ES2932991B2 - ELECTROCHEMICAL DEVICE FOR GENERATION OF ELECTRICITY AND/OR HYDROGEN - Google Patents

Description

DESCRIPTION

ELECTROCHEMICAL DEVICE FOR GENERATION OF ELECTRICITY AND/OR HYDROGEN

TECHNIQUE SECTOR

The present invention belongs to the technical field of electrochemical devices. More particularly, it belongs to the technical field of electrochemical devices that allow generating an electric current from a spontaneous chemical reaction that takes place in an electrochemical cell fed with a fuel and an oxidant (known as a fuel cell, in English "fuel cell"). ), and/or that allow energy to be stored in the product of a chemical reaction caused by electrical energy applied to two electrodes of an electrochemical cell fed with a suitable precursor (known as an electrolyzer, "electrolyser").

More particularly, it belongs to the technical field of electrochemical devices capable of developing both functions, fuel cell and electrolyzer, without more than changing the operating conditions, also known as reversible or regenerative fuel cells. For example, reversible fuel cells that operate at a temperature below 100 oC, and in which the fuel is preferably hydrogen, the oxidant is oxygen from the air, and the precursor is water, ultimately capable of carrying carry out the reaction H2+0.5O2^ H2O in both directions.

BACKGROUND OF THE INVENTION

Systems with reversible fuel cells are already known. For example, EP1665441A2 discloses a reversible high or low temperature system in which the same cell can function as a fuel cell to generate electricity and as an electrolyzer to generate a fuel. While at high temperature this dual functionality can involve different types of fuel (hydrogen, methane, methanol, among others), at low temperature the kinetic difficulties restrict this possibility to hydrogen fuel, and it is also necessary that the electrodes contain an electrocatalyst to be able to combine both fuel cell and electrolyzer functionalities. However, low temperature operation is more suitable in certain applications, such as energy generation and storage systems that take advantage of renewable energies such as photovoltaics or wind. It would be desirable to improve the power density and reduce the cost of these low temperature reversible fuel cell systems.

Reversible fuel cells that use mediating reagents to be able to perform both functions are already known, such as, for example, the one disclosed in WO2019149770A1. It would be desirable to improve the efficiency, simplify the system, and expand the functionality of these reversible fuel cells.

Low-temperature reversible systems and cells for hydrogen production and consumption are already known, such as EP2833469A1, EP1665441A2, WO2021095243A1, WO2019149770A1, WO2007091050A1, - KR101955364B1 (A), in which electrodes that can operate reversibly are used. This simplifies the system but increases catalyst costs, especially in the reversible oxygen electrodes, which must be bi-functional, that is, capable of catalyzing the two reactions: reduction of oxygen for operation as a fuel cell, and oxidation of water. for operation as an electrolyzer. In acidic medium, which is the most common and efficient, the catalysts must be composite materials based on Pt nanoparticles together with particles of another material, such as Ir, IrO2, Ru-Ir, RuO2, IrO2-RuO2, IrO2/RuO2, Irx(IrO2)10-x Pt/TiO2y Ir/TiO2, which considerably increase the cost of the electrode, as well as decrease the efficiency and durability of the electrodes due to the physical-chemical conditions imposed by their reversible functionality. It is desirable to maintain the reversible activity of the device without affecting its cost, efficiency and durability.

GENERAL DESCRIPTION OF THE INVENTION

The present invention seeks to solve problems presented by prior art disclosures such as those mentioned above.

The present invention relates to an electrochemical device for generating electricity from hydrogen and oxygen, and/or for generating hydrogen and oxygen from water and electricity. For example, it refers to a low temperature electrochemical device. An example of a low temperature electrochemical device is an electrochemical device configured to operate in a range of at least 10 oC and at most 80 oC when using a perfluorinated polymer membrane with polar sulfonate groups as an electrolyte. The special configuration of its electrodes, in which two passively fed oxygen electrodes face the same hydrogen electrode, allows an improvement in power density, simplicity of electrocatalysis, lower volume and weight of the system, and greater functionality. . In particular, the use of expensive reversible catalysts is not necessary, and both fuel cell and electrolyzer functions can be carried out simultaneously. The device comprises two oxygen gas diffusion electrodes facing the same central hydrogen gas diffusion electrode on their faces. The two electrodes facing the central electrode function according to the oxygen reduction reaction (O2+ 4H<+>+ 4e- →2H2O) or the water oxidation reaction (H2O → 0.5O2+ 2H+ 2e-) and each of them can function according to a different reaction than that of the other electrode. The central electrode works reversibly according to the hydrogen reaction H2^ 2H+ 2e-. This configuration allows the same electrochemical device to function simultaneously as a fuel cell to produce electricity and as an electrolyzer to produce hydrogen. In the passive feeding of the present device, the supply of reagents to the electrodes is carried out passively by natural forces such as, for example, diffusion and/or capillarity without requiring forced convection generators such as, for example, fans and/or pumps.

A first aspect of the present invention relates to an electrochemical device for generating hydrogen and/or electric current, the electrochemical device comprising a first gas diffusion electrode, a second gas diffusion electrode and a third gas diffusion electrode; being the first electrode for hydrogen diffusion; the second electrode and the third electrode being for oxygen diffusion; the first electrode being in a compartment; the electrochemical device comprising a first current collector, a second current collector and a third current collector; the compartment being laterally delimited by a first electrolyte membrane and by a second electrolyte membrane; the first electrode being between the first electrolyte membrane and the second electrolyte membrane, the first electrode being in contact with the first electrolyte membrane and with the second electrolyte membrane and the first electrode being in contact with the first current collector; the second electrode being between the first electrolyte membrane and the second current collector; the third electrode being between the second electrolyte membrane and the third current collector; the second electrode being in contact with the first electrolyte membrane and with the second current collector; the third electrode being in contact with the second electrolyte membrane and with the third current collector.

This configuration of an electrochemical device in which a second electrode and a third electrode are connected to a first electrode by means of electrolyte membranes allows the electrochemical device to:

• generate electrical energy using the first electrode and the second electrode as a first fuel cell and simultaneously generate electrical energy using the first electrode and the third electrode as a second fuel cell;

• generate electrical energy using the first electrode and the second electrode as a first fuel cell and simultaneously generate hydrogen using the first electrode and the third electrode as an electrolyzer; either

• generate hydrogen using the first electrode and the second electrode as a first electrolyzer and simultaneously generate hydrogen using the first electrode and the third electrode as a second electrolyzer.

Therefore, in using the second electrode and the third electrode to reduce oxygen and generate electrical energy, as the same first electrode is shared to oxidize hydrogen, it is possible to increase the electrical power density of the electrochemical device compared to a fuel cell. conventional, which would require a total of four electrodes instead of three: two anodes and two cathodes. In the same way, the electrolyzing function is improved when the second and third electrodes are used to oxidize water simultaneously, since hydrogen is generated at twice the rate in the first electrode compared to an electrolyzer that included the first electrode and the second electrode and did not understand the third electrode.

Furthermore, the electrochemical device of the first aspect of the present invention allows a first electrode, a second electrode and a third electrode to be used to simultaneously generate electrical energy and hydrogen. Unlike a conventional reversible fuel cell, both functions do not interfere and can take place simultaneously, as the oxidation of hydrogen and the reduction of protons (or water in a neutral-basic medium) occur in the same first electrode, while the Respective complementary reactions, that is, the reduction of oxygen and the oxidation of water, occur separately in a second electrode and in a third electrode, respectively, or vice versa. In this way both functions can take place simultaneously in the same electrochemical device.

The different configurations of the electrochemical device object of this invention, as a fuel cell with two cathodes and an anode, as an electrolyzer with two anodes and a cathode, or as a fuel cell and electrolyzer sharing a first electrode, are possible thanks to the reversible nature of the electrochemical reaction of hydrogen H2^ 2H+ 2e- that allows this reaction to proceed at high speed in both directions on a first electrode, with the same catalyst and preferably in an acidic medium.

The electrochemical device of the first aspect of the present invention can be configured to generate up to 3 W of electrical power in an active area of 12.6 cm2. The generating electrical power can be increased by increasing the active area and/or by electrically connecting various electrochemical devices.

Furthermore, the configuration of the electrodes of the electrochemical device gives it the possibility of operating passively, that is, feeding the different reagents (ambient air, hydrogen, water) without forced convection, reducing auxiliary components compared to conventional electrochemical devices, which, in general, is very convenient for small portable devices.

The compartment where the first electrode is located is a compartment that also serves to store hydrogen produced by the device.

To allow the second electrode to function as an electrolyzer, the second electrode must be in contact with water, for example, submerged in water. To allow the third electrode to function as an electrolyzer, the third electrode must be in contact with water, for example, submerged in water.

In some embodiments, the second electrode and/or the third electrode comprise(s) a catalyst for oxidizing water; The first electrode preferably comprises a catalyst for reducing water or protons. These embodiments make it possible to accelerate the oxidation of water in the second and/or third electrode and, preferably, the reduction of water or protons in the first electrode, giving rise to the electrolysis of water, by applying electrical energy between the first electrode and the second. electrode and/or by applying electrical energy between the first electrode and the third electrode. The electrolysis of water makes it possible to obtain hydrogen at the first electrode. The reaction is 2H+ 2e- → H2 in an acidic medium, while in a neutral or basic medium it is H2O 2e- → H2+ 2OH-.

In some embodiments, the second electrode comprises a catalyst for oxidizing water and the third electrode comprises a catalyst for reducing oxygen; The first electrode preferably comprises the same catalyst to oxidize hydrogen and to reduce water or protons. These embodiments make it possible to accelerate the reduction of oxygen at the third electrode and the oxidation of hydrogen at the first electrode produced by using the first electrode and the third electrode as a fuel cell. Furthermore, these embodiments allow accelerating the oxidation of water at the second electrode and the reduction of water or protons at the first electrode produced by using the first electrode and the second electrode to cause electrolysis of water.

In some embodiments, the second electrode and/or the third electrode comprise a catalyst for reducing oxygen; The first electrode preferably comprises a catalyst for oxidizing hydrogen. These embodiments make it possible to accelerate the reduction of oxygen in the second and/or third electrode and, preferably, the oxidation of hydrogen in the first electrode produced by using the first electrode and the second electrode as a fuel cell and/or using the first electrode and the third electrode as a fuel cell.

In some embodiments, the catalyst for oxidizing water comprises at least one of a platinum-ruthenium alloy oxide, a platinum-iridium alloy oxide, a ruthenium oxide, an iridium oxide, and a nickel oxide; the second electrode comprising a metal substrate, the substrate having pores. Electrodes with this catalyst are sufficiently resistant to oxidation, have a relatively high porosity and can withstand relatively high electrical voltages.

In some embodiments, the oxygen reducing catalyst comprises carbon (e.g., a microporous carbon such as carbon black) coated with platinum nanoparticles with a concentration of at least 0.1 and at most 0.3 mg of platinum per projected square centimeter. of electrode (projected geometric area), or the catalyst for reducing oxygen comprises nickel and/or a porous solid material based on carbon doped with nitrogen and iron, the porous solid material based on doped carbon having the formula FeCxNy. Other catalysts for reducing oxygen comprise nickel and/or porous solid materials based on N and Fe doped carbon (FeCxNy), which have lower activity and stability in acidic medium but can function well in basic medium. These catalysts are, on the other hand, more abundant and less expensive than platinum.

In some embodiments, the catalyst for reducing water or protons comprises carbon coated with platinum nanoparticles with a concentration of at most 0.2 mg of platinum per projected square centimeter of electrode (geometric or projected area). The particles are for example particles between 1 and 10 nm in size.

In some embodiments, the first electrode comprises a first face and a second face, the first face being in contact with the first electrolyte membrane and the second face being in contact with the second electrolyte membrane; optionally, the first current collector comprises a first grid and a second grid, the first grid being electrically connected to the second grid, the first face of the first electrode being in contact with the first grid and the second face of the first electrode being in contact with the second grid, and the first grid and the second grid being for conduction of electric current. Thus, the electrochemical device is configured to allow the diffusion of hydrogen from and to the first electrolyte membrane through the first face of the first electrode and is configured to allow the diffusion of hydrogen from and to the second electrolyte membrane through through the second face of the first electrode.

In some embodiments, the first grid is in contact with the second grid. In some embodiments, the first grid and the second grid are the same grid.

In some embodiments, the second current collector comprises a third grid, the third grid being in contact with the second electrode; The third grid being for conduction of electric current.

In some embodiments, the third current collector comprises a fourth grid, the fourth grid being in contact with the third electrode; being the fourth grid for conduction of electric current.

The grids of the current collectors make it possible to capture the electrical energy produced by the electrochemical device and/or provide electrical energy to the electrochemical device and at the same time allow to minimize the resistance of the current collectors to the diffusion of gases and liquid water from and towards the electrodes, since the grids have gaps through which gases and water can flow.

In some embodiments, the first electrode is hydrophobic; the first electrode being preferably superhydrophobic. In this way, the occlusion of pores of the first electrode with liquid water is minimized, which would increase the resistance to hydrogen transport and decrease the efficiency of the electrochemical device. This water comes from the reduction of oxygen in the second and third electrodes, and arrives through contact with the respective membranes. This effect is particularly favorable for function as a fuel cell, although it can also improve operation as an electrolyzer by facilitating the release of generated hydrogen.

In some embodiments, the electrochemical device comprises a first gas conduit and a second gas conduit; the first conduit being fluidically connected to the compartment and the second conduit being fluidically connected to the compartment. These embodiments allow the first conduit to be used to introduce hydrogen into the compartment where the first electrode is located and allow the second conduit to be used to extract hydrogen from the compartment, and/or for eventual air and/or water purges.

In some embodiments, the electrochemical device comprises a first plate with first columns and a second plate with second columns; the second current collector being between the first plate and the second electrode; the first columns pressing the second current collector against the second electrode; the third current collector being between the second plate and the third electrode; the second columns pressing the third current collector against the third electrode; wherein preferably the first columns comprise a hydrophilic material and/or the second columns comprise a hydrophilic material. The columns allow improving the electrical contact between the components of the electrochemical device by increasing the pressure of said contact and, at the same time, minimizing the resistance to the exchange of gas and liquid water between the second and third electrodes and the environment of the cell (environment ), since the columns leave free spaces between them through which air and liquid water can flow. The hydrophilic material of the columns facilitates the release of liquid water produced when the cell functions as a fuel cell.

The first columns and second columns are preferably arranged in the form of a matrix, which can be square, hexagonal or forming concentric circles, leaving a spacing between them of between 1 mm to 4 mm. The columns must have a diameter between 0.5mm and 5mm, and a length of not less than 0.2mm. The first and second plates and the first and second columns must be made of sufficiently light materials, with sufficient mechanical resistance to withstand the pressure they exert on the device at temperatures of up to 80 oC, such as aluminum, titanium and/or thermoplastics. To improve their hydrophilicity they can be conveniently treated with coatings, or given a porous morphology that allows the passive transport of liquid water by capillarity through them.

In some embodiments, the first plate, the second current collector, the second electrolyte membrane, the first electrolyte membrane, the third current collector and the second plate comprise through holes; the electrochemical device comprising screws and nuts coupled to the screws; the through holes being crossed by the screws; the electrochemical device being configured to regulate the pressure between the columns and the second and third current collector by operating the nuts. This pressure must be adjusted sufficiently to minimize contact resistance between components, but without unduly reducing the porosity of the electrodes and preventing the transport of gas and water through them. The nuts can be tightened to increase the contact pressure between the components of the electrochemical device and can be loosened to reduce the contact pressure between the components of the electrochemical device.

In some embodiments, the electrochemical device is detachable and mountable; the electrochemical device comprising a disassembly configuration in which:

- the second electrode is separated from the second current collector,

- the second electrode is separated from the first electrolyte membrane, - the third electrode is separated from the third current collector, and/or

- the third electrode is separated from the second electrolyte membrane.

In other words:

- the second electrode is not in contact with the second current collector, - the second electrode is not in contact with the first electrolyte membrane, - the third electrode is not in contact with the third current collector, and/or - the Third electrode is not in contact with the second electrolyte membrane.

In these embodiments, the electrochemical device is configured to be mountable after disassembly.

In some embodiments, the first membrane is polymer electrolyte and/or the second membrane is polymer electrolyte. Said electrolyte is based on polymeric solids with the capacity to contain liquid water in microchannels of its structure, which provides them with high ionic conductivity (proton or anionic) at low temperature, as well as high resistance to the passage of electrons and the passage of gases. These properties allow the development of high powers in operation as a fuel cell, as well as minimal electrical consumption in operation as an electrolyzer. In addition, polymer electrolytes have high chemical resistance under operating conditions that maximizes their durability. Examples of polymeric materials are mainly polymers based on perfluorinated chains and sulfonate groups such as, for example, Nafion® or Aquivion®, and others such as polyethylene oxide, polyimides with sulfonate groups, chitosan, sulfonated polyketones (SPEEK), or polyvinyl alcohol, as well as materials mixed or hybrid compounds, such as copolymers, polymers-inorganic solids, among others.

A second aspect of the present invention relates to an electrochemical device according to the first aspect of the invention and to a photovoltaic panel, the photovoltaic panel being electrically connected to the first current collector and to the second current collector, and/or to the first current collector. current and to the third current collector. In some embodiments, the photovoltaic panel is connected to the electrochemical device via an electronic interface such as a DC/DC converter, i.e., a DC to DC converter. This electronic interface allows the electrical characteristics of the photovoltaic panel to be adjusted to the electrical characteristics of the electrochemical device. These embodiments allow hydrogen obtained by electrolysis to be accumulated in the electrochemical device from electrical energy generated by the photovoltaic panel.

A third aspect of the present invention relates to an electrochemical device according to the first aspect of the present invention and to a wind turbine, the wind turbine being electrically connected to the first current collector and the second current collector, and/or the wind turbine being electrically connected to the first current collector and to the third current collector. In some embodiments, the wind turbine is connected to the electrochemical device via an electronic interface such as a DC/DC converter, i.e., a DC to DC converter. This electronic interface allows the electrical characteristics of the wind turbine to be adjusted to the electrical characteristics of the electrochemical device. These embodiments allow hydrogen obtained by electrolysis to be accumulated in the electrochemical device from electrical energy generated by the wind turbine.

A fourth aspect of the present invention relates to a use of the electrochemical device according to the first aspect of the invention; the second electrode being in contact with water, the third electrode being in contact with oxygen and the first electrode being in contact with hydrogen; The use comprising passing a current through the first current collector and through the second current collector so that the non-spontaneous electrochemical reaction of water dissociation (H2O ® H2+ 0.5O2) takes place and hydrogen is generated in the compartment; and the use comprising the spontaneous electrochemical reaction of hydrogen and oxygen to generate water (H2+ 0.5O2® H2O) between the third electrode and the first electrode, said electrochemical reaction generating an electric current between the first current collector and the third current collector. current. In this way, the electrochemical device is used as a fuel cell and simultaneously as an electrolyzer, that is, electric current and hydrogen are generated simultaneously. More specifically, the first electrode simultaneously participates in electrolysis and in the generation of electrical energy.

A fifth aspect of the present invention relates to a use of the electrochemical device according to the first aspect of the invention in which the second electrode and the third electrode are in contact with water, the first electrode being in contact with hydrogen; the use comprising the electrochemical reaction H2O ® H2+ 0.5O2 between the second electrode and the first electrode and the same electrochemical reaction H2O ® H2+ 0.5O2 between the third electrode and the first electrode, generating the electrochemical reaction hydrogen in the compartment. This causes electrolysis of water (H2O ® H2+ 0.5O2) so that hydrogen is generated in the compartment.

A sixth aspect of the present invention relates to a use of the electrochemical device according to the first aspect of the present invention; the second electrode and the third electrode being in contact with oxygen, and the first electrode being in contact with hydrogen; the use comprising the electrochemical reaction H2+ 0.5O2® H2O between the second electrode and the first electrode and the same electrochemical reaction between the third electrode and the first electrode, the electrochemical reaction generating an electric current in the second current collector and in the third current collector.

In some embodiments, the photovoltaic panel and/or the wind turbine is electrically connected to the first current collector and to the second current collector and/or the photovoltaic panel and/or the wind turbine is electrically connected. s) to the first current collector and to the third current collector.

The electrochemical device according to the first aspect of the invention is very suitable for carrying out laboratory performance studies of catalysts, fuel cell components and electrolyzer components.

The different aspects and embodiments of the invention defined above can be combined with each other, as long as they are mutually compatible.

Additional advantages and features of the invention will become apparent from the following detailed description and will be particularly noted in the appended claims.

BRIEF DESCRIPTION OF THE FIGURES

In order to help a better understanding of the characteristics of the invention according to examples of practical embodiments thereof, a set of drawings is attached as an integral part of the description in which, for illustrative purposes, the following has been represented. following:

Figure 1 shows an electrochemical device according to some embodiments of the invention.

Figure 2 shows an exploded view of components of an electrochemical device according to some embodiments of the invention.

Figure 3 shows an exploded view of an intermediate portion of an electrochemical device according to some embodiments of the invention.

Figure 4 shows a first electrode and a compartment cover of an electrochemical device according to some embodiments of the invention.

Figure 5 shows a first electrode, a first current collector and a holder for the first electrode of an electrochemical device according to some embodiments of the invention.

Figure 6 shows a second electrode, a third electrode, a second current collector and a third current collector of an electrochemical device according to some embodiments of the invention.

Figure 7 shows a clamping and pressure structure of an electrochemical device according to some embodiments of the invention.

Figure 8 shows an electrochemical device according to some embodiments of the invention in air.

Figure 9 shows an electrochemical device according to some embodiments of the invention immersed in water.

Figure 10 shows an electrochemical device according to some embodiments of the invention partially immersed in water.

Figure 11 shows a graph that represents an evolution of voltage, current and power of an electrochemical device according to some embodiments of the invention.

Figure 12 shows a graph in which a temporal evolution of current of an electrochemical device is represented in accordance with some embodiments of the invention.

Figure 13 shows a graph in which a temporal evolution of electrical power of an electrochemical device is represented in accordance with some embodiments of the invention.

Figure 14 shows a graph in which a temporal evolution of current of an electrochemical device is represented in accordance with some embodiments of the invention.

Figure 15 shows a graph in which a temporal evolution of electrical power of an electrochemical device is represented in accordance with some embodiments of the invention.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

In view of this description and figures, the person skilled in the art will be able to understand that the invention has been described according to some preferred embodiments thereof, but that multiple variations can be introduced in said preferred embodiments, without leaving the object of the invention as such. and how it has been claimed.

Figure 1 shows an electrochemical device 100. Figure 2 shows the electrochemical device 100 of Figure 1 without some components of pressure and holding elements 101 of the electrochemical device 100. Figure 3 shows an intermediate portion 102 of the electrochemical device 100.

The electrochemical device 100 is an electrochemical device configured to produce electrical energy from a chemical combustion reaction and/or to produce a fuel through a chemical reaction based on electrolysis, the reaction being chemical (the direct meaning indicates the combustion reaction while that the reverse direction indicates the electrolysis reaction):

H2+0.5O2^ H2O

Continuing with Figures 1, 2 and 3, the electrochemical device 100 comprises an intermediate portion 102. The intermediate portion 102 comprises a first gas diffusion electrode 1, specifically, an electrode for hydrogen diffusion. The first electrode 1 is, for example, a porous carbon cloth or carbon paper electrode coated with a catalyst. The catalyst comprises, for example, platinum or, more particularly, platinum nanoparticles supported by carbon or other conductive and stable material. An example of a suitable concentration of platinum for oxidizing hydrogen is a concentration of at least 0.02 mg of platinum per square centimeter of projected surface of the first electrode 1 and at most 0.20 mg of platinum per square centimeter of projected surface of the first electrode 1.

Figure 5 shows a first face 11 and a second face 12 of the first electrode 1. The first electrode 1 delimits an interior compartment between the first face 11 and the second face 12. The first face 11 and the second face 12 of the first electrode 1 They may be joined by a segment made of the same material as the first face 11 and the second face 12 of the first electrode 1, as illustrated in Figure 5. In other embodiments (not illustrated), the first face 11 and the second face 12 are not joined by a segment. The first current collector 2 is partially housed in the inner compartment.

As can be deduced from Figures 4 and 5, the first current collector 2 comprises a first conductive face 22, a second conductive face 23 and a first conductive projection 21. The first conductive face 22 and the second conductive face 23 are housed in the interior compartment. The first conductive face 22 is in contact with the first face 11 of the electrode, and the second conductive face 23 is in contact with the second face 12 of the electrode. In other embodiments (not illustrated) the relative arrangement between the first electrode 1 and the first current collector 2 is different from that illustrated in Figures 4 and 5.

The first conductive face 22 is, for example, a grid. The first conductive face 22 is made of an electrically conductive material such as nickel. To improve the protection of the first conductive face 22 against corrosion and/or improve the electrical contact between the first conductive face 22 and the first face 11 of the electrode, the first conductive face 22 can be coated with a material such as, for example, gold. or coal.

The first face 11 of the first electrode 1 is hydrophobic or, more particularly, superhydrophobic, to facilitate the use of the first electrode 1 as a fuel cell and as an electrolyzer. The hydrophobic character allows this use to be facilitated because it repels the liquid water that is in the electrochemical device, such as the water produced in the second electrode 81 and/or in the third electrode 82 in operation as a fuel cell, and/or the water in contact with the second electrode 81 and/or the third electrode 82 in operation as an electrolyzer. This prevents the first electrode 1 from flooding to avoid hindering the transport of hydrogen. A first hydrophobic or, more particularly, superhydrophobic, face 11 comprises, for example, platinum deposited by electrospray (or electrospray) supported by carbon on the first face 11 and/or a hydrophobicizing agent such as, for example, Teflon (PTFE) deposited on the first side 11.

The second conductive face 23 is, for example, a conductive grid. The second conductive face 23 is made of an electrically conductive material such as nickel. To improve the protection of the second conductive face 23 against corrosion and/or improve the electrical contact between the second conductive face 23 and the second face 12 of the electrode, the second conductive face 23 can be coated with a material such as, for example, gold or coal.

The second face 12 of the first electrode 1 is hydrophobic or, more particularly, superhydrophobic, to facilitate the use of the first electrode 1 as a fuel cell and as an electrolyzer. The hydrophobic character allows this use to be facilitated because it repels the liquid water that is in the electrochemical device, such as the water produced in the second electrode 81 and/or in the third electrode 82 in operation as a fuel cell, and/or the water in contact with the second electrode 81 and/or the third electrode 82 in operation as an electrolyzer. This prevents the first electrode 1 from flooding to avoid hindering the transport of hydrogen. A second hydrophobic or, more particularly, superhydrophobic, face 12 comprises, for example, platinum deposited by electrospray on the second face 12 and/or a hydrophobicizing agent such as, for example, Teflon (PTFE) deposited on the second face 12.

The first conductive projection 21 is of the same grid material as the second conductive face 23 and the first conductive face 22, and electrically connects the second conductive face 23 and the first conductive face 22 to the exterior of the electrochemical device. The first conductive projection 21 allows the electrochemical device 100 to be connected to an external electrical circuit.

Continuing with Figure 5, the first electrode 1 comprises a support 2b housed in the interior compartment. The support 2b is, for example, a porous piece and/or with through holes to allow the passage of hydrogen through the support 2b.

To facilitate the transportation of a product, such as water, generated by the operation of the electrochemical device 100 as a fuel cell, the support 2b has, for example, a slightly curved shape, in particular, a domed shape, with a radius of curvature for example at least 140 mm and at most 180 mm for a support 2b with a 40 mm active area diameter. The domed shape allows the transport of liquid water to be improved because it transfers the domed shape to the first electrode 1, so that it causes the shape of the first face 11 and the second face 12, as well as the shape of the first membrane 41, to be the second membrane 42, of the second electrode 81, of the third electrode 82, changes from flat to convex, which favors the transport of liquid water produced during operation as a fuel cell, and its preferential evacuation from the second electrode 81 and/or third electrode 82 outside.

Continuing with Figure 2, the electrochemical device 100 comprises a first electrolyte membrane 41, a second electrolyte membrane 42, a cover 3, a first gasket 61 and a second gasket 62.

The first electrolyte membrane 41 is a membrane for circulation of protons and/or anions between the first electrode 1 and the second electrode 81. A first membrane 41 for circulation of protons makes it possible to generate an acid electrolytic medium in the first membrane 41. A first membrane 41 for circulation of anions allows generating a basic electrolytic medium in the first membrane 41.

The second electrolyte membrane 42 is a membrane for circulation of protons and/or anions between the first electrode 1 and the third electrode 82. A second membrane 42 for circulation of protons makes it possible to generate an acid electrolytic medium in the second membrane 42. A second membrane 42 for circulation of anions allows generating a basic electrolytic medium in the second membrane 42.

The cover 3 is made of a relatively rigid material that withstands contact with water and hydrogen at a temperature of up to 100 °C, such as, for example, aluminum, titanium and/or a thermoplastic. The cover 3 is shaped like a ring but, in other embodiments not illustrated, it has a shape other than the shape of a ring. The cover 3 comprises a first conduit 31. The first conduit 31 fluidically connects the compartment where the first electrode 1 is housed with the exterior of the cover 3. The first conduit 31 is configured, for example, to allow the entry of a gas into the compartment where the first electrode 1 is located. The cover 3 comprises a second conduit 32. The second conduit 32 fluidically connects the compartment where the first electrode 1 is housed with the exterior of the cover 3. The second conduit 32 is configured, for example , to allow gas to escape from the compartment. In this way, the electrochemical device 100 may comprise a conduit for the entry of gas into the compartment and a different conduit for the exit of gas from the compartment. The first conduit 31 and the second conduit 32 are, for example, conduits for the passage of hydrogen. The flow of hydrogen through the first conduit 31 can be regulated with a valve installed in the first conduit 31. The flow of hydrogen through the second conduit 32 can be regulated with a valve installed in the second conduit 32.

The first joint 61 makes it possible to form a watertight connection of the first conductive projection 21 with the first electrolyte membrane 41. The second gasket 62 makes it possible to form a watertight connection of the first conductive projection 21 with the cover 3. In this way, the first gasket 61 and the second gasket 62 maintain the tightness allowing the first conductive projection 21 to exit the electrochemical device, being the first conductive projection 21 between the first joint 61 and the second joint 62.

As can be seen from Figure 3, the first electrode 1 is in a compartment, for example, a sealed compartment. The tightness of the compartment allows hydrogen leaks from the compartment to be minimized. The compartment is delimited by an inner wall of the cover 3, by the first electrolyte membrane 41 and by the second electrolyte membrane 42. The first electrolyte membrane 41 is in contact with the face 11 of the first electrode 1 to reduce a resistance to the passage of protons and/or ions between the first electrode 1 and the first membrane 41. The second electrolyte membrane 42 is in contact with the face 12 of the first electrode 1 to reduce resistance to the passage of protons and/or ions between the first electrode 1 and the second membrane 42.

In some embodiments (not illustrated), the electrochemical device 100 comprises at least one gasket between the second membrane 42 and the cover 3, the gasket being configured to improve the tightness of the joint between the second membrane 42 and the cover 3.

Continuing with Figures 1, 2 and 6, the electrochemical device 100 comprises a second gas diffusion electrode 81, a third gas diffusion electrode 82, a second current collector 91 and a third current collector 92.

The second electrode 81 is an oxygen diffusion electrode. The second electrode 81 is an electrode suitable for:

• generate electrical energy from an electrochemical reaction with oxygen, such as oxygen from outside air, simultaneous with the hydrogen reaction at the first electrode 1 or

• generate oxygen through an electrochemical reaction caused by electrolysis of water by applying an electrical potential difference between the first current collector 2 and the second current collector 91.

A second electrode 81 suitable for generating electrical energy from a chemical reaction is, for example, a porous carbon cloth or carbon paper electrode coated with a catalyst. The catalyst is, for example, a catalyst for reducing oxygen, such as platinum or, more particularly, platinum nanoparticles. An example of a suitable concentration of platinum for reducing oxygen is a concentration of at least 0.05 mg of platinum per square centimeter of projected surface of the second electrode 81 and at most 0.3 mg of platinum per square centimeter of projected surface of the second electrode 81. The electrochemical device 100 may comprise a component to facilitate the capture and elimination of liquid water product of the chemical reaction. For example, the electrochemical device 100 may comprise a hydrophilic layer in contact with the second current collector 91 to allow ambient air to enter the second electrode 81 and to capture produced water. The hydrophilic layer is, for example, blotting paper. The component for capturing a chemical reaction product is in contact with the second current collector 91, so that a first surface of the second current collector 91 is in contact with the second electrode 81 and a second surface of the second current collector 91 is in contact with the second current collector 91. current is in contact with the component to capture the product, the second surface of the second current collector 91 being opposite the first surface of the second current collector 91. The capture and elimination of the water product is favored by hydrophilic columns 722, 721 of the external plates illustrated in Fig. 7.

A second electrode 81 suitable for generating oxygen simultaneously with the generation of hydrogen in the first electrode 1 by the electrolysis reaction of water by applying an electrical potential difference between the first current collector 2 and the second current collector 91 is, for example, For example, a porous electrode made of an oxidation-resistant material, such as a metallic foam of nickel and/or titanium coated with a catalyst suitable for oxidizing water and resistant to the electrical potentials reached in use as an electrolyzer. The suitable catalyst for oxidizing water is, for example, a platinum-ruthenium alloy oxide, a platinum-iridium alloy oxide, a ruthenium oxide, an iridium oxide and/or a nickel oxide. An example of a suitable concentration of catalyst for oxidizing water is a concentration of at least 0.05 mg per square centimeter of surface of the second electrode 81 and at most 0.5 mg per square centimeter of surface of the second electrode 81.

The catalyst of the second electrode 81 may be a non-reversible catalyst to accelerate:

• the generation of oxygen through a chemical reaction caused by electrolysis by applying an electrical potential difference between the first current collector 2 and the second current collector 91 or

• the generation of electrical energy from a chemical reaction of gases coming from the first electrode 1 and the second electrode 81.

The third electrode 82 is an oxygen diffusion electrode. The third electrode 82 is an electrode suitable for:

• generate electrical energy from a chemical reaction of gases coming from the first electrode 1 and the third electrode 82 or

• generate oxygen through a chemical reaction caused by electrolysis by applying an electrical potential difference between the first current collector 2 and the third current collector 92.

An advantage of using a non-reversible catalyst is its lower cost and greater efficiency and durability compared to reversible catalysts.

A third electrode 82 suitable for generating electrical energy from a chemical reaction is, for example, a porous carbon cloth or carbon paper electrode coated with a catalyst. The catalyst is, for example, a catalyst for reducing oxygen, such as platinum or, more particularly, platinum nanoparticles. An example of a suitable concentration of platinum for reducing oxygen is a concentration of at least 0.05 mg of platinum per square centimeter of projected surface of the third electrode 82 and at most 0.3 mg of platinum per square centimeter of projected surface of the third electrode 82. The electrochemical device 100 may comprise a component to facilitate the capture and elimination of water product of the chemical reaction. For example, the electrochemical device 100 may comprise a hydrophilic layer in contact with the third current collector 92 to allow a gas to enter the third electrode 82 and to capture the produced water. The hydrophilic layer is, for example, blotting paper. The component for capturing a chemical reaction product is in contact with the third current collector 92, such that a first surface of the third current collector 92 is in contact with the third electrode 82 and a second surface of the third current collector 92 is in contact with the third current collector 92. current is in contact with the component to capture the product, the second surface of the third current collector 92 being opposite to the first surface of the third current collector 92. The capture and elimination of the water product is favored by the hydrophilic columns 711,721 of the external plates illustrated in Fig. 7.

A third electrode 82 suitable for generating oxygen simultaneously with the generation of hydrogen in the first electrode 1 by the electrolysis reaction of water by applying an electrical potential difference between the first current collector 2 and the third current collector 92 is, for example, For example, an electrode that is porous and made of a material resistant to oxidation, such as a metal foam of nickel and/or titanium coated with a catalyst suitable for oxidizing water and resistant to the electrical potentials reached in use as an electrolyzer. The suitable catalyst for oxidizing water is, for example, a platinum-ruthenium alloy oxide, a platinum-iridium alloy oxide, a ruthenium oxide, an iridium oxide and/or a nickel oxide.

The third electrode catalyst 82 may be a non-reversible catalyst to accelerate:

• the generation of oxygen through a chemical reaction caused by electrolysis by applying an electrical potential difference between the first current collector 2 and the third current collector 92 or

• the generation of electrical energy from a chemical reaction of gases coming from the first electrode 1 and the third electrode 82.

Continuing with Figures 2 and 6, the second current collector 91 comprises a third electrically conductive grid 911. The third grid 911 is in contact with the second electrode 81. The third grid 911 is made of an electrically conductive material such as nickel. To decrease the electrical resistance of the contact between the third grid 911 and the second electrode 81, the third grid 911 may have a coating of a high electrical conductivity material on the face of the third grid 911 in contact with the second electrode 81. A An example of a material with high electrical conductivity is gold. The second current collector 91 comprises a second conductive projection 912. The second conductive projection 912 allows the second current collector 91 to be connected to an electrical circuit external to the electrochemical device 100.

Continuing with Figures 2 and 6, the third current collector 92 comprises a fourth electrically conductive grid 921. The fourth grid 921 is in contact with the third electrode 82. The fourth grid 921 is made of an electrically conductive material such as nickel. To decrease the electrical resistance of the contact between the fourth grid 921 and the third electrode 82, the fourth grid 921 may have a coating of a high electrical conductivity material on the face of the fourth grid 921 in contact with the third electrode 82. A An example of a material with high electrical conductivity is gold. The third current collector 92 comprises a third conductive projection 922. The third conductive projection 922 allows the third current collector 92 to be connected to an electrical circuit external to the electrochemical device 100.

To improve the efficiency of the electrochemical device 100, the electrical resistance of the electrochemical device can be minimized. Specifically, the resistance offered by components of the electrochemical device to the passage of ions and electrons can be minimized. This resistance is minimized, for example, by improving: the contact between the first electrode 1 and the first current collector 2, the contact between the first electrode 1 and the first electrolyte membrane 41, the contact between the first electrode 1 and the second electrolyte membrane 42, the contact between the second electrode 81 and the first electrolyte membrane 41, the contact between the third electrode 82 and the second electrolyte membrane 42, the contact between the second electrode 81 and the second current collector 91, the contact between the third electrode 82 and the third current collector 92.

To improve said contacts and/or the tightness of the compartment where the first electrode 1 is located, the electrochemical device 100 comprises, for example, clamping and compression elements 101. As illustrated in Figure 1 and Figure 7, the fastening and compression elements comprise, for example, a first plate 71, a second plate 72, screws 52 and nuts 51, 53. The first plate 71 it comprises first columns 711. The second plate 72 comprises second columns 721. The first plate 71 is made of, for example, aluminum, titanium, a porous metal and/or a rigid plastic. The second plate 72 is made of, for example, aluminum, titanium, a porous metal and/or a rigid plastic.

As can be seen from Figure 2, the first columns 711 are in contact with the third grid 911. The second columns 721 are in contact with the fourth grid 921.

The screws 52 pass through through holes of the components of the electrochemical device 100, so that they hold the components, in addition to allowing the tight closure of an intermediate portion 102 where the first electrode 1 and the hydrogen are housed, and allowing the adjustment of the contact pressure between the electrical components of the device. By actuating the nuts 51, the contact pressure between the components of the electrochemical device 100 is regulated. For example, by tightening the nuts 51, the contact pressure of the components is increased. By tightening the nuts 51, the pressure between the first columns 711 and the third grid 911 is increased, and the pressure between the second columns 721 and the fourth grid 921 is increased. In this way, the contact between the components of the electrochemical device is regulated. 100. Adequate compression is exerted by applying a tightening torque between 0.1 and 1 N-m to eight M3 steel nuts on each plate.

Actuating the nuts 53 makes it possible to regulate the tightness of the electrochemical device. For example, tightening the nuts 53 allows the tightness of the electrochemical device 100 to be increased. In this way, the entry and/or exit of hydrogen to the first electrode compartment is through conduits 31 and 32. Conduits 31 and 32 must have opening and closing valves.

To maximize the efficiency of the electrochemical device 100, the clamping and compression elements are configured to allow free access of reagents such as air and water from the outside of the device to a second 81 and a third electrode 82.

To electrically isolate the first plate 71 and the second plate 72 with respect to the electrodes of the electrochemical device 100, a first insulating plate 73 can be interposed between the first plate 71 and the second current collector 91 and a second insulating plate can be interposed 74 between the second plate 72 and the third current collector 92. Another form of electrical insulation between plates 71 and 72 is to make them from a non-conductive material, such as plastic. This insulation between plates 71 and 72 is necessary when the electrochemical device functions as a fuel cell and as an electrolyzer. In this case, a second electrode 81 and a third electrode 82 have to operate at different electrical potentials, since one functions as a fuel cell cathode (V = 0.4 to 0.9 V vs. NHE) and the other as an anode. of electrolyzer (V = 1.25 to 2.00 V vs. NHE).

The electrochemical device 100 is removable and mountable, since it can be disassembled by separating the nuts 51, 53 with respect to the screws 52 and can be reassembled by coupling the nuts 51, 53 to the screws 52.

In other embodiments (not illustrated), the components of the electrochemical device 100 are joined by adhesives such as glue, heat seal, and/or plastic heat sealing instead of by clamping and compression elements. In some embodiments (not illustrated), the adhesively bonded components are not reversibly separable. Non-reversibly detachable electrochemical device embodiments allow for a lighter electrochemical device compared to embodiments in which the electrochemical device is reversibly detachable, that is, configured to be mountable after disassembly, because the clamping and compression elements of Fig .7 can be simplified to only exert compression.

As illustrated in Figures 8, 9 and 10, the electrochemical device 100 can be configured to function as a fuel cell, as an electrolyzer, or as a fuel cell and electrolyzer simultaneously.

Figure 8 illustrates an electrochemical device 100 in which the second electrode 81 and the third electrode 82 are in contact with air. The electrochemical device 100 of Figure 8 functions as two fuel cells, a first fuel cell comprising the first electrode 1 and the second electrode 81 and a second fuel cell comprising the first electrode 1 and the third electrode 82. The Operation of the second electrode 81 and the third electrode 82 as a fuel cell to generate electricity requires feeding the compartment where the first electrode 1 is with hydrogen at a small overpressure of, for example, at least 0.3 bar and at most 1.0 bar above atmospheric pressure. The first conductive protrusion 21, the second conductive protrusion 912 and the third conductive protrusion 922 can be connected to an electrical load or an application through a DC-DC converter, that is, a direct current to direct current converter.

Figure 11 shows a polarization (electrochemical cell voltage vs. electrochemical cell current) and power (electrochemical cell electrical power vs. electrochemical cell current) curve of the operation of the electrochemical device 100 of Figure 8. This electrochemical device comprises a first electrode 1, a second electrode 81 and a third electrode 82 made of carbon cloth and catalyzed with platinum, specifically, with a concentration of 0.30 mg of platinum for each square centimeter of electrode surface.

Figure 9 illustrates an electrochemical device 100 in which the second electrode 81 and the third electrode 82 are in contact with water. The electrochemical device 100 of Figure 9 functions as two electrolyzers, a first electrolyzer comprising the first electrode 1 and the second electrode 81 and a second electrolyzer comprising the first electrode 1 and the third electrode 82. If the second electrode 81 and the third electrode 82 are immersed in water, as shown in Figure 9, the clamping and pressure structure is electrically isolated from the second electrode 81 and the third electrode 82 by, for example, use of suitable insulating components between the clamping screws and the plates. This electrical isolation is not necessary in this functionality but its advantage is that it allows each electrode to be independently monitored and controlled. The first conductive protrusion 21, the second conductive protrusion 912 and the third conductive protrusion 922 are connected to an electricity generator, such as a solar panel, a wind turbine, or any other source of electricity, external to the electrochemical device 100 to provide electrical energy with the appropriate voltage and current characteristics for the conversion reaction of water into hydrogen and oxygen. The hydrogen generated can be stored in the compartment itself where the first electrode 1 is located if the amount of hydrogen stored adjusts to the maximum pressure requirements that the compartment can withstand, for example, if the pressure of the compartment is not raised above 1 bar above atmospheric pressure. For larger amounts of stored energy, the interior of the compartment can be connected to a container for hydrogen, for example, via the second conduit 32.

Figures 12 and 13 illustrate the operation of the electrochemical device 100 of Figure 9. Figure 12 illustrates a first time evolution of current 121 applied to the electrolyzer to obtain hydrogen in the first electrode 1 and a second time evolution of current 122 generated with the hydrogen obtained and stored in an interior compartment of an intermediate portion 102. Figure 13 illustrates a first temporal evolution of electrical power 131 applied to the electrolyzer to obtain hydrogen and a second temporal evolution of electrical power 132 generated with the hydrogen obtained and stored.

The same electrochemical device may be configured to function as a fuel cell and an electrolyzer simultaneously, for example, if the second electrode 81 and the third electrode 82 have a suitable configuration as described above. In this functionality, the second electrode 81 is electrically isolated from the third electrode 82 to be at a different electrical potential. This isolation can be done in the manner indicated above. Operation as a simultaneous battery-electrolyzer can be achieved by partial immersion of the electrochemical device 100, as shown in Figure 10, submerging the third oxygen electrode 82 in water for electrolysis within the water, and leaving the second electrode 81 in contact. with air.

Figures 14 and 15 illustrate the operation of the electrochemical device 100 of Figure 10. The electrochemical device 100 of Figure 10 comprises a second carbon and platinum electrode 81 comprising a concentration of 0.30 mg of platinum per square centimeter of surface of the second electrode 81, and the third electrode 82 is formed by a nickel grid. This third electrode 82 is not optimal for the electrolytic function but serves to show the operation of the electrochemical device 100 of Figure 10. The fuel cell has been left polarized at 0.3 V so that it immediately consumes the hydrogen produced due to of the third electrode 82. The production and consumption of hydrogen are carried out simultaneously in a first electrode 1. In Figure 14 it is observed that the current produced 141 in the fuel cell is of the same magnitude as the current used 142 in the hydrogen generation which reflects a faradaic efficiency of 100%, that is, all the hydrogen produced in a first electrode 1 is immediately consumed in a first electrode 1. This is possible thanks to the reversibility of the hydrogen reaction H2^ 2H+ 2e- and to the design of a first electrode 1. Figure 15 shows the power consumed 151 in the electrolysis and the power generated 152 by the fuel cell. The energy efficiency of the process is 10% in this case. Higher efficiencies can be achieved by optimizing the electrolysis catalyst.

While the figures illustrate an electrochemical device with disc and ring shaped components, in other embodiments (not illustrated) said components of the electrochemical device have a shape other than the disc and ring shape, for example, parallelepiped shaped. Circular shapes such as disc shapes or ring shapes improve tightness and homogeneity compared to other shapes.

In this text, the term “comprehends” and its variants (such as “understanding”, etc.) should not be understood in an exclusive way, that is, they do not exclude the possibility that what is described includes other elements, steps, etc.

On the other hand, the invention is not limited to the specific embodiments that have been described but also encompasses, for example, the variants that can be carried out by the average person skilled in the art (for example, regarding the choice of materials, dimensions , components, configuration, etc.), within what is clear from the claims.

Claims (22)

1. Electrochemical device (100) for generating hydrogen and/or electric current, the electrochemical device comprising a first gas diffusion electrode (1), a second gas diffusion electrode (81) and a third diffusion electrode (82). Of gas; the first electrode (1) being for hydrogen diffusion; the second electrode (81) and the third electrode (82) being for oxygen diffusion; the first electrode (1) being in a compartment; the electrochemical device being characterized in that it comprises a first current collector (2), a second current collector (91) and a third current collector (92); the compartment being laterally delimited by a first electrolyte membrane (41) and by a second electrolyte membrane (42), where the first membrane (41) and/or the second membrane (42) are made of polymer electrolyte; the first electrode (1) being between the first electrolyte membrane (41) and the second electrolyte membrane (42), the first electrode (1) being in contact with the first electrolyte membrane (41) and with the second membrane ( 42) of electrolyte and the first electrode (1) being in contact with the first current collector (2); the second electrode (81) being between the first electrolyte membrane (41) and the second current collector (91); the third electrode (82) being between the second electrolyte membrane (42) and the third current collector (92); the second electrode (81) being in contact with the first electrolyte membrane (41) and with the second current collector (91); the third electrode (82) being in contact with the second electrolyte membrane (42) and with the third current collector (92). 2. The electrochemical device (100) of claim 1, the second electrode (81) and/or the third electrode (82) comprising a catalyst for oxidizing water; wherein the first electrode (1) preferably comprises a catalyst for reducing water or protons. 3. The electrochemical device (100) of claim 1, the second electrode (81) comprising a catalyst for oxidizing water and the third electrode (82) comprising a catalyst for reducing oxygen; wherein the first electrode (1) preferably comprises a catalyst for oxidizing hydrogen and for reducing water. 4. The electrochemical device (100) of claim 1, the second electrode (81) and/or the third electrode (82) comprising a catalyst for reducing oxygen; wherein the first electrode (1) preferably comprises a catalyst for oxidizing hydrogen. 5. The electrochemical device (100) of claim 2 or 3, the catalyst for oxidizing water comprising at least one of an oxide of a platinum and ruthenium alloy, an oxide of a platinum and iridium alloy, a ruthenium oxide, an iridium oxide and a nickel oxide; the second electrode (81) comprising a metal substrate, the substrate having pores. 6. The electrochemical device (100) of claim 3 or 4, wherein the catalyst for reducing oxygen comprises carbon coated with platinum nanoparticles with a concentration of at least 0.1 mg and at most 0.3 mg of platinum per each projected square centimeter of electrode, or wherein the catalyst for reducing oxygen comprises nickel and/or a porous carbon-based solid material doped with nitrogen and iron, the doped carbon-based porous solid material having the formula FeCxNy. 7. The electrochemical device (100) of claim 2 or 3, wherein the catalyst for reducing water or protons comprises particles of a microporous carbon coated with platinum nanoparticles with a concentration of at most 0.3 mg of platinum per projected square centimeter of electrode. 8. The electrochemical device (100) of any one of the preceding claims, the first electrode (1) comprising a first face (11) and a second face (12), the first face (11) being in contact with the first membrane (41) of electrolyte and the second face (12) being in contact with the second membrane (42) of electrolyte; the first current collector (2) comprising a first grid and a second grid, the first grid being electrically connected to the second grid, the first face (11) of the first electrode (1) being in contact with the first grid and the second face (12) of the first electrode (1) in contact with the second grid; The first grid and the second grid being for conduction of electric current, and connection to the outside through a conductive projection (21) that maintains the tightness of the compartment of the first electrode (1). 9. The electrochemical device (100) of any one of the preceding claims, the second current collector (91) comprising a third grid (911), the third grid (911) being in contact with the second electrode (81); the third grid (911) being for conduction of electric current. 10. The electrochemical device (100) of any one of the preceding claims, the third current collector (92) comprising a fourth grid (921), the fourth grid (921) being in contact with the third electrode (82); the fourth grid (921) being for conduction of electric current. 11. The electrochemical device (100) of any one of the preceding claims, the first electrode (1) being hydrophobic; the first electrode (1) being preferably superhydrophobic. 12. The electrochemical device (100) of any one of the preceding claims, the electrochemical device comprising a first gas conduit (31) and a second gas conduit (32); the first conduit (31) being fluidically connected to the compartment and the second conduit (32) being fluidically connected to the compartment, the first conduit (31) and the second conduit (32) having opening and closing valves for hydrogen. 13. The electrochemical device (100) of any one of the preceding claims, the electrochemical device comprising a first plate (71) with first columns (711) and a second plate (72) with second columns (721); the second current collector (91) being between the first plate (71) and the second electrode (81); the first columns (711) pressing the second current collector (91) against the second electrode (81); the third current collector (92) being between the second plate (72) and the third electrode (82); pressing the second columns (721) the third current collector (92) against the third electrode (82); wherein preferably the first columns (711) comprise a hydrophilic material and/or the second columns (721) comprise a hydrophilic material. 14. The electrochemical device (100) of claim 13, wherein the first plate (71), the second current collector (91), the second electrolyte membrane (42), the first electrolyte membrane (41), the third current collector (92) and the second plate (72) comprise through holes; the electrochemical device comprising screws (52) and nuts (51, 53) coupled to the screws (52); the through holes being crossed by the screws (52); the electrochemical device being configured to regulate the pressure between the columns and the second and third current collectors (91, 92) by operating the nuts (51), and to regulate the tightness of the compartment of a first electrode (1) by operating the nuts ( 53). 15. The electrochemical device (100) of any one of the preceding claims, the electrochemical device being removable and mountable; the electrochemical device comprising a disassembly configuration in which: - the second electrode (81) is separated from the second current collector (91), - the second electrode (81) is separated from the first electrolyte membrane (41), - the third electrode (82) is separated from the third current collector (92), and/or - the third electrode (82) is separated from the second electrolyte membrane (42). 16. The electrochemical device (100) of any one of the preceding claims and a photovoltaic panel, the photovoltaic panel being electrically connected to the projection (21) of the first current collector (2) and to a second conductive projection (912) of the second collector (91) of current and/or the photovoltaic panel being electrically connected to the first current collector and to a third conductive projection (922) of the third current collector. 17. The electrochemical device (100) of any one of claims 1 to 15 and a wind turbine, the wind turbine being electrically connected to the projection (21) of the first current collector (2) and to a second conductive projection (912) of the second collector (91) of current and/or the wind turbine being electrically connected to the projection (21) of the first current collector and to a third conductive projection (922) of the third current collector. 18. Use of the electrochemical device (100) of any one of claims 1 to 15 to generate hydrogen and electricity; the second electrode (81) being in contact with water, the third electrode (82) being in contact with oxygen and the first electrode being in contact with hydrogen; the projection (21) of the first current collector (22) and a second conductive projection (912) of the second current collector (91) being connected to the negative (reducing) and positive (oxidizing) poles, respectively, of a generator. direct current (DC) electricity; the projection (21) of the first current collector (22) and a third conductive projection (922) of the third current collector (92) being connected to the negative and positive poles, respectively, of a load or application supplied with direct current ( D.C.); The use comprising passing a current between the first current collector (2) and the second current collector (91) so that the non-spontaneous electrochemical reaction of water dissociation H2O → H2+ 0.5O2 takes place and hydrogen is generated in the compartment of a first electrode (1); and/or comprising the use of the spontaneous electrochemical reaction of hydrogen and oxygen to generate water H2+ 0.5O2 → H2O between the third electrode (82) and the first electrode (1), the electrochemical reaction generating an electric current between the first collector ( 2) current and the third current collector (92). 19. Use of the electrochemical device (100) of any one of claims 1 to 15 to generate hydrogen, the second electrode (81) and the third electrode (82) being in contact with water, the first electrode (1) being in contact with protons and/or water; connecting an external direct current (DC) electricity generator with the negative pole (reducing potential) to the protrusion (21) of the first current collector (2) and with the positive pole (oxidizing potential) to the second and third collectors (91) and (92) through their respective conductive projections (912) and (922); the use comprising the electrochemical reaction H2O → H2+ 0.5O2 between the second electrode and the first electrode and the same electrochemical reaction H2O → H2+ 0.5O2between the third electrode and the first electrode, generating the electrochemical reaction hydrogen in the compartment. 20. Use of the electrochemical device (100) of any one of claims 1 to 15 to generate electricity; the second electrode (81) and the third electrode (82) being in contact with oxygen, and the first electrode being in contact with hydrogen; the use comprising the electrochemical reaction H2+ 0.5O2 → H2O between the second electrode (81) and the first electrode (1) and the same electrochemical reaction H2+ 0.5O2 → H2O between the third electrode (82) and the first electrode (1 ), the electrochemical reaction generating an electric current that will circulate through an external circuit between the projection (21) of the first current collector (2) and the projections (912) and (922) of the second and third current collectors (91) and (92). 21. Use according to claim 18, a photovoltaic panel and/or a wind turbine being electrically connected to the projection (21) of the first current collector (2) (negative-reducing pole) and to the second conductive projection (912) of the second collector ( 91) of current (positive-oxidizing pole) or electrically connected(s) to the projection (21) of the first current collector (2) (negative-reducing pole) and to the third conductive projection (922) of the third collector (92) of current (positive-oxidant pole). 22. Use according to claim 19, a photovoltaic panel and/or a wind turbine being electrically connected (s) to the projection (21) of the first current collector (2) (negative-reducing pole) and to a second conductive projection (912) of the second current collector (91) (positive-oxidizing pole) and electrically connected(s) to the projection (21) of the first current collector (2) (negative-reducing pole) and to a third conductive projection (922) of the third collector ( 92) current (positive-oxidizing pole).