SPACER FOR A WATER ELECTROLYSIS CELL

[0001]Generally speaking, the electrolysis is a technique allowing to carry out non-spontaneous chemical reactions using a direct electric current circulating between two electrodes placed face to face, referred to as the anode and cathode, and separated by an ionically conductive medium referred to as the electrolyte. The electrodes, which may be solid or porous, may be of different types (e.g. plates, sheets, grids). Each of the two half-reactions requires the use of an electro-catalyst configured to maximize their kinetics. The electro-catalysts, generally made of expensive materials, are deposited on the surface of the anode and of the cathode, on the faces in contact with the electrolyte.

[0002]The present invention relates more particularly to the field of water electrolysis, which consists of dissociating the water molecules into gaseous dioxygen and dihydrogen. The dioxygen and the dihydrogen formed by water electrolysis may then be used as consumables in the chemical industry. The water electrolysis reactors take the form of a succession of individual cells, stacked one on top of the other, electrically connected in series and connected in a fluid manner in parallel. The fluids flow tangentially to the plane of each cell. The electric current flows in a direction perpendicular to the plane of the cells. The charge carriers are electrons in the metal phases and ions in the electrolyte. Each individual water electrolysis cell is separated into two compartments, referred to as the anode structure and the cathode structure. The type of separator used depends on the electrolysis technology. For example, there are electrolysis technologies that use a polymer membrane with cationic conduction (conduction by protons) or anionic conduction (conduction by hydroxyl ions) as the separator.. Other technologies use porous thermoplastic separators or ceramic separators.

[0003]A specific example is the electrolysis of liquid water using acid polymer electrolyte technology (PEM stands for proton-exchange membrane or polymer electrolyte membrane). The polymer membrane, which has a typical thickness of between 50 and 250 microns (or micrometers), is a solid electrolyte, with the ionic charge carriers remaining confined within it. The electro-catalysts are deposited on both faces of the membrane. The polymer membrane is therefore coated with two catalytic layers with a typical thickness of between a few micrometers and a few tens of micrometers. The two catalytic layers form the two electrodes of the cell. Such membrane-electro-catalyst assemblies are known as CCM (catalyst-coated membrane). A water electrolysis reactor, for example of the proton exchange membrane type, comprises two liquid water injection wells and two two-phase mixture collection wells. Each compartment of each cell has a water inlet point (liquid or vapor, depending on the technology) supplied by the injection well and an outlet point of reaction mixture (single-phase or two-phase, depending on the technology) connected to the collection well. In the simplest case, the single electrochemical reactor is connected to two separate, closed fluid (electrolyte) circulation circuits: an anode circuit and a cathode circuit. The anode injection well and the anode collection well are connected in a fluid manner to the anode circuit. The cathode injection well and the cathode collection well are connected in a fluid manner to the cathode circuit. The liquid water circulates in each of these two circuits by means of a pump, in an internal gyratory direction from the injection well to the collection well. Each circuit comprises various functional units, for example, a liquid-gas separator for separating and collecting the gases produced by the reaction, a thermal exchanger for extracting the heat produced in the cells during electrolysis, a resin bed for controlling the conductivity of the circulating water, a pump for circulating the water in the circuit, and various pressure, temperature and flow rate sensors for controlling the operation to a control-command machine. There are more complex cases where several reactors are interconnected electrically and in a fluid manner, in series or in parallel, each with an individual or common anode and cathode circuit. In operation, the liquid water is injected by a pump into each compartment of each cell and a two-phase mixture (liquid water and gas generated in the cell during electrolysis) is collected at the outlet of each compartment. A mixture of liquid water and oxygen gas is collected at the outlet of the anode structure and a mixture of liquid water and hydrogen gas is collected at the outlet of the cathode structure. The flow of liquid water which pass through the anode structure of each cell serves both to fuel the electrolysis reaction and to cool the anode structure, as the oxygen release reaction is exothermic. The flow of liquid water which pass through the cathode structure of each cell serves both to collect the electro-osmotic water which pass through the membrane and to cool the cathode, as the hydrogen evolution reaction is exothermic.

[0004]The invention relates firstly to a spacer for a water electrolysis cell configured to support a separator, comprising at least one inlet and one outlet configured to allow a circulation of water within the water electrolysis cell, the spacer comprising a recess configured to be occupied by the separator and in fluid communication with the inlet and the outlet, the spacer further comprising at least one dispensing area connecting either the inlet or the outlet to the recess, innovative in that the dispensing area comprises at least one laminar flow member extending along an edge of the recess.

[0005]The present invention essentially concerns a frame, preferably made of an injectable thermoplastic material, of small thickness, for example a few millimeters, recessed in the middle, of preferably square or rectangular geometric shape, pierced with preferably circular holes to allow the circulation of the fluids, equipped with injectors and collectors allowing the fluid to enter the injection well in the cell compartment and the reaction fluids to leave the cell compartment in the collection well, equipped with several seals to ensure the fluid sealing between the inside of the reactor and the outside, and comprising an assembly of studs or teeth configured to ensure a homogeneous dispensing of the flowing fluids in each compartment of each cell. The difficulty for the person skilled in the art consists in ensuring, at every point of each compartment of each cell of the water electrolysis reactor, a homogeneous and constant flow rate of water, so as to correctly supply and cool each electrode of each compartment of each cell.

[0006]When no special precautions are taken to control the fluid distribution in the cell compartments, the dispensing of water within each cell and also from one cell to another is not optimal, i.e. the flow of water passing through each compartment of each cell is heterogeneous and varies from one place to another. For example, in the case of a rectangular spacer equipped with an inlet point at one of its four corners and an outlet point diagonally opposite, the flow of water will tend to circulate along the shortest hydraulic path (the one with the lowest hydraulic resistance), i.e. along the diagonal of the spacer. In this case, the water is not distributed uniformly over the active electrochemical surface, resulting in heterogeneous operation, a loss of energy efficiency and an accelerated ageing of the reactor. In addition, the flow of water along the shortest path is rapid, which tends to create hydraulic turbulence, further disrupting the operation.

[0007]The present invention describes a spacer which allows to overcome these problems, and in particular to ensure a homogeneous water circulation at every point in each compartment of each cell of a water electrolysis module. The homogeneous water circulation also indirectly helps to ensure a good operation of the electrolysis cells as a whole, by controlling injection pressure drops. Such a water electrolysis cell spacer is also designed to accommodate a separator, for example a polymer electrolysis membrane.

[0008]The spacer may be made of different materials, for example thermoplastic materials for “low temperature” applications, such as a proton exchange membrane cell, an anion exchange membrane cell or an alkaline electrolysis cell.

[0009]The spacer according to the invention is a frame preferably made of thin injectable thermoplastic material, preferably square or rectangular in shape, comprising at least one inlet and one outlet allowing water to circulate within the water electrolysis cell.

[0010]Advantageously, the inlet may comprise a fluidic injector and an injection well, and the outlet may comprise a collection well and a fluidic collector. The spacer is recessed at its center and has a peripheral support equipped with a seal on which the separator is pressed so as to separate the cell into two distinct compartments, anode and cathode. The recess of the spacer is in fluid communication with the anode and cathode circuits. The fluidic injector connects the inlet of the injection well to the fluidic dispensing area, possibly one per compartment, and at least one fluidic collector connecting at the outlet the fluidic dispensing area to the collection well. The spacer is characterized in that the fluid dispensing area comprises at least one laminar flow member extending along an edge of the recess, i.e. along one of the inner sides of the spacer in fluid contact with the central recess.

[0011]The laminar flow member generates a plurality of straight streams of water.

[0012]In addition, the space in each compartment located between the inlet and outlet laminar flow members comprises a metal grid, the purpose of which is to ensure the electrical contact perpendicular to the plane of the individual cells and also to create a fluidic pressure drop that will also contribute to the paralleling of the water streams circulating in the compartment of the cell.

[0013]Thanks to this assembly of fluidic and mechanical characteristics, the spacer which is the subject of the invention will allow the flows of water circulating in the two compartments of each elementary cell to flow homogeneously along the active surface of each compartment, which ensures a homogeneous operation and thus prolongs the service life of the electrolysis cell while maximizing the energy efficiency of the reactor. The spacer, object of the invention, also ensures the same level of fluid homogeneity in each compartment of each cell of an electrochemical reactor, whatever their number. The characteristics of the spacer are independent of its size. The spacer has fluidic, mechanical and dimensional characteristics adapted to the size of the electrolysis cell.

[0014]The recess at the inlet to each cell compartment faces the active surface of the cell. After entering the cell compartment, the laminar flow of water flows along this recess and cools the active surface of the cell evenly, for example the surface of one of the electrodes. Such cooling takes place by heat exchange, so the temperature of the water rises as it flows along the recess. The heated water flow then exits the cell via the outlet located opposite the inlet point.

[0015]The fluid dispensing area is arranged between the inlet and the recess and/or between the recess and the outlet. It is within the dispensing area that the flow rate of water is homogenized, thanks in particular to the laminar flow member. This is positioned as close as possible to the recess. For example, when the dispensing area is arranged between the inlet and the recess, the laminar flow member is arranged along the edge of the recess corresponding to the edge through which the water enters the recess. This ensures a laminar flow of water is formed directly on entering the recess.

[0016]According to a characteristic of the invention, the laminar flow member comprises a plurality of teeth spaced apart to form channels configured to implement a rectilinear flow of water streams. In other words, the channels are formed between two separate teeth. The channels are small in order to create a pressure drop that contributes to the even distribution of the water flow rate along the injection channel. A channel is formed by two adjacent teeth with sides preferably parallel or substantially parallel to each other. The teeth obstruct the flow of water and force it to circulate within the channels, to initiate parallel fluid lines in the compartments. The flow of water from the inlet and/or the recess is therefore distributed across the various channels and emerges from the latter as a laminar flow. Advantageously, at least some of the channels are configured to be oriented parallel to a direction of flow of the water flow. Even more advantageously, the assembly of the channels is oriented parallel to the direction of flow of the water flow in order to increase its homogeneity after passing through the laminar flow member. In this configuration, the laminar flow member is shaped like a comb.

[0017]According to a characteristic of the invention, the teeth of the laminar flow member are configured to provide a resistance against support at the level of the laminar flow member. As well as ensuring a laminar flow of water, the teeth provide a mechanical resistance perpendicular to the plane of the spacer that is compatible with the stacking of several cells in series, potentially up to several dozen or even several hundred. For example, it is the height of the tooth that ensures the required resistance. An electrolysis cell is integrated into an electrolysis module comprising several electrolysis cells stacked one on top of the other. The spacer according to the invention is therefore integrated into this stack and is therefore pressed against at least one adjacent support. The mechanical properties of the teeth, in particular their rigidity and their resistance to deformation, are such that said teeth are not deformed by the support resulting from the stacking, thus allowing to keep the channels intact and operational to make the flow of water laminar when the reactor is closed and compressed to ensure the sealing of the cells. The support opposite the laminar flow member also helps to delimit a passage section for the channels.

[0018]In accordance with a characteristic of the invention, the dispensing area comprises a dispensing chamber extending between either the inlet or the outlet and the laminar flow member. The dispensing chamber helps to dispense the flow of water to the entire laminar flow member, i.e. along the edge of the recess. The dispensing chamber ensures that the flow subsequently circulates over the entire surface of the recess, so that the local water flow rate is homogeneous and the electrode is cooled evenly over its entire surface.

[0019]According to one characteristic of the invention, the dispensing chamber comprises a plurality of deflection members. The deflection members may be of various shapes, the main thing being that they obstruct the flow of water so that it is correctly dispersed throughout the entire dispensing chamber, and then flows through each channel of the flow member, in laminar flow and as uniformly as possible.

[0020]According to a characteristic of the invention, the plurality of deflection members is configured to provide a resistance against a support at the level of the dispensing chamber. Like the teeth of the laminar flow member, the deflection members are not deformed when they are pressed against the dispensing chamber during the stacking. Spaces are kept within the dispensing chamber so that the water may always circulate and be correctly dispensed.

[0021]According to a characteristic of the invention is that at least one deflection member is oblong. An elongated deflection member further guides the flow of water in a preferred direction. For example, the oblong deflection members may have a main direction parallel to the flow of water to promote its laminarity. The oblong deflection members may also have a main direction perpendicular to the flow of water in order to make the latter circulate, at least partially, towards the portions of the dispensing chamber furthest away from the inlet or recess, and thus promote the homogeneity of the flow of water.

[0022]According to a characteristic of the invention, the recess is rectangular in shape and has two longitudinal edges and two lateral edges, the laminar flow member being arranged along one of the longitudinal edges. The longitudinal edges are parallel in pairs, as are the lateral edges. The laminar flow member is arranged so that the flow of water passes through the recess from one longitudinal edge to the other. This configuration allows the flow of water to pass through the recess in the smallest dimension. This ensures that the water flow is not overheated when exchanging heat with the electrode opposite the recess.

[0023]According to a characteristic of the invention is that the inlet and the outlet lie between two straight lines passing through the lateral edges. In other words, the dispensing chamber is interposed between the laminar flow member and the inlet or the outlet, in a lateral direction defined by the side edges of the recess.

[0024]According to a characteristic of the invention, the inlet and the outlet are arranged symmetrically with respect to a central point of said spacer. For example, if the inlet is centered with respect to the longitudinal edges, then the outlet is also centered with respect to the longitudinal edges. If the input is offset in the longitudinal direction from the center of the longitudinal edges, then the output is also offset in the longitudinal direction from the center of the longitudinal edges, but in the opposite direction to the input offset. In such a configuration, a segment extending between the inlet and the outlet has an oblique direction with respect to the longitudinal edges and with respect to the lateral edges of the recess.

[0025]According to a characteristic of the invention, the dispensing area is a first dispensing area, the spacer comprising a second dispensing area at least partially symmetrical to the first dispensing area with respect to a median axis of the recess. The median axis is parallel to the direction of the longitudinal edges. The spacer thus comprises two dispensing areas, one between the inlet and the recess, and one between the recess and the outlet. Each of the dispensing areas thus comprises a first laminar flow member and a second laminar flow member extending along the longitudinal edge delimiting its own dispensing area. The first dispensing area also comprises a first dispensing chamber extending between the inlet and the first laminar flow member, while the second dispensing area comprises a second dispensing chamber extending between the second laminar flow member and the outlet.

[0026]In accordance with a characteristic of the invention, the spacer comprises a first face and a second face, the spacer comprising an intake and an evacuation configured to allow a circulation of water within the water electrolysis cell, the spacer further comprising at least one distribution area connecting either the intake or the evacuation to the recess, the dispensing area being formed in a thickness of the spacer by opening onto the first face while the distribution area is formed in a thickness of the spacer by opening onto the second face. The recess inside the spacer is split in two compartments, namely an anode structure and a cathode structure, separated by a separator.

[0027]The first face comprises the inlet, one or more dispensing chambers and the outlet. The second face comprises the intake, one or more distribution chambers and the evacuation.

[0028]The operation of the spacer on the second face is identical to the operation of the spacer on the first face, i.e. the use of means to distribute and homogenize a flow of water to cool one of the electrodes. However, the structural characteristics of the elements on each face may vary depending on the cooling conditions and/or cooling objectives.

[0029]According to a characteristic of the invention, the distribution area comprises at least one laminar flow device extending along an edge of the recess. The function of the laminar flow device is identical to that of the laminar flow member on the first face, i.e. to homogenize the flow of water circulating within the distribution area.

[0030]The invention also covers a water electrolysis cell comprising an anode structure, a cathode structure and a separator interposed between the anode structure and the cathode structure, the water electrolysis cell comprising a spacer as previously described, said spacer supporting the anode structure, the cathode structure and the separator. Supplied by an electric current, the electrolysis cell forms dihydrogen and dioxygen from water. The spacer helps to ensure homogeneously and equitably distributed cooling over the assembly of at least one surface of at least one of the electrodes of the electrolysis cell.

[0031]The invention also covers a water electrolysis module comprising a plurality of electrolysis cells as described above, the electrolysis cells being stacked on top of the other. Other characteristics and advantages of the invention will become apparent from the following description, on the one hand, and from a number of examples of embodiment given by way of indication and without limitation with reference to the attached schematic drawings, on the other hand, wherein:

[0032]FIG. 1 is a schematic diagram showing an exploded view of a water electrolysis cell comprising a spacer according to the invention,

[0033]FIG. 2 is a view of a first face of the spacer,

[0034]FIG. 3 is a view of a second face of the spacer, opposite the first face,

[0035]FIG. 4 is a sectional view of a portion of the spacer,

[0036]FIG. 5 is a diagram of an electrolysis module.

[0037]FIG. 1 shows an electrolysis cell 1, in particular an exploded sectional view showing the stack of elements inside the electrolysis cell 1. A direct electric current flows through the electrolysis cell 1, breaking down the water into oxygen and hydrogen.

[0038]The electrolysis cell 1 comprises a separator 2 interposed between an anode structure 3, generally made of titanium, and a cathode structure 4, generally made of titanium but which may contain carbon elements, which are connected directly or indirectly to the positive and negative terminals of an external DC electrical generator, not shown. For example, the separator 2 may be a membrane-electro-catalyst assembly if the electrolysis cell is a proton exchange membrane cell or an anion exchange membrane cell. In the case of an alkaline electrolysis cell, the separator is a diaphragm.

[0039]Generally speaking, the invention may also be applied to other types of cells, such as the solid oxide electrolysis cells.

[0040]The anode structure 3 comprises a bipolar plate 31 in common with an upper adjacent cell, an anode grid 32 and an anode porous element 33 generally consisting of titanium particles or fibers sintered together in a vacuum. The anode structure 3 may also comprise attachment means 34 adapted to the shape of the electrolysis cell 1, allowing the bipolar plate 31, the grid 32 and the porous element 33 to be attached. These three elements of the anode structure 3 allow to optimize the electrical conduction and mechanical resistance and contribute to a good fluid dispensing. The cathode structure 4 also comprises a second bipolar plate 41 in common with a lower adjacent cell, a cathode grid 42 and a cathode porous element 43 of the same nature as the anode porous element 33 or made of carbon, all these elements having the same properties as the elements integrated into the anode structure 3. When the electrolysis cell 1 is in operation, i.e. with direct current passing through it, the electrolysis cell 1 gives off heat. The anode structure 3 and the cathode structure 4 are heated by Joule effect, as is the polymer membrane of the separator 2 due to its ionic conduction. The catalytic layers of the separator 2 also generate heat. The electrolysis cell 1 must therefore be cooled continuously so as to maintain its temperature below a maximum value, which depends on the chemical nature of the membrane of the separator 2, typically below 100° C., in order to prolong its service life and prevent a premature damage. To do this, a water circuit (not shown) allows water to circulate through at least the anode structure or the cathode structure in order to cool it or them. The electrolysis cell 1 also comprises a spacer 5 supporting the separator 2 in its middle. The anode structure 3 and the cathode structure 4 fit into a recess in the center of the spacer 5. The bipolar plates 31 and 41 cover the spacer 5 and hold the elements of the anode structure 3 and of the cathode structure 4 in place and in contact with each other. In this way, the porous anode 33 and cathode 43 elements are in contact with the catalytic layers of the separator 2. The spacer 5 also contributes to the circulation of water in each of the two compartments, in order to supply the reaction with water and ensure the cooling of the electrodes, as will be described in detail later. The electrolysis cell 1 may also rest on a support plate 6.

[0041]FIG. 2 is a representation of the spacer 5 seen from above, i.e. seen in a direction perpendicular to the plane of the electrolysis cell 1. This is a view of the anode face. More specifically, FIG. 2 shows a first face 51 of the spacer 5, in this case the anode face of the spacer.

[0042]The spacer 5 is a parallelepipedal solid element with a square or rectangular base. The main plane extends in a first direction referred to as the longitudinal direction L1 and in a second direction referred to as the lateral direction L2.

[0043]The thickness of the frame extends in a direction perpendicular to the main plane. The spacer 5 comprises two through-orifices, a fluid inlet 7 and a fluid outlet 8. Preferably, in the electrolysis cell 1, the inlet 7 comprises a fluid injector and an injection well, and the outlet 8 comprises a collection well and a collector, for example geometrically opposite the fluid injector. In an electrolysis reactor consisting of a stack of several individual electrolysis cells as shown in FIG. 1, the stack of spacers 5 forms the injection and collection wells. The water circulating in the injection well penetrates the structure of the spacer 5. The two-phase mixture, i.e. a mixture of water and oxygen or hydrogen, then leaves the compartment of the spacer 5 and reaches the collection well making up the outlet 8. The inlet 7 and its injector and the outlet 8 and its collector respectively ensure the inlet of water and the outlet of the two-phase mixture. The inlet 7 and the outlet 8 therefore allow water to flow in and out of the electrolysis cell to supply and cool the latter.

[0044]The spacer 5 also comprises the recess 9, shown in FIG. 1, which is configured to be filled in particular by the separator and by the anode and cathode structures of the electrolysis cell. Thus, when water enters and circulates within the electrolysis cell, it flows parallel to the main plane, formed by the longitudinal direction L1 and the lateral direction L2 of the separator, with the recess 9 being in fluid communication with both the inlet 7 and the outlet 8. The spacer 5 also comprises at least one dispensing area 10 interposed between the recess 9 and either the inlet 7 or the outlet 8. The dispensing area 10 provides a fluid connection between the inlet 7 and the recess 9, or between the recess 9 and the outlet 8. In FIG. 2, the spacer 5 comprises a first dispensing area 11 arranged between the inlet 7 and the recess 9, and a second dispensing area 12 arranged between the recess 9 and the outlet 8. The first dispensing area may be referred to as the input dispensing area, while the second dispensing area may be referred to as the output collection area.

[0045]Although FIGS. 2 and 3 show a symmetry between the inlet and the outlet of the same cell, an asymmetry in size and geometry is also possible. This is because, during the reaction, the volume of the gases produced increases. The cross-section of the well may be different, as shown in FIG. 2 and FIG. 3. This difference in cross-section is implemented in order to accommodate the difference in flow rate between the two compartments, as there is more water flow rate circulating in the anode circuit than in the cathode circuit. It is therefore possible to adapt the diameter of the wells within the same compartment to accommodate the increase in volume flow rate induced by the formation of gas during the reaction. It is also possible to imagine a geometric difference between the two to facilitate the evacuation of the gas bubbles. In other words, the invention also relates to a spacer wherein the wells and/or the dispensing/distribution areas may be of different size and geometry at the inlet and outlet.

[0046]The second dispensing area 12 is at least partially symmetrical to the first dispensing area 11 with respect to a median axis 13 of the recess 9, said median axis 13 being parallel to the longitudinal direction L1. The special characteristic of the spacer 5 according to the invention is that the dispensing area 10, whether the first dispensing area 11 or the second dispensing area 12, comprises a laminar flow member 14 extending along one edge of the recess 9. On the FIG. 2, the first dispensing area 11 comprises a first laminar flow member 15 while the second dispensing area 12 comprises a second laminar flow member 16. The role of the laminar flow members 14 is to homogenize the flow of water circulating within the electrolysis cell by paralleling the streams of water forming the flow of water circulating between the inlet 7 and the outlet 8. This reduces turbulence in the water flow and ensures it circulates evenly, contributing to a greater cooling efficiency. The recess 9 has an overall rectangular shape comprising two longitudinal edges 17 and two side edges 18 parallel in pairs. More specifically, the recess 9 comprises a first longitudinal edge 17a corresponding to the longitudinal edge 17 closest to the inlet 7, and a second longitudinal edge 17b corresponding to the longitudinal edge 17 closest to the outlet 8. The side edges 18 are perpendicular to the longitudinal edges 17. The spacer 5 is arranged so that the water circulates parallel to the lateral direction L2 so as to circulate over the shortest possible distance along the electrolysis cell, the aim being that the water does not reach too high a temperature at the outlet in order to protect the separator, which has a limited thermal stability, and to ensure a uniform flow of the current along a direction parallel to the thickness of the spacer 5, through the electrolysis cell. Thus, the first laminar flow member 15 extends along the first longitudinal edge 17a, preferably over the whole of the first longitudinal edge 17a, while the second laminar flow member 16 extends along the second longitudinal edge 17b, preferably over the whole of the first longitudinal edge 17b. Each laminar flow member 14 comprises teeth 29 defining channels 19, a channel 19 being delimited by two adjacent teeth 29. It is by circulating through these channels 19 that the water streams forming the water flow circulate parallel to each other. Preferably, at least some of the channels 19 have a main direction parallel to the lateral direction L2, i.e. the direction of flow of the cooling water flow. More preferably, the assembly of the channels 19 are parallel to the lateral direction L 2. The laminar flow member 14 then has a comb shape, the geometry of which is optimized as a function of the hydraulic flow passing through the electrolysis cell so as to satisfy the constraint imposed on the maximum outlet temperature. In one example, the combs forming the laminar flow member 14, 16 may have a different hydraulic diameter. Each dispensing area 10 also comprises a dispensing chamber 20 extending between any of the inlet 7 and outlet 8 at one of the laminar flow members 14. In FIG. 2, the first dispensing area 11 comprises a first dispensing chamber 21 located between the inlet 7 and the first laminar flow member 15. The second dispensing area 12 comprises a second dispensing chamber 22 located between the second laminar flow member 16 and the outlet 8. The length of the first dispensing chamber 21 and the second dispensing chamber 22 may be adjusted according to the hydraulic flow passing through the cell so as to satisfy the constraint imposed on the maximum outlet temperature. Thus, according to the configuration of the spacer 5 shown in FIG. 2, the water used to operate and cool the electrolysis cell enters the cell via the inlet 7, then passes through the first dispensing chamber 21, the first laminar flow member 15, and then through the recess from the first longitudinal edge 17a to the second longitudinal edge 17b. On leaving the recess 9, the two-phase mixture passes through the second laminar flow member 16, then the second dispensing chamber 22 before leaving the electrolysis cell to return to the outlet 8. The first dispensing chamber 21 and the second dispensing chamber 22 are formed in one thickness of the spacer 5, opening onto the first face 51. Each dispensing chamber 20 may comprise a plurality of deflection members 23 configured to obstruct the flow of water circulating from the inlet 7 to the outlet 8. The deflection members 23 allow the flow to be evenly dispensed to the assembly of the channels 19. Preferably, the deflection members 23 are shaped to homogenize and/or guide the flow of water, in particular to parallelize the streams of water passing through the electrolysis cell. In the vicinity of the inlet 7 or of the outlet 8, the deflection members 23 have an oblong shape extending mainly parallel to the circulation of the flow of water, in order to ensure at least a partial homogenization when the flow of water enters the first dispensing chamber 21, or before leaving the spacer 5. Each dispensing chamber 20 may also comprise other oblong deflection members 23 extending mainly perpendicular to the circulation of the flow of water. These deflection members 23 ensure a dispensing of the water to the portions of the first dispensing chamber 21 furthest from the inlet 7. Thanks to the deflection members 23 in the first dispensing chamber 21 and the channels 19 in the first laminar flow member 15, the flow of water is laminar and evenly dispensed along the electrode to be cooled, guaranteeing an optimum cooling capacity. Preferably, the inlet 7 and the outlet 8 are arranged symmetrically with respect to a central point Y of the spacer 5. In FIG. 2, the inlet 7 and the outlet 8 are offset from each other in the longitudinal direction L1 and in the opposite direction to each other. It is also possible to arrange the inlet 7 and the outlet 8 both centered in relation to the longitudinal edges 17. However, the inlet 7 and the outlet 8 are positioned so that they lie between two straight lines Z1, Z2 passing through the side edges 18.

[0047]The spacer 5 also comprises a sealing member 24 extending around the inlet 7, the outlet 8, the dispensing areas 10 and the recess 9. The sealing member 24 prevents water leaks and ensures that the flow of water is as described above. The spacer 5 also comprises an internal seal, located under each longitudinal edge 17 and each lateral edge 18, to prevent the water infiltrations between said edges and the separator.

[0048]FIG. 2 also shows that the spacer 5 comprises also an intake 25 and an evacuation 26 which are, however, outside the sealing member 24 and are therefore not connected in a fluid manner to the assembly of the aforementioned elements, but which serve to ensure the circulation of water along a face opposite the first face 51 of the spacer 5.

[0049]FIG. 3 shows a second face 52 of the spacer 5, corresponding to the opposite face of the first face 51 described in FIG. 2. It is at the level of the second face 52 where the intake 25 and the evacuation 26 are connected in a fluid manner. It is thus understood that a first flow of water circulating along the first face 51 ensures the cooling of one of the compartments of the electrolysis cell, while a second flow of water circulating along the second face 52 ensures the cooling of the other compartment of the electrolysis cell. For example, the first face 51 corresponds to the face on the anode structure face, while the second face 52 corresponds to the face on the cathode structure face. When the spacer 5 comprises two faces 51, 52 as illustrated in FIGS. 2 and 3, said spacer 5 then comprises at least one distribution area 60, in this case a first distribution area 61 and a second distribution area 62, which is the equivalent of the dispensing area described in FIG. 2. Each distribution area 60 comprises a distribution chamber 63 and a laminar flow device 64 which are respectively equivalent to the dispensing chamber and the laminar flow member described in FIG. 2. Like the laminar flow member, the laminar flow device 64 extends along the longitudinal edge 17 of the recess 9 and comprises a plurality of teeth 29 delimiting channels 19 which implement a rectilinear flow of streams of water, in order to homogenize the flow of water. On the other hand, the distribution chambers 63 only comprise oblong deflection members 23 extending mainly in the direction of circulation of the water flow and located close to the intake 25 or to the evacuation 26 and allowing to homogenize the water flow at the outlet of the intake 25 or upstream of the evacuation 26. As the intake 25 and the evacuation 26 have a smaller opening than the inlet 7 and the outlet 8, the second flow of water circulating along the second face 52 is at a higher pressure than the first flow of water circulating along the first face. The higher pressure of the second water flow is therefore sufficient to distribute the water throughout the assembly of the channels 19 of the laminar flow device 64 without the need for deflection members 23 to ensure such a distribution. The spacer 5 comprises a sealing device 65 with the same function as the sealing member illustrated in FIG. 2. Unlike the sealing member, the sealing device 65 extends in particular around the intake 25 and the evacuation 26 and excludes the inlet 7 and the outlet 8 so that the flow of water circulating along the second face 52 circulates between the intake 25 and the evacuation 26 passing through the distribution area or areas 60 and circulating along the recess 9. With the exception of the characteristics described above and in relation to FIG. 3, reference is made to the description in FIG. 2 concerning the structural and functional characteristics common to both faces 51, 52 of the spacer 5.

[0050]FIG. 4 shows a cross-sectional view of the spacer, more particularly of the first face 51 and of the second face 52 at the level of the laminar flow member 14 and of the laminar flow device 64. The sealing member 24 and the sealing device 65 are also partially visible. As described previously, the laminar flow member 14 and the laminar flow device 64 each comprise teeth 29 delimiting channels 19. In addition to the function of delimiting the channels 19, the teeth 29 also have a mechanical resistance allowing them to withstand a pressure 28 exerted on the spacer, for example a first pressure 28a exerted on the first face 51 and a second pressure 28b exerted on the second face 52. An electrolysis cell is made up of a plurality of elements stacked and pressed against each other. The supports 28 are therefore pressed against the spacer, and the teeth 29 on each face 51, 52 of the spacer hold them mechanically. So, once the assembly of the electrolysis cell is stacked, the channels 19 are closed without being obstructed, and the water circulation may take place. Although FIG. 4 illustrates supports exerted on the laminar flow member 14 and on the laminar flow device 64, similar supports are also implemented in the dispensing chamber and the distribution chamber. In such a configuration, it is the deflection members that provide the mechanical resistance to maintain the circulation of water despite the pressure exerted by such supports. FIG. 5 illustrates a water electrolysis module 70 consisting of a plurality of electrolysis cells 1 stacked one on top of the other in a stacking direction E, perpendicular to the main plane mentioned above. The electrolysis module 70 thus comprises as many electrolysis membranes, anode compartments and cathode compartments as there are electrolysis cells 1. The electrolysis module 70 comprises a first incoming duct 71 which connects, for example, to the inlet of the spacer inside the reactor and a second incoming duct 72 which connects to the intake of the spacer inside the reactor. The first incoming duct 71 and the second incoming duct 72 ensure that water enters the electrolysis module 70. More specifically, the first incoming duct 71 allows water to enter and configured to interact with the assembly of the anode compartments of the electrolysis module 70, for example to cool them and/or to supply the water electrolysis reaction. The second incoming duct 72 allows an inlet of water configured to interact with the assembly of the cathode compartments of the electrolysis module 70, for example to cool them and/or to supply the water electrolysis reaction. Each inlet duct 71, 72 therefore comprises several outlet orifices, each allowing water to circulate near the anode and cathode compartments depending on the inlet duct 71, 72 in question. The electrolysis module 70 also comprises a first outgoing duct 73 which connects with the spacer outlet inside the reactor and a second outgoing duct 74 which connects with the spacer evacuation inside the reactor, both also extending mainly in the stacking direction E. The first outgoing duct 73 allows the two-phase water-oxygen mixture produced inside the anode compartments of the reactor to be collected after the water has circulated close to the anode catalytic layers of the electrolysis module 70.

[0051]The second outgoing duct 74 is used to collect the two-phase water-hydrogen mixture produced inside the cathode compartments of the reactor after the water has circulated close to the cathode catalyst layers of the electrolysis module 70.

[0052]In order to ensure that the electrolysis cells 1 are stacked and sealed within the electrolysis module 70, the latter also comprises a plurality of attachment means 75 allowing the electrolysis cells 1 to be pressed against each other in the stacking direction E.

[0053]Of course, the invention is not limited to the examples just described and numerous adjustments may be made to these examples without going beyond the scope of the invention.

[0054]The invention, as just described, achieves its intended purpose and allows to offer a spacer for an electrolysis cell which ensures a homogeneous fluid dispensing over the assembly of said electrolysis cell. Non described variants herein may be implemented without leaving the context of the invention, provided that, in accordance with the invention, they comprise a spacer in accordance with the invention.