Anion-conducting membrane, method for manufacturing such a membrane, electrochemical cell comprising such a membrane and facility comprising such a cell

Abstract

The invention relates to a layer of catalytic material for an anion-conducting membrane (10) for an electrochemical device; the layer of catalytic material comprises metal nanoparticles bound by a polymer binder. In one embodiment, the metal nanoparticles comprise a mixture of nickel nanoparticles and cobalt nanoparticles. The invention also relates to a membrane comprising a layer of catalytic material and to a method for preparing and depositing a catalytic layer.

Description

Description Title of the invention: Anionic conductive membrane, method of manufacturing such a membrane, electrochemical cell comprising such a membrane and installation comprising such a cell Technical field of the invention [1] The technical field of the invention relates to anionic conductive membranes such as those used in particular in water electrolysis devices. More particularly, the invention relates to a membrane for the alkaline electrolysis of water and a method for manufacturing such membranes. State of the art [2] Hydrogen is used in several industrial processes, including as a raw material in the chemical industry and as a reducing agent in the metallurgical industry. Hydrogen is a fundamental element for the manufacture of ammonia, and therefore fertilizers, and for the manufacture of methanol, used in the manufacture of many polymers. Another area of use is refineries, where hydrogen is used for the processing of intermediate petroleum products. [3] Hydrogen is also an important energy carrier: it can store and provide energy in a usable form. The energy is released by an exothermic combustion reaction with oxygen, thus forming water. During such a combustion reaction, no carbon-containing greenhouse gases are emitted. [4] As electricity production from renewable energy increases, so does the need for energy storage and transmission. Many renewable energy sources, particularly solar and wind, are located far from population centers and only produce electricity intermittently. Hydrogen may be the perfect carrier for renewable energy. It can store energy and then distribute it where and when it is needed. [5] Alkaline water electrolysis is an important process for producing hydrogen. In an alkaline water electrolysis cell, a membrane is used between two electrodes, a cathode and an anode: the membrane separates the electronically conductive electrodes. Non-porous to gases, the membrane also separates the gases produced at the electrodes to prevent an explosive mixture of hydrogen gas H2 (formed at the cathode) and oxygen gas O2 (formed at the anode). The membrane is also ionically conductive for the transport of OH- ions from the cathode to the anode. [6] It is known to produce proton exchange membranes (or PEM for proton-exchange membrane). The most widely used membrane is the so-called Nation® membrane marketed by the company Dupont de Nemours. The price of this membrane is particularly high. In addition, this membrane generates a very acidic environment, particularly aggressive towards the electrodes. [7] New membranes are being developed, called anion exchange membranes (or AEM membrane for anion-exchange membrane or anion-conducting membrane or anionic conducting membrane). Examples include anionic membranes such as Piperion®, Sustainion® and the Zirfon® separator. For example, Zirfon®, which is not a conductive membrane but a porous separator, comprises zirconium oxide particles bound by a polymer. Other examples include membranes comprising ceramic particles, such as the Boron Carbide membranes described in document D1 = FR3122778 or the Yttria Zirconia membranes described in document D2 = FR3150048. Made with a polymer and metal oxide and / or ceramic particles, these membranes are fairly simple to manufacture and less expensive.Also, these membranes are used in a non-acidic but basic environment, which allows the use of common metals for the electrodes, for example nickel for the cathode and stainless steel for the anode. However, all these membranes and separators are generally less efficient than membranes with catalysts, which affects the profitability of large-scale hydrogen production. [8] To improve the efficiency of membranes, it is known to deposit on the membrane a layer of catalytic materials based on rare materials, for example metals from the Platinum group, also called PGM metals (in English, for platinum group metals), a group which includes iridium (Ir), Osmium (Om), platinum (Pt), palladium (Pd), rhodium (Rh) and ruthenium (Ru). The efficiency of the AEM membrane is improved but it is observed in practice that the resistance of the catalytic layers on the membrane is limited in time and depends more strongly on the formulation of the catalytic layers and the process of deposition of these layers, anode side and cathode side. In addition, PGM metals are rare metals, which significantly increase the cost of membranes and therefore reduce the profitability of large-scale hydrogen production. Statement of the invention [9] The invention provides new catalytic layers and a new membrane which do not have all or part of the drawbacks mentioned above.

[0010] To this end, the invention proposes a new layer of catalytic material for an anionic conductive membrane for an electrochemical device, layer of catalytic material comprising nanoparticles of active components bound by a polymer binder, the active components being Nickel and Cobalt.

[0011] Advantageously, such a catalytic layer is deposited on an anionic conductive membrane on the cathode side.

[0012] The catalytic layer according to the invention, deposited on the surface of a membrane, significantly improves the efficiency of the electrochemical reactions which take place at the interfaces of the membrane and the electrodes, and the results obtained are generally more interesting than a catalytic deposit on one or other of the electrodes of a cell using a AEM membrane without catalytic deposit. Also, the yields obtained do not degrade much less over time. Finally, the metals used in the catalytic layer according to the invention, Nickel and Cobalt, are not rare materials and allow the production of a membrane with a catalytic layer at a reasonable cost, which makes it possible to produce hydrogen on a large scale at a reasonable cost.

[0013] The invention also relates to an anionic conductive membrane comprising at least one catalytic layer as described above, a cell comprising an anionic conductive membrane and a water electrolysis installation comprising an anionic conductive membrane.

[0014] The invention finally relates to a method for depositing a catalytic layer as described above on an anionic conductive membrane. Presentation of figures

[0015] The invention will be better understood, and other characteristics and advantages of the invention will appear in light of the following description of examples of implementation of the invention. These examples are given without limitation. The description should be read in relation to the appended drawings in which: • [Fig. 1] shows a cell suitable for water electrolysis application • [Fig. 2] shows a simplified diagram of a water electrolyser • [Fig. 3] shows the size dispersion of a component used for implementing the invention, • [Fig. 4] shows an intermediate result of a method according to the invention • [Fig. 5] shows results of tests carried out with layers of catalytic material according to the invention. Detailed description

[0016] As previously stated, the invention relates to a layer of catalytic material and an anionic conductive membrane 10 for an electrochemical device. Said membrane can be used to produce a cell for an electrochemical device, for example a water electrolysis installation; the cell comprises: - a 30 anode - a cathode 20 and - between the anode and the cathode, a membrane 10.

[0017] The membrane comprises a main layer known elsewhere. The main layer is for example a main layer comprising metal oxide particles such as zirconium oxide and yttrium oxide such as that described in D2, or a main layer comprising ceramic particles such as that described in D1.

[0018] Unless otherwise specified locally, the following terms are defined here for the entire description. A "particle" is an agglomeration of several atoms or molecules of the same or different components. The "size" of a particle corresponds to the value of its largest dimension; for example, the largest dimension of a particle of approximately rhomboidal shape is its length. The numerical values given correspond to average values measured on a batch of particles of the same nature. Measurements of the size of nanoparticles can be carried out by scanning electron microscopy (SEM) or by transmission electron microscopy (TEM). The term "nanoparticles" corresponds to particles whose average size value is between 1 and 100 nm. The expression "submicron particles" corresponds to particles with an average size between 0.010 pm and 1 pm and the term “microparticles” corresponds to particles of average size between 1 pm and 10 pm.

[0019] Unless otherwise specified locally, the term "nanoparticles" is used here and throughout the description to refer to particles with an average size value between 1 and 100 nm, where size is defined as the largest dimension of a particle. Nanoparticle size measurements can be performed by scanning electron microscopy (SEM) or transmission electron microscopy (TEM). Each nanoparticle is an agglomeration of several atoms or molecules of the same or different components.

[0020] To compare membrane performance, R, the HHV (High Heating Value) efficiency of a water electrolysis cell including the membrane, is calculated. To do this, with the membrane placed in the test cell, a current density I is imposed between the cathode and the anode per unit area of membrane and the voltage V (T, I) is measured between the cathode and the anode of the cell. For a given current density, we seek to obtain the lowest possible voltage to obtain the dissociation of a given quantity of water molecules.

[0021] The minimum theoretical voltage for water dissociation reactions to begin is V0 = 1.48V HHV and, by convention, corresponds to an efficiency R of 100% HHV. The efficiency R is calculated by the relation R = V0 / V(T, I), where V(T, I) is the voltage across the cell, for a given temperature T and a given current density I.

[0022] Since the heat produced by electrolysis itself allows the temperature to be increased and then the system to be maintained at a constant temperature, the efficiency calculation above accurately reflects the efficiency of a cell. To calculate the overall efficiency of an electrolyser including such a cell, the amount of energy consumed for the overall operation of the system should be subtracted from the energy consumed directly by electrolysis. In this document, only the efficiency of the cells is analysed.

[0023] One embodiment of the invention relates to a layer of catalytic material adapted to be positioned on the main layer of the membrane, on the cathode side. The layer of catalytic material here comprises nanoparticles of components active (in the sense of catalysts for the electrolysis reaction) which are Nickel, Cobalt or a mixture of Nickel and Cobalt. The nanoparticles of active components used for the implementation of the invention can be purchased from a catalog; for example, for the tests carried out, the nanoparticles of Nickel, Molybdenum, Cobalt were purchased from the Chinese company HEBEI Fiance Nanotechnoloy Co. Ltd.

[0024] The nanoparticles of the active components are preferably supported by carbon particles and bound by the polymer binder; the carbon is, for example, in the form of activated carbon or graphite. The carbon particles are preferably micron-sized (1 μm to 100 μm) or submicron-sized (0.01 to 1 μm). The carbon particles are commercially available and can be purchased from a catalog. For example, activated carbon particles can be purchased from SigmaAldrich or Cabot Corp; for example, for some tests, Vulcan XC-72R particles of the Vulcan brand from Cabot Corp were used; they have an average size of about 0.60 μm and the size dispersion of a batch of these particles is shown in Fig. 3.

[0025] In the carbon particle / nanoparticle mixture of active components, for 100% by weight of the mixture, the proportion of carbon is 40% to 80% by weight and the proportion of active components is 20% to 60% by weight. The use of carbon particles to support the particles of active components further improves the specific surface area of the catalytic material layer. Carbon, and in particular activated carbon, itself has a large specific surface area. With the proportions indicated above, a catalytic layer with a specific surface area equal to 250 m is obtained. 2 / g at 370 m 2 / g. It is recalled that the specific surface area (or mass area) represents the total surface area per unit mass accessible to atoms and molecules for the reaction, including open porosities. The physical principle, universally recognized for the determination of the specific surface area, is based on the adsorption of gases at low temperature. Also, the use of carbon particles contributes to the good distribution of the active component nanoparticles in the catalytic layer (fig. 4) and further improves the accessibility of the chemical reaction sites on the active component particles; in fact, this facilitates on the one hand the circulation of the electrolyte between the active component nanoparticles and on the other hand the evacuation of the gases produced on these sites.

[0026] In terms of efficiency for water electrolysis, good HHV efficiencies have been obtained with a membrane comprising a catalytic layer in which the nanoparticles of active components in the catalytic material layer comprise, for 100% by weight of nanoparticles, 65 to 85% by weight of Nickel nanoparticles and 15 to 35% by weight of Cobalt nanoparticles, and better, with 70 to 80% by weight of Nickel nanoparticles and 20 to 30% by weight of Cobalt nanoparticles. With a membrane having a catalytic material layer at the cathode comprising a mixture of nanoparticles of active components comprising 75% by weight of Nickel and 25% by weight of Cobalt, an HHV efficiency of 80% has been obtained for a current density of lA / cm 2 and an efficiency of 85% HHV was obtained for a current density of 0.7A / cm 2 applied between the electrodes of the test cell.

[0027] Figure 5 shows test results allowing assessment of the evolution over time of the efficiency of the cell with a catalytic layer according to the invention. The tests are carried out with the test cell described above comprising a 30 cm membrane. 2 , a nickel cathode and a stainless steel anode; the electrolyte used is potassium hydroxide KOH at a concentration of 4 mol / l; the membrane is composed of Yttria-containing zirconia with a PTFE binder, covered on the cathode side with a catalytic layer. The tests were carried out at a temperature T = 90°C, an applied current density of 0.7A / cm2 and over a period of several tens of hours. The light gray curve shows the evolution of the voltage for a membrane comprising, on the cathode side, a catalytic layer comprising 60% carbon and 40% active nanoparticles comprising 100% nickel. The dark gray curve shows the evolution of the voltage for a membrane comprising, on the cathode side, a catalytic layer comprising 60% carbon and 40% active nanoparticles comprising 80% Nickel and 20% Cobalt. At start-up, the first hour, the catalytic activity of the catalytic layer comprising only Nickel is higher (the voltage, approximately 1.85V, is lower) than the catalytic activity of the catalytic layer comprising Nickel and Cobalt (voltage approximately 1.91V. Over time, it is observed that the catalytic activity of the catalytic layer comprising only Nickel increases progressively: from approximately 1.88V after approximately 10 hours, the voltage increases to approximately 1.92V after approximately 250 hours. The efficiency thus decreases progressively over time. On the contrary, surprisingly, the catalytic activity of the catalytic layer comprising Nickel and Cobalt gradually decreases and stabilizes: from approximately 1.91V at start-up, the voltage decreases to 1.88V after approximately 10 hours, decreases again and stabilizes at a value of approximately 1.875V which is still maintained after approximately 250 hours. The combination of Nickel and Cobalt thus makes it possible to obtain better efficiency and stable performance over time.

[0028] The performance of membranes depends in particular on the quantity of nanoparticles present in the catalytic layer. The best performance has been obtained for membranes in which the layer of catalytic material comprises, on the surface, 0.1 to 6 mg / cm 2 of nanoparticles of active components, more precisely 0.1 to 7 mg of nanoparticles in a volume corresponding to 1 cm 2 membrane surface area multiplied by the thickness of the catalytic layer. The catalytic layer preferably has a thickness of 50pm to 250pm.

[0029] The performance of membranes also depends on the catalytic activity of nanoparticles, which increases when the number of electrochemical reaction sites for dissociating water molecules increases. The sites of chemical reactions are present on the surfaces of catalytic materials. To increase the number of reaction sites on particles of active components such as Nickel and Cobalt, tests have shown that an effective solution is to increase the specific surface area of the catalytic materials. For this purpose, in the context of the invention, the nanoparticles of active components have a size of less than 50 nm, preferably less than 20 nm and even more preferably less than 5 nm. The particles have a generally substantially spherical or convex polyhedral shape and their size corresponds to their largest dimension. The tests also showed that, for a given particle size, the catalytic activity of the particles is improved by improving the homogeneity of the particle size; this is true when the particles comprise a mixture of active component particles, and even more true when the particles comprise active component particles and carbon particles. The tests have further shown that the homogeneity (in terms of particle nature) of a mixture of active component particles or a mixture of active component particles and carbon particles further improves the catalytic activity.

[0030] The performance of the membranes still depends on the good cohesion of the nanoparticles between them, the good cohesion of the catalytic layer to the main layer of the membrane and the durability of this cohesion over time. After testing, the polymer binder is an ionomer chosen according to its resistance over time in aggressive chemical environments and at high temperatures up to 120°C, but also according to its ionic conduction properties. By polymerizing, the binder acts as a glue in the catalytic layer and holds the particles and nanoparticles of this layer together. It also allows good adhesion of the catalytic layer with the membrane. Finally, an essential point in the context of the invention, due to its ionic conduction, the ionomer allows the catalytic layer to remain electrically and ionically conductive.The preferred ionomer is known as Nafion®, derived from the polymerization of a monomer called tetrafluoroethylene-perfluorosulfonic acid. The proportion of polymer binder is 10% to 40% of the weight of the binder / active component particle mixture (or where appropriate, the binder / active component particle + carbon particle mixture).

[0031] The performance of the membranes also depends on the method of producing the catalytic layer on the main layer of the membrane.

[0032] To this end, the invention provides a method for depositing a catalytic layer on an anionic conductive membrane, the catalytic layer comprising nanoparticles of at least two active components and a polymer binder, the method comprising a step of preparing a liquid ink comprising nanoparticles and a polymer binder, the nanoparticles comprising particles of at least two active components; the step of preparing the liquid ink comprises the following steps consisting of: - mixing the nanoparticles in a liquid, the liquid being water, a solvent or a mixture of water and solvent, the solvent being for example an alcohol, - grind the mixture of particles in a liquid medium until a mixture is obtained homogeneous, - add the liquid polymer binder.

[0033] In the example of the catalyst according to the invention, the particles of the active components are nickel particles and cobalt particles.

[0034] The liquid is water, a solvent, or a mixture of water and solvent. The solvent is suitable for diluting the binder. The solvent is, for example, an alcohol. Successful tests have been carried out, for example, with water, with ethanol, with a mixture of water and isopropanol.

[0035] The quantity of liquid chosen is adapted to wet the solid nanoparticles, so as to facilitate the following grinding step and to limit an operator's exposure to the nanoparticle dust which will be generated during the grinding step. The amount of liquid is also chosen so that the resulting ink can be projected onto the membrane. In the successful tests carried out, a quantity of liquid was used whose weight corresponded to 10 to 25 times the weight of the solid particles.

[0036] The grinding of nanoparticles is carried out in an aqueous medium, for example in a planetary mill / mixer (or ball milling in English). Grinding a mixture of particles of at least two different components (one can also speak of co-grinding) makes it possible to obtain smaller nanoparticles, of the chosen size, less than 50 nm, preferably less than 20 nm and even more preferably less than 5 nm, and particles of the most homogeneous average size possible.

[0037] In the method according to the invention, the grinding makes it possible to obtain a ground material comprising not only particles comprising atoms or molecules of the first active component, and particles comprising atoms or molecules of a second active component but also, and this surprisingly, particles comprising atoms or molecules of two (or more) different active components. For example, the grinding of a mixture of Nickel particles and Cobalt particles makes it possible to obtain a ground material comprising Nickel particles, Cobalt particles and particles of a Ni-Co alloy. The grinding thus makes it possible to physically agglomerate particles together by physically compressing the particles against each other. The ground material obtained thus has a greater catalytic activity than the mixture of particles before grinding.

[0038] The mixing of nanoparticles in the liquid also allows for a homogeneous mixture (in terms of distribution of particles of different natures) of the materials, particularly when two or more types of nanoparticles are used (for example Nickel and Cobalt here, or Nickel, metal oxide and / or Molybdenum or even platinum, copper, zinc).

[0039] If carbon is used to support the active component nanoparticles, the preparation step also includes, before the addition of the polymer binder, the following steps: - adding carbon particles to the ground nanoparticles of active components and - grind the mixture of active component particles and carbon particles until a homogeneous mixture is obtained.

[0040] Carbon is for example in the form of activated carbon or graphite, particles of the order of 0.2 to 0.9 pm.

[0041] This second grinding step allows the active component nanoparticles to be incorporated into the carbon particles with a large specific surface area. It allows the size of the carbon particles and the active component particles to be homogenized, and it also allows the active component particles to be well distributed among the carbon particles and to adhere better to the carbon particles. This step can also be carried out with a support material other than carbon.

[0042] After adding the polymer binder, a mixing step is carried out to obtain a homogeneous ink.

[0043] The preparation step described above makes it possible to obtain an ink comprising suspended catalytic nanoparticles, a composition which will also be called “catalytic ink”.

[0044] The catalytic ink thus prepared is sprayed by ultrasound onto the main layer of an anionic conductive membrane. The deposition of the catalytic ink by an ultrasonic spraying process, combined with the fluidity of the ink, allows the nanoparticles to be well separated from each other to avoid their agglomeration during spraying. This process also allows the ink to be kept homogeneous throughout the spraying. This spraying process also allows, through a pressure effect, to obtain good adhesion of the ink to the main layer of the membrane. The result is a catalytic layer where the distribution of the nanoparticles is particularly homogeneous and regular; also, the layer obtained has a very low thickness, of the order of 50pm to 250pm at the cathode for a layer comprising Nickel, Cobalt and Carbon, and particularly constant over the entire surface of the membrane.Finally, this process makes it possible to obtain a porous catalytic layer which thus presents a large specific surface area (ratio between the active surface area and the weight of the catalytic layer), from 5m2 / g to 200m2 / g depending on the formulation of the catalytic ink.

[0045] After complete drying, the membrane can be stored. Drying allows the liquid, water or a mixture of water and solvent, to evaporate. The catalytic layer deposited on the membrane then comprises only the particles bound by the polymer binder.

[0046] The method according to the invention can be implemented to deposit a first catalytic layer on a first face of the main layer of the membrane, then optionally a second catalytic layer on a second face of the main layer of the membrane.

[0047] Thus, the method according to the invention can be implemented to produce an anionic conductive membrane 10 comprising a main layer covered by: - a layer of a first catalytic material comprising nanoparticles of active components bound by a polymer binder, the active components being Nickel and Cobalt - or, on one side of the main layer, by a layer of the first catalytic material and on the other side of the main layer by a layer of a second catalytic material. The second catalytic material comprises, for example, nanoparticles of active components bound by a polymer binder, the active components being Nickel, a metal oxide and / or Molybdenum.

[0048] Figure 1 shows a diagram of a cell suitable for a water electrolysis plant for the production of gaseous hydrogen H2 and oxygen O2. The cell comprises a cathode 20, an anode 30 and between the two a membrane 30. Figure 2 shows a schematic diagram of a water electrolysis plant comprising a cell according to the invention. The membrane 10 divides a bath into two, a bath comprising a solution of water and electrolyte, in one example potash KOH. The membrane is covered on one side by a layer 40 of catalytic material comprising nanoparticles of nickel and cobalt supported by activated carbon and on the other side by a layer 50 of catalytic material comprising nanoparticles of nickel and molybdenum. The cathode 20 and the anode 30 are positioned on either side of the membrane and are connected respectively to the negative and positive terminals of an electrical energy source.The membrane 10 allows a good separation of the hydrogen gas produced on the cathode and the oxygen gas produced on the anode. The cathode and the anode are metallic, for example nickel, respectively stainless steel. With such a membrane, with a main layer based on zirconia and with two layers of catalytic material on either side of the main layer, an efficiency of 84% HHV was obtained for a current density of 1A / cm. 2 and an efficiency of 90%HHV was obtained for a current density of 0.7A / cm 2 applied between the cell electrodes.

[0049] A single cell is shown in Figure 1. However, in practice, an industrial installation can include several cells, or even a hundred cells.

Claims

Claims

1. Layer of catalytic material for an anionic conductive membrane (10) for an electrochemical device, layer of catalytic material comprising nanoparticles of active components bound by a polymer binder, the active components being Nickel and Cobalt.

2. A layer of catalytic material according to claim 2 wherein the active components comprise 65 to 85% by weight of Nickel and 15 to 35% by weight of Cobalt, preferably 70 to 80% by weight of Nickel and 20 to 30% by weight of Cobalt, and even more preferably 75% by weight of Nickel and 25% by weight of Cobalt.

3. A catalytic material layer according to either of claims 1 or 2 wherein the active component nanoparticles are supported by carbon particles, the active component nanoparticles and the carbon particles being mixed and bound by the polymer binder.

4. A layer of catalytic material according to claim 3 wherein the carbon is in the form of activated carbon or graphite.

5. Layer of catalytic material according to one of claims 3 or 4 in which the mixture of active components and carbon comprises: - 40% to 80% by weight of carbon and - 20 to 60% by weight of active components.

6. Layer of catalytic material according to one of claims 3 or 4 comprising: - 60% to 90% by weight of active components or a mixture of active components and carbon, in the form of particles, - 10 to 40% by weight of binder.

7. Layer of catalytic material according to one of claims 1 to 3 comprising, on the surface, 0.1 to 6 mg / cm 2 of active components.

8. Layer of catalytic material according to one of claims 1 to 4 in which the polymer binder is an ionomer, preferably a fluoropolymer copolymer based on tetrafluoroethylene sulfonate (Nation).

9. Layer according to one of claims 1 to 5 in which the nanoparticles of active components and / or the carbon nanoparticles have a size less than 50 nm, preferably less than 20 nm and even more preferably less than 5 nm.

10. Anionic conductive membrane (10) for an electrochemical device, membrane comprising a main layer covered by a layer of catalytic material according to one of claims 1 to 9- or, on one side, by a layer of catalytic material according to one of claims 1 to 9 and on the other side by a layer of a second catalytic material.

11. Method of depositing a catalytic layer on a main layer of an anionic conductive membrane, catalytic layer comprising nanoparticles of at least two active components and a polymer binder, method comprising a step of preparing a liquid ink comprising the following steps: - mixing the nanoparticles of active components in a liquid, the liquid being water, a solvent or a mixture of water and solvent, the solvent being for example an alcohol, - grinding the mixture of nanoparticles of active components and liquid, - add the polymer binder to the ground material and mix.

12. A method according to claim 11, wherein the preparing step also comprises, before adding the polymer binder, the following steps: - adding carbon particles to the ground nanoparticles of active components and - grind the mixture of active component particles and carbon particles until a homogeneous mixture is obtained.

13. Method according to one of claims 8 to 9 also comprising a step of ultrasonic spraying of said liquid ink onto the main layer of the anionic conductive membrane.

14. Cell for an electrochemical device, cell comprising: - an anode (30) - a cathode (20) and - between the anode and the cathode, a membrane (10) according to claim 10.

15. Water electrolysis installation comprising at least one cell according to the preceding claim.

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