Stackable electrosynthesis or electrical energy cells

Abstract

Disclosed is an electric energy or electrosynthesis cell having an architecture that allows the electric energy or electrosynthesis cell to be easily stacked into a cell stack. The cell includes a polymeric cell frame incorporating functional materials therein, such as an interelectrode separator, an electrode, and a metal bipolar plate. For example, the electric energy or electrosynthesis cell includes a polymeric cell frame, a first electrode and a second electrode, and an interelectrode separator disposed between the first electrode and the second electrode. A compression component is disposed adjacent to the first electrode. The compression component may be a metal bipolar plate compression component and / or a metal porous transport layer compression component. In one example, the polymeric cell frame is sealed to the metal bipolar plate by a polymer-metal bond. In another example, at least one polymeric structural positioning component positions the metal bipolar plate to the polymeric cell frame. Disclosed is a cell stack including a plurality of cells.

Description

[Technical field]

[0001] The present invention relates generally to electrochemical cells, for example for use as electrosynthesis or electrical energy cells. Example embodiments relate to cells having an architecture that allows the cells to be easily stacked into industrial cell stacks that effectively form a single electrosynthesis or electrical energy device or apparatus. [Background technology]

[0002] An electric energy cell is an electrochemical cell that produces electrical power for sustained periods of time for use outside the cell. Electrical energy cells are distinguished from other galvanic cells in that they require a constant external supply of reactants. The products of the electrochemical reactions must also be constantly removed from such cells. Unlike batteries, electric energy cells do not store chemical or electrical energy within the electric energy cell.

[0003] Examples of electrical energy cells include, but are not limited to, polymer electrolyte membrane (PEM) hydrogen-oxygen fuel cells, hydrogen-oxygen alkaline fuel cells, ammonia fuel cells, and the like.

[0004] Similarly, an electrosynthesis cell may be considered to be an electrochemical cell that produces one or more chemicals for a sustained period of time for use outside the cell. The chemicals may be in gas, liquid, or solid form. Like an electric energy cell, an electrosynthesis cell also requires a constant supply of reactants and a constant removal of products. In general, an electrosynthesis cell may also require a constant input of electric energy.

[0005] Examples of electrosynthesis cells include, but are not limited to, water electrolysis cells, chlor-alkali cells, and cells for producing hydrogen peroxide, ammonia, and the like.

[0006] Another characteristic of electrosynthesis cells or electrical energy cells is that they typically involve large amounts of reactants and products in their operation, and such cells must be constantly supplied with significant amounts of reactants while at the same time constantly removing significant amounts of products.

[0007] Due to the large amount of electrical energy involved in the operation of electric energy cells and electrosynthesis cells, a major challenge in their development is to make them as energy efficient as possible during operation. This can be achieved, in part, by minimizing electrical impedance. Impedance is the resistance that a cell circuit presents to current flow when a voltage is applied. One well-known method of minimizing impedance is to employ a cell architecture in which the anode and cathode electrodes of the cell are positioned as close to each other as possible, facing each other, without contact (which would create a short circuit). The gap between the two electrodes should then ideally be occupied by an electrolyte that has the highest possible electrical conductivity. Generally, as a type, liquid electrolytes have the highest electrical conductivity. Liquid electrolytes may be incorporated into a porous interelectrode spacer that prevents the electrodes from touching each other. Thus, many electric energy or electrosynthesis cells employ liquid electrolytes, which can be highly conductive, inside the cell, or the component half-cells themselves.

[0008] Another challenge with this type of electrical energy cell or electrosynthesis cell is that in industrial applications they are often ideally "stacked" in electrical series with multiple other cells to create a "cell stack." This is most commonly achieved in a so-called "filter press" arrangement, where individual cells with a substantially flat profile are stacked between two end plates.

[0009] The challenges of making and maintaining filter press type cell stacks are well known. First, it is essential that the cell design and architecture must allow the cells to be easily and reliably integrated into a filter press type cell stack. This means that when the cells are compressed together between the end plates to form the filter press type cell stack, they must seal against each other to ensure that there is no leakage of liquids and / or gases from the cell stack or undesired mixing of liquids and / or gases within the stack. This often requires a very even distribution of compression across the lateral length of the cells in the stack, as well as a very specific and / or high overall compression level. Also, the compression may need to be very even across each face of the individual cells, so that there are no places where there is too much or not enough compression relative to the front or back face of any cell in the stack. Each cell may also need to be very precisely positioned relative to the other cells before and during the application of compression. Achieving these requirements is often difficult, especially in a mass production environment where such precision must be achieved in a minimum of time.

[0010] In addition, after the formation of the cell stack, a compression, often very high and / or very specific, must typically be precisely maintained to ensure that no leakage of liquids and / or gases or undesired mixing of liquids and / or gases occurs during electrochemical operation. However, the cell stack may be cycled between low and high temperatures and low and high pressures during operation, which causes thermal and / or pressure induced expansion and contraction of the cells in the stack. The resulting dimensional changes change the lateral and facial compression experienced by the individual cells, which may induce leakage of liquids and / or gases from the cell stack or undesired mixing of liquids and / or gases within the stack. For this reason, the thermal or pressure induced expansion rate of each cell component must be carefully considered and matched as much as possible. If this is not possible or feasible, appropriate gaskets must be applied between adjacent components to avoid leakage of liquids and / or gases from the cell stack or undesired mixing of liquids and / or gases within the stack. However, the gaskets may move or deteriorate during successive thermal and / or pressure cycles, causing them to fail. Finding ways to minimize, or at least reduce, the number of gaskets required in a stack and the operating stresses placed on the gaskets represents a significant area of ​​innovation.

[0011] As an example, known electrochemical stacks employ metal plates known as bipolar plates that are located between cells in the stack and are held in place only by compression applied across the stack. A bipolar plate is a conductive plate in an electrical energy or electrosynthesis cell stack that connects the anode of one cell to the cathode of an adjacent cell. Its primary function is to store electrical current and distribute it evenly from one cell to the next. A bipolar plate may have complex patterns for fluid flow etched, machined, stamped, sunk, or otherwise formed on its surface. These patterns, often known as flow fields, may consist of pits (i.e., low points on the metal structure) and lands (i.e., high points on the metal structure), or ribs and spaces, or steps and voids. For example, a metal bipolar plate with a serpentine flow field has one or more channels in a serpentine arrangement sunk into its surface. This type of metal flow field may be most conveniently produced by high-speed, high-volume imprinting of the flow field into the metal plate, often using an industrial precision stamping or molding process. However, the physical dimensions of structures made in this way in metal plates may vary slightly due to "springback" of the metal in the plates. The resulting dimensional changes may cause serious problems in stacks containing such bipolar plates, such as leakage due to dimensional changes or imprecise flow dynamics. Thus, a major challenge to industrializing cell stack production is to produce components in a high-speed, high-volume process that results in structures with minimal physical dimensional variations (i.e., exhibiting high "tolerances"). Alternatively, new approaches are needed to successfully and reliably form cell stacks using components with structures that exhibit notable physical dimensional variations (i.e., exhibiting low "tolerances").

[0012] Another metal component often used in electrosynthesis cells or electrical energy cells is known as a porous transport layer. A porous transport layer is a conductive metal structure that is porous to liquid and / or gaseous fluids and is typically located between the electrodes and their bipolar plates. The porous transport layer provides electrical connection between the electrodes and the bipolar plates while allowing the movement of liquids or gases to or from the electrodes.

[0013] Thus, there is a need to address or ameliorate one or more of these problems. For example, there is a need to develop cells or components that can be simply and reliably formed into cell stacks that do not leak or mix with liquid or gaseous reactants and products, both during the stack assembly process itself and thereafter during subsequent operation. In another example, there is a need to develop an approach to the assembly of cell components with low tolerances that results in reliable and successful cell stacks that do not leak or mix with liquid or gaseous reactants and products, both during the formation of the cell stack and thereafter during subsequent operation. This needs to be achieved while at the same time providing high energy efficiency in the operation of the cells and cell stacks.

[0014] The reference in this specification to a prior document (or information derived therefrom) or to public knowledge is not to be construed as an admission or acknowledgement, or any form of suggestion, that said prior document (or information derived therefrom) or public knowledge forms part of the common general knowledge in the field of endeavour to which this specification pertains. Summary of the Invention [Means for solving the problem]

[0015] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify all of the key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0016] In various example aspects, embodiments relate to electric energy cell architectures or electrosynthesis cell architectures that provide simplified and reliable assembly into or within cell stacks without leakage or mixing of liquid or gaseous reactants and products, both after assembly and during subsequent operation, while providing high energy efficiency.

[0017] Exemplary embodiments relate to electrical energy cell architectures or electrosynthesis cell architectures that include a polymeric cell frame incorporating functional materials therein or around the interelectrode separator, electrodes, porous transport layers, bipolar plates, etc. Preferably, some or all of the individual functional materials may be attached to the cell frame. For example, a polymeric interelectrode separator may be attached to the polymeric cell frame via one or more interpolymer bonds. The interpolymer bonds may seal the joint between the polymeric interelectrode separator and the polymeric cell frame against leakage of gas from one side of the interelectrode separator to the other side, for example, across the thickness of the interelectrode separator.

[0018] Preferably, the polymeric inter-electrode separator is thin, thereby maximising the energy efficiency of the cell. Preferably, the polymeric inter-electrode separator has a thickness of less than 0.35mm, less than 0.2mm, less than 0.1mm, less than 0.05mm or less than 0.025mm.

[0019] In another example, one or more of the metallic functional materials may be attached to the polymer frame via one or more polymer-metal bonds. For example, a metallic bipolar plate may be attached to the cell frame via one or more polymer-metal bonds. The polymer-metal bonds may seal the joint between the metallic bipolar plate and the polymer cell frame against leakage of, for example, liquids or gases to or from the exterior of the cell.

[0020] In various embodiments, an assembled "internal compression" electric energy cell or electrosynthetic cell is provided that has an architecture that allows the cells to be easily stacked into a cell stack. The cell includes a polymeric cell frame that incorporates functional materials therein, such as interelectrode separators, electrodes, and metal bipolar plates. For example, the electric energy cell or electrosynthetic cell includes a polymeric cell frame, a first electrode and a second electrode, and an interelectrode separator disposed between the first electrode and the second electrode. A compression component is disposed adjacent to the first electrode, and the compression component exerts a clamping force on the first electrode, thereby compressing the first electrode against the interelectrode separator. The compression component may be a metal bipolar plate compression component and / or a metal porous transport layer compression component. In one example, the polymeric cell frame is sealed, in whole or in part, to the metal bipolar plate by a polymer-metal bond that provides the necessary stiffness in the assembled cell to generate the clamping force described above. In another example, at least one polymeric "structural positioning component" coupled to the polymeric cell frame by a polymer-to-polymer bond positions the metal bipolar plate relative to the polymeric cell frame and provides, in whole or in part, the necessary stiffness in the assembled cell to generate the clamping forces described above.

[0021] A polymeric "structural positioning component" is a polymeric structure within an electrosynthesis cell or electrical energy cell that, when attached to a polymeric cell frame by one or more interpolymer bonds, mechanically holds a physically separate metal structure in the appropriate position within or around the cell and / or cell frame.

[0022] A "compression component" is a spring or sprung structure that, when properly positioned within an assembled cell, exerts a clamping force on at least one of the electrodes, thereby compressing at least one of the electrodes against the interelectrode separator. In so doing, the assembled cell is "internal compressed". Such "internal compression" reduces or avoids the need to generate the necessary clamping force during the formation of the cell stack. In conventional electric energy or electrosynthetic filter press cell stacks, the necessary clamping force on each cell is generated during the compression and assembly of the cell stack, which involves the simultaneous assembly and compression of a large number of cells. However, when pre-assembled cells that are "internal compressed" are integrated into a cell stack, they may not need to be positioned and compressed as precisely as is normally required. That is, by pre-assembling the individual cells in an "internal compressed" form, the process of forming the cell stack can be simplified and accelerated, which can be useful in automated mass production of cell stacks. Also, such pre-assembled and "internal compression" cells may be individually tested and subjected to quality control and validation procedures before being integrated into a cell stack, thereby ensuring that they function properly within the stack. This option is not available in conventional filter press cell stacks, where individual cells are only assembled into functional units during the formation of the cell stack. If one cell thus assembled is found to function improperly, the entire stack must be disassembled to remove it. Preferably, the above-mentioned spring action or sprung action is generated within at least one of the metallic bipolar plates or the metallic porous transport layer.

[0023] A "bipolar plate compression component" refers to a bipolar plate that also has a compression function. That is, the bipolar plate compression component is a spring or spring structure that, when placed in an assembled cell, exerts a clamping force on the associated electrode, thereby compressing the associated electrode against the interelectrode separator. It should be understood that such spring action is preferably designed into the bipolar plate compression component such that the bipolar plate compression component exerts a specific, pre-determined clamping force on the electrode within a relatively narrow clamping force range. The bipolar plate compression component does not exert a clamping force merely by chance or in an uncontrollable or unrepeatable manner. Preferably, the clamping force in the assembled cell is created, in whole or in part, by the stiffness of (1) the polymer-metal bond between the bipolar plate compression component and the polymer cell frame, or (2) the polymer-polymer bond between the "polymeric structural positioning" element and the polymer cell frame.

[0024] A "porous transport layer compression component" refers to a porous transport layer that also has a compression function. That is, the porous transport layer compression component is a spring or spring structure that, when properly positioned in an assembled cell, exerts a clamping force on the associated electrode, thereby compressing the associated electrode against the interelectrode separator. It should be understood that such spring action is preferably designed into the porous transport layer compression component such that the porous transport layer compression component exerts a specific, pre-determined clamping force on the electrode within a relatively narrow clamping force range. The porous transport layer compression component does not exert a clamping force merely by chance or in an uncontrollable or unrepeatable manner. Preferably, the clamping force in the cell is created in whole or in part by the stiffness of (1) the polymer-metal bond between the bipolar plate compression component and the polymer cell frame, or (2) the polymer-to-polymer bond between the "polymeric structure positioning" element and the polymer cell frame.

[0025] Additionally, different compression components are provided, such as a "metal bipolar plate compression component," a "metal porous transport layer compression component," and / or a "metal electrode compression component." Such structures are metallic structures that are spring structures or spring structures that, when properly positioned within an assembled cell, exert a clamping force on an associated electrode, thereby compressing the associated electrode against the interelectrode separator.

[0026] Preferably, the clamping force exerted internally within the assembled cell by the compression components on the electrodes, compressing the electrodes against the inter-electrode separator, is greater than 0.01 bar, greater than 0.02 bar, greater than 0.03 bar, greater than 0.04 bar, greater than 0.05 bar, greater than 0.075 bar, greater than 0.1 bar, greater than 0.2 bar, greater than 0.3 bar, greater than 0.5 bar, greater than 0.75 bar, greater than 1 bar, greater than 2 bar, greater than 3 bar, greater than 4 bar, greater than 5 bar, greater than 10 bar, greater than 15 bar, or greater than 20 bar.

[0027] Preferably, the clamping force exerted internally within the cell when assembled by the metallic bipolar plate compression components against the first electrode or second electrode, compressing the first electrode or second electrode against the inter-electrode separator, is greater than 0.01 bar, greater than 0.02 bar, greater than 0.03 bar, greater than 0.04 bar, greater than 0.05 bar, greater than 0.075 bar, greater than 0.1 bar, greater than 0.2 bar, greater than 0.3 bar, greater than 0.5 bar, greater than 0.75 bar, greater than 1 bar, greater than 2 bar, greater than 3 bar, greater than 4 bar, greater than 5 bar, greater than 10 bar, greater than 15 bar, or greater than 20 bar.

[0028] Preferably, the compression exerted internally within the assembled cell is greater than 0.01 bar, greater than 0.02 bar, greater than 0.03 bar, greater than 0.04 bar, greater than 0.05 bar, greater than 0.075 bar, greater than 0.1 bar, greater than 0.2 bar, greater than 0.3 bar, greater than 0.5 bar, greater than 0.75 bar, greater than 1 bar, greater than 2 bar, greater than 3 bar, greater than 4 bar, greater than 5 bar, greater than 10 bar, greater than 15 bar, or greater than 20 bar.

[0029] Preferably, but not exclusively, the cell architecture also incorporates at least one "compliant" component that displaces to uniformly accommodate and distribute the compressive force exerted by at least one spring or spring component. Optionally, the compliant component includes at least one of a metallic bipolar plate, a metallic porous transport layer, or a metallic electrode. That is, different compliant components can be provided, such as, for example, a "metallic bipolar plate compliant component," a "metallic porous transport layer compliant component," and / or a "metallic electrode compliant component."

[0030] In one aspect, an electric energy or electrosynthesis cell is provided that includes a polymeric cell frame, a first electrode, and a second electrode. An inter-electrode separator is disposed between the first electrode and the second electrode. A metallic bipolar plate compression component is disposed adjacent to the first electrode, such that the bipolar plate compression component exerts a clamping force on the first electrode, thereby compressing the first electrode against the inter-electrode separator. Preferably, the polymeric cell frame is sealed to the metallic bipolar plate compression component.

[0031] In one example, the seal between the polymeric cell frame and the metallic bipolar plate compression component is formed by a polymer-metal bond. In another example, at least one polymeric structural positioning component bonded to the cell frame by one or more polymer-to-polymer bonds positions the metallic bipolar plate compression component relative to the polymeric cell frame. In this example, the seal between the polymeric cell frame and the metallic bipolar plate compression component can be formed by one or more polymer-to-polymer bonds between the at least one polymeric structural positioning component and the polymeric cell frame, and the at least one polymeric structural positioning component mechanically holding the metallic bipolar plate compression component relative to the polymeric cell frame.

[0032] In another aspect, an electric energy or electrosynthesis cell is provided that includes a polymeric cell frame, a first electrode, and a second electrode. An inter-electrode separator is disposed between the first electrode and the second electrode. A metallic porous transport layer compression component is disposed adjacent to the first electrode opposite the inter-electrode separator. A metallic bipolar plate is disposed adjacent to the metallic porous transport layer compression component opposite the first electrode. Preferably, the metallic bipolar plate is secured to the polymeric cell frame by one or more polymer-metal bonds, or at least one polymeric structural positioning component bonded to the cell frame by one or more polymer-polymer bonds positions the metallic bipolar plate relative to the polymeric cell frame.

[0033] Preferably, further, some or all of the metallic functional materials of each half-cell within the entire cell may be attached to each other by one or more intermetallic bonds, such as, but not limited to, one or more intermetallic welds. For example, the metallic electrodes and metallic bipolar plates, including the metallic components of a single half-cell, may be attached to each other via one or more intermetallic bonds, such as, but not limited to, one or more intermetallic welds. In the alternative, the metallic electrodes, metallic porous transport layers, and metallic bipolar plates, including the metallic components of a single half-cell, may be attached to each other via one or more intermetallic bonds, such as, but not limited to, one or more intermetallic welds. The term "intermetallic welds" as used herein refers to any form of metallurgical intermetallic bonding that may be considered to involve welding, including, but not limited to, fusion welding and pressure welding.

[0034] Intermetallic bonds, such as metal-to-metal welds, can provide reduced or unchanged electrical resistance between the metallic functional materials, thereby providing improved energy efficiency by the cells during operation. Preferred embodiments can employ such intermetallic bond structures because the compression involved in cell assembly is too low to damage or destroy the intermetallic bonds, such as intermetallic welds, and again low compression may be required when the assembled cells are subsequently integrated into a cell stack. In contrast, as discussed in the background section, conventional cell stack formations typically require much higher compression, and such high compression can easily damage or destroy existing intermetallic bonds (e.g., intermetallic welds).

[0035] Preferably, but not exclusively, one or more of the metallic functional materials thus attached to each other may be further attached to the polymeric cell frame via one or more metal-polymer bonds. For example, a bipolar plate in a metal-to-metal bond assembly of the type described above may be attached to the polymeric cell frame by one or more metal-polymer bonds. The metal-polymer bonds may, for example, seal the joint between the metallic bipolar plate and the polymeric cell frame against leakage of liquids or gases to or from the exterior of the cell.

[0036] In another example embodiment, a polymeric "structural positioning component" is provided. When attached to the polymeric frame via one or more interpolymer bonds, such a polymeric "structural positioning component" can mechanically hold one or more of the metal functional materials in the appropriate position within or around the cell frame after assembly of the cell. In that way, the metal functional materials can be appropriately positioned within or around the cell frame without being physically bonded to the cell frame. For example, a "structural positioning component" can be attached to the polymeric cell frame via one or more interpolymer bonds, thereby mechanically holding the aforementioned intermetallic bonded assembly of metal electrodes and metal bipolar plates, optionally with a metal porous transport layer, in the appropriate position within or around the cell frame after assembly of the cell. In that way, the assembly of metal functional materials does not have to be physically bonded to the polymeric cell frame after assembly of the cell. Nevertheless, the metal bipolar plates of the assembly of metal functional materials can be positioned in intimate or very close proximity to the polymeric cell frame. They may be tightly arranged such that the joint is sealed against leakage of, for example, liquids or gases to or from the exterior of the cell. Alternatively, a suitably shaped gasket may be placed between the metal bipolar plate and the polymer cell frame to more tightly seal their joint. The close structural match of the metal bipolar plate and the polymer cell frame may minimize operational stresses on the gasket during operation of the cell.

[0037] In a first example embodiment, an electrosynthesis or electrical energy cell is provided that utilizes at least one metal bipolar plate having a "waffle" structure, or a grid-like or lattice-like arrangement of pits and lands, or ribs and spaces, or steps and voids, on a surface thereof. This provides a "metal waffle bipolar plate." The "waffle" structure resembles the structure present in a waffle iron. Preferably, but not limited to, the metal bipolar plate is a metal sheet whose surface is etched, machined, stamped, formed, depressed, or otherwise shaped into a waffle structure, i.e., a grid structure or lattice. Preferably, the waffle bipolar plate has a spring nature, thereby including, but not limited to, a "compression bipolar plate." That is, preferably, but not limited to, the waffle structure facilitates the at least one metal bipolar plate being a compression component. Preferably, but not limited to, the waffle bipolar plate is formed by precision industrial stamping, molding, and similar processes.

[0038] In another embodiment, the metal electrodes are attached directly to at least some or all of the lands of the waffle structure by metal-to-metal bonds, e.g., metal-to-metal welds, to some or all of the ribs or steps of a grid structure or lattice on the surface of the metal bipolar plate. Preferably, when the waffle is a compressed bipolar plate, said metal-to-metal bonds, e.g., metal-to-metal welds, utilize the compressive nature of the bipolar plate to exert a clamping force on the attached electrodes, compressing them against the interelectrode separator.

[0039] Preferably, the metal-to-metal bonds stabilize the structure of the bipolar plate and stop, slow or avoid distortion such as "springback". Optionally, the metal-to-metal bonds minimize variations in the physical dimensions of the bipolar plate and its flow fields, thereby enabling the use of precision industrial stamping, molding and other manufacturing processes to produce the waffle bipolar plates.

[0040] In a further example, the metallic porous transport layer is secured to some or all of the lands of the waffle structure of the metallic bipolar plate by intermetallic bonds, e.g., intermetallic welds, and the other side of the metallic porous transport layer is secured to the electrode by a different intermetallic bond, e.g., intermetallic welds. In yet a further example, the compressed metallic porous transport layer (i.e., the metallic porous transport layer compressive component) is secured to some or all of the lands of the waffle structure of the metallic bipolar plate by intermetallic bonds, e.g., intermetallic welds, and the other side of the metallic porous transport layer is secured to the electrode by a different intermetallic bond, e.g., intermetallic welds. Preferably, when the porous transport layer is a compressive component, the above intermetallic bonds, e.g., intermetallic welds, utilize the compressive nature of the porous transport layer compressive component to exert a clamping force on the attached electrode, compressing the electrode against the interelectrode separator.

[0041] Preferably, the metal-to-metal bonds stabilize the structure of the bipolar plate and stop, slow or avoid distortion such as "springback." Optionally, the metal-to-metal bonds minimize variations in the physical dimensions of the bipolar plate and its flow fields, thereby enabling the use of precision industrial stamping, molding and other manufacturing processes.

[0042] Preferably, the metal-to-metal bonds between the waffle metal bipolar plate, the metal electrodes, and where applicable the metal porous transport layer provide high electrical conductivity between these components and uniform distribution of current and voltage at the attached electrodes.

[0043] Preferably, metal-to-metal bonds between the metal waffle bipolar plates, electrodes, and, where applicable, porous transport layers provide high thermal conductivity between these components and uniform distribution of heat generated by the cell.

[0044] In a first preferred example, the peripheral area of ​​the metal waffle bipolar plate (with attached electrodes / porous transport layers) is attached to the polymer cell frame via one or more polymer-metal bonds. Preferably, but not exclusively, the thus assembled waffle structure with attached electrodes / porous transport layers has a spring (or spring) nature, thereby exerting an internal clamping force on the electrodes in the cell, compressing the electrodes against the interelectrode separator. Optionally, the thus assembled waffle structure with attached electrodes / porous transport layers is compliant, thereby displacing to correspond to a compressive force exerted by another functional component in the cell. Optionally, the one or more polymer-metal bonds between the waffle structure with attached electrodes / porous transport layers and the polymer cell frame partially or completely seal the cell body of the electrosynthesis or electrical energy cell.

[0045] In a second preferred example, the peripheral area of ​​the metal waffle bipolar plate (with attached electrodes / porous transport layer) may be mechanically held in intimate contact with an area of ​​the polymer cell frame by at least one polymer "structural positioning element" attached to the cell frame via one or more interpolymer bonds. Optionally, this intimate contact seals the joint between the waffle bipolar plate and the cell frame. Optionally, a suitable gasket may be placed between the bipolar plate and the cell frame, thereby providing improved sealing.

[0046] Optionally, the waffle structure on the metal waffle bipolar plate in one cell is structurally complementary to the waffle structure on another metal waffle bipolar plate of an adjacent cell in the cell stack, allowing the two waffle structures to interlock and fit together when compressed against each other. Preferably, such structural interlocking aids in the alignment of the cells in the cell stack and reduces the need for accurate and precise compression during and after assembly of the cell stack. Preferably, such structural interlocking provides an increased surface area for electrical contact between the cells in the cell stack.

[0047] In another embodiment, all or most of the viable seals that can be formed within the cells (i.e., "intra-cell" seals) are preferably formed during assembly of the cells. This reduces the number of reliable seals that must be formed during assembly of the cell stack to only or mainly those seals required between the cells (i.e., "inter-cell" seals). That is, the "cell body" of the electric energy or electrosynthesis cell is preferably sealed internally by its components during assembly of the cells. The "cell body" is defined herein as the portion of the cell excluding the external liquid and gas plumbing apertures and openings (i.e., "header" or "manifold" apertures or openings) that must be sealed between the cells (i.e., "inter-cell" seals) during the formation of the cell stack. Preferably, the cell body is sealed by polymer-polymer or polymer-metal bonds formed during assembly of the cells, thereby leaving only "inter-cell" liquid and / or gas connections (outside of the "cell body") formed during the assembly of the cell stack. In this way, the process of forming the cell stack can be simplified and speeded up. The need for accurate and precise compression during assembly of the cell stack may also be reduced.

[0048] In a first preferred example, the cell body is sealed by a metal-polymer bond that exists between one or more metallic bipolar plates and the polymer cell frame.

[0049] In a second preferred example, the cell body is sealed by physical contact between one or more metallic bipolar plates and the polymeric cell frame, and the metallic bipolar plates are held in intimate contact with the cell frame by polymer-to-polymer bonds between one or more polymeric structural positioning components and the polymeric cell frame. Optionally, a suitable gasket may be present between the bipolar plates and the cell frame to provide improved sealing.

[0050] Whereas direct polymer-metal bonds of the type in the first preferred example above may be pulled apart by differential expansion of the metal and polymer components during thermal or pressure cycling, seals that avoid direct polymer-metal bonds of the type in the second preferred example above may be resistant to such degradation. That is, metal-polymer seals, in which the metal and polymer components are physically separated, may provide improved durability during repeated temperature and pressure cycling, particularly when the thermal and / or pressure induced expansion of the metal and polymer cell components differ significantly.

[0051] Assembled electric energy or electrosynthetic cell architectures of the above type, which properly (pre)position the metallic and polymeric components of the cells, preferably via polymer-polymer, polymer-metal, and / or metal-metal bonds, can provide simplified and reliable formation (assembly) of cell stacks. Such proper positioning can avoid or reduce the need for precise positioning of the cells and cell components during the formation of the cell stack, thereby speeding up the process and increasing the reliability of the cell stack assembly. Preferably, the above cell architectures also provide cells that can be assembled into or within a cell stack with only moderate or low compression that does not need to be precisely applied in the face or lateral directions. Preferably, the resulting cell stack can then be operated while maintaining only moderate or low compression, thereby avoiding the need for specific or high compression during and / or after assembly of the cell stack. Moderate or low compression can preferably be created and maintained by torsional, mechanical, hydraulic (i.e., liquid) or other means that can accommodate dimensional changes in the length of the cell stack, such as may occur during repeated temperature or pressure cycles. By combining proper (pre)positioning and reduced need for compression, the above cell architecture preferably provides simplified, reliable, high speed, high volume industrial assembly of electrical energy or electrosynthesis cells into or within cell stacks without leakage or mixing of liquid or gaseous reactants and products, both after assembly and during subsequent operation.

[0052] In a first preferred embodiment, an electrical energy or electrosynthesis cell architecture is provided that includes at least one polymer cell frame, the at least one polymer cell frame being provided with: at least one polymeric interelectrode separator by or through one or more interpolymer bonds, at least one metal-functional component by or through one or more polymer-metal bonds, An electrical energy or electrosynthesis cell architecture is provided, in which the

[0053] Most preferably, the at least one metallic functional component is a metallic bipolar plate. Most preferably, the metallic bipolar plate forms part of a metal-metal bond assembly including at least one metallic bipolar plate and at least one metallic electrode, which are joined together, for example, by one or more metal-metal welds. Optionally, the metal-metal bond assembly may include at least one metallic porous transport layer located between the at least one electrode and the at least one bipolar plate, and joined to one or both of them, for example, by one or more metal-metal welds. The metal-metal bond, for example, the metal-metal weld, may provide a reduced or unchanged electrical resistance between the metallic functional materials, thereby improving the energy efficiency of the cell during operation. Most preferably, the one or more polymer-metal bonds between the polymer cell frame and the metallic bipolar plate hold the metal-metal bond assembly in place within or around the cell frame. Most preferably, the one or more polymer-metal bonds between the polymer cell frame and the metallic bipolar plate seal the polymer cell frame against the metallic bipolar plate. In one example, the metallic bipolar plate is a compression component.

[0054] Optionally, the at least one metallic functional component comprises a metallic electrode or a metallic porous transport layer. Optionally, the metallic electrode or the metallic porous transport layer forms part of a metal-metal bonded assembly that includes at least one metallic bipolar plate. Optionally, one or more polymer-metal bonds between the polymeric cell frame and the metallic electrode or between the polymeric cell frame and the metallic porous transport layer hold the metal-metal bonded assembly in place within or around the cell frame. Optionally, one or more polymer-metal bonds between the polymeric cell frame and the metallic electrode or between the polymeric cell frame and the metallic porous transport layer seal the metal-metal bonded assembly to the cell frame. In one example, the metallic porous transport layer is a compressible component and the metallic porous transport layer is a compressible component.

[0055] In a second preferred embodiment, there is provided an electrical energy or electrosynthesis cell architecture comprising at least one polymeric cell frame, the at least one polymeric cell frame being provided with: at least one polymeric interelectrode separator by or through one or more interpolymer bonds, at least one polymeric "structural positioning element" that mechanically holds at least one metallic functional element in place within or around the cell frame by one or more interpolymer bonds; An electrical energy or electrosynthesis cell architecture is provided, in which the

[0056] Most preferably, the at least one metallic functional component comprises a metallic bipolar plate. Most preferably, the metallic bipolar plate forms part of a metal-to-metal bond assembly comprising at least one metallic bipolar plate and at least one metallic electrode, which are joined together, for example, by one or more metal-to-metal welds. Optionally, the metal-to-metal bond assembly may comprise at least one metallic porous transport layer located between the at least one electrode and the at least one metallic bipolar plate, and joined to one or both of them, for example, by one or more metal-to-metal welds. The metal-to-metal bond, for example, a metal-to-metal weld, may provide a reduced or unchanged electrical resistance between the metallic functional materials, thereby improving the energy efficiency of the cell during operation. Most preferably, the polymer-to-polymer bond between the polymer cell frame and the at least one polymeric structural positioning component mechanically holds the metal-to-metal bond assembly in place within or around the cell frame. Most preferably, the metal bipolar plate of the at least one metal-to-metal bond assembly is held in intimate contact with the polymer cell frame, thereby sealing their joints. Optionally, a suitable gasket may be placed between the bipolar plate and the cell frame, thereby providing an improved seal.

[0057] Optionally, the at least one metallic functional component comprises a metallic electrode or a metallic porous transport layer. Optionally, the metallic electrode or metallic porous transport layer forms part of a metal-to-metal bond assembly that comprises at least one metallic bipolar plate in a suitable position within or around the cell frame. Optionally, the at least one polymeric structural positioning component also mechanically holds the at least one metal-to-metal bond assembly in a suitable position within or around the cell frame.

[0058] Attention is now directed to the header / manifold apertures and openings in electrosynthetic or electrical energy cells that can only be sealed when a large number of cells are integrated into a single cell stack (i.e., "cell-to-cell" sealing must be performed outside the "cell body" during stack assembly). In a further aspect, such header / manifold apertures and openings are sealed to the equivalent header / manifold apertures and openings of the next cell in the stack by one or more interpolymer bonds. That is, "cell-to-cell" interpolymer sealing can be used during formation of a cell stack to completely seal a cell whose "cell body" has already been sealed during (pre)assembly of the cells. That is, a cell can be completely sealed during formation of the cell stack by forming interpolymer bonds between the liquid and / or gas connections to and from the remaining cells of the cell stack during formation of the cell stack.

[0059] Such "cell-to-cell" polymer-to-polymer bonds can further reduce the challenge of forming a seal with accurate and precise compression during formation of the cell stack. Also, they can provide a more reliable seal that is less dependent on maintaining a consistent high compression across the cell stack. In contrast, conventional cell stacks are essentially entirely dependent on high compression to form and maintain such a seal.

[0060] Any polymer-polymer bonding technique can be used to form the required bonds, including any of the polymer-polymer bonding techniques described or enumerated herein.

[0061] In a particularly preferred example, such interpolymer bonds are formed on each cell by patterning and placing resistive metal wire or electrical circuitry around the polymer header / manifold aperture to be sealed. After the cells are stacked and compressed to the required degree for cell assembly, electrical current is passed through each circuit present, causing heating of each circuit and resulting melting and fusing of the polymeric material of adjacent cells around the circuit. The resulting cell stack architecture includes cells stacked and bonded via interpolymer bonds incorporating resistive wire and / or electrical circuitry around the header / manifold aperture.

[0062] In another preferred example, a gasket, such as a molded sheet or ring of rubber, is placed around a first portion of the polymeric area to be sealed, followed by the type of interpolymer seal described above in a second portion of the polymeric area to be sealed. The gasket can provide an additional long-term measure of protection against leakage, which can be particularly useful when structurally complex interpolymer bonds are required. The resulting cell stack architecture includes cells stacked and bonded around the header / manifold apertures, with gaskets near the interpolymer bonds, via interpolymer bonds incorporating resistive wires and / or electrical circuits.

[0063] In other instances, the required interpolymer bonds may be too complex or demanding to reliably seal, in which case one or more gaskets may be used and relied upon. The resulting cell stack architecture includes cells stacked with gaskets around the header / manifold apertures, and compression of the stack maintains the gasket seal.

[0064] Preferably, the above sealing architectures provide for simplified and reliable assembly of components and cells into or within cell stacks without leakage or mixing of liquid or gaseous reactants and products, both after assembly and during subsequent operation. Preferably, they also provide for high speed, high volume industrial assembly of electrosynthesis or electrical energy cell stacks.

[0065] In certain example embodiments, the overall compressive pressure applied to the cell stack during assembly and thereafter (e.g., during electrochemical operation) is greater than 0.01 bar, greater than 0.02 bar, greater than 0.03 bar, greater than 0.04 bar, greater than 0.05 bar, greater than 0.075 bar, greater than 0.1 bar, greater than 0.2 bar, greater than 0.3 bar, greater than 0.5 bar, greater than 0.75 bar, greater than 1 bar, greater than 2 bar, greater than 3 bar, greater than 4 bar, greater than 5 bar, greater than 10 bar, greater than 15 bar, greater than 20 bar, greater than 30 bar, greater than 40 bar, greater than 50 bar, or greater than 100 bar.

[0066] In various other example aspects, embodiments relate to reliable and successful assembly of electric energy or electrosynthesis cells and cell stacks when low tolerance components are used, and the resulting cells and cell stacks preferably do not leak or mix with liquid or gaseous reactants and products, both after assembly and during subsequent operation.

[0067] Preferably, the above types of metal-polymer or interpolymer bonds incorporate one or more "tolerance compensating features" that accommodate the low tolerances and high variability in the dimensions of the cell components, including the polymer cell frame, interelectrode separator, electrodes, porous transport layers, or bipolar plates. Tolerance compensating features include structures designed to accommodate variability in the components being joined. They include channels, grooves, slots, tongues, and other structural features that are slightly oversized or undersized to accommodate variations in the amount of material released during joining. Some tolerance compensating features may be incorporated in the form of positive engagement components, such as tongues and grooves, locating pins, and holes.

[0068] In various other example aspects, embodiments relate to polymer-polymer, polymer-metal, and metal-metal bonds that may be used in the cell and cell stack architectures and techniques described above. In some examples, such bonds incorporate one or more "tolerance compensating features" that accommodate the low tolerances and high variability in dimensions of cell components, including polymer cell frames, interelectrode separators, electrodes, compression components, porous transport layers, or bipolar plates. Preferably, the following bonds may incorporate tolerance compensating features: (1) "Sealed Wire Welding" Joint (2) "Ridge polymer-metal" bonding can be used, but is not limited to this.

[0069] In various other example aspects, embodiments relate to polymer-polymer and polymer-metal bonds that may be used in the above cell and cell stack architectures and techniques.

[0070] Preferably, the following polymer-metal joints may be used in the above cell and cell stack architectures and techniques, but are not limited to these: (1) "Continuous edge heat staked" joints (2) "Textured metal-polymer" bonding, (3) “Roll-formed” joints.

[0071] Other preferred embodiment examples include, but are not limited to, polymer-metal and polymer-polymer bonds involving: (1) Chemical bonding with or without chemical adhesion promoting materials, including the application of: i. Various types of adhesives and glues, including but not limited to: 1. Glues by chemical composition, including epoxy glue, polyurethane glue, polyimide glue, cyanoacrylate glue, polyvinyl acetate glue; 2. Adhesives by physical form, including adhesive pastes, adhesive gums, adhesive films, adhesive cements, adhesive resins, adhesive binders, elastomeric adhesives, wet adhesives; 3. Adhesives by classification, including contact adhesives, reactive adhesives, single-component reactive adhesives, two-component or multi-component reactive adhesives, hot melt adhesives, pressure sensitive adhesives, thermosetting adhesives; 4. Adhesives by their ability to withstand loads, including structural adhesives, non-structural adhesives, and semi-structural adhesives; (2) Dissolution and rematerialization of polymers, including but not limited to: i. Solvent welding; (3) Melting or softening of polymers, with or without wetting agents to promote polymer flow, including but not limited to: i. Heat welding, ii. Hot plate or platen welding; iii. Ultrasonic or vibration welding; iv. Laser welding or laser beam welding; v. Hot air welding, vi. Spin welding, vii. Friction welding, viii. Frequency, high frequency, or radio frequency welding; ix. Infrared or non-contact welding; x.Speed ​​tip welding, xi. Extrusion welding; xii. Contact welding, xiii. Induction welding; and xiv.Injection welding.

[0072] In various other example aspects, embodiments relate to metal-to-metal joints that may be used in the above cell and cell stack architectures and techniques. Example preferred embodiments include metal-to-metal joints that include, but are not limited to: (1) Mechanical bonds, including but not limited to bonds formed by: i. Riveting, ii. Caulking; iii. bolting; iv. Shrink fit, v. Bending; (2) Chemical bonds, including but not limited to bonds formed by: i. Bonding, including bonding of metals with glues, including conductive glues; (3) Metallurgical bonds, including but not limited to bonds formed by: i. Fusion welding, including: 1. Electric energy: arc welding, electron beam welding, 2. Chemical energy: gas welding, 3. Light energy: laser welding; ii. Pressure welding, including: 1. Electric energy: resistance welding (including resistance spot welding, projection welding, seam welding, upset welding, and flash welding); 2. Chemical energy: explosive welding, 3. Mechanical energy: cold welding, friction welding, friction stir welding, ultrasonic welding, diffusion welding; iii. Brazing / soldering, including: 1. Electric energy: induction brazing, soft soldering, soldering, 2. Chemical energy: torch brazing, flame brazing, 3. Light energy: light beam brazing, laser brazing, 4. "Soft soldering", 5. "Hard soldering."

[0073] Preferably, but not limited to, the liquid electrolyte used in the example embodiments comprises a hydroxide salt and has a pH of at least 10. Optionally, the liquid electrolyte used in the example embodiments has a pH of less than 10.

[0074] Preferably, the cells and cell stacks having the above characteristics are electrical energy or electrosynthesis cells or cell stacks such as: (i) hydrogen-oxygen fuel cells, including polymer electrolyte membrane (PEM) fuel cells or alkaline fuel cells; (ii) direct alcohol fuel cells, including direct methanol or direct ethanol fuel cells; (iii) phosphoric acid fuel cells; or (iv) ammonia fuel cells.

[0075] Preferably, the cells and cell stacks having the above characteristics are electrosynthesis cells or cell stacks such as (i) water electrolysers, (ii) chlor-alkali electrolysers, (iii) nitrogen reduction cells for ammonia production, or (iv) CO2 electrolysers (including integrated carbon capture and CO2 electrolysers).

[0076] Preferably, the cells and cell stacks having the above characteristics are capillary-powered electrical energy or electrosynthesis cells or cell stacks of the type described in International Publication Nos. WO 2022056603, WO 2022056604, WO 2022056605, and WO 2022056606, which are incorporated herein by reference.

[0077] Exemplary embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which: Various example embodiments will become apparent from the following description, given by way of example only of at least one preferred but non-limiting embodiment, described in conjunction with the accompanying drawings, in which: [Brief description of the drawings]

[0078] [Figure 1] 1 shows a schematic of the assembly of a preferred embodiment of a cell; [Diagram 2]1 illustrates a schematic of an assembly of a cell according to another preferred embodiment; [Diagram 3] 13A-13C show schematic diagrams of the assembly of a further preferred embodiment example cell; [Figure 4] 1 illustrates the attachment of an exemplary electrode to an exemplary waffle bipolar plate via metal-to-metal bonding. [Diagram 5] 1 illustrates an exemplary cell stack assembly. [Figure 6] FIG. 1 shows how two cells in a cell stack can be sealed using a heating wire. [Figure 7] 13A-13C are schematic diagrams illustrating a cell and cell stack assembly of a second example embodiment in cross-sectional form, with the metal components physically separated from the polymeric components; [Figure 8] 1A-1C are schematic diagrams illustrating the formation of a preferred polymer-metal bond incorporating a tolerance compensation feature known as a "seal wire weld" bond. [Figure 9] 1 shows a schematic cross-sectional view of a preferred polymer-metal joint incorporating a tolerance compensating feature known as a "ridge polymer-metal" joint. [Figure 10] 1 shows a schematic cross-sectional view of the formation of a preferred polymer-metal bond known as "continuous edge heat staking." [Figure 11] 1 shows a cross-sectional schematic illustrating the formation of a preferred polymer-metal bond involving the use of laser welding. [Figure 12] 1 shows a schematic cross-sectional view of the formation of a preferred polymer-metal bond, known as a "roll-formed" bond. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0079] The following modes, features, or aspects, presented merely as examples, are described to provide a more accurate understanding of the preferred embodiments or subject matter of the embodiments.

[0080] definition "Reactants" refer to chemicals consumed during an electrochemical reaction.

[0081] "Product" refers to a chemical produced during an electrochemical reaction.

[0082] An "electrolyte" is a liquid containing dissolved ions that has the property of conducting electricity.

[0083] "Room temperature" is defined as 21°C.

[0084] In the context of manufactured parts, the term "tolerance" refers to the amount of allowable variation in the dimensions of the part. A "high" tolerance correlates with high precision, i.e., it indicates a small variation in the dimensions of the manufactured part. A "low" tolerance correlates with low precision, i.e., it indicates a large variation in the dimensions of the manufactured part.

[0085] In the context of this specification, the terms "join," "joined," or "joins" refer to a secure physical bond, such as welding, fusing, bonding, adhering, blending, mixing, or merging, of two structures. For example, a "polymer-polymer" bond refers to a secure physical bond between two polymeric structures. A "polymer-metal" bond refers to a secure physical bond between a polymeric structure and a metal structure.

[0086] A "liquid-gas" cell is defined as an electrochemical cell that has at least one liquid phase reactant or product and at least one gas phase reactant or product.

[0087] An "electrical energy cell" is an electrochemical cell that, during operation, produces electrical power continuously or sequentially for an indefinite period of time for use outside the cell. An electrical energy cell may require a constant external supply of reactants during operation. Also, products of the electrochemical reaction may be constantly removed from such a cell during operation. An electrical energy cell may be a liquid-gas cell. An example of an electrical energy cell is a hydrogen-oxygen fuel cell. This example is also a liquid-gas cell.

[0088] An "electrosynthesis cell" is an electrochemical cell that continuously or sequentially produces one or more chemicals during operation for an indefinite period of time for use outside the cell. The chemicals may be in gas, liquid, or solid form. Like an electric energy cell, an electrosynthesis cell may also require a constant supply of reactants and a constant removal of products during operation. In general, an electrosynthesis cell may also require a constant input of electric energy during operation. An electrosynthesis cell may be a liquid-gas cell. An example of an electrosynthesis cell is a water electrolysis cell. This example is also a liquid-gas cell.

[0089] Electrical energy cells and electrosynthesis cells differ from other types of electrochemical cells, such as batteries, sensors, etc., in that they do not incorporate within the cell body all / part of the reactants they need to operate, nor all / part of the products they produce during operation. Instead, they are constantly taken in or taken out of the cell during operation. For example, electrical energy cells are distinguished from galvanic cells in that galvanic cells store reactants and products within the cell body. Unlike batteries, electrical energy cells do not store chemical or electrical energy within them. Similarly, some electrochemical sensors consume reactants and produce limited amounts of products during sensing operations, but all / part of these are stored within the cell body itself.

[0090] An "interelectrode separator" is defined as a structure in an electric energy cell or an electric synthesis cell that is permeable to ions but largely impermeable to gases and that is disposed between the electrodes in the electrosynthesis cell or electric energy cell to prevent gases from crossing over from one of the constituent half-cells to the other half-cell. Examples of "interelectrode separators" include ion-permeable membranes (e.g., Nafion 117 and Nafion 115 from Du Pont Nemours), diaphragms (e.g., Zirfon PERL from Agfa), fabrics (e.g., various asbestos fabrics used in the past), or similar structures. The term "interelectrode separator" includes interelectrode porous capillary separators and is defined as described in WO2022056603, WO2022056604, WO2022056605, and WO2022056606, which are incorporated herein by reference.

[0091] An "electrode" is an electrically conductive structure, typically metallic, within an electrosynthetic or electrical energy cell where electrons are converted into ions or vice versa. An electrode can generally be an anode or a cathode during operation of the cell.

[0092] A "porous transport layer" refers to a porous layer that contains voids through which gas or liquid passes during operation of the electrosynthesis cell or electrical energy cell. The porous transport layer may be conductive and / or metallic and / or may be located near or against the electrodes. The porous transport layer may also be located between the electrodes and the bipolar plate. That is, the porous transport layer may be a conductive, often metallic, structure that is porous to liquid and / or gas fluids and is located between the electrodes and their bipolar plates. The porous transport layer may provide electrical connection between the electrodes and the bipolar plate while allowing the movement of liquid or gas to or from the electrodes.

[0093] A "bipolar plate" is a conductive plate (usually metal) located outside an electrosynthesis cell or electrical energy cell, or between electrosynthesis cells or electrical energy cells in a cell stack. The term "bipolar" refers to the fact that in a cell stack, a voltage applied to a bipolar plate can be used in the anodic reaction on the one hand and in the cathodic reaction on the other hand. The main function of a bipolar plate is to accumulate the current and distribute it evenly from one cell to the next.

[0094] "Flow field" refers to a pattern of pits and lands, or ribs and spaces, or steps and voids, etched, machined, stamped, sunk, or otherwise formed into the face of a bipolar plate. A common flow field is a serpentine flow field, which has one or more channels in a serpentine arrangement sunk into the face.

[0095] A "waffle" flow field refers to a pattern of pits and lands, or ribs and spaces, or steps and voids, much like that of a waffle iron.

[0096] A "waffle bipolar plate" is a bipolar plate having a "waffle" flow field present on the surface, i.e., the flow field resembles that of a waffle iron. It should be understood that the term "waffle bipolar plate" may be used herein to describe any bipolar plate that can simultaneously function as a porous transport layer. That is, the term "waffle bipolar plate" is also used herein to describe any bipolar plate whose surface includes voids through which gas can pass during operation of the electrosynthesis cell or electrical energy cell. In other words, the term "waffle bipolar plate" may be used herein to describe any bipolar plate that provides the type of porosity also found in the porous transport layer.

[0097] A "cell stack" or "stack" refers to a group of electrochemical cells stacked laterally one on top of the other such that the electrochemical cells are electrically connected in series. A cell stack may be designed to accumulate the reactants and products involved in its constituent cells into a single external product and / or reactant stream that is more easily managed than multiple smaller streams.

[0098] A "cell stack" may take the form of a "filter press" arrangement, which is defined as a cell stack in which cells are compressed together between end plates during assembly and / or operation.

[0099] "End Plate" is defined as a rigid, essentially incompressible, essentially flat structure used at the ends of a "filter press" cell stack and between which the cells in the cell stack are compressed.

[0100] An assembled cell is defined as being "internal compressed" when a clamping force is applied to at least one electrode in the assembled cell, thereby compressing the electrode against the interelectrode separator. In a preferred embodiment, the individual cells are preferably assembled before being integrated into a cell stack. Preferably, such assembled cells are "internal compressed", meaning that a clamping force is already applied to at least one electrode in the assembled cell, thereby compressing the electrode against the interelectrode separator. The integration of such (pre-)assembled cells into a cell stack can be accomplished much more easily and quickly than if the cells were only assembled during the cell stack formation process itself, as may be conventionally done for electrosynthesis or electric energy filter press cell stacks. Also, the need for accurate and precise compression of the cell stack during and after the formation of the cell stack can be reduced by the fact that the cells in the stack are already "internal compressed".

[0101] "Header aperture" or "header opening" means an exterior aperture or opening in an individual cell for conveying a fluid, either liquid or gas, into or out of the cell. When combined with equivalent header apertures in other cells in a stack, the header aperture or opening forms a corresponding "header" in the cell stack.

[0102] "Header" means a channel, tube, chamber, or trough formed by a combination of header apertures or openings in individual cells in a cell stack for carrying a fluid, either liquid or gas, throughout the thickness of the cell stack. A header is formed when a set of equivalent header apertures or openings in multiple cells are aligned and sealed when the cells are compressed together to form the cell stack.

[0103] A "manifold" is one or more pipes, tubes, chambers, or channels that have multiple openings for carrying fluids. In a cell stack, a header can also be a manifold.

[0104] The term "cell body" is defined as that portion of a cell outside of the external openings for conveying fluids, either liquid or gas, into or out of the cell, i.e., it is that portion of a cell excluding the header / manifold apertures or openings, i.e., it is that portion of a cell that can be sealed by an "intra-cell" seal (i.e., a seal that only involves and can only occur internal to a single cell), and excluding that portion of a cell that can only be sealed by an "inter-cell" seal (i.e., a seal that necessarily involves more than one cell).

[0105] A cell is "stackable" if it is designed to be placed in a cell stack. For example, in the case of a filter press type cell stack, it may include liquid or gas piping header apertures or openings that align with equivalent apertures or openings in other cells in the stack to form headers or manifolds. In a non-limiting example of a filter press cell stack, the cells are substantially flat and are compressed against each other between the end plates during its assembly and / or operation.

[0106] A "structural positioning component" is defined as a polymeric structure within an electrosynthesis cell or electrical energy cell that, when attached to the polymeric cell frame, mechanically holds a physically separate metal structure in the appropriate position within or around the cell and / or cell frame.

[0107] A "compression component" or "compression element" in a cell is defined as a spring structure that, when properly positioned in the cell, exerts a clamping force on at least one of the electrodes, thereby compressing that electrode against the interelectrode separator. Preferably, the spring action is created within at least one of the metallic bipolar plate or metallic porous transport layer. Optionally, the spring action may be created within at least one of the metallic electrodes.

[0108] A "bipolar plate compression component" refers to a bipolar plate that also has a compression function; that is, a spring or spring structure that, when properly positioned within an assembled cell, exerts a clamping force on the associated electrode, thereby compressing the electrode against the interelectrode separator. It should be understood that such spring action is preferably designed into the bipolar plate compression component such that the bipolar plate compression component exerts a specific, pre-determined clamping force on the electrode within a relatively narrow clamping force range. The bipolar plate compression component does not exert a clamping force merely accidentally, e.g., by "springback", or in an uncontrollable or unrepeatable manner. Preferably, the clamping force within the cell is created, in whole or in part, by the stiffness of (1) the polymer-metal bond between the bipolar plate compression component and the polymer cell frame, or (2) the polymer-polymer bond between the "polymeric structural positioning" element and the polymer cell frame.

[0109] A "porous transport layer compression component" or "spring porous transport layer" refers to a porous transport layer that also has a compression function. That is, the porous transport layer is a spring or spring structure that, when properly positioned in an assembled cell, exerts a clamping force on the associated electrode, thereby compressing the electrode against the interelectrode separator. It should be understood that such spring action is preferably designed into the porous transport layer compression component such that the porous transport layer compression component exerts a specific, pre-determined clamping force on the electrode within a relatively narrow clamping force range. The porous transport layer compression component does not exert a clamping force merely by chance or in an uncontrollable or unrepeatable manner. Preferably, the clamping force within the cell is created, in whole or in part, by the stiffness of (1) the polymer-metal bond between the bipolar plate compression component and the polymer cell frame, or (2) the polymer-polymer bond between the "polymeric structure positioning" element and the polymer cell frame.

[0110] Different compression components may be provided, such as a "metal bipolar plate compression component," a "metal porous transport layer compression component," and / or a "metal electrode compression component." Such structures are metallic structures that are spring structures or spring structures that, when properly positioned within the assembled cell, exert a clamping force on the associated electrode, thereby compressing the electrode against the interelectrode separator.

[0111] A "compliant component" or "compliant element" in a cell is defined as a compressible structure that, when properly positioned in the cell, responds to a compressive force and displaces to distribute the compressive force evenly. Preferably, the compliant action is created within at least one of the metallic bipolar plate or the metallic porous transport layer. Optionally, the compliant action may be created within at least one metallic electrode. A "bipolar plate compliant component" refers to a bipolar plate that also has a compliant function. A "porous transport layer compliant component" refers to a porous transport layer that also has a compliant function. That is, different compliant components may be provided, for example, a "metallic bipolar plate compliant component", a "metallic porous transport layer compliant component", and / or a "metallic electrode compliant component".

[0112] "Metal-to-metal weld" is defined herein as any form of metallurgical intermetallic joining that may be considered to involve welding, including, but not limited to, fusion welding and pressure welding.

[0113] A "gasket" is defined as a molded sheet or ring of rubber or other resilient material that seals the joint between two surfaces that are not physically joined.

[0114] "Tolerance compensating features" are defined as structures designed to accommodate variability in the components being joined. Tolerance compensating features include, but are not limited to, channels, grooves, slots, tongues, and other structural features that are slightly oversized or slightly undersized to accommodate variations in the amount of material that flows during joining.

[0115] "Pressure-fitting engagement components" refer to complementary structures that facilitate engagement between two surfaces, such as tongue and grooves, locating pins, and holes. Some pressure-fitting engagement components may include one or more tolerance compensation features.

[0116] Preferred Embodiments The inventors have developed a new electrosynthetic or electrical energy cell architecture that simplifies the process of reliably assembling cells into cell stacks and maintaining them during subsequent operation. The cell includes a polymeric cell frame incorporating functional materials within or around the interelectrode separator, electrodes, porous transport layers, and bipolar plates. The individual functional materials may be attached to the cell frame by interpolymer or polymer-metal bonds. As an example, one or more polymeric functional materials may be attached to the polymeric cell frame via one or more interpolymer bonds. For example, a polymeric interelectrode separator may be attached to the polymeric cell frame via one or more interpolymer bonds. The interpolymer bonds may seal the joint between the polymeric interelectrode separator and the polymeric cell frame against leakage of gas from one side of the interelectrode separator to the other side, for example across the thickness of the interelectrode separator. In another example, one or more metal functional materials may be attached to the polymeric cell frame via one or more metal-polymer bonds. For example, a metallic bipolar plate may be attached to the cell frame via one or more polymer-metal bonds that can seal the joint between the metallic bipolar plate and the polymer cell frame against leakage of, for example, liquids or gases to or from the exterior of the cell.

[0117] Additionally, some or all of the metallic functional materials of each half-cell within the entire cell may be attached to one another via one or more intermetallic bonds, e.g., intermetallic welds. For example, the metallic electrodes and metallic bipolar plates, which comprise the metallic components of a single half-cell, may be attached to one another via one or more intermetallic bonds, e.g., intermetallic welds. In the alternative, the metallic electrodes, metallic porous transport layers, and metallic bipolar plates, which comprise the metallic components of a single half-cell, may be attached to one another via one or more intermetallic bonds, e.g., intermetallic welds. Such intermetallic bonds, e.g., intermetallic welds, may thereby result in a single metallic component to be handled during assembly of the cell, simplifying assembly of the cell. Also, such intermetallic bonding processes may be performed separately and independently from assembly of the cell, further simplifying assembly of the cell.

[0118] One or more of the metallic functional materials thus attached to one another may be attached to the polymeric cell frame via one or more metal-polymer bonds. For example, the bipolar plate in one of the aforementioned metal-to-metal bond assemblies may be attached to the polymeric cell frame by one or more metal-polymer bonds. The metal-polymer bonds may seal the joint between the metallic bipolar plate and the polymeric cell frame against leakage of, for example, liquids or gases to or from the exterior of the cell.

[0119] In an alternative embodiment, a polymeric "structural positioning component" can be attached to the polymeric cell frame via one or more interpolymer bonds, thereby structurally restraining some or all of the metal functional components in the appropriate position within or around the cell frame. The structural positioning component is a polymeric structure that, when attached to the polymeric cell frame, mechanically holds one or more physically separate metal components in the appropriate position within or around the cell frame. In such a case, the metal functional components may not be physically bonded to the polymeric cell frame. Nevertheless, some of the metal functional components, such as the bipolar plates, may be placed tightly or in close proximity to the polymeric cell frame. These may be tightly placed such that the joints are sealed against leakage of, for example, liquids or gases to or from the exterior of the cell. Alternatively, a suitably shaped gasket may be placed between the metal bipolar plates and the polymeric cell frame to more tightly seal their joints. The close structural match of the metal bipolar plates and the polymeric cell frame may minimize the operating stresses on the gaskets during operation of the cell.

[0120] This type of cell architecture can also be partially self-sealing. For example, due to the above sealing properties, the "cell body" of such an electric energy or electrosynthesis cell architecture may be sealed internally by its components, thereby reducing the need to create a reliable seal by accurately and precisely compressing the cell stack during and after assembly of the cell stack. The "cell body" is the part of the cell excluding the external liquid and gas plumbing apertures and openings, i.e., it is the part of the cell outside the "header" or "manifold" apertures or openings. In other words, the "cell body" is the part of the cell that can be sealed by an "intra-cell" seal (i.e., a seal involving and possibly caused by cell components within a single cell), excluding the part of the cell that can only be sealed by an "inter-cell" seal (i.e., a seal that necessarily spans two or more cells). Preferably, the cell body is effectively sealed by the presence of the cell components and the polymer-polymer or polymer-metal bonds that are present, leaving only the "inter-cell" liquid and / or gas connections that are created during assembly of the cell stack. That is, the cell body may be sealed by a metal-polymer bond present between one or more metallic bipolar plates and the polymer cell frame. Alternatively, the cell body may be sealed by physical contact between one or more metallic bipolar plates and the polymer cell frame, where the metallic bipolar plates are held intimately to the cell frame by a polymer-polymer bond between one or more polymeric structural positioning components and the polymer cell frame. Optionally, a suitable gasket may be present between the bipolar plate and the cell frame to provide improved sealing. The former type of direct polymer-metal bond may be pulled apart by forces caused by differential expansion of the metallic and polymeric components during thermal or pressure cycling, whereas the latter type of seal avoiding direct polymer-metal bond may be resistant to such degradation.That is, metal-polymer seals, in which the metal and polymer components are physically separated, can provide improved durability during repeated temperature and pressure cycling, especially when the thermal and / or pressure induced expansion of the metal and polymer cell components differ significantly.

[0121] Additionally, electrical energy or electrosynthesis cell architectures of the above types may be "internal compressed," thereby reducing the need to precisely and precisely compress the cell stack during and after assembly of the cell stack, i.e., the assembled cell architecture may exert a clamping force on at least one of the electrodes, thereby compressing that electrode against the inter-electrode separator.

[0122] This can be accomplished by incorporating into the cell architecture at least one compression component (e.g., a spring component or element) that exerts a clamping force on at least one of the electrodes (e.g., the first electrode or the second electrode), compressing that electrode against the interelectrode separator. The at least one compression component, e.g., the spring component or element, may include a metal bipolar plate or a metal porous transport layer. Alternatively, but less preferably, the at least one compression component may include a metal electrode.

[0123] Preferably, the clamping force exerted internally within the assembled cell by the compression components on the electrodes, compressing the electrodes against the inter-electrode separator, is greater than 0.01 bar, greater than 0.02 bar, greater than 0.03 bar, greater than 0.04 bar, greater than 0.05 bar, greater than 0.075 bar, greater than 0.1 bar, greater than 0.2 bar, greater than 0.3 bar, greater than 0.5 bar, greater than 0.75 bar, greater than 1 bar, greater than 2 bar, greater than 3 bar, greater than 4 bar, greater than 5 bar, greater than 10 bar, greater than 15 bar, or greater than 20 bar.

[0124] The compression applied internally within the assembled cells may preferably be greater than 0.01 bar, greater than 0.02 bar, greater than 0.03 bar, greater than 0.04 bar, greater than 0.05 bar, greater than 0.075 bar, greater than 0.1 bar, greater than 0.2 bar, greater than 0.3 bar, greater than 0.5 bar, greater than 0.75 bar, greater than 1 bar, greater than 2 bar, greater than 3 bar, greater than 4 bar, greater than 5 bar, greater than 10 bar, greater than 15 bar, or greater than 20 bar.

[0125] To mediate and evenly distribute the internal compressive force, the cell may further incorporate at least one compliant component. Such a compliant component may be uniformly displaced to accommodate the compressive force exerted by the at least one compressive component. The compliant component may be a metallic bipolar plate, a metallic porous transport layer, or a metallic electrode.

[0126] Electrical energy or electrosynthetic cell architectures of the above type, which properly position the metal and polymer components in the (pre)assembled cells via polymer-polymer, polymer-metal, and / or metal-metal bonds, can provide simplified and reliable assembly of cell stacks. Such proper positioning in the assembled cells can avoid or reduce the need to precisely position the cell components in the cell stack during the formation of the cell stack. The above cell architectures can also provide assembled cells that are integrated into or within the cell stack with only moderate or low compression that does not need to be precisely applied in the face or lateral directions. The resulting cell stack can then be operated while maintaining only moderate or low compression, thereby avoiding the need for specific or high compression after the cell stack is formed. Moderate or low compression can be created and maintained by torsional, mechanical, hydraulic (i.e., liquid), or other means that can accommodate dimensional changes in the length of the cell stack, such as may occur during repeated temperature or pressure cycles. Thus, by combining appropriate arrangements within the assembled cells with reduced need for compression, the above cell architecture can provide simplified, reliable, high speed, high volume industrial formation of electrical energy or electrosynthesis cell stacks, particularly filter press cell stacks, without leakage or intermixing of liquid or gaseous reactants and products, both after assembly and during subsequent operation.

[0127] Preferred embodiment: First preferred embodiment cell architecture In a first preferred non-limiting embodiment, an electrical energy or electrosynthesis cell architecture includes at least one polymeric cell frame, the at least one polymeric cell frame having: at least one polymeric interelectrode separator by or through one or more interpolymer bonds, at least one metal-functional component by or through one or more polymer-metal bonds, An electrical energy or electrosynthesis cell architecture is provided, in which the

[0128] At least one metallic functional component may be a metallic bipolar plate. The metallic bipolar plate may form part of a metal-metal bonded assembly (e.g., a metal-metal welded assembly) including, for example, at least one metallic bipolar plate, at least one metallic electrode (e.g., cathode or anode), and optionally at least one metallic porous transport layer. One or more polymer-metal bonds between the polymer cell frame and the metallic bipolar plate may hold the metal-metal bonded assembly in place within or around the cell frame. The presence of one or more polymer-metal bonds may seal the polymer cell frame to the metallic bipolar plate.

[0129] The at least one metallic functional component may alternatively comprise a metallic electrode or a metallic porous transport layer. Also, the at least one metallic electrode or the at least one metallic porous transport layer may form part of a metal-metal bonded assembly (e.g., a metal-metal welded assembly) that includes at least one metallic bipolar plate. Optionally, one or more polymer-metal bonds between the polymer cell frame and the metallic electrode or between the polymer cell frame and the metallic porous transport layer can hold the metal-metal bonded assembly in place within or around the cell frame.

[0130] FIG. 1 shows a schematic of the components and assembly of a first preferred embodiment example electric energy or electrosynthesis cell 10. Starting from the top left of FIG. 1 along row A, the cell includes a polymeric cell frame 11 with a relatively large open window (i.e., window cutout) in the center, and an inter-electrode separator 12. In one example, the substrate of the inter-electrode separator is a polymeric material, i.e., the inter-electrode separator is a polymeric inter-electrode separator. Preferably, the substrate of the inter-electrode separator includes, but is not limited to, the same or substantially similar polymeric material as the substrate of the cell frame 11 structure. The window cutout is preferably a space devoid of material. However, in some examples, material may be present, such as ribs or supports of polymeric material, which may be present and may extend into a portion of the cutout window area for structural integrity of the polymeric cell frame or for support of other components.

[0131] Column B of FIG. 1 shows an inter-electrode separator 12 (forming assembly 112) bonded to cell frame 11 by polymer-polymer bonding around the periphery of a window cut out in cell frame 12. Inter-electrode separator 12 is bonded to polymer cell frame 11 and placed within the window cutout. Other components in the exploded view shown along column B of FIG. 1 include a first electrode 13 and a second electrode 14 (i.e., electrodes 13, 14 or two electrodes 13, 14), which may be porous and metal-based or entirely metallic. Depending on the embodiment, first electrode 13 may be an anode or a cathode, and second electrode 14 may be an anode or a cathode. Electrodes 13 and 14 are pre-cut to fit the window in cell frame 11, i.e., electrodes 13 and 14 are placed within the polymer cell frame. Outside and adjacent to the electrodes 13 and 14 are first and second compression elements 15 and 16 (i.e., compression elements 15, 16), which in this particular non-limiting example are conductive metallic porous transport layers and also perform a compression (e.g., spring) function. Compression element 15 is positioned adjacent to, next to, or against the first electrode 13, on the side opposite the interelectrode separator 12. Compression element 16 is positioned adjacent to, next to, or against the second electrode 14, on the side opposite the interelectrode separator 12. The compression elements 15, 16 (also referred to in this example as metallic porous transport layer compression elements 15, 16) are also cut to fit the cut-out windows in the cell frame 11. Outside the exploded view in row B of Figure 1 are a first metallic bipolar plate 17 and a second metallic bipolar plate 18 (i.e., metallic bipolar plates 17, 18). Metallic bipolar plates 17, 18 are pre-cut to be larger than the cut-out window in polymeric cell frame 11 and therefore overlap the outside of polymeric cell frame 11 (including overlap at the top, bottom, and side edges of polymeric cell frame 11).

[0132] Column C of Figure 1 shows the components at the next stage of assembly: electrodes 13 and 14 are placed in window cutouts in cell frame 11 and in intimate contact with either side of inter-electrode separator 12 which is bonded to cell frame 11. The assembly of cell frame 11, inter-electrode separator 12, and electrodes 13 and 14 is labeled assembly 1112.

[0133] As illustrated in column C of FIG. 1 , compression components 15, 16 (e.g., spring porous transport layers 15, 16) are about to be inserted into the cut-out windows of cell frame 11. Metal bipolar plates 17 and 18 are then securely attached by polymer-metal bonding to the uncovered exposed polymer surfaces at the front and back sides of cell frame 11, respectively, and around the top, bottom, and both sides of cell frame 11, thereby sealing the “cell body” of cell 10. Upon attaching metal bipolar plates 17 and 18 to polymer cell frame 11 by polymer-metal bonding, compression components 15, 16 (e.g., spring porous transport layers 15 and 16) located between metal bipolar plates 17 and 18 and electrodes 13 and 14 exert an inward clamping force on electrodes 13 and 14, respectively, thereby tightly compressing electrodes 13 and 14 against both sides of interelectrode separator 12.

[0134] 1 thus illustrates a non-limiting example of an electrical energy or electrosynthesis cell 10 including a polymeric cell frame 11, a first electrode 13, and a second electrode 14. An inter-electrode separator 12 is disposed between the first electrode 13 and the second electrode 14. A (first) compressive component 15, which is a metallic porous transport layer compressive component 15, is disposed adjacent to the first electrode 13 on the side opposite the inter-electrode separator 12. A (first) metallic bipolar plate 17 is disposed adjacent to the (first) compressive component 15 on the side opposite the first electrode 13. In the illustrated example (which may not be necessary in various other examples), a second compression component 16, which is a second metallic porous transport layer compression component 16, is positioned adjacent, next to, or abutting the second electrode 14 on the side opposite the inter-electrode separator 12, and a second metallic bipolar plate 18 is positioned adjacent to the second compression component 16 on the side opposite the second electrode 14. Optionally, at least one polymeric structural positioning component (not shown in FIG. 1 ) positions the metallic bipolar plate 17 relative to the polymeric cell frame 11.

[0135] In one alternative, the inter-electrode separator forms part of or is integrally formed as part of the polymer cell frame and, while being a polymeric inter-electrode separator, is still disposed between the first and second electrodes.

[0136] 1 illustrates a case where both compression components 15 and 16 (e.g., metallic porous transport layer compression components 15 and 16) have a compression function. However, it should be understood that an alternative preferred example includes one of compression components 15 and 16 (e.g., one of porous transport layers 15 and 16) having a compression function, such as the first compression component 15 (i.e., being a metallic porous transport layer compression component), and the other having a compliant function, such as the second porous transport layer 16 (i.e., being a metallic porous transport layer compliant component).

[0137] The bottom right image of FIG.

[0138] As illustrated in FIG. 1, the following important points pertain to cell 10: (1) The polymer-metal bond between the metal bipolar plates 17 and 18 and the uncovered exposed polymer surfaces on both sides of the cell frame 11 causes the compression components 15 and 16 (e.g., spring porous transport layers 15 and 16) to be compressed against the electrodes 13 and 14, respectively. That is, the architecture of the cell 10 causes the cell 10 to be internally compressed. This compression is generally achieved more easily, more quickly, more reliably, more uniformly, and more precisely in a more controllable and forgiving manner in the assembly of individual cells than is required when multiple cells are compressed simultaneously during the assembly of a larger cell stack. Also, because they are already internally compressed, the individual cells can be assembled into or within a cell stack without the need for specific or high overall compression that must be precisely applied in the face and lateral directions, as is typically required for the assembly of filter press type cell stacks. Furthermore, the individual cells can be individually tested to determine whether the internal compression and operation is correct before forming the cell stack. This option is not available when the required cell assembly and compression (clamping force) occurs only during the formation of the cell stack, as is typically required, especially in filter press type cell stacks. In addition, individual cells that are not functioning properly or that lose the required compression during operation can be easily removed and replaced in the cell stack. This option was also not available previously, and the entire conventional cell stack must be disassembled and then reassembled, which is a laborious and time-consuming task. (2) The polymer-metal bond between the metal bipolar plates 17 and 18 and the uncovered exposed polymer surfaces on both sides of the cell frame 11 results in a complete sealing of the "cell body" of each individual cell. That is, the "cell body" of each cell is sealed internally by its components. That is, the internal regions of the cell are sealed, or in other words, the cell is sealed. This reduces the need for accurate and precise face and lateral compression to produce a reliable seal, as is typically required during assembly of filter press type cell stacks. Also, before assembling the cell stack, each individual cell can be tested individually to determine whether the cell body is properly sealed. This option is not available if the required sealing of the cell body occurs only during the formation of the cell stack. In addition, cells that develop a failure in the cell body seal during operation can be easily removed and replaced in the cell stack. This option is not available in conventional cell stacks, where the entire conventional cell stack must be disassembled and then reassembled, which is a laborious and time-consuming task. (3) The polymer-metal bond between the metal bipolar plates 17 and 18 and the uncovered exposed polymer surfaces on both sides of the cell frame 11 results in the individual cell components being positioned in the optimum location around the cell frame and within the cell. That is, the compressive components 15 and 16 (e.g., the spring porous transport layers 15 and 16) and the electrodes 13 and 14 are held in the correct location within the cell under compressive tension. This reduces the need for precise placement of the cell components during the formation of the cell stack. Also, before the cell stack is formed, each individual cell can be tested individually to determine whether the components are correctly positioned. This option is not available if the required placement of the cell components occurs only during the formation of the cell stack. In addition, cells that are incorrectly positioned due to component movement during operation can be easily removed and replaced in the cell stack. This option is not available in conventional cell stacks, where the entire conventional cell stack must be disassembled and then reassembled, which is a laborious and time-consuming task.

[0139] Figure 2 illustrates a schematic of another example preferred embodiment electric energy or electrosynthesis cell 100. As shown, the components included in rows A and B are the same as in Figure 1. However, in this example embodiment, metal-to-metal bonding, e.g., metal-to-metal welding, is used to attach the second metallic bipolar plate 18 to the second compressive component 16 (e.g., the second metallic porous transport layer compressive component 16) and the second metallic electrode 14, thereby forming a second metal-to-metal bonded assembly 114.

[0140] Similarly, metal-to-metal bonding, e.g., metal-to-metal welding, is used to attach the first metallic bipolar plate 17 to the first compression component 15 (e.g., the first metallic porous transport layer compression component 15) and the first metallic electrode 13, thereby forming a first metal-to-metal bonding assembly 113.

[0141] Column D of FIG. 2 shows a polymer assembly 112 (which includes a polymer cell frame 11 and a polymer inter-electrode separator 12 attached and sealed to each other via a polymer-to-polymer bond) and, disposed on either side thereof, a second intermetallic bond assembly 114 (which includes functional components of one of the half-cells bonded to each other, e.g., metal-to-metal welded) and a first intermetallic bond assembly 113 (which includes components of the other half-cell bonded to each other, e.g., metal-to-metal welded).

[0142] The cell 100 is formed when a first metallic bipolar plate 17 (part of a first metal-to-metal bond assembly 113) and a second metallic bipolar plate 18 (part of a second metal-to-metal bond assembly 114) are securely attached by polymer-metal bonds to uncovered exposed polymer surfaces on both sides, i.e., on the front and back sides of the cell frame 11, respectively, and around the top, bottom, and both sides of the cell frame 11.

[0143] The polymer-metal bonds between the metal bipolar plates 17 and 18 and the polymer cell frame 11 seal the “cell body” of the cell 100 .

[0144] The polymer-metal bond between the metallic bipolar plates 17 and 18 and the polymer cell frame 11 also causes compression components 15 and 16 (e.g., spring porous transport layers 15 and 16), which are part of metal-to-metal bonded assemblies 113 and 114, respectively, to exert an inward clamping force on the electrodes 13 and 14, respectively, thereby compressing the electrodes 13 and 14 tightly against the sides of the interelectrode separator 12. The electrodes 13 and 14 are part of metal-to-metal bonded, e.g., metal-to-metal welded, assemblies 113 and 114, respectively.

[0145] 2 illustrates a case where both compression components 15 and 16 (e.g., porous transport layer compression components 15 and 16) have a compression function. However, it should be understood that an alternative preferred example includes one of compression components 15 and 16 (e.g., one of porous transport layers 15 and 16) having a compression function, e.g., the first compression component 15 (i.e., being a metallic porous transport layer compression component), and the other having a compliant function, e.g., porous transport layer 16 (i.e., being a metallic porous transport layer compliant component).

[0146] The bottom right image of Figure 2 shows the cell 100 assembled in this way. As can be seen from Figure 2, all of the important points (1)-(3) mentioned above in the description of Figure 1 also apply to the cell 100 of Figure 2.

[0147] FIG. 3 shows a schematic of a most preferred embodiment of an electric energy or electrosynthesis cell 1000. As shown, the components included in row A are the same as in FIG. 1 and FIG. 2. However, in this embodiment, components 15 and 16 are not present (e.g., porous transport layer compression components 15 and 16 are not present). Instead, bipolar plates 17 and 18 are the compression components. The bipolar plates can also function as porous transport layers, i.e., they have a porous structure on the surface facing electrodes 13 and 14, respectively, that allows gas or liquid to access electrodes 13 and 14, respectively. The nature and properties of such porous structures are described in the following sections.

[0148] That is, as shown in column E of FIG. 3 , the metal functional component of one half-cell includes a second compressed metal bipolar plate 18 (i.e., second metal bipolar plate compressive component 18) and a second metal electrode 14, and the metal functional component of the other half-cell includes a first compressed metal bipolar plate 17 (i.e., first metal bipolar plate compressive component 17) and a first metal electrode 13.

[0149] In the example shown in Figure 3, an electric energy or electrosynthesis cell 1000 is shown including a polymeric cell frame 11, a first electrode 13, and a second electrode 14. An inter-electrode separator 12 is sealed to the cell frame 11 and disposed between the first electrode 13 and the second electrode 14. A metallic bipolar plate compression component 17 is disposed adjacent to, next to, or abutting the first electrode 13.

[0150] Preferably, the polymer cell frame 11 is sealed to the metal bipolar plate compression component 17. In one example, the seal between the polymer cell frame 11 and the metal bipolar plate compression component 17 is formed by a polymer-metal bond. In another example (detailed in the Cell Architecture section of the second preferred embodiment example below), at least one polymeric structural positioning component (not shown in FIG. 3) positions the metal bipolar plate compression component 17 relative to the polymer cell frame 11. In this example, the seal between the polymer cell frame 11 and the metal bipolar plate compression component 17 may be formed by one or more polymer-to-polymer bonds between the at least one polymeric structural positioning component and the polymer cell frame 11, and at least one polymeric structural positioning component that mechanically holds the metal bipolar plate compression component 17 relative to the polymer cell frame 11.

[0151] The second metal bipolar plate compression component 18 is disposed adjacent to, next to, or abutting the second electrode 14. Preferably, the polymer cell frame 11 is sealed to the second metal bipolar plate compression component 18. In one example, the seal between the polymer cell frame 11 and the second metal bipolar plate compression component 18 is formed by a polymer-metal bond. In another example (detailed in the cell architecture section of the second preferred embodiment example below), at least one additional polymer structure positioning component (not shown in FIG. 3) positions the second metal bipolar plate compression component 18 relative to the polymer cell frame 11. In this example, the seal between the polymer cell frame 11 and the second metal bipolar plate compression component 18 may be formed by one or more additional polymer-to-polymer bonds between the at least one polymer structure positioning component and the polymer cell frame 11, and at least one polymer structure positioning component that mechanically holds the second metal bipolar plate compression component 18 relative to the polymer cell frame 11.

[0152] The first electrode 13 and the second electrode 14 are disposed within a polymeric cell frame 11. For example, as shown, the polymeric cell frame 11 includes a window cutout, and the first electrode 13 and the second electrode 14 are disposed within the window cutout of the polymeric cell frame 11. An inter-electrode separator 12 is also disposed in the polymeric cell frame 11 between the first electrode 13 and the second electrode 14. Preferably, the inter-electrode separator 12 is a polymeric inter-electrode separator, and the polymeric cell frame 11 is bonded to the polymeric inter-electrode separator via a polymer inter-electrode bond. Preferably, the first electrode 13 is a first metal electrode, and the second electrode 14 is a second metal electrode.

[0153] Also, metal-to-metal bonding, e.g., metal-to-metal welding, may be used to attach the second metallic bipolar plate compression component 18 to the second metallic electrode 14 to form a second metal-to-metal bond assembly 118. Similarly, metal-to-metal bonding, e.g., metal-to-metal welding, may be used to attach the first metallic bipolar plate compression component 17 to the first metallic electrode 13 to form a first metal-to-metal bond assembly 117.

[0154] FIG. 4(a) shows an example embodiment of a metal bipolar plate compression component 17 or 18 (i.e., a metal waffle bipolar plate) that may be suitable for direct attachment to such metal electrodes and for attachment of a metal electrode 13 or 14 to the metal bipolar plate compression component via a metal-to-metal bond, such as a metal-to-metal weld.

[0155] The metallic bipolar plate compression component 17 or 18 has a flow field with a "waffle" structure 181 (or a grid-like or lattice-like arrangement of pits and lands, or ribs and spaces, or steps and voids) on a portion of its surface. The "waffle" structure resembles to some extent the structure present in a waffle iron. The metallic bipolar plate compression component 17 or 18 shown in FIG. 4(a) is a metal sheet whose surface has been etched, machined, stamped, molded, sunk, or otherwise shaped into the waffle structure 181, i.e., a grid structure or lattice. The metallic bipolar plate compression component 17 or 18 also has a flat peripheral area 182 around the waffle structure 181 where no flow field is inscribed. The waffle portion of the metallic bipolar plate 17 or 18 may have a somewhat dome-shaped shape, which attests to the fact that it has spring or spring properties.

[0156] In step A of FIG. 4(a), a metal electrode 13 or 14, which is a metal mesh electrode, is placed on the waffle structure 181. The metal mesh electrode is then attached directly to at least some or all of the lands of the waffle structure 181 in step B by metal-to-metal bonds, e.g., metal-to-metal welding, that attach the metal electrode 13 or 14, i.e., the metal mesh electrode, to some or all of the ribs or steps of a grid structure or lattice on the face of the metallic bipolar plate compression component 17 or 18. The resulting metal-to-metal bonded assembly 117 or 118 includes the metal electrode 13 or 14, respectively, attached by metal-to-metal bonds to some or all of the lands of the waffle structure 181, leaving the flat peripheral region 182 of the metallic bipolar plate compression component around the waffle structure 181 intact.

[0157] 4(b) is a close-up view of how such intermetallic bonds can be achieved. A metal electrode 13 or 14 (in this case a metal mesh electrode) is placed on top of the waffle structure 181. Then, at some or all of the points 183 where the strands of the mesh 13 or 14 overlap the lands of the waffle structure 181, intermetallic bonds, e.g., intermetallic welds, can be formed.

[0158] This type of metal-to-metal bond, e.g., metal-to-metal welding, can stabilize the structure of the bipolar plate and stop, slow, or avoid distortions such as "springback." In doing so, the metal-to-metal bond can minimize variations in the physical dimensions of the bipolar plate and its flow fields, thereby enabling the use of precision industrial stamping, molding, and other high speed, high volume manufacturing processes.

[0159] Metal-to-metal bonds between the metal bipolar plate compression component (i.e., metal waffle bipolar plate 181) and the metal electrodes 13 or 14 may further provide high electrical conductivity between these components and uniform distribution of current and voltage at the attached electrodes. The number of metal-to-metal bonds may be selected to be the optimum number taking into account the desired electrical conductivity between these components and the desired area distribution of current and voltage at the attached electrodes.

[0160] Also, the metal-to-metal bond between the metal bipolar plate compression component (i.e., metal waffle bipolar plate 181) and the metal electrodes 13 or 14 may provide high thermal conductivity between these components and uniform distribution of heat generated by the cell. For example, heat generated at the electrodes may be efficiently conducted to the metal bipolar plate compression component 17 or 18, which may be cooled, thereby maintaining the temperature of the cell.

[0161] Returning to FIG. 3, column F of FIG. 3 shows a polymer assembly 112 (which includes a polymer cell frame 11 and a polymer interelectrode separator 12 attached and sealed to each other via a polymer-to-polymer bond) on either side of which are disposed a metal assembly 118 (which includes a metal-to-metal bonded metallic bipolar plate compression component 18 and a second electrode 14, i.e., a metallic functional component of one of the half cells) and a metal assembly 117 (which includes a metal-to-metal bonded metallic bipolar plate compression component 17 and a first electrode 13, i.e., a metallic functional component of the other half cell).

[0162] Cell 1000 is formed when metal bipolar plate compression component 17 (part of metal-to-metal bond assembly 117) and metal bipolar plate compression component 18 (part of metal-to-metal bond assembly 118) are attached by polymer-metal bonds to exposed uncovered polymer surfaces at the front and back sides of polymer cell frame 11, respectively, and around the top, bottom, and both sides of polymer cell frame 11.

[0163] This may involve the peripheral area of ​​the metal waffle bipolar plate 17 or 18 (e.g., the flat peripheral region 182 in FIG. 4) being attached to the polymer cell frame 11 via one or more polymer-metal bonds. The bottom right image of FIG. 3 shows the cell 1000 assembled in this manner. The slightly dome-shaped shape of the waffle structure 181 may thereby be flattened, meaning that its springy nature has been utilized to exert an internal clamping force on the attached electrode 13 or 14 in the cell 1000, thereby compressing the electrode 13 or 14 against the interelectrode separator 12. That is, when assembled by forming a polymer-metal bond between 117 or 118 and the cell frame 11, the spring waffle structure in 117 or 118 provides a compression component that firmly clamps the attached electrode 13 or 14, respectively, against the interelectrode separator 12.

[0164] The polymer-metal bond between the metallic bipolar plate compression components 17 and 18 and the polymer cell frame 11 may further seal the "cell body" of the electrosynthetic or electrical energy cell 1000. The example of FIG. 3 shows the case where both metallic bipolar plate compression components 17 and 18 have a compressive function. However, it should be understood that an alternative preferred example includes one of the metallic bipolar plate compression components 17 or 18 having a compressive function and the other having a compliant function. For example, a metallic bipolar plate compression component and a metallic bipolar plate compliant component may be provided.

[0165] It should be understood that the purpose of such a waffle bipolar plate in this example embodiment is to include and integrate the functionality of a porous transport layer within the bipolar plate. Thus, the waffle structure includes voids between the lands of the waffle, which provide the same type of porosity found in a porous transport layer. Thus, any bipolar plate flow field that provides such voided porosity can potentially be used without the need for a separate porous transport component. That is, the illustrated waffle structure provides just one example of a bipolar plate that can also function as a porous transport layer. Any porous bipolar plate with such voids can fall within the scope of the term "waffle bipolar plate" or "metal waffle bipolar plate."

[0166] It should be further understood that while only Figures 3, 4, and associated text explicitly state the use of metal waffle bipolar plates, the example embodiments described using Figures 1, 2, and their associated text may also utilize one or more metal waffle-type bipolar plates.

[0167] As can be seen from Figure 3, all of the key points (1)-(3) discussed above in the text relating to Figure 1 also apply to cell 1000 of Figure 3. A distinctive feature of exemplary cells 10, 100, and 1000 is the complete lack of a gasket in their cell architecture.

[0168] In addition, intermetallic bonds, such as metal-to-metal welds, can provide reduced or unchanged electrical resistance between metal functional materials, thereby providing improved energy efficiency from the electric energy or electrosynthesis cell during operation. Preferred embodiments can employ such intermetallic bond structures because the compression involved in cell assembly is too low to damage or destroy the intermetallic bonds, such as intermetallic welds, and again low compression may be required when the assembled cells are subsequently integrated into a cell stack. In contrast, as discussed in the background section, conventional cell stack formations typically require much higher compression, and such high compression can easily damage or destroy existing intermetallic bonds (e.g., intermetallic welds).

[0169] Preferably, the polymeric inter-electrode separator in the above example embodiments is thin, thereby maximizing the energy efficiency of the cell. Preferably, the polymeric inter-electrode separator has a thickness of less than 0.35 mm, less than 0.2 mm, less than 0.1 mm, less than 0.05 mm, or less than 0.025 mm.

[0170] Preferred embodiment cell stack assembly 5 illustrates diagrammatically how exemplary cells 10, 100, or 1000 may be stacked in a cell stack 20. The apertures / openings at the top of each cell 10, 100, 1000 (e.g., 21-23 in FIG. 5) and the apertures / openings at the bottom of each cell 10, 100, 1000 (e.g., 24-25) are known as header or manifold apertures. The header / manifold apertures / openings of each cell in the stack line up after assembly of the stack, thereby effectively forming a pipe that runs the length of the cell stack 20.

[0171] Typically, in conventional filter press type cell stacks, the headers, as formed by the apertures / openings 21, 22, 23, 24, 25, are sealed together by tightly compressing the cells in the stack between the two end plates during assembly of the stack and maintaining such compression thereafter. A certain high compression is generally required to ensure that liquids and / or gases in the headers cannot escape the formed pipes or mix by flowing into the spaces between the cells. The metal bipolar plates between the cells in such filter press type cell stacks are similarly sealed to the cell frame by compression, as described above, and not by polymer-metal bonding. The necessary compression of the components of each cell, including the clamping of the electrodes to the interelectrode separators, is also typically provided by compression applied to the cell stack during and after its formation.

[0172] However, in preferred embodiment examples, the bipolar plates are already attached to the cell frame by polymer-metal bonding during assembly of the cells, so there is no need to seal the bipolar plates by compressing the cell stack. Also, the necessary clamping force compressing the electrodes against the inter-electrode separators of each cell may not need to be provided since such clamping force is already present as a result of (pre-)assembling the cells. This may reduce the need for accurate and precise face-wise and lateral compression of the cell stack during and after its formation.

[0173] Thus, the cell stack of the preferred embodiments is preferably formed (and completely sealed) by moderately compressing the cells together and then sealing the header / manifold aperture or opening of each cell against the equivalent header / manifold aperture or opening of the next cell in the stack until all of the header / manifold apertures or openings in the stack are sealed. Also, all of the header / manifold apertures or openings in the stack may be sealed at the same time, i.e., they may be sealed all at once.

[0174] A header / manifold aperture or opening of an electrosynthesis or electrical energy cell may be sealed to an equivalent header / manifold aperture or opening of the next cell in the stack during assembly of the cell stack via one or more interpolymer bonds. That is, an assembled cell whose "cell body" is already sealed by its cell architecture may be completely sealed during assembly of the cell stack by forming liquid and / or gas connections to and from the remainder of the cell stack via interpolymer bonds. Such interpolymer bonds may further reduce the need for precise and accurate compression to form seals during and after assembly of the cell stack.

[0175] Any polymer-polymer bonding technique may be used to form the required bonds, including any of the polymer-polymer bonding techniques described or enumerated herein.

[0176] In a particularly preferred example, such interpolymer bonds may be formed on each cell by patterning and placing resistive metal wire or electrical circuitry around the polymer header / manifold aperture to be sealed. After the cells are stacked and compressed to the required degree for cell assembly, electrical current may be passed through each circuit present, causing heating of each circuit and resulting in melting and fusing of the polymeric material of adjacent cells around the circuit. The resulting cell stack architecture may include cells stacked and bonded via interpolymer bonds incorporating resistive wire and / or electrical circuitry around the header / manifold aperture.

[0177] In another preferred example, a gasket, such as a molded sheet or ring of rubber, may be placed around a first portion of the polymeric area to be sealed, followed by the type of interpolymer sealing described above in a second portion of the polymeric area to be sealed. The gasket may provide an additional long-term defense against leakage, which may be particularly useful when structurally complex interpolymer bonds are required. The resulting cell stack architecture may include cells stacked and bonded around the header / manifold apertures, with gaskets near the interpolymer bonds, via interpolymer bonds incorporating resistive wires and / or electrical circuits.

[0178] In other instances, the required inter-polymer welds may be too complex or demanding to reliably seal, in which case one or more gaskets may be used. The resulting cell stack architecture may include stacked cells with one or more gaskets around the header / manifold apertures, where compression of the stack maintains the gasket seal.

[0179] The above sealing architectures can provide simplified and reliable assembly of components and cells into or within cell stacks without leakage or mixing of liquid or gaseous reactants and products, both after assembly and during subsequent operation, and they can provide for high speed, high volume industrial assembly of electrosynthesis or electrical energy cell stacks.

[0180] In one example, the cell stack is a filter press type cell stack. In another example, the liquid inlet headers of the cells in the cell stack are pressurized to a pressure higher than the liquid in each cell, and the liquid outlet headers of the cells in the cell stack are pressurized to a pressure lower than the liquid in each cell. In a preferred example, the overall compressive pressure applied to the cell stack during assembly and thereafter (such as during electrochemical operation) is greater than 0.01 bar, greater than 0.02 bar, greater than 0.03 bar, greater than 0.04 bar, greater than 0.05 bar, greater than 0.075 bar, greater than 0.1 bar, greater than 0.2 bar, greater than 0.3 bar, greater than 0.5 bar, greater than 0.75 bar, greater than 1 bar, greater than 2 bar, greater than 3 bar, greater than 4 bar, greater than 5 bar, greater than 10 bar, greater than 15 bar, greater than 20 bar, greater than 30 bar, greater than 40 bar, greater than 50 bar, or greater than 100 bar.

[0181] Compression may be maintained by torsional, mechanical, hydraulic (i.e., liquid), or other means capable of accommodating dimensional changes in the length of the cell stack, such as may occur during repeated temperature or pressure cycling.

[0182] FIG. 6 shows a schematic of sealing of the header / manifold apertures on each cell by patterning and placing resistive metal wire or electrical circuitry around the polymer header / manifold aperture to be sealed.

[0183] FIG. 6 shows a cell 301 having multiple header apertures 303-308. A second cell 302 having comparable header apertures is placed facing the cell 301 with its header apertures matching the header apertures 303-308 of the cell 301. To seal the header apertures 303-308 of the cell 301 to the comparable header apertures of the cell 302, a wire 309 (preferably a thin wire) may be bent into a pattern matching the headers, and then the wire 309 is placed around the headers 303-308 on the surface 310 of the cell 301. The cell frames 301 and 302 are then compressed together, and a current is passed along the wire 309 by connecting a suitable power source across both ends 3091 and 3092 of the wire 309. The wire 309 heats up as a result of the current passing through it, melting the polymer in adjacent cells 301 and 302 and fusing the polymer cell frames of cells 301 and 302 around the wire 309, thereby sealing the headers 303-308 of cell 301 to the corresponding headers of cell 302. This process can be repeated with multiple cell frames to form a sealed cell frame stack. In one example, the liquid inlet headers of the cells in the cell stack can be pressurized to a higher pressure than the liquid in each cell, and the liquid outlet headers of the cells in the cell stack can be pressurized to a lower pressure than the liquid in each cell.

[0184] In this manner, it may be possible to assemble electrical energy cell stacks or electrosynthetic cell stacks with moderate to little compression during assembly and subsequent operation, and the need to maintain the cell stack under precise lateral and facial compression over its operational life after assembly of the stack may be reduced or entirely eliminated.

[0185] Also, placing this type of patterned wire around the periphery of the cell frame may allow multiple cell frames to be welded together in the same manner. Patterned wire may be further placed around other headers and / or other features to seal them in the same manner.

[0186] It should be understood that there are numerous alternatives for wire 309. For example, instead of a wire, a thin polymer film coated with a layer of conductive metal and cut to the shape shown for 309 may be used. Such a polymer cutout may be arranged as shown for 309 in FIG. 6. By including a cutout polymer film (coated with a thin layer of conductive metal and shaped as shown for 309) between the polymer cell frames of cells 301 and 302 when cells 301 and 302 are compressed together, a better seal than a wire may be formed (when electrically heated to form a seal).

[0187] The above types of "cell-to-cell" polymer-to-polymer bonds can further reduce the challenge of forming a seal with accurate and precise compression during formation of the cell stack. They can also provide a more reliable seal that is less dependent on maintaining a consistent high compression across the cell stack. In contrast, conventional cell stacks rely essentially entirely on a consistent high compression to form and maintain such a "cell-to-cell" seal.

[0188] Preferred embodiment example: Cell architecture of the second preferred embodiment example: Use of "Structural Positioning Components" In other example embodiments, the dimensions of the polymeric components (e.g., cell frame 11 and interelectrode separator 12) may change more than the dimensions of the metallic components (e.g., bipolar plates 17 and 18, porous transport layers 15 and 16, and electrodes 13 and 14) during thermal or pressure cycling of the type that may occur during operation. This may be due to differences in the thermal or pressure-induced expansion coefficients of the polymeric components relative to the metallic components.

[0189] In such cases, it may not be possible to achieve a reliable seal by physically attaching a metal component (e.g., bipolar plate 17 or 18) to a polymeric component (e.g., cell frame 11) via one or more polymer-metal joints. Instead, it may be necessary to structurally restrain one or more physically separated metal components close to or in intimate contact with the polymeric component, thereby sealing their joint. Alternatively, a suitably shaped gasket may be placed between the metal and polymeric components, thereby sealing their joint more tightly. Creating a close structural match between the metal and polymeric components may ensure that operational stresses on the gasket may be minimized during operation of the cell.

[0190] In a second non-limiting preferred embodiment, an electrical energy or electrosynthesis cell architecture includes at least one polymeric cell frame, the at least one polymeric cell frame having: at least one polymeric interelectrode separator by or through one or more interpolymer bonds, at least one polymeric "structural positioning element" that mechanically holds at least one metallic functional element in place within or around the cell frame by or through one or more interpolymer bonds, An electrical energy or electrosynthesis cell architecture is provided, in which the

[0191] Preferably, the polymeric inter-electrode separator in the above example embodiments is thin, thereby maximizing the energy efficiency of the cell. Preferably, the polymeric inter-electrode separator has a thickness of less than 0.35 mm, less than 0.2 mm, less than 0.1 mm, less than 0.05 mm, or less than 0.025 mm.

[0192] The at least one metallic functional component may include a metallic bipolar plate, for example a metallic bipolar plate compression component. The metallic bipolar plate may form part of a metal-to-metal bond assembly including at least one metallic bipolar plate and at least one metallic electrode, and optionally at least one metallic porous transport layer. The at least one polymeric structural positioning component may mechanically hold the metal-to-metal bond assembly in a suitable position inside or around the cell frame. The metal bipolar plate of the at least one metal-to-metal bond assembly may be held in intimate contact with the polymeric cell frame, thereby sealing their joints. Alternatively, a suitable gasket may be present between the bipolar plate and the cell frame, thereby providing improved sealing.

[0193] Alternatively, the at least one metallic functional component may comprise a metallic electrode or a metallic porous transport layer. The metallic electrode or metallic porous transport layer may form part of a metal-metal bond assembly comprising at least one metallic bipolar plate at a suitable location within or around the cell frame. The at least one polymeric structural positioning component may mechanically hold the at least one metal-metal bond assembly at a suitable location within or around the cell frame.

[0194] FIG. 7 shows a schematic of an example of a single half-cell of the preferred embodiment.

[0195] The top left of Figure 7 shows a metal waffle bipolar plate 41 (i.e., a metal bipolar plate compression component) that includes a waffle structure area 412 and a surrounding peripheral area 413 that is flat and has no flow field thereon. Structure 411 is a schematic representation of a cross section of the waffle bipolar plate 41, showing the pits (e.g., pit 4111) and lands (e.g., land 4112). The waffle bipolar plate may be fabricated, for example, by an industrial precision stamping or molding process.

[0196] In step A of Fig. 7, a metal electrode 42, preferably a flat metal mesh electrode, is attached to at least some or all of the lands of 411 by one or more metal-to-metal bonds, e.g., metal-to-metal welds. This may include, for example, welding the metal electrode 42 to the bipolar plate 411 at some or all of the lands (e.g., 4112). The resulting electrode-bipolar plate assembly 43 (shown in cross section) is a single metal part held together by metal-to-metal bonds, e.g., metal-to-metal welds. The peripheral area 413 of the bipolar plate 41 (the flat peripheral region that does not have a flow field thereon) is separate from the waffle portion to which the metal electrode 42 is attached, and is shown as section 4121 of the electrode-bipolar plate assembly 43.

[0197] The top right of Figure 7 shows a schematic of a polymeric "structural positioning component" 44, which has the form of a polymeric cover disk having a flattened donut shape shown in cross section diagrammatically as cross section 441. The central opening of the polymeric "structural positioning component" 44 is sized to partially enclose the bipolar plate 41 and attached metal electrode 42 (i.e., electrode-bipolar plate assembly 43). Cross section 45 after step B of Figure 4 shows in schematic cross section how the electrode-bipolar plate assembly 43 fits into and is covered by the polymeric "structural positioning component" cross section 441.

[0198] The bottom left of Figure 7 shows a cell frame 11 incorporating an attached inter-electrode separator 12, fabricated as described for assembly 112 in Figures 1, 2, and 3. The resulting assembly 112 is shown in schematic cross-section as cross section 461.

[0199] 7, Step C shows a cross section of a polymer "structural positioning component" cross section 441 with its (i.e., assembly 45) internal electrode-bipolar plate assembly 43 attached to the cell frame 11 (i.e., within assembly 112) by polymer-polymer bonds. The resulting polymer-polymer bonds of assembly 471 are shown at location 4511.

[0200] As can be seen from the schematic cross-sectional view of the assembly 471, the peripheral area 413 (i.e., the flat peripheral area having no flow field thereon) of the metallic bipolar plate 41 (i.e., section 4121) may thereby be mechanically held close to or in intimate contact with the inner surface 4112 of the polymeric "structural positioning component" 44. In doing so, the joint between the metallic bipolar plate 4121 and section 4112 of the polymeric "structural positioning component" 44 may be sealed. Nevertheless, the electrode-bipolar plate assembly 43 may be physically decoupled from the polymeric structure of the assembly 471. The somewhat bowed shape of the compressed waffle bipolar plate 41 may now be flattened, indicating that its spring (or spring) properties have been utilized in the assembly 471 to exert a clamping force compressing the attached electrode 42 against the interelectrode separator 12.

[0201] The polymer-polymer bond at location 4511 in assembly 471 may be formed by polymer components with very similar coefficients of expansion. Thus, the polymer-polymer bond at location 4511 in assembly 471 is unlikely to pull apart during thermal or pressure cycling. Also, metal components 43, which may have very different coefficients of expansion, are not physically connected to the polymer components. Thus, there are no polymer-metal bonds that may pull apart during thermal or pressure cycling due to mismatches between the polymer and metal coefficients of expansion. Thus, this arrangement can accommodate mismatches between the coefficients of expansion of the polymer and metal components during thermal and pressure cycling. That is, the expansion of the metal assembly 431 does not need to match the expansion of the polymer structure because the metal components are physically separated from the polymer components.

[0202] As shown in the assembly 481 after the arrow D in FIG. 7, a gasket 4711 conforming to the periphery of the bipolar plate 41 may additionally be introduced at the junction of the metal bipolar plate 41 (i.e., section 4121) and the polymeric "structural positioning element" 44 (i.e., section 4112). That is, the gasket 4711 is placed at the junction between the metal bipolar plate and the polymeric cell frame. Such a gasket 4711 may provide improved sealing. The close structural conformity of the metal bipolar plate (i.e., section 4121) and the polymeric "structural positioning element" 44 (i.e., section 4112) may minimize the operating stresses on the gasket during operation of the cell.

[0203] Alternatively, as shown in assembly 491 after arrow E in Figure 7, a gasket 4712 may be inserted at the joint between the metal bipolar plate 41 (i.e., section 4121) and the polymeric cell frame 11. Such a gasket 4712 may also provide improved sealing. Also, the close structural match between the metal bipolar plate (i.e., section 4121) and the polymeric cell frame 11 may minimize operational stresses on the gasket during operation of the cell.

[0204] In this preferred embodiment, the location selected for the gasket may depend on a variety of factors, including structural changes of adjacent polymeric and metallic components during thermal or pressure cycling. A feature of the cell of such example embodiment is the use of at least one gasket 4711 in at least one of its half-cells during its assembly and operation.

[0205] By these means it is possible to produce sealed cells that can be tested for quality control purposes before assembly into a cell stack 20 as shown in FIG. 5. In such a cell stack 20, the bipolar plates 41 of adjacent cells need to be in electrical contact with each other. The cross-sectional assembly 491 of FIG. 7 shows that such contact can be easily made with the cell of the example embodiment. As shown, the pits 4111 of the bipolar plates 41 of adjacent cells can be in direct contact with each other even during mild compression of the cell stack. Such compression can further provide improved sealing at the joints between the metal bipolar plates 41 (i.e., section 4121) and the polymeric "structural positioning elements" 44 (i.e., section 4112) and / or the polymeric cell frame 11.

[0206] The contacting polymer "structural positioning elements" 44 (i.e., sections 4112) of adjacent cells can potentially be attached to one another by polymer-to-polymer bonds, for example, along the entire periphery of the "structural positioning elements" or at selected locations around the periphery. Such polymer-to-polymer welds in effect lock in any compression applied to the cell stack, permanently maintaining all cells in the stack in a compressed, sealed state. That is, this type of polymer-to-polymer bond can avoid the need to externally maintain the cell stack in a compressed state at all times after the cell stack is assembled (including during electrochemical operation). This type of polymer-to-polymer bond can also be reliably and securely fixed and not subject to pulling apart due to mismatched thermal expansion coefficients.

[0207] Another alternative is to join some or all of the pits (i.e., pits 4111) of the waffle bipolar plates of adjacent cells in the assembly 491 together by metal-to-metal joints, such as may be formed by laser welding. Such metal-to-metal joints can also be reliably and securely fixed and not subject to pulling apart due to mismatched thermal expansion coefficients. Such joints also ensure good electrical contact between the cells and throughout the cell stack. However, the lateral compression applied to the cell stack needs to be maintained permanently and during operation (unless the circumferential sections 4112 of the polymer cover disk cross-sections 441 on adjacent cells are also fixed together).

[0208] Optionally, the waffle structure on the bipolar plate 411 in one cell may be structurally complementary to the waffle structure on the bipolar plate 411 of an adjacent cell, allowing the two waffle structures to interlock and fit together when two such waffle structures are compressed together during stack assembly. Such structural interlocking may help ensure optimal alignment of the cells in the cell stack. It may also provide an increased surface area for electrical contact between the cells in the cell stack.

[0209] To the extent that the seal formed by the polymer-metal bond described in FIG. 1 and the associated text is equivalent to the polymer-metal seal of the cell of the preferred embodiment example described above, all of the key points (1)-(3) described in the associated text of FIG. 1 also apply to the cell of the preferred embodiment example described above.

[0210] Tolerance Compensation Features In various other examples, the embodiments relate to polymer-polymer, polymer-metal, and metal-metal joints that may be used in the cell and cell stack architectures and techniques described above. Preferably, such joints incorporate one or more "tolerance compensating features." By "tolerance compensating features" we mean features that accommodate the low tolerances and high variability in the dimensions of the cell components, such as in a polymer cell frame that may be injection molded. Tolerance compensating features include structures designed to accommodate the variability of the components being joined. These include channels, grooves, slots, tongues, and other structural features that are slightly oversized, slightly undersized, or slightly mismatched relative to another feature to accommodate variations in the amount of material released during joining. Some tolerance compensating features may be incorporated into push-fit mating components, such as tongues and grooves, locating pins, and holes.

[0211] Preferably, but not exclusively, the following joints described below, which incorporate tolerance compensation features, may be used. (1) "Sealed Wire Welding" Joint (2) "Ridge polymer-metal" bonding

[0212] Figure 6 shows a schematic of sealing of the header / manifold apertures during cell stack assembly by patterning and placing resistive metal wire or electrical circuitry around the polymeric header / manifold aperture to be sealed on each cell. Figure 8 shows a schematic of a tolerance compensation feature that may be incorporated into such a sealing process. The tolerance compensation feature forms part of a push-fit mating component, i.e., a tongue and groove or fit. The tolerance compensation feature is referred to as a "seal wire weld."

[0213] As can be seen from the schematic cross-sectional view shown in Figure 8(a), resistive wire 500 is contained within a groove 550 on one side 520 of the polymer-polymer bond. Groove 550 is slightly oversized relative to the tongue protruding from the other side 510 of the polymer-polymer bond. This leaves a larger volume than would normally be needed to accommodate the tongue from the other side 510, as shown by the dashed lines in Figure 5(a). That is, gap 540 between the bottom of the tongue from the other side 510 and the bottom of the groove on side 520 is larger than gap 530 between one side 520 and the other side 510 of the polymer-polymer bond.

[0214] As shown in Figure 8(b), when the cell stack is assembled, the interpolymer joints between the different cells are aligned as shown in stack 5000. The wire at the left-most joint is then heated by passing an electric current through it, causing its tongue to melt and partially fill the groove, thereby leaving a reduced but non-zero free volume 560. Typically, tongue-and-groove joints leave zero free volume when engaged.

[0215] Thus, slightly oversized grooves can compensate for variations in the physical dimensions of the parts, provided that the grooves are sized such that there is always some free volume 560 remaining after melting. That is, variations in the physical dimensions of the parts (i.e., lower tolerances) can be compensated for by changes in free volume 560 as the inter-polymer bond progresses from left to right in the stack.

[0216] Another tolerance compensation feature is shown in cross section in FIG. 9. A polymeric component 570 (e.g., a polymeric cell frame) is attached to a metal component 571 (e.g., a bipolar plate) via the lands of two raised ridges 572 and 573. The ridges have voids 574 between and around them. Upon thermal heating of the assembly, the polymeric component 570 may expand more than the metal component 571. In that case, the ridges 572 and 573 are able to deform and bend to accommodate the expansion mismatch without destroying their attachment to the metal component 571. They are able to do so because of the voids 574 between and around the ridges 572 and 573. To provide redundancy, two such ridges may be used, although a single ridge or any number of ridges may be used, including three or more ridges. Such a bond is referred to herein as a "ridge polymer-metal" bond.

[0217] It should be understood that the above list of bonds incorporating "tolerance compensating features" is not exhaustive. All forms of polymer-polymer bonds, polymer-metal bonds, and metal-metal bonds that include "tolerance compensating features" may be used in preferred embodiments.

[0218] Polymer-Metal and Polymer-Polymer Bonds of the Preferred Embodiments In various other example aspects, embodiments relate to polymer-polymer and polymer-metal bonds that may be used in the cell and cell stack architectures and techniques described above to seal cells and / or one component to another, for example, to seal a polymer cell frame to a metal bipolar plate compression component.

[0219] Many such polymer-metal bonds are formed by fluidizing and flowing the polymer component, for example by melting the polymer component in selected areas / volumes and then flowing it into or around the metal component. One preferred polymer-metal bond is a mechanically engaged bond. FIG. 10 shows a schematic cross-section of an example of the formation of such a bond. In this technique, the edge of a metal part is expanded and then embedded into the polymer surface using heat. A metal bipolar plate 582, shown in cross-section, has a folded edge 583 as shown. The edge 583 is attached to a polymer cell frame 580 via a polymer-metal bond. A notch 581 is formed in the surface of the cell frame 580. The folded edge 583 of the metal bipolar plate 582 is then heated and pressed into the notch 581 as shown by the small arrow in the leftmost schematic of FIG. 10. The hot folded edge 583 melts the polymer around the notch and the applied force embeds the folded edge 583 into the body of polymer 580. Eventually, the folded edge 583 is fully embedded within the polymer 580, as shown in the schematic on the right side of FIG. 10. The heated press tool includes features that shape the polymer melt into the bond interface and into the cavities formed in the bipolar plate edge beads to improve the mechanical integrity and sealing performance of the bond. This technique is called "continuous edge heat staking" and the bond is called a "continuous edge heat staking" bond.

[0220] Following from the above, another preferred polymer-metal bond involves a seemingly uniform metal surface, such as a seemingly flat metal surface, bonded to a polymer. For such bonds, a generally preferred approach to ensure a robust polymer-metal bond involves preparing the metal surface prior to attaching it to the polymer surface. Preferred pretreatments in this regard include, but are not limited to, the following: (1) Liquid cleaning and / or pickling of metal surfaces to remove contaminants such as corrosion residues, oils, and organic matter; and / or (2) Texturing a metal surface, for example by forming microstructures on the surface, such as pits, holes, grooves, porous protrusions, etc. Preferably, this type of structure has "undercuts" or "inlays" or similar internal voids in which the innermost portion of the structure within the metal body is wider or broader or larger than the "mouth" portion of the structure that opens onto the outermost, external metal surface. When a polymer-metal bond is formed on such a surface, for example by melting a polymer, the polymer can flow into such voids and solidify there. The polymer structures within the structure are then larger than the mouth or mouths of the structure, so that the polymer is mechanically held by the metal surface, thereby promoting firm adhesion. Such texturing of a metal surface can preferably occur by applying to the surface one or more of the following, but is not limited to only: i. laser radiation, ii. Liquid primer; iii. Thermal spraying, metal spraying ("cold spray"), or similar techniques; iv. Plasma spraying, plasma treatment, or similar techniques; or v. Certain corona arc techniques. Such bonds are loosely referred to as "textured metal-polymer" bonds. It should be understood that a variety of techniques exist for forming such bonds, and that the above list is not exhaustive. Any and all such techniques may be used.

[0221] FIG. 11 shows a schematic cross-section of a preferred example of this type of polymer-metal bonding. A metal part 600 and a polymer part 610 are attached by polymer-metal bonding. In the first step of the process, the surface (i.e., the underside) of the metal part 600 to be attached is prepared. This may include texturing the surface as described above, for example by laser texturing. Alternatively or additionally, it may include applying one of the other techniques listed above, or another process not listed above, thereby improving the adhesive capacity for the applied polymer. Many other types of treatments may be used. A thin polymer layer 620 of the same polymer present in the polymer part 610 is then deposited on the treated surface under carefully controlled conditions that provide a strong and robust bonding of the thin polymer layer 620 to the treated metal surface of the metal part 600. Next, the polymer component 610 is compressed against a thin polymer layer 620 that is firmly attached to the metal component 600, and the surface of the metal component 600 is subjected to laser irradiation 640, which heats the metal component 600, as shown in region 645 of Figure 11. This heating causes the polymers at interface 630 to melt and fuse together, thereby forming the desired polymer-metal bond.

[0222] Finally, polymer-metal bonds may also be used where the polymer and metal parts mechanically interlock on a macro-scale. Such bonds may be formed, for example, by cutting a notch into the polymer surfaces to be joined and then bending the end of the metal part to fit into and be held by the notch. Stiffness or tension within the metal part may be utilized with the optional involvement of a spring / spring component. Examples in this regard include, but are not limited to, purely mechanical polymer-metal "roll-formed" bonds.

[0223] FIG. 12(a) shows an “internal roll-formed” bond in cross section. A polymeric component 700 has a notch 730 on its inner surface. The polymeric component 700 may be, for example, a polymer cell frame. Optionally, a gasket 720 may be placed near the notch on the surface of the polymeric component 700. A metal component 710 is then placed in intimate contact with the surface of the gasket 720 and / or the polymeric component 700. The metal component 710 may be, for example, a bipolar plate. Optionally, the gasket 720 may have spring or spring properties (for example, it may be an elastomeric gasket). The metal component 710 is compressed onto the surface of the gasket 720 and / or the polymeric component 700, so that its edge sits above the notch 730. This may be done using a “clamp plate” 740 (as shown in the top right of FIG. 4(b)). Next, a "roll-forming" tool 750 (as shown in the top right of FIG. 4(b)) is used to bend the end of the metal part 710 into the notch, as shown in area 731. In doing so, the metal part can be sealed and fixed to the polymeric part 700 (e.g., a metal bipolar plate can be sealed and fixed to a polymeric cell frame). In this case, the integrity of the polymer-metal seal is maintained by the rigidity of the metal part 710 between the two internal roll-formed joints at 730.

[0224] FIG. 12(b) shows an “external roll-formed” bond in cross section. The polymeric component 700 has a notch 730 on its outer surface. The polymeric component 700 may be, for example, a polymer cell frame. Optionally, a gasket 720 may be placed near the notch on the surface of the polymeric component 700. Then, a metal component 710 is placed in intimate contact with the surface of the gasket 720 and / or the polymeric component 700. The metal component 710 may be, for example, a bipolar plate. Optionally, the gasket 720 may have spring or spring properties (for example, it may be an elastomeric gasket). The metal component 710 is compressed onto the surface of the gasket 720 and / or the polymeric component 700, so that its edge sits above the notch 730. This may be done using a “clamp plate” 740 (as shown in the top right of FIG. 4(b)). Next, a "roll-forming" tool 750 (as shown in the top right of FIG. 4(b)) is used to bend the end of the metal part 710 into the notch, as shown in area 731. In doing so, the metal part can be sealed and fixed to the polymeric part 700 (e.g., a metal bipolar plate can be sealed and fixed to a polymeric cell frame). In this case, the integrity of the polymer-metal seal is maintained by the tension applied by the two external roll-formed joints on the metal part 710.

[0225] Preferably, the following polymer-metal joints may be used in the above cell and cell stack architectures and techniques, but are not limited to these: (1) "Continuous edge heat staking" bonding (2) "Textured metal-polymer" bonding, (3) “Roll-formed” joints.

[0226] Other preferred embodiment examples include, but are not limited to, polymer-metal and polymer-polymer bonding involving the use of: (1) Chemical bonding with or without chemical adhesion promoting materials, including the application of: i. Various types of adhesives and glues, including but not limited to: 1. Glues by chemical composition, including epoxy glue, polyurethane glue, polyimide glue, cyanoacrylate glue, polyvinyl acetate glue; 2. Adhesives by physical form, including adhesive pastes, adhesive gums, adhesive films, adhesive cements, adhesive resins, adhesive binders, elastomeric adhesives, wet adhesives; 3. Adhesives by classification, including contact adhesives, reactive adhesives, single-component reactive adhesives, two-component or multi-component reactive adhesives, hot melt adhesives, pressure sensitive adhesives, thermosetting adhesives; 4. Adhesives by their ability to withstand loads, including structural adhesives, non-structural adhesives, and semi-structural adhesives; (2) Dissolution and rematerialization of polymers, including but not limited to: i. Solvent welding; (3) Melting or softening of polymers, with or without wetting agents to promote polymer flow, including but not limited to: i. Heat welding, ii. Hot plate or platen welding; iii. Ultrasonic or vibration welding; iv. Laser welding or laser beam welding; v. Hot air welding, vi. Spin welding, vii. Friction welding, viii. Frequency, high frequency, or radio frequency welding; ix. Infrared or non-contact welding; x.Speed ​​tip welding, xi. Extrusion welding; xii. Contact welding, xiii. Induction welding; and xiv.Injection welding.

[0227] It should be understood that the above list of bonds is not exhaustive: all forms of polymer-polymer and polymer-metal bonds may be used in preferred embodiments.

[0228] Metal-to-metal bonding of preferred embodiments In various other example aspects, the embodiments relate to intermetallic bonds that may be used in the cell and cell stack architectures and techniques described above. Intermetallic welding is a particularly preferred form of intermetallic bonding. As used herein, "intermetallic welding" refers to any form of metallurgical intermetallic bonding that may be considered to involve welding, including, but not limited to, fusion welding and pressure welding.

[0229] Preferred example embodiments include metal-to-metal bonds including, but not limited to: (1) Mechanical bonds, including but not limited to bonds formed by: i. Riveting, ii. Caulking; iii. bolting; iv. Shrink fit, v. Bending; (2) Chemical bonds, including but not limited to bonds formed by: i. Bonding, including bonding of metals with glues, including conductive glues; (3) Metallurgical bonds, including but not limited to bonds formed by: i. Fusion welding, including: 1. Electric energy: arc welding, electron beam welding, 2. Chemical energy: gas welding, 3. Light energy: laser welding; ii. Pressure welding, including: 1. Electric energy: resistance welding (including resistance spot welding, projection welding, seam welding, upset welding, and flash welding); 2. Chemical energy: explosive welding, 3. Mechanical energy: cold welding, friction welding, friction stir welding, ultrasonic welding, diffusion welding; iii. Brazing / soldering, including: 1. Electric energy: induction brazing, soft soldering, soldering, 2. Chemical energy: torch brazing, flame brazing, 3. Light energy: light beam brazing, laser brazing, 4. "Soft soldering", 5. "Hard soldering."

[0230] It should be understood that the above list of bonds is not exhaustive: all forms of metal-to-metal bonds may be used in preferred embodiments.

[0231] Electrical energy and electrosynthesis cells and reactions In further embodiments, the following is provided: (i) Any of the above exemplary cells in an alkaline water electrolyser or alkaline fuel cell, where the electrolyte is a hydroxide with a pH above 10. (ii) Any of the preceding exemplary cells having an electrode separator less than 0.2 mm thick. (iii) Any of the foregoing exemplary cells having a clamping force on the electrodes that compresses the electrodes against the inter-electrode separator in excess of 2 bar. (iv) Any of the preceding exemplary cells in an alkaline water electrolyzer or alkaline fuel cell where the electrolyte is hydroxide with a pH greater than 10 and has an electrode separator less than 0.2 mm thick. (v) Any of the foregoing exemplary cells in an alkaline water electrolyser or alkaline fuel cell where the electrolyte is hydroxide with a pH greater than 10 and having a clamping force on the electrodes that compresses the electrodes against the inter-electrode separator in excess of 2 bar. (vi) Any of the foregoing exemplary cells in an alkaline water electrolyser or alkaline fuel cell where the electrolyte is hydroxide with a pH greater than 10, having a clamping force on the electrodes that compresses the electrodes against the inter-electrode separator greater than 2 bar, and having an electrode separator less than 0.2 mm thick.

[0232] Preferably, but not limited to, the liquid electrolyte used in the above example embodiments comprises a hydroxide salt and has a pH of at least 10. Optionally, the liquid electrolyte used in the example embodiments has a pH of less than 10.

[0233] Preferably, the cells and cell stacks having the above characteristics are electrical energy or electrosynthesis cells or cell stacks such as: (i) hydrogen-oxygen fuel cells, including polymer electrolyte membrane (PEM) fuel cells or alkaline fuel cells; (ii) direct alcohol fuel cells, including direct methanol or direct ethanol fuel cells; (iii) phosphoric acid fuel cells; or (iv) ammonia fuel cells.

[0234] Preferably, the cells and cell stacks having the above characteristics are electrosynthesis cells or cell stacks such as (i) water electrolysers, (ii) chlor-alkali electrolysers, (iii) nitrogen reduction cells for ammonia production, or (iv) CO2 electrolysers (including integrated carbon capture and CO2 electrolysers).

[0235] Preferably, the cells and cell stacks having the above characteristics are capillary-powered electrical energy or electrosynthesis cells or cell stacks of the type described in International Publication Nos. WO 2022056603, WO 2022056604, WO 2022056605, and WO 2022056606, which are incorporated herein by reference.

[0236] Combination of features According to various non-limiting example embodiments, the following points disclose feature combinations that provide various example cells, multi-cell stacks, systems, and / or example methods of operation. 1. A polymer cell frame; A first electrode and a second electrode; an interelectrode separator disposed between the first electrode and the second electrode; a metal bipolar plate component; An electrical energy or electrosynthesis cell comprising: An electrical energy or electrosynthesis cell in which a polymeric cell frame is sealed to a metal bipolar plate compression component. 2. An electric energy or electrosynthesis cell according to point 1, in which the bipolar plate component is a compression component. 3. The electric energy or electrosynthesis cell of any one of the preceding points, wherein the bipolar plate is disposed adjacent to the first electrode. 4. An electric energy or electrosynthesis cell according to any one of the preceding points, wherein the seal between the polymer cell frame and the metal bipolar plate component is formed by a polymer-metal bond. 5. An electric energy or electrosynthesis cell according to any one of the preceding points, wherein at least one polymeric structural positioning component positions the metallic bipolar plate component relative to the polymeric cell frame. 6. The electric energy or electrosynthesis cell of any one of the preceding points, wherein the seal between the polymeric cell frame and the metallic bipolar plate component is formed by one or more polymer-to-polymer bonds between at least one polymeric structural positioning component and the polymeric cell frame, and at least one polymeric structural positioning component mechanically holding the metallic bipolar plate component relative to the polymeric cell frame. 7. The electric energy or electrosynthesis cell of any one of the preceding points, wherein the first electrode and the second electrode are disposed within a polymeric cell frame. 8. The electric energy or electrosynthesis cell of any one of the preceding points, wherein the polymeric cell frame includes a window cutout, the first electrode and the second electrode being disposed within the window cutout. 9. The electric energy or electrosynthesis cell of any one of the preceding points, wherein the inter-electrode separator is a polymeric inter-electrode separator. 10. An electric energy or electrosynthesis cell according to any one of the preceding points, wherein the polymeric cell frame is joined to the polymeric inter-electrode separator via an inter-polymer bond. 11. The electric energy or electrosynthesis cell according to any one of the preceding points, wherein the first electrode is a first metal electrode. 12. An electric energy or electrosynthesis cell according to any one of the preceding points, wherein a metallic bipolar plate component is bonded to a first metallic electrode, thereby forming a metal-to-metal bonded assembly. 13. The electric energy or electrosynthesis cell of any one of the preceding points, further comprising a metallic porous transport layer disposed between the metallic bipolar plate component and the first metallic electrode. 14. The electric energy or electrosynthesis cell of any one of the preceding points, wherein the metal-to-metal bonded assembly further comprises a metallic porous transport layer bonded to the metallic bipolar plate component and the first metallic electrode. 15. The electric energy or electrosynthesis cell of any one of the preceding points, further comprising a second metallic bipolar plate component. 16. The electric energy or electrosynthesis cell of any one of the preceding points, wherein the second metallic bipolar plate is a compressive component. 17. The electric energy or electrosynthesis cell of any one of the preceding points, wherein a second bipolar plate is disposed adjacent to the second electrode on the opposite side from the interelectrode separator. 18. An electric energy or electrosynthesis cell according to any one of the preceding points, wherein the polymeric cell frame is sealed to a second metallic bipolar plate component. 19. An electric energy or electrosynthesis cell according to any one of the preceding points, wherein the seal between the polymer cell frame and the second metallic bipolar plate component is formed by a polymer-metal bond. 20. An electric energy or electrosynthesis cell according to any one of the preceding points, wherein at least one further polymeric structure positioning component positions a second metallic bipolar plate component relative to the polymeric cell frame. 21. An electric energy or electrosynthesis cell according to any one of the preceding points, wherein the seal between the polymeric cell frame and the second metallic bipolar plate component is formed by one or more further polymer-to-polymer bonds between the at least one further polymeric structural positioning component and the polymeric cell frame, and at least one further polymeric structural positioning component that mechanically holds the second metallic bipolar plate component relative to the polymeric cell frame. 22. The second electrode is a second metal electrode; 13. The electric energy or electrosynthesis cell of any one of the preceding points, wherein a second metallic bipolar plate component is bonded to a second metallic electrode, thereby forming a second metal-to-metal bonded assembly. 23. The electric energy or electrosynthesis cell of any one of the preceding points, further comprising a second metallic porous transport layer disposed between the second metallic bipolar plate component and the second metallic electrode. 24. The electric energy or electrosynthesis cell of any one of the preceding points, wherein the second intermetallic bonded assembly further comprises a second metallic porous transport layer bonded to the second metallic bipolar plate component and the second metallic electrode. 25. The electric energy or electrosynthesis cell of any one of the preceding points, wherein the polymer-metal bond is selected from the group of continuous edge heat staking bonds, textured metal-polymer bonds, roll formed bonds, chemical bonds, polymer dissolution and rematerialization, and polymer melting or softening. 26. An electric energy or electrosynthesis cell according to any one of the preceding points, wherein the cell is sealed. 27. An electric energy or electrosynthesis cell according to any one of the preceding points, wherein the cell is internally compressed. 28. An electric energy or electrosynthesis cell according to any one of the preceding points, wherein an inter-electrode separator is disposed within a window cutout and bonded to a polymeric cell frame. 29. A polymer cell frame; A first electrode and a second electrode; an interelectrode separator disposed between the first electrode and the second electrode; a metallic porous transport layer compression component disposed adjacent the first electrode opposite the interelectrode separator; a metallic bipolar plate disposed adjacent the metallic porous transport layer compressive component opposite the first electrode; An electrical energy or electrosynthesis cell comprising: An electrical energy or electrosynthesis cell, wherein at least one polymeric structural positioning component positions the metallic bipolar plate relative to the polymeric cell frame. 30. The electric energy or electrosynthesis cell of any one of the preceding points, wherein at least one polymeric structural positioning component partially surrounds the metallic bipolar plate and the first electrode. 31. An electric energy or electrosynthesis cell according to any one of the preceding points, wherein the polymeric cell frame is sealed to the metallic porous transport layer component. 32. An electric energy or electrosynthesis cell according to any one of the preceding points, wherein the joint between the metal bipolar plate and the at least one polymeric structure positioning component is sealed. 33. An electric energy or electrosynthesis cell according to any one of the preceding points, wherein a gasket is disposed at the joint between the metal bipolar plate and the polymeric cell frame. 34. An electric energy or electrosynthesis cell according to any one of the preceding points, wherein the metallic bipolar plate is a compressive component. 35. An electric energy or electrosynthesis cell according to any one of the preceding points, wherein the metal bipolar plate compression component is provided as a waffle structure. 36. The electric energy or electrosynthesis cell according to any one of the preceding points, wherein the first electrode is welded to at least some of the lands of the waffle structure. 37. An electric energy or electrosynthesis cell according to any one of the preceding points, wherein once assembled, the metal bipolar plate compression component has the properties of a spring. 38. An electric energy or electrosynthesis cell according to any one of the preceding points, wherein the metallic bipolar plate compression component exerts a clamping force compressing its electrodes against the interelectrode separator. 39. An electric energy or electrosynthesis cell according to any one of the preceding points, wherein the metallic porous transport layer compression component exerts a clamping force compressing an electrode thereof against an interelectrode separator. 40. An electric energy or electrosynthesis cell according to one of the preceding two points, wherein the clamping force exerted internally within the cell by the metallic bipolar plate compression component on the first electrode, which when assembled compresses the first electrode against the interelectrode separator, is greater than 0.01 bar, greater than 0.02 bar, greater than 0.03 bar, greater than 0.04 bar, greater than 0.05 bar, greater than 0.075 bar, greater than 0.1 bar, greater than 0.2 bar, greater than 0.3 bar, greater than 0.5 bar, greater than 0.75 bar, greater than 1 bar, greater than 2 bar, greater than 3 bar, greater than 4 bar, greater than 5 bar, greater than 10 bar, greater than 15 bar, or greater than 20 bar. 41. An electric energy or electrosynthesis cell according to any one of the preceding points, further comprising a tolerance compensation feature. 42. An electric energy or electrosynthesis cell according to any one of the preceding points, wherein the tolerance compensation feature is a channel, groove, slot, or tongue. 43. An electric energy or electrosynthesis cell according to any one of the preceding points, wherein the tolerance compensation feature is a push-fit engaging component, a tongue and groove, or a locating pin and hole. 44. An electric energy or electrosynthesis cell according to any one of the preceding points, wherein the thickness of the inter-electrode separator is less than 0.35 mm, less than 0.2 mm, less than 0.1 mm, less than 0.05 mm, or less than 0.025 mm. 45. A cell stack comprising a plurality of electric energy or electrosynthesis cells according to any one of the preceding points. 46. ​​A cell stack according to point 45, in which the polymer cell frame of one cell in the cell stack is joined to the polymer cell frame of an adjacent cell in the cell stack. 47. A cell stack according to point 45 or 46, in which the polymer cell frame of one cell in the cell stack is welded to the polymer cell frame of an adjacent cell in the cell stack. 48. A cell stack according to any one of points 45 to 47, wherein the waffle structure of the metal bipolar plate compression component of one cell in the cell stack interdigitates with the waffle structure of the metal bipolar plate compression component of an adjacent cell in the cell stack. 49. A cell stack according to any one of points 45 to 48, wherein the waffle structure of the metal bipolar plate compression component of one cell in the cell stack is welded to the waffle structure of the metal bipolar plate compression component of an adjacent cell in the cell stack. 50. A cell stack according to any one of points 45 to 49, which is a filter press type cell stack. 51. A cell stack according to any one of points 45 to 50, wherein the liquid inlet headers of the cells in the cell stack are pressurized to a pressure higher than the liquid in each cell, and the liquid outlet headers of the cells in the cell stack are pressurized to a pressure lower than the liquid in each cell. 52. A cell stack according to any one of points 45 to 51, wherein the compression pressure applied to the cell stack is greater than 0.01 bar, greater than 0.02 bar, greater than 0.03 bar, greater than 0.04 bar, greater than 0.05 bar, greater than 0.075 bar, greater than 0.1 bar, greater than 0.2 bar, greater than 0.3 bar, greater than 0.5 bar, greater than 0.75 bar, greater than 1 bar, greater than 2 bar, greater than 3 bar, greater than 4 bar, greater than 5 bar, greater than 10 bar, or greater than 20 bar.

[0237] Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise" and variations such as "comprises" or "comprising" will be understood to mean the inclusion of a stated integer or step or group of integers or steps but not to the exclusion of other integers or steps or groups of integers or steps.

[0238] Additionally, optional embodiments may be said to broadly consist of any or all combinations of two or more of the components, elements, and features referred to or shown in this specification, either individually or collectively, and where specific integers having known equivalents in the art to which the invention pertains are referred to herein, such known equivalents are deemed to be incorporated herein as if individually set forth.

[0239] Although preferred embodiments have been described in detail, it should be understood that many modifications, changes, substitutions, or alterations will be apparent to those skilled in the art without departing from the scope of the invention.

Claims

1. A polymer cell frame; A first electrode and a second electrode; an interelectrode separator disposed between the first electrode and the second electrode; a metallic bipolar plate compression component disposed adjacent to the first electrode; An electrical energy or electrosynthesis cell comprising: An electrical energy or electrosynthesis cell, wherein the polymeric cell frame is sealed to the metallic bipolar plate compression component.

2. 10. The electric energy or electrosynthesis cell of claim 1, wherein a seal between the polymer cell frame and the metal bipolar plate compression component is formed by a polymer-metal bond.

3. 10. The electric energy or electrosynthesis cell of claim 1, wherein at least one polymeric structural positioning component positions said metallic bipolar plate compression component relative to said polymeric cell frame.

4. 4. The electric energy or electrosynthesis cell of claim 3, wherein a seal between the polymer cell frame and the metallic bipolar plate compression component is formed by one or more polymer-to-polymer bonds between the at least one polymer structural positioning component and the polymer cell frame, the at least one polymer structural positioning component mechanically holding the metallic bipolar plate compression component relative to the polymer cell frame.

5. 5. The electric energy or electrosynthesis cell of any one of claims 1 to 4, wherein the first electrode is a first metal electrode and the metallic bipolar plate compression component is welded to the first metal electrode, thereby forming a metal-to-metal bonded assembly.

6. 6. The electric energy or electrosynthesis cell of claim 5, further comprising a metallic porous transport layer disposed between said metallic bipolar plate compression component and said first metallic electrode.

7. 7. An electric energy or electrosynthesis cell according to any one of claims 1 to 6, wherein the metallic bipolar plate compression component is provided as a waffle structure.

8. 8. The electric energy or electrosynthesis cell of claim 7, wherein the first electrode is welded to at least some of the lands of the waffle structure.

9. 9. An electric energy or electrosynthesis cell according to claim 7 or 8, wherein once assembled, the metallic bipolar plate compression components have the properties of a spring.

10. 10. The electric energy or electrosynthesis cell of any one of claims 1 to 9, wherein the metallic bipolar plate compression component exerts a clamping force on the first electrode to compress the first electrode against the inter-electrode separator.

11. 11. An electrical energy or electrosynthesis cell according to any one of claims 1 to 10, wherein the cell is internally compressed.

12. 12. The electric energy or electrosynthesis cell of any one of claims 1 to 11, wherein a clamping force exerted internally within the cell by the metallic bipolar plate compression component on the first electrode which when assembled compresses the first electrode against the interelectrode separator is greater than 0.01 bar, greater than 0.02 bar, greater than 0.03 bar, greater than 0.04 bar, greater than 0.05 bar, greater than 0.075 bar, greater than 0.1 bar, greater than 0.2 bar, greater than 0.3 bar, greater than 0.5 bar, greater than 0.75 bar, greater than 1 bar, greater than 2 bar, greater than 3 bar, greater than 4 bar, greater than 5 bar, greater than 10 bar, greater than 15 bar, or greater than 20 bar.

13. 13. The electrical energy or electrosynthesis cell of any one of claims 1 to 12, wherein the inter-electrode separator has a thickness of less than 0.35 mm, less than 0.2 mm, less than 0.1 mm, less than 0.05 mm, or less than 0.025 mm.

14. 14. The electric energy or electrosynthesis cell of any one of claims 1 to 13, further comprising a second metallic bipolar plate compression component positioned adjacent the second electrode on an opposite side from the inter-electrode separator.

15. the second electrode is a second metal electrode; 15. The electric energy or electrosynthesis cell of claim 14, wherein the second metallic bipolar plate compression component is welded to the second metallic electrode, thereby forming a second metal-to-metal bonded assembly.

16. 15. The electric energy or electrosynthesis cell of claim 14, wherein the polymer cell frame is sealed to the second metal bipolar plate compression component.

17. 15. The electric energy or electrosynthesis cell of claim 14, wherein a seal between the polymer cell frame and the second metal bipolar plate compression component is formed by a polymer-metal bond.

18. 20. The electric energy or electrosynthesis cell of claim 17, wherein at least one additional polymeric structural positioning component positions the second metallic bipolar plate compression component relative to the polymeric cell frame.

19. 20. The electric energy or electrosynthesis cell of claim 18, wherein a seal between the polymeric cell frame and the second metallic bipolar plate compression component is formed by one or more additional polymer-to-polymer bonds between the at least one additional polymeric structural positioning component and the polymeric cell frame, and the at least one additional polymeric structural positioning component mechanically holding the second metallic bipolar plate compression component relative to the polymeric cell frame.

20. 20. The electric energy or electrosynthesis cell of claim 2 or 17, wherein the polymer-metal bond is selected from the group of continuous edge heat staking bonds, textured metal-polymer bonds, roll formed bonds, chemical bonds, polymer dissolution and rematerialization, and polymer melting or softening.

21. 21. An electric energy or electrosynthesis cell according to any one of claims 1 to 20, wherein the first electrode and the second electrode are disposed within the polymeric cell frame.

22. 22. An electric energy or electrosynthesis cell according to any one of claims 1 to 21, wherein the polymeric cell frame includes a window cutout, and the first electrode and the second electrode are disposed within the window cutout.

23. 23. The electrical energy or electrosynthesis cell of any one of claims 1 to 22, wherein the interelectrode separator is a polymeric interelectrode separator.

24. 24. The electric energy or electrosynthesis cell of claim 23, wherein the polymeric cell frame is joined to the polymeric inter-electrode separator via a polymer-polymer bond.

25. 25. The electrical energy or electrosynthesis cell of any one of claims 1 to 24, wherein the cell is sealed.

26. 23. The electric energy or electrosynthesis cell of claim 22, wherein the inter-electrode separator is disposed within the window cutout and bonded to the polymeric cell frame.

27. 27. The electric energy or electrosynthesis cell of any one of claims 1 to 26, further comprising a tolerance compensation feature.

28. 30. The electric energy or electrosynthesis cell of claim 27, wherein the tolerance compensation feature is a channel, groove, slot, or tongue.

29. 28. The electric energy or electricity synthesis cell of claim 27, wherein the tolerance compensation features are push-fit engaging components, tongue and grooves, or locating pins and holes.

30. A cell stack comprising a plurality of the electric energy or electrosynthesis cells according to any one of claims 1 to 29.

31. The cell stack of claim 30 , wherein the polymer cell frame of one cell in the cell stack is bonded to the polymer cell frame of an adjacent cell in the cell stack.

32. The cell stack of claim 30 , wherein the polymer cell frame of one cell in the cell stack is welded to the polymer cell frame of an adjacent cell in the cell stack.

33. 33. The cell stack of any one of claims 30 to 32 and the electric energy or electrosynthesis cell of claim 7, wherein the waffle structure of the metallic bipolar plate compression component of one cell in the cell stack interdigitates with the waffle structure of the metallic bipolar plate compression component of an adjacent cell in the cell stack.

34. 33. The cell stack of any one of claims 30 to 32 and the electric energy or electrosynthesis cell of claim 7, wherein the waffle structure of the metallic bipolar plate compression component of one cell in the cell stack is welded to the waffle structure of the metallic bipolar plate compression component of an adjacent cell in the cell stack.

35. The cell stack according to any one of claims 30 to 34, which is a filter press type cell stack.

36. A cell stack according to any one of claims 30 to 35, wherein liquid inlet headers of the cells in the cell stack are pressurized to a pressure higher than the liquid in each cell, and liquid outlet headers of the cells in the cell stack are pressurized to a pressure lower than the liquid in each cell.

37. A polymer cell frame; A first electrode and a second electrode; an interelectrode separator disposed between the first electrode and the second electrode; a metallic porous transport layer compressible component disposed adjacent the first electrode opposite the interelectrode separator; a metallic bipolar plate disposed adjacent the metallic porous transport layer compressive component opposite the first electrode; An electrical energy or electrosynthesis cell comprising: At least one polymeric structural positioning component positions said metallic bipolar plate relative to said polymeric cell frame, an electrical energy or electrical synthesis cell.

38. 38. The electric energy or electrosynthesis cell of claim 37, wherein the at least one polymeric structural positioning element partially surrounds the metallic bipolar plate and the first electrode.

39. 40. The electric energy or electrosynthesis cell of claim 37 or 38, wherein the polymeric cell frame is sealed to the metallic porous transport layer compression component.

40. 40. The electric energy or electrosynthesis cell of any one of claims 37 to 39, wherein the joint between said metallic bipolar plate and said at least one polymeric structural positioning component is sealed.

41. 41. The electric energy or electrosynthesis cell of claim 40, wherein a gasket is disposed at the joint between the metal bipolar plate and the polymeric cell frame.

42. 42. An electric energy or electrosynthesis cell according to any one of claims 37 to 41, wherein the metallic bipolar plate is a compression component.

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