defines a second reaction compartment (V134) by the membrane (130), the second reaction compartment (V132) being configured to receive a second working fluid of the fuel cell; the compartment (V100) of the single cell comprises the first reaction compartment (V132) and the second reaction compartment (V134), the cell further comprises a sealing structure (200; 300; 400; 500), the sealing structure comprising frames (210) each made of a polymer material and stacked along the stacking axis (A50), the frames being arranged around the walls (102) and around the compartments, For at least one of the compartments (V100) of the single cell (100) and for at least one of the two walls (102) defining said at least one compartment, The frame (210) of the sealing structure wall frames (220) coplanar with and surrounding a corresponding wall, the inner edge (214) of each wall frame (220) being positioned opposite the outer edge (105) of the wall (102), the inner edge of the wall frame (220) and the outer edge of the wall being opposite each other and separated by a peripheral gap (1220), each wall frame (220) having a thickness substantially equal to the thickness of the corresponding wall (102); a compartment frame (230; 330; 430; 530) arranged around the corresponding compartment (V100), the compartment frame (230; 330; 430; 530) having an inner edge (214) oriented towards the corresponding compartment (V100) and defining the compartment in a radial direction relative to the stacking axis (A50), and an outer edge (215) opposite the inner edge, the inner edge having an internal contour, while the outer edge has an external contour; an adhesive layer (240) interposed between the compartment frame on the one hand and the wall and wall frame adjacent to the compartment frame on the other hand, respectively, so as to attach the frames together in a sealed manner; Including, the inner contour of the compartment frame (230; 330; 430; 530) is included in the outer contour of the wall in projection along the stacking axis (A50), so that an annular portion of the wall faces the mating portion of the compartment frame along the stacking axis, forming a first overlap (S231) of the compartment frame on the wall; the inner contour of the wall frame (220) is included in the outer contour of the compartment frame in projection along the stacking axis, so that an annular portion of the wall frame faces a mating portion of the compartment frame, forming a second overlap (S232) of the compartment frame on the wall frame; the adhesive layer includes a first portion (241) of the layer extending opposite the first overlap (S231) between the compartment frame and the adjacent wall so as to sealingly attach the compartment frame to the wall; the adhesive layer includes a second portion (242) of the layer extending opposite the second overlap between the compartment frame and the adjacent wall frame to sealingly attach the compartment frame to the wall frame; A single cell (100).

2. the first separator (110) is configured to sealingly separate the first reaction compartment (V132) from a first cooling compartment (V136) configured to receive a third working fluid of the fuel cell (20); 2. The single cell (100) of claim 1, wherein the compartment (V100) of the single cell includes the first cooling compartment (V136) in addition to the first reaction compartment (V132) and the second reaction compartment (V134).

3. 3. A single cell (100) according to claim 1 or claim 2, wherein the first portion (241) of the adhesive layer and the second portion (242) of the adhesive layer are part of the same adhesive layer (240) extending continuously on one face of the compartment frame (230; 330; 430; 530) so as to close the peripheral gap (I220) adjacent to the compartment frame.

4. the first overlap (S231) has a leakage length (L231) equal to the smallest distance measured parallel to the mid-plane (P50) between any two points belonging to the inner edge (214) of the corresponding compartment frame and the outer edge (105) of the corresponding adjacent wall, - said second overlap (S232) has a leakage length (L232) equal to the smallest distance measured parallel to said mid-plane (P50) between any two points belonging to the outer edge (215) of said corresponding compartment frame and the inner edge (214) of said corresponding adjacent wall frame, A single cell (100) according to any one of claims 1 to 3, wherein each leakage length is 1 mm or more, preferably 2 mm or more, otherwise preferably 3 mm or more.

5. For at least one of the compartment frames: the compartment frame includes a transfer frame (330) providing two passages (332) for a fluid, the two passages being provided for the circulation of the associated working fluid between the corresponding compartment (V100) and the outside of the single cell (100); Each passage (332) opens into the associated compartment (V100) through an internal port (334) provided in the inner edge (214) of the transfer frame; A single cell (100) according to any one of claims 1 to 4, wherein each passage (332) opens to the outside of said compartment (V100) through an external port (335).

6. 6. The single cell (100) of claim 5, wherein each passage (332) includes an internal portion (334B) that opens into the compartment (V100) through the internal port (334), and the internal portion (334B) of the passage is provided within the thickness of the transfer frame (330).

7. 7. The single cell (100) of claim 5 or claim 6, wherein the external port (335) is provided at an outer edge (215) of the transfer frame (330).

8. For at least one transfer frame (330), At least one of the two passages (332) contains fins (336) for guiding the associated working fluid; the fins are formed by cutting the transfer frame (330) and are spaced apart from one another within the corresponding passages to direct the flow of the associated working fluid; The single cell (100) of any one of claims 5 to 7, wherein the fins (336) are maintained by the adhesive layer (240) with the corresponding transfer frame interposed therebetween.

9. For at least one of the first reaction compartment (V132) and the second reaction compartment (V134), the compartment frame (430; 530) comprises: the transfer frame (330); a first sealing frame (432) interposed between the transfer frame on the one hand and a first wall of the two walls (102) adjacent to the compartment frame and the wall frame (220) opposite the first wall on the other hand; a first adhesive film (440) interposed between the first sealing frame (432) and the transfer frame (330); Equipped with 9. A single cell (100) according to any one of claims 5 to 8, wherein the first sealing frame (432) is attached, on the one hand, to the first wall (102) and the opposing wall frame (220) by the associated adhesive layer (240), and, on the other hand, to the transfer frame (330) by the first adhesive film (440).

10. The compartment frame (530) comprises, in addition to the first sealing frame (432), a second sealing frame (432), the first and second sealing frames being arranged on both sides of the transfer frame (330), the second sealing frame being interposed between the transfer frame on the one hand and a second wall of the two walls (102) adjacent to the compartment frame and the wall frame (220) associated with the second wall on the other hand, the second wall being different from the first wall; a second adhesive film (440) interposed between the second sealing frame (432) and the transfer frame (330); Equipped with 10. The single cell (100) of claim 9, wherein the second sealing frame (432) is attached to the second wall (102) and the opposing wall frame (220) on the one hand by the corresponding adhesive layers (240), and to the transfer frame (330) on the other hand by the second adhesive film (440).

11. 11. A single cell (100) according to claim 9 or claim 10, wherein for at least one sealing frame (432), the adhesive film (240) associated with the sealing frame is coated continuously on one side of the sealing frame (432).

12. For at least one sealing frame (432): said sealing frame is made of a polymer material, for example PET, and has a thickness, measured parallel to said lamination axis (A50), comprised between 10 μm and 20 μm, preferably equal to 12 μm, 12. A single cell (100) according to any one of claims 9 to 11, wherein the adhesive film (440) interposed between the sealing frame and the corresponding transfer frame (330) has a thickness, measured parallel to the stacking axis, comprised between 6 μm and 30 μm, preferably comprised between 8 μm and 20 μm, preferably comprised between 10 μm and 15 μm.

13. A single cell (100) according to any one of claims 9 to 12, wherein for each compartment (V100) of the single cell and for each of the walls (110, 120, 130) defining the compartment (V100), the peripheral gap (I200) associated with the wall is sealed on at least one of the faces of the wall by a sealing frame (432).

14. For at least one transfer frame (330), this transfer frame is made of a polymeric material, for example PET, and has a thickness, measured parallel to said stacking axis (A50), comprised between 50 μm and 200 μm, preferably comprised between 80 μm and 150 μm, otherwise preferably equal to 100 μm, 14. A single cell (100) according to any one of claims 5 to 13, wherein each of the first portions (241) of the adhesive layer and each of the second portions (242) of the adhesive layer have a thickness, measured parallel to the lamination axis (A50), comprised between 15 μm and 30 μm, preferably comprised between 18 μm and 25 μm, preferably equal to 20 μm.

15. A fuel cell (20) comprising: a stack (50) formed from a plurality of single cells (100) stacked along the stacking axis (A50), each single cell being as defined in any one of claims 1 to 14; and a sleeve (24) providing an internal volume (V24) in which the stack is housed, the frames (210) of the sealing structures (200; 300; 400; 500) of each single cell each have a unique outer edge (215) with an associated outer contour; The outer contours of all the frames of each sealing structure are superimposed on one another along the stacking axis (A50), and the outer edges of all the frames of all the sealing structures together form an outer surface (S50) of the stack having a cylindrical shape centered on the stacking axis; a retaining member (52) configured such that the outer surface (S50) of the stack cooperates with a fitting member (30) provided within the internal volume (V24) of the sleeve to maintain the stack (50) within the internal volume and provide a surrounding volume (V50) between the stack (50) and the sleeve (24); A fuel cell (20), wherein the retaining member and the fitting member are designed to divide the surrounding volume (V50) into a plurality of conduits (38A, 38B, 38C) for circulation of the working fluid of the fuel cell.

16. For each compartment (V100) of each single cell (100), the associated compartment frame (330) comprises a transfer frame providing two passages (332) for a fluid, the two passages being provided for circulation of the associated working fluid between the corresponding compartment (V100) and the outside of the single cell (100); Each passage (332) opens into the associated compartment (V100) through an internal port (334) provided in the inner edge (214) of the transfer frame; 16. The fuel cell according to claim 15, wherein each passage (332) opens to the outside of the compartment (V100) through an external port (335).

17. the external port (335) is provided at the outer edge (215) of the transfer frame (330); the fuel cell provides two first pairs of circulation conduits (38A, 38B) associated with the first working fluid and the second working fluid of the fuel cell, respectively; The single cell (100) is according to any one of claims 5 to 14, For each single cell, each of the two compartments (V100) selected from the first reaction compartment (V132) and the second reaction compartment (V134) is associated with a respective pair of the first conduits (38A, 38B); the compartment frames (330; 430; 530) associated with each of the two reaction compartments (V132, V134) of the single cell each comprise a transfer frame (330) each having two passages (332), the external opening (335) of each passage being provided at the outer edge (215) of the corresponding transfer frame; 17. The fuel cell (20) of claim 16, wherein the two passages (332) of the same transfer frame each open into a separate one of the two circulation conduits of the associated pair of conduits.

18. for each single cell (100), the first separator (110) is configured to sealingly separate the first reaction compartment (V132) from a first cooling compartment (V136) configured to receive a third working fluid of the fuel cell; the fuel cell provides, in addition to the two first pairs of circulation conduits (38A, 38B), a third pair of circulation conduits (38C), the third pair of circulation conduits (38C) being associated with the third working fluid; For each single cell, each of the three zones (V100) selected from the first reaction zone (V132), the second reaction zone (V134), and the first cooling zone (V136) is associated with a respective pair of the three pairs of conduits (38A, 38B, 38C); the compartment frames (330; 430; 530) associated with each of the three compartments (V132, V134, V136) of the single cell each comprise a transfer frame (330) each having two passages (332), the external opening (335) of each passage being provided at the outer edge (215) of the corresponding transfer frame; A fuel cell (20) according to any preceding claim, wherein the two passages (332) of the same transfer frame each open into a separate one of the two circulation conduits of the associated pair of conduits.

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