Separator element arrangement for electrochemical cells containing nanostructures - Patents.com

Abstract

A separator element arrangement (300) for an electrochemical cell is provided. The separator element arrangement includes a separator element (310) and a diffusion layer (320) disposed adjacent to the separator element (310). The separator element includes a plurality of elongated nanostructures (311). At least some of the elongated nanostructures are arranged to extend into the diffusion layer, thereby coupling the separator element (310) to the diffusion layer (320).

Description

[Technical field]

[0001] The present disclosure relates to separator elements and separator element arrangements suitable for electrochemical cells, such as fuel cells and electrolyzers. [Background technology]

[0002] Electrochemical cells, such as batteries, fuel cells, and electrolyzers, are becoming widely used in modern energy systems. The production of hydrogen gas by electrolysis of water is a promising technology to replace the production of hydrogen gas from fossil fuels, and also as a means to convert excess electrical energy from intermittent energy sources, such as solar and wind power, into chemical energy for storage. At the same time, fuel cells are an attractive technology for converting chemical energy to electrical energy, in part due to their high efficiency compared to, for example, internal combustion engines, and in part due to the ease of using environmentally friendly fuels, such as sustainably produced hydrogen gas.

[0003] However, existing electrochemical cells suffer from high contact resistance between different cell components, which reduces efficiency, a problem that can be exacerbated by the formation of non-conductive surface layers on some components due to the cell's chemical environment.

[0004] US Pat. No. 5,399,433 discloses a component for an electrochemical cell with reduced contact resistance.

[0005] There remains a need for electrochemical cells having components that exhibit lower contact resistance. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2019 / 186047 Summary of the Invention [Problem to be solved by the invention]

[0007] It is an object of the present disclosure to provide, inter alia, an improved separator element arrangement for an electrochemical cell that provides reduced contact resistance between the separator element and the diffusion layer. [Means for solving the problem]

[0008] This object is achieved, at least in part, by a separator element apparatus for an electrochemical cell, the separator element apparatus including a separator element and a diffusion layer disposed adjacent to the separator element, the separator element including a plurality of elongated nanostructures, at least some of the elongated nanostructures disposed to extend into the diffusion layer, thereby coupling the separator element to the diffusion layer. Effect of the Invention

[0009] By extending at least some of the elongated nanostructures into the diffusion layer, it is meant that some of the nanostructures go beyond the surface of the diffusion layer facing the separator element, for example by extending into holes or grooves provided on the surface of the diffusion layer. The elongated nanostructures are thus arranged in direct contact with the diffusion layer, thereby improving the mechanical and electrical contact between the diffusion layer and the separator element. This is particularly true when the elongated nanostructures comprise an electrically conductive material, i.e. a material having an electrical conductivity similar to that of a metal or a semiconductor.

[0010] In other words, the separator element apparatus includes a separator element and a diffusion layer disposed adjacent to the separator element, the separator element apparatus also includes a plurality of elongated nanostructures attached to a surface of the separator element facing the diffusion layer, with at least some of the elongated nanostructures positioned to extend into the diffusion layer, thereby coupling the separator element to the diffusion layer.

[0011] The separator element may be a planar element or separator plate. Similarly, the diffusion layer may be a planar element or structure. This facilitates assembly of the separator element device and incorporation of the separator element device into an electrochemical cell.

[0012] The plurality of elongated nanostructures may include elongated carbon nanostructures. Carbon nanostructures are advantageous because they exhibit good electrical conductivity and sufficient chemical stability for use in many electrochemical cells. In particular, the elongated carbon nanostructures may include any of carbon nanofibers, carbon nanowires, and carbon nanotubes. The properties of carbon nanofibers, carbon nanowires, and carbon nanotubes, such as density and shape, can be easily adjusted by modifying the conditions under which the nanofibers, nanowires, and nanotubes are manufactured. Carbon nanofibers and carbon nanowires are also mechanically stiff, making it easier to maintain their orientation relative to the separator element during assembly of the separator element device.

[0013] The plurality of elongated nanostructures may comprise elongated metallic nanostructures, which also exhibit high electrical conductivity and good mechanical stability and rigidity.

[0014] According to an embodiment, at least some of the elongated nanostructures may be oriented parallel to one another and extend along a direction perpendicular to the extension plane of the separator element. This means that these elongated nanostructures have a similar orientation and extend generally perpendicularly from the extension plane of the separator element, forming a forest of nanostructures. The approximately uniform orientation of the elongated nanostructures facilitates the assembly of the separator element device. The orientation of the nanostructures generally perpendicular to the extension plane of the separator element ensures that the nanostructures do indeed extend into the diffusion layer, and makes it easier to control how far the nanostructures extend into the diffusion layer.

[0015] According to another embodiment, at least some of the elongated nanostructures may be oriented at an angle of 10 to 80 degrees relative to the extension plane of the separator element.

[0016] The intended length of the elongated nanostructures may depend, inter alia, on the properties of the diffusion layer. In particular, when the diffusion layer comprises a porous material, the intended length of the elongated nanostructures may depend on the structure of said porous material, and according to an embodiment, the length of at least one of the elongated nanostructures measured along an axis extending perpendicular to the extension plane of the separator element may be between 10 and 20 micrometers. According to another embodiment, the length of the maximum dimension of at least one of the elongated nanostructures may be between 10 and 20 micrometers.

[0017] The separator element may include a flow field device disposed on a surface of the separator element facing the diffusion layer, the flow field device including a plurality of flow channels separated by a plurality of flow channel supports. The flow channels may be arranged to promote uniform distribution of gas and / or liquid throughout the flow field device. Uniform distribution of gas and / or liquid throughout the flow field device is advantageous because it results in uniform distribution of reactants within the electrochemical cell, leading to more efficient utilization of the overall area of ​​the cell.

[0018] When the separator element comprises a flow field device, the plurality of elongated nanostructures may be bonded to a surface of at least one of the flow field device flow field supports, said surface facing the diffusion layer. The flow field support forms a raised ridge on the separator element surface, which means that the flow field support is in closer contact with the diffusion layer. It is therefore advantageous that the nanostructures are located only on the flow field support, and preferably only on the top of the flow field support.

[0019] The separator element may include a protective coating disposed thereon to increase corrosion resistance, the protective coating can shield the material of the separator element from the chemical environment of the electrochemical cell to prevent degradation.

[0020] According to an embodiment, the diffusion layer includes a porous carbon material. The porous carbon material may include a porous carbon material, and the plurality of carbon fibers may extend generally parallel to the extension plane of the separator element and / or generally perpendicular to the plurality of elongated nanostructures. Carbon materials are suitable for use in the diffusion layer based on their electrical conductivity and chemical stability. Porous carbon materials are also advantageous because they may enable efficient transport of reactants and products through the electrochemical cell.

[0021] Objects are also achieved, at least in part, by a method of manufacturing a separator element device including a separator element and a diffusion layer disposed adjacent to the separator element. The method includes generating a plurality of elongated nanostructures, the elongated nanostructures being bonded to a surface of the separator element. The method also includes disposing the diffusion layer adjacent to the separator element such that the elongated nanostructures extend into the diffusion layer, thereby bonding the separator element to the diffusion layer.

[0022] By extending into the diffusion layer, the elongated nanostructures are placed in direct contact with the diffusion layer, thereby improving the mechanical and electrical contact between the diffusion layer and the separator element, particularly when the elongated nanostructures comprise a conductive material, i.e., a material that has an electrical conductivity similar to that of a metal or semiconductor.

[0023] Producing the plurality of elongated nanostructures may include growing the elongated nanostructures on a substrate. Growing the elongated nanostructures on a substrate may be advantageous because it allows tailoring of the properties and shape of the nanostructures by tailoring the conditions under which the nanostructures are grown, for example to improve mechanical and electrical contact between the nanostructures and the diffusion layer. For example, the thickness of the elongated nanostructures may be tailored to improve structural stability.

[0024] It is advantageous if the substrate includes separator elements arranged such that the nanostructures are grown on the separator elements, as this establishes chemical bonds between the nanostructures and the surface and contributes to good electrical contact and low contact resistance between the elongated nanostructures and the separator elements.

[0025] Growing the elongated nanostructures on the substrate may include depositing a growth catalyst layer on a surface of the substrate and growing the elongated nanostructures on the growth catalyst layer. The growth catalyst layer promotes the growth of the elongated nanostructures. By modifying the properties of the growth catalyst layer, the properties of the grown elongated nanostructures can be tailored to improve the functionality of the separator element device.

[0026] Depositing the growth catalyst layer may include depositing a uniform growth catalyst layer and introducing a pattern onto the deposited uniform growth catalyst layer. An advantage of introducing a pattern onto the deposited uniform growth catalyst layer is that it allows for control of the number of nanostructures per surface area of ​​the substrate. The number of nanostructures per surface area may be adapted to the structure of the diffusion layer, for example, to improve electrical and mechanical contact between the nanostructures and the diffusion layer.

[0027] The method may include depositing a conductive layer on the surface of the substrate. Depositing a conductive layer on the surface of the substrate may advantageously have the effect of electrically grounding the substrate. Electrical grounding of the substrate may be advantageous for certain nanostructure growth methods. When a conductive layer is deposited on the surface of the substrate and a growth catalyst layer is deposited on top of the conductive layer, the conductive layer may also prevent cross-diffusion of atoms and / or molecules between the catalyst layer and the substrate.

[0028] The method may further include at least partially coating the separator element with a protective coating arranged to increase corrosion resistance, the protective coating may shield the material of the separator element from the chemical environment of the electrochemical cell to prevent degradation.

[0029] Also disclosed herein is a fuel cell including an ion exchange membrane, a first electrode catalyst layer, and a second electrode catalyst layer. The first and second electrode catalyst layers are disposed adjacent to the ion exchange membrane on either side of the ion exchange membrane. The fuel cell further includes a first separator element arrangement and a second separator element arrangement disposed adjacent to the first and second electrode catalyst layers, respectively, on the side of each electrode catalyst layer facing outward from the ion exchange membrane. Each separator element arrangement includes a separator element and a diffusion layer disposed adjacent to the separator element.

[0030] At least one of the separator element devices is a separator element device as described above, i.e., the separator element device includes a plurality of elongated nanostructures attached to a surface of a separator element, the surface being the surface facing the diffusion layer. At least some of the elongated nanostructures are arranged to extend into the diffusion layer, thereby bonding the separator element to the diffusion layer. This separator element device is associated with all of the advantages described above. When the separator element device is disposed in a fuel cell, there is an additional advantage of providing a fuel cell with lower contact resistance between the separator element of the separator element device and the diffusion layer, which improves fuel cell efficiency.

[0031] Additionally disclosed is a fuel cell stack comprising at least one fuel cell described herein.

[0032] Also disclosed is an electrolytic cell comprising an ion exchange membrane, a first electrode catalyst layer and a second electrode catalyst layer, the first and second electrode catalyst layers being disposed adjacent to the ion exchange membrane on either side of the ion exchange membrane. The electrolytic cell further comprises first and second separator element arrangements disposed adjacent to the first and second electrode catalyst layers, respectively, on the side of each electrode catalyst layer facing outwardly from the ion exchange membrane. Each separator element arrangement comprises a separator element and a diffusion layer disposed adjacent to the separator element.

[0033] At least one of the separator element devices is a separator element device as described herein, i.e., the separator element device includes a plurality of elongated nanostructures attached to a separator element, with at least some of the elongated nanostructures arranged to extend into the diffusion layer, thereby coupling the separator element to the diffusion layer. This separator element device is associated with all of the advantages discussed above. When the separator element device is placed in an electrolytic cell, it has the added advantage of providing an electrolytic cell with lower contact resistance between the separator element of the separator element device and the diffusion layer, thereby improving the efficiency of the electrolytic cell.

[0034] Also disclosed is an electrolytic cell stack comprising at least one electrolytic cell as described above.

[0035] Broadly speaking, all terms used in the claims should be interpreted according to their ordinary meaning in the art, unless expressly defined otherwise herein. Any reference to "a / an / the element, apparatus, component, means, step, etc." should be openly interpreted as meaning at least one instance of that element, apparatus, component, means, step, etc., unless expressly specified otherwise. The steps of any method disclosed herein need not be performed in the exact order disclosed, unless expressly specified otherwise. Further features and advantages of the present invention will become apparent upon consideration of the appended claims and the following description. As will be apparent to one skilled in the art, different features of the present invention may be combined to form different embodiments than those described below without departing from the scope of the present invention.

[0036] The present disclosure will now be described in detail with reference to the accompanying drawings. [Brief description of the drawings]

[0037] [Figure 1] FIG. 1 is a schematic diagram showing a fuel cell. [Diagram 2]FIG. 2 is a schematic diagram showing an electrolytic cell. [Diagram 3] FIG. 3 is a schematic diagram showing a separator element apparatus. [Figure 4] 4A, B and C are schematic diagrams showing the flow field device. [Diagram 5] FIG. 5 is a diagram showing a fuel cell stack. [Figure 6] FIG. 6 is a flow chart illustrating the method. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0038] Aspects of the present disclosure are described in detail below with reference to the accompanying drawings. However, the various devices and methods disclosed herein may be embodied in many different forms and should not be construed as being limited to the aspects shown herein. Like reference numerals in the drawings refer to like elements throughout the drawings.

[0039] The terminology used herein is for the purpose of describing the disclosed embodiments only and is not intended to be limiting of the present invention. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly dictates otherwise.

[0040] The following description focuses on two types of electrochemical cells: fuel cells and electrolyzers. Specifically, the following description discusses fuel cells and electrolyzers, respectively, that include a proton exchange membrane and that use hydrogen gas as fuel or produce hydrogen gas from water. However, as will be apparent to one of ordinary skill in the art, the devices and methods described herein can also be used with other types of electrochemical cells. The present disclosure can also be applied to other types of fuel cells, such as fuel cells that use methanol as fuel, and other types of electrolyzers. Specifically, the present disclosure can be applied to fuel cells and electrolyzers in which another type of solid electrolyte, such as an anion exchange membrane, is used instead of a proton exchange membrane.

[0041] In a fuel cell, chemical energy from a fuel is converted into electrical energy through reduction and oxidation reactions. A fuel cell contains two electrodes and an electrolyte that allows ions to move between the electrodes. The electrodes are also electrically connected to an electrical load, where the generated electrical energy is used.

[0042] Fuel cell electrolytes must be good ionic conductors, i.e. capable of transporting ions, and at the same time poor electronic conductors, i.e. inhibiting the transport of electrons. Fuel cell electrolytes can be liquids, e.g. solutions of alkali salts or molten carbonate compounds, or solids, e.g. polymeric membranes or metal oxides. Examples of polymeric membrane materials are sulfonated tetrafluoroethylene, also known as Nafion, and polymers based on polysulfone or polyphenol oxide. Ionically conducting metal oxides can be, e.g., doped barium zirconate, doped barium cerate, doped lanthanum gallate, or stabilized zirconia. Different electrolytes may be suitable to conduct different types of ions. For example, membranes based on sulfonated tetrafluoroethylene, e.g. Nafion, can conduct hydrogen ions, i.e. protons, and are therefore known as proton exchange membranes or PEMs. Numerous metal oxides are suitable to conduct oxygen ions.

[0043] Fuel cells using ion exchange membranes, such as Nafion, are often called proton exchange membrane fuel cells or PEMFCs, because the membranes conduct protons. In a PEMFC, a hydrogen-containing fuel, such as hydrogen gas, is introduced at a first electrode, the anode, while an oxygen-containing gas is introduced at a second electrode, the cathode. At the anode, hydrogen is split into protons and electrons with the aid of an electrocatalyst. This is called the hydrogen oxidation reaction. The protons pass through the ion exchange membrane to reach the cathode, while the electrons pass through an electrical connection between the anode and the cathode, where the generated electrical energy can be utilized. At the cathode, the protons and electrons react with oxygen via an oxygen reduction reaction to form water. This reaction is aided by an electrocatalyst.

[0044] A catalyst is a material or compound that facilitates a chemical reaction, for example by reducing the amount of energy required to initiate the reaction. Electrocatalysts are catalysts used in electrochemical reactions, such as the hydrogen oxidation and oxygen reduction reactions, that take place in fuel cells. Fuel cell electrocatalysts often contain precious metals, such as platinum, ruthenium, or palladium.

[0045] For PEMFCs, and other fuel cells using solid ion conductors, the anode and cathode catalysts are often arranged as electrocatalyst layers on the opposing surfaces of the ion exchange membrane. For PEMFCs in particular, the electrocatalyst layer often comprises electrocatalyst material such as platinum in the form of nanoparticles, i.e. particles having diameters significantly less than 1 micrometer, mainly between 1 and 100 nm. The electrocatalyst layer also typically comprises a catalyst binder or catalyst support, which often comprises carbon nanomaterials, e.g. carbon nanoparticles or nanotubes, or carbon black. The electrocatalyst layer may comprise an ion-conducting polymer and a hydrophobic material, e.g. Teflon, arranged to facilitate the transport of hydrogen ions to the ion exchange membrane. According to an embodiment, the catalyst layer may be 5 to 50 nm thick. According to another embodiment, the thickness of the catalyst layer may depend on the type of catalyst used.

[0046] An ion exchange membrane having an anode electrode catalyst layer and a cathode electrode catalyst layer disposed on opposing surfaces thereof is sometimes called a membrane electrode assembly.

[0047] For a fuel cell to operate, ions and electrons must be able to migrate from the anode electrode catalyst through the ion exchange membrane and the electrical load, respectively, and reach the cathode electrode catalyst. In addition, reactant gases, such as hydrogen gas and oxygen gas, must be able to reach the electrode catalyst layers, while product water must be continuously removed from the cell. In most PEMFCs, this is accomplished by placing a porous diffusion layer comprising an electrically conductive material next to each electrode catalyst layer, and placing a separator element, also comprising an electrically conductive material, next to each diffusion layer. The combination of the porous diffusion layer and the separator element is referred to herein as the separator element device.

[0048] An electrically conductive material, element, or component is considered herein to be a material, element, or component that has a high electrical conductivity. High electrical conductivity is typically considered to be a material, element, or component that has a high electrical conductivity, typically a material such as a metallic or semiconducting material, or a material with a conductivity of 100 Sm -1 This refers to ultra-high conductivity.

[0049] FIG. 1 shows a fuel cell 100 including an ion exchange membrane 130, a first electrode catalyst layer 111 and a second electrode catalyst layer 121. The first electrode catalyst layer 111 and the second electrode catalyst layer 121 are arranged adjacent to the ion exchange membrane on either side of the ion exchange membrane. On the side of the electrode catalyst layers facing away from the ion exchange membrane 130, a first separator element arrangement 110 and a second separator element arrangement 120 are arranged adjacent to the first electrode catalyst layer and the second electrode catalyst layer, respectively. Each separator element arrangement includes a diffusion layer and a separator element. In the fuel cell, each separator element arrangement is arranged such that a diffusion layer is sandwiched between the respective electrode catalyst layer and a separator element contained in the separator element arrangement. The two separator element arrangements are electrically connected through a load 140.

[0050] The porous diffusion layer, sometimes referred to as a current collector or mass transport layer, is positioned to allow reactants and products, such as hydrogen gas, oxygen gas, and water, to be transported through the pores of the diffusion layer while still maintaining electrical contact between the electrocatalyst layer and the separator element. The porous diffusion layer often comprises a porous conductive material, such as metal foam, porous carbon, or carbon paper. The diffusion layer may also provide structural support to the electrocatalyst layers 111, 121 and the ion exchange membrane 130.

[0051] The separator element often comprises a metallic material, e.g. steel, and / or another electrically conductive material, e.g. a carbon composite. It is the component that is connected to the electrical load and separates the fuel cell from its surroundings. If the fuel cell forms part of a fuel cell stack, the separator element may form part of the cathode side of one fuel cell and part of the anode side of an adjacent fuel cell, in which case the separator element may be called a bipolar plate. Other possible terms are separator plate or flow plate.

[0052] For efficient fuel cell operation, it is important to minimize the electrical contact resistance between the elements of the fuel cell, i.e., the electrical resistance associated with the interface between, for example, a separator element and an adjacent diffusion layer, or between a diffusion layer and an adjacent electrode catalyst layer. However, high contact resistance between a separator element and an adjacent diffusion layer can result, for example, from poor physical contact between the two components. This problem can be exacerbated by the formation of non-conductive compounds, such as metal oxides, on the surface of the separator element.

[0053] Water electrolysers, on the other hand, use electrical energy to split water into oxygen and hydrogen gases. Electrolysers may generally include the same components as those described above for fuel cells. Specifically, electrolysers include an ion-conducting electrolyte and two electrodes, a cathode and an anode. The cathode and anode are electrically connected to a power source. Proton exchange membranes, such as Nafion, can be used as the electrolyte in electrolysers and fuel cells, as can the other polymer membranes and solid oxide ion conductors described above. Liquid electrolytes, including alkaline solutions, may also be used.

[0054] In an electrolyser containing a proton conducting electrolyte, e.g. PEM, water is introduced at the anode side where it is split into oxygen and hydrogen, known as the oxygen evolution reaction. The oxygen forms oxygen gas, while the hydrogen is subsequently split into protons that pass through an ion exchange membrane to reach the cathode, and electrons that travel to the cathode via a power source. At the cathode, the protons and electrons form hydrogen gas via the hydrogen evolution reaction.

[0055] The electrocatalysts in electrolysers may be different from those used in fuel cells. In electrolysers using a PEM electrolyte, the anode side electrocatalyst often contains iridium oxide, while the cathode side electrocatalyst generally contains platinum or other platinum group metals. In electrolysers using an anion exchange membrane AEM electrolyte, both electrocatalysts may instead contain materials such as nickel or cobalt.

[0056] In electrolytic cells containing solid electrolytes, such as PEMs and AEMs, the anode and cathode electrocatalysts are often disposed in electrocatalyst layers on opposite sides of the electrolyte membrane to form a membrane electrode assembly, as described above for fuel cells. One or both electrocatalysts may be in the form of nanoparticles. In addition to the electrocatalyst itself, the electrocatalyst layer may include a catalyst support, such as carbon black, carbon nanotubes, or metal foam. The electrocatalyst layer may include an ion-conducting polymer and a hydrophobic material, such as Teflon.

[0057] The requirements for ion transport through the electrolyte, mass transport of reactants and products to and from the electrocatalysts, and good electrical contact between elements within the cell are the same in electrolyzers as in fuel cells. Thus, electrolyzers often also include a porous diffusion layer disposed adjacent to each electrocatalyst layer, and a separator element disposed adjacent to each diffusion layer. The diffusion layers may comprise porous carbon materials, often including titanium, metal foams, or metal meshes. The separator plates may comprise, for example, metallic materials, such as steel or titanium, or conductive carbon composites.

[0058] FIG. 2 shows an electrolytic cell 200 including an ion exchange membrane 230, a first electrode catalyst layer 211 and a second electrode catalyst layer 221. The first and second electrode catalyst layers are disposed adjacent to the ion exchange membrane 230 on either side of the ion exchange membrane. A first separator element arrangement 210 and a second separator element arrangement 220 are disposed adjacent to the first and second electrode catalyst layers on the side of the electrode catalyst layers facing away from the ion exchange membrane 230. Each separator element arrangement includes a diffusion layer and a separator element. When disposed in the electrolytic cell, each separator element arrangement is arranged such that the diffusion layer is sandwiched between the separator element and the respective electrode catalyst layer. Both separator element arrangements are connected to a power source 240.

[0059] In both fuel cells and electrolyzers, contact resistance between components can be reduced if better mechanical contact between the components is established. Figure 3 shows a separator element arrangement 300 for an electrochemical cell with improved mechanical contact and reduced contact resistance between the separator element and the diffusion layer. The separator element arrangement 300 includes a separator element 310 and a diffusion layer 320 disposed adjacent the separator element 310. The separator element includes a plurality of elongated nanostructures 311, at least some of which are arranged to extend into the diffusion layer, thereby coupling the separator element 310 to the diffusion layer 320.

[0060] Nanostructures are structures with a size in at least one dimension significantly less than 1 micrometer, preferably between 1 and 100 nm. As used herein, elongated nanostructures are nanostructures in which at least one dimension, e.g., length, is significantly greater than another dimension, e.g., width or depth. As an example, consider a roughly cylindrical nanostructure characterized by a length and a diameter. A nanostructure is considered elongated if its length is significantly greater than its diameter, e.g., if its length is more than twice its diameter. Similar reasoning can be applied to nanostructures that are substantially conical, frustoconical, rectangular, or of any shape.

[0061] The elongated nanostructures 311 may be, for example, straight, spiral, branched, wavy, or tapered. Optionally, the elongated nanostructures may be classified as nanowires, nanohorns, nanotubes, nanowalls, crystalline nanostructures, or amorphous nanostructures.

[0062] Preferably, the elongated nanostructures 311 comprise a conductive material.

[0063] Broadly speaking, the elongated nanostructures 311 contained within the separator element 310 are attached to a surface of the separator element 310 facing the diffusion layer 320. The elongated nanostructures 311 may be attached to the surface of the separator element 310, for example, by chemical bonding, by adhesive, or by some other attachment means. According to an embodiment, the elongated nanostructures 311 may be grown on the surface of the separator element 310. In this case, the elongated nanostructures may have a strong chemical bond to the surface. Preferably, the elongated nanostructures should be attached to the surface in a manner that provides low contact resistance between the nanostructures and the surface.

[0064] At least some nanostructures in the plurality of elongated nanostructures 311 extending into the diffusion layer 320 may be taken to mean that at least some of the plurality of elongated nanostructures extend beyond the surface of the diffusion layer that faces the separator element 310. In Figure 3, this surface is indicated by dashed line 330. If the surface is not planar, for example if the surface is curved or uneven, then a nanostructure may be considered to extend into the diffusion layer if the nanostructure extends beyond the tangent to the surface at the point where the surface is closest to the nanostructure.

[0065] In other words, separator element apparatus 300 includes separator element 310 and diffusion layer 320 disposed adjacent separator element 310. Separator element apparatus 300 also includes a plurality of elongated nanostructures 311 disposed in attachment to a surface of separator element 310 facing diffusion layer 320. At least some of the elongated nanostructures are disposed to extend into the diffusion layer, thereby coupling separator element 310 to diffusion layer 320.

[0066] The diffusion layer 320 generally comprises a porous material, i.e. a material that contains a plurality of voids, holes, or pores. Some of the pores intersect the surface of the material, forming pits or grooves in said surface. In this case, elongated nanostructures contained within the separator element may extend into the diffusion layer by extending into such pits or grooves in the surface facing the separator element. This may also be seen as elongated nanostructures 311 being at least partially embedded in the diffusion layer.

[0067] As one example, the nanostructures may extend more than 50% of their length into the diffusion layer, and as another example, the nanostructures may extend more than 90% of their length into the diffusion layer.

[0068] Porous materials can be characterized by their void fraction, i.e., the ratio of the volume of voids or pores to the total volume of the material. The void fraction of the porous material contained within the diffusion layer 320 may be, for example, 0.3 or greater, or the void fraction may be greater than 0.5.

[0069] The elongated nanostructures form an intimate mechanical contact with the separator element and the diffusion layer. The intimate mechanical contact improves the electrical contact and reduces the contact resistance, especially if the elongated nanostructures comprise a conductive material. In this case, the physical contact between the elongated nanostructures and the diffusion layer also establishes an electrical connection with low contact resistance between the elongated nanostructures 311 and the diffusion layer 320. Since the elongated nanostructures 311 are bonded to the separator element 310, this results in a reduced contact resistance between the separator element 310 and the diffusion layer 320. Preferably, the elongated nanostructures 311 should be arranged such that they are in contact with the material of the diffusion layer over a majority of their surface area. The majority of the surface area of ​​the elongated nanostructures may be more than 50% of said surface area.

[0070] According to an embodiment, the separator element 310 is a planar element or plate. According to another embodiment, the diffusion layer is also a planar element. A plate or planar element is elongated in two dimensions and relatively thin in a third dimension. The two dimensions in which such an element elongates define a plane in which the element extends.

[0071] Each planar element generally includes two broad boundary surfaces, which are mostly parallel to the extension plane and are generally the broadest boundary surfaces of the element. These boundary surfaces may be referred to as the first and second sides of the planar element. The separator element 310 and the diffusion layer 320 are arranged such that the first side of the separator element 310 is adjacent to the first side of the diffusion layer 320, and the extension planes of the separator element and the diffusion layer may be generally parallel. The elongated nanostructures 311 may then be attached to the first side of the separator element 310 and pass beyond the surface of the first side of the diffusion layer 320.

[0072] The plurality of elongated nanostructures 311 may include elongated carbon nanostructures, which may be, for example, any of carbon nanofibers, carbon nanowires, and carbon nanotubes.

[0073] Due to their good electrical conductivity and chemical stability, carbon materials are often used in electrochemical cells, for example as materials for catalyst supports and diffusion layers. Specifically, carbon materials are used on both the anode and cathode sides in fuel cells, and on the cathode side in electrolyzers. Due to their chemical stability, elongated carbon nanostructures have the advantage that non-conductive compounds are less likely to form on the surface, which is advantageous for maintaining low electrical contact resistance. The presence of carbon nanostructures on the surface of the separator element 310 can also prevent chemical degradation of the separator element itself by shielding the surface from the chemical environment of the cell.

[0074] The shape and structure of the elongated carbon nanostructures can be modified by adjusting the conditions under which the nanostructures are grown to obtain, for example, a desired density or shape of the nanostructures, a desired thickness or length of the nanostructures, or a desired number of nanostructures per surface area. A particular advantage of carbon nanofibers and nanowires is their high stiffness and rigidity, which makes them less susceptible to deformation and more likely to maintain their desired orientation relative to the separator element 310 when the fuel cell is assembled by methods such as pressing the components together.

[0075] The plurality of elongated nanostructures 311 may include elongated metallic nanostructures or nanostructures comprising any of copper, aluminum, silver, gallium arsenide, zinc oxide, indium phosphate, gallium nitride, indium gallium nitride, indium gallium arsenide, silicon, or other materials.

[0076] As mentioned above, an elongated nanostructure has one dimension that is larger than the other. The axis along this dimension will be considered the length axis of the elongated nanostructure, and the size of the nanostructure in this dimension will be considered the nanostructure length. The size of the nanostructure in the other dimension can be referred to as the nanostructure width, or for a generally cylindrical nanostructure, the nanostructure diameter.

[0077] The length axis of the elongated nanostructures also indicates the orientation of the nanostructures. For example, an elongated nanostructure can be said to be oriented perpendicular to the separator element 310 if its length axis extends perpendicular or nearly perpendicular to the extension plane of the separator element 310, or equivalently if its length axis is parallel or nearly parallel to the normal vector of the extension plane.

[0078] It is advantageous to have uniformly oriented elongated nanostructures for connecting the separator elements and the respective diffusion layers. Thus, at least some of the elongated nanostructures 311 may be oriented parallel to one another and extend along a direction perpendicular or nearly perpendicular to the extension plane of the separator elements 310.

[0079] This should not be taken to mean that the nanostructures are perfectly straight or perfectly perpendicular to the extension plane of the separator element 310. The nanostructures may extend along a direction generally perpendicular to the extension plane, which may be taken to mean that the nanostructures may be slightly tilted with respect to the normal vector of the extension plane, or that the nanostructures may be curved back and forth to form a spiral or wave shape. Rather, the nanostructures extend in the general direction of the normal vector. In this context, slightly tilted may mean that the angle between the length axis of the elongated nanostructure and the normal vector of the extension plane may be less than 45 degrees, and preferably less than 30 degrees.

[0080] In another embodiment, at least some of the elongated nanostructures 311 may extend at an angle relative to a normal to the extension plane of the separator element 310. The angle between the length axis of the elongated nanostructures and the normal to the extension plane may be, for example, between 10 and 80 degrees. The angle may depend, for example, on the properties of the diffusion layer, such as void fraction and pore size, or the manufacturing method used to fabricate the separator element device 300.

[0081] According to embodiments, the length axes of individual nanostructures may have different angles with respect to the normal vector, such that not all elongated nanostructures in the plurality of elongated nanostructures are perfectly parallel to each other. As an example, the angle between the length axes of two elongated nanostructures may be less than 45 degrees, preferably less than 30 degrees. As another example, the angle between the length axes of two elongated nanostructures may be 45 degrees or more.

[0082] The length and width of the elongated nanostructures may be adjusted, for example, depending on the properties of the diffusion layer 320. As one example, the width of the elongated nanostructures may be adjusted to be smaller than the pore size of the porous material contained within the diffusion layer. As another example, the nanostructure length may be adjusted to promote contact between the elongated nanostructures and the diffusion layer material, for example, the nanostructure length may be similar to or larger than the pore size of the diffusion layer material.

[0083] According to an embodiment, the length of at least one structure of the elongated nanostructures measured along an axis extending perpendicular to the extension plane of the separator element 310 may be between 10 and 20 micrometers.

[0084] In particular, the diffusion layer 320 may include a porous material that includes a plurality of fibers. Fibers are generally elongated structures with one dimension larger than the other. These shapes may therefore be characterized by a length in the elongated dimension and a thickness in each dimension perpendicular to the elongated dimension. For generally cylindrical fibers, the thickness may be the fiber diameter. If the thickness is not constant along the length of the fiber, the thickness may be the average thickness. The length of the elongated nanostructures may be adapted to the thickness of the fibers contained within the porous material to increase the mechanical and electrical contact between the fibers and the elongated nanostructures. In one example, the length of the elongated nanostructures may be similar to or larger than the average thickness of the fibers.

[0085] The spacing between the elongated nanostructures in the plurality of elongated nanostructures 311 may be adapted to the structure of the porous material contained within the diffusion layer 320. For example, the spacing may be adapted to the average spacing between pores in the porous material. If the porous material comprises fibers, the spacing may be at least as large as the thickness of the fibers.

[0086] The orientation of a fiber is generally considered to be the direction of its elongated dimension. According to one example, if the porous material contained within the diffusion layer 320 includes fibers, these fibers may be randomly oriented to form a felted or paper-like material, such as carbon felt or graphite felt. According to another example, the fibers may follow two main orientation directions that are approximately perpendicular to each other, such as in a woven fabric.

[0087] The fibers contained in the porous material may be oriented generally parallel to the extension plane of the separator element 310. This may be taken to mean that the majority of the fibers are oriented at an angle of less than 45 degrees to the extension plane, and preferably at an angle of less than 30 degrees to the extension plane. If the elongated nanostructures contained in the separator element 310 are oriented generally perpendicular to the extension plane, the elongated nanostructures and the fibers contained in the porous material may be generally perpendicular to each other. The elongated nanostructures can then more easily extend into the spaces between the fibers contained in the porous material and can also maintain contact with the fibers contained in the porous material along their length. This may improve the mechanical and electrical contact between the separator element 310 and the diffusion layer 320.

[0088] As an example, the fibers contained within the porous material may have a thickness of 1 to 10 micrometers. As another example, the fibers may be nanofibers or nanotubes.

[0089] According to an embodiment, the diffusion layer 320 may include a porous carbon material. The porous carbon material may include a plurality of carbon fibers that may extend generally parallel to an extension plane of the separator element 310 and / or generally perpendicular to the plurality of elongated nanostructures 311.

[0090] Separator elements used in electrochemical cells often include a flow field arrangement. Flow field arrangements are used to promote uniform distribution of reactants throughout the separator element and to facilitate removal of reaction products. A schematic diagram of one example of a flow field arrangement is shown in FIGS. 4A and B. Flow field arrangement 400 includes a number of grooves known as channels 410 that are separated by ridges known as ribs or channel supports 420. Gases and liquids can flow along channels 410 and thus spread throughout the separator element. As an example, the flow field arrangement may be formed by scoring into separator element 310 to form channels 410. As another example, the flow field arrangement may be formed by depositing material on a surface of separator element 310 to form channel supports 420.

[0091] When the separator element is a planar element, the flow field devices are generally arranged on said first and second sides, i.e. on the surfaces of the element that are parallel to the extension plane of the element. In the separator element devices described herein, the flow fields may be arranged on the surface of the separator element that faces the diffusion layer. When the separator element is a bipolar plate used in a stack of electrochemical cells, two flow field devices may be arranged on opposite sides of the separator element.

[0092] 4A and 4B is known as a straight parallel flow field device because the arrangement of ribs promotes parallel flow of gas and / or liquid through adjacent flow channels. Other flow field device designs may be used, such as serpentine, interdigitated, or pin-type flow field devices.

[0093] Thus, at least one of the separator elements may include a flow field device 400. The flow field device 400 may be disposed on a surface of the separator element 310 that faces the diffusion layer 320. The flow field device may include a number of flow channels 410 separated by a number of flow channel supports 420, the flow channels 410 being arranged to promote uniform distribution of gas / liquid throughout the flow field device 400.

[0094] The flow channel supports 420 form raised sections, ridges, or bumps in the surface of the separator element so that they are in closer contact with the adjacent diffusion layer. Thus, a plurality of elongated nanostructures 311 may be bonded to a surface of at least one of the flow channel supports 420 of the flow field device 400. The surface to which the elongated nanostructures 311 are bonded will in this case be the surface facing the diffusion layer 320. This is shown in FIG. 4C.

[0095] The chemical environment within an electrochemical cell may cause corrosion and / or degradation of some materials. Although carbon materials are generally sufficiently chemically stable to be used in fuel cells and on the cathode side in electrolyzers, they may require additional surface treatment for use, for example, on the anode side in electrolyzers. Other materials used in separator elements, such as stainless steel, may also require additional treatment to withstand the environment within an electrochemical cell. Thus, the separator element 310 may include a protective coating disposed thereon to increase corrosion resistance. As an example, the protective coating may include platinum, gold, or titanium, or a combination thereof. As another example, the protective coating may include a ceramic material or a metal oxide, such as aluminum oxide, cerium oxide, and zirconium oxide. The protective coating may include a carbon-based material. The protective coating may cover all or a portion of the separator element 310.

[0096] 6 and 3, a method of manufacturing a separator element device 300 including a separator element 310 and a diffusion layer 320 disposed adjacent to the separator element 310 is also disclosed. The method includes creating (S1) a plurality of elongated nanostructures 311, the elongated nanostructures 311 being attached to a surface of the separator element 310. The method also includes disposing (S2) the diffusion layer 320 adjacent to the separator element 310 such that the elongated nanostructures 311 extend into the diffusion layer 320, thereby coupling the separator element 310 to the diffusion layer 320.

[0097] The plurality of elongated nanostructures 311 may be produced through lithographic methods such as colloidal or nanosphere lithography, focused ion beam machining, and laser machining, among other methods. For nanofibers containing carbon or organic compounds, methods such as electrospinning or chlorination of carbides, such as titanium carbide, or metal organic compounds, such as ferrocene, may be used.

[0098] Producing (S1) the plurality of elongated nanostructures 311 may include growing (S11) the elongated nanostructures 311 on a substrate. Growing (S11) the elongated nanostructures 311 on a substrate may allow for wide tuning of properties of the nanostructures, including the height of the nanostructures, as well as the spacing between the nanostructures. According to an embodiment, the elongated nanostructures may be grown by plasma enhanced chemical vapor deposition.

[0099] The substrate may comprise silicon, glass, stainless steel, ceramic, silicon carbide, or any other suitable substrate material. The substrate may comprise a high temperature polymer, such as polyimide. Optionally, the substrate may be a component of an electrochemical cell, preferably a separator element 310.

[0100] Growing the elongated nanostructures 311 on the substrate (S11) may include depositing a growth catalyst layer on a surface of the substrate, and growing the elongated nanostructures 311 on the growth catalyst layer.

[0101] As used herein, a growth catalyst is a material that is catalytically active and promotes the chemical reactions involved in the formation of nanostructures.

[0102] The growth catalyst may include a material such as nickel, iron, platinum, palladium, nickel silicide, cobalt, molybdenum, gold, or alloys thereof. In one example, the growth catalyst layer may be 1-100 nm thick. In another example, the growth catalyst layer may include a plurality of growth catalyst particles.

[0103] Growing the elongated nanostructures 311 on the growth catalyst layer (S11) may include heating the growth catalyst layer to a temperature at which the nanostructures may be formed and providing a gas containing a reactant such that the reactant is in contact with the growth catalyst layer, where the reactant is a compound or mixture of compounds containing the chemical elements used to form the nanostructures. For carbon nanostructures, the reactant may include a hydrocarbon, such as methane or acetylene, or the reactant may include carbon monoxide.

[0104] Depositing the growth catalyst layer may include depositing a uniform growth catalyst layer and introducing a pattern onto the deposited uniform growth catalyst layer. Introducing a pattern onto the deposited uniform growth catalyst layer may also include modifying the thickness of the growth catalyst layer based on the pattern or selectively removing the growth catalyst layer at some locations. Introducing a pattern onto the growth catalyst layer may be achieved, for example, by lithographic methods, such as colloidal lithography or nanosphere lithography. Patterning the growth catalyst layer allows to control the number of nanostructures per surface area on the substrate.

[0105] The method may include depositing a conductive layer on a surface of the substrate. A growth catalyst layer may then be deposited on top of the conductive layer. After growing the elongated nanostructures, portions of the conductive layer that extend between or around the elongated nanostructures may be selectively removed. This removal may be accomplished, for example, by etching, such as plasma etching, pyrolytic etching, or electrochemical etching.

[0106] The conductive layer electrically grounds the substrate, which is advantageous for certain nanostructure growth methods, such as growth in a plasma, and can also prevent diffusion of atoms between the growth catalyst layer and the substrate.

[0107] According to an embodiment, the conductive layer may be 1 to 100 microns thick. According to another embodiment, the conductive layer may be 1 to 100 nm thick.

[0108] According to an embodiment, in addition to the substrate, growth catalyst layer, and conductive layer, additional layers may be present. Materials included in the additional layers may be selected to tailor the properties of the nanostructures being grown, facilitate vertically oriented growth, or improve the outcome of the growth process. The additional layers may include a separator element 310 for the electrochemical cell.

[0109] According to embodiments, deposition of any layer, including the conductive layer and the growth catalyst layer, may be performed by methods such as evaporation, plating, sputtering, molecular beam epitaxy, pulsed laser deposition, chemical vapor deposition, spin coating, spray coating, or other suitable methods.

[0110] According to embodiments, the elongated nanostructures may be grown on a substrate that includes a component of an electrochemical cell, preferably the separator element 310. According to other embodiments, the elongated nanostructures may be grown on some other substrate and subsequently transferred onto the separator element 310.

[0111] Optionally, additional surface treatments or conditioning may be used on the elongated nanostructures after growth. The surface treatment may be aimed at, for example, improving corrosion resistance, improving wettability of the surface of the nanostructures, reducing the surface resistivity of the nanostructures, or achieving some other beneficial effect. The surface treatment may include depositing a material on the surface of the nanostructures, for example by evaporation, plating, sputtering, molecular beam epitaxy, pulsed laser deposition, chemical vapor deposition, spin coating, spray coating, or other suitable method. The surface treatment may include a chemical treatment, for example etching or functionalization.

[0112] The method may also include at least partially coating (S12) at least one of the separator elements with a protective coating arranged to increase corrosion resistance. The protective coating may comprise a material such as gold, platinum, or titanium, and may be deposited by evaporation, plating, sputtering, molecular beam epitaxy, pulsed laser deposition, chemical vapor deposition, spin coating, spray coating, or other suitable method.

[0113] 1 and 3, a fuel cell 100 is also disclosed herein, comprising an ion exchange membrane 130, a first electrode catalyst layer 111 and a second electrode catalyst layer 121. The first electrode catalyst layer 111 and the second electrode catalyst layer 121 are disposed adjacent to the ion exchange membrane on either side of the ion exchange membrane. The fuel cell further comprises a first separator element arrangement 110 and a second separator element arrangement 120 disposed adjacent to the first electrode catalyst layer 111 and the second electrode catalyst layer 121, respectively, on the side of each electrode catalyst layer facing away from the ion exchange membrane 130. Each separator element arrangement comprises a separator element 310 and a diffusion layer 320 disposed adjacent to the separator element. At least one of the separator element arrangements 110, 120 is a separator element arrangement as described hereinabove. That is, the separator element arrangement includes a plurality of elongated nanostructures 311 also attached to a surface of a separator element 310, as described above, with at least some of the elongated nanostructures arranged to extend into the diffusion layer 320, thereby coupling the separator element 310 to the diffusion layer 320. Within the fuel cell, each separator element arrangement is arranged such that the diffusion layer 320 is sandwiched between the separator element and an adjacent electrocatalyst layer.

[0114] The ion exchange membrane 130, the electrode catalyst layers 111, 121, the diffusion layer 320, and the separator element 310 may be substantially planar elements as described above. Thus, when the first electrode catalyst layer 111 and the second electrode catalyst layer 121 are disposed on either side of the ion exchange membrane 130, this is because the first electrode catalyst layer 111 is disposed near the first side of the ion exchange membrane, and the second electrode catalyst layer 121 is disposed near the second side of the ion exchange membrane, such that the two electrode catalyst layers are separated by the ion exchange membrane 130, and the extending planes of the ion exchange membrane 130, the first electrode catalyst layer 111, and the second electrode catalyst layer 121 are substantially parallel to each other.

[0115] In other words, a fuel cell can be described as a stack of mostly planar elements, the stack including, in order, a first separator element, a first diffusion layer, a first electrocatalyst layer 111, an ion exchange membrane 130, a second electrocatalyst layer 121, a second diffusion layer, and a second separator element. The first separator element and the first diffusion layer together form a first separator element arrangement 110, and the second separator element and the second diffusion layer form a second separator element arrangement 120.

[0116] Fuel cells are often arranged in a stack having several cells connected in series, as shown in Figure 5. Accordingly, also disclosed herein is a fuel cell stack 500 including at least one fuel cell 100 as described above. The fuel cell stack 500 may include one or more fuel cells that do not include the separator element arrangement described herein, or may include a plurality of fuel cells 100 as described above.

[0117] 2 and 3, there is disclosed herein an electrolytic cell 200 comprising an ion exchange membrane 230, a first electrode catalyst layer 211 and a second electrode catalyst layer 221. The first electrode catalyst layer 211 and the second electrode catalyst layer 221 are disposed adjacent to said ion exchange membrane 230 on either side of the ion exchange membrane. The electrolytic cell further comprises a first separator element arrangement 210 and a second separator element arrangement 220 disposed adjacent to the first electrode catalyst layer 211 and the second electrode catalyst layer 221 on the sides of the first electrode catalyst layer 211 and the second electrode catalyst layer 221 facing away from the ion exchange membrane 230. Each separator element arrangement comprises a separator element 310 and a diffusion layer 320 disposed adjacent to the separator element.

[0118] At least one of the separator element devices 210, 220 is a separator element device as previously described herein, i.e., the separator element device comprises a plurality of elongated nanostructures 311 attached to a surface of the separator element 310 and arranged such that at least some of the elongated nanostructures extend into the diffusion layer 320, thereby coupling the separator element 310 to the respective diffusion layer 320. Within the electrolytic cell, each separator element device is arranged such that the diffusion layer 320 is sandwiched between the separator element 310 and an adjacent electrocatalyst layer.

[0119] The ion exchange membrane 230, the electrode catalyst layers 211, 221, the diffusion layer 320, and the separator element 310 may be substantially planar elements as described above. Thus, when the first electrode catalyst layer 211 and the second electrode catalyst layer 221 are disposed on either side of the ion exchange membrane 230, this means that the first electrode catalyst layer 211 is disposed near the first side of the ion exchange membrane 230, and the second electrode catalyst layer 221 is disposed near the second side of the ion exchange membrane 230, such that the two electrode catalyst layers are separated by the ion exchange membrane 230, and the extending planes of the ion exchange membrane 230, the first electrode catalyst layer 211, and the second electrode catalyst layer 221 are substantially parallel to each other.

[0120] In other words, a fuel cell can be described as a stack of mostly planar elements, the stack including, in order, a first separator element, a first diffusion layer, a first electrocatalyst layer 211, an ion exchange membrane 230, a second electrocatalyst layer 221, a second diffusion layer, and a second separator element. The first separator element and the first diffusion layer together form a first separator element arrangement 210, and the second separator element and the second diffusion layer form a second separator element arrangement 220.

[0121] Also disclosed is an electrolytic cell stack comprising at least one electrolytic cell as described above. The electrolytic cell stack may comprise one or more electrolytic cells that do not include the separator element arrangement described herein, or may comprise a plurality of electrolytic cells 100 as described above.

Claims

1. A separator element apparatus (300) for an electrochemical cell, the separator element apparatus comprising a separator element (310) and a diffusion layer (320) disposed adjacent to the separator element (310), the separator element comprising a plurality of elongated nanostructures (311), at least some of the elongated nanostructures being disposed to extend into the diffusion layer thereby coupling the separator element (310) to the diffusion layer (320).

2. The separator element apparatus (300) of claim 1, wherein the separator element (310) is a planar element.

3. The separator element apparatus of claim 1 or 2, wherein the plurality of elongated nanostructures (311) comprise elongated carbon nanostructures.

4. The separator element apparatus (300) of claim 3, wherein the elongated carbon nanostructures (311) comprise any of carbon nanofibers, carbon nanowires, and carbon nanotubes.

5. The separator element apparatus (300) of claim 1 , wherein the plurality of elongated nanostructures (311) comprises elongated metallic nanostructures.

6. 2. The separator element apparatus (300) of claim 1, wherein at least some of the elongated nanostructures (311) are oriented parallel to one another and extend along a direction perpendicular to an extension plane of the separator element (310).

7. The separator element apparatus (300) of claim 6, wherein a length of at least one structure of the elongated nanostructures measured along an axis extending perpendicular to an extension plane of the separator element (310) is between 10 and 20 micrometers.

8. 2. The separator element apparatus (300) of claim 1, wherein the separator element comprises a flow field device (400) disposed on a surface of the separator element (310) facing the diffusion layer (320), the flow field device comprising a plurality of flow channels (410) separated by a plurality of flow channel supports (420), the flow channels (410) arranged to promote uniform distribution of gas and / or liquid throughout the flow field device (400).

9. 9. The separator element device (300) of claim 8, wherein the plurality of elongated nanostructures are bonded to a surface of at least one of the flow path supports (420) of the flow field device (400), the surface facing the diffusion layer (320).

10. The separator element apparatus (300) of claim 1, wherein the separator element (310) includes a protective coating disposed to increase corrosion resistance.

11. The separator element apparatus (300) of claim 1, wherein the diffusion layer (320) comprises a porous carbon material.

12. 12. The separator element apparatus of claim 11, wherein the porous carbon material comprises a plurality of carbon fibers, the plurality of carbon fibers extending generally parallel to an extension plane of the separator element (310) and / or generally perpendicular to the plurality of elongated nanostructures (311).

13. A method of manufacturing a separator element device (300), the separator element device including a separator element (310) and a diffusion layer (320) disposed adjacent to the separator element (310), the method comprising: Producing (S1) a plurality of elongated nanostructures (311), said elongated nanostructures (311) being attached to a surface of said separator element (310); placing (S2) the diffusion layer (320) adjacent to the separator element (310) such that the elongated nanostructures (311) extend into the diffusion layer (320) thereby coupling the separator element (310) to the diffusion layer (320); A method of manufacturing a separator element device (300), comprising:

14. The method of claim 13 , wherein generating (S1) a plurality of elongated nanostructures (311) comprises growing (S11) the elongated nanostructures (311) on a substrate.

15. The method of claim 14, wherein growing (S11) the elongated nanostructures (311) on a substrate comprises depositing a growth catalyst layer on a surface of the substrate and growing the elongated nanostructures (311) on the growth catalyst layer.

16. The method of claim 15 , wherein depositing a growth catalyst layer comprises depositing a uniform growth catalyst layer and introducing a pattern onto the deposited uniform growth catalyst layer.

17. 17. The method of any one of claims 14 to 16, comprising depositing a conductive layer on a surface of the substrate.

18. The method of claim 13, comprising at least partially coating (S12) the separator element (310) with a protective coating arranged to increase corrosion resistance.

19. 10. A fuel cell (100) comprising an ion exchange membrane (130), a first electrode catalyst layer (111) and a second electrode catalyst layer (121), the first and second electrode catalyst layers being disposed adjacent to the ion exchange membrane on either side of the ion exchange membrane, the fuel cell further comprising a first separator element arrangement (110) and a second separator element arrangement (120) disposed adjacent to the first and second electrode catalyst layers (111, 121), respectively, on a side of each electrode catalyst layer facing away from the ion exchange membrane, each separator element arrangement comprising a separator element (310) and a diffusion layer (320) disposed adjacent to the separator element, at least one of the separator element arrangements (110, 120) being the separator element arrangement according to any one of claims 1.

20. A fuel cell stack (500) comprising at least one fuel cell (100) according to claim 19.

21. 1. An electrolytic cell (200) comprising an ion exchange membrane (230), a first electrode catalyst layer (211) and a second electrode catalyst layer (221), the first and second electrode catalyst layers being arranged adjacent to the ion exchange membrane (230) on either side of the ion exchange membrane, the electrolytic cell further comprising a first separator element arrangement (210) and a second separator element arrangement (220) arranged adjacent to each of the first and second electrode catalyst layers (211, 221) on a side facing away from the ion exchange membrane (230), each separator element arrangement comprising a separator element (310) and a diffusion layer (320) arranged adjacent to the separator element, at least one of the separator element arrangements (210, 220) being the separator element arrangement of any one of claims 1.

22. 22. An electrolytic cell stack comprising at least one electrolytic cell according to claim 21.

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