Spacer for a water electrolysis cell

Abstract

The present invention relates to a spacer (5) for a water electrolysis cell, the spacer being configured to support a separator and comprising at least one inlet (7) and one outlet (8) configured to allow water to flow within the water electrolysis cell, the spacer (5) comprising a cavity (9) which is intended to be occupied by the separator and is in fluid communication with the inlet (7) and the outlet (8), the spacer (5) further comprising at least one distribution region (10) that connects either one of the inlet (7) or of the outlet (8) to the cavity (9), characterised in that the distribution region (10) comprises at least one laminar flow member (14) that runs along an edge (17, 18) of the cavity (9). The invention also relates to an electrolysis cell comprising such a spacer (5).

Description

[0001] DESCRIPTION

[0002] Title of the invention: Spacer for water electrolysis cell

[0003] Generally speaking, electrolysis is a technique for carrying out non-spontaneous chemical reactions using a direct electric current flowing between two electrodes placed face to face, called anode and cathode, and separated by an ionically conductive medium called electrolyte. The electrodes, which can be solid or porous, can be of different types (e.g. plates, sheets, grids). Each of the two half-reactions requires the use of an electro-catalyst designed to maximize their kinetics. Electro-catalysts, generally made of expensive materials, are deposited on the surface of the anode and the cathode, on the faces in contact with the electrolyte.

[0004] The present invention relates more particularly to the field of water electrolysis, which consists of dissociating water molecules into gaseous oxygen and hydrogen. The oxygen and hydrogen formed by water electrolysis can then be used as consumables in the chemical industry. Water electrolysis reactors are in the form of a succession of individual cells, stacked on top of each other, electrically connected in series and fluidically connected 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 the electrons in the metallic phases and ions in the electrolyte. Each individual water electrolysis cell is separated into two compartments, called the anodic structure and the cathodic structure. The nature of the separator used depends on the electrolysis technology.For example, there are electrolysis technologies that use a cationic conduction (conduction by protons) or anionic conduction (conduction by hydroxyl ions) polymer membrane as a separator. There are other technologies that use porous thermoplastic separators or ceramic separators.

[0005] Consider, as a specific example, the case of the electrolysis of liquid water using the so-called acid polymer electrolyte technology (known by the acronym PEM, which 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 inside. The electrocatalysts are deposited on each of the two faces of the membrane. The polymer membrane is therefore coated with two catalytic layers having 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-electrocatalyst assemblies are called 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) fed by the injection well and a reaction mixture outlet point (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 and closed fluid (electrolyte) circulation circuits: an anode circuit and a cathode circuit. The anode injection well and collection well are fluidically connected to the anode circuit. The cathode injection well and collection well are fluidically connected to the cathode circuit.Liquid water circulates in each of these two circuits using a pump, in an internal rotary direction going from the injection well to the collection well. Each circuit has different functional blocks, for example, a liquid-gas separator which allows the separation and collection of gases resulting from the reaction, a heat exchanger which allows the extraction of the heat produced in the cells during electrolysis, a resin bed which allows the conductivity of the circulating water to be controlled, a pump which ensures the circulation of water in the circuit, and various pressure, temperature and flow sensors which allow the operation to be controlled by a control-command automaton. There are more complex cases where several reactors are electrically and fluidically interconnected, in series or in parallel, each of them having an individual or common anode and cathode circuit.In operation, liquid water is injected using 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 passing through the anode structure of each cell serves both to fuel the electrolysis reaction and to cool the anode structure because the oxygen evolution reaction is exothermic. The flow of liquid water passing through the cathode structure of each cell serves both to collect the electroosmotic flow of water passing through the membrane and to cool the cathode because the hydrogen evolution reaction is exothermic.

[0006] The invention firstly covers a spacer of a water electrolysis cell configured to support a separator, comprising at least one inlet and one outlet configured to allow circulation of water within the water electrolysis cell, the spacer comprising a recess intended to be occupied by the separator and in fluid communication with the inlet and the outlet, the spacer further comprising at least one distribution zone connecting any one of the inlet or the outlet to the recess, innovative in that the distribution zone comprises at least one laminar flow member extending along an edge of the recess.

[0007] The present invention essentially relates to a frame preferably made of injectable thermoplastic material, of low thickness, for example a few millimeters, hollowed out in its middle, of geometric shape preferably square or rectangular, pierced with holes preferably circular to allow the circulation of fluids, equipped with injectors and collectors allowing the entry of the fluid from the injection well into the cell compartment and the exit of the reaction fluids from the cell compartment into the collection well, equipped with several seals making it possible to ensure fluid tightness between the interior of the reactor and the exterior, and comprising a set of studs or teeth intended to ensure a homogeneous distribution of the flowing fluids in each compartment of each cell.Indeed, the difficulty for those skilled in the art consists in ensuring, at every point in each compartment of each cell of the water electrolysis reactor, a homogeneous and constant flow of water, so as to correctly supply and cool each electrode of each compartment of each cell. When no particular precautions are taken to control the fluid distribution in the compartments of the cells, the distribution of water inside each cell but also from one cell to another is not optimal, that is to say that 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 with an inlet point on one of its four corners and an outlet point diagonally opposite, the water flow will tend to flow 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 electrochemically active surface, resulting in heterogeneous operation, loss of energy efficiency, and accelerated aging of the reactor. In addition, the water flow along the shortest path is fast, which tends to create hydraulic turbulence, further disrupting operation.

[0008] The present invention describes a spacer which makes it possible to address these problems, and in particular to ensure homogeneous water circulation at all points in each compartment of each cell of a water electrolysis module. The homogeneity of the water circulation also makes it possible, indirectly, to ensure the proper functioning of the electrolysis cells as a whole, by controlling injection pressure losses. Such a water electrolysis cell spacer is further designed to be able to house a separator, for example a polymer electrolysis membrane.

[0009] The spacer can be made of different materials, for example thermoplastic materials for so-called "low temperature" applications, as is the case of a proton exchange membrane type cell or an anion exchange membrane type cell or an alkaline electrolysis type cell.

[0010] 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.

[0011] Advantageously, the inlet may comprise a fluid injector and an injection well, and the outlet may comprise a collection well and a fluid collector. The spacer is hollowed out in its center and has a peripheral support provided with a seal onto which the separator is pressed so as to separate the cell into two separate compartments, anode and cathode. The recess of the spacer is in fluid communication with the anode and cathode circuits. The fluid injector connects the injection well at the inlet to the fluid distribution zone, possibly one per compartment, and at least one fluid collector connecting the fluid distribution zone to the collection well at the outlet.The spacer is characterized in that the fluid distribution zone 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.

[0012] The laminar flow member generates a plurality of straight streams of water.

[0013] Furthermore, the space of each compartment located between the inlet and outlet laminar flow members includes a metal grid whose role is to ensure electrical contact perpendicular to the plane of the individual cells and also to create a fluid pressure drop which will also contribute to the parallelization of the water streams circulating in the cell compartment.

[0014] Thanks to this set of fluidic and mechanical characteristics, the spacer that is the subject of the invention will allow the water flows circulating in the two compartments of each elementary cell to flow homogeneously along the active surface of each compartment, which ensures homogeneous operation and thus prolongs the service life of the electrolysis cell while maximizing the energy efficiency of the reactor. The spacer that is the subject of the invention also makes it possible to ensure the same level of fluidic homogeneity in each compartment of each cell of an electrochemical reactor, regardless of their number. The characteristics of the spacer are independent of its size. The spacer in fact has fluidic, mechanical and dimensional characteristics adapted to the size of the electrolysis cell.

[0015] The recess at the inlet of each cell compartment is arranged opposite the active surface of the cell. After entering the cell compartment, the laminar water flow flows along this recess and thus uniformly cools the active surface of the cell, for example the surface of one of the electrodes. Such cooling is achieved by heat exchange and the temperature of the water therefore increases as it flows along the recess. The heated water flow then exits the cell via the outlet located opposite the entry point.

[0016] The fluid distribution zone is arranged between the inlet and the recess and / or between the recess and the outlet. It is within the distribution zone that the water flow is homogenized, in particular thanks to the laminar flow member. This is arranged as close as possible to the recess. For example, when the distribution zone 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 makes it possible to have a laminar flow of water formed directly upon entering the recess.

[0017] According to a characteristic of the invention, the laminar flow member comprises a plurality of teeth, the spacing of which forms channels configured to implement a rectilinear flow of streams of water. In other words, the channels are formed between two separate teeth. The channels are of reduced size in order to create a pressure drop which contributes to the homogeneous distribution of the water flow along the injection channel. A channel is formed by two adjacent teeth having sides which are preferably parallel or substantially parallel to each other. The teeth obstruct the flow of water and force it to circulate within the channels, in order to initiate parallel lines of fluid in the compartments. The flow of water from the inlet and / or the recess is therefore distributed in the different channels and emerges from the latter in the form of laminar flow.Advantageously, at least a portion of the channels is configured to be oriented parallel to a flow direction of the water flow. Even more advantageously, all of the channels are oriented parallel to the flow direction of the water flow in order to enhance its homogeneity after passing through the laminar flow member. In this configuration, the laminar flow member has the shape of a comb.

[0018] According to a feature of the invention, the teeth of the laminar flow member are configured to provide resistance against a support at the laminar flow member. In addition to ensuring a laminar flow of the water, the teeth provide, perpendicular to the plane of the spacer, a mechanical resistance compatible with the stacking of several cells in series, potentially up to several tens or even several hundreds. For example, it is a tooth height which provides the required resistance. Indeed, an electrolysis cell is integrated within an electrolysis module comprising several electrolysis cells stacked on top of each other. The spacer according to the invention is therefore integrated within this stack and is therefore pressed against at least one adjacent support.The mechanical properties of the teeth, in particular their rigidity and resistance to deformation, are such that said teeth are not deformed by the support resulting from the stacking, which makes it possible to keep the channels intact and operational to make the water flow laminar when the reactor is closed and compressed to ensure the sealing of the cells. The support opposite the laminar flow member also makes it possible to participate in a delimitation of a passage section of the channels.

[0019] According to a feature of the invention, the distribution zone comprises a distribution chamber extending between any one of the inlet or outlet and the laminar flow member. The distribution chamber participates in distributing the flow of water to the entire laminar flow member, i.e. along the edge of the recess. The distribution chamber thus ensures that the flow subsequently circulates over the entire surface of the recess, and therefore that the local water flow rate is homogeneous and that the cooling of the electrode takes place uniformly over its entire surface. According to a feature of the invention, the distribution chamber comprises a plurality of deflection members.The diverting members can have various shapes, the main thing being that they obstruct the flow of water so that it disperses correctly within the entire distribution chamber, and subsequently flows through each channel of the flow member, in laminar flow and in the most uniform way possible.

[0020] According to a feature of the invention, the plurality of deflecting members is configured to provide resistance against a bearing at the distribution chamber. Just like the teeth of the laminar flow member, the deflecting members are not deformed when a bearing is created against the distribution chamber during stacking. Spaces are thus preserved within the distribution chamber so that the water can always circulate therein and be correctly distributed.

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

[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. Such a configuration allows the flow of water to travel through the recess along the smallest dimension. This allows the flow of water not to be overheated during the heat exchange with the electrode opposite the recess. According to a characteristic of the invention, the inlet and the outlet are inscribed between two straight lines passing through the lateral edges.In other words, the distribution chamber is interposed between the laminar flow member and the inlet or outlet, and this in a lateral direction defined by the lateral edges of the recess.

[0023] According to a feature 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 inlet has an offset in the longitudinal direction with respect to the center of the longitudinal edges, then the outlet also has an offset in the longitudinal direction with respect to the center of the longitudinal edges but in a direction opposite to the offset of the inlet. 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.

[0024] According to a characteristic of the invention, the distribution zone is a first distribution zone, the spacer comprising a second distribution zone at least partially symmetrical to the first distribution zone with respect to a median axis of the recess. The median axis has a direction parallel to the direction of the longitudinal edges. The spacer thus comprises two distribution zones, one between the inlet and the recess, and one between the recess and the outlet. Each of the distribution zones thus respectively comprises a first laminar flow member and a second laminar flow member extending along the longitudinal edge delimiting the distribution zone specific to it.The first distribution zone further comprises a first distribution chamber extending between the inlet and the first laminar flow member, while the second distribution zone comprises a second distribution chamber extending between the second laminar flow member and the outlet.

[0025] According to a feature of the invention, the spacer comprises a first face and a second face, the spacer comprising an inlet and an outlet configured to allow water to circulate within the water electrolysis cell, the spacer further comprising at least one distribution zone connecting any one of the inlet or the outlet to the recess, the distribution zone being formed in a thickness of the spacer by opening onto the first face while the distribution zone is formed in a thickness of the spacer by opening onto the second face. The recess inside the spacer is separated into two compartments, namely an anodic structure and a cathodic structure, the separation being ensured by a separator. The first face notably comprises the inlet, one or more distribution chambers and the outlet.The second side includes the intake, one or more distribution chambers and the exhaust.

[0026] The operation of the spacer at the second face is identical to the operation of the spacer at the first face, i.e. the implementation of means for distributing and homogenizing a flow of water ensuring the cooling of one of the electrodes. The structural characteristics of the elements of each face may however vary depending on the cooling conditions and / or the cooling objectives.

[0027] According to a characteristic of the invention, the distribution zone 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 of the first face, i.e. to homogenize the flow of water circulating within the distribution zone.

[0028] 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 described above, said spacer supporting the anode structure, the cathode structure and the separator. By being powered by an electric current, the electrolysis cell makes it possible to form dihydrogen and dioxygen from water. The spacer helps to ensure homogeneous and equitably distributed cooling over the entirety of at least one surface of at least one of the electrodes of the electrolysis cell.

[0029] 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 each other.

[0030] Other characteristics and advantages of the invention will become apparent from the following description on the one hand, and from several examples of embodiment given for informational and non-limiting purposes with reference to the attached schematic drawings on the other hand, in which:

[0031] [fig 1] is a representative diagram of an exploded view of a water electrolysis cell comprising a spacer according to the invention,

[0032] [fig 2] is a view of a first face of the spacer,

[0033] [fig 3] is a view of a second face of the spacer, opposite the first face,

[0034] [fig 4] is a sectional view of part of the spacer,

[0035] [fig 5] is a diagram of an electrolysis module.

[0036] Figure 1 represents an electrolysis cell 1, more particularly an exploded sectional view showing the stack of components inside the electrolysis cell 1.

[0037] Electrolysis cell 1 is crossed by a direct electric current allowing the water to be decomposed into oxygen and hydrogen.

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

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

[0040] The anode structure 3 comprises a bipolar plate 31 common with an upper adjacent cell, an anode grid 32 and an anode porous component 33 generally consisting of titanium particles or fibers sintered together under vacuum. The anode structure 3 may also comprise fixing means 34 adapted to the shape of the electrolysis cell 1 and which allow the fixing of the bipolar plate 31, the grid 32 and the porous component 33. These three constituent elements of the anode structure 3 make it possible to optimize the electrical conduction, the mechanical resistance and contribute to good fluid distribution.The cathode structure 4 also comprises a second bipolar plate 41 common with a lower adjacent cell, a cathode grid 42 and a cathode porous component 43 of the same nature as the anodic porous component 33 or else made of carbon, all these components having the same properties as the elements integrated into the anodic structure 3. When the electrolysis cell 1 is in operation, that is to say crossed by a direct current, the electrolysis cell 1 releases heat. The anodic structure 3 and the cathodic structure 4 heat by Joule effect as does the polymer membrane of the separator 2 due to its ionic conduction. The catalytic layers of the separator 2 also produce heat.The electrolysis cell 1 must therefore be continuously cooled so as to maintain its temperature below a maximum value, which depends on the chemical nature of the membrane of the separator 2, typically less than 100°C, in order to extend their service life and avoid 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 are inserted into a recess in the center of the spacer 5. The bipolar plates 31 and 41 cover the spacer 5 and keep the constituent elements of the anode structure 3 and the cathode structure 4 in place and in contact with each other.Thus, the porous anodic 33 and cathodic 43 components are in contact with the catalytic layers of the separator 2. The spacer 5 also participates in the circulation of water in each of the two compartments, in order to supply the reaction with water and to ensure the cooling of the electrodes as will be described in detail later. The electrolysis cell 1 can also rest on a support plate 6.

[0041] Figure 2 is a representation of the spacer 5 seen from above, that is to say seen in a direction perpendicular to the plane of the electrolysis cell 1. This representation is a view of the anode face. More precisely, Figure 2 represents a first face 51 of the spacer 5, here the anode face of the spacer.

[0042] The spacer 5 is a parallelepiped volume element with a square or rectangular base. The main plane extends in a first direction called the longitudinal direction L1 and in a second direction called the lateral direction L2. 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 frame of 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 formed by the stack of several individual electrolysis cells such as shown in FIG. 1, the stack of spacers 5 forms the injection and collection wells. The water circulating in the injection well penetrates into 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 joins the collection well forming the outlet 8. The inlet 7 and its injector and the outlet 8 and its collector respectively ensure the inlet of the water and the outlet of the two-phase mixture. The inlet 7 and the outlet 8 therefore allow water to enter and exit the electrolysis cell in order to supply and cool the latter. The spacer 5 also includes the recess 9, mentioned in figure 1, and intended to be filled in particular by the separator and by the anode and cathode structures of the electrolysis cell. Thus, when the 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, the recess 9 being in fluid communication with both the inlet 7 and the outlet 8.The spacer 5 further comprises at least one distribution zone 10 interposed between the recess 9 and any one of the inlet 7 or the outlet 8. The distribution zone 10 provides a fluid connection between the inlet 7 and the recess 9, or between the recess 9 and the outlet 8. In Figure 2, the spacer 5 comprises a first distribution zone 11 arranged between the inlet 7 and the recess 9, and a second distribution zone 12 arranged between the recess 9 and the outlet 8. The first distribution zone can be called the inlet distribution zone, while the second distribution zone can be called the outlet collection zone.

[0043] If Figures 2 and 3 mention a symmetry between the inlet and outlet of the same cell, an asymmetry of size and geometry can be envisaged. Indeed, during the reaction, there is an increase in volume by the gases produced. The section of the well can be different, as represented between Figure 2 and Figure 3. Such a difference in section is implemented in order to accommodate the difference in flow rate between the two compartments, because there is more water flow circulating in the anode circuit, in comparison with 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. Similarly, it is possible to imagine a geometric difference between the two to facilitate the evacuation of gas bubbles.In other words, the invention also relates to a spacer in which the wells and / or the distribution / distribution zones can be of different size and geometry at the inlet and outlet.

[0044] The second distribution zone 12 is at least partially symmetrical to the first distribution zone 11 with respect to a median axis 13 of the recess 9, said median axis 13 being parallel to the longitudinal direction L1. The particularity of the spacer 5 according to the invention is that the distribution zone 10, whether it is the first distribution zone 11 or the second distribution zone 12, comprises a laminar flow member 14 extending along an edge of the recess 9. In Figure 2, the first distribution zone 11 comprises a first laminar flow member 15 while the second distribution zone 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 parallelizing streams of water forming the flow of water circulating between the inlet 7 and the outlet 8.The water flow is thus less turbulent, and then circulates homogeneously, which contributes to better cooling efficiency. The recess 9 has a rectangular overall shape comprising two longitudinal edges 17 and two lateral edges 18 parallel in pairs. More precisely, 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 lateral 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 limited thermal stability and in order to ensure a homogeneous 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 entire first longitudinal edge 17a, while the second laminar flow member 16 extends along the second longitudinal edge 17b, preferably over the entire first longitudinal edge 17b. Each laminar flow member 14 comprises teeth 29 delimiting channels 19, a channel 19 being delimited by two adjacent teeth 29.It is by circulating through these channels 19 that the streams of water forming the water flow circulate in parallel to each other. Preferably, at least a portion of the channels 19 has a main direction parallel to the lateral direction L2, that is to say to the flow direction of the cooling water flow. More preferably, all of the channels 19 are parallel to the lateral direction L2. The laminar flow member 14 then has a comb shape whose geometry 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. According to one example, combs forming the laminar flow member 14, 16 may have a distinct hydraulic diameter.Each distribution zone 10 also comprises a distribution chamber 20 extending between any one of the inlet 7 to the outlet 8 to one of the laminar flow members 14. In Figure 2, the first distribution zone 11 comprises a first distribution chamber 21 arranged between the inlet 7 and the first laminar flow member 15. The second distribution zone 12 comprises a second distribution chamber 22 arranged between the second laminar flow member 16 and the outlet 8. The length of the first distribution chamber 21 and the second distribution chamber 22 can 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 illustrated in FIG. 2, the water ensuring the operation and cooling of the electrolysis cell enters the latter via the inlet 7, then passes in order through the first distribution chamber 21, the first laminar flow member 15, then passes through the recess from the first longitudinal edge 17a to the second longitudinal edge 17b. At the outlet of the recess 9, the two-phase mixture passes through the second laminar flow member 16, then the second distribution chamber 22 before leaving the electrolysis cell to reach the outlet 8. The first distribution chamber 21 and the second distribution chamber 22 are formed in a thickness of the spacer 5 by opening onto the first face 51. Each distribution 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 an equitable distribution of the flow to all of the channels 19. Preferably, the deflection members 23 have shapes promoting the homogenization and / or the guidance of the water flow, in particular the parallelization of the streams of water which pass through the electrolysis cell. Thus, near the inlet 7 or the outlet 8, the deflection members 23 have an oblong shape extending mainly in a parallel manner to the circulation of the water flow, in order to ensure at least partial homogenization at the time of entry of the water flow into the first distribution chamber 21, or before exiting from the intermediary 5. Each distribution chamber 20 may also comprise other oblong deflection members 23 extending mainly in a perpendicular manner to the circulation of the water flow.These deflection members 23 ensure distribution of the water to the portions of the first distribution chamber 21 furthest from the inlet 7. Thus, thanks to the deflection members 23 of the first distribution chamber 21 and the channels 19 of the first laminar flow member 15, the flow of water arrives in a laminar manner and equally distributed along the electrode to be cooled, guaranteeing an optimal 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 Figure 2, the inlet 7 and the outlet 8 are offset from each other in the longitudinal direction L1 and in an opposite direction with respect to each other. It is also possible to envisage arranging the inlet 7 and the outlet 8 both centered with respect to the longitudinal edges 17.The inlet 7 and the outlet 8 are however positioned so as to be between two straight lines Z1, Z2 passing through the lateral edges 18.

[0045] The spacer 5 also comprises a sealing member 24 extending around the inlet 7, the outlet 8, the distribution zones 10 and the recess 9. The sealing member 24 prevents water leaks and ensures that the water flow flows as described above. The spacer 5 further comprises an internal seal, arranged under each longitudinal edge 17 and each lateral edge 18, making it possible to prevent water infiltration between said edges and the separator.

[0046] In Figure 2, it is also possible to observe that the spacer 5 also comprises an inlet 25 and an outlet 26 which are however outside the sealing member 24 and are therefore not fluidically connected to all of the above-mentioned elements but which serve to ensure the circulation of water along a face opposite the first face 51 of the spacer 5.

[0047] Figure 3 illustrates a second face 52 of the spacer 5, corresponding to the opposite face of the first face 51 described in Figure 2. It is at the level of the second face 52 that the inlet 25 and the outlet 26 are fluidically connected. 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 side, while the second face 52 corresponds to the face on the cathode structure side.When the spacer 5 comprises two faces 51, 52 as illustrated in Figures 2 and 3, said spacer 5 then comprises at least one distribution zone 60, here a first distribution zone 61 and a second distribution zone 62, which is the equivalent of the distribution zone described in Figure 2. Each distribution zone 60 comprises a distribution chamber 63 and a laminar flow device 64 which are respectively the equivalent of the distribution chamber and the laminar flow member described in Figure 2. Just 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.The distribution chambers 63, on the other hand, comprise only oblong deflection members 23 extending mainly in the direction of circulation of the water flow and located near the inlet 25 or the outlet 26 and making it possible to homogenize the water flow at the outlet of the inlet 25 or upstream of the outlet 26. Indeed, the inlet 25 and the outlet 26 having 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 more intense pressure of the second flow of water is therefore sufficient to distribute the water at the level of all the channels 19 of the laminar flow device 64 without the need for deflection members 23 having the function of ensuring such distribution. The spacer 5 comprises a sealing device 65 having the same role as the sealing member illustrated in figure 2.Unlike the sealing member, the sealing device 65 extends in particular around the inlet 25 and the outlet 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 inlet 25 and the outlet 26 passing through the distribution zone(s) 60 and circulating along the recess 9. With the exception of the characteristics described previously and in relation to FIG. 3, reference will be made to the description of FIG. 2 concerning the structural and functional characteristics common to the two faces 51, 52 of the spacer 5.

[0048] Figure 4 shows a sectional view of the spacer, more particularly of the first face 51 and the second face 52 at the laminar flow member 14 and the laminar flow device 64. The sealing member 24 and the sealing device 65 are also partially visible. As previously described, 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 making it possible to resist a support 28 exerted on the spacer, for example a first support 28a exerted on the first face 51 and a second support 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 of each face 51, 52 of the spacer mechanically retain them. Thus, once the entire electrolysis cell is stacked, the channels 19 are closed without being obstructed, and the circulation of water can take place. Although Figure 4 illustrates supports exerted on the laminar flow member 14 and on the laminar flow device 64, similar supports are also implemented at the distribution chamber and the distribution chamber. In such a configuration, it is the deflection members which have mechanical resistance in order to maintain the circulation of water despite the pressure exerted by such supports. Figure 5 illustrates a water electrolysis module 70 consisting of a plurality of electrolysis cells 1 stacked on top of each 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 inlet pipe 71 which connects, for example, with the inlet of the spacer inside the reactor and a second inlet pipe 72 which connects with the inlet of the spacer inside the reactor. The first inlet pipe 71 and the second inlet pipe 72 provide an inlet of water into the electrolysis module 70. More precisely, the first inlet pipe 71 allows an inlet of water intended to interact with all of the anode compartments of the electrolysis module 70, for example to cool them and / or to feed the water electrolysis reaction.The second inlet pipe 72 allows an inlet of water intended to interact with all of the cathode compartments of the electrolysis module 70, for example to cool them and / or to feed the water electrolysis reaction. Each inlet pipe 71, 72 therefore comprises several outlet orifices, each allowing a circulation of water near the anode and cathode compartments depending on the inlet pipe 71, 72 considered. The electrolysis module 70 further comprises a first outlet pipe 73 which makes the junction with the outlet of the spacer inside the reactor and a second outlet pipe 74 which makes the junction with the evacuation of the spacer inside the reactor, both also extending mainly in the stacking direction E.The first outgoing pipe 73 makes it possible to collect the two-phase water-oxygen mixture produced inside the anode compartments of the reactor after circulation of the water near the anode catalytic layers of the electrolysis module 70.

[0049] The second outgoing pipe 74 makes it possible to collect the two-phase water-hydrogen mixture produced inside the cathode compartments of the reactor after circulation of the water near the cathode catalytic layers of the electrolysis module 70. In order to ensure the stacking and sealing of the electrolysis cells 1 within the electrolysis module 70, the latter also comprises a plurality of fixing means 75 making it possible to press the electrolysis cells 1 together in the stacking direction E. Of course, the invention is not limited to the examples which have just been described and numerous adjustments can be made to these examples without departing from the scope of the invention.

[0050] The invention, as just described, achieves the aim it set itself, and makes it possible to propose an intermediary for an electrolysis cell ensuring homogeneous fluid distribution over the entirety of said electrolysis cell. Variants not described here could be implemented without departing from the context of the invention, provided that, in accordance with the invention, they comprise an intermediary in accordance with the invention.

Claims

CLAIMS 1- Spacer (5) of a water electrolysis cell (1) configured to support a separator (2), comprising at least one inlet (7) and one outlet (8) configured to allow circulation of water within the water electrolysis cell (1), the spacer (5) comprising a recess (9) intended to be occupied by the separator (2) and in fluid communication with the inlet (7) and the outlet (8), the spacer (5) further comprising at least one distribution zone (10) connecting any one of the inlet (7) or the outlet (8) to the recess (9), characterized in that the distribution zone (10) comprises at least one laminar flow member (14) extending along an edge (17, 18) of the recess (9). 2- Spacer (5) according to claim 1, in which the laminar flow member (14) comprises a plurality of teeth (29) whose spacing forms channels (19) configured to implement a rectilinear flow of water streams. 3- Spacer (5) according to the preceding claim, in which the teeth (29) of the laminar flow member (14) are configured to provide resistance against a support (28) at the level of the laminar flow member (14). 4- Spacer (5) according to any one of the preceding claims, in which the distribution zone (10) comprises a distribution chamber (20) extending between either the inlet (7) or the outlet (8) and the laminar flow member (14). 5- Spacer (5) according to the preceding claim, in which the distribution chamber (20) comprises a plurality of deflection members (23). 6- Spacer (5) according to the preceding claim, in which the plurality of deflection members (23) is configured to provide resistance against a support (28) at the distribution chamber (20). 7- Spacer (5) according to claim 5 or 6, in which at least one deflection member (23) is oblong. 8- Spacer (5) according to any one of the preceding claims, in which the recess (9) is rectangular in shape and has two longitudinal edges (17) and two side edges (18), the laminar flow member (14) being arranged along one of the longitudinal edges (17). 9- Spacer (5) according to the preceding claim, in which the inlet (7) and the outlet (8) are inscribed between two straight lines (Zl, Z2) passing through the lateral edges (18). 10- Spacer (5) according to any one of the preceding claims, in which the inlet (7) and the outlet (8) are arranged symmetrically with respect to a central point (Y) of said spacer (5). 11- Spacer (5) according to any one of the preceding claims, in which the distribution zone (10) is a first distribution zone (11), the spacer (5) comprising a second distribution zone (12) at least partially symmetrical to the first distribution zone (11) relative to a median axis (13) of the recess (9). 12- Spacer (5) according to any one of the preceding claims, comprising a first face (51) and a second face (52), the spacer (5) comprising an inlet (25) and an outlet (26) configured to allow circulation of water within the water electrolysis cell (1), the spacer (5) further comprising at least one distribution zone (60) connecting any one of the inlet (25) or the outlet (26) to the recess (9), the distribution zone (10) being formed in a thickness of the spacer (5) by opening onto the first face (51) while the distribution zone (60) being formed in a thickness of the spacer (5) by opening onto the second face (52). 13- Spacer (5) according to the preceding claim, in which the distribution zone (60) comprises at least one laminar flow device (64) extending along an edge (17, 18) of the recess (9). 14- Water electrolysis cell (1) comprising an anode (3), a cathode (4) and a separator (2) interposed between the anode (3) and the cathode (4), the water electrolysis cell (1) comprising a spacer (5) according to any one of the preceding claims, said spacer (5) supporting the anode (3), the cathode (4) and the separator 15- Water electrolysis module (70) comprising a plurality of electrolysis cells (1) according to the preceding claim, the electrolysis cells (1) being stacked on top of each other.

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