Spacer for water electrolysis cell

Abstract

Spacer for water electrolysis cell The present invention relates to a spacer(5) of a water electrolysis cell configured to support a separator, comprising at least one inlet (7) and one outlet (8) configured to allow water circulation within the water electrolysis cell, the spacer (5) comprising a recess (9) intended to be occupied by the separator and in fluidic 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 outlet (8) to the recess (9), characterized in that the distribution zone (10) comprises at least one laminar flow element (14) extending along an edge (17, 18) of the recess (9). The invention also relates to an electrolysis cell comprising such a spacer (5). (Figure 2)

Description

Title of the invention: Spacer for a water electrolysis cell

[0001] Generally speaking, electrolysis is a technique for carrying out non-spontaneous chemical reactions using a direct electric current flowing between two electrodes placed opposite each other, called the anode and cathode, and separated by an ionically conductive medium called the electrolyte. The electrodes, which can be solid or porous, can be of various types (e.g., plates, sheets, grids). Each of the two half-reactions requires the use of an electrocatalyst to maximize its kinetics. The electrocatalysts, generally made of expensive materials, are deposited on the surface of the anode and 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 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 one on top of the 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 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 type of separator used depends on the electrolysis technology. For example, some electrolysis technologies use a polymer membrane with cationic conduction (proton conduction) or anionic conduction (hydroxyl ion conduction) as a separator. Other technologies use porous thermoplastic or ceramic separators.

[0003] Let us consider, as a specific example, the case of liquid water electrolysis using the so-called acid polymer electrolyte technology (known by the English 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 within it. 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 CCMs. (acronym for catalyst-coated membrane). A water electrolysis reactor, for example, a proton exchange membrane reactor, comprises two liquid water injection wells and two collection wells for two-phase mixtures. Each compartment of each cell has a water inlet (liquid or vapor, depending on the technology) supplied by the injection well and a reaction mixture outlet (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 anodic circuit and a cathodic circuit. The anodic injection and collection wells are fluidically connected to the anodic circuit. The cathodic injection and collection wells are fluidly connected to the cathodic circuit.Liquid water circulates in each of these two circuits using a pump, following an internal vortex flow from the injection well to the collection well. Each circuit comprises various functional units, such as a liquid-gas separator that separates and collects the reaction gases, a heat exchanger that extracts the heat produced in the electrolysis cells, a resin bed that controls the conductivity of the circulating water, a pump that ensures water circulation within the circuit, and various pressure, temperature, and flow sensors that allow the system to be controlled by a programmable logic controller (PLC). More complex configurations exist where several reactors are electrically and fluidically interconnected, either in series or parallel, each with its own individual or shared anode and cathode circuit.During operation, liquid water is pumped into each compartment of each cell, and a biphasic mixture (liquid water and the gas generated within 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 anodic structure, and a mixture of liquid water and hydrogen gas is collected at the outlet of the cathodic structure. The flow of liquid water through the anodic structure of each cell serves both to power the electrolysis reaction and to cool the anodic structure, as the oxygen release reaction is exothermic. The flow of liquid water through the cathodic structure of each cell serves both to collect the electro-osmotic water flow across the membrane and to cool the cathode, as the hydrogen release reaction is exothermic.

[0004] The invention primarily covers a spacer for a water electrolysis cell configured to support a separator, comprising at least one inlet and one outlet configured to allow water circulation within the water electrolysis cell, the spacer comprising a recess intended to be occupied by the separator and in fluidic communication with the inlet and outlet, the spacer further comprising at least one distribution zone connecting any of the inlet or outlet to the recess, innovative in that the distribution zone includes at least one laminar flow element extending along an edge of the recess.

[0005] The present invention relates essentially to a frame preferably made of low-thickness, for example a few millimeters, preferably made of injectable thermoplastic material, hollow in the middle, preferably square or rectangular in shape, pierced with preferably circular holes 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 to ensure fluidic sealing between the inside of the reactor and the outside, 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 challenge for those skilled in the art lies in ensuring a homogeneous and constant water flow at every point in each compartment of each cell of the water electrolysis reactor, so as to properly supply and cool each electrode in each compartment of each cell. When no particular precautions are taken to control the fluid distribution within the cell compartments, the water distribution both inside each cell and from one cell to another is not optimal; that is to say, the water flow through each compartment of each cell is heterogeneous and varies from one point to another.For example, in the case of a rectangular spacer with an inlet point at one of its four corners and a diagonally opposite outlet point, the water flow will tend to follow 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 across the active electrochemical surface, resulting in inconsistent operation, reduced energy efficiency, and accelerated reactor aging. Furthermore, the water flow along the shortest path is rapid, which tends to create hydraulic turbulence, further disrupting operation.

[0006] The present invention describes a spacer that addresses these problems, and in particular ensures homogeneous water circulation at every point in each compartment of each cell of a water electrolysis module. The homogeneity of the water circulation also indirectly ensures the proper functioning of the electrolysis cells as a whole, by controlling the injection pressure losses. Such a water electrolysis cell spacer is further designed to accommodate a separator, for example, a polymer electrolysis membrane.

[0007] The spacer can be made of different materials, for example thermoplastic materials for so-called "low temperature" applications, such as a proton exchange membrane cell or an anion exchange membrane cell or an alkaline electrolysis cell.

[0008] 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.

[0009] Advantageously, the inlet may include a fluidic injector and an injection well, and the outlet may include a collection well and a fluidic manifold. The spacer is hollowed out in its center and has a peripheral support equipped with a sealing gasket onto which the separator is pressed so as to separate the cell into two distinct compartments, anodic and cathodic. The hollowed-out spacer is in fluidic communication with the anodic and cathodic circuits. The fluidic injector connects the injection well to the fluidic distribution zone at the inlet, optionally one per compartment, and at least one fluidic manifold connects the fluidic distribution zone to the collection well at the outlet.The spacer is characterized in that the fluidic distribution zone includes at least one laminar flow element extending along an edge of the recess, i.e. along one of the inner sides of the spacer in fluidic contact with the central recess.

[0010] The laminar flow element generates a plurality of straight streams of water.

[0011] Furthermore, the space of each compartment located between the flow elements The inlet and outlet laminar system 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.

[0012] Thanks to this set of fluidic and mechanical characteristics, the spacer of the invention allows the water flows circulating in the two compartments of each elementary cell to flow homogeneously along the active surface of each compartment, thus ensuring homogeneous operation and extending the lifespan of the electrolysis cell while maximizing the reactor's energy efficiency. The spacer of the invention also ensures the same level of fluidic homogeneity in each compartment of each cell of an electrochemical reactor, regardless of their number. The spacer's characteristics are independent of its size. Indeed, the spacer has fluidic, mechanical, and dimensional characteristics adapted to the size of the electrolysis cell.

[0013] The recess at the inlet of each cell compartment is positioned opposite the active surface of the cell. After entering the cell compartment, the laminar water flow runs along this recess, thus providing homogeneous cooling of the active surface of the cell, for example, the surface of one of the electrodes. This cooling occurs through heat exchange, and the water temperature therefore increases as it flows along the recess. The heated water then exits the cell via the outlet located opposite the inlet.

[0014] The fluid distribution zone is arranged between the inlet and the recess and / or between the recess and the outlet. It is within this distribution zone that the water flow is homogenized, notably by means of the laminar flow element. This element is positioned as close as possible to the recess. For example, when the distribution zone is arranged between the inlet and the recess, the laminar flow element is positioned along the edge of the recess corresponding to the edge through which the water enters the recess. This ensures a laminar water flow formed directly upon entry into the recess.

[0015] According to one feature of the invention, the laminar flow element comprises a plurality of teeth, the spacing of which forms channels configured to implement a rectilinear flow of water streams. In other words, the channels are formed between two disjointed teeth. The channels are of small size in order to create a pressure drop that contributes to the homogeneous distribution of the water flow along the injection channel. A channel is formed by two adjacent teeth having sides that are preferably parallel or substantially parallel to each other. The teeth impede the water flow and force it to circulate within the channels, in order to initiate parallel fluid lines in the compartments. The water flow from the inlet and / or the outlet is thus distributed in the different channels and exits them as laminar flow.Advantageously, at least some of the channels are configured to be oriented parallel to the direction of water flow. Even more advantageously, all the channels are oriented parallel to the direction of water flow to enhance its homogeneity after passing through the laminar flow element. In this configuration, the laminar flow element has a comb-like shape.

[0016] According to one feature of the invention, the teeth of the laminar flow element are configured to provide resistance against support at the level of the laminar flow element. In addition to ensuring laminar water flow, the teeth, perpendicular to the plane of the spacer, provide mechanical resistance compatible with the stacking of several cells in series, potentially This can be achieved up to several dozen or even several hundred times. For example, it is the height of the teeth that provides the required resistance. Indeed, an electrolysis cell is integrated within an electrolysis module comprising several electrolysis cells stacked one on top of the other. The spacer according to the invention is therefore integrated within this stack and is thus 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 ensure laminar water flow when the reactor is closed and compressed to ensure the cells are sealed. The support opposite the laminar flow element also helps to define a cross-section for the passage of the channels.

[0017] According to one feature of the invention, the distribution zone comprises a distribution chamber extending between any one of the inlet or outlet and the laminar flow element. The distribution chamber helps to distribute the water flow to the entire laminar flow element, that is, 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 is homogeneous and that the electrode is cooled uniformly over its entire surface.

[0018] According to one feature of the invention, the distribution chamber comprises a plurality of deflection elements. The deflection elements may have various shapes, the essential point being that they obstruct the flow of water so that it disperses correctly throughout the entire distribution chamber, and subsequently flows through each channel of the flow element, in laminar flow and in the most uniform manner possible.

[0019] According to one feature of the invention, the plurality of deflection elements is configured to provide resistance against pressure exerted on the distribution chamber. Like the teeth of the laminar flow element, the deflection elements are not deformed when pressure is exerted against the distribution chamber during stacking. Spaces are thus maintained within the distribution chamber so that water can always flow through it and be properly distributed.

[0020] According to one feature of the invention, at least one deflection element is oblong. An oblong deflection element guides the water flow more precisely along a preferred direction. Oblong deflection elements may, for example, have a principal direction parallel to the water flow to promote its laminar flow. Oblong deflection elements may also have a principal direction perpendicular to the water flow in order to circulate, at least partially, the water towards the portions of the distribution chamber furthest from the inlet or recess, thus promoting the homogeneity of the water flow.

[0021] According to one feature of the invention, the recess is rectangular in shape and has two longitudinal edges and two lateral edges, the laminar flow element being arranged along one of the longitudinal edges. The longitudinal edges are parallel in pairs, as are the lateral edges. The laminar flow element is arranged so that the water flow passes through the recess from one longitudinal edge to the other. This configuration allows the water flow to travel through the recess along its smallest dimension. This prevents the water flow from being excessively heated during heat exchange with the electrode opposite the recess.

[0022] According to one feature of the invention, the inlet and outlet lie between two straight lines passing through the lateral edges. In other words, the distribution chamber is interposed between the laminar flow element and the inlet or outlet, in a lateral direction defined by the lateral edges of the recess.

[0023] According to one feature of the invention, the inlet and outlet are arranged symmetrically with respect to a central point of said spacer. By way of 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 is offset along the longitudinal direction with respect to the center of the longitudinal edges, then the outlet is also offset along the longitudinal direction with respect to the center of the longitudinal edges, but in the opposite direction 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 one feature 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 comprises, respectively, a first laminar flow element and a second laminar flow element extending along the longitudinal edge delimiting its own distribution zone.The first distribution zone also includes a first distribution chamber extending between the inlet and the first laminar flow element, while the second distribution zone includes a second distribution chamber extending between the second laminar flow element and the outlet.

[0025] According to one 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 circulation within the water electrolysis cell, the spacer further comprising at least one distribution zone connecting any one of the inlet or outlet to the recess, the distribution zone being formed in a thickness of the spacer opening onto the first face, while the distribution zone is formed in a thickness of the spacer 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 includes, in particular, the inlet, one or more distribution chambers, and the outlet.The second side, meanwhile, includes the intake, one or more distribution chambers, and the evacuation.

[0026] The operation of the spacer on the second face is identical to the operation of the spacer on the first face, namely the implementation of means to distribute and homogenize a water flow ensuring the cooling of one of the electrodes. However, the structural characteristics of the elements on each face may vary depending on the cooling conditions and / or the cooling objectives.

[0027] According to one feature 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 element of the first face, namely to homogenize the flow of water circulating within the distribution zone.

[0028] The invention also covers a water electrolysis cell comprising an anodic structure, a cathodic structure, and a separator interposed between the anodic and cathodic structures. The water electrolysis cell includes a spacer as described above, said spacer supporting the anodic structure, the cathodic structure, and the separator. When supplied with an electric current, the electrolysis cell produces dihydrogen and dioxygen from water. The spacer helps to ensure homogeneous and evenly distributed cooling over 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 one on top of the other.

[0030] Other features and advantages of the invention will become apparent from the following description on the one hand, and from several embodiments given as examples. indicative and not exhaustive, with reference to the attached schematic drawings, on 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 cross-sectional view of part of the spacer,

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

[0036] Fig. 1 represents an electrolysis cell 1, more particularly an exploded cross-sectional view showing the stacking of components inside the electrolysis cell 1. The electrolysis cell 1 is traversed by a direct electric current enabling the decomposition of water into dioxygen and dihydrogen.

[0037] 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 electrical generator, not shown. By way of example, the separator 2 may be a membrane-electrocatalyst 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.

[0038] In general, the invention can also be applied to other types of cells, such as solid oxide electrolysis cells.

[0039] The anodic structure 3 comprises a bipolar plate 31 common to an adjacent upper cell, an anodic grid 32, and a porous anodic component 33 generally made of titanium particles or fibers sintered together under vacuum. The anodic structure 3 may also include fastening means 34 adapted to the shape of the electrolysis cell 1 and enabling the attachment of the bipolar plate 31, the grid 32, and the porous component 33. These three constituent elements of the anodic structure 3 optimize electrical conductivity and mechanical strength and contribute to good fluid distribution.The cathode structure 4 also includes a second bipolar plate 41 common with an adjacent lower cell, a cathode grid 42, and a porous cathode component 43 of the same material as the porous anodic component 33, or alternatively, 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, i.e., when a direct current flows through it, the electrolysis cell 1 releases heat. The anodic structure 3 and the cathodic structure 4 heat up by Joule heating. The polymer membrane of separator 2 is subject to ionic conduction. The catalytic layers of separator 2 also generate heat. Therefore, the electrolysis cell 1 must be continuously cooled to maintain its temperature below a maximum value, which depends on the chemical composition of the membrane of separator 2, typically below 100°C, in order to extend its lifespan and prevent premature damage. To achieve this, a water circuit (not shown) circulates water through at least the anodic or cathodic structure to cool it / them. The electrolysis cell 1 also includes a spacer 5 supporting the separator 2 in its center. The anodic structure 3 and the cathodic structure 4 fit into a recess in the center of the spacer 5.The bipolar plates 31 and 41 are positioned over the spacer 5 and hold the constituent elements of the anodic structure 3 and the cathodic structure 4 in place and in contact with each other. Thus, the porous anodic component 33 and cathodic component 43 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 can also rest on a support plate 6.

[0040] Figure 2 is a representation of the spacer 5 viewed from above, that is, viewed along a direction perpendicular to the plane of the electrolysis cell 1. This representation is a view of the anodic face. More precisely, Figure 2 represents a first face 51 of the spacer 5, here the anodic face of the spacer.

[0041] The spacer 5 is a parallelepiped-shaped volumetric element with a square or rectangular base. The main plane extends along a first direction called the longitudinal direction L1 and along a second direction called the lateral direction L2. The thickness of the frame extends along a direction perpendicular to the main plane. The spacer 5 includes two through-holes, a fluid inlet 7 and a fluid outlet 8. Preferably, within the frame of the electrolysis cell 1, the inlet 7 includes a fluid injector and an injection well, and the outlet 8 includes 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 enters the structure of spacer 5.The two-phase mixture, that is, a mixture of water and oxygen or hydrogen, then leaves the spacer compartment 5 and enters the collection well forming outlet 8. Inlet 7 and its injector, and outlet 8 and its manifold, respectively, provide the water inlet and the two-phase mixture outlet. Inlet 7 and outlet 8 thus allow... Water enters and exits the electrolysis cell to supply and cool it. The spacer 5 also includes the recess 9, mentioned in [Fig. 1], which is intended to be filled in particular by the separator and by the anodic and cathodic 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, the recess 9 being in fluidic communication with both the inlet 7 and the outlet 8. The spacer 5 also includes at least one distribution zone 10 interposed between the recess 9 and any one of the inlet 7 or outlet 8. The distribution zone 10 ensures a fluidic connection between the inlet 7 and the recess 9, or between the recess 9 and the outlet 8. On the [Fig.[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.

[0042] While Figures 2 and 3 show symmetry between the inlet and outlet of the same cell, asymmetry in size and geometry is possible. Indeed, during the reaction, there is an increase in volume due to the gases produced. The well cross-section can be different, as shown in [Fig. 2] and [Fig. 3]. Such a difference in cross-section is implemented to accommodate the difference in flow rate between the two compartments, since there is a higher flow rate of water circulating in the anodic circuit compared to the cathodic circuit. It is therefore possible to adapt the diameter of the wells within the same compartment to accommodate the increase in volumetric flow rate induced by the formation of gas during the reaction. Similarly, a geometric difference between the two can be envisioned to facilitate the evacuation of gas bubbles.In other words, the invention also relates to a spacer in which the wells and / or distribution / re-distribution zones can be of different sizes and geometries at the inlet and outlet.

[0043] 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 LL. The distinctive feature of the spacer 5 according to the invention is that the distribution zone 10, whether it be the first distribution zone 11 or the second distribution zone 12, comprises a laminar flow element 14 extending along an edge of the recess 9. In [Fig. 2], the first distribution zone 11 comprises a first laminar flow element 15, while the second distribution zone 12 comprises a second laminar flow element 16. The role of the laminar flow elements 14 is to homogenize the flow of water circulating within the cell electrolysis is achieved by parallelizing streams of water that form the water flow circulating between inlet 7 and outlet 8. This results in a less turbulent and more homogeneous water flow, contributing to improved cooling efficiency. The recess 9 has an overall rectangular shape comprising two longitudinal edges 17 and two lateral edges 18, parallel in pairs. More precisely, the recess 9 includes a first longitudinal edge 17a corresponding to the longitudinal edge 17 closest to inlet 7, and a second longitudinal edge 17b corresponding to the longitudinal edge 17 closest to outlet 8. The lateral edges 18 are perpendicular to the longitudinal edges 17.The spacer 5 is arranged so that the water flows parallel to the lateral direction L2, thus minimizing the distance it travels along the electrolysis cell. The aim is to prevent the water from reaching an excessively high outlet temperature, thereby protecting the separator, which has limited thermal stability, and ensuring a homogeneous flow of current along a direction parallel to the thickness of the spacer 5, through the electrolysis cell. Thus, the first laminar flow element 15 extends along the first longitudinal edge 17a, preferably along its entire length, while the second laminar flow element 16 extends along the second longitudinal edge 17b, preferably along its entire length. Each laminar flow organ 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 water streams forming the water flow circulate parallel to each other. Preferably, at least some of the channels 19 have a principal direction parallel to the lateral direction L2, that is, to the flow direction of the cooling water. Even more preferably, all the channels 19 are parallel to the lateral direction L2. The laminar flow element 14 then has a comb-like shape whose geometry is optimized according to the hydraulic flow through the electrolysis cell so as to satisfy the constraint imposed on the maximum outlet temperature. As an example, the combs forming the laminar flow element 14, 16 may have distinct hydraulic diameters.Each distribution zone 10 also includes a distribution chamber 20 extending from any one of the inlet 7 to the outlet 8 to one of the laminar flow elements 14. In [Fig. 2], the first distribution zone 11 includes a first distribution chamber 21 located between the inlet 7 and the first laminar flow element 15. The second distribution zone 12 includes a second distribution chamber 22 located between the second laminar flow element 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 through them. The cell is designed to meet the imposed maximum outlet temperature constraint. Thus, according to the configuration of the spacer 5 illustrated in [Fig. 2], the water that powers and cools the electrolysis cell enters it via inlet 7, then flows successively through the first distribution chamber 21, the first laminar flow element 15, and then 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 flows through the second laminar flow element 16, then the second distribution chamber 22 before exiting the electrolysis cell to reach the outlet 8. The first distribution chamber 21 and the second distribution chamber 22 are formed within the thickness of the spacer 5, opening onto the first face 51.Each distribution chamber 20 may include a plurality of diverters 23 configured to obstruct the flow of water circulating from the inlet 7 to the outlet 8. The diverters 23 ensure an even distribution of the flow to all the channels 19. Preferably, the diverters 23 have shapes that promote the homogenization and / or guidance of the water flow, in particular the parallelization of the water streams passing through the electrolysis cell. Thus, near the inlet 7 or the outlet 8, the diverters 23 have an oblong shape extending primarily parallel to the direction of the water flow, in order to ensure at least partial homogenization upon the entry of the water flow into the first distribution chamber 21, or before exiting the spacer 5.Each distribution chamber 20 may also include additional oblong diverters 23 extending primarily perpendicularly to the water flow. These diverters 23 ensure water distribution to the portions of the first distribution chamber 21 furthest from the inlet 7. Thus, thanks to the diverters 23 of the first distribution chamber 21 and the channels 19 of the first laminar flow element 15, the water flow reaches the electrode to be cooled in a laminar and evenly distributed manner, guaranteeing 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 [Fig.2], the inlet 7 and the outlet 8 are offset from each other along the longitudinal direction L1 and in opposite directions with respect to each other.It is also possible to consider 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 fall between two lines Z1, Z2 passing through the lateral edges 18.

[0044] The spacer 5 also includes a sealing element 24 extending around the inlet 7, the outlet 8, the distribution areas 10 and the recess 9. The element The sealing element 24 prevents water leaks and ensures that the water flows as described previously. The spacer 5 also includes an internal seal, located under each longitudinal edge 17 and each lateral edge 18, preventing water infiltration between said edges and the separator.

[0045] On [Fig.2], it is also possible to observe that the spacer 5 also includes an inlet 25 and an outlet 26 which are however outside the sealing element 24 and are therefore not fluidly connected to all the aforementioned elements but which serve to ensure the circulation of water along a face opposite to the first face 51 of the spacer 5.

[0046] 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. The inlet 25 and outlet 26 are fluidly connected at this second face 52. It is thus understood that a first water flow circulating along the first face 51 cools one of the compartments of the electrolysis cell, while a second water flow circulating along the second face 52 cools the other compartment of the electrolysis cell. For example, the first face 51 corresponds to the face facing the anodic structure, while the second face 52 corresponds to the face facing the cathodic structure.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 equivalent to the distribution zone described in [Fig. 2]. Each distribution zone 60 comprises a distribution chamber 63 and a laminar flow device 64, which are respectively equivalent to the distribution chamber and the laminar flow element described in [Fig. 2]. Like the laminar flow element, 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 that implement a straight flow of water streams, in order to homogenize the water flow.The distribution chambers 63, on the other hand, comprise only oblong diverter devices 23 extending mainly along the direction of water flow and located near the inlet 25 or the outlet 26, allowing for the homogenization of the water flow at the outlet of the inlet 25 or upstream of the outlet 26. Indeed, since the inlet 25 and the outlet 26 have a smaller opening than the inlet 7 and the outlet 8, the second water flow circulating along the second face 52 is at a higher pressure than the first water flow circulating along the first face. The higher pressure of the second water flow is therefore sufficient to distribute the water throughout all the channels 19 of the laminar flow device 64 without the need for diverter devices 23 whose function is to ensure such distribution. The spacer 5 includes a sealing device 65 having the same role as the sealing element illustrated in [Fig. 2]. Unlike the sealing element, the sealing device 65 extends specifically around the inlet 25 and the outlet 26 and excludes the inlet 7 and the outlet 8 so that the water flow circulating along the second face 52 circulates between the inlet 25 and the outlet 26, passing through the distribution zone(s) 60 and flowing along the recess 9. With the exception of the features described previously and in relation to [Fig. 3], reference will be made to the description in [Fig. 2] concerning the structural and functional characteristics common to the two faces 51, 52 of the spacer 5.

[0047] Fig. 4 represents a cross-sectional view of the spacer, more particularly of the first face 51 and the second face 52 at the level of 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 element 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 enabling 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 consists of a plurality of elements stacked and pressed against each other.The supports 28 are thus pressed against the spacer, and the teeth 29 on 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 water circulation can occur. Although [Fig. 4] illustrates supports exerted on the laminar flow element 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 elements that provide mechanical resistance in order to maintain water circulation despite the pressure exerted by such supports.

[0048] Figure 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 principal plane mentioned above. The electrolysis module 70 thus comprises as many electrolysis membranes, anodic compartments, and cathodic compartments as there are electrolysis cells 1. The electrolysis module 70 includes a first inlet 71 which connects, for example, with the inlet of the spacer inside the reactor and a second inlet 72 which connects with the inlet of the spacer inside the reactor. The first inlet 71 and the second Inlet pipes 72 provide water inlet to the electrolysis module 70. More specifically, the first inlet pipe 71 allows water to inlet for interaction with all the anodic compartments of the electrolysis module 70, for example, to cool them and / or to supply the water electrolysis reaction. The second inlet pipe 72 allows water to inlet for interaction with all the cathodic compartments of the electrolysis module 70, for example, to cool them and / or to supply the water electrolysis reaction. Each inlet pipe 71, 72 therefore includes several outlet ports, each allowing water to circulate near the anodic and cathodic compartments depending on the inlet pipe 71, 72 in question.The electrolysis module 70 also includes a first outlet 73 which connects with the outlet of the spacer inside the reactor and a second outlet 74 which connects with the outlet of the spacer inside the reactor, both extending mainly along the stacking direction E. The first outlet 73 allows the two-phase water-oxygen mixture produced inside the anodic compartments of the reactor to be collected after the water has circulated near the anodic catalytic layers of the electrolysis module 70.

[0049] The second outlet 74 allows the two-phase water-hydrogen mixture produced inside the cathodic compartments of the reactor to be collected after the water has circulated near the cathodic catalytic layers of the electrolysis module 70.

[0050] In order to ensure the stacking and sealing of the electrolysis cells 1 within the electrolysis module 70, the latter also includes a plurality of fixing means 75 allowing the electrolysis cells 1 to be pressed together according to the stacking direction E.

[0051] Of course, the invention is not limited to the examples just described and many modifications can be made to these examples without departing from the scope of the invention.

[0052] The invention, as described above, achieves its intended purpose and provides a spacer for an electrolysis cell that ensures homogeneous fluid distribution throughout the entire electrolysis cell. Variations not described here could be implemented without departing from the scope of the invention, provided that, in accordance with the invention, they include a spacer conforming to the invention.

Claims

Demands

1. A 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 permit water circulation within the water electrolysis cell (1), the spacer (5) comprising a recess (9) intended to be occupied by the separator (2) and in fluidic 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 outlet (8) to the recess (9), characterized in that the distribution zone (10) comprises at least one laminar flow element (14) extending along an edge (17, 18) of the recess (9).

2. Spacer (5) according to claim 1, wherein the laminar flow member (14) comprises a plurality of teeth (29) whose spacing forms channels (19) configured to implement a straight flow of water streams.

3. Spacer (5) according to the preceding claim, wherein 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, wherein the distribution zone (10) comprises a distribution chamber (20) extending between any one of the inlet (7) or outlet (8) and the laminar flow member (14).

5. Spacer (5) according to the preceding claim, wherein the distribution chamber (20) comprises a plurality of deflection members (23).

6. Spacer (5) according to the preceding claim, wherein the plurality of deflection members (23) is configured to provide resistance against a support (28) at the level of the distribution chamber (20).

7. Spacer (5) according to claim 5 or 6, wherein at least one deflection member (23) is oblong.

8. Spacer (5) according to any one of the preceding claims, wherein the recess (9) is rectangular in shape and has two longitudinal edges (17) and two lateral edges (18), the laminar flow element (14) being disposed along one of the edges. gitudinaux (17).

9. Spacer (5) according to the preceding claim, wherein the inlet (7) and the outlet (8) are inscribed between two straight lines (Z1, Z2) passing through the lateral edges (18).

10. Spacer (5) according to any one of the preceding claims, wherein the inlet (7) and 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, wherein the distribution zone (10) is a first distribution zone (11), the spacer (5) comprising a second distribution zone (12) at least partially symmetric to the first distribution zone (11) with respect 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 permit water circulation 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 outlet (26) to the recess (9), the distribution zone (10) being formed in a thickness of the spacer (5) opening onto the first face (51) while the distribution zone (60) being formed in a thickness of the spacer (5) opening onto the second face (52).

13. Spacer (5) according to the preceding claim, wherein 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 (2).

15. Water electrolysis module (70) comprising a plurality of electrolysis cells (1) according to the preceding claim, the electrolysis cells (1) being stacked one on top of the other.

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