A flow field plate, an electrolysis cell, an electrolytic device and methods for preparing the electrode, the electrolysis cell and the electrolytic device

Abstract

A flow field plate comprising a conductive insert comprising a flow channel pattern and a frame plate comprising on one or both sides a pocket configured to receive the insert. An electrolysis cell comprising a membrane electrode assembly comprising an anode combined with the flow field plate, a cathode combined with the flow field plate, and an ion exchange membrane between the anode and the cathode, wherein one or more of the flow field plates comprises a conductive insert comprising a flow channel pattern and a frame plate comprising on one or both sides a pocket configured to receive the insert. An electrolytic device comprising one or more of the flow field plates or one or more of the electrolysis cells. A method for preparing a flow field plate, an electrolysis cell and an electrolytic device.

Description

[0001] A flow field plate, an electrolysis cell, an electrolytic device and methods for preparing the electrode, the electrolysis cell and the electrolytic device

[0002] Field of the application

[0003] The present application relates to a flow field plate, to an electrolysis cell comprising the flow field plate, and to an electrolytic device comprising the flow field plate or the electrolysis cell. The present application also relates to a method for preparing the flow field plate, to a method for preparing the electrolysis cell and to a method for preparing the electrolytic device.

[0004] Background

[0005] A Membrane Electrode Assembly (MEA) usually comprises a polymeric exchange membrane (PEM) sandwiched between anode and cathode layers. These may comprise, or be sandwiched between, flow field plates (FFP). The FFP has several roles, for example separating gases or liquids between the half cells and neighbouring cells in a stack, providing an electronic conducting medium between the anode and cathode, providing a specific flow field design containing channels allowing even distribution of the reaction gases, providing a solid structure for the MEA, and facilitating water and heat management.

[0006] Generally, flow field plate materials are categorized into metal-based and graphitebased materials. Metal-based materials provide high electrical and thermal conductivity, low gas permeability, mechanical strength, as well as low thickness. However, in some instances, in particular with steel, they can exhibit low corrosion resistance under high currents and / or under anodic conditions. This “oxidative” corrosion can lead to increased electrical resistance (main)and to ionic leaching breaking the mechanical and chemical balance, and decreasing the hydrophobicity of the electrolyte membrane, resulting in problems in oxygen transport. Further, a highly resistive oxide layer may form on the flow field plate, which has a negative effect on electrical performance.

[0007] Other metals such as titanium plates, although more expensive, can offer high corrosion resistance. In addition, graphite-based materials provide high corrosion resistance and low density, but exhibit high gas permeability and low mechanical strength, for example brittleness, which may result in unsatisfactory processing, high weight and high cost. Also, graphite is unstable and spontaneously exfoliated with respect to chemical oxidation.

[0008] In most prior art flow field plates the channels are obtained by engraving, which makes the preparation process slow and expensive. When using expensive materials, the size of the plates and loss of material increases costs. Figure 1 shows an example of a prior art metallic flow field plate having engraved channels.

[0009] There is a need to find new types of flow field plate structures, materials and methods for preparing thereof. It is desired to provide flow field plates and devices comprising thereof, which can be manufactured with low costs and at an industrial scale to fulfil the increasing need of devices and electrodes required in electrolytic applications, such as production of hydrocarbons, carbon monoxide and other products. It is also desired to obtain devices with low cost, low weight and high mechanical and chemical durability. It is also desired to obtain devices which can be modified and / or serviced without disassembling the whole device.

[0010] Summary

[0011] With the present solution it was possible to obtain electrodes and devices utilizing the electrodes, which could overcome prior art problems. It was possible to avoid laborious, slow and expensive prior art preparation methods. It was also possible to utilize materials and structures, which were not found useful or which were not even considered in the prior art. Especially materials with low mechanical strength could be used in flow field plates.

[0012] In the present invention it was found out that a flow field plate could be implemented in modular manner, wherein a conductive insert is placed into a frame providing mechanical support. In this manner the materials and form of the insert part comprising the flow channels does not limit the structure of the electrodes or devices comprising thereof.

[0013] This enables providing new products and production methods for forming flow field plates, which are fast, simple and inexpensive and which can provide flow field plates and electrodes comprising the plates, as well as devices comprising the electrodes, which are inexpensive, mechanically stable and which can be produced at an industrial scale. This provides benefits in a broad production chain, starting from manufacture of flow field plates to manufacture and end use of devices, such as electrolyzers. The devices can be serviced, modified and / or updated simply by changing the insert parts.

[0014] The present concept can be implemented with a variety of materials, thus enabling the effects with a broad range of materials. Even further, it was found that the materials can be formed into new types of structures, and also existing materials can be used in the present flow field plates. The new structures include mesh, sintered or felt structures and the like non-continuous structures.

[0015] The present application provides a flow field plate, such as an electrically conductive flow field plate, comprising

[0016] -a conductive insert comprising a flow channel pattern, and

[0017] -a frame plate comprising a pocket configured to receive the insert on one or both sides of the frame plate.

[0018] The present application also provides an electrolysis cell comprising

[0019] -a membrane electrode assembly comprising

[0020] -an anode combined with a flow field plate, such as an electrically conductive flow field plate, for example wherein the anode is a gas diffusion anode,

[0021] -a cathode combined with a flow field plate, such as an electrically conductive flow field plate, for example wherein the cathode is a gas diffusion cathode,

[0022] -an ion exchange membrane between the anode and the cathode, wherein one or more of the flow field plates comprises -a conductive insert comprising a flow channel pattern,

[0023] -a frame plate comprising a pocket configured to receive the insert on one or both sides of the frame plate.

[0024] The present application also provides an electrolytic device comprising one or more of the electrodes or one or more of the electrolysis cells, preferably arranged as a stack.

[0025] The present application also provides a method for preparing a flow field plate, the method comprising

[0026] -providing a conductive insert comprising a flow channel pattern,

[0027] -providing a frame plate comprising a pocket configured to receive the insert on one or both sides of the frame plate, and

[0028] -inserting the conductive insert to the pocket in the frame to form a flow field plate.

[0029] The present application also provides a method for preparing an electrolysis cell, the method comprising providing one or more of the flow field plates, and assembling an electrolysis cell comprising

[0030] -a membrane electrode assembly (MEA) comprising

[0031] -an anode comprising and / or combined with the flow field plate, and / or -a cathode comprising and / or combined with the flow field plate, and -an ion exchange membrane between the anode and the cathode.

[0032] The present application also provides a method for preparing an electrolytic device, the method comprising providing two or more of the electrolysis cells comprising frame plates in the form of bipolar plates comprising a pocket configured to receive the insert on one or both sides of the frame plate, and assembling an electrolytic device comprising a stack of the electrolysis cells. The “preparing” may be or comprise “assembling” or “producing”.

[0033] The main embodiments are characterized in the independent claims. Various embodiments are disclosed in the dependent claims. The embodiments and examples recited in the claims and the specification are mutually freely combinable unless otherwise explicitly stated. Examples not in the scope of the claims are examples useful for understanding the invention.

[0034] The present frame-insert structure can provide material, cost and time savings. In the fabrication process the raw materials and the intricate flow channel pattern are the costliest items. With the present insert the structural frame plate can be designed to have a much simpler geometry, where only the edges, including sealing surfaces and bolt hole patterns, flat pockets and maybe some internal flow channels, must be machined. The material can be selected more freely and cost effectively because the frame is not in contact with the anolyte or the catholyte near the electrochemically active regions. It can also allow for other components, such as the insert, to be manufactured in other cheaper ways, such as by stamping, pressing, moulding, sintering, felt forming and / or the like methods. The only strict requirement for the frame plate material is to be mechanically strong because the frame will provide support for the insert plates when the electrolyzer cell or stack is being compressed during assembly and operation. Thus, for example, cost-effective stainless steel can be used instead of the traditional more expensive high pitting resistance steel grades. In general the frame plate may comprise or consist of metal and / or be conductive.

[0035] On the other hand, most of the material restrictions are directed to the insert plates, which must be chemically stable under anodic or cathodic reaction environments. The insert plates also must be conductive, and must be suitable for intricate manufacturing operations. However, the volume, especially the thickness, of these inserts can be only a fraction of what would be needed for a monolithic FFP, for example only about 1-4 mm versus conventional 15-20 mm. Thus, the material costs can be reduced significantly just by reducing the amount of material. This makes for example the use of expensive materials, such as titanium as anode FFP material, much more attractive solution. It is also possible to select a material which is easy to engrave as insert material. Additionally, the insert does not have to be mechanically strong, because the frame plate supporting it will take most of the bending forces. This simplifies the use of non-metallic FFP materials, such as graphite and conductive polymers. These materials are inexpensive and easy and fast to machine compared to conventional metallic options. The insert can also comprise a flexible structure, such as a mesh, felt or net of metal wires, or it can be stamped out of thin sheet of metal or formed by sintering. Thus both the insert and the frame can be prepared from different materials and in different processes, which enables optimizing both processes and parts independently.

[0036] Another saving comes from the rapid interchangeability of the insert plates. Especially in electrolyzers designed for research and development purpose, it may be of interest to have multiple flow field channel materials that can be changed for different tests. The insert type FFP makes this operation easy and fast, because the internal electrolyte fluid distribution channels are part of the frame plate. Thus, changing the inserts does not require disconnecting and reconnecting any electrolyte tubing. Additionally, even in industrial scale electrolyzer the FFP’s sustain some damage over time, such as oxidation or pitting. Use of insert plates makes the refreshment or service process fast, because only the inserts must be replaced and then cleaned afterwards.

[0037] Brief description of the figures

[0038] Figure 1 shows an example of a prior art monolithic flow field plate made of metal Figure 2 shows a general example of a single cell electrolyzer (Figure 2A), a general example of a cathode gas diffusion electrode (Figure 2B) and an exemplary setup comprising an electrolyzer connected to a power supply (2C). The legends are: 1. Cathode flow field plate, 2. Anode flow field plate, 3. Polymer Electrolyte Membrane, 4. Cathode gasket, 5. Anode gas diffusion electrode (GDE), 6. Cathode gas diffusion electrode (GDE), 7. Anode gasket, 8 / 9. Flow channels, 10. Inlet for catholyte, 11 . Outlet for anolyte, 12. Outlet for catholyte and gaseous products, 13. Inlet for anolyte, 14. Cathode electrical connection point, 15. Anode electrical connection point. 16. Membrane electrode assembly (MEA), 17. GDE composition, 18. Macrofibrous layer, 19. Microporous layer, 20. Catalyst layer, 21 . Electrolyzer, 22. Power supply, 23. Computer, and 24. Electrical wires.

[0039] Figure 3 shows a cross-section representation of bipolar plate with an anode flow-field insert or with a cathode flow-field insert. Figure 3A shows the parts as separate and Figure 3B shows an assembled bipolar flow field plate.

[0040] Figure 4 shows a cross-section representation of an end plate with an anode flow-field insert or with a cathode flow-field insert. Figure 4A shows the parts as separate and Figure 4B shows an assembled end plate.

[0041] Figure 5 shows cross-section representations of two-cell stack configurations consisting of one bipolar plate with insert and normal end plates (5A) or end plate with insert (5B).

[0042] Figure 6 shows a cross-section representation of a two-cell stack configuration with inserts and membrane electrode assemblies (MEAs).

[0043] Figure 7 shows one prototype of a modular flow field plate. Figure 7A shows the insert and the frame plate are shown separately, and Figure 7B shows the insert installed into the frame plate. The flow channels of the insert are covered by a carbon fibre paper.

[0044] Detailed description

[0045] In this disclosure, percentage values, unless specifically indicated otherwise, are based on weight (w / w, by weight, or wt%). If any numerical ranges are provided, the ranges include also the upper and lower values. In specific examples the embodiments and examples specified with the open term “comprise” may be further limited with a closed term “consisting of’.

[0046] The flow field plates in general (also called as “plates” herein) play an important role on the chemical reactions of an electrolysis cell, such as an electrolyzer cell, such as with an anion exchange membrane; a fuel cell, for example protonexchange membrane fuel cells (PEMFC); or any other applicable electrochemical cell, as the channel structure can effectively provide distribution of the agents to the electrochemical reactions. The flow field plate supplies gas, such as carbon dioxide, hydrogen (H2), and / or oxidant such as air (O2), and / r liquids such as aqueous anolyte, to the membrane electrode assembly, removes water and / or other reaction products, and collects electrons produced. The flow field plate also provides mechanical support for the cell or the stack, and to any additional parts such as porous and / or sheet like parts. The plate also enables providing a conductive medium between the anode and cathode to maintain desired operation of the cell. On the other hand, the flow field plates can effectively mitigate the bad effects of corresponding chemical reactions, such as heat, vapor, water and liquid water, since these products can be discharged outside the cell through the channels.

[0047] The present application provides a modular flow field plate, which comprises an electrically conductive insert plate, which may be an insert plate comprising an electrically conductive portion and / or an insert plate comprising or consisting of electrically conductive material. The flow field plate may be for, and may be used in, an electrode, such as an electrode of an electrolysis cell or an electrolytic device disclosed herein. The electrode may be an anode and / or a cathode. The flow field plate may be also called as a current collector plate.

[0048] The present flow field plates have a modular structure comprising an insert part as a first module, which may be also called as an insert plate, a flow field plate insert, a conductive insert and / or a combination of these terms, and a frame part as a second module, which may be also called as a frame plate, a frame, a flow field frame, a structural frame, a casing and / or a combination of these terms. Further applicable parts of the flow field plate, such as disclosed herein, may be considered as further modules.

[0049] The present insert of a flow field plate comprises or is a planar structure, and it typically has two large surfaces, wherein at least one of the large surfaces comprises one or more open faced channels, which form(s) a flow channel pattern. The insert comprises sides, which have the shortest dimension of the plate and may define the thickness of the plate, such as the highest thickness. The insert may be a continuous insert, wherein it may comprise or consist of non- porous material, such as continuous metal or polymer. The insert may be or comprise also a non-continuous insert or a part thereof, wherein it may be porous and / or comprise or consist of porous material, for example fibres, wires and / or the like parts.

[0050] Also, the frame plate comprises or is a planar or substantially planar structure, and it typically has two large surfaces. The frame plate comprises sides, which have the shortest dimension of the plate and may define the thickness of the plate, such as the highest thickness.

[0051] The frame comprises one or two pockets on one large side or on both large surfaces, which pockets are compatible with the inserts so that an insert can be inserted into the pocket. Thus, the shape of the pocket is configured to fit to the shape of the insert, preferably so that the insert is supported by the pocket and / or the frame, and preferably the insert is immobilized when inserted to the pocket. The depth of the pocket is selected so that the insert will fit to the pocket to enable forming a functional electrolytic cell when assembled. The insert is configured / designed to set completely or substantially completely inside the frame plate(s), more particularly in the pocket, in the assembled structure, preferably in such way that no edges of the insert are exposed in the assembled cell / stack, as shown in Figure 7B. The side of the insert comprising the flow channels is configured / designed to face to opposite direction from the corresponding frame plate / pocket. The side of the insert opposite to the channelled side may be flat and / or configured / designed to fit to the pocket and / or surface of the pocket. The surface of the pocket may be flat or substantially flat. The depth of the pocket may be substantially equal to the thickness of the insert. However, there should be space for any additional parts, such as membranes, catalytic and / or porous sheets and / or the like, which may be included in the final cell structure.

[0052] The pocket may comprise or be a cavity on the surface of the frame plate, such as shown in Figures 3-6, wherein elevated portions of the frame plate surround the insert on each side. i.e. on fours sides. When the frame plate is attached to another frame plate or to an end plate, for example in a stack with bipolar plates, or alternatively in a single cell, the insert is secured inside the structure. Two or more frame plates may be attached to each other, and also to end plates or cover plates with attaching means such as screws and bolts, and / or with other means such as clamps or the like. A structure is formed, such as a stack, which may be a part of an electrolyzer. If it is necessary to service the system, the structure may be disassembled to expose the inserts, which can be thus changed and / or cleaned. It is for example possible to change the inserts to another types, for example comprising different properties such as different material, thickness and / or channels.

[0053] In one example the pocket may comprise or be a cavity on the surface of the frame plate, wherein elevated portions of the frame plate surround the insert on less than four sides, such as on three sides, thus leaving one side open. Even two sides may be left open. The frame plate may be configured to allow removal of the insert from the frame plate, such as when the frame plates are attached together to form the cell or the device. For example, the insert may include one or more parts for gripping and / or removing the insert, such as a hook-like part, which can be reached with a suitable gripping means via the opening so that the insert can be removed from the structure without disassembling the structure, at least without completely disassembling the structure. In such case servicing of the structure would be simpler. The opening may be configured to be closed during use of the device, such as with a closing means, such as a hatch or an insertable plug, so that the insert is not exposed.

[0054] Flow field plates may be provided as bipolar plates and / or in bipolar configuration, which are especially useful in a stack, and / or as monopolar plates and / or in monopolar configuration, which are especially useful in an individual electrolysis cell. In applications relating to electrolytic devices and the like devices comprising two or more, such as a plurality, of electrolysis cells arranged in a stack, the flow field plates may be bipolar or monopolar plates. Bipolar plates may comprise open faced channels on both sides, i.e. on both largest surfaces.

[0055] The inserts can be selected so that one side of the frame has cathode insert and one side has anode insert, or both sides of the frame may have either anode or cathode inserts. Thus, the present insert makes switching between monopolar and bipolar easy.

[0056] In one embodiment a bipolar flow field plate comprises

[0057] -a conductive insert 32 comprising a flow channel pattern, and -a frame plate 31 comprising a pocket configured to receive the insert on one side of the frame plate, wherein the opposite side of the frame plate comprises a flow channel pattern 30 (flow field channels). An example of such structure is shown in Figures 3A and 3B presenting a cross-section representation of a bipolar plate comprising cathode flow field 31 with a slot (pocket) made of first material, the slot configured to receive (3A) an anode flow-field insert 32 made of second material. Figure 3B shows an assembled bipolar flow filed plate 33.

[0058] A stack usually has end plates at both end of the stack attached to the outermost flow field plates to seal the stack. The end plates may be monopolar flow field plates, such as an anode end plate comprising a pocket configured to receive the insert and / or a cathode end plate comprising a pocket configured to receive the insert. An example of an end plate is shown in Figure 4 presenting a cross- sectional representation of an end plate 34 with a slot (pocket) made of first material, the slot configured to receive a flow-field insert 35 (anode or cathode) made of second material. Figure 3B shows an assembled end plate with insert 36.

[0059] Figures 5A and 5B show cross-sectional representations of two-cell stack configurations consisting of one bipolar plate with insert and normal end plates (5A) or end plate with insert (5B). Figure 5A shows an anode end plate 37, bipolar plate with insert 32 and a cathode end plate 38. Figure 5B shows an anode endplate with insert 36, bipolar plate with insert 32 and a cathode end plate 38.

[0060] It was also found out that it is not necessary to form the conventional flow field plates, or the present inserts, in a traditional way wherein the channels are formed on a metal or graphite plates by engraving. Alternative materials and / or methods for forming the plates and channels are presented herein, which can provide similar or even better properties compared to prior art solutions. These materials and methods can be used in the present modular flow filed plates and in conventional flow field plates.

[0061] The present disclosure provides an electrode comprising an electrically conductive flow field plate insert, which may be a flow field plate insert comprising an electrically conductive portion, and optionally a catalytic portion, wherein the insert comprises one or more open faced channels, i.e. flow fields, on a surface of the insert. The insert may be configured or designed to receive the catalytic portion. Alternatively, or in addition, the insert may comprise the catalytic portion, such as a coating and / or a layer of catalyst, such as wherein the catalytic portion is a gas diffusion electrode or is a part of a gas diffusion electrode, which may be on the insert or part thereof, or otherwise incorporated in the insert or part thereof. Open faced channels are open to the interior of an electrolysis cell when the flow field plate comprising the insert is installed in the cell. The open-faced channels enable flow and contact of liquid and agents contained in the liquid, i.e. are in fluid and / or gas communication, with an electrode and for example with the catalytic portion of the cell, which may be in a form of a sheet. In the present solutions the channels, i.e. the flow channel pattern, may be engraved, but they may also be nonengraved, i.e. they may be formed with other suitable methods, such as methods enabling processing of the used materials, such as plastic or suitable metals.

[0062] An electrolytic device, such as an electrolysis cell or an electrolyzer, uses electricity to split carbon dioxide, water and / or other components into their constituent elements through electrolysis. In general, the anode operates to complete the redox reaction cycle by oxidation reaction of water resulting in oxygen gas (O2) formation. The reduction of CO2 occurs on the cathode via a series of proton-electron transfer processes resulting in formation of the specific reaction product distribution.

[0063] The electrolysis cell may have a casing, a frame or a body, including one or more inlets and one or more outlets for liquids and / or gases, and connections for a source of electrical energy. The flow field plates may form the casing, the frame or the body or a part thereof. The anode and the cathode, and / or the flow field plates, are connected or connectable to a source of electrical energy, such as an external source of electricity, which may be controllable. Electric power, such as with desired and / or controlled voltage and / or current, may be applied to the anode and the cathode, and / or to the flow field plates, to obtain electrochemical, such as electrolytic, reactions in the liquid in contact with the anode and the cathode. The flow field plates may be considered as part of the electrodes, or as the electrodes. The flow field plate may comprise one or more connections for electric energy, more particularly electricity. The connection may comprise one or more connectors for wiring, or apertures or the like receiving portions for the connectors and / or the wiring.

[0064] The electrolytic device may comprise an ion exchange membrane, i.e. an electrolyte membrane, between the anode and the cathode. The ion exchange membrane may be a polymeric membrane, such as comprising perfluorosulfonic acid. The ion exchange membrane may allow anions to pass to the cathode while restricting the passage of protons and other cations. Other substances passing through the ion exchange membrane would disrupt the chemical reaction. The electrolytic device may also comprise a proton exchange membrane. The membrane may be a polymer electrolyte membrane (PEM). The polymer electrolyte membrane may refer to any types of suitable membranes, such as anion exchange membranes (AEM), cation exchange membranes (CEM) or bipolar exchange membranes (BPM). Preferably the ion exchange membrane is an anion exchange membrane

[0065] The frame plate may comprise one or more apertures for inlets and outlets, for example at the sides having the shortest width / thickness. Such apertures may be located on a side of a stack of cells or may be connected to the side of the stack, wherein connectors and / or tubes for incoming and outcoming liquid and / or gases may be connected to the apertures or other receiving parts. In or inside the frame plates the apertures may be connected to the channels. The one or more channels may be therefore connected from one end to an inlet and from other end to an outlet thus allowing circulation of liquid and / or gas through the electrode or cell.

[0066] The frame plate may comprise one or more apertures for attaching to the other parts, such as for assembling the cell, for example with one or more screws, bolts, pins or the like attaching means. The parts of the cell may be sandwiched and preferably attached with the attaching means to obtain a cell. The cell may be designed as a single cell or as a stack of cells in bipolar and / or monopolar configuration, wherein the cells are preferably designed to fit each other i.e. they may have compatible sides and / or attaching portions, which allow the cells to be attached to each other.

[0067] With the present methods and materials, it is possible to obtain flow field plates with a varying thickness, area and / or other dimensions. The depth of the channels may be adjusted to a desired depth range.

[0068] The longest sides of the frame plate may have a length in the range of 5-50 cm, such as 5-30 cm, for example 10-25 cm. The insert has usually a shorter length, such as 5-50 mm shorter. The insert comprising a channelled portion or area is at least partly surrounded by unchanneled and / or elevated areas in the frame plate, such as at the edges of the largest surfaces thereof, which may form a wall around the channelled area. The channelled area may comprise a lowered area, for example 0.05-2 mm, such as 0.05-1 mm, for example 0.05-0.5 mm, 0.1-0.5 mm, 0.1-0.4 mm or 0.2-0.3 mm lower than the surrounding frame plate, which enables placing one or more sheet form parts on the channelled area, such as porous material, for example carbon, which may comprise catalysts, and / or one or more membranes or the like. When two flow field plats are sandwiched, a space is formed between the plates for circulation of liquids and / or gases and for reactions to take place.

[0069] The depth and / or width of open-faced channels in the insert may be adjusted according to needs and may be implemented in a large range. The present materials and methods do not limit the depth or the width, or the shape of the channels. In one example the one or more channels on the surface of the flow field plate have a depth and / or width in the range of 0.3-1 .0 mm. In the present invention, it is possible to form complex channels having different shapes, structures and dimensions, even onto brittle and / or thin inserts. Preferably the channel depth is lower than the thickness of the insert plate.

[0070] The thickness of the flow field plate, such as the frame and / or the insert, may be implemented in a large range. It may be desired to obtain a low thickness, such as in the range of 1.0-5.0 mm, or 10.0-3.0 mm, even 1.0-2.0 mm, to enable a high number of cells in a stack or otherwise compact form of a cell. This can be easily achieved with the present structure even with brittle insert materials. If, however, a higher thickness is desired, for example to enable deep open-faced channels and / or large or complex inner channels, or for other structural reasons, it is also possible to prepare plates, frames and / or inserts with higher thickness.

[0071] The electrolysis cell or the electrolytic device may be designed and / or configured to feed raw material or provide and / or obtain a feed of the raw material, such as liquid comprising or containing carbon dioxide or source thereof i.e. the catholyte, to the cathode and / or water or other aqueous solution, such as a solution comprising one or more electrolytes i.e. the anolyte, to the anode.

[0072] The present disclosure provides an electrolytic device or device arrangement, such as an electrolyzer, comprising one or more of the electrolysis cells, such as comprising one or more gas-fed polymer membrane electrolyte electrolysis cells, or one or more devices comprising the cell(s), the cell comprising a membrane electrode assembly (MEA). The electrodes may be gas diffusion electrodes (GDE) such as shown in Figure 2B, which comprise a gas diffusion layer (GDL) and a catalyst layer (CL). The membrane electrode assembly comprises an anode GDE, a cathode GDE and a membrane between the anode and the cathode, which assembly is encased between an anode flow field plate and a cathode flow field plate.

[0073] In most cases the electrolysis cell comprises

[0074] -an anode comprising or combined with a flow field plate, i.e. a current collector, such as a gas diffusion anode, and / or

[0075] -a cathode comprising or combined with a flow field plate, such as a gas diffusion cathode, and

[0076] -an ion exchange membrane between the anode and the cathode. The flow field plate, in the anode and / or in the cathode, is preferably the present flow field plate, which comprises the conductive insert comprising one or more flow channels and the frame plate.

[0077] The electrodes are in contact with a corresponding flow field plate, such as a cathode 6 is combined with a corresponding cathode flow field plate 1 so that the channels 8 of the cathode flow field plate are in fluid and / or gas communication with the cathode 1 (Fig. 2A). In analogous manner the anode 5 is combined with a corresponding anode flow field plate 2.

[0078] There are several MEA configurations. Preferred configurations include 5-layer systems, where two catalyst layers (one for anode and one for the cathode) are attached to two gas diffusion electrodes (GDEs) and sandwiched between one polymer electrolyte membrane (PEM) resulting in a total of 5 layers. Another configuration includes 3-layer configuration which is essentially the same as the 5 layer, but without the two gas diffusion layers (GDLs), and instead the catalyst layers are directly coated on either side of the PEM. Figure 6 shows an example of a cross-section representation of a two-cell stack configuration with inserts and membrane electrode assemblies (MEAs). The stack configuration comprises an anode end plate with insert 36, bipolar plate with insert 32, membrane electrode assemblies 39, and a cathode end plate 38

[0079] An electrolytic device, which may be an electrolyzer, is a device or a device setup, a system and / or an assembly, or a combination thereof, comprising one or more electrolysis cells, and any associated components, such as one or more of the ones disclosed herein. The electrolytic device may comprise a frame, a casing, a cover and / or the like structural parts, which may include the one or more electrolysis cells. Figure 2A shows a general example of an electrolytic device showing one electrolysis cell.

[0080] An electrolytic device in general is a device that uses electricity to split water and / or other components into their constituent elements through electrolysis. An electrolytic device as described herein refers to a device setup, such as shown in Figure 2C, comprising parts and / or components required to operate the device, including the electrolysis cell(s) and any required other parts and / or components, such as inlets and outlets, and any operating and / or controlling parts and / or components. An electrolytic device may comprise a plurality of electrolysis cells or cell assemblies arranged as a stack, for example wherein the electrolysis cells are flow cells arranged as one or more stack(s). A plurality may refer to two or more, five or more, ten or more, up to hundreds of cells, for example to 2-500, 2-10, IQ- 500, 10-100 or 10-50. An electrolytic device may comprise the electrolysis cell stack(s), pumps, valves, storage tanks, a power supply, a separator, one or more sensors, and / or other operating components. Electrolysis occurs within the cell stacks when an electric current is applied in the system across the electrolytes. The cells in a stack may be connected to the electric current in parallel and / or in series. Bipolar plates are always connected in series. The electrolytic device may be a CO2 electrolytic device.

[0081] Electrolyzers may be classified in three categories: an alkaline electrolyzer, a proton exchange membrane electrolyzer, and a solid oxide electrolyzer (SOE). The electrolyzer is preferably an anion exchange electrolyzer, which is one type of alkaline electrolyzers. The present inserts are also suitable for proton exchange membrane electrolyzers, which contain a proton exchange membrane that may use a solid polymer electrolyte. The electrolyzer may be used for electrolysis of carbon dioxide. When an electrical current is applied to the cell of the electrolyzer during carbon dioxide electrolysis, the carbon dioxide splits into carbon-containing compounds, such as carbon monoxide, and oxygen.

[0082] The electrolyzer may be a gas-fed electrolyzer, at least for the cathode side, and it may comprise one or more gas-fed polymer membrane electrolyte electrolysis cells. The anode side may use a liquid anolyte / electrolyte. The gas may comprise CO2, such as humidified CO2 gas, or any other applicable gas, such as inert gas. The electrolyzer may be a CO2 electrolyzer. The electrolyzer may be a zero-gap electrolyzer, such as a zero-gap CO2 electrolyzer. Similarly, the electrolysis cell may be a zero-gap electrolysis cell. A zero-gap electrolyzer, or a zero-gap electrolysis cell, has no gap between the cathodes, anodes and the polymer electrolyte membrane (PEM). A zero-cap two- compartment electrolyzer or cell can be specifically used for CO2 conversion to non-liquid products.

[0083] In zero-gap electrolyzers both catalyst layers in the cathode and anode GDEs are in direct contact on either side of the membrane. Zero-gap electrolyzer typically constitute in a two-compartment electrolyzer.

[0084] The present disclosure provides an electrolytic device comprising one or more flow field plates, one or more electrodes or one or more electrolysis cells disclosed herein. The electrolysis cells may be arranged as a stack. In such case the flow field plates may be bipolar plates comprising channels on both sides of the plate.

[0085] In one example an electrolytic device, for example an electrolytic device for reducing carbon dioxide to products, such as to hydrocarbons and / or CO, comprises

[0086] -one or more, such as a plurality of, the electrolysis cells or cell assemblies disclosed herein.

[0087] The electrolytic device may comprise

[0088] -an inlet for reactant stream and / or feed, such as a source of carbon dioxide, and -an outlet for reaction products, such as a stream and / or feed thereof.

[0089] The electrolytic device may be a continuous electrolytic device, which may be used for continuous electrolysis of carbon dioxide, preferably humidified carbon dioxide.

[0090] Preferably the electrolytic device comprises two or more of the electrolysis cells. In such case the electrolysis cells may be flow cells arranged as one or more stack(s).

[0091] The electrolytic device may comprise, be connected or be connectable to a power source. Any operating and / or active components may be operatively connected to controlling means. The electrolytic device, the electrolyzer, the electrolyzer system or the assembly may be electronically controllable, thus comprising one or more controlling means. The controlling means may be or comprise one or more electronic control units, which may be programmable, comprising one or more processors, memory, and software configured, when executed with a processor in the control unit, to carry out one or more operations to implement the method, for example to adjust the voltage, current, temperature, pressure and / or flow of liquids and / or gases by controlling and / or adjusting any of the operating components of the device, the system or the assembly. The control unit may be, comprise and / or be connected to a computer. The controlling means may be arranged to maintain one or more of said parameters in a desired range. The controlling means may be arranged, such as programmed, to monitor one or more properties from the device, the system, and / or the assembly, for example as a function of time, and as feedback to the monitored properties carry out one or more control actions in the device or the system to adjust the function of the device to carry out the present method.

[0092] In one example the electrolytic device comprises

[0093] -one or more, such as a plurality, for example two or more, of the electrolysis cells disclosed herein, preferably arranged as a stack, and

[0094] -a power source and / or a power supply and / or wherein the electrolytic device is connectable to a power source and / or a power supply. The power supply or the power source is arranged to provide electric current to the anode and the cathode, or to the electrolysis cell(s). The electrolytic device may comprise connectors and / or wiring for the power source or the power supply. The power supply may refer to a device controlling the application of power and / or properties thereof, which usually converts electric current from a source to the correct voltage, current, and frequency to power the load. Power supply may be referred to as an electric power converter. The power supply may be controllable, for example by controlling means such as a control unit, to which it may be operatively connected, so that desired voltage and / or current may be obtained and provided to the anode and the cathode. The power timing, pulsing, frequency, and / or the like parameters may be also controlled. In one example the power supply comprises or is a potentiostat or a galvanostat, which may be used for controlling the present methods and / or activating methods.

[0095] The electrolytic device may comprise flow and / or pressure control means arranged to control the flow and / or pressure in the electrolysis cell and / or in the electrolytic device. The pressure control means may include one or more sensors for detecting flow and / or pressure in a cell or the electrolytic device, which sensors may be connected to controlling means. The controlling means may be arranged, as feedback to the detected flow and / or pressure, to control one or more devices and / or parameters to adjust the flow and / or pressure in a desired range.

[0096] The cathode and optionally also the anode may comprise a catalyst layer on a support. The cathode may comprise a catalyst layer on a cathode support and the anode may comprise a catalyst layer on an anode support, such as a thin layer of catalyst material disposed on their major surfaces at the interface with the interposed membrane. The catalyst may be different in the cathode and in the anode. In the present invention it was found out how to obtain suitable catalyst in the cathode to promote desired electrolytic reactions. The present cathode can be used with any suitable anode and in any suitable device, device arrangement and / or process.

[0097] The anode comprises anode support, which may comprise or be same material as the cathode support, or it may comprise or be different material. The anode may or may not contain a catalyst on the anode support. If the anode comprises a catalyst, the catalyst may be different from the catalyst on the cathode support. The anode may be prepared by using the same or similar methods, however preferably from different materials.

[0098] In one example the cathode support and / or the anode support comprise porous material, preferably porous electrically conductive material, which may be in a sheet or a layer form, and which may have planar major surfaces, such as carbon fibre paper or other sheet. The cathode support is preferably a cathode support layer and / or the anode support is preferably an anode support layer. A gas diffusion electrode can be obtained by using such a porous electrode support. A gas diffusion electrode comprises the catalytic portion, such as a catalyst layer, as shown in Figure 2B.

[0099] The cathode support and / or the anode support may be a gas diffusion layer (GDL), which may comprise two layers: a macrofibrous layer (a backing layer) and a microporous layer (MPL). The catalyst layer (CL) may be applied and / or adhered to or is on the microporous layer.

[0100] The present electrode may be a gas diffusion electrode. A gas diffusion electrode (GDE) comprises a gas diffusion layer (GDL) and a catalyst layer (CL). The anode may be an anode comprising an anode catalyst layer deposited on a gas diffusion layer (an anode GDE). The cathode may be a cathode comprising a cathode catalyst layer deposited on a gas diffusion layer (a cathode GDE).

[0101] The anode may be based, or comprise, one or more suitable compounds, such as metal, metal oxides, mixed metal and / or mixed metal oxides of Ir, Ru, Rh, Pt, Ni, Fe, such as iridium, lrO2, NiFe, transition metals, and the like materials. Commercially available anode materials may be used in the present devices and methods.

[0102] Disclosed is a metal alloy catalyst, i.e. a mixture of metals, which metal alloy catalyst may be used in electrolytic applications, such as in a cathode. The metal alloy catalyst may comprise or be in a form of nanoparticles.

[0103] A catalyst may comprise one or more transition metal and / or alloy thereof. A catalyst may comprise one or more elements selected from the group consisting of V, Cr, Mn, Fe, Co, Ni, Cu, Sn, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, Hf, Ta, W, Re, Ir, Pt, Au, Hg, Al, Si, In, Tl, Pb, Bi, Sb, Te, U, Sm, Tb, La, Ce, and Nd. In the present case it was found advantageous to use copper in the catalyst, preferably in combination with silver.

[0104] The porous material, such as a sheet or a layer thereof, may be applied onto the open-faced channels, and it may be attached to the plate by using suitable attaching means, and / or it may be immobilized in the electrode or cell structure when the electrodes are sandwiched, for example in the cell.

[0105] It was also found out that it is not necessary to form the flow field plates in a traditional way wherein the channels are formed on a metal or graphite plates by engraving. Methods using a die to form the channels were found suitable for processing various materials suitable for flow field plates, including metal materials but also plastics and composite materials. One method found especially advantageous for forming the channels was embossing, which could be implemented with plates made of a variety of materials. Embossing is a process, which can produce raised or sunken designs. They are usually produced using a specialized embossing machine or using a male and female die set. A process creating sunken designs may be also called debossing. One useful method for forming the channels is stamping. The stamping process may use a manufacturing press to indent the channels into the material. Also, methods including moulding can be used to form channels from metals, plastic and / or other polymers, or composites comprising thereof.

[0106] In one embodiment the one or more open faced channels on the surface of the insert is / are moulded, engraved, embossed, debossed and / or stamped channels, or are obtained by corresponding methods. Muld channels can be obtained by using a suitable mould. Embossing, debossing or stamping can be carried out with any suitable embossing, debossing or stamping device with a suitable die.

[0107] Embossing, debossing or stamping can be implemented as an industrial process, wherein each insert can be processed in one step thus forming the channels in very fast process, which may use a pressing device or the like device, such as manufacturing press. The formed channels were found comparable to prior art engraved channels in quality and functionality. Thus, the complex engraving process, which is slow and also produces waste material, could be avoided.

[0108] It was found out that the insert plates and / or the frame plates can be made of plastic, such as thermoplastic polymers and / or thermosetting polymers. The plastic flow field plates may comprise 60% by weight or more plastic, such as 80% by weight or more, for example 90% by weight or more. This may be the case in composites and / or wherein the plate comprises additional electrically conductive material, such as metal. The plates, such as the body of the plates, may consist of the plastic, and in such case the plates may be for example coated with conductive material. The plastic-containing flow field plates could tolerate the moderate conditions used in most present electrolytic processes, such as temperatures of 100 °C or below, for example 20-100 °C, 20-80 °C, or 20-60 °C. Also, the pressures of the processes are usually in the range of 1-5 bar, such as 1-4 bar, which can be well tolerated by the plastic-containing materials. Also, the reagents, such as anolyte and catholyte, used in the processes does not harm the plastic materials, which are chemically inert and actually more corrosion tolerant than the prior art metals or graphite. Plastics can also tolerate oxidation and mechanical stress, and they are for example not brittle. With plastics it is possible to obtain very light plates, which provide benefits in the handling and transportation of the plates, in the assembly of devices and in the final devices. The cells, stacks and electrolytic devices comprising the present plates comprising light materials may be light in weight and can be easily moved, for example transported to customers, transported to a site of use, and / or arranged, serviced, and handled. The modular structure of the present flow field plates enable removing only an insert from the frame plate, or from a stack, and cleaning or replacing the insert with a new and / or a different one, even without disassembling the whole structure, such as the stack.

[0109] These features, and also other features discussed herein, benefit several operators ranging from production, supply, storing, and transportation to manufacture of devices and to final use.

[0110] In one embodiment the one or more of the parts of the flow field plates, such as the insert and / or the frame plate, comprises one or more plastic polymers, such as thermoplastic polymers and / or thermosetting polymers. The thermoplastic polymer may comprise any suitable thermoplastic polymer or a mixture thereof, which may be plastic. Preferably the plastic polymers can be effectively processed by the present methods, such as by embossing and / or by moulding. Suitable plastic polymers include one or more of synthetic polyamide, polytetrafluoroethylene, polyvinylidene fluoride (PVDF), perfluoroalkoxy alkanes (PFA), ethylene chlorotrifluoroethylene (ECTFE), polychlorotrifluoroethylene (PCTFE), polyetheretherketone (PEEK), polyphenylene sulfide (PPS), and fluorinated ethylene propylene (FEP). These polymers provide good mechanical properties, chemical resistance, temperature resistance and stability, wear resistance, and dielectric properties, which makes them especially suitable as flow field plate materials in the present applications. These polymers can be used as base material for the present composites, which may include reinforcing and / or conductive material.

[0111] The parts of the flow field plates can be also made from composite materials, such as plastic composites, for example plastic-carbon fibre composites, plastic-metal fibre composites, plastic-ceramic composites and the like plastic-reinforcing component composites. The plastic may comprise any suitable plastic polymer, such as one or more disclosed herein. The composite may comprise a conductive component, which may be also a reinforcing component.

[0112] Plastics and composites can be processed with a variety of methods, and it is possible to mould the final flow field plates from plastic-containing material by common moulding methods, such as injection moulding or extrusion moulding. Injection moulding is a manufacturing process for producing parts by injecting molten material into a mould. A suitable mould may be provided, which enables forming the desired channels and also the overall shape of the plate. Material for the part is fed into a heated container, and injected into a mould cavity, where it cools and hardens to the configuration of the cavity. A blank plate may be formed by injection moulding, such as comprising the overall shape of the flow field plate and preferably any recesses and / or channels therein. However, the channels may be also formed with other methods such as by embossing, debossing or stamping.

[0113] The flow field plate is electrically conductive, which may refer to the flow field plate as a whole, or to an electrically conductive portion of the flow field plate. The electrically conductive portion is required to enable the electrolytic reactions. The flow field plate as a whole may form the electrically conductive portion, if the plate is made of or comprises components comprising or made of conductive material. If non-conductive materials are used as the base material of the plate or a part thereof, such as non-conductive plastics, an additional electrically conductive portion shall be provided or arranged in the flow field plate. The electrically conductive portion may be formed as a coating, which may be full or partial coating on the plate, which may be non-conductive and / or uncoated, for example at least covering the channelled portion or area. The coating may be formed before or after forming the channels. For example, at least the surface comprising the channels, or where the channels are to be formed, may be coated. The conductive portion or part thereof may be provided as a separate portion or part, and / or an external part, such as one or more conductive sheets or conductors, may form at least part of the conductive portion. The conductive insert comprising a flow channel pattern represents the separate portion, i.e. the additional electrically conductive portion, and the frame plate comprising on one or both sides a pocket configured to receive the conductive insert represents the flow field plate, to which the additional electrically conductive portion is arranged in.

[0114] In one embodiment the electrically conductive portion comprises an electrically conductive coating. The electrically conductive coating may comprise one or more metals. The coating may be formed with any suitable method, such as by painting, spraying, such as flame spraying, sputtering etc. A suitable coating solution or dispersion may be provided, which contains one or more conductive metals or precursors thereof, such as silver, copper, aluminium, nickel, for example as nanoparticles.

[0115] In one embodiment the electrically conductive portion comprises electrically conductive plastic or composite. The plastic may be or comprise thermoplastic polymer, such as electrically conductive thermoplastic polymer or thermoplastic polymer comprising electrically conductive additive and / or material, for example any of the ones disclosed herein. The electrically conductive plastic or composite may be obtained by incorporating one or more suitable conducting additive and / or material to the base material, i.e. the plastic or composite. In example the electrically conductive plastic or composite comprises one or more of carbon fillers, such as carbon black, graphite, carbon fibres, nanostructured carbon, such as carbon nanotubes, or the like, metal fibres and / or particles, conductive polymers, and / or the like. Also, the conductive plastic or composite may be coated with electrically conductive coating.

[0116] The channels may be formed in any suitable form. For example, the one or more channels on the surface of the one or more flow field plates may comprise a design selected from serpentine, parallel, pin-type, mesh-type, fractal type, and interdigitated flow fields.

[0117] The serpentine design is a traditional design and comprises a single continuous channel covering the whole area of the FFP. A single inlet is connected to a single outlet. The reactant gases can move everywhere from the FFP. The serpentine design has emerged as an industry standard because of its robust performance and ability to reproduce results. The serpentine design may comprise a single serpentine channel, double serpentine channel, a plurality of, such as three or four, serpentine channels, or a symmetric arrangement of a plurality of, such as four, serpentine channels.

[0118] In examples the one or more of the parts of the flow field plates comprises non- metal, non-graphite and / or non-composite material. The non-metal material may specifically refer to non-steel / non-iron materials and / or to other materials not commonly used in prior art flow field plates. The non-composite may exclude plastic composites.

[0119] Metals can be used as base material in the parts of the present flow field plates. In one embodiment the one or more of the flow field plates comprises metal comprising moulded, engraved, embossed, debossed and / or stamped channels. More particularly the plate may be or may be made of metal, and the channels may be obtained by moulding, engraving, embossing, debossing and / or stamping.

[0120] The metals may comprise steel, titan and / or other suitable metals, or combinations thereof. For example, one side of the plate may comprise steel and / or the other side may comprise titan. The metal(s) may be also included in a non-metallic plate. The metal may be corrosion-resistant metal, such as stainless steel, carbon steel, galvanized steel, high pitting resistance steel, aluminium, or red metals such as copper, bronze or brass.

[0121] The inserts may comprise or be made of non-continuous and / or porous material, such as mesh, sintered material or felt or the like material comprising fabric, grid or the like structure, for example comprising fibres, wires, and / or the like elongated material. Such materials may be or comprise woven or non-woven material. In one embodiment one or more of the inserts comprises a mesh structure. The channels or flow channel patterns are formed by apertures or pores / porosity of the insert or material thereof, such as the mesh or the other porous materials. In such case the conductive insert comprising a flow channel pattern may be a conductive insert comprising a flow channel apertures or pores, i.e. the flow channel apertures or pores form the flow channel pattern. The non-continuous and / or porous material may be provided as sheets, such as insert-shaped sheets, and they may include one or more reinforcing and / or rigid parts, such as parts at the edges and / or passing through the sheet, which may be needed especially in case of flexible material, for example to obtain inserts with required rigidity and to enhance handleability thereof.

[0122] A mesh structure may comprise one or more meshes, such as wire mesh. A mesh may be a grid and / or a network, and the mesh may also include the felt and / or the sintered form. The non-continuous and / or porous material, such as the mesh, the felt and / or the sintered forms, may comprise or be made of metal, such as steel and / or titan; and / or of other applicable materials, such as graphite and / or one or more polymers, and / or mixture and / or composite thereof, wherein the material may comprise fibres or fibrous materials, wires, and / or the like parts; and / or structures and / or combinations of the materials disclosed herein. In one embodiment the mesh structure comprises a metal mesh. The mesh may comprise steel, titan or a combination thereof. The mesh may also comprise or be made of other materials, such as the plastics, polymers and / or the composites disclosed herein. The materials may be processed into suitable form, such as into elongated forms such as fibres, wires, reinforcing parts and / or the like, for example by extrusion moulding, which can then be formed into a mesh structure. The felt may be a sintered felt. In one example a sintered felt is made of stainless steel, titanium, and / or other applicable metal fibres or graphite fibres, which may have a diameter of micro rating, by sintering in high temperature and welding after non- woven laying. Conductive portions may be formed by any suitable method, such as by coating and / or by incorporating conductive material to the plastic, composites, fibres, meshes or the like, in the same manner as described herein for continuous materials.

[0123] In a mesh structure there are necessary no predetermined flow channels for the liquid. This is advantageous in certain applications. For example, very efficient liquid flow can be obtained, the catalysts can be efficiently integrated in the mesh structure, and / or the mesh itself can act as an anode and / or a cathode. This is useful for example in structures wherein the casing, the body or the frame of a cell or an electrolytic device is made of polymeric material, such as organic polymers, for example plastics. A mesh structure can provide a very large reaction surface, which increases the efficiency of the electrode and the devices comprising the electrode.

[0124] One example provides a method for preparing an insert, the method comprising -providing a blank insert plate without channels, and

[0125] -forming one or more open faced flow field channels to a surface of the blank insert by embossing.

[0126] The blank insert plate may have the form of the insert plate except that no channels and / or conductive portion is / are included. The blank insert plate may comprise continuous material, such as in a form of a sheet, a block or the like, which can be processed into a form of the present insert plate. The blank insert plate may comprise or be made of any of the material disclosed herein, such as plastic or metal.

[0127] The preparation methods may comprise coating the insert plate, or a non- conductive and / or uncoated insert plate, comprising the one or more open faced channels, such as moulded, engraved, embossed, debossed and / or stamped channels, and / or channels formed by apertures or pores of the material, with an electrically conductive coating.

[0128] The present disclosure provides a method for preparing an electrolysis cell, the method comprising providing one or more flow field plates and / or electrodes disclosed herein, and assembling an electrolysis cell comprising

[0129] -a membrane electrode assembly (MEA) comprising -one or more anodes comprising or combined with the flow field plate, and / or

[0130] -one or more cathodes comprising or combined with the flow field plate, and

[0131] -an ion exchange membrane between the anode and the cathode.

[0132] In one example the electrolysis cell comprises a membrane electrode assembly comprising

[0133] -one or more anodes comprising or combined with the flow field plate, and / or -one or more cathodes comprising or combined with the flow field plate, and -an ion exchange membrane between the anode and the cathode.

[0134] The method may comprise providing the catalytic portion(s), such as porous material, for example one or more gas diffusion electrodes, the ion exchange membrane, and / or a casing or parts of a casing and any other parts required for preparing the cell.

[0135] The anode and / or the cathode may comprise bipolar flow field plates, especially if the electrolysis cell is prepared and / or provided for preparing a stack of the cells. Non-bipolar (monopolar) plates may be provided to be placed to the ends of a stack. The electrolysis cell may be prepared by a cell manufacturer, which may be different from the electrode manufacturer. Further, the electrolytic device may be prepared by an electrolytic device manufacturer by using the electrolysis cells provided by the cell manufacturer.

[0136] The present disclosure provides a method for preparing or assembling an electrolytic device, the method comprising providing two or more electrolysis cells disclosed herein, preferably bipolar flow field plates comprising frame plates in the form of bipolar plates comprising a pocket configured to receive the insert on one or both sides of the frame plate, and assembling an electrolytic device comprising a stack of the electrolysis cells, preferably assembling an electrolytic device setup or the like device. The method may comprise providing further components and / or parts required for manufacturing the electrolytic device, which may include one or more components and / or parts such as frame, casing, cover, tubing, wiring, connectors, valves, actuators, attaching means, controlling means, sensors and the like parts, which may be usually required to build an electrolytic device. The present electrolysis cells or electrolytic device may be used in suitable electrolytic methods. Carbon dioxide may be converted into one or more type of reaction products, i.e. compounds, including carbon monoxide, hydrocarbons and / or CxHyOz products, as well as H2 and O2 as byproducts. In one example the method is a method for converting, such as reducing, carbon dioxide to products, such as to hydrocarbons, alcohols, carboxylic acids and / or CO, the method comprising

[0137] -providing the electrolysis cell or the electrolytic device,

[0138] -providing a source of carbon dioxide,

[0139] -conveying the carbon dioxide to the electrolysis cell and / or the electrolytic device, -applying electrical current and / or potential to the anode and the cathode to provide electrolysis to electrocatalytically reduce the carbon dioxide to generate products, and

[0140] -separating and / or recovering the generated products, such as one or more of hydrocarbons, alcohols, carboxylic acids and CO.

[0141] The present methods and devices can be used for conversion of CO2 to C1 or C2 compounds, such as one or more of CO, H2CO, H2CO2, CH3OH, CH4, C2H4, CH3CH2OH, CH3COOH, C2H6, and (COOH)2.

[0142] Disclosed are any uses of the materials, parts or devices herein for any purpose described herein, such as for carrying out any of the methods or combinations or parts thereof.

[0143] Examples

[0144] Flow field plates according to Figures 3-5 comprising an insert and a frame plate were prepared and assembled, and used in stacks comprising the membrane electrode assembly of Figure 6. One example of the flow field plate structure is shown in Figures 7A and 7B. The insert shown in Figures 7A and 7B includes on top of the flow channel pattern a carbon fibre paper, which is a part of the MEA structure. The frame plate comprises apertures for attachment and for inlets and outlets (Figure 7A). The pocket, and the edges of the frame, have been made by machining, and the machining path reflects light and resembles patterning. However, in reality the bottom of the pocket is substantially flat. The anode inserts 32, 35 were made of thin titanium sheets with engraved flow channels. The frame plate 31 comprising engraved channels on the opposite side to the anode 32 was made of stainless steel and acted as a cathode. Corresponding anode and cathode end plates were implemented in the stack as shown in Figures 4A and B. The number of bipolar flow field plates 32 and MEAs 39 was varied, and electrolyzers comprising the stacks were tested for electrocatalytically reducing carbon dioxide. The performance of the electrolyzer was at the same level as performance of prior art electrolyzers.

[0145] To access the inserts the electrolyzer needed not to be completely disassembled, but only releasing the attachments of adjacent bipolar plates was needed to allow access to the inserts, which could be removed and replaced.

Claims

Claims1 . A flow field plate comprising-a conductive insert comprising a flow channel pattern, and-a frame plate comprising on one or both sides a pocket configured to receive the insert.

2. An electrolysis cell comprising-a membrane electrode assembly comprising-an anode combined with a flow field plate, such as an electrically conductive flow field plate, for example wherein the anode is a gas diffusion anode,-a cathode combined with a flow field plate, such as an electrically conductive flow field plate, for example wherein the cathode is a gas diffusion cathode, and preferably-an ion exchange membrane, such as an anion exchange membrane, between the anode and the cathode, wherein one or more of the flow field plates comprises-a conductive insert comprising one or more flow channels, and-a frame plate comprising a pocket configured to receive the insert on one or both sides of the frame plate.

3. The flow field plate of claim 1 or the electrolysis cell of claim 2, wherein the flow field plate is a bipolar flow field plate comprising-a conductive insert comprising a flow channel pattern, and-a frame plate comprising a pocket configured to receive the insert on one side of the frame plate, wherein the opposite side of the frame plate comprises a flow channel pattern4. The flow field plate of claim 1 or 3 or the electrolysis cell of claim 2 or 3, wherein the conductive insert comprises or consist of titanium, graphite and / or high pitting resistance steel.

5. The flow field plate of claim 1 or 3-4 or the electrolysis cell of any of claims 2-4, wherein the conductive insert comprises one or more polymers, such as plastic polymers, such as wherein the plastic polymer comprises one or more of a synthetic polyamide, polytetrafluoroethylene, polyvinyl idene fluoride (PVDF),perfluoroalkoxy alkanes (PFA), ethylene chlorotrifluoroethylene (ECTFE), polychlorotrifluoroethylene (PCTFE), polyetheretherketone (PEEK), polyphenylene sulfide (PPS), and fluorinated ethylene propylene (FEP).

6. The flow field plate of claim 5 or the electrolysis cell of claim 5, wherein the conductive insert comprises electrically conductive plastic, such as thermoplastic polymer.

7. The flow field plate of any of claims 1 or 3-6 or the electrolysis cell of any of claims 2-6, wherein the conductive insert comprises an electrically conductive portion comprising an electrically conductive coating.

8. The flow field plate of any of claims 1 or 3-7 or the electrolysis cell of any of claims 2-7, wherein the frame plate comprises or consists of one or more plastic polymers, stainless steel, and / or composite material.

9. The flow field plate of claim 8 or the electrolysis cell of claim 8, wherein the conductive insert comprises metal comprising moulded, engraved, embossed, debossed and / or stamped channels, or is made of metal and the channels are obtained by moulding, engraving, embossing, by debossing and / or by stamping.

10. The flow field plate of any of claims 1 or 3-9 or the electrolysis cell of any of claims 2-9, wherein the conductive insert comprises non-continuous and / or porous material, wherein the one or more flow channel patterns are formed by apertures or pores of the material.

11. The flow field plate of claim 10 or the electrolysis cell of claim 10, wherein the non-continuous and / or porous material comprises a mesh structure, sintered material or felt, such as comprising metal, such as steel and / or titan; and / or graphite and / or one or more polymers, and / or mixture and / or composite thereof.

12. An electrolytic device comprising one or more flow field plate of any of claims 1 or 3-11 or one or more electrolysis cells of any of claims 2-11 , preferably arranged as a stack, and preferably any associated components.

13. A method for preparing a flow field plate, such as the flow field plate of any of claims 1 or 3-12, the method comprising-providing a conductive insert comprising a flow channel pattern,-providing a frame plate comprising a pocket configured to receive the insert on one or both sides of the frame plate, and-inserting the conductive insert to the pocket in the frame plate to form a flow field plate.

14. The method of claim 13, comprising coating an insert plate comprising the one or more open faced moulded, engraved, embossed, debossed and / or stamped channels, and / or channels formed by apertures or pores of the insert, with an electrically conductive coating.

15. A method for preparing an electrolysis cell, the method comprising providing one or more flow field plates of any of claims 1 or 3-12, such as in the form of bipolar plates comprising a frame plate comprising a pocket configured to receive the insert on one or both sides of the frame plate, and assembling an electrolysis cell comprising-a membrane electrode assembly (MEA) comprising-an anode combined with the flow field plate, and / or-a cathode combined with the flow field plate, and-an ion exchange membrane, such as an anion exchange membrane, between the anode and the cathode.

16. A method for preparing an electrolytic device, the method comprising providing two or more electrolysis cells of any of claims 2-12 comprising frame plates in the form of bipolar plates comprising a pocket configured to receive the insert on one or both sides of the frame plate, and assembling an electrolytic device comprising a stack of the electrolysis cells.

Images