Compressible fluid distribution system in electrolytic device plates

Abstract

A method and system for fluid distribution in an electrolytic cell are disclosed. The disclosed carbon oxide electrolytic apparatus includes plates, a cathode region, a carbon oxide reaction gas that functions as a reducing substrate in the cathode region, a cathode-side fluid inlet, a cathode-side fluid outlet, an anode region, a liquid oxidizing substrate in the anode region, and a compressed electrically conductive mesh, the compressed electrically conductive mesh being (i) in electrical contact with the plates and (ii) providing a fluid path for the carbon oxide reaction gas from the cathode-side fluid inlet to the cathode-side fluid outlet through the compressed electrically conductive mesh.

Description

Technical Field

[0001] Cross-Reference to Related Applications This application claims the benefit of U.S. Provisional Application No. 63 / 535,577, filed on August 31, 2023, the entire content of which is hereby incorporated by reference in its entirety for all purposes.

Background Art

[0002] A carbon oxide electrolysis apparatus may include one or more electrolysis cells. A carbon oxide electrolysis cell can be constituted by a MEA (membrane electrode assembly) in which carbon oxide reduction is performed, and the MEA is sandwiched from both sides by plates that function as both electronic conductors and fluid distributors. The fluid distribution function can be provided by channels etched or otherwise formed on the surface of the plate, and these channels, while in contact with the MEA, provide fluid flow paths along the surface of the plate from one side of the electrolysis cell to the other side.

Summary of the Invention

[0003] The present specification discloses methods and systems related to fluid distribution in an electrolysis cell. The fluid distribution system may be for distributing reactor feedstock or electrolyte between plates for an electrolysis apparatus. The fluid distribution system may be for distributing gas or liquid through the interior of the electrolysis cell. The fluid distribution system may be configured to allow the fluid to contact the electrode catalyst of the electrolysis cell while flowing from the fluid inlet to the fluid outlet. The fluid distribution system may also be configured to provide an electrically conductive path across the electrolysis cell from the anode to the cathode of the electrolysis cell.

[0004] The fluid distribution system may be compressible so as to be compressed together with the electrolytic cell when the electrolytic cell is compressed to form a cell seal. The fluid distribution system may include a compressible flow field. The compressible flow field may be formed of an electrically conductive, compressible material. The compressible flow field disclosed herein may be formed of a single compressible, electrically conductive mesh having the same shape as the active region of the electrolytic cell. Alternatively, the compressible flow field disclosed herein may be formed of a plurality of separate, compressible, electrically conductive material pieces having the same shape as the patterned channels in the active region of the electrolytic cell. The patterned channels may be formed by etching, machining, stamping, deep drawing, or other methods and may be placed on the surface of the electrode plates of the electrolytic cell.

[0005] Certain compressible fluid distribution systems disclosed herein may offer significant advantages in that they eliminate the need to pattern channels on the electrode surface. This is because, by introducing a single compressible electrically conductive mesh placed on the electrode surface, the compressible fluid distribution system can provide functionality equivalent to that of patterned channels. This aspect of the fluid distribution system reduces the cost of the cell by eliminating the need for precise machining of fluid channels. Furthermore, certain carbon oxide electrolytic devices require high compression (e.g., 1 megapascal) on the cell components to ensure good catalytic performance. For example, a carbon monoxide electrolytic device with a copper catalyst on the cathode side may require high compression to ensure reliable contact between the catalyst and the cell membrane. In such electrolytic devices, the use of a compressible electrically conductive mesh is particularly advantageous, as the mesh can uniformly distribute the compressive force across the entire electrode surface compared to a fluid distribution system using patterned channels, where the compressive force is distributed only in the negative electrode region of the channel.

[0006] Configurations with patterned channels on the electrode plates have been conventionally used in carbon oxide electrolytic devices having an aqueous phase on one side of the membrane and a gas phase on the other side, due to the specific configuration and operating characteristics of the cells. In particular, these cells can utilize a pressure difference of up to 0.8 bar to prevent the aqueous electrolyte from leaking through the membrane to the gas phase side. This pressure difference can be maintained by controlling the amount of feedstock and electrolyte introduced into the fluid distribution system on both sides of the membrane. Until now, it was thought that only fluid distribution systems formed by patterned channels had sufficient characteristics to precisely control this pressure difference through the introduction of feedstock and electrolyte. However, the inventors of the present invention have found that a compressible mesh of an electrically conductive material with appropriately selected pore sizes can achieve the advantages of the compressible electrically conductive mesh mentioned in the previous paragraph while simultaneously providing sufficient control of the pressure difference.

[0007] In a particular embodiment, a carbon oxide electrolytic cell is provided. The carbon oxide electrolytic cell includes an electrode plate, a cathode region, a carbon oxide reaction gas that functions as a reducing substrate in the cathode region, a cathode-side fluid inlet, a cathode-side fluid outlet, an anode region, a liquid oxidizing substrate in the anode region, and a compressed electrically conductive mesh. The compressed electrically conductive mesh (i) is in electrical contact with the electrode plate, and (ii) provides a fluid path for the carbon oxide reaction gas from the cathode-side fluid inlet to the cathode-side fluid outlet through the compressed electrically conductive mesh.

[0008] In a particular embodiment, a carbon oxide electrolytic cell is provided. The carbon oxide electrolytic cell includes an electrode plate, a cathode region, a carbon oxide reaction gas that functions as a reducing substrate in the cathode region, a cathode-side fluid inlet, a cathode-side fluid outlet, a membrane, and a compressed electrically conductive mesh. The compressed electrically conductive mesh (i) comprises steel, (ii) is in electrical contact with the electrode plate, and (iii) provides a fluid path for the carbon oxide reaction gas from the cathode-side fluid inlet to the cathode-side fluid outlet through the compressed electrically conductive mesh. A separate carbon-based gas diffusion layer supporting a catalyst is also disposed between the compressed electrically conductive mesh and the membrane.

[0009] In a particular embodiment, a method for forming an electrolytic cell is provided. The method includes the step of attaching an electrode plate to a first compression plate so that the electrode plate and the first compression plate form an electrode fluid inlet and an electrode fluid outlet. However, in some modifications, the cell frame may include a fluid inlet and a fluid outlet for each cell. The method further includes the steps of placing an electrically conductive mesh on the electrode plate, placing an electrode catalyst on the electrically conductive mesh, and compressing the electrically conductive mesh by compression using the first compression plate to form a compressed electrically conductive mesh so that the compressed electrically conductive mesh is configured to allow fluid to flow through the compressed electrically conductive mesh from the electrode fluid inlet to the electrode fluid outlet. [Brief explanation of the drawing]

[0010] The accompanying drawings illustrate various embodiments of the systems, methods, and other aspects relating to this disclosure. Those skilled in the art will understand that the boundaries of elements shown in the drawings (e.g., boxes, sets of boxes, or other shapes) are merely examples of boundaries. In some examples, one element may be designed as multiple elements, or multiple elements may be designed as a single element. Furthermore, an element shown as an internal component of one element in one example may be implemented as an external component in another, or vice versa. Moreover, the elements are not necessarily drawn to scale. A non-limiting and non-exclusive description is given with reference to the following drawings. The components in the drawings are not necessarily to scale, and the emphasis is rather on illustrating the principles.

[0011] [Figure 1] Figure 1 is an exploded view of an electrolytic stack according to a specific embodiment of the invention disclosed herein.

[0012] [Figure 2] Figure 2 is an exploded view of an electrolytic cell according to a specific embodiment of the invention disclosed herein.

[0013] [Figure 3] Figure 3 includes a cross-sectional view of an uncompressed cell of an electrically conductive, compressible porous material and a cross-sectional view of the same electrically conductive, compressible porous material in a compressed state, according to a particular embodiment of the invention disclosed herein.

[0014] [Figure 4] Figure 4 shows an electrode plate in an electrolytic cell according to a specific embodiment of the invention disclosed herein, and the same electrode plate with a conductive mesh placed on it.

[0015] [Figure 5]FIG. 5 illustrates an electrode plate in an electrolytic cell having a gasket disposed on a cell, and the same electrode plate with a membrane assembly disposed on the gasket, in accordance with a specific embodiment of the invention disclosed in the present specification.

[0016] [Figure 6] FIG. 6 shows various configurations of compressible porous meshes having electrical conductivity, in accordance with a specific embodiment of the invention disclosed in the present specification.

[0017] [Figure 7] FIG. 7 includes two plots showing fluid resistance of two compressed electrically conductive meshes, in accordance with a specific embodiment of the invention disclosed in the present specification.

[0018] [Figure 8] FIG. 8 includes two plots showing a comparison between the configuration of the conductive mesh and a cell having only a standard patterned flow path.

[0019] [Figure 9] FIG. 9 includes two plots showing voltage and output selectivity for two configurations of an electrolyzer, in accordance with a specific embodiment of the invention disclosed in the present specification.

[0020] [Figure 10] FIG. 10 is a flowchart of a method of forming an electrolytic cell including a fluid distribution system, in accordance with a specific embodiment of the invention disclosed in the present specification.

[0021] [Figure 11] FIG. 11 shows a modular electrolytic cell, in accordance with a specific embodiment of the invention disclosed in the present specification.

[0022] [Figure 12] FIG. 12 shows a modular electrolytic cell, in accordance with a specific embodiment of the invention disclosed in the present specification. DETAILED DESCRIPTION OF THE INVENTION

[0023] The following describes in detail various aspects and variations of the systems and methods described herein, including implementation examples and embodiments. While several exemplary variations of the systems and methods are described here, other variations may include systems and methods that combine all or some of the aspects described herein in an appropriate manner.

[0024] This specification discloses in detail methods and systems for fluid distribution in electrolytic cells. The methods and systems disclosed in this section are non-limiting embodiments of the invention and are provided for illustrative purposes only and should not be used to limit the overall scope of the invention. It should be understood that the disclosed embodiments may or may not overlap with each other. Accordingly, some parts of one embodiment or a particular embodiment may or may not be included in the scope of another embodiment or a particular embodiment, and vice versa. Different embodiments relating to different aspects may be implemented in combination or individually. Those skilled in the art may conceive of numerous different combinations and subcombinations from the representative embodiments shown within the broad framework of the invention, but these should not be construed as excluded simply because they are not expressly shown or described.

[0025] This specification discloses methods and systems for forming seals and flow channels in an electrolytic apparatus. In certain embodiments, the electrolytic apparatus includes a compressible fluid distribution system. The compressible fluid distribution system may include a compressible porous material that forms the flow channels of the electrolytic apparatus, such as a porous foam, a porous metal, or a compressible metal. The compressible fluid distribution system may be placed on a plate of an electrolytic apparatus stack, which is completely flat or at least simplified compared to a standard electrolytic apparatus stack plate. The compressible porous material may be surrounded by a gasket material that forms a seal between adjacent channels in the fluid distribution system. The gasket is a loose gasket placed on the surface of the plate, which can be compressed and held in place when the plate is compressed within the electrolytic apparatus stack.

[0026] The electrolytic apparatus disclosed herein may be a carbon oxide electrolytic apparatus that converts carbon oxides such as carbon dioxide and carbon monoxide into useful products in response to a voltage applied between the anode and cathode of the electrolytic apparatus. Both the anode and cathode are referred to herein by the term "electrode." The useful products may be produced through a reduction reaction in which carbon oxides are reduced at the cathode side of the electrolytic apparatus, and correspondingly through an oxidation reaction in which the reactants are oxidized at the anode side of the electrolytic apparatus. The useful products may be, but are not limited to, chemical substances such as carbon monoxide, hydrogen, oxygen, alkanes, alkenes, alcohols, carboxylic acids, and aldehydes.

[0027] The electrolytic apparatus described above may include one or more cells defined by an active region where an electrochemical reaction to produce useful products takes place. The electrolytic apparatus may utilize fluid flow fields that allow fluid to flow through the active region to transport reactants into the active region and products out of the active region. The fluid flow may occur between carbon oxides and catalysts that enable the conversion of reactants into useful products, and electrode plates. The plates are referred to as electrode plates because they are associated with the different polarities of the electrolytic cell, with the anode associated with positive polarity and the cathode associated with negative polarity. The fluid flow fields may be provided on both sides of the cell, with one fluid flow field associated with the cathode and another with the anode. The fluid flow fields may be configured to accommodate gaseous or liquid-phase fluids. For example, the cathode side may have a fluid flow field for accommodating a gaseous fluid such as humidified carbon monoxide, and the anode side may have a fluid flow field for accommodating a liquid-phase fluid such as an alkaline electrolyte containing useful products produced in the liquid phase (e.g., liquid-phase carboxylates that can be isolated and converted to carboxylic acids).

[0028] The fluid channel described above may constitute part of a fluid path that traverses the cell. The fluid path may include a fluid flow that comes into contact with the electrodes and electrode catalyst of the cell. The fluid flow may be a gaseous flow or a liquid flow. The fluid may be the reactants or electrolyte of the cell. For example, the electrode catalyst may be a cathode catalyst, and the fluid flow may be a gaseous cathode-side feedstock flow. As another example, the electrode catalyst may be an anode catalyst, and the fluid flow may be an aqueous anode-side feedstock flow.

[0029] An electrolytic cell according to this disclosure may include an electrode assembly, such as a MEA (membrane electrode assembly), which is sandwiched between channels located on both sides thereof, enabling reduction and oxidation reactions that produce the useful products described above by allowing ions to pass through a membrane between the cathode and anode. The channels may be configured to ensure both (i) electrical contact between the electrodes of the electrolytic cell and the MEA, and (ii) a fluid path for transporting reactants or products within the electrolytic cell. The MEA may include zero, one, or two electrodes, each consisting of a membrane and a diffusion layer (e.g., a porous medium that allows ion movement across the cell). The membrane, electrodes, and diffusion layer may include or be coated with catalytic material. The anode side of the assembly may include an oxidation catalyst, and the cathode side of the assembly may include a reduction catalyst. Both reduction-promoting catalysts and oxidation-promoting catalysts are referred to herein by the term "electrode catalyst." In certain embodiments, each cell may comprise two assemblies with a separation region between them to allow for the removal of products designed to be separated and retained from the product flow or reaction flow on the anode or cathode side. The fluid flow flowing through the channel into the cathode side may supply reactants to be electrochemically reduced. These reactants may consist of, but are not limited to, solutions containing carbon dioxide, carbon monoxide, carbonates or bicarbonates, water in liquid or vapor form, argon, nitrogen, or water containing dissolved salts. The fluid flow flowing through the channel into the anode side may supply reactants to be electrochemically oxidized. These reactants may consist of water in liquid form, or water containing dissolved salts (CsOH, KOH, CsHCO3, Cs2CO3, CsCl, CsBr, CsI, KHCO3, K2CO3, KCl, KBr, KI, NaHCO3, Na2CO3, NaCl, NaBr, NaI). The presence of ions in the fluid flow may also be beneficial in promoting the ionic conductivity of the membrane.

[0030] As described above, an MEA for a carbon monoxide electrolytic apparatus may be provided as an example. An MEA for a carbon monoxide electrolytic cell may be characterized by (i) a cathode comprising a porous electrode support (e.g., a gas diffusion layer (GDL)) and a carbon oxide reduction catalyst layer (integrated with or deposited on the cathode material), (ii) an ion-conducting medium such as, but not limited to, one or more films, an ion-conducting electrolyte, a diaphragm, or an oxide-conducting material such as ceramics, and (iii) an anodic layer comprising an oxidation catalyst that promotes the oxidation of reactants (e.g., water). While examples of carbon monoxide electrolytic apparatuses are used throughout this disclosure, the embodiments disclosed herein are equally applicable to alternative electrolytic apparatuses that more commonly use channels and MEAs.

[0031] Multiple electrolytic cells can be arranged in various configurations within an electrolytic apparatus. When electrolytic cells are arranged in series, the reactor configuration of such an electrolytic apparatus can be called an electrolytic stack. In this case, the anode (the site where oxidation occurs) of one cell is electrically connected to the cathode (the site where reduction occurs) of the next cell, and so on. Electrolytic cells can have various geometric shapes, including but not limited to circular and polygonal shapes. These geometric shapes can be rectangular, square, pentagonal, hexagonal, or octagonal. In the case of an electrolytic stack, the other elements of the stack can have the same or different shapes.

[0032] The electrodes of an electrolytic stack can be configured in various ways. These electrodes can provide mechanical support in the electrolytic cells, function as electron conductors in the stack, and further, distribute fluids through the electrolytic cells to introduce and remove reactants and products into the active region of the electrolytic apparatus. In certain embodiments, consecutive MEAs within an electrolytic stack are physically separated by a bipolar plate (BPP). The BPP may also ensure series electrical connections between the consecutive MEAs. The electrodes may include channels and fluid ports for each electrolytic cell in the stack. In stacks using BPPs, at the ends of the stack, only one side of the electrode contacts the MEA at the end. Such an electrode may be referred to as a monopolar plate.

[0033] Electrolytic stacks can be configured in various ways. Current collectors may be provided at both ends of the stack to allow connection to an external power source. The stack may be assembled in a stack housing comprising end plates that ensure mechanical support, guarantee electrical insulation, and provide fluid ports (inlet / outlet) for both reaction flow and product flow. The stack may include means for compressing the stack to prevent fluid leakage within the system. For example, the stack may form a seal by being compressed together with gasket material placed between the various layers of the stack. As disclosed herein, the gasket may be a loose gasket that is not molded to conform to the shape of the stack components, but may still provide sufficient sealing for the operation of the electrolytic stack.

[0034] Figure 1 is an exploded view of an electrolytic stack 100 according to a particular embodiment of the invention disclosed herein. As shown, the electrolytic stack 100 includes a first end plate 101 and a second end plate 102. The stack further includes a plurality of gaskets 103a, 103b, 103c, and 103d dispersed within the plurality of layers of the electrolytic stack 100 to prevent leakage and provide electrical insulation between cells. The first end plate 101 and the second end plate 102 may be compression plates fastened to compress the gaskets to form a seal. The gaskets include notches for inter-cell fluid interfaces 104 to allow fluid to flow through the cells of the stack. The inter-cell fluid interfaces 104 have four interfaces for providing fluid inlets and fluid outlets for each of the two polarity sides of the illustrated cells. The electrolytic stack 100 further includes two dipole plates (dipole plate 105a and dipole plate 105b). The bipolar plate includes channels (tunnels or grooves) to allow fluid to be transferred from the inter-cell fluid interface to the active region of the cell. The active region is formed over the same area as the membrane electrode assembly 108. The gasket further includes a central notch, such as a notch 109, over the same area as the active region, to allow the fluid guided by the plate to reach the membrane electrode assembly 108. For the sake of simplification, not all elements of the stack are illustrated. For example, multiple cells are shown as a stack 107.

[0035] In certain embodiments, a frame may be added to the top of the electrolytic stack to ensure airtightness with the gasket on the top plate of the stack. This frame may be a rigid plastic frame. In certain embodiments, this frame may be positioned around the periphery of two compression plates located on either side of the stack.

[0036] Plates such as the dipole plates 105a and 105b described herein may be formed from stainless steel (in particular, but not limited to, 316L), titanium, graphite, or any conductive material. The dipole plates (plates) may have one or more surface coatings (e.g., including Ti, Cr, Nb, Ni, Fe) on one or more surfaces that come into contact with one or more MEAs to reduce contact resistance and improve chemical resistance (in particular corrosion resistance). The plate shown in Figure 1 includes a notch for an inter-cell fluid interface, but in alternative embodiments, the fluid interface may not penetrate the plates but instead be formed on the edges of the plates. In certain embodiments, each cell in the stack may include an additional cell frame (not shown), i.e., a frame surrounding the electrochemical cell placed between the two plates. In some modifications, the fluid interface may extend through the cell frame partially or entirely. In certain embodiments with additional cell frames, the electrode plates may be flat metal sheets, and a single cell frame may include fluid inlet and outlet interfaces for both the anode and cathode sides of the cell. While all plates shown in Figure 1 are rectangular and uniform in shape, in alternative embodiments, plates may have different shapes, such as circular or triangular, and may also have different shapes within the same stack.

[0037] Figure 2 is an exploded view of an electrolytic cell 200 according to a particular embodiment of the invention disclosed herein. The electrolytic cell 200 includes two dipole plates (plates; dipole plate 205a and dipole plate 205b). The dipole plates include fluid interfaces (fluid interfaces 209a, 209b, 209c, and 209d) that guide fluid from the inter-cell fluid interface to the active region of the cell and from the active region to the inter-cell fluid interface. These fluids may then come into contact with both sides of the membrane electrode assembly 208, but leakage is prevented by gaskets 203a, 203b, 203c, and 203d. The membrane electrode assembly 208 may include one or two electrodes, each comprising an electrode catalyst, separated by a membrane or separator. The cell further includes porous channels 210a and 210b. In the illustrated example, the channels are formed by a compressible electrically conductive mesh having the same shape as the active region of the electrolytic cell, and the electrode plates are not provided with any channels formed by machining or other means. This configuration offers significant advantages in terms of ease of manufacturing the entire electrolytic stack because it eliminates the process of forming complex patterns on the electrode plates as in other methods. In alternative embodiments, the channels may be patterned on the electrode plates, or another structure may form the channels in the active region. In these embodiments, the channels may be filled with a compressible electrically conductive material that serves a similar purpose to the single compressible electrically conductive mesh in the embodiment of the electrolytic cell 200.

[0038] As mentioned above, the gasket system of an electrolytic stack serves several purposes. To maintain efficiency and ensure good operation of the electrolytic device, two consecutive plates must not be in direct ohmic contact. The passage of current from one plate to the next should ideally be ensured only by the transport of ions through the central membrane of the MEA, in order to minimize current leakage between subsequent cells and maximize the energy efficiency of the reactions occurring at each electrode of the MEA. For this purpose, the gasket system can prevent contact between adjacent plates. Furthermore, the use of ion-containing solutions, such as aqueous solutions containing ions (but not limited to these), at the anode may cause electrical contact between two adjacent electrode plates, leading to current leakage. The gasket system can reduce or eliminate the effects of these leakage currents. In addition, the gasket system may consist of gaskets placed at the interface between the MEA and the bipolar plates (BPP), as well as around the intercellular fluid ports, providing airtightness to the fluid compartments. The above-mentioned gasket may be formed as a single component or as a plurality of separate components, and may be positioned around both the electrochemically active region and the fluid port.

[0039] Based on the requirements of the gasket system, the system is required to satisfy certain design constraints. In certain embodiments, the gasket system needs to function in parallel with parts of the electrolytic cell, such as the gas diffusion layer (GDL) of the MEA, and as a result, several design constraints may be imposed. As an example of the design constraints imposed on the gasket system, the gasket system should operate within a compression tolerance that ensures the airtightness of the electrolytic reactor and good compression of the GDL. Furthermore, the gasket system should be mechanically stable so as to avoid creep deformation. In general, the compression of the active surface of the cell should be within its optimal operating range to ensure the following: proper electrical contact between the plate and the components of the MEA (e.g., GDL), contact that allows for the exchange of different chemical species between the electrode and other components of the MEA (e.g., electrolyte and GDL), sufficient porosity of the diffusion layer connecting the flow path and the electrode (e.g., GDL) to ensure the transport of reactants and products of the electrochemical reaction, and airtightness of the assembly.

[0040] Generally, loose gaskets placed on the flat surface of a plate have a narrow range of allowable compression. As a result, molded, and therefore more expensive, gaskets are usually preferred. However, variations in the properties of the components during compression may, in some cases, prevent a seal from being achieved, or the compression of the active region may become excessively high, resulting in insufficient movement of chemical or ionic species through the MEA. On the other hand, by using channels formed from a compressible porous mesh material, it is possible to achieve the objectives of the gasket system listed above, while also providing optimal compression of the active surface of the cell, using a plate with a flat surface and a loose gasket. Therefore, by using an electrically conductive mesh as a compressible porous material to form the channels of an electrolytic device, design simplification and cost reduction can be achieved in both the design of the gasket system and the plate for the electrolytic stack.

[0041] In certain embodiments, a loose gasket is positioned to contact the flat surface of the dipole plate, exhibiting the minimum deformation range necessary to achieve the desired objectives listed above. In these embodiments, conventional channels are replaced with channels formed of a compressible porous material, such as a mesh of porous metal or expanded metal. The resulting system allows for the use of a flat, relatively low-cost plate and a loose gasket positioned to contact the plate, while satisfying the constraints on the compression of components in the active region of the cell. Thus, the plate can be flat or a simplified configuration and may have flat sealing surfaces on both sides. The internal notches of the gasket can accommodate the aforementioned electrically conductive, compressible porous material, which functions as a channel. The compressibility of the porous material used as a channel can absorb geometric variations, tolerances, and cumulative effects of different elements while satisfying the above constraints. Channels formed of an electrically conductive, compressible porous mesh can ensure appropriate ion conductivity within the electrolytic device, proper flow of electrolytes, products, and reactants through the channels, and uniform compression of the MEA.

[0042] Figure 3 includes a cross-sectional view of an electrically conductive, compressible porous mesh 302 (e.g., material) in an uncompressed cell 300, and a cross-sectional view of the same electrically conductive, compressible porous mesh 302 in a compressed cell 310, according to a particular embodiment of the invention disclosed herein. The electrically conductive, compressible porous mesh 302 is surrounded by a gasket 304, which clamps the electrically conductive, compressible porous mesh 302 in the illustrated cross-section and also surrounds the electrically conductive, compressible porous mesh 302 when viewed from above. The electrically conductive, compressible porous mesh 302 is positioned on a MEA 301. The electrically conductive, compressible porous mesh 302 can provide an ohmic connection between an electrode plate, such as a bipolar plate 306, and an electrode catalyst on the MEA 301. The ohmic connection can be formed in the plane of the cross-section in Figure 3. The electrically conductive, compressible porous mesh 302 can form a plurality of holes relative to the electrode fluid inlet of the cell. The collection of holes may have a larger surface area in the compressed electrically conductive mesh compared to the surface area of ​​the holes in the uncompressed state. In any case, the electrically conductive, compressible porous mesh 302 can provide fluid flow through the holes from a fluid inlet to a fluid outlet. The electrically conductive, compressible porous mesh 302 shown in Figure 3 is partitioned by gaskets 304 on two sides, by an electrode fluid inlet on a third side located outside the plane of the paper, and by an electrode fluid outlet on a fourth side opposite to the third side.

[0043] The figure also shows a second electrically conductive, compressible porous mesh 303, which is positioned relative to the gasket 305 in the same manner as the positional relationship of the gasket 304 relative to the electrically conductive, compressible porous mesh 302. The electrically conductive, compressible porous mesh 302 and the electrically conductive, compressible porous mesh 303 may be formed from a mesh of an electrically conductive, compressible foam or other structured conductive material.

[0044] Of the above MEA301, the electrode catalyst located on the side facing the electrically conductive, compressible porous mesh 302 (e.g., its porous channel) may include a gas diffusion layer having a cathode catalyst material. BPP307 (e.g., an electrode plate) may be a cathode-side electrode plate. An electrode fluid inlet adjacent to the electrically conductive, compressible porous mesh 302 on one side outside the plane of the paper may be a cathode-side fluid inlet, and an electrode fluid outlet adjacent to the electrically conductive, compressible porous mesh 302 on the other side outside the plane of the paper may be a cathode-side fluid outlet. Of the above MEA301, the electrode catalyst located on the side facing the electrically conductive, compressible porous mesh 302 may be a cathode catalyst. BPP306 (e.g., an electrode plate) may be an anode-side electrode plate. Of the above MEA301, the catalyst located on the side facing the electrically conductive, compressible porous mesh 303 (e.g., its porous channel) may be an anode catalyst. An electrode fluid inlet adjacent to the electrically conductive, compressible porous mesh 303 on one side outside the plane of the paper may be an anode-side fluid inlet, and an electrode fluid outlet adjacent to the electrically conductive, compressible porous mesh 303 on the other side outside the plane of the paper may be an anode-side fluid outlet. The MEA 301 may include an ion-conductive separator placed between the anode catalyst and the cathode catalyst. The electrically conductive, compressible porous mesh 303 may be positioned to allow the flow of anode-side fluid from the anode-side fluid inlet to the anode-side fluid outlet.

[0045] The cell can transition from an uncompressed state to a compressed state by a force applied toward the center of the cell by a first compression plate and a second compression plate that is fastened to or otherwise pressed toward the first compression plate. Thus, the electrically conductive, compressible porous mesh can be compressed by the first and second compression plates. In the illustrated example, the channels on both sides of the cell are formed by the electrically conductive, compressible porous mesh; however, in some embodiments, only one side may utilize such a channel.

[0046] In Figure 3, the MEA 301 is sandwiched between two GDLs extending from the left to the right side of the cross-section, these GDLs not shown individually in the figure. The electrically conductive, compressible porous mesh 302 forms a porous channel in contact with one of the two GDLs. The electrically conductive, compressible porous mesh 303 forms a porous channel in contact with the other of the two GDLs. In the uncompressed state, cell 300 is not compressed. In the compressed state, cell 310 is compressed by pressure applied towards the center of the cell via BPP 307 and BPP 306. In the compressed state configuration, the electrically conductive, compressible porous mesh 302 may be a compressed electrically conductive mesh, which can provide a fluid path from the electrode fluid inlet to the electrode fluid outlet of the cell through the compressed electrically conductive mesh. The fluid flow flows towards the back of the page in Figure 3. In the illustrated example, BPP307 and BPP306 are flat plates that do not contain any channels or other patterned structures. Therefore, the cell is easier to manufacture compared to a cell that uses bipolar plates that have structures for forming channels or for housing molded gasket material.

[0047] In alternative embodiments, the surface of the plate may include channels and complex flow path patterns. Any of these flow path patterns can be used in combination with multiple electrically conductive, compressible mesh pieces formed to conform to the flow path pattern, or with a single molded, electrically conductive, compressible mesh piece formed to conform to the flow path pattern. Any of these flow path patterns can be used with a loose gasket, wherein the gasket's cutouts include the flow path pattern, so that the gasket includes the negative shape of the flow path pattern. In certain embodiments, the loose gasket may be replaced with a gasket fixed to the edge of the plate and having the pattern disclosed herein.

[0048] As shown in the figure, the cell is compressed to a certain degree indicated as "cell compression," the porous channel is compressed by the distance of the "cell compression," and the gasket is compressed by a distance less than the distance of the "cell compression." By designing the porous channel mesh to be taller than the gasket in the uncompressed cell, the amount of gasket compression can be defined as the degree of cell compression. Such a configuration is desirable because compressing the gasket to a desired degree defines the airtightness of the cell and provides all the advantages described above. As shown in the figure, the electrically conductive, compressible porous mesh 302 extends from the MEA 301 to the BPP 307, thereby providing a conductive path between the bipolar plate (BPP) and the electrode of the MEA 301. By setting the initial thickness of the porous channel to be greater than that of the gasket material, it is also ensured that the contact between the plate and the porous channel is sufficiently good for the conductive path. In certain embodiments of the present invention, the material forming the porous channel, such as the compressed electrically conductive mesh, can be compressed to a range of 20% to 40% of its uncompressed volume. In some embodiments, this degree of compression ensures that the porous channel works in cooperation with the gasket to exhibit the desired electrical conductivity and stability, while at the same time ensuring that the pores of the porous channel do not collapse to the extent that they cannot easily allow fluid flow through the mesh.

[0049] Figure 4 shows an electrode plate 400 in an electrolytic cell according to a particular embodiment of the invention disclosed herein, and the same electrode plate 400 with a conductive mesh 410 placed on it. The illustrated electrolytic cell includes a compression plate 401 which may be used to compress the electrolytic cell in combination with another compression plate located on the opposite side of the cell. As shown, the compression plate 401 includes a pair of tunnels 402 which connect the active region of the cell to the inter-cell fluid connection of the stack. The active region of the cell is sandwiched between an electrode fluid inlet 403 and an electrode fluid outlet 404. Fluid that has reached the active region may flow through the conductive mesh 410 to the opposite side of the cell and then be removed through a tunnel located on the opposite side of the compression plate 401, which is not visible due to the angle of the figure but roughly corresponds to the pair of tunnels 402.

[0050] Figure 5 shows an electrode plate (e.g., electrode plate 400) in an electrolytic cell with a gasket 500 placed on the cell, according to a particular embodiment of the invention disclosed herein, and the same electrode plate with an MEA 510 placed on the gasket 500. As shown, the gasket 500 prevents fluid leakage between the compression plate and the MEA 510. The gasket 500 includes a notch 501 in the active region, which allows the fluid to flow unimpeded through the porous channel and in contact with the MEA 510. However, as shown, the MEA 510 includes a central region 511 having the electrodes and catalyst of the apparatus and extends outside the active region and fluid channel of the compression plate to prevent leakage around the channel or outside the cell.

[0051] The electrically conductive, compressible porous mesh according to this disclosure can take various forms. The electrically conductive, compressible porous mesh may be stainless steel (in particular, but not limited to 316L), titanium, graphite, aluminum, nickel, nickel-chromium alloys, or any conductive material, and the plate may be provided with one or more surface coatings (e.g., those containing Pt, Au, Ti, Cr, Nb, Ni, or Fe). The material may form a conductive mesh or an electrically conductive porous foam. The mesh may form a structured grid or an amorphous foam. The electrically conductive, compressible porous mesh may include a coating. The coating may be gold, nickel, or platinum. Some materials may be selected to suit a particular environment. For example, in a carbon oxide electrolytic apparatus, nickel may be selected as an anode material for a conductive mesh or gas diffusion layer. Nickel may function on its own as a suitable catalyst for the anode in the reaction, or it may be coated with Ir as an additional catalyst. However, nickel should not be used in certain reactions at the cathode, and nickel present on or near the catalyst surface during carbon monoxide electrolysis should be avoided because it can produce toxic nickel carbonyl compounds.

[0052] A channel formed by an electrically conductive, compressible porous mesh in accordance with this disclosure may be referred to as a porous channel. The porous channel may be pressed onto a plate of an electrolytic cell and held in place by compression of the cell. Alternatively, the porous channel may be bonded to a plate, such as by welding the porous channel to the plate. The porous channel may be bonded to the plate along the sides of the channel pattern (e.g., the periphery of the channel pattern) or continuously across the entire channel pattern. The porous channel may be formed from an electrically conductive mesh or an electrically conductive porous foam.

[0053] The porous channel described above may be designed according to specific design constraints. The material, pore size, and compressibility of the porous channel may be selected to enable uniform compression of the channel together with the gasket system, formation of the channel at low fluid pressure, and formation of ohmic connections traversing the channel with sufficiently low resistivity. Generally, the pores in the channel may be set to dimensions that allow the electrolyte, reactants, or products of the electrolytic cell to flow sufficiently through the channel. In certain embodiments, the pore diameter may be 0.5 mm. In certain embodiments, the pore diameter may be in the range of 0.1 to 2 mm. Increasing the pore size may result in a decrease in the conductivity of the porous channel and, consequently, an increase in the resistivity of the electrolytic cell. On the other hand, decreasing the pore size may lead to an increase in the pressure required to push the reactants or electrolyte fluid through the porous channel, which may degrade the performance of the device through non-uniformity of the flow field and increased leakage and other problems due to the increased pressure required for the system to function. As used herein, “pore size” refers to the average size of the volume enclosed by the conductive material. Generally, the pores in a porous channel are open pores that allow fluid communication between the fluid inlet, fluid outlet, and MEA. In terms of volume ratio, the amount of conductive material may be relatively small compared to the volume of the open pores, but the dimensions of the pore diameter can be measured by evaluating the shape of the skeletal structure of the conductive material that at least partially encloses the open volume.

[0054] Many variations are possible in the structure and materials of the porous channel depending on the reactants and products of the electrolytic device. As mentioned above, the porous channel mesh may be an electrically conductive foam or an electrically conductive structured mesh. Figure 6 shows several examples of conductive mesh configurations and their associated mounting structures according to a particular embodiment of the present invention. Note that the examples shown in Figure 6 are not intended to show the specific shape or arrangement of pores, but rather to illustrate the relative size and positional relationships, as well as configurations including one or more layers that may be present, and to illustrate various embodiments of the mesh structure. Conductive mesh structure 610 is an example of a part of mesh 612 that is in contact with electrode 600. Conductive mesh structure 610 may be part of porous mesh 302 or porous mesh 303 in Figure 3. Electrode 600 may be a GDL electrode corresponding to the upper surface of MEA 301, or a porous electrode that may correspond to the aqueous anode side of MEA 301. Conductive mesh 612 shows a number of porous cells of substantially the same size. The mesh 612 has a distinctive internal structure and can be formed using, for example, a woven fiber mesh made of materials such as expanded metal, a flat metal grid, or metal or carbon fiber.

[0055] Grid 616 is an example of a flat grid, and a top view of a single stackable layer is shown. This grid can be stacked to form a mesh, for example, individual horizontal layers 614 and 615 may have a pattern like grid 616. Grid 616 shows a square pattern, but the holes in the grid can have any shape or size. In some modifications, different patterns may be used for consecutive layers. Consecutive layers, such as layers 614 and 615, may be arranged so that their holes are aligned with each other, or they may be translated so that the hole structures only partially overlap. Each layer may be aligned in the rotational direction, or alternatively, they may be rotated so that the patterns do not overlap. Structures in which multiple layers do not precisely overlap may promote fluid mixing by promoting turbulence in the fluid passing through the mesh. Furthermore, some meshes, such as expanded metal, may have less flow resistance in one direction compared to other directions. Even layers with similar pore sizes can increase turbulence rather than laminar flow by rotating the layers. Another example is woven mesh 617. Individual fibers, consisting of metal fibers, carbon fibers, or other materials, can be woven together to form a layered structure. By selecting various sizes of fibers 618 and their spacing, the effective pore size in the layered stack of conductive mesh 612 can be selected. As in the example above, layers 614 and 615 can be grids (such as woven net 617), and similar deformations are possible with respect to translation and rotation of each constituent layer. In certain embodiments, layers can be joined together by welding or sintering. Alternatively, layers may be left unjoined, but reliable electrical contact can be obtained when the entire structure is assembled and compressed.

[0056] As another example, the conductive mesh structure 620 includes two or more structured mesh layers positioned in contact with the electrode 626. Mesh 622 may have a certain average pore size, and mesh 624 may have a different pore size. Although only two mesh layers are shown, multiple different mesh layers may be provided. In certain embodiments, the pore size of the mesh layers may decrease monotonically from the upper side of the mesh layer (in this example, the upper surface of mesh 622 facing the electrode plate) toward the lower layer connected to the electrode 626. The structured mesh layers may be composed of substantially the same material or of different materials. Each mesh layer, such as mesh 622, may have a structure similar to the structure described for mesh 612 above. Meshes with multiple pore sizes may have several advantages over meshes with a single pore size. Larger pore sizes near the electrode plate inlet allow for freer flow of incoming reactants and outgoing products. Furthermore, one or more additional layers with decreasing pore sizes may introduce turbulence into the flow.

[0057] The conductive mesh structure 630 is similar to the mesh structure 610, but differs in that the mesh 632 has an irregular or amorphous structure. In this case, the average pore size may have a size distribution, while having a generally similar size throughout the mesh 632. The mesh 632 may be a metal foam or a foam made of other materials such as expanded graphite foam. The mesh 632 may also include a polymer structure in which graphite is mixed into a monomer mixture before foam formation. Furthermore, the mesh may be formed from carbon powder, and the gaps between the powder particles may function as pores throughout the structure.

[0058] The conductive mesh structure 640 is similar to the mesh structure 620 in that it has multiple layers with different pore sizes, but like mesh 632, meshes 642 and 644 are irregular or amorphous structures and may include the aforementioned foams or other structures. Although the mesh structure 640 shows two meshes 642 and 644 (e.g., mesh layers), multiple mesh layers may be provided. In some cases, an irregular mesh structure may be formed, for example, by joining two metal foams having different pore sizes (and possibly different compositions). The metal foams may be formed using known techniques such as gas injection into metal powder or metallization of polymer foams. In other cases, the entire structure 640 may be metallized integrally, for example, by arranging multiple layers of polymer foam, such as polyethylene, in contact with each other and then metallizing them integrally in a manner similar to that used for single-layer polymer foams. In certain embodiments, the amorphous conductive mesh may be formed to have a more continuous change in pore size. The polymer foam may be formed to have a gradient of pore size along a specific axis within the foam. A single-layer foam with a generally continuous pore size gradient can be similarly metallized to form a structure in which the pore size gradually decreases along the depth direction from the electrode plate toward the MEA.

[0059] In certain embodiments, the gas diffusion layer electrode may be integrated with the conductive mesh layer and positioned to be in direct contact with the film. An example of a common GDL electrode on the cathode side is a hydrophobic carbon fiber paper whose surface is treated with a copper layer to produce copper nanoparticles. These copper nanoparticles have a high surface area and function as a cathode catalyst when in contact with the film. Furthermore, the carbon paper may act as a barrier to prevent some chemical species diffusing through the film from coming into contact with other parts of the conductive mesh. For example, stainless steel can be a suitable mesh material, but if some reactive chemical species migrate to the stainless steel layer, it may cause undesirable side reactions. Instead of a separate layer formed on carbon, carbon nanoparticles may be formed directly on the underside of the mesh. In some cases, a copper layer may be formed, for example, by electroplating, vapor deposition, or other methods, and then copper nanoparticles may be formed on the surface. In some embodiments, a copper foam layer may also be attached to the underside of the conductive mesh (by welding, sintering, or compression) before being functionalized with copper nanoparticles.

[0060] Conductive mesh has been used as an alternative to patterned channels on electrode plates in certain applications where the material types at the anode and cathode are balanced. For example, in a proton-exchange membrane water electrolyzer (PEMWE), aqueous fluid is present on both the anode and cathode sides of the membrane. Another example is a hydrogen fuel cell using a PEM, where gas is supplied to both the anode and cathode. In such applications, the water produced by the reaction is rapidly wicked away from the membrane using a conductive mesh, and the conductive mesh can be used on both sides to facilitate mixing and transport of the reactants. However, these structures have not been conventionally used in carbon oxide electrolyzers, or in electrolyzers where one side (e.g., the cathode) uses a gas-supplied GDL and the other side (e.g., the anode) uses an aqueous fluid or other liquid flow on the membrane. This is because various pressure differences exist that are necessary for the electrochemical cell to operate functionally and efficiently.

[0061] For example, in carbon oxide electrolytic devices, a pressure difference can be used between the cathode and anode sides of a membrane to prevent liquid from leaking into the cathode region. In some cases, the pressure difference can be 800 mbar or more, and the high pressure on the cathode side allows the electrolytic device to operate with little to no water leakage onto the cathode catalyst. The presence of water on the cathode side can generate hydrogen gas, which is often undesirable for many reaction products such as ethylene and reduces the efficiency of the cell. In some configurations, by precisely adjusting the pressure difference between the two sides, the location of the liquid / gas interface can be controlled to be very close to the cathode catalyst in order to obtain an optimal conversion rate while minimizing water leakage. Another type of pressure in these systems is the mechanical pressure applied to the cathode electrode. The pressure on the liquid anode side is necessary to prevent leakage and to bring the components into contact, but the pressure tolerance on this side is relatively wide because the aqueous solvent promotes ion transport of reactants to the anode catalyst. On the other hand, on the cathode side, since the flow is entirely gaseous, it is even more important that the cathode catalyst is in close contact with the separator film, especially when the liquid interface only reaches the position of the cathode catalyst. To achieve this close contact across the entire surface, the pressure applied to the gas diffusion layer can reach up to 1 MPa.

[0062] Figure 7 includes two plots showing the fluid resistance of two compressed electrically conductive meshes according to a particular embodiment of the invention disclosed herein. As previously mentioned, the size of the pores can affect both the pressure required to push reactants or electrolytes through the channel and the electrical conductivity of the porous channel. Furthermore, the height of the mesh in a direction perpendicular to the direction of fluid flow can similarly affect both of these elements, i.e., an increase in height can result in a decrease in resistance to fluid flow and an increase in electrical resistance. In these figures, the fluid resistance is Δ p =K × Q m It is calculated using the formula, where Q m Δ is the mass flow rate of carbon monoxide supplied to the electrolytic device.p This represents the pressure drop on the anodic liquid side. As shown in the figure, for a thin mesh with a thickness of 0.2 mm and a width and length of 7.1 mm, the fluid resistance K is 0.1454 bar / (grams / min), and for a thick mesh with a thickness of 0.9 mm and a width and length of 7.1 mm, the fluid resistance K is 0.0219 bar / (grams / min). Both meshes are subjected to a compression of 1 MPa. The electrical resistivity of the thin mesh is 2,500 mΩ·cm. 2 The electrical resistivity of the thick mesh mentioned above is 150 mΩ·cm. 2 The porous channel disclosed herein has a capacitance of 5,000 mΩ·cm. 2 Even at resistivity values ​​reaching 10 mΩ·cm, sufficient functionality can be provided for the electrolytic cell. In this range, fluid resistance is generally very low, and operating pressure is not a problem. The porous channel disclosed herein has a resistivity of 10 mΩ·cm. 2 Even at resistivity values ​​lower than or equal to that, the electrolytic cell may still function adequately. However, at such low values, it becomes difficult to ensure the operating pressure necessary to ensure efficient distribution of reactants or electrolytes through the flow path.

[0063] In typical applications, patterned channels on electrode plates limit the overall gas flow rate, particularly by providing sufficient back pressure to the generated gas to maintain a high pressure difference between the cathode and anode. In contrast, open porous meshes, such as those described herein, allow for greater gas flow away from the membrane closer to the electrode plate, making it more difficult to control the cathode-side pressure. These meshes act as an additional gas diffusion layer to the electrode, and the smaller pore size near the electrode promotes mixing to bring more reactants into contact with the catalyst. However, it was also thought that this could allow for excessive gas outflow, potentially reducing the overall reaction efficiency and increasing undesirable byproducts.

[0064] However, surprisingly, the opposite has been shown to be true. Traditionally, the main advantages of conductive mesh compared to standard channels used in gas-phase electrodes were thought to be cost reduction and ease of manufacture. However, by carefully selecting the pore size of the mesh, it is possible to ensure sufficient flow of the reaction gas fluid and achieve high conversion efficiency. Back pressure on the cathode side can be controlled to maintain a positive pressure difference by controlling the reactant flow rates on both the anode and cathode sides, and by externally restricting the flow of gaseous products at the outlet side of the cathode-side electrode interface, for example, using a back pressure valve. Furthermore, by monitoring the pressure at the outlets on both the cathode and anode sides, the pressure difference between the cathode and anode sides can be actively controlled to minimize the impact of fluctuations in inflow flow rates on the performance of the electrolytic device. Contrary to expectations, conductive mesh channels exhibit improved characteristics compared to standard channels, as shown in the following figure.

[0065] Figure 8 shows two plots comparing a configuration using a conductive mesh with a cell containing only a standard patterned channel. The upper plot shows the pressure drop with respect to the mass flow rate of the reactants at the cathode, and the lower plot shows the pressure drop with respect to the mass flow rate of the reactants at the anode. Both cells use similar membranes and cell areas. Although these results are affected by mesh height, pore size, and other parameters, in this configuration, the reaction flow rate at a given inflow pressure is higher in the conductive mesh cell, as indicated by the smaller slope of the pressure drop. Lower pressure required to achieve the same reactant flow rate is advantageous because large pressure fluctuations can cause changes in the electrical and mechanical contact between the catalyst and the membrane.

[0066] Figure 9 shows two plots comparing the same two cells shown in Figure 8. The upper plot shows voltage (V) against time (minutes). Trace 910 shows the electrochemical voltage driving the cell with a standard channel, and trace 912 shows the time variation of the same voltage in the cell with a conductive mesh. Throughout the entire period until the first cell fails, the conductive mesh cell consistently has a lower voltage. The lower voltage suggests a higher Faraday efficiency (FE) of the cell and is considered an improvement. The lower plots show the production of ethylene (C2H4) and hydrogen gas (H2) in both cells. The production of ethylene and hydrogen gas in the standard channel cell is shown in traces 920 and 921, respectively. In this configuration, separation is observed initially, but over time, the selectivity between ethylene and hydrogen decreases and eventually becomes similar. In contrast, the production of ethylene and hydrogen gas in the conductive mesh cell is shown in traces 932 and 933, respectively. In this case, selectivity is significantly improved throughout the entire operating period, and furthermore, the desired product, ethylene, is produced at a higher rate than in the other cell.

[0067] One possible reason for these improved results is that the conductive mesh applies uniform pressure to the electrode catalyst on the gas phase side, i.e., the cathode side in this example. Electrode plates with patterned channels formed on their surface by etching or other methods have numerous open spaces through which gaseous reactants and products enter and exit. In these open spaces, the electrode plate can apply little to no pressure to the GDL electrode. On the other hand, in cells with a conductive mesh, the flat electrode plate can apply uniform pressure across the entire surface of the conductive mesh, and furthermore, the mesh itself distributes its force uniformly across the entire catalyst, ensuring stable contact between the catalyst and the film. This is the most likely reason why the voltage required for the reaction is reduced in conductive mesh cells.

[0068] Figure 10 shows a flowchart 1000 of a method for forming an electrolytic cell comprising a fluid distribution system according to a particular embodiment of the invention disclosed herein. Flowchart 1000 includes step 1001 of mounting an electrode plate to a first cell compression plate. By performing this step, the electrode plate and the cell compression plate form an electrode fluid inlet and an electrode fluid outlet. The fluid inlet may be formed in part by the electrode plate and in part by the compression plate. Flowchart 1000 further proceeds to step 1002 of placing an electrically conductive mesh on the electrode plate. The electrically conductive mesh may be a compressible electrically conductive mesh and is first placed on the active region of the electrode plate. Flowchart 1000 further proceeds to step 1003 of placing an electrode catalyst on the electrically conductive mesh. The electrode catalyst may be part of an MEA placed on the electrically conductive mesh. The electrode catalyst may be placed on an electrode. The electrode catalyst may be in contact with the electrically conductive mesh. The above-mentioned electrically conductive mesh may have any of the properties described above with respect to the compressible electrically conductive material described herein.

[0069] Flowchart 1000 further proceeds to step 1004, in which the electrically conductive mesh is compressed to a compressed electrically conductive mesh by compression using a first cell compression plate. By performing this step, the compressed electrically conductive mesh can be arranged to allow fluid to flow through it from the electrode fluid inlet to the electrode fluid outlet. By performing this step, the compressed electrically conductive mesh can be compressed to a range of 20% to 40% of the volume of the electrically conductive mesh.

[0070] In certain embodiments, the electrode catalyst may be a cathode catalyst. In certain embodiments, the electrode catalyst may be an anode catalyst. In certain embodiments, the fluid flow may be a flow of gaseous cathode-side feedstock. In certain embodiments, the fluid flow may be a flow of aqueous anode-side feedstock.

[0071] Flowchart 1000 further includes step 1005 of forming a gasket having notches shaped to correspond to the compressed electrically conductive mesh, the electrode fluid inlet, and the electrode fluid outlet. The gasket may be a loose gasket and is compressed together with the compressed electrically conductive mesh in step 1004 to form a seal for the electrolytic cell. The shape of the notches may allow reactants or electrolytes to flow from the active region of the cell to the periphery of the cell and into contact with the electrodes of the cell.

[0072] Flowchart 1000 further includes step 1006 of fastening a second compression plate to the first compression plate. The compression plate and the second compression plate may be used in step 1004, in which compression is performed using the compression plate and the second compression plate. The cell can be compressed by pressing the two plates toward each other. The second compression plate may be cell-specific, and the cell may have its own independent compression plate. Alternatively, the second compression plate may be shared with other cells or with the entire stack which includes the cell as part. The compression plates can be compressed toward each other using fastening means such as screws or rivets. The compression plates can be compressed toward each other using a molding process or adhesive which is formed or applied under external pressure.

[0073] Flowchart 1000 further includes step 1007 of forming a coating on the electrically conductive mesh. This step may be performed before the electrically conductive mesh is placed in the electrolytic cell and may be performed to reduce the electrical resistance of the mesh. The coating may be any material having lower electrical resistance than the main material of the mesh, and such material may include gold or platinum.

[0074] Figure 11 shows a portion of an electrolytic cell 1100 according to a particular embodiment of the invention disclosed herein. In this example, cell 1100 is essentially similar to the embodiment shown in Figure 4, except that cell 1100 can be implemented as a modular configuration that is not fluidly connected in a stack. That is, instead of bipolar plates, unipolar plates are used on the upper and lower sides. Figure 11 is shown as an exploded view, and each component is assembleable. In a particular embodiment, a flat metal plate 1110, for example made of stainless steel, may be used to cover the upper cathode side. In a particular embodiment, a flat metal plate 1130, for example made of nickel, may be used to cover the lower anode side. Between these, a cell frame 1120 can be positioned to hold a MEA containing two compressible meshes on both sides. The cell frame may have an opening 1116 that holds the membrane. Compressible meshes may be positioned in recesses 1115 above and below the membrane. Although not shown, a similar recess may be provided on the underside of the cell frame 1120 for a compressible mesh on the anode side. The cell frame 1120 may be made of plastic, metal, or other material. Fluid inlets may be configured to connect to various holes (not shown) provided inside the cell frame 1120, for example, in the recess 1115 on the cathode side or in a similar recess on the anode side. Fluid inlets 1112 and 1113 may be connected to the cathode side, and fluid inlet 1114 may be connected to the anode side. Fluid outlets are provided on the rear side of the cell frame 1120 and are not shown, but are configured similarly to the fluid inlets. Gaskets may be provided on the flat surface between the plate 1110 and the cell frame 1120, or in the grooves, and similarly between the plate 1130 and the cell frame 1120. The entire assembly can be fastened together by screws or other fasteners to apply pressure to the internal components and prevent leakage.

[0075] Figure 12 shows a portion of an electrolytic cell 1200 according to a particular embodiment of the invention disclosed herein. In this example, cell 1200 is essentially similar to cell 1100 shown in Figure 11, and cell 1200 can be implemented as a modular configuration that is not fluidically connected in a stack. Also, instead of a bipolar plate, a monopolar plate is used on the upper and lower sides. Figure 12 is shown as an exploded view, and each component is assembleable. Cell 1200 does not include a cell frame and instead comprises two metal plates 1210 and 1220. The cathode plate 1210 has a fluid inlet 1212 on one side edge and a fluid outlet corresponding to the other side edge. Similarly, the anode plate 1220 may have a fluid inlet 1222 on one side edge and a fluid outlet corresponding to the other side edge. In this example, the cathode and anode fluid inlets are located on different sides to facilitate external fluid tubes or other connections, but they may be located on the same side. Each plate may have a recess 1224 (not a through hole), which, during assembly, forms a space for accommodating a compressible mesh for the cathode, a membrane, and a compressible mesh for the anode. A gasket may be provided between the two plates. As an example, the cathode plate is made of stainless steel and the anode plate is made of nickel.

[0076] While this specification describes in detail specific embodiments of the present invention, it will be understood that those skilled in the art will readily conceive of modifications, variations, and equivalents to these embodiments by understanding the foregoing. For example, while examples of electrolytic devices with MEAs are used throughout this disclosure, the methods disclosed herein are also applicable to other electrolytic cell configurations that generally use a separator between the two halves of the cell. Another example is the example of a carbon monoxide (CO) electrolytic device used throughout this disclosure, but the methods disclosed herein are also applicable to other electrolytic devices, including carbon dioxide (CO2) electrolytic devices, and more generally to electrolytic devices and fuel cells. These and other modifications and variations to the present invention can be carried out by those skilled in the art without departing from the scope of the present invention, which is more specifically defined in the appended claims.

Claims

1. Carbon oxide electrolytic cells (200, 1100, 1200), Electrode plate (400) and, The cathode region and A carbon oxide reaction gas that functions as a reducing substrate in the cathode region, Cathode side fluid inlet, Cathode side fluid outlet, Anode region and, The liquid oxidizing substrate in the anode region, A compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644) comprising (i) electrically contacting the electrode plate (400) and (ii) providing a fluid path for the carbon oxide reaction gas from the cathode side fluid inlet to the cathode side fluid outlet through the compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644) Carbon oxide electrolytic cell.

2. A carbon oxide electrolytic cell (200, 1100, 1200) according to claim 1, moreover, The second electrode plate (400) and The aqueous anodic solution in the aforementioned anode region, Anode side fluid inlet, Anode side fluid outlet, A second compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644) comprising (i) contacting the second electrode plate (400) and (ii) providing a second fluid path for the aqueous anodeliquid from the anode-side fluid inlet to the anode-side fluid outlet through the second compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644), Carbon oxide electrolytic cell.

3. The electrolytic cell (200, 1100, 1200) according to claim 2, The second compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644) is formed of nickel. Electrolytic cell.

4. The electrolytic cell (200, 1100, 1200) according to claim 2, The second compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644) is a foam or structured mesh (612, 622, 624, 632, 642, 644). Electrolytic cell.

5. The electrolytic cell (200, 1100, 1200) according to claim 1, The pressure in the cathode region is higher than the pressure in the anode region. Electrolytic cell.

6. The electrolytic cell (200, 1100, 1200) according to claim 1, The electrolytic cells (200, 1100, 1200) are part of the electrolytic stack (100), The electrolytic stack (100) further The first compression plate (401) and A second compression plate (401) fastened to the first compression plate (401) to compress the electrolytic cells (200, 1100, 1200), Equipped with, The compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644) is compressed by the first compression plate (401) and the second compression plate (401), The compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644) is uniformly compressed across its entire surface. Electrolytic cell.

7. The electrolytic cell (200, 1100, 1200) according to claim 1, The compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644) is a metal foam. Electrolytic cell.

8. The electrolytic cell (200, 1100, 1200) according to claim 1, The compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644) is a structured metal. Electrolytic cell.

9. The electrolytic cell (200, 1100, 1200) according to claim 8, Multiple layers (614, 615) of the compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644) are welded to each other. Electrolytic cell.

10. The electrolytic cell (200, 1100, 1200) according to claim 8, Multiple layers (614, 615) of the compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644) are sintered together. Electrolytic cell.

11. The electrolytic cell (200, 1100, 1200) according to claim 1, Multiple layers (614, 615) of the compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644) are electrically connected by the mechanical pressure applied to the multiple layers (614, 615). Electrolytic cell.

12. The electrolytic cell (200, 1100, 1200) according to claim 1, The compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644) is a carbon-doped polymer. The carbon is in the form of expanded graphite foam or carbon powder. Electrolytic cell.

13. The electrolytic cell (200, 1100, 1200) according to claim 1, The compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644) contains carbon in the form of carbon fiber cloth or carbon powder. Electrolytic cell.

14. The electrolytic cell (200, 1100, 1200) according to claim 1, The pore diameters throughout the compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644) are substantially the same. Electrolytic cell.

15. The electrolytic cell (200, 1100, 1200) according to claim 1, The pore size throughout the compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644) changes in the depth direction away from the electrode plate (400). Electrolytic cell.

16. The electrolytic cell (200, 1100, 1200) according to claim 15, The average pore size in the compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644) decreases as the distance from the electrode plate (400) increases. Electrolytic cell.

17. Carbon oxide electrolytic cells (200, 1100, 1200), Electrode plate (400) and, The cathode region and A carbon oxide reaction gas that functions as a reducing substrate in the cathode region, Cathode side fluid inlet, Cathode side fluid outlet, membrane and Compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644) comprising (i) steel, (ii) electrically in contact with the electrode plate (400), and (iii) providing a fluid path for the carbon oxide reaction gas from the cathode-side fluid inlet to the cathode-side fluid outlet through the compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644), The system comprises a separate carbon-based gas diffusion layer, which supports a catalyst, located between the compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644) and the film. Carbon oxide electrolytic cell.

18. A carbon oxide electrolytic cell (200, 1100, 1200) according to claim 17, moreover, The second electrode plate (400) and Anode region and, The aqueous anodic solution in the aforementioned anode region, Anode side fluid inlet, Anode side fluid outlet, A second compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644) comprising (i) contacting the second electrode plate (400) and (ii) providing a second fluid path for the aqueous anodeliquid from the anode-side fluid inlet to the anode-side fluid outlet through the second compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644), Carbon oxide electrolytic cell.

19. The electrolytic cell (200, 1100, 1200) according to claim 18, The second compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644) is formed of nickel. Electrolytic cell.

20. The electrolytic cell (200, 1100, 1200) according to claim 18, The second compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644) is a foam or structured metal mesh (612, 622, 624, 632). Electrolytic cell.

21. The electrolytic cell (200, 1100, 1200) according to claim 17, Furthermore, it is equipped with an anode region, The pressure in the cathode region is higher than the pressure in the anode region. Electrolytic cell.

22. The electrolytic cell (200, 1100, 1200) according to claim 17, The electrolytic cells (200, 1100, 1200) are part of the electrolytic stack (100), The electrolytic stack (100) further The first compression plate (401) and A second compression plate (401) fastened to the first compression plate (401) to compress the electrolytic cells (200, 1100, 1200), Equipped with, The compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644) is compressed by the first compression plate (401) and the second compression plate (401), The compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644) is uniformly compressed across its entire surface. Electrolytic cell.

23. The electrolytic cell (200, 1100, 1200) according to claim 17, The compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644) is a metal foam. Electrolytic cell.

24. The electrolytic cell (200, 1100, 1200) according to claim 17, The compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644) is a structured metal. Electrolytic cell.

25. The electrolytic cell (200, 1100, 1200) according to claim 17, Multiple layers (614, 615) of the compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644) are welded to each other. Electrolytic cell.

26. The electrolytic cell (200, 1100, 1200) according to claim 17, Multiple layers (614, 615) of the compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644) are sintered together. Electrolytic cell.

27. The electrolytic cell (200, 1100, 1200) according to claim 17, Multiple layers (614, 615) of the compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644) are electrically connected by the mechanical pressure applied to the multiple layers (614, 615). Electrolytic cell.

28. The electrolytic cell (200, 1100, 1200) according to claim 17, The pore diameters throughout the compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644) are substantially the same. Electrolytic cell.

29. The electrolytic cell (200, 1100, 1200) according to claim 17, The pore size throughout the compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644) changes in the depth direction away from the electrode plate (400). Electrolytic cell.

30. A method (1000) for forming an electrolytic cell (200, 1100, 1200), Step (1001) involves attaching the electrode plate (400) to the first compression plate (401), thereby so that the electrode plate (400) and the first compression plate (401) form an electrode fluid inlet and an electrode fluid outlet. Step (1002) of arranging electrically conductive meshes (410, 612, 622, 624, 632, 642, 644) on the electrode plate (400), The steps include (1003) arranging electrode catalysts on the electrically conductive mesh (410, 612, 622, 624, 632, 642, 644), Step (1004) of compressing the electrically conductive mesh (410, 612, 622, 624, 632, 642, 644) using the first compression plate (401) to create compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644), thereby arranging the compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644) so ​​that fluid can flow through the compressed electrically conductive mesh (410, 612, 622, 624, 632, 642, 644) from the electrode fluid inlet to the electrode fluid outlet, A method for providing this.

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