Double-sided sealed gas diffusion electrode

Abstract

FIELD: energy engineering.SUBSTANCE: group of inventions relates to devices, systems and methods for long-term and ultra-long-term, low-cost energy storage. Systems and methods according to various embodiments provide double-sided sealed gas diffusion electrode (GDE) assemblies. In some embodiments, a double-sided sealed gas diffusion electrode (GDE) assembly includes active electrode layers on two opposite sides of the assembly. Various embodiments provide architecture and / or methods for sealing GDE assemblies. In various embodiments, the GDE assemblies are used in devices. In various embodiments, the devices are primary or secondary batteries. In various embodiments, said devices may be suitable for storing energy. For example, the double-sided sealed GDE assemblies according to various embodiments form the cathode electrodes (sometimes referred to as air electrodes) of a battery, such as a metal-air battery.EFFECT: long-term and ultra-long-term large-scale energy storage.46 cl, 30 dwg

Description

RELATED APPLICATIONS

[0001] This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 304,425, entitled "BIFACIAL SEALED GAS DIFFUSION ELECTRODE," filed January 28, 2022, the entire contents of which are incorporated herein by reference for all purposes.BACKGROUND

[0002] Energy storage technologies play a critical role in power grids; at the most basic level, these energy storage devices provide smoothing to better match generation and grid demand. The services provided by energy storage devices benefit power grids across a variety of time scales, from milliseconds to years. Energy storage technologies currently exist that can support timescales from milliseconds to hours, but there is a need for long-term and ultra-long-term energy storage systems (at least 8 hours in total).

[0003] Metal-air batteries are attractive options for electrochemical energy storage due to their low cost and the abundance of air as a reactant for energy storage reactions. Many challenges in developing metal-air batteries are related to the mechanical architecture of the cells. Some architectures suitable for small-scale storage, such as those used for zinc-air hearing aid batteries, are unsuitable for large-scale energy storage, such as grid-connected applications.

[0004] This "Background of the Invention" section is intended to introduce various aspects of the art that relate to embodiments of the present inventions. Therefore, the preceding discussion in this section is intended to provide a better understanding of the present inventions and should not be construed as an admission of prior art. SUMMARY OF THE INVENTION

[0005] Systems and methods according to various embodiments can provide double-sided sealed gas diffusion electrode (GDE) assemblies. In various embodiments, the double-sided GDE assemblies can be GDE assemblies for use in devices. In various embodiments, the devices can be primary or secondary batteries. In various embodiments, the devices can be suitable for energy storage. BRIEF DESCRIPTION OF THE FIGURES

[0006] The accompanying drawings, which are incorporated herein and form a part of this specification, illustrate examples of embodiments of the invention and, together with the general description given above and the detailed description given below, serve to explain the features of the claims.

[0007] FIG. 1 shows a portion of a battery according to an embodiment.

[0008] FIG. 2 is a schematic diagram showing a battery having a submerged electrode for an oxygen reduction reaction (ORR) in accordance with various embodiments of the present invention.

[0009] FIG. 3A is a sectional side view of an exemplary electrode assembly.

[0010] FIG. 3B is a schematic diagram showing a method for manufacturing a gas diffusion (GD) electrode with a layered structure in accordance with various embodiments of the present invention.

[0011] FIG. 3C is a perspective view of the DH electrode assembly, which includes a DH electrode with a layered structure mounted on a support frame.

[0012] FIGS. 4A-4D are front, top, bottom, and side views, respectively, of a sealed gas diffusion electrode (GDE) assembly according to an embodiment of the present invention.

[0013] FIG. 5A is a perspective view of a mold that can be used to manufacture a layered GD electrode having a desired three-dimensional shape.

[0014] FIGS. 5B and 5C schematically show a method for manufacturing a double-sided sealed GDE assembly using a "two-step" lamination and sealing process in accordance with an embodiment of the present invention.

[0015] FIG. 5D is a schematic diagram showing a method for manufacturing a double-sided sealed GDE assembly using an alternative two-step lamination and sealing process in accordance with an embodiment of the present invention.

[0016] FIG. 6 shows a GDE assembly that includes a sealing material located at the edges of the GDE assembly in accordance with an embodiment of the present invention.

[0017] FIG. 7 is a schematic diagram showing a method for manufacturing a double-sided sealed GDE assembly using a "one-step" lamination and sealing process in accordance with an embodiment of the present invention.

[0018] FIG. 8 is a schematic illustration of a method for manufacturing a double-sided sealed GDE assembly using an alternative "one-step" lamination and sealing process in accordance with an embodiment of the present invention.

[0019] FIG. 9 is a side sectional view of a mold taken along line A-A' in FIG. 8, illustrating a method for manufacturing a GDE assembly using a one-step lamination and sealing process according to an embodiment of the present invention.

[0020] FIG. 10 schematically shows an alternative one-step lamination and sealing process that can be used to simultaneously produce multiple GDE assemblies in accordance with another embodiment of the present invention.

[0021] FIGS. 11A-11C are sectional views of exemplary GDE assemblies having contoured outer surfaces in accordance with an embodiment of the present invention.

[0022] FIGS. 12A-12C show a GDE assembly and a process for producing a GDE assembly having a reduced active area according to an embodiment of the present invention.

[0023] FIGS. 13A-13C show a GDE assembly and a process for producing a GDE assembly having a reduced active area according to another embodiment of the present invention.

[0024] FIGS. 14A and 14B are top and side views, respectively, of a GDE assembly according to another embodiment of the present invention.

[0025] FIG. 15A and 15B are front and top views, respectively, of a double-sided sealed GDE assembly that includes an insert in the inner chamber of the GDE assembly, according to an embodiment of the present invention.

[0026] FIGS. 16A-16C show a method of manufacturing a double-sided sealed GDE assembly containing an internal conductive element, according to another embodiment of the present invention.

[0027] FIGS. 17A and 17B show a method of manufacturing a double-sided sealed GDE assembly comprising a pair of planar GD electrodes attached to a support frame, in accordance with an embodiment of the present invention.

[0028] FIG. 18A is a side view of a double-sided sealed GDE assembly comprising a pair of planar GD electrodes attached to a support frame, according to an embodiment of the present invention.

[0029] FIGS. 18B and 18C are side views of a double-sided sealed GDE assembly comprising a pair of planar GD electrodes attached to a support frame, according to another embodiment of the present invention.

[0030] FIGS. 19A and 19B show a method for manufacturing double-sided sealed GDE assemblies in accordance with the embodiment of the invention illustrated in FIGS. 18B and 18C.

[0031] FIG. 20A and 20B show a method for producing a large-area layered GD electrode using an interlocking weld according to an embodiment of the present invention.

[0032] FIGS. 21A-21E show a method of manufacturing a double-sided sealed gas turbine assembly using a "flat pressing" process.

[0033] FIGS. 22-30 show various exemplary systems in which one or more aspects of various embodiments may be used as part of large-scale energy storage systems. EMBODIMENTS OF THE INVENTION

[0034] Various embodiments of the invention are described in detail with reference to the accompanying drawings. Wherever possible, the same reference numerals are used throughout the drawings to refer to the same or similar parts. References to specific examples and implementations are intended for illustrative purposes and are not intended to limit the scope of the claims. The following description of embodiments of the invention is not intended to limit the invention to these embodiments, but rather to enable a person skilled in the art to make and use the present invention.

[0035] In this document, unless otherwise stated, room temperature is 25°C, and the standard temperature and pressure are 25°C and 1 atmosphere. Unless otherwise stated, all measurements, measurement results, physical properties, and values ​​that depend on temperature, pressure, or both are given at standard ambient temperature and pressure.

[0036] Generally, unless otherwise specified, the term "about" as used herein is intended to cover the deviation or range of ±10%, experimental or instrumental error associated with obtaining the stated value, and preferably the greater of them.

[0037] In this document, unless otherwise specified, the listing of ranges of values ​​in this document is intended solely to serve as a shortcut for individually referencing each individual value within the range. In this document, unless otherwise specified, each individual value within a range is included in the specification as if it were separately listed herein.

[0038] The following examples are provided to illustrate various embodiments of the systems and methods of the present invention. These examples are illustrative, possibly predictive, and should not be construed as limiting or otherwise limiting the scope of the present invention.

[0039] It should be noted that it is not necessary to provide or discuss the theory underlying the new and innovative processes, materials, operating parameters, or other useful characteristics and properties that are the subject of or associated with embodiments of the present invention. However, various theories are presented herein to further develop the art. The theories put forward herein, and unless expressly stated otherwise, in no way limit, reduce, or narrow the scope of the claims provided by the claimed inventions. These theories are not necessary, and these theories are not used in practice for the application of the present invention.Furthermore, it should be understood that the present inventions may lead to new and previously unknown theories explaining the functional features of embodiments of the methods, articles, materials, devices and systems according to the present invention; and such later developed theories should not limit the scope of the claims provided by the present inventions.

[0040] Various embodiments of systems, equipment, technologies, methods, actions, and operations described in this document are applicable to various other actions and in other fields in addition to those described herein. In addition, these embodiments are applicable, for example, with other equipment or activities that may be developed in the future; and with existing equipment or actions that may be partially modified based on the teachings of this description. In addition, the various embodiments and examples described in this description are applicable to each other, in whole or in part, and in various and diverse combinations. Thus, for example, the configurations presented in the various embodiments in this description can be applied to each other.For example, the components of an embodiment of the invention having A, A' and B, and the components of an embodiment of the invention having A", C and D, are applicable to each other in various combinations, such as A, C, D and A", C and D, etc., in accordance with the teachings of the present disclosure. Accordingly, the scope of the claims provided by the present inventions should not be limited to a particular embodiment of the invention, configuration or arrangement that is set forth in a particular embodiment of the invention, example or in an embodiment of the invention in a particular figure.

[0041] Embodiments of the present invention include devices, systems, and methods for long-term and ultra-long-term, low-cost energy storage. In the present description, the terms "long-term," "ultra-long-term," and similar terms, unless explicitly stated otherwise, should be given the broadest possible meaning, and these terms include energy storage periods of 8 hours or more, for example, energy storage periods of 8 hours, energy storage periods from 8 to 20 hours, energy storage periods of 20 hours, energy storage periods from 20 hours to 24 hours, energy storage periods of 24 hours, energy storage periods from 24 hours to a week, energy storage periods from a week to a year (for example, from several days to several weeks to several months), etc., and these terms also include long-term energy storage systems.Furthermore, the terms "long-lasting" and "ultra-long-lasting," "energy storage cells" including "electrochemical cells," and similar terms, unless expressly stated otherwise, shall be given the broadest possible interpretation; and such terms include electrochemical cells that may be designed to store energy for several days, weeks, or seasons.

[0042] Typically, in an embodiment of the invention, the long-term energy storage cell is a long-term electrochemical cell.In general, a given long-term electrochemical storage cell stores electric energy generated by an electric power generation system when: (i) for a given generation, the energy source or fuel, as well as combinations and variations thereof, is available, abundant, and inexpensive; (ii) when the required capacity or electricity demand from the electric power grid, customer, or other user is less than the amount of electric energy generated by the electric power generation system, the price paid for providing such capacity to the grid, customer, or other user is below the economically efficient point for producing such energy (e.g., the cost of production exceeds the market price for electricity), as well as combinations and variations thereof; and (iii) when combinations and variations of (i) and (ii), as well as other reasons, are realized.This electrical energy, stored in a long-term storage electrochemical cell, is then distributed to the grid, a consumer, or another user when economically feasible or necessary. For example, electrochemical cells can be designed to store energy generated by solar cells during the summer months, when sunlight is abundant and solar energy production exceeds grid demand, and release the stored energy during the winter months, when sunlight is insufficient to meet grid demand.

[0043] FIG. 1 shows a portion of a battery 100 according to an embodiment, such as a metal-air battery. The battery 100 (for example, a metal-air battery) includes a first negative electrode 110 (usually referred to as an anode), a first positive electrode 120 (usually referred to as a cathode), an electrolyte 140, and a housing 170.

[0044] In various embodiments, electrolyte 140 is liquid. In various embodiments, anode 110 is solid, and electrolyte 140 is excluded from the anode. In various other embodiments, anode 110 is porous, and electrolyte 140 is geometrically interspersed with anode 110, creating a large interfacial surface area for the reaction. In various embodiments, cathode 120 is porous, and electrolyte is geometrically interspersed with anode 110, creating a large interfacial surface area for the reaction. In various embodiments, cathode 120 is located at the interface between the electrolyte and free space 105 for the gaseous phase. In various embodiments, the free space for the gaseous phase is hermetically sealed in housing 170.In various other embodiments of the invention, the housing 170 is not hermetically sealed and the free space for the gaseous phase is an open system that can freely exchange mass with the environment.

[0045] The anode 110 may be made of a metal or a metal alloy, such as lithium (Li), sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), silicon (Si), aluminum (Al), zinc (Zn) or iron (Fe); or alloys essentially consisting of one or more of the above-mentioned metal elements, such as an aluminum alloy or an iron alloy (e.g., FeAl, FeZn, FeMg, etc.), which can undergo an oxidation reaction for discharge. Therefore, in this document, the anode 110 may be referred to as a metal electrode. In certain embodiments of the invention, the battery is rechargeable, and when the battery is charged, the metal electrode undergoes a reduction reaction. The anode 110 may be a solid, including a dense or porous solid, or a mesh, or a foam, or a particle, or an accumulation of particles, or may be a slurry, ink, suspension, or paste, placed within the housing 170.In various embodiments, the composition of anode 110 can be selected such that anode 110 and bulk liquid electrolyte 140 do not mix together. For example, anode 110 can be a metal electrode, which can be a continuous solid. As another example, anode 110 can be a collection of particles, such as small or large particles, within a suspension that are not sufficiently buoyant to escape from the suspension into the electrolyte. As another example, anode 110 can be formed from particles that are not buoyant in the electrolyte.

[0046] Cathode electrode 120 (sometimes referred to as an air electrode) supports a reaction with oxygen at the positive electrode. Cathode 120 may be a so-called gas diffusion electrode (GDE), in which the cathode is a solid and is located at the interface between free space 105 for the gaseous phase and electrolyte 140. During the discharge process, cathode 120 supports the reduction of oxygen from free space 170 for the gaseous phase, the so-called oxygen reduction reaction (ORR). In certain embodiments, battery 100 is rechargeable, and a reverse reaction occurs in which cathode 120 supports the release of oxygen from the battery, the so-called oxygen evolution reaction (ORR). OER and ORR reactions are well known to those skilled in the art.

[0047] In certain embodiments, the cathode 120 is a single electrode that supports only ORR, and the battery is a primary (discharge-only) metal-air battery. In certain other embodiments, the cathode 120 is a single electrode that supports both ORR (discharge reaction) and OER (charge reaction), and the metal-air battery is rechargeable (secondary battery). The cathode 120 may be a single air electrode, a "bifunctional electrode," which operates in both OER and ORR modes, or may be a combination of two electrodes, a "dual electrode," in which one electrode is configured to operate in OER mode, and the other electrode is configured to operate in ORR mode.

[0048] In various embodiments, electrolyte 140 is a liquid. In particular embodiments, electrolyte 140 is an aqueous solution, a non-aqueous solution, or a combination thereof. In various embodiments, electrolyte 140 is an aqueous solution that can be acidic (low pH), neutral (intermediate pH), or basic (high pH; also referred to as alkaline or caustic). In particular embodiments, liquid electrolyte 140 comprises an electropositive element such as Li, K, Na, or combinations thereof. In some embodiments, the liquid electrolyte is basic, namely, with a pH greater than 7. In some embodiments, the pH of the electrolyte is greater than 10, and in other embodiments, greater than 12. For example, electrolyte 140 can comprise potassium hydroxide (KOH) with a concentration of 6 M (mol / liter).In certain embodiments of the invention, electrolyte 140 comprises a combination of components such as 5.5 M potassium hydroxide (KOH) and 0.5 M lithium hydroxide (LiOH). In certain embodiments, electrolyte 140 comprises sodium hydroxide (NaOH) at a concentration of 6 M (mol / liter). In certain embodiments, electrolyte 140 comprises sodium hydroxide (NaOH) at a concentration of 5 M (mol / liter) and potassium hydroxide (KOH) at a concentration of 1 M.

[0049] In certain embodiments, a battery 100 (e.g., a metal-air battery) is discharged by reducing oxygen (O2), typically from air. This requires three-phase contact between gaseous oxygen, an electronically active conductor that supplies electrons for the reduction reaction, and an electrolyte 140 that contains the product of the reduction step. For example, in certain embodiments including an aqueous alkaline electrolyte, oxygen from the air is reduced to hydroxyl ions via the half-reaction O2 + 2H2O + 4e - →4OH - .

[0050] Thus, supplying oxygen to metal-air cells requires gas manipulation and maintaining three-phase points. The three-phase point, or boundary, describes the region where contact occurs between the solid, electrolyte, and gas. This is where the heterogeneous reaction actually occurs. In specific embodiments, referred to as "normal air consumption" configurations, cathode 120 is mechanically positioned at the gas-liquid interface to stimulate and maintain three-phase boundaries. Cathode 120 can be positioned vertically or horizontally, or at any intermediate angle relative to the direction of gravity, and maintain a "normal air consumption" configuration. In these "normal air consumption" configurations, the gas phase is at atmospheric pressure (i.e., it is not subject to pressure other than that generated by gravity).

[0051] In various embodiments, a battery (e.g., battery 100) may include three electrodes: an anode (e.g., 110) and a dual cathode (e.g., cathode 120, consisting of two parts, such as a first cathode and a second cathode). The electrodes may have a finite useful life and may be mechanically replaceable. For example, the anode may be replaced depending on the season.

[0052] The first cathode may be configured to operate in an ORR mode, and may also be referred to as an "ORR electrode." The first cathode (i.e., the ORR electrode) may be divided into two portions, wherein the first portion has a hydrophilic surface and the second portion has a hydrophobic surface. For example, the hydrophobic surface may be a polytetrafluoroethylene (PTFE) (e.g., Teflon®) hydrophobic surface. For example, the second portion may be a microporous layer (MPS) of polytetrafluoroethylene (PTFE) and carbon with a high surface area, while the first portion may be carbon fiber partially coated with PTFE. As another example, the second portion may be an MPS of PTFE and carbon black, and the first portion may comprise approximately 33 wt.% PTFE. As a further example, the second portion may be an MPS comprising 23 wt.% PTFE and 77 wt.% carbon black, and the first part may be low loading MPS.

[0053] The second cathode may be configured to operate in OER mode and may also be referred to as the "OER electrode." The second cathode (i.e., the OER electrode) may have a hydrophilic surface. The second cathode may have a metal substrate, such as carbon (C), titanium (Ti), steel, etc., coated with nickel (Ni). An electrolyte (e.g., electrolyte 140) may be located between the three electrodes. The electrolyte may penetrate one or more of the three electrodes.

[0054] In certain embodiments, it may be advantageous to immerse the ORR electrode below the liquid level (e.g., the gas-liquid interface) of the cell. In these embodiments, which may be referred to as "air-reverse consumption" configurations, a three-phase interface is formed by supplying air (oxygen) to the ORR electrode, which is located below the liquid level. This provides several advantages. First, the ORR electrode is typically wetted, reducing the risk of drying out and the formation of a salt crust on the electrode. Second, leakage through the electrode can be purely internal to the cell and does not result in electrolyte leakage to the external environment. Third, the cell depth (the height of the main body) can be significantly greater.

[0055] FIG. 2 shows an example of an embodiment of a battery 200 having a submerged ORR electrode 203. The battery 200 includes a liquid electrolyte solution 140, at least one anode electrode 110 and at least one ORR electrode 203 located inside a primary housing 170. The battery 200 may also include at least one OER electrode 205 in the primary housing 170. Each of the electrodes 110, 203 and 205 may be partially or completely submerged below the liquid level 201 of the electrolyte solution 140. The outer portion of each of the submerged ORR electrodes 203 may be in contact with the electrolyte 140, which may partially penetrate into the ORR electrode 203. The interior of each of the ORR electrodes 203 may contain air (oxygen) and may be at least substantially free of electrolyte 140. Each of the ORR electrodes 203 may also include an active conductor (e.g., a current collector, not shown in FIG.2) to provide electrons for the reduction reaction. Thus, each of the 203 ORR electrodes can support multiple three-phase points or boundaries within the 203 ORR electrode.

[0056] Air can be supplied to the internal parts of each of the ORR electrodes 203 by one or more air lines 207. The air lines 207 can supply air from the free space 105 of the main body 170, from the external atmosphere and / or from a blower or similar mechanism that can actively supply air to the ORR electrodes 203. In some embodiments, the air supplied to the ORR electrodes 203 can be at a pressure greater than atmospheric. In some embodiments, air can circulate through each of the ORR electrodes 203 and can exit the corresponding ORR electrode 203 through a separate outlet air line or channel. Alternatively or additionally, air can be released from the ORR electrodes 203 into the liquid electrolyte 140.

[0057] Battery 200, as shown in FIG. 2, may have a repeating anode-cathode-anode-cathode arrangement configuration, wherein the number of repeating blocks, as well as the sizes, locations and orientations of the anode and cathode electrodes 110, 203 and / or 205 may vary in various embodiments of the invention.

[0058] FIG. 3A shows a side cross-sectional view of an example electrode assembly 300. During operation, the electrode assembly 300 can be partially or completely submerged below the electrolyte liquid level of a battery, such as battery 200 shown in FIG. 2. The electrode assembly 300 includes an electrode 203, such as an ORR electrode, which consists of a laminated sheet or film mounted on a support frame 305. The support frame 305 can include one or more open areas or channels 307 that can provide a flow field 309 for air or oxygen gas. One or more inlet channels (not shown in FIG. 3A) can supply gas (for example, air) to the flow field 309, where the gas can be directed toward and across the electrode 203. The support frame 305 may be made of plastic (e.g. polypropylene, HDPE, acrylonitrile butadiene styrene (ABS), etc.) and / or metal material (e.g. steel, nickel, etc.).The channels 307 of the flow field 309 may be configured to direct the gas flow through the flow field 309 and through the electrode 203. The channels 307 may have the form of a parallel, interdigitated, wavy or spiral geometric pattern. The support frame 305 may be sealed to prevent liquid electrolyte from entering the flow field 309 through the support frame 305. One or more outlet channels (not shown in FIG. 3A) may direct the gas flow from the flow field 309 to the outside of the electrode assembly 300.

[0059] The electrode 203 may include a layered structure that includes at least one first layer 311, which may also be referred to as an "active" layer and is located near the electrolyte, and at least one second layer 313, which may also be referred to as a "support" layer and is located near the flow field 309. The active layer 311 may include a hydrophilic surface, and the support layer 313 may include a hydrophobic surface. The support layer 313 may be a gas diffusion layer (GDL). A current collector may be integrated into the layered structure of the electrode 203. The electrode 203 shown in FIG. 3A may be referred to as a gas diffusion (GD) electrode 203.

[0060] FIG. 3B schematically shows a method for manufacturing a planar HD electrode 203 with a layered structure according to various embodiments. A plurality of individual sheets or films can be arranged to form a stack 320 of layers. The stack 320 of layers can include at least one active layer 311 and at least one support layer 313. Inside the stack 320, for example, between a pair of support layers 313, as shown in FIG. 3B, a current collector 315 can be arranged. Alternatively, the current collector 315 can be arranged between the active layer 311 and the support layer 313 or between two active layers 311. In various embodiments, the active layer 311 can be arranged on the outer surface of the stack 320 of layers.

[0061] In some embodiments, each of the active layers 311 and the support layers 313 may include a carbon-based material, and may also include additional materials such as binders and other functional additives such as PTFE. The current collector 315 may include an electrically conductive material, such as a metallic material. Suitable materials for the current collector 315 include nickel-plated carbon steel or copper. Other suitable conductive materials are within the intended scope of the invention. The current collector 315 may have a porous structure and may include, for example, a wire mesh, a metal foam, a porous sintered metal sheet, a metal fiber product, a perforated metal sheet, and the like.

[0062] As shown again in FIG. 3B, the stack of layers 320 can be subjected to mechanical pressure at an elevated temperature to adhere the individual layers together and form a layered structure of the HD electrode 203. In various embodiments, the HD electrode 203 with a layered structure can be formed using a hot pressing process. During the hot pressing process, the stack of layers 320 can be compressed under a pressure of at least about 400 psi while heating to a temperature of at least about 300 °C. The current collector 315 can be integrated into the HD electrode 203 with a layered structure. A portion of the current collector 315 may optionally extend beyond the edge of the layered structure to facilitate electrical contact with the current collector 315. On the outer surface of the HD electrode 203 with a layered structure, the active layer 311 can be exposed.

[0063] FIG. 3C is a perspective view of a GD electrode assembly 300 that includes a planar GD electrode 203 with a layered structure mounted on a support frame 305. The assembly 300 shown in FIG. 3C can be assembled by fixing the GD electrode 203 with a multilayer structure, as shown in FIG. 3B, in the support frame 305. The support frame may be made of a plastic material such as polypropylene, HDPE or ABS. The support frame 305 may include a flow field defined by one or more channels, as described above with reference to FIG. 3A. The flow of gas (e.g., air) into and out of the flow field may be provided by inlet and outlet channels 316 and 317. A sealing material 318 may be applied over portions of the assembly 300 to help seal the interior of the assembly 300 from penetration of liquid electrolyte.In some embodiments, the sealing material 308 may include a two-component epoxy resin that cures at an elevated temperature during a curing period. In some cases, the curing period may be 10 hours or more, for example, at least about 14 hours. After the curing process, at least a portion of the active layer 311 of the GD electrode 203 may be exposed on the outer surface of the GD electrode assembly 300. The support layer 313 of the GD electrode 203 may be pressed against the flux field. An electrical conductor 319 (for example, a wire) may be connected to the current collector 315 of the GD electrode 300.

[0064] Various embodiments of the present invention relate to electrodes, including electrodes 203 for an oxygen reduction reaction (ORR), electrode assemblies, and methods for manufacturing electrodes and electrode assemblies. An electrode assembly according to various embodiments may be a sealed gas diffusion electrode (GDE) assembly that may be partially or completely immersed in a liquid, such as a liquid electrolyte of a metal-air battery. In some embodiments, a double-sided sealed gas diffusion electrode (GDE) assembly includes active electrode layers on two opposite sides of the assembly. Various embodiments may provide an architecture and / or methods for sealing GDE assemblies. In various embodiments, GDE assemblies may be used in devices. In various embodiments, the devices may be primary or secondary batteries.In various embodiments, these devices may be suitable for energy storage. For example, the two-sided sealed GDE assemblies of various embodiments may form the cathode electrodes 120 (sometimes referred to as air electrodes) of a battery.

[0065] FIGS. 4A-4D are front, top, bottom and side views, respectively, of a sealed gas diffusion electrode (GDE) assembly 400 according to an embodiment of the present invention. The GDE assembly 400 according to various embodiments of the invention may be formed from two GD electrodes 203 with a layered structure, as described above, which have been bonded together to form a pouch- or pocket-like structure having an open internal chamber 401. In some embodiments, a continuous sheet or film structure containing a pair of GD electrodes 203 with a multilayer structure thereon may be assembled (e.g., folded in half) and sealed at its edges to form the GDE assembly 400 like a pouch or pocket. The GDE unit 400 may be immersed in the electrolyte bath of the metal-air battery such that the internal chamber 401 may be hydraulically isolated from the external electrolyte.Air may be present in the internal chamber 401 of the assembly 400 and react with the electrolyte, which controllably wets the outer surface of the electrode material. In various embodiments of the invention, the electrodes of the GDE assembly 400 support the oxygen reduction reaction (ORR) and may also be referred to as "ORR electrodes."

[0066] With reference to FIG. 4A-4D, the GDE assembly 400 may have a first side 403 and a second side 404 opposite the first side 403. For convenience, the first side 403 may be referred to as the "front" side 403, and the second side 404 may be referred to as the "back" side 403. The GDE assembly 400 may have a first peripheral edge 411, a second peripheral edge 406 opposite the first peripheral edge 411, a third peripheral edge 407, and a fourth peripheral edge 408 opposite the third peripheral edge 407. For convenience, the first peripheral edge 411 may be referred to as the "upper" peripheral edge of the GDE assembly 400, the second peripheral edge 406 may be referred to as the "lower" peripheral edge of the GDE assembly 400, and the third and fourth peripheral edges 407 and 408 may be referred to as the "lateral" peripheral edges of the 400 GDE unit.

[0067] As shown in FIG. 4A-4D, the HDE assembly 400 may have a substantially planar flat portion 405 having a shape resembling the letter "U" and extending continuously near the side peripheral edges 407 and 408 and the lower peripheral edge 406 of the HDE assembly 400. The front side 403 and the rear side 404 of the HDE assembly 400 may also include convex portions 409 that are inclined or curved outward from the flat portion 405 and extend from the flat portion 405 to the central region 410 of the HDE assembly 400. In some embodiments, the central region 410 of the GDE assembly 400 may include substantially planar flat surfaces on the front side 403 and the rear side 404, which are raised relative to the substantially planar flat section 405 extending along the periphery of the GDE assembly 400. The raised central region 410 on the front 403 and rear 404 sides of the GDE assembly 400 may extend to the upper peripheral edge 411 of the GDE assembly 400.The upper peripheral edge 411 of the GDE assembly 400 may form an opening in the internal chamber 401 of the GDE assembly 400. In embodiments in which the GDE assembly 400 is made of a pair of GD electrodes 203a, 203b with a layered structure, the corresponding GD electrodes 203a, 203b may be in contact with each other along a substantially planar flat section 405 that extends along the periphery of the GDE assembly 400. The corresponding GD electrodes 203a and 203b with a layered structure may be linked together along the flat planar section 405 to form a liquid-tight sealed connection. In some embodiments, described in more detail below, a sealing material may be located between the pair of GD electrodes 203a and 203b with a layered structure along the substantially planar flat portion 405 and / or along the side peripheral edges 407 and 408 and the lower peripheral edge 406 of the GD assembly 400.Each of the outer surfaces of the GDE assembly 400 on the front 403 and rear 404 sides may include an active electrode layer, as described above. The active electrode layers may include a hydrophilic surface. The inner surfaces of the GDE assembly 400, which encompass the inner chamber 401 and form its outer surfaces, may include a support layer, as described above. Each of the support layers may include a hydrophobic surface. Current collectors may be embedded between the active electrode layers on the outer surfaces of the GDE assembly and the support layers that form the surfaces of the inner chamber 401 of the GDE assembly 400. Thus, the GDE assembly 400 may include a pair of functional electrodes, such as GD electrodes with a layered structure, on two opposite sides 403, 404 (i.e., surfaces) of the GDE assembly 400, and may be referred to as a “double-sided” sealed GDE assembly 400.

[0068] The double-sided sealed GDE assembly 400, such as shown in FIGS. 4A-4D, can be advantageous in terms of manufacturability and cost effectiveness. In various embodiments, discussed in more detail below, the double-sided sealed GDE assembly 400 can be manufactured using several simple steps, including, in some cases, a single-step process that includes forming one or more electrodes by laminating a multilayer stack while simultaneously forming a sealed body of the GDE assembly 400. This avoids the complex processes used to manufacture the electrode assembly 300, such as shown in FIG. 3C, which often requires complex fixtures, skilled operators, and long curing times to manufacture and properly seal the assembly 300.

[0069] FIG. 5A is a perspective view of a mold 500 that can be used to manufacture a layered GD electrode 203 having a desired three-dimensional shape. The mold 500 can be used to form the HD electrode 203 with a layered structure, having a three-dimensional shape with a flat flange-shaped part passing around the HD electrode 203 and adjacent to the lower peripheral edge and the lateral peripheral edges of the electrode, and a convex part that passes between the flange-shaped part and a raised part located in the central region and passing to the upper peripheral edge of the HD electrode 203. In various embodiments of the invention, a pair of HD electrodes 203 having such a three-dimensional shape can be connected together and hermetically connected along the corresponding flange-shaped parts to obtain an assembly 400 of a double-sided hermetic HDE, as shown in FIGS. 4A-4D.

[0070] FIG. 5B and 5C schematically show a method for manufacturing a double-sided sealed GDE assembly 400 using a "two-step" lamination and sealing process. Referring to FIG. 5B, in the first step of the two-step lamination and sealing process, a stack of 320 layers, such as the stack of 320 layers described above with reference to FIG. 3B, can be placed in the mold cavity 500. In various embodiments, the stack of layers 320 may include at least one active electrode layer 311 and at least one support layer 313. The stack of layers 320 may also include a current collector 315. The mold 500 may include a two-piece structure comprising a first piece 500a having a convex cross-sectional shape and a second piece 500b having a complementary concave cross-sectional shape.The stack 320 of layers can be placed in the mold 500 in such a way that the active layer 311 of the electrode is located on the outer surface of the stack 320 of layers facing the second part 500b, and the support layer 313 is located on the outer surface of the stack 320 of layers facing the first part 500a.

[0071] After this, the stack of layers 320 can be mechanically pressed between the first part 500a and the second part 500b of the mold 500, as schematically illustrated by arrows 503 in FIG. 5B. In some embodiments, the stack of layers 320 can be pressed using a hot pressing process. During the hot pressing process, the stack of layers 320 can be heated to an elevated temperature by a heat source 501, which can be, for example, an inductive heat source, an indirect resistive heating source and / or a direct resistive heating source. In some embodiments, during the hot pressing process, the stack of layers 320 can be compressed under a pressure of at least about 400 psi while heating to a temperature of at least about 300°C. By the hot pressing process, the 203 ORR electrode can be obtained with a layered structure having the desired three-dimensional shape, as noted above.To obtain a plurality of HD electrodes 203 with a layered structure, a plurality of stacks 320 of layers can be pressed in a mold 500, as shown in FIG. 5B. Each HD electrode 203 with a layered structure can have an identical or substantially identical three-dimensional shape.

[0072] Referring to FIG. 5C, in the second step of the two-step lamination and sealing process, a pair of HD electrodes 203a and 203b with a layered structure can be placed in a mechanical pressing device 505. Each of the HD electrodes 203a and 203b with a layered structure can have an identical or substantially identical three-dimensional shape and can be formed using the method described above in FIG. 5B. The HD electrodes 203a and 203b with a layered structure can be placed in a mechanical pressing device 505 in such a way that the flat, flange-shaped parts passing along the periphery of the HD electrodes 203a and 203b near the lower and lateral peripheral edges of the HD electrodes 203a and 203b come into contact with each other.The convex portions of the GD electrodes 203a and 203b extending from the corresponding flat flange-shaped portions of the GD electrodes 203a and 203b may be directed away from each other to provide an empty area 506 between the corresponding GD electrodes 203a and 203b inside the mechanical pressing device 505.

[0073] Then, the pair of GD electrodes 203a and 203b can be mechanically pressed together between a pair of heated pressing plates 505a and 505b of the mechanical pressing device 500, as schematically illustrated by arrows 503 in FIG. 5C. The heated pressing plates 505a and 505b can mechanically press the GD electrodes 203a and 203b along flat flange-shaped portions extending along the periphery of the GD electrodes 203a and 203b to bind the GD electrodes 203a, 203b together and provide a continuous seal around the bottom and sides of the GD electrodes 203a and 203b. During the pressing process, the pressing plates 505a and 505b may be heated by a heat source 509. In some embodiments, the pressing plates 505a and 505b may apply a pressure of at least about 400 psi while heating the GD electrodes 203a and 203b to a temperature of at least about 300°C.During the pressing process, a double-sided sealed GDE unit 400 can be obtained, containing an internal chamber 401, as shown in FIG. 4A 4D.

[0074] In some embodiments, the double-sided sealed GDE assembly 400 may be manufactured using a "three-step" process that includes an initial lamination step to form GD electrodes 203a and 203b, for example, by a hot pressing process, as shown in FIG. 5B, followed by an initial bonding step to glue the pair of GD electrodes 203a and 203b together in the form of the final GDE assembly 400 and then a high-temperature mechanical pressing step, as shown in FIG. 7C, to form a permanent bond and provide a continuous seal around the bottom and sides of the GD electrodes 203a and 203b. In some embodiments, the initial bonding step may include a bonding step at a relatively low pressure and / or low temperature.

[0075] FIG. 5D schematically shows an alternative two-step lamination and sealing process according to an embodiment of the present invention. Referring to FIG. 5D, before the mechanical pressing step, a sealing material 510 can be placed between the HD electrodes 203a and 203b. The sealing material 510 can be placed between the HD electrodes 203a and 203b along flat flange-shaped portions extending along the periphery of the HD electrodes 203a and 203b. The sealing material 510 can include, for example, fluorinated ethylene propylene (FEP), polytetrafluoroethylene (PTFE) or another thermoplastic material, an epoxy material and / or a hot-melt adhesive material such as ethylene vinyl acetate. Other suitable sealing materials are within the intended scope of the invention.The sealing material 510 may function similarly to a "sealing gasket" in the final pressed product and may improve the sealing of the double-sided sealed GDE assembly 400 to help minimize or prevent liquid penetration into the internal chamber 401 when the GDE assembly 400 is immersed in an electrolyte. In some embodiments, the sealing material 510 may be electrically insulating to provide electrical insulation between the respective electrodes 203a and 203b of the double-sided sealed GDE assembly 400.

[0076] Alternatively or additionally, an external seal may be provided over the outer surface of the GDE assembly 400. FIG. 6 shows the GDE assembly 400, which includes a sealing material 600 located around the lower peripheral edge 406 and the side peripheral edges 407 and 408 of the GDE assembly 400. For example, the sealing material 600 may include epoxy paint, epoxy dispensed material, or epoxy impregnation, which may be located along the edges of the GDE assembly 400 to provide additional sealing integrity. In some embodiments, the sealing material 600 may include a mechanical seal, such as one or more clips, clamps, or tape, which may be located around the outer edges of the GDE assembly 400.In some embodiments, the sealing material 600 may include an epoxy-coated tape that is adhered to the edges of the GDE assembly 400 to "dose" the edge seal with additional epoxy resin to improve the integrity of the seal.

[0077] In some embodiments, the hydrostatic pressure of the liquid electrolyte when the GDE assembly 400 is immersed in the electrolyte may be sufficient to "clamp" the GD electrodes 203a, 203b with a layered structure together to ensure proper hydraulic isolation of the internal chamber 401 of the GDE assembly 400 from the surrounding liquid electrolyte.

[0078] FIG. 7 schematically shows a method for manufacturing a double-sided sealed GDE assembly 400 using a "one-step" lamination and sealing process. Referring to FIG. 7, a pair of layer stacks 320a and 320b can be placed in a mold cavity 700. In various embodiments, each of the layer stacks 320a and 320b can include at least one active electrode layer 311 and at least one support layer 313, as shown in FIG. 3B. Each of the stacks 320a and 320b of layers may also include a current collector 315. The mold 700 may include a three-piece structure including a first piece 700a having a concave cross-sectional shape and a second piece 700b also having a concave cross-sectional shape.The concave cross-sectional shapes of the first part 700a and the second part 700b may be identical or substantially identical to each other, and the concave surfaces of the first and second parts 700a and 700b may be arranged in the mold 700 in such a way that they face each other, as shown in FIG. 7. The mold 700 in the embodiment of FIG. 7 may also include a third part 700c located between the first part 700a and the second part 700b. The third part 700a may include a convex cross-sectional shape that includes a first convex surface 702 complementary to and facing the concave surface of the first part 700a of the mold 700, and a second convex surface 704 complementary to and facing the concave surface of the second part 700b of the mold 700.

[0079] In the mold 700, a first stack of layers 320a may be placed between the first part 700a and the third part 700a, and a second stack of layers 320b may be placed between the second part 700b and the third part 700c of the mold 700, as shown in FIG. 7. Portions of the stacks 320a and 320b of layers along the bottom side and two lateral sides of the corresponding stacks 320a and 320b of layers may extend beyond the peripheral edges of the third part 700c of the mold 700. The first stack 320a and the second stack 320b of layers may be arranged in such a way that the support layer 313 on the outer surface of the corresponding stacks 320a and 320b of layers faces the third part 700c, and the active layer 311 located on the outer surface of the corresponding stacks 320a and 320b of layers faces either the first part 700a or the second part 700b of the mold 700.

[0080] Then the first stack 320a of layers can be mechanically pressed between the first part 700a and the surface 702 of the third part 700c of the mold 700, while at the same time the second stack 320b of layers can be mechanically pressed between the second part 700b and the surface 704 of the third part 700c of the mold 700, as schematically shown by arrows 503 in FIG. 7. The peripheral portions of the first stack 320a of layers and the second stack 320b of layers along the bottom side and two lateral sides of the stacks 320a and 320b of layers may be in contact with each other and may be mechanically pressed between the first part 700a and the second part 700b of the mold 700 to form a substantially planar flat section 405 of the finished GDE assembly 400 (see FIGS. 4A-4D). In some embodiments, the first stack 320a of layers and the second stack 320b of layers may be pressed using a hot pressing process.During the hot pressing process, the stacks of layers 320a and 320b may be heated to an elevated temperature by a heat source 701, which may be, for example, an inductive heat source, an indirect resistive heating source, and / or a direct resistive heating source. In some embodiments, during the hot pressing process, the stacks of layers 320a and 320b may be compressed under a pressure of at least about 400 psi while heating to a temperature of at least about 300°C. The hot pressing process allows each of the stacks 320a and 320b of layers to be laminated to obtain a pair of GD electrodes 203a and 203b with a layered structure having a desired three-dimensional shape, while simultaneously bonding the pair of GD electrodes 203a and 203b with a layered structure together and providing a continuous seal around the bottom and sides of the GD electrodes 203a and 203b.Accordingly, the double-sided sealed GDE assembly 400 can be manufactured using a single, one-step lamination and sealing process. The double-sided sealed GDE assembly 400 can be removed from the mold 700, as shown on the right in FIG. 7.

[0081] FIG. 8 schematically shows a method for manufacturing a GDE assembly 400 using an alternative "one-step" lamination and sealing process according to an embodiment of the present invention. Referring to FIG. 8, before lamination and sealing using a mold 700, a sealing material 510 can be placed between the first stack of layers 320a and the second stack of layers 320b. The sealing material 510 can be placed between the stacks of layers 320a and 320b, wherein the stacks of layers 320a and 320b contact each other near the lower and lateral peripheral edges of the stacks of layers 320a and 320b. The sealing material 510 can include any suitable sealing material, such as the sealing materials described above with reference to FIG. 5D.The sealing material 510 can improve the sealing of the double-sided sealed GDE assembly 400 to help minimize or prevent liquid penetration into the internal chamber 401 when the GDE assembly 400 is immersed in an electrolyte. In some embodiments, the sealing material 510 can be electrically insulating to provide electrical insulation between the respective electrodes 203a and 203b of the double-sided sealed GDE assembly 400. Alternatively or additionally, after the lamination and sealing step in the mold 700, an external seal can be formed over the outer surface of the GDE assembly 400 along the edges between the electrodes 203a and 203b, as described above with reference to FIG. 6.

[0082] FIG. 9 is a side view of a mold 700, such as shown in FIGS. 7 and 8, taken along line A-A' in FIG. 8. FIG. 9 shows an alternative one-step lamination and sealing process according to an embodiment of the present invention. In the alternative one-step lamination and sealing process shown in FIG. 9, one continuous stack 320 of layers can be placed in the mold. One continuous stack 320 of layers can be folded in such a way that the first part of the continuous stack 320 of layers can be located between the first part 700a and the third part 700c of the mold 700, and the second part of the continuous stack 320 of layers can be located between the second part 700b and the third part 700c of the mold 700, as shown in FIG. 9. The parts of the continuous stack 320 of layers adjacent to the side edges of the continuous stack 320 of layers can extend beyond the peripheral edges of the third part 700c of the mold 700.A portion of the continuous stack 320 of layers comprising a fold 901 in the continuous stack 320 of layers may also extend beyond the peripheral edge of the third part 700c of the mold 700, as shown in FIG. 9. The continuous stack 320 of layers may be mechanically pressed and subjected to elevated temperature to laminate and seal one continuous stack 320 of layers and obtain an assembly 400 of a two-sided sealed GDE in one step, as described above with reference to FIG. 7. In some embodiments, the pressing process may provide a pair of seals extending along the sides of the GDE assembly 400, but may not seal the assembly 400 along the bottom side of the assembly 400. In such embodiments, the fold 901 in the continuous stack 320 of layers may provide sufficient hydraulic insulation along the lower peripheral edge 406 of the GDE assembly 400.

[0083] Although the embodiment of the invention shown and described with reference to FIG. 9 includes a "one-step" lamination and sealing assembly process, it should be understood that a similar method can be used to form the GDE assembly 400 from the single-layer stack 320 using a "two-step" lamination and sealing assembly process. In particular, in the initial step, the stack 320 of layers can be pressed (for example, by hot pressing), as described above, to obtain a layered structure having the desired three-dimensional shape, as described above with reference to FIG. 5B. For example, the initial lamination step can provide a pair of GD electrodes 203 with a layered structure, located back to back on one layered sheet. The layered sheet can be folded in a clamshell configuration and placed in a mold 700, as shown in FIG. 9, or, alternatively, into a mechanical pressing device 505, such as shown in FIG.5C and 5D. To seal the continuous layered structure and produce the 400 double-sided sealed GDE assembly, a second stage of mechanical pressing at elevated temperature can be used.

[0084] FIG. 10 schematically shows an alternative one-step lamination and sealing process that can be used to produce a plurality of HDE assemblies 400 simultaneously according to another embodiment of the present invention. FIG. 10 shows a device 1000 that includes a pair of molds 903a and 903b located next to each other. Each of the molds 903a and 903b may include a three-piece structure including a first piece 700a, a second piece 700b, and a third piece 700c between the first piece 700a and the second piece 700b, as noted above with reference to FIG. 7. The first continuous stack 320a of layers can be fed into the device 1000 in such a way that the first continuous stack 320a of layers passes between the first part 700a and the third part 700c in the first mold 903a and between the first part 700a and the third part 700c in the second mold 903b.The second continuous stack 320b of layers can be fed into the device 1000 in such a way that the second continuous stack 320a of layers passes between the second part 700b and the third part 700c in the first mold 903a and between the second part 700b and the third part 700c in the second mold 903b. In some embodiments, one or more feeding devices, such as rollers (not shown in FIG. 10), can be used to feed the respective stacks 320a and 320b of layers into the device 1000. The device 1000 may mechanically press the stacks 320a and 320b of layers inside the molds 903a and 903b, while the stacks 320a and 320b of layers are heated using the heat source 701 to laminate and seal the stacks 320a and 320b of layers and obtain a pair of assemblies 400 of double-sided sealed GDEs.In some embodiments, to separate the two GDE assemblies 400 that are produced during the pressing step, the stacks 320a and 320b of layers may be cut by a cutting device 904 during the pressing process.

[0085] Although the embodiment shown in FIG. 10 illustrates two continuous stacks 320A and 320B of layers in the device 1000, it should be understood that in some embodiments, a single-layer stack 320 can be fed into the device 1000 so that the stack 320 of layers is folded over the upper and lower surfaces of the third parts 700c of the corresponding molds 903a and 903b, as shown in FIG. 9. Thus, a single-layer stack 320 can be used to obtain a pair of GDE assemblies 400 in a one-step lamination and sealing process.

[0086] Furthermore, although the embodiment shown and described with reference to FIG. 10 includes a "one-step" lamination and sealing assembly process, it is understood that a similar process can be used to form a plurality of GDE assemblies 400 using a "two-step" lamination and sealing assembly process. In particular, in an initial step, a pair of continuous stacks 320a and 320b of layers can be pressed (for example, hot pressed) to obtain a pair of GD electrodes 203 with a layered structure on a single layered sheet. The layered sheet can be located in a device 1000 containing two pressing molds 903a and 903b, for example, shown in FIG. 10, or, alternatively, in a device containing a pair of mechanical pressing devices 505, for example, shown in FIG. 5C and 5D.To seal the continuous layered structures and produce a pair of assemblies 400 of the double-sided sealed GDE, a second stage of mechanical pressing at elevated temperature can be used. The individual GDE assemblies 400 can be separated from each other by a cutting device 904, shown in FIG. 10.

[0087] Furthermore, although the embodiment of the invention shown in FIG. 10 illustrates a molding device 1000 that includes a pair of molds 903a and 903b located next to each other, it should be understood that the molding device 1000 may contain more than two molds 903 or pressing devices 505 and may be configured to produce more than two HDE assemblies 400 simultaneously. The molding device 1000 may include a line of molds 903 / pressing devices 505 located along one direction, or may include a two-dimensional array of molds 903 / pressing devices 505 extending along two perpendicular directions.

[0088] In some embodiments, the double-sided sealed GDE assembly 400 obtained using a "one-step" or "two-step" lamination and sealing process may include at least one outer surface having a textured, contoured and / or rough three-dimensional shape. In particular, the central region(s) 410 of the front 403 and / or rear 404 sides of the GDE assembly 400 (see FIGS. 4A-4D) may include a textured, contoured and / or rough surface, rather than a substantially planar surface as shown in FIGS. 4A-4D. The textured, contoured and / or rough surface may increase the surface area of ​​the GDE assembly 400, which may increase the area and / or number of three-phase boundaries. In FIG. 11A-11C are sectional views of exemplary GDE assemblies 400 having contoured outer surfaces. In particular, the front side 403 and the rear side 404 of the GDE assemblies of FIG.11A-11C comprise a ribbed configuration including sawtooth ribs 1101 (FIG. 11A), sinusoidal ribs 1102 (FIG. 11B) and square-wave ribs 1103 (FIG. 11C). Other suitable three-dimensional contours, textures and / or patterns may also be used. Textured, contoured and / or rough shapes may be formed during the lamination process used to obtain the HD electrodes 203a and 203b with a layered structure. For example, a mold 500, 700, 903a, 903b, such as shown in FIG. 5A-5B and 7-10, may be shaped to impart a textured, contoured, and / or roughened three-dimensional shape to the stacks of 320 layers during the "one-step," "two-step," or "three-step" lamination and sealing process as described above.

[0089] FIGS. 12A-12C show a GDE assembly 400 and a process for producing the GDE assembly 400 having a reduced active area, according to an embodiment of the present invention. In some cases, it may be advantageous to limit the size of the active layer materials of the electrode used in the GD electrode 203 with a layered structure and / or the GDE assembly 400. For example, limiting the area of ​​the active layer 311 to only the electrochemically active regions of the electrode 203 and / or the GDE assembly 400 (i.e., regions in which a gas-liquid interface may occur) can help reduce the cost of the electrode / GDE assembly. FIG. 12A shows a top view of a stack of layers 320, which includes at least one active layer 311, at least one support layer 313 and an optional current collector 315.In one non-limiting embodiment, the stack of layers 320 may include an active layer 311 located above or below a pair of support layers 313 with a current collector 315 located between the pair of support layers 313. The current collector 315 may partially extend beyond the periphery of the active layer 311 and the support layers 313 at the first end 1201 of the stack 320. The length and / or width dimension of the active layer 311 may be smaller than the corresponding length and / or width dimension of at least one support layer 313, such that the surface of the support layer 313 may be exposed adjacent to the active layer 311 in the gap region 1205 along the periphery of the stack of layers 320. In the embodiment of the invention shown in FIG. 12A, the gap region 1205 extends continuously along the side edges 1203 and 1204 and the bottom edge 1202 of the stack of layers.

[0090] FIG. 12B and 12C are front and side views of the GDE assembly 400, which can be formed using the stack of layers 320 as shown in FIG. 12A. The GDE assembly 400 can be formed using any of the methods described above, such as a "one-step" or "two-step" lamination and sealing method using mechanical pressure and heat. Thus, the stack of layers 320 shown in FIG. 12A can form a GD electrode 203a with a layered structure, which can be located on one side (i.e., on the surface) 403 of the double-sided sealed GDE assembly 400. The second GD electrode 203b with a layered structure can form the opposite side (i.e., surface) 404 of the double-sided sealed GDE assembly 400. As shown in FIG. 12B and 12C, the active layer 311 of the electrode 203a is located above the central region 410 and extends to the upper peripheral edge 411 of the GDE assembly 400, and can also extend above the convex portions 409 of the GDE assembly 400.In this embodiment, the active layer 311 does not reach the lower peripheral edge 406 or the lateral peripheral edges 407 and 408 of the GDE assembly 400. In some embodiments, the active layer 311 may be absent from the substantially planar flat section 405 of the GDE assembly 400. In other embodiments, the active layer 311 may extend over a portion of the planar flat section 405, but may not reach the lower peripheral edge 406 and / or the lateral peripheral edges 407 and 408 of the GDE assembly 400. In some embodiments, the support layer 313 may be exposed on the planar flat section 405 of the GDE assembly 400.

[0091] FIGS. 13A-13C show a GDE assembly 400 and a process for producing the GDE assembly 400 having a reduced active area according to another embodiment of the present invention. The embodiment of FIGS. 13A-13C is similar to the embodiment of FIGS. 12A-12C except that the active layer 311 does not extend to the upper peripheral edge 411 of the GDE assembly 400. In many cases, when the GDE assembly 400 is immersed in a liquid electrolyte bath, the electrolyte liquid level may not reach the uppermost portions of the GDE assembly 400. In addition, the location of the liquid level may change over time, which may be due to cycling during battery operation. This is illustrated in FIG. 13B, which schematically shows a range 1302 of liquid level locations during normal battery operation.Since the upper portion of the GDE assembly 400 is not constantly wetted by the electrolyte, cost savings can be achieved by using a reduced active area when the active layer 311 does not extend to the upper peripheral edge 411 of the GDE assembly 400. However, leaving the support layer 313 exposed in this area may be undesirable, since the change in the electrolyte liquid level means that the support layer 313 will often be directly exposed to the liquid electrolyte. To solve this problem, a strip of inactive sealing material 1300 can be provided on the outer surface of the electrodes 203a, 203b on or near the upper peripheral edge 411 of the GDE assembly 400. FIG. 13A shows a top view of a stack of layers 320 that includes at least one active layer 311, at least one support layer 313 and a current collector 315.The active layer 311 does not reach the upper peripheral edge 1201 of the stack of layers 320, so that between the periphery of the active layer 311 and the upper peripheral edge 1201 of the stack of layers 320 there is a gap region 1301. On the stack of layers 320, a strip of inactive sealing material 1300 may be provided over the entire gap region 1301 or a part thereof. The inactive sealing material 1300 may extend between the lateral peripheral edges 1203 and 1204 of the stack of layers 320, and in some embodiments may extend to the upper peripheral edge 1201 of the stack of layers 320. In other embodiments, for example, as shown in FIG. 13A, the inactive sealing material 1300 may not reach the upper peripheral edge 1201 of the stack of layers 320, so that near the upper peripheral edge 1201 of the stack of layers 320, the region of the support layer 313 may be exposed.The inactive sealing material 1300 may be comprised of a suitable material that is not electrochemically active in the final GDE electrode / assembly and prevents or inhibits the permeation of liquid electrolyte through the sealing material 1300 and into the GDE assembly. In some embodiments, the inactive sealing material 1300 may be a plastic sheet or membrane.

[0092] FIG. 13B and 13C show front and side views of the GDE assembly 400, which can be formed using a stack of 320 layers, as shown in FIG. 13A. The GDE assembly 400 can be formed using any of the methods described above, such as a "one-step" or "two-step" lamination and sealing method using mechanical pressure and heat. Each of the GD electrodes 203a and 203b with a layered structure that make up the GDE assembly 400 can include a strip of inactive sealing material 1300 passing through the upper region of the electrodes 203a and 203b. The active layers 311 of the electrodes 203a and 203b may be arranged vertically below and adjacent to the strips of inactive sealing material 1300. The strips of inactive sealing material 1300 may at least partially overlap the range 1302 of liquid level locations during normal operation of the battery.In various embodiments, the upper edges of the strips of inactive sealing material 1300 may be located above the upper limit of the range 1302 of liquid level locations. In some embodiments, the strips 1300 may extend to the upper peripheral edge 411 of the HDE assembly 400. In other embodiments, such as those shown in FIGS. 13B and 13C, the upper edges of the strips 1300 may be located below the upper peripheral edge 411 of the HDE assembly 400. Between the upper edges of the strips 1300 and the upper peripheral edge 411 of the HDE assembly 400, the support layer 313 may be exposed. In some embodiments, the lower limit of the range 1302 of liquid level locations is below the lower edges of the strips 1300 and may correspond to the locations of the active layers 311.

[0093] FIG. 14A and 14B are top and side views, respectively, of the GDE assembly 1400 according to another embodiment of the present invention. Referring to FIG. 14A and 14B, the GDE assembly 1400 includes a GD electrode 203 with a layered structure on a first (e.g., front) side 403 of the GDE assembly 1400. The opposite (for example, rear) side 404 of the GD-electrode 1400 comprises a planar surface 1401. The GD-electrode 203 with a layered structure may have a contoured three-dimensional shape, including a flat planar section 405 adjacent to the lower peripheral edge 406 and the lateral peripheral edges 407, 408 of the GD-electrode 203 with a layered structure, and a convex section 409 extending from the flat planar section 405 to the raised central region of the GD-electrode 203 with a layered structure.The GD electrode 203 with a layered structure can be connected to the second element 1402, which can be a substantially flat sheet or substrate forming a planar surface 1401 on the back side 404 of the GDE assembly 1400. The GDE assembly 1400 can include an opening near the upper peripheral edge 411 of the GDE assembly 1400, passing into the internal chamber 401 located between the GD electrode 203 and the second element 1402. The GDE assembly 1400 can be sealed for hydraulic isolation of the internal chamber 401 from the surrounding liquid electrolyte. The GDE assembly 1400 may be sealed using any of the methods described above, such as by hot pressing the GD electrode 203 with a layered structure and the second element 1402 around the flat planar section 405 of the GD electrode 203 (with or without a sealing material) to form a continuous seal along the side and bottom sides of the assembly 1400.Alternatively or additionally, an outer seal may be used to seal the edges of the assembly 1400 between the GD electrode 203 and the second element 1402.

[0094] In some embodiments, the second element 1402 may be electrochemically inert. For example, the second element 1402 may be a support substrate that may be made of plastic or another suitable material. In embodiments in which the second element 1402 is electrochemically inert, the GDE assembly 1400 includes an electrode 203 on the first (e.g., front) side 403 of the GDE assembly 1400, but does not include an electrode on the opposite (e.g., back) side 404 of the GDE assembly 1400. Thus, the GDE assembly 1400 may be referred to as a "single-sided GDE assembly 1400."

[0095] Alternatively, the second element 1402 may be electrochemically active and may include a planar electrode on the second (e.g., rear) side 404 of the GDE assembly 1400. The planar electrode may be, for example, an ORR electrode or an OER electrode.

[0096] The GD electrode 203 with a layered structure can be formed using any of the methods described above. For example, a two-step process can be used to form the GD electrode 203, including pressing a stack of layers in a mold at an elevated temperature to form the GD electrode 203 of the desired three-dimensional shape, followed by a second step of bonding and hermetically sealing the GD electrode 203 with the second element 1402, for example, using a heated mechanical press. Alternatively, the GDE assembly 1400 can be obtained in a one-step process, which can include molding the GD electrode 203 with a layered structure in a mold while simultaneously hermetically connecting the GD electrode 203 with the second element 1402.

[0097] FIG. 15A and 15B show front and top views, respectively, of the double-sided sealed GDE assembly 400, which includes an insert 1500 in the inner chamber 401 of the GDE assembly 400. The insert 1500 may include open areas or channels that form a flow field, for example, described above with reference to FIG. 3A. The insert 1500 may form a pair of flow fields configured to direct air through the rear sides of the corresponding GD electrodes 203a and 203b. The insert 1500 may consist of a suitable material, such as a plastic and / or metal material. In some embodiments, the insert 1500 may be inserted into the inner chamber 401 of the GDE assembly 400 in such a way that the flow fields can adjoin the adjacent electrodes 203a and 203b. In some embodiments, an adhesive material may be used to bond the insert 1500 to adjacent surfaces of the electrode.Optionally, a filler may be provided around the periphery of the insert 1500 to fill the remaining volume of the chamber 401, for example, in non-electrochemically active regions of the GDE assembly 400. Since the insert 1500 is located within the sealed internal chamber 401 of the GDE assembly 400, the insert 1500 is not exposed to the potentially corrosive liquid electrolyte. Therefore, less resistant and / or less expensive materials may be used. Furthermore, since the insert 1500 is not directly exposed to the electrolyte, the structure of the insert 1500 does not necessarily have to be impermeable to liquid. Air may be directed to and from the insert 1500 through one or more channels 1503 and 1503.

[0098] In some embodiments, the insert 1500 may consist of an electrically conductive material or include an electrically conductive material (e.g., a metallic material) that may be in contact with the electrodes 203a and 203b. In such embodiments of the invention, the insert 1500 may be used as an alternative to or in addition to an electrically conductive current collector embedded in the layered GD electrodes 203a and 203b.

[0099] FIGS. 16A-16C show a method for manufacturing a double-sided sealed GDE assembly 400 containing an internal conductive element 1603 according to another embodiment of the present invention. FIG. 16A shows a stack of layers 320 containing an active layer 311, a pair of support layers 313 and a current collector 315 between the pair of support layers 313. As shown in FIG. 16B, heat and pressure (indicated by arrows in FIG. 16A) can be applied to the stack of layers 320 to obtain a GD electrode 203a with a layered structure. A portion of the current collector 315 and at least one support layer 313 at the edge 1601 of the stack of layers 320 can remain unlaminated, as shown in FIGS. 16A and 16B. The unlaminated portion of the current collector 315 may be attached to the conductive element 1603, as shown in FIG. 16B. In some embodiments, the conductive element 1603 may be a busbar. The current collector 315 may be attached to the conductive element / busbar 1603 using any suitablemethod, for example, by a separate lamination process.

[00100] With reference to FIGS. 16B and 16C, the unlaminated portion of the current collector 315 and the conductive element / busbar 1603 may be bent or folded such that the conductive element / busbar 1603 is located above the surface of the HD electrode 203a with a layered structure. The conductive element / busbar 1603 may be attached to the unlaminated portion of the current collector 315 of the second HD electrode 203b with a layered structure, as shown in FIG. 16C. The non-laminated portions of the support layers 313 of the first GD electrode 203a with a layered structure and the second GD electrode 203b with a layered structure may be bonded together to form a double-sided sealed GD assembly 400 having a seal 1605 extending along the periphery of the assembly 400, as shown in FIG. 16C. The conductive element / bus 1603 may be located on the same side of the seal 1605 as the internal chamber 401 of the GD assembly 400 and, thus, may not be exposed to liquidelectrolyte when the GDE assembly 400 is immersed in the electrolyte bath. This may eliminate the need to protect the conductive element / busbar 1603 below the electrolyte liquid level. In some embodiments, the conductive element / busbar 1603 may extend in the vertical direction (inside and out of the page in FIGS. 16A-16C) when the GDE assembly 400 is immersed in the electrolyte.

[00101] FIGS. 17A and 17B show a method of manufacturing a double-sided sealed GDE assembly 1700 comprising a pair of planar GD electrodes 1701a and 1701b attached to a support frame 1703. In FIG. 17A is a sectional view of a pair of planar GD electrodes 1701a and 1701b and a support frame 1703 in a mechanical pressing device 1705 during the process of manufacturing a double-sided sealed GD assembly 1700. FIG. 17B is a perspective view of a completed double-sided sealed GD assembly 1700. As shown in FIG. 17A, each of the GD electrodes 1701a and 1701b may be GD electrodes with a layered structure, which maybe formed by mechanical pressing at elevated temperature (for example, hot pressing) of a stack of layers comprising at least one active layer and at least one support layer, as described above. The HD electrodes 1701a and 1701b with a layered structure may also include an integrated current collector. The HD electrodes 1701a and 1701b with a layered structure may have planar outer surfaces, as shown in FIGS. 17A and 17B. Alternatively, the HD electrodes 1701a and / or 1701b with a layered structure may have a textured, contoured and / or roughened outer surface, for example, as shown in FIGS. 11A-11C.

[00102] The support frame 1703 may include one or more side walls 1704 extending around the periphery of the support frame 1703. The one or more side walls 1704 may surround an open area 1702 within the side walls 1704. The support frame 305 may be comprised of a suitable structural material, such as a plastic (e.g., polypropylene,HDPE, acrylonitrile butadiene styrene (ABS) (e.g., carbon fiber reinforced ABS, glass fiber reinforced ABS, etc.), etc.) and / or a metal (e.g., steel, nickel, etc.) material. The side walls 1704 of the support frame 1703 may be made of a material that is durable enough to withstand prolonged exposure to a liquid electrolyte.

[00103] One or more side walls 1704 may continuously extend around a portion of the periphery of the support frame 1703. Access to the open area 1702 of the support frame 1703 may be provided by one or more openings in the side walls 1704 (not shown in FIGS. 17A and 17B). In some embodiments, the support frame 1703 may have a generally polygonal outer shape, such as a rectangular or square shape, as shown in FIG. 17B. The support frame 1703, having a rectangular or square shape, may have at least three side walls 1704 that extend continuously around three sides of the support frame 1703. The fourth side of the support frame1703 may optionally be open to an open region 1702. Other suitable shapes for the support frame 1703, including shapes having one or more curved side walls 1704, are within the intended scope of the invention.

[00104] The HD electrodes 1701a and 1701b with a layered structure and the support frame 1703 may be placed in a mechanical pressing device 1705, as shown in FIG. 17A. The support frame 1703 may be located between the respective HD electrodes 1701a and 1701b, with the active layers of the electrodes 1701a and 1701b facing outward. Between the side walls 1704 of the support frame 1703 and the corresponding GD electrodes 1701a and 1701b, there may optionally be a sealing material such as a thermoplastic material, an epoxy material, a hot-melt adhesive material, etc. The GD electrodes 1701a and 1701b on the support frame 1703 may be pressed by a pair of heated press platens 1707, as shown by the arrows in FIG. 17A, to bind the GD electrodes 1701a and 1701bwith the support frame 1703 and form a continuous seal between the electrodes 1701a and 1701b and the adjacent side walls 1704 of the support frame 1703. In the embodiment shown in FIG. 17A, both the GD electrodes 1701a and 1701b are simultaneously bonded and sealed with the support frame 1703, although it should be understood that the bonding of the GD electrodes 1701a and 1701b with the support frame 1703 can be performed sequentially using separate pressing steps. In various embodiments, the pressure and / or temperature used to bond the HD electrodes 1701a and 1701b to the support frame 1703 may be less than the pressure and / or temperature used to laminate the HD electrodes 1701a and 1701b.

[00105] In one embodiment, during the mechanical pressing step, the open region 1702 of the support frame 1703 may be fluidly connected to a vacuum source (not shown in FIG. 17A). The vacuum source may be used to provide a negative pressure inopen region 1702 of support frame 1703 that can draw sealing material into the pores of adjacent support layers of GD electrodes 1701a and 1701b. This can help improve the integrity of the seals formed between GD electrodes 1701a and 1701b and support frame 1703.

[00106] In some embodiments, support frame 1703 may include an interior portion extending between side walls 1704 that can define flow fields near respective GD electrodes 1701a and 1701b. Alternatively, an insert, which may be similar to insert 1500 shown in FIGS. 15A and 15B, may be inserted into open region 1702 of support frame 1703 through an opening in support frame 1703. The insert may define flow fields near the respective GD electrodes 1701a and 1701b.

[00107] In some embodiments, the support frame 1703 and / or the insert within the support frame 1703 may be comprised of or include an electrically conductive material.(e.g., a metallic material) that may be in contact with the electrodes 1701a and 1701b. In such embodiments, the support frame 1703 and / or insert may be used as an alternative to or in addition to the electrically conductive current collector embedded in the layered GD electrodes 1701a and 1701b.

[00108] As noted above, in some embodiments, a pair of planar GD electrodes 203 may be bonded to each other and sealed along the edges to form a double-sided sealed GD electrode assembly. However, bending and deforming the GD electrodes to create sealed edges in these configurations may impact their durability and / or performance, and may impose limitations on the flow field. Therefore, as noted above with reference to FIG. 17A and 17B, in some embodiments, a support frame may be used to provide a separate perimeter for the sealed GD electrode assembly. The support frame 1703 may be madefrom any number of suitable materials, such as plastic (e.g., polypropylene, HDPE, acrylonitrile butadiene styrene (ABS) (e.g., carbon fiber reinforced ABS, glass fiber reinforced ABS, etc.), etc.) and / or metal (e.g., steel, nickel, etc.), and can be pressed between the HD electrodes 1701a and 1701b in a layered structure using a pair of heated press platens or other suitable heat sealing device. In this way, the frame material (e.g., ABS, etc.) can be melted at the interface with the respective HD electrodes.

[00109] However, depending on the materials, when hermetically attaching the HD electrodes to the support frame using heated press platens, too large a mismatch in the coefficient of thermal expansion (CTE) may occur. For example, ABS may expand during thermal welding and may subsequently contract upon cooling to room temperature. This change may

[00110] In some embodiments, a first sealing material may be used to attach the layered GD electrodes to the support frame, eliminating the need for heat treatment to create a continuous seal.

[00111] As shown in FIG. 18A, each of the GD electrodes 1801a and 1801b may be a GD electrode with a layered structure that may be formed from a stack of layers comprising at least one active layer and at least one support layer. As specific examples, the GD electrodes 1801a and 1801b may be GD electrodes with a layered structure that may be formed by mechanically pressing at elevated temperature (e.g., hot pressing) a stack of layers comprising at least one active layer and at least onesupport layer, as described above, or may be HD electrodes with a layered structure obtained in another manner. HD electrodes 1801a and 1801b with a layered structure may also include an integrated current collector 1810 that does not extend to the edges where the corresponding HD electrode is to be sealedly attached to the adjacent surface of the support frame 1803. HD electrodes 1801a and 1801b with a layered structure may have planar outer surfaces, as described herein with respect to various embodiments.

[00112] In some embodiments, the support frame 1803 may be made of plastic (e.g., ABS), and the first sealant 1805 may be any of a variety of adhesives or thermoplastic materials, such as ABS cement. Although the bonding of the 1801a and 1801b GD electrodes to the 1803 support frame in this manner does not require any heat treatment, normal operation of the article (e.g., battery) containing such a GD electrode assembly in

[00113] Therefore, in order to make the CTE of the frame closer to the CTE of the MD electrodes, the support frame 1803 in various embodiments can be manufactured using a glass fiber reinforced polymer or a carbon fiber reinforced polymer. Furthermore, in some embodiments, the support frame 1803 can be manufactured from a metal (e.g., carbon steel, nickel plated carbon steel, etc.) or another rigid material (e.g., graphite, etc.).

[00114] Using the first sealant without heat treatment may be appropriate in some cases, but in other cases may pose a risk to durability. In particular, a potential leakage path may exist at the interface between the support frame and the adjacent MD electrode. Especially in cases where

[00115] To reduce such a risk, the support frame 1803, in accordance with some embodiments, may be configured to include elements 1822 for another sealing material, as shown in FIG. 18B. In particular, the elements 1822 integrated into the support frame 1803 may be cutouts or channels configured to receive the second sealant 1805, as shown in FIG. 18C. The second sealant 1805, in accordance with various embodiments, may include any of a number of suitable adhesive materials, such as one or more epoxy resins. To seal any potential leak paths in the 1805 electrode assembly, the second sealant can be epoxy resin,which has been found to be resistant to electrolyte and infiltration.

[00116] In some embodiments, the double-sided sealed GD electrode assembly 1800 may be created by sealingly attaching the planar GD electrode 1801a, 1801b to both sides of the support frame 1803 using a first sealant 1805 and then filling the elements 1822 with a second sealant 1805. Alternatively, in some embodiments, the second sealant may be provided before the GD electrodes are associated with the support frame.

[00117] FIGS. 19A and 19B show a method 1900 for manufacturing double-sided sealed GD electrode assemblies according to an embodiment. First, a support frame 1803 made of a rigid material may be provided. The rigid material may be durable enough to withstand prolonged exposure to a liquid electrolyte (e.g., ABS). In some embodiments, the support frame 1803 may be formed from a plurality of sidewalls of an H-shaped channel that surround the periphery of the interior of the open area. In some embodiments, the support frame 1803 may have at least three side walls of the H-shaped channel that extend continuously to form three sides of a square or rectangle with an open fourth side. The fourth side may be open. Other suitable shapes for the support frame 1803, such as U-shaped shapes, V-shaped shapes, etc., are within the intended scope of the invention.

[00118] In a next step of the method 1900, a layer of a first sealant 1805a (for example, ABS cement) may be applied to the first surface of the support frame 1803. Such application may be performed using any of a variety of dispensing methods.

[00119] In the next step of the method 1900, a first planar GD electrode 1801a may be placed on the first surface of the support frame 1803 containing the first sealant 1805a and left to cure. In some embodiments, the GD electrodes,used in method 1900 are HD electrodes with a layered structure that were manufactured in a separate lamination process. For example, a stack of layers comprising at least one active layer, at least one support layer and a current collector (e.g., copper) could be hot pressed as described herein. In various embodiments, the manufacture of the HD electrodes may include intentionally not placing the current collector in the area with which the first encapsulant will be in contact in order to avoid conductivity in these areas, thereby reducing the risk of a short circuit.

[00120] In a next step, the support structure 1803 can be turned over, and the first encapsulant 1805b can be applied to the opposite surface of the support frame 1803 in a manner similar to the method of applying layer 1805a.

[00121] In the next step of the method 1900, the opposite surface of the support frame 1803 containing the first sealant 1805b may bea second planar GD electrode 1801b is placed and allowed to cure, thereby creating a double-sided sealed GD electrode assembly 1902. In various embodiments, each manufacturing step in the method 1900 may take on the order of minutes. According to some embodiments, the steps used to manufacture the double-sided sealed GD electrode assembly 1902 may be repeated multiple times to create a plurality of assemblies.

[00122] As shown in FIG. 19B, a plurality of HD electrode assemblies (e.g., 1902a, 1902b, etc.) can be stacked vertically in alignment with one another and clamped to form a single, fixedly mounted, large piece 1920. In a next step of method 1900, elements 1822 in support frame 1803 (e.g., channels) can be filled with a second sealant 1832 (e.g., epoxy resin). In various embodiments, the second sealant can be filled on top of fixedly mounted piece 1920 or can be introducedfrom below, such as through an opening in the support frame 1803.

[00123] Although the outer edge of the support frame is shown flush with the HD electrodes in various embodiments, other suitable configurations are within the intended scope of the invention. For example, in some assemblies, the support frames may extend beyond the edges of the associated HD electrodes for various reasons (e.g., to include handling and / or alignment features, to provide mating / interlocking with a battery cell cap, etc.).

[00124] FIGS. 20A and 20B show a method of manufacturing a HD electrode 2000 with a large-area layered structure using an interlocking seam 2001. As shown in FIG. 20A and 20B, the side edges 2002a and 2002b of the pair of electrode structures 2003a and 2003b may be folded over each other as shown in FIG. 20A. Electrode structures 2003a and 2003b may be stacks 320 of layers, such as those shown in FIG. 3B, before lamination. Alternatively, one orBoth electrode structures 2003a and 2003b may be a laminated electrode having a non-laminated edge portion, as shown in FIG. 16A and 16B. To bond together the interlocking side edges 2002a and 2002b and form a seam 2001, as shown in FIG. 20B, mechanical pressure at an elevated temperature may be applied to the interlocking side edges 2002a and 2002b, as indicated by the arrows in FIG. 20A. In this way, a planar HD electrode 2000 with a large-area layered structure may be obtained from stacks of layers and / or electrodes of smaller area. In some embodiments, the seam 2001 obtained by the method illustrated in FIG. 20A and 20B, allows for forming an edge seal for an electrode assembly, such as the double-sided sealed GDE assembly 400 shown in FIGS. 4A-4D.

[00125] FIGS. 21A-21E show a method for manufacturing the double-sided sealed GDE assembly 2100 using a single-step processlamination and sealing by "flat pressing" in accordance with an embodiment of the present invention. FIG. 21A is a perspective view showing a pair of layer stacks 320a and 320b and a spacer 2101 located between the layer stacks 320a and 320b. Each of the layer stacks 320a and 320b may include an active layer 311, a pair of support layers 313, and a current collector 315 between the pair of support layers 313, as described above. The stacks 320a and 320b of layers and the spacer 2101 can be placed in a heat-pressing device configured to apply heat and mechanical pressure to the stacks 320a and 320b of layers and the spacer 2101. The width of the spacer 2101 can be narrower than the width of the support layers 313, so that the spacer 2101 does not reach the first and second peripheral edges 2102 and 2103 on opposite sides of the stacks 320a and 320b of layers. Accordingly, the support layers 313 of the corresponding stacks 320a and 320b of layers can contact each other along the first and second peripheral edges 2102 and 2103stack 320a and 320b of layers. In some embodiments, the current collectors 315 may also not reach the first and second peripheral edges 2102 and 2103 of the stacks 320a and 320b of layers in order to avoid corrosion of the current collectors 315 in the assembled GDE assembly 2100.

[00126] The gasket 2101 may extend up to and / or beyond the third peripheral edge 2104 of the stacks 320a and 320b of layers. Thus, the liner 2101 may be located between the support layers 313 of the respective stacks 320a and 320b of layers along the third peripheral edge 2104. In some embodiments, the liner 2101 may be offset from the fourth peripheral edge 2105 of the stacks 320a and 320b of layers opposite the third peripheral edge 2104. Thus, the support layers 313 of the stacks 320a and 320b of layers may contact each other along the fourth peripheral edge 2105. Alternatively, the liner 2101 may extend before and / or beyond the fourth peripheral edge 2105, so that the liner 2101 may be located betweensupport layers 313 of the respective layer stacks 320a and 320b along the fourth peripheral edge 2105. Between the contacting surfaces of the support layers 313 of the respective layer stacks 320a and 320b, there may optionally be a sealing material as described above with reference to FIG. 5.

[00127] The liner 2101 may consist of a material that does not strongly bond to the adjacent layers of the layer stacks 320a and 320b when heat and pressure are applied to the layer stacks 320a and 320b. Thus, the liner 2101 may also be referred to as a "release layer". The liner / release layer 2101 may include, for example, a film, foil, sheet, membrane, interlayer, or other similar structures, including various combinations thereof. Suitable materials for the liner / release layer 2101 may include metals (e.g., steel, aluminum, etc.), fiber-reinforced plastics (e.g., fiberglass), ceramics, carbon fiber or other graphite compounds, plastics, orpolymers with high thermal stability and combinations thereof. Other suitable materials for the liner / release layer 2101 are within the intended scope of the invention. The liner / release layer 2101 may be a reusable component or may be a consumable / disposable component intended for single use. In some embodiments, the liner / release layer 2101 may have an overall thickness of from about 0.001 to about 2 mm, although liner / release layer 2101 of greater or lesser thickness may be used.

[00128] In a one-step "flat press" lamination and sealing process, the layer stacks 320a and 320b and the liner / release layer 2101 may be laid flat in a heat press device rather than in a mold cavity having one or more contoured interior surfaces configured to provide a three-dimensional shape to the layer stacks 320a and 320b, as described above with reference to FIGS. 5A-5B and 7. UnlikeIn this "flat pressing" process, the heat pressing device may include heated pressing platens with planar surfaces that are configured to apply substantially uniform heat and pressure to the flat outer surfaces of the layer stacks 320a and 320b. The heat pressing device may apply sufficient heat and pressure to the layer stacks 320a and 320b and the spacer / release layer 901 (indicated by the arrows in FIG. 21A) to produce a double-sided sealed GDE assembly 2100 comprising a pair of GD electrodes 203a and 203b with a layered structure with a spacer / release layer 2101 therebetween, as shown in FIG. 21B. The embodiment shown in FIG. 21A and 21B, is a "one-step" process in which individual stacks of layers 320a and 320b are simultaneously laminated and hermetically bonded together (with or without a sealant). After the thermal pressing process, the GD electrodes 203a and 203b arelayered structure may be sealed along at least the first and second peripheral edges 2102 and 2103 of the GDE assembly 2100. In embodiments in which the spacer / release layer 2101 is offset from the fourth peripheral edge 2105, the GD electrodes 203a and 203b with a layered structure may also be sealed along the fourth peripheral edge 2105 of the GDE assembly 2100. An additional outer seal, described above with reference to FIG. 6, may optionally be provided above the sealed bonded edges of the GDE assembly 2100. Active layers 311 may be exposed on the first and second major surfaces 2106 and 2107 of the GDE assembly 2100. As shown in FIG. 21B, after the heat pressing process, the first and second major surfaces 2106 and 2107 of the HDE assembly 2100 may be substantially planar.

[00129] As shown in FIGS. 21C and 21D, the liner / release layer 2101 may be removed from the HDE assembly 2100. FIG. 21C is a perspective view of the HDE assembly 2100, and FIG. 21D is a perspective view of the HDE assembly 2100.a top view of the GDE assembly 2100 is shown with the liner / release layer 2101 removed. A cavity 2018 may be formed in the space between the GD electrodes 203a and 203b from which the liner / release layer 2101 is removed. The sealed edges of the GDE assembly 2100 may surround the cavity 2108. The width of the cavity 2108 may be increased by applying a force to the GDE assembly 2100 to form a pocket-like or pouch-like structure, as shown in FIG. 21E. An insert 1500 may be inserted into the cavity 2018 to define at least one flow field, as described above with reference to FIGS. 15A and 15B.

[00130] In an alternative embodiment, a two-step lamination and sealing process using "flat pressing" may be used to form a double-sided sealed GDE assembly 2100. In the two-step lamination and sealing process using "flat pressing", individual stacks of layers 320a and 320b are first laminated together to form individual GD electrodes 203a and 203b. The individualThe GD electrodes 203a and 203b may have substantially flat outer surfaces. Then, the individual GD electrodes 203a and 203b with the spacer / release layer 2101 located between the GD electrodes 203a and 203b may be fed into a heat-pressing device. After this, the heat-pressing device may be used in the "flat pressing" process, as described above, to hermetically seal the peripheral edges of the GD electrodes 203a and 203b together to obtain an assembly 2100 of a double-sided sealed GD having a spacer / release layer 2101 between the corresponding GD electrodes 203a and 203b, as shown in FIG. 21B. In some embodiments, the same heat-pressing device used for laminating the stacks of layers 320a and 320b may be used to hermetically seal the GD electrodes 203a and 203b using a "flat pressing" process. Alternatively, separate lamination and sealing steps may be used.various heat pressing devices. Following the "flat pressing" sealing process, the liner / release layer 2101 may be removed, as shown in FIGS. 21C and 21D, and the cavity 2108 between the GD electrodes 203A and 203b may be expanded to form a pocket-like or pouch-like structure, as shown in FIG. 21E.

[00131] Various embodiments described and illustrated herein may provide devices and / or methods for use in large-scale energy storage systems, such as long-duration energy storage (LODES) systems, short-duration energy storage (SDES) systems, etc. As an example, various embodiments may provide batteries (e.g., battery 200) for large-scale energy storage systems, such as batteries for long-duration energy storage systems. Renewable energy sources are becoming increasingly prevalent andcost-effective. However, with many renewable energy sources, the problem of variable generation is a barrier to the deployment of renewable energy sources. The impact of variable generation trends in renewable energy sources is partially addressed by combining renewable energy sources with large-scale energy storage systems, such as long-term energy storage systems, short-term energy storage systems, etc. To support the deployment of combined energy generation, transmission, and storage systems (e.g., a power plant that has a renewable energy source paired with a large-scale energy storage system and transmission facilities at any power plant and / or a large-scale energy storage system), devices and methods are needed to support the design and operation of such combined energy generation, transmission, and storage systems, such as variousembodiments of the devices and methods set forth herein.

[00132] A combined power generation, transmission, and storage system is a power plant that includes one or more power generation sources (e.g., one or more renewable power generation sources, one or more non-renewable power generation sources, combinations of renewable and non-renewable power generation sources, etc.), one or more transmission facilities, and one or more large-scale energy storage systems. The transmission facilities at any power plant and / or large-scale energy storage systems are jointly optimized with the power generation and storage system or impose constraints on the design and operation of the power generation and storage system. Combined power generation, transmission, and storage systems may be configured to meet different power output targets with different design and operatinglimitations.

[00133] FIG. 22 shows various examples of systems in which one or more aspects of the various embodiments may be used as part of large-scale energy storage systems, such as long-term energy storage systems, short-term energy storage systems, etc. For example, the various embodiments described herein with reference to FIGS. 1A-93 may be used as batteries for large-scale energy storage systems, such as long-term energy storage systems, short-term energy storage systems, etc., and / or the various electrodes described herein may be used as components for large-scale energy storage systems. As used herein, the term "long-term energy storage system" may mean a large-scale energy storage system configured to have a nominal operating time (energy / power ratio) of 24hours (h) or more, such as a nominal operating time of 24 hours, a nominal operating time of 24 hours to 50 hours, a nominal operating time of more than 50 hours, a nominal operating time of 24 hours to 150 hours, a nominal operating time of more than 150 hours, a nominal operating time of 24 hours to 200 hours, a nominal operating time of more than 200 hours, a nominal operating time of 24 hours to 500 hours, a nominal operating time of more than 500 hours, etc.

[00134] FIG. 22 shows an example of a system in which one or more aspects of various embodiments of the invention may be used as part of a large-scale energy storage system. As a specific example, a large-scale energy storage system incorporating one or more aspects of various embodiments of the invention may be a long-term energy storage system 2404. As an example, the 2404 long-term storage systemenergy may include various embodiments of batteries described herein, various electrodes described herein, etc. The long-term energy storage system 2404 may be electrically connected to the wind farm 2402 and one or more transmission facilities 2406. The wind farm 2402 may be electrically connected to the transmission facilities 2406. The transmission facilities 2406 may be electrically connected to the grid 2408. The wind farm 2402 may generate energy, and the wind farm 2402 may output the generated energy to the long-term energy storage system 2404 and / or the transmission facilities 2406. The long-term energy storage system 2404 may store energy received from the wind farm 2402 and / or the transmission facilities 2406. The long-term energy storage system 2404 may output the stored energy to the transmission facilities 2406. The 2406 transmission facilities may output power received from one or both wind turbines.power plants 2402 and long-term energy storage systems 2404, to the grid 2408 and / or receive energy from the grid 2408 and output this energy to the long-term energy storage system 2404. Together, the wind power plant 2402, the long-term energy storage system 2404 and the transmission facilities 2406 can form a power plant 2400, which can be a combined energy generation, transmission and storage system. The energy generated by the wind power plant 2402 can be directly fed to the grid 2408 through the transmission facilities 2406 or can first be stored in the long-term energy storage system 2404. In some cases, the energy fed to the grid 2408 can come entirely from the wind power plant 2402, come entirely from the long-term energy storage system 2404, or from a combination of the wind power plant 2402 and the long-term energy storage system 2404. Transmission of energy from a combined cycle power plant 2400 consisting of a wind power plant 2402 and a long-term system 2404energy storage, may manage according to a set long-term (multi-day or even multi-year) schedule, or may manage according to a day-ahead market (with 24 hours' advance notice), or may manage according to an hour-ahead market, or may manage in response to real-time pricing signals.

[00135] As one example of the operation of the power plant 2400, the long-term energy storage system 2404 may be used to convert the energy generated by the wind farm 2402 and provide "firm" power to the power plant. In one such example, the wind farm 2402 may have a peak output (power) of 260 megawatts (MW) and a capacity factor (CF) of 41%. The 2404 long-term energy storage system may have a rated capacity (power) of 106 MW, a nominal operating time (energy / power ratio) of 150 hours (h), and a nominal energy consumption of 15,900megawatt-hours (MWh). In another such example, wind farm 2402 may have a peak output (power) of 300 MW and a capacity factor (CF) of 41%. Long-term energy storage system 2404 may have a rated output of 106 MW, a runtime in nominal mode (energy / power ratio) of 200 h and a nominal energy consumption of 21,200 MWh. In another such example, wind farm 2402 may have a peak output (power) of 176 MW and a capacity factor (CF) of 53%. Long-term energy storage system 2404 may have a rated output (power) of 88 MW, a runtime in nominal mode (energy / power ratio) of 150 h and a nominal energy consumption of 13,200 MWh. In another such example, wind farm 2402 may have a peak output (power) of 277 MW and a capacity factor (CF) of 41%. Long-term energy storage system 2404 may have a rated output (power) of 97 MW, an operating time at ratedmode (energy / power ratio) of 50 hours and a nominal power consumption of 4850 MWh. In another such example, wind farm 2402 may have a peak output (power) of 315 MW and a capacity factor (CF) of 41%. Long-term energy storage system 2404 may have a nominal output (power) of 110 MW, an operating time in nominal mode (energy / power ratio) of 25 hours and a nominal power consumption of 2750 MWh.

[00136] FIG. 23 shows an example of a system in which one or more aspects of various embodiments of the invention may be used as part of a large-scale energy storage system. As a specific example, a large-scale energy storage system incorporating one or more aspects of various embodiments of the invention may be long-term energy storage system 2404. As an example, long-term energy storage system 2404 may include various embodiments of batteries,described herein, various electrodes described herein, etc. The system of FIG. 24 may be similar to the system of FIG. 22 except that the photovoltaic (PV) power plant 2502 may be replaced by a wind power plant 2402. The long-term energy storage system 2404 may be electrically connected to the photovoltaic power plant 2502 and one or more transmission facilities 2406. The photovoltaic power plant 2502 may be electrically connected to the transmission facilities 2406. The transmission facilities 2406 may be electrically connected to the grid 2408. The photovoltaic power plant 2502 may generate energy and the photovoltaic power plant 2502 may output the generated energy to the long-term energy storage system 2404 and / or the transmission facilities 2406. The long-term energy storage system 2404 may store energy received from the photovoltaic power plant 2502 and / or transmission facilities 2406. The long-term storage system 2404energy can output the stored energy to the transmission facilities 2406. The transmission facilities 2406 can output the energy received from one or both of the photovoltaic power plants 2502 and the long-term energy storage system 2404 to the grid 2408 and / or can receive energy from the grid 2408 and output this energy to the long-term energy storage system 2404. Together, the photovoltaic power plant 2502, the long-term energy storage system 2404 and the transmission facilities 2406 can form a combined power plant 2500, which can be a combined energy generation, transmission and storage system. The energy generated by the photovoltaic power plant 2502 can be directly fed to the grid 2408 through the transmission facilities 2406 or can first be stored in the long-term energy storage system 2404. In some cases, the energy supplied to the grid 2408 may come entirely from the photovoltaic power plant 2502, come entirely from the long-term storage system 2404energy or from a combination of the photovoltaic power plant 2502 and the long-term energy storage system 2404. The transmission of energy from the combined power plant 2500, consisting of the photovoltaic power plant 2502 and the long-term energy storage system 2404, may be controlled in accordance with a set long-term (multi-day or even multi-year) schedule, or may be controlled in accordance with a day-ahead market (with 24 hours' advance notice), or may be controlled in accordance with an hour-ahead market, or may be controlled in response to real-time pricing signals.

[00137] As one example of the operation of the power plant 2500, the long-term energy storage system 2404 may be used to convert the energy generated by the photovoltaic power plant 2502 and provide "firm" power to the power plant. In one such example, the photovoltaic power plant 2502 may have a peak output (power) of 490 MW andcapacity factor (CF) of 24%. The long-term energy storage system 2404 may have a rated capacity (power) of 340 MW, a nominal operating time (energy / power ratio) of 150 h, and a nominal energy consumption of 51,000 MWh. In another such example, the photovoltaic power plant 2502 may have a peak production (power) of 680 MW and a capacity factor (CF) of 24%. The long-term energy storage system 2404 may have a rated capacity (power) of 410 MW, a nominal operating time (energy / power ratio) of 200 h, and a nominal energy consumption of 82,000 MWh. In another such example, the photovoltaic power plant 2502 may have a peak production (power) of 330 MW and a capacity factor (CF) of 31%. The 2404 long-term energy storage system may have a rated capacity (power) of 215 MW, a nominal operating time (energy / power ratio) of 150 h, and a nominal energy consumption of 32,250 MWh.In another such example, the photovoltaic power plant 2502 may have a peak output (power) of 510 MW and a capacity factor (CF) of 24%. The long-term energy storage system 2404 may have a rated output (power) of 380 MW, a runtime in nominal mode (energy / power ratio) of 50 hours, and a nominal energy consumption of 19,000 MWh. In another such example, the photovoltaic power plant 2502 may have a peak output (power) of 630 MW and a capacity factor (CF) of 24%. The long-term energy storage system 2404 may have a rated output (power) of 380 MW, a runtime in nominal mode (energy / power ratio) of 25 hours, and a nominal energy consumption of 9,500 MWh.

[00138] In FIG. 24 shows an example of a system in which one or more aspects of various embodiments of the invention may be used as part of a large-scale energy storage system. As a specific example, the large-scale storage systemenergy, including one or more aspects of various embodiments of the invention, may be a long-term energy storage system 2404. By way of example, the long-term energy storage system 2404 may include various embodiments of batteries described herein, various electrodes described herein, etc. The system of FIG. 24 may be similar to the systems of FIGS. 22 and 23 except that the wind farm 2402 and the photovoltaic (PV) power plant 2502 may both be power generators operating together at the power plant 2600. Together, the photovoltaic power plant 2502, the wind farm 2402, the long-term energy storage system 2404, and the transmission facilities 2406 may be a combined power plant 2600, which is a combined energy generation, transmission, and storage system. The energy generated by the photovoltaic power plant 2502 and / orwind power plant 2402, may be directly fed into grid 2408 via transmission facilities 2406 or may first be stored in long-term energy storage system 2404. In some cases, the energy fed into grid 2408 may be supplied entirely by photovoltaic power plant 2502, supplied entirely by wind power plant 2402, supplied entirely by long-term energy storage system 2404, or from a combination of photovoltaic power plant 2502, wind power plant 2402, and long-term energy storage system 2404. The transmission of energy from the combined cycle power plant 2600, consisting of the wind power plant 2402, the photovoltaic power plant 2502 and the long-term energy storage system 2404, may be controlled according to a set long-term (multi-day or even multi-year) schedule, or may be controlled according to the day-ahead market (with 24 hours' advance notice), or may be controlled according to the hour-ahead market,or may be controlled in response to real-time pricing signals.

[00139] As one example of the operation of the power plant 2600, the long-term energy storage system 2404 may be used to convert the energy generated by the wind power plant 2402 and the photovoltaic power plant 2502 and provide "firm" power to the power plant. In one such example, the wind power plant 2402 may have a peak output (power) of 126 MW and a capacity factor (CF) of 41%, and the photovoltaic power plant 2502 may have a peak output (power) of 126 MW and a capacity factor (CF) of 24%. The long-term energy storage system 2404 may have a rated output (power) of 63 MW, an operating time in the rated mode (energy / power ratio) of 150 h and a rated energy consumption of 9450 MWh. In another such example, wind farm 2402 may have a peak output (power) of 170 MW and a capacity factor ofThe solar power plant 2502 may have a peak output (power) of 110 MW and a capacity factor (CF) of 24%. The long-term energy storage system 2404 may have a rated output (power) of 57 MW, a nominal operating time (energy / power ratio) of 200 h, and a nominal energy consumption of 11,400 MWh. In another such example, the wind power plant 2402 may have a peak output (power) of 105 MW and a capacity factor (CF) of 51%, and the solar power plant 2502 may have a peak output (power) of 70 MW and a capacity factor (CF) of 31%. The long-term energy storage system 2404 may have a rated capacity (power) of 61 MW, a nominal operating time (energy / power ratio) of 150 h, and a nominal energy consumption of 9150 MWh. In another such example, the wind farm 2402 may have a peak output (power) of 135 MW and a capacity factor (CF)41%, and the photovoltaic power plant 2502 may have a peak output (power) of 90 MW and a capacity factor (CF) of 24%. The long-term energy storage system 2404 may have a rated output (power) of 68 MW, a nominal operating time (energy / power ratio) of 50 h, and a rated energy consumption of 3400 MWh. In another such example, the wind power plant 2402 may have a peak output (power) of 144 MW and a capacity factor (CF) of 41%, and the photovoltaic power plant 2502 may have a peak output (power) of 96 MW and a capacity factor (CF) of 24%. The long-term energy storage system 2404 may have a nominal capacity (power) of 72 MW, a nominal operating time (energy / power ratio) of 25 hours, and a nominal energy consumption of 1800 MWh.

[00140] FIG. 25 shows an example of a system in which one or more aspects of various embodiments of the invention may be used as part ofa large-scale energy storage system. As a specific example, a large-scale energy storage system incorporating one or more aspects of various embodiments of the invention may be a long-term energy storage system 2404. As an example, the long-term energy storage system 2404 may include various embodiments of batteries described herein, various electrodes described herein, etc. The long-term energy storage system 2404 may be electrically connected to one or more transmission facilities 2406. In this way, the long-term energy storage system 2404 may operate "offline" to regulate energy in accordance with market prices and / or to avoid transmission constraints. The long-term energy storage system 2404 may be electrically connected to one or more transmission facilities 2406. The transmission facilities 2406 may be electrically connected to a grid 2408. The system 2404long-term energy storage system 2404 may store energy received from transmission facilities 2406. Long-term energy storage system 2404 may output stored energy to transmission facilities 2406. Transmission facilities 2406 may output energy received from long-term energy storage system 2404 to grid 2408 and / or may receive energy from grid 2408 and output this energy to long-term energy storage system 2404.

[00141] Together, long-term energy storage system 2404 and transmission facilities 2406 may comprise power plant 900. As an example, power plant 900 may be located downstream of a transmission constraint, close to the location of electric power consumption. In such an example of downstream power plant 2700, long-term energy storage system 2404 may have an operating duration of 24 to 500 hours and may undergo one or more full discharges per year to support peak electric power consumption values ​​during periods when throughputcapacity is insufficient to serve consumers. Furthermore, in such an example of a downstream power plant 2700, the long-term energy storage system 2404 may undergo multiple shallow discharges (daily or at a higher frequency) to determine the difference between night-time and daytime electricity prices and reduce the overall cost of electricity service for the consumer. As a further example, the power plant 2700 may be located upstream of a transmission constraint, close to the location of electricity generation. In such an example of an upstream power plant 2700, the long-term energy storage system 2404 may have an operating duration of between 24 and 500 hours and may undergo one or more full charges per year to absorb excess generation at times when transmission capacity is insufficient to distribute electricity to consumers. Furthermore, in such an example of an upstream power plant2700 The long-term energy storage system 2404 may be subject to multiple shallow charges and discharges (daily or at a higher frequency to determine the difference between night-time and daytime electricity prices and to maximize the value of electricity generation by the means for its production.

[00142] FIG. 26 shows an example of a system in which one or more aspects of various embodiments of the invention may be used as part of a large-scale energy storage system. As a specific example, a large-scale energy storage system incorporating one or more aspects of various embodiments of the invention may be a long-term energy storage system 2404. As an example, the long-term energy storage system 2404 may include various embodiments of batteries described herein, various electrodes described herein, etc. The long-term energy storage system 2404 maybe electrically connected to a commercial and industrial (C&I) consumer 2802, such as a data center, a factory, etc. The long-term energy storage system 2404 can be electrically connected to one or more transmission facilities 2406. The transmission facilities 2406 can be electrically connected to a grid 2408. The transmission facilities 2406 can receive energy from the grid 2408 and output this energy to the long-term energy storage system 2404. The long-term energy storage system 2404 can store the energy received from the transmission facilities 2406. The long-term energy storage system 2404 can output the stored energy to the commercial and industrial (C&I) consumer 2802. In this way, the long-term energy storage system 2404 can operate to transform the electric power received from the grid 2408 in accordance with the consumption pattern of the commercial and industrial (C&I) consumer 2802.

[00143] Together, the long-term energy storage system 2404 and the transmission facilities 2406 may comprise the power plant 2800.As an example, the power plant 2800 may be located close to the point of consumption of electricity, i.e., close to the commercial consumer 2802, for example, between the grid 2408 and the commercial consumer 2802. In such an example, the long-term energy storage system 2404 may have an operating time of 24 to 500 hours and may purchase electricity in the markets and, thus, charge the long-term energy storage system 2404 at a time when electricity is cheaper. The long-term energy storage system 2404 may then discharge to provide electricity to the commercial customer 2802 at a time when the market price is high, which offsets the market purchases of the commercial customer 2802. As an alternative configuration, instead of being located between the grid 2408 and the commercial customer 2802, the power plant 2800 may be located between a renewable source, such as a photovoltaic power plant,wind farm, etc., and transmission facilities 2406 may be connected to a renewable source. In such an alternative example, long-term energy storage system 2404 may have an operating duration of 24 to 500 hours, and long-term storage system 2404 may be charged during times when renewable energy is available. Long-term energy storage system 2404 may then discharge to provide commercial customer 2802 with renewable generated electric power to cover some or all of the commercial customer 2802's electric power needs.

[00144] FIG. 27 shows an example of a system in which one or more aspects of various embodiments of the invention may be used as part of a large-scale energy storage system. As a specific example, a large-scale energy storage system incorporating one or more aspects of various embodiments of the invention may be a system 2404long-term energy storage. As an example, long-term energy storage system 2404 may include various embodiments of batteries described herein, various electrodes described herein, etc. Long-term energy storage system 2404 may be electrically connected to wind power plant 2402 and one or more transmission facilities 2406. Wind power plant 2402 may be electrically connected to transmission facilities 2406. Transmission facilities 2406 may be electrically connected to business and industrial customer 2802. Wind power plant 2402 may generate energy, and wind power plant 2402 may output the generated energy to long-term energy storage system 2404 and / or transmission facilities 2406. Long-term energy storage system 2404 may store energy received from wind power plant 2402.

[00145] The long-term energy storage system 2404 can output stored energy to objects 2406transmission. Transmission facilities 2406 can output energy received from one or both of wind power plants 2402 and long-term energy storage system 2404 to commercial and industrial consumer 2802. Together, wind power plant 2402, long-term energy storage system 2404 and transmission facilities 2406 can form power plant 2900, which can be a combined energy generation, transmission and storage system. Energy generated by wind power plant 2402 can be directly supplied to commercial and industrial consumer 2802 through transmission facilities 2406 or can first be stored in long-term energy storage system 2404. In some cases, the energy supplied to the commercial and industrial consumer 2802 may be supplied entirely from the wind power plant 2402, supplied entirely from the long-term energy storage system 2404, or from a combination of the wind power plant 2402 and the long-term energy storage system 2404. The long-term energy storage system 2404 may beused to convert the electrical energy generated by the wind farm 2402 to match the consumption pattern of the business customer 2802. In one such example, the long-term energy storage system 2404 may have an operating duration of between 24 and 500 hours and may be charged during times when the renewable energy production by the wind farm 2402 exceeds the electrical energy consumption of the business customer 2802. The long-term energy storage system 2404 may then discharge when the renewable energy production by the wind farm 2402 does not match the electrical energy consumption of the business customer 2802 to provide the business customer 2802 with guaranteed renewable energy that offsets some or all of the electrical energy consumption of the business customer 2802.

[00146] FIG. 28 shows an example of a system in which one or more aspectsvarious embodiments of the invention may be used as part of a large-scale energy storage system. As a specific example, a large-scale energy storage system incorporating one or more aspects of the various embodiments of the invention may be a long-term energy storage system 2404. As an example, the long-term energy storage system 2404 may include the various embodiments of batteries described herein, the various electrodes described herein, etc. The long-term energy storage system 2404 may be part of a power plant 3000 that is used to integrate large amounts of renewable energy generation into a microgrid and to match the renewable energy generation by, for example, a photovoltaic power plant 2502 and a wind power plant 2402, with existing thermal energy generation by, for example, a thermal power plant 3002 (e.g.,gas generator plant, coal power plant, diesel generator plant, etc., or a combination of thermal energy generation methods), while renewable energy generation and thermal energy generation provide electricity consumption by the commercial and industrial consumer 2802 with a high degree of availability. Microgrids, such as microgrids formed by the power plant 3000 and the thermal power plant 3002, can provide availability of 90% or higher. Energy generated by the photovoltaic power plant 2502 and / or the wind power plant 2402 can be directly supplied to the commercial and industrial consumer 2802 or can first be stored in the long-term energy storage system 2404.

[00147] In some cases, the energy supplied to the commercial and industrial consumer 2802 may be supplied entirely from the photovoltaic power plant 2502, supplied entirely from the wind power plant 2402, supplied entirely from the long-term energy storage system 2404,come entirely from the thermal power plant 3002 or from a combination of the photovoltaic power plant 2502, the wind power plant 2402, the long-term energy storage system 2404 and / or the thermal power plant 3002. As an example, the long-term energy storage system 2404 of the power plant 3000 may have an operating time of from 24 h to 500 h. As a specific example, the electricity consumption of the commercial and industrial consumer 2802 may have a peak power of 100 MW, the long-term energy storage system 2404 may have a rated power of 14 MW and an operating time in nominal mode of 150 h, the cost of natural gas per million British thermal units (MBTU) may be $6, and the share of renewable energy sources may be 58%. As another specific example, the commercial and industrial consumer 2802 may have a peak power of 100 MW, the long-term energy storage system 2404 may have a nominal power of 25MW and a nominal operating time of 150 hours, the cost of natural gas per million British thermal units (MBTU) may be $8, and the share of renewable energy sources may be 65%.

[00148] FIG. 29 shows an example of a system in which one or more aspects of various embodiments of the invention may be used as part of a large-scale energy storage system. As a specific example, a large-scale energy storage system incorporating one or more aspects of various embodiments of the invention may be a long-term energy storage system 2404. As an example, a long-term energy storage system 2404 may include various embodiments of batteries described herein, various electrodes described herein, etc. A long-term energy storage system 2404 may be used to supplement a nuclear power plant 3102 (or other inflexible facilitygeneration, such as a thermal power plant, a biofuel power plant, etc., and / or any other type of installation having a ramp rate below 50% of the rated capacity in one hour and with a high capacity factor of 80% or higher) to add flexibility to the overall capacity of the power plant 3100 consisting of a combination of the long-term energy storage system 2404 and the nuclear power plant 3102. The nuclear power plant 3102 can operate at a high capacity factor and with maximum efficiency while the long-term energy storage system 2404 can be charged and discharged to efficiently convert the output power of the nuclear power plant 3102 in accordance with customer electricity consumption and / or the market price for electricity. As an example, the long-term energy storage system 2404 of the power plant 3100 can have an operating duration of from 24 h to 500 h. In one specific example, the nuclear power plant 3102may have a rated capacity of 1000 MW and nuclear power plant 3102 may be forced to operate for long periods of minimal stable output or even idle due to depressed market prices for electricity. Long-term energy storage system 2404 may avoid plant shutdowns and is charged during periods of low market prices; and long-term energy storage system 2404 may subsequently discharge and increase overall electricity output during periods of elevated market prices.

[00149] FIG. 30 shows an example of a system in which one or more aspects of various embodiments of the invention may be used as part of a large-scale energy storage system. As a specific example, a large-scale energy storage system incorporating one or more aspects of various embodiments of the invention may be a long-term energy storage system 2404. As an example, long-term storage system 2404energy may include various embodiments of batteries described herein, various electrodes described herein, etc. The long-term energy storage system 2404 may be paired with the short-term energy storage system 3202. Together, the long-term energy storage system 2404 and the short-term energy storage system 3202 may comprise the power plant 3200. As an example, the long-term energy storage system 2404 and the short-term energy storage system 3202 may be jointly optimized, wherein the long-term energy storage system 2404 may provide various services, including long-term backup and / or coping with multi-day fluctuations (e.g., multi-day fluctuations in market prices, renewable energy generation, electricity consumption, etc.), and the short-term energy storage system 3202 may provide various services, including fast ancillary services (e.g.,voltage control, frequency regulation, etc.) and / or overcoming intraday fluctuations (e.g., intraday fluctuations in market prices, renewable energy generation, electricity consumption, etc.). Short-term energy storage systems 3202 may have an operating time of less than 10 hours and an energy conversion efficiency of greater than 80%. Long-term energy storage systems 2404 may have an operating time of 24 to 500 hours and an energy conversion efficiency of greater than 40%. In one such example, long-term energy storage system 2404 may have an operating time of 150 hours and support a customer's electricity consumption for a week in the event of undergeneration of renewable electricity. Long-term energy storage system 2404 may also support a customer's electricity consumption during intraday undergeneration of renewable electricity, complementing the capabilities of short-term storage system 3202.energy. In addition, the short-term energy storage system 3202 can supply consumers during intraday generation shortages and ensure the maintenance of normal power supply parameters and provide quality services such as voltage control and frequency regulation.

[00150] Various embodiments may include an electrode assembly comprising: a first electrode on a first side of the electrode assembly, wherein the first electrode comprises a planar portion adjacent to a lower peripheral edge and to first and second lateral peripheral edges of the electrode assembly, a convex portion extending from the planar portion to a raised portion of the first electrode located in a central region and extending to an upper peripheral edge of the electrode assembly; and a second element on a second side of the electrode assembly opposite the first side, wherein the planar portion of the first electrode contacts a surface of the second element and is sealed thereto, andthe electrode assembly comprises an internal chamber defined between the inner surface of the first electrode and the inner surface of the second element. In some embodiments, the second element comprises a second electrode on a second side of the electrode assembly, wherein the second electrode comprises a planar portion adjacent to the lower peripheral edge and to the first and second lateral peripheral edges of the electrode assembly, a convex portion extending from the planar portion to a raised portion of the second electrode located in the central region of the second electrode and extending to the upper peripheral edge of the electrode assembly. In some embodiments, each of the first and second electrodes comprises an electrode for an oxygen reduction reaction (ORR). In some embodiments, each of the first and second electrodes comprises a gas diffusion electrode (GD) with a layered structure containing an active layer and at least one support layer. In some embodimentsIn some embodiments, the active layers of the first and second electrodes comprise a hydrophilic surface, and the support layers of the first and second electrodes comprise a hydrophobic surface. In some embodiments, each of the first and second electrodes comprises a gas diffusion electrode (GD) with a layered structure having an integrated current collector. In some embodiments, the current collectors are in electrical contact with a busbar located in the internal chamber of the electrode assembly. In some embodiments, the active layers of the first and second electrodes are located on the respective outer surfaces of the electrode assembly. In some embodiments, the active layers of the first and second electrodes do not extend to the lower peripheral edge and the first and second lateral peripheral edges of the electrode assembly. In some embodiments, the active layers of the first electrode and the second electrode do not extend to the upper peripheral edge of the electrode assembly, and wherein each ofgas diffusion electrodes with a layered structure comprise a strip of electrochemically inert material located between the upper edge of the respective active layers and the upper peripheral edge of the electrode assembly. In some embodiments of the invention, the electrode assembly may also comprise an insert located in the internal chamber of the electrode assembly and in contact with the respective support layers of the first and second electrodes, wherein the insert defines air flow fields through the respective support layers of the first and second electrodes. In some embodiments, the raised central region of the first electrode comprises a textured, contoured and / or roughened three-dimensional shape. In some embodiments, the electrode assembly may also comprise a sealing material located between the planar portion of the first electrode and the surface of the second element. In some embodiments, the sealing material comprisesat least one of a thermoplastic material, fluorinated ethylene propylene (FEP), polytetrafluoroethylene (PTFE), an epoxy material, or a hot melt adhesive material. In some embodiments, the electrode assembly may also comprise a sealing material along the lower peripheral edge and the first and second lateral peripheral edges of the electrode assembly. In some embodiments, the sealing material comprises at least one of an epoxy paint, a dispensed epoxy material and epoxy impregnation, a clamp, a collar, and an epoxy-coated tape. In some embodiments, the second side of the electrode assembly comprises a planar surface. In some embodiments, the second element comprises a support substrate comprised of an electrochemically inert material. Some embodiments may include a battery comprising: a housing; a liquid electrolyte within the housing; an anode electrode within the housing, at least partiallyimmersed in a liquid electrolyte; and an electrode assembly according to any one or more embodiments described in this paragraph, wherein the electrode assembly is located within a housing, wherein such electrode assembly is at least partially immersed in a liquid electrolyte.

[00151] Various embodiments may include a method of manufacturing an electrode assembly, comprising: providing a stack of layers comprising at least one active layer and at least one support layer; forming a gas diffusion electrode with a layered structure by applying pressure and heat to the stack of layers, wherein the gas diffusion electrode with a layered structure comprises a planar portion adjacent to a lower peripheral edge and to first and second lateral peripheral edges of the electrode, a convex portion extending from the planar portion to a raised portion of the electrode located in a central region and extending near an upper peripheral edge of the electrode; and bondinga gas diffusion electrode with a layered structure with a second element for hermetically attaching a planar portion to the second element and forming an electrode assembly having an internal chamber between the gas diffusion electrode with a layered structure and the second element. In some embodiments, the gas diffusion electrode with a layered structure is formed as a first gas diffusion electrode with a layered structure, and the second element is formed as a second gas diffusion electrode with a layered structure. In some embodiments, the method may also include: providing a second stack of layers comprising at least one active layer and at least one support layer; forming a second gas diffusion electrode with a layered structure by applying pressure and heat to the second stack of layers, wherein the second gas diffusion electrode with a layered structure comprises a planar portion adjacent to a lower peripheral edge and first and second lateralperipheral edges of the second gas diffusion electrode with a layered structure, a convex portion extending from the planar portion to a raised portion of the second gas diffusion electrode with a layered structure located in the central region and extending near the upper peripheral edge of the second gas diffusion electrode with a layered structure, and wherein bonding the first gas diffusion electrode with a layered structure to the second gas diffusion electrode with a layered structure includes forming a seal between the planar portion of the first gas diffusion electrode with a layered structure and the planar portion of the second gas diffusion electrode with a layered structure to form an electrode assembly having an internal chamber between the first gas diffusion electrode with a layered structure and the second gas diffusion electrode with a layered structure. In some embodiments, the first and second gas diffusion electrodes with a layered structure form andbonded together simultaneously. In some embodiments, the first and second gas diffusion electrodes with a layered structure are formed and bonded to each other by feeding a first stack of layers and a second stack of layers into a forming device and hot pressing the first stack of layers and the second stack of layers within the forming device to obtain an electrode assembly comprising a first gas diffusion electrode with a layered structure bonded to a second gas diffusion electrode with a layered structure. In some embodiments, bonding the first gas diffusion electrode with a layered structure to the second gas diffusion electrode with a layered structure includes: feeding the first gas diffusion electrode with a layered structure and the second gas diffusion electrode with a layered structure in a mechanical pressing device; and applying mechanical pressure and heat to planar portions of the first gas diffusion electrode with a layered structure and the seconda gas diffusion electrode with a layered structure using a mechanical pressing device to form a hermetic joint between a planar portion of a first gas diffusion electrode with a layered structure and a planar portion of a second gas diffusion electrode with a layered structure. In some embodiments, the first gas diffusion electrode with a layered structure and the second gas diffusion electrode with a layered structure are formed on a continuous sheet that is assembled and hermetically secured along at least first and second side sides of the electrodes.

[00152] Various embodiments may include a method of manufacturing an electrode assembly, comprising: hermetically attaching the first gas diffusion electrode with a layered structure to one or more side walls of a support frame on a first side of the support frame such that the first gas diffusion electrode with a layered structure extends along the first side of the inner portionan open region of one or more side walls; and sealingly attaching a second layered electrode to one or more side walls on a second side of the support frame such that the second layered gas diffusion electrode extends along the second side of the inside of the open region of the one or more side walls. In some embodiments, the first layered gas diffusion electrode and the second layered gas diffusion electrode are sealingly attached to the side walls under a negative pressure environment to promote penetration of the sealing material into the pores of the first and second layered gas diffusion electrodes. Various embodiments may include a method of manufacturing a large-area layered gas diffusion electrode, comprising: folding unlaminated portions of a first stack of layers and a second stack of layers to obtain mutuallyadhering lateral edges of a first stack of layers and a second stack of layers, each stack of layers comprising at least one active layer and at least one support layer; and applying pressure and heat to the interlocking lateral edges to join the interlocking lateral edges and form a seam joining the first stack of layers and the second stack of layers.

[00153] Various embodiments may include a method of making an electrode assembly, comprising: providing a first stack of layers comprising at least one active layer and at least one support layer, and a second stack of layers comprising at least one active layer and at least one support layer; forming a first gas diffusion electrode with a layered structure by applying pressure and heat to the first stack of layers and a second gas diffusion electrode with a layered structure by applying pressure and heat to the second stack of layers; bonding the first gas diffusion electrodean electrode with a layered structure with a second gas diffusion electrode with a layered structure to form an electrode assembly having a spacer between the first gas diffusion electrode with a layered structure and the second gas diffusion electrode with a layered structure; and removing the spacer from the electrode assembly to form a cavity in the electrode assembly between the first gas diffusion electrode with a layered structure and the second gas diffusion electrode with a layered structure.

[00154] In some embodiments, the first and second gas diffusion electrodes with a layered structure are formed and bonded together simultaneously, and the method also includes: feeding the first stack of layers, the second stack of layers, and the spacer into a heat pressing device such that the spacer is located between the first stack of layers and the second stack of layers, wherein the heat pressing device is used to apply sufficient heat and pressure to simultaneously form and bond together the first andsecond gas diffusion electrodes with a layered structure. In some embodiments, the method may also include: feeding the first gas diffusion electrode with a layered structure, the second gas diffusion electrode with a layered structure, and a spacer into a heat-pressing device such that the spacer is located between the first gas diffusion electrode with a layered structure and the second gas diffusion electrode with a layered structure, wherein the heat-pressing device is used to apply sufficient heat and pressure to bond the first gas diffusion electrode with a layered structure to the second gas diffusion electrode with a layered structure. Various embodiments may include an electrode assembly comprising: a support frame having one or more side walls located around the periphery of the support frame and surrounding the interior of the open area of ​​the one or more side walls; the first gas diffusion electrode with a layeredstructure, hermetically attached to one or more side stacks of the support frame on a first surface of the support frame; and a second gas diffusion electrode with a layered structure, hermetically attached to one or more side walls of the support frame on an opposite surface of the support frame. In some embodiments, the first and second gas diffusion electrodes with a layered structure are hermetically attached to the respective first surface and the opposite surface of the support frame using a first sealing material and without heat treatment. In some embodiments, the first and second gas diffusion electrodes with a layered structure are hermetically attached to the respective first surface and the opposite surface of the support frame using a first sealing material and with heat treatment.

[00155] In some embodiments, one or more supporting walls of the support frame comprise acrylonitrile butadiene styrene (ABS), and whenwherein the first sealing material comprises ABS cement. In some embodiments, one or more side walls comprise three H-channel structures that are configured to form at least three sides of a rectangle. In some embodiments, the rectangle comprises an open region configured to receive an insert defining at least one flow field for one or more of the first gas diffusion electrode with a layered structure and the second gas diffusion electrode with a layered structure. In some embodiments, the H-channel structures are configured to receive a second sealing material. In some embodiments, the second sealing material comprises epoxy resin. In some embodiments, each of the first and second gas diffusion electrodes with a layered structure comprises at least one active layer, at least one support layer, andan integrated current collector. Some embodiments may include a battery comprising: a housing; a liquid electrolyte within the housing; an anode electrode within the housing at least partially immersed in the liquid electrolyte; and an electrode assembly according to any one or more embodiments described in this paragraph, wherein the electrode assembly is within the housing, wherein such electrode assembly is at least partially immersed in the liquid electrolyte.

[00156] The foregoing descriptions of the methods are merely illustrative examples and do not mean or imply that the steps of the various embodiments must be performed in the order presented. As will be appreciated by one of skill in the art, the steps in the foregoing embodiments may be performed in any order. Words such as "then," "then," "next," etc. are not necessarily intended to limit the order of the steps; these words may be used for guidancereader with a description of the methods. Furthermore, any reference to elements of a claim in the singular should not be construed as limiting the element to the singular.

[00157] Furthermore, any step of any embodiment described herein can be used in any other embodiment. The previous description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein are applicable to other aspects within the scope of the present invention. Thus, the present invention is not intended to be limited to the aspects disclosed herein, but its scope is to be accorded the broadest possible meaning consistent with the principles and novel features disclosed herein.

Claims

1. An electrode assembly containing: a first electrode on a first side of the electrode assembly, wherein the first electrode comprises a planar portion adjacent to the lower peripheral edge and to the first and second lateral peripheral edges of the electrode assembly, a convex portion extending from the planar portion to a raised portion of the first electrode located in the central region and extending to the upper peripheral edge of the electrode assembly; and a second element on a second side of the electrode assembly opposite the first side, wherein the planar portion of the first electrode contacts the surface of the second element and is hermetically connected to it, and the electrode assembly comprises an internal chamber formed between the inner surface of the first electrode and the inner surface of the second element.

2. The electrode assembly of claim 1, wherein the second element comprises a second electrode on a second side of the electrode assembly, wherein the second electrode comprises a planar portion adjacent to the lower peripheral edge and to the first and second lateral peripheral edges of the electrode assembly, a convex portion extending from the planar portion to a raised portion of the second electrode located in the central region of the second electrode and extending to the upper peripheral edge of the electrode assembly.

3. The electrode assembly of claim 2, wherein each of the first and second electrodes comprises an electrode for the oxygen reduction reaction.

4. The electrode assembly according to claim 2, wherein each of the first and second electrodes comprises a gas diffusion electrode (GD) with a layered structure containing an active layer and at least one support layer.

5. The electrode assembly according to claim 4, wherein the active layers of the first and second electrodes comprise a hydrophilic surface, and the support layers of the first and second electrodes comprise a hydrophobic surface.

6. The electrode assembly according to claim 4, wherein each of the first and second electrodes comprises a gas diffusion electrode (GD) with a layered structure having a built-in current collector.

7. The electrode assembly according to claim 6, in which the current collectors are in electrical contact with a busbar located in the internal chamber of the electrode assembly.

8. The electrode assembly according to claim 4, wherein the active layers of the first and second electrodes are located on the corresponding outer surfaces of the electrode assembly.

9. The electrode assembly according to claim 4, wherein the active layers of the first and second electrodes do not reach the lower peripheral edge and the first and second lateral peripheral edges of the electrode assembly.

10. The electrode assembly according to claim 9, wherein the active layers of the first electrode and the second electrode do not reach the upper peripheral edge of the electrode assembly, and wherein each of the gas diffusion electrodes with a layered structure contains a strip of electrochemically inert material located between the upper edge of the corresponding active layers and the upper peripheral edge of the electrode assembly.

11. The electrode assembly of claim 4, further comprising an insert located in the inner chamber of the electrode assembly and in contact with the respective support layers of the first and second electrodes, wherein the insert defines air flow fields through the respective support layers of the first and second electrodes.

12. The electrode assembly of claim 1, wherein the raised central region of the first electrode comprises a textured, contoured and / or roughened three-dimensional shape.

13. The electrode assembly according to claim 1, also comprising a sealing material located between the planar section of the first electrode and the surface of the second element.

14. The electrode assembly of claim 13, wherein the sealing material comprises at least one of a thermoplastic material, fluorinated ethylene propylene (FEP), polytetrafluoroethylene (PTFE), an epoxy material, or a hot-melt adhesive material.

15. The electrode assembly of claim 1, also comprising a sealing material along the lower peripheral edge and the first and second lateral peripheral edges of the electrode assembly.

16. The electrode assembly of claim 15, wherein the sealing material comprises at least one of an epoxy paint, a dosed epoxy material, an epoxy impregnation, a clamp, a collar, and an epoxy-coated tape.

17. The electrode assembly of claim 1, wherein the second side of the electrode assembly comprises a planar surface.

18. The electrode assembly of claim 17, wherein the second element comprises a support substrate consisting of an electrochemically inert material.

19. A battery containing: frame; liquid electrolyte in the housing; an anode electrode located inside the housing and at least partially immersed in a liquid electrolyte; and an electrode assembly according to any one of claims 1-18, located inside the housing and at least partially immersed in a liquid electrolyte.

20. A method for manufacturing an electrode unit, comprising: obtaining a stack of layers comprising at least one active layer and at least one support layer; forming a gas diffusion electrode with a layered structure by applying pressure and heat to a stack of layers, wherein the gas diffusion electrode with a layered structure includes a planar portion adjacent to a lower peripheral edge and to first and second lateral peripheral edges of the electrode, a convex portion extending from the planar portion to a raised portion of the electrode located in the central region and extending near the upper peripheral edge of the electrode; and coupling the gas diffusion electrode with a layered structure to the second element to hermetically attach the planar portion to the second element and form an electrode assembly having an internal chamber between the gas diffusion electrode with a layered structure and the second element.

21. The method according to claim 20, wherein the gas diffusion electrode with a layered structure comprises a first gas diffusion electrode with a layered structure, and the second element comprises a second gas diffusion electrode with a layered structure.

22. The method according to paragraph 21, also including: obtaining a second stack of layers comprising at least one active layer and at least one support layer; forming a second gas diffusion electrode with a layered structure by applying pressure and heat to the second stack of layers, wherein the second gas diffusion electrode with a layered structure includes a planar portion adjacent to the lower peripheral edge and the first and second lateral peripheral edges of the second gas diffusion electrode with a layered structure, a convex portion extending from the planar portion to a raised portion of the second gas diffusion electrode with a layered structure located in the central region and extending near the upper peripheral edge of the second gas diffusion electrode with a layered structure, and wherein connecting the first gas diffusion electrode with a layered structure to the second gas diffusion electrode with a layered structure includes forming a sealed connection between a planar section of the first gas diffusion electrode with a layered structure and a planar section of the second gas diffusion electrode with a layered structure to form an electrode assembly having an internal chamber between the first gas diffusion electrode with a layered structure and the second gas diffusion electrode with a layered structure.

23. The method according to claim 22, wherein the first and second gas diffusion electrodes with a layered structure are formed and bonded together simultaneously.

24. The method of claim 22, wherein the first and second gas diffusion electrodes with a layered structure are formed and bonded to each other by feeding a first stack of layers and a second stack of layers into a forming device and hot pressing the first stack of layers and the second stack of layers within the forming device to obtain an electrode assembly comprising a first gas diffusion electrode with a layered structure bonded to a second gas diffusion electrode with a layered structure.

25. The method according to claim 22, wherein bonding the first gas diffusion electrode with a layered structure to the second gas diffusion electrode with a layered structure comprises: feeding the first gas diffusion electrode with a layered structure and the second gas diffusion electrode with a layered structure into a mechanical pressing device; and applying mechanical pressure and heat to the planar sections of the first gas diffusion electrode with a layered structure and the second gas diffusion electrode with a layered structure using a mechanical pressing device to form the said hermetic connection between the planar section of the first gas diffusion electrode with a layered structure and the planar section of the second gas diffusion electrode with a layered structure.

26. The method of claim 21, wherein the first gas diffusion electrode with a layered structure and the second gas diffusion electrode with a layered structure are formed on a continuous sheet that is assembled and hermetically joined together along at least the first and second side faces of the electrodes.

27. A method for manufacturing an electrode unit, comprising: sealingly attaching a first gas diffusion electrode with a layered structure to one or more side walls of a support frame on a first side of the support frame in such a way that the first gas diffusion electrode with a layered structure extends along a first side of the inside of the open area of ​​the one or more side walls; and hermetically connecting the second electrode with a layered structure to one or more side walls on the second side of the support frame in such a way that the second gas diffusion electrode with a layered structure extends along the second side of the inside of the open area of ​​the one or more side walls.

28. The method according to claim 27, in which the first gas diffusion electrode with a layered structure and the second gas diffusion electrode with a layered structure are hermetically attached to the side walls under the influence of a medium with negative pressure to stimulate the penetration of the sealing material into the pores of the first and second gas diffusion electrodes with a layered structure.

29. A method for manufacturing a gas diffusion electrode with a large-area layered structure, comprising: bending the non-laminated portions of the first stack of layers and the second stack of layers to obtain mutually adhering lateral edges of the first stack of layers and the second stack of layers, wherein each stack of layers includes at least one active layer and at least one support layer; applying pressure and heat to the interlocking side edges to bind the interlocking side edges and form a seam joining the first stack of layers and the second stack of layers.

30. A method for manufacturing an electrode unit, comprising: obtaining a first stack of layers comprising at least one active layer and at least one support layer, and a second stack of layers comprising at least one active layer and at least one support layer; forming a first gas diffusion electrode with a layered structure by applying pressure and heat to a first stack of layers and a second gas diffusion electrode with a layered structure by applying pressure and heat to a second stack of layers; coupling the first gas diffusion electrode with a layered structure to the second gas diffusion electrode with a layered structure to form an electrode assembly having a spacer between the first gas diffusion electrode with a layered structure and the second gas diffusion electrode with a layered structure; and removing the spacer from the electrode assembly to form a cavity in the electrode assembly between the first gas diffusion electrode with a layered structure and the second gas diffusion electrode with a layered structure.

31. The method according to claim 30, wherein the first and second gas diffusion electrodes with a layered structure are formed and bonded together simultaneously, and the method also includes: feeding the first stack of layers, the second stack of layers and the spacer into a heat pressing device such that the spacer is positioned between the first stack of layers and the second stack of layers, wherein the heat pressing device is used to apply sufficient heat and pressure to simultaneously form and bond together the first and second gas diffusion electrodes with a layered structure.

32. The method according to paragraph 30, also including: feeding the first gas diffusion electrode with a layered structure, the second gas diffusion electrode with a layered structure and a spacer into a heat pressing device such that the spacer is located between the first gas diffusion electrode with a layered structure and the second gas diffusion electrode with a layered structure, wherein the heat pressing device is used to apply sufficient heat and pressure to bond the first gas diffusion electrode with a layered structure to the second gas diffusion electrode with a layered structure.

33. An electrode assembly comprising: a support frame having one or more side walls located around the periphery of the support frame and surrounding the interior of the open area of ​​the one or more side walls; a first gas diffusion electrode with a layered structure, hermetically attached to one or more side stacks of the support frame on a first surface of the support frame; and a second gas diffusion electrode with a layered structure, hermetically attached to one or more side walls of the support frame on the opposite surface of the support frame.

34. The electrode assembly of claim 33, wherein the first and second gas diffusion electrodes with a layered structure are hermetically attached to the corresponding first surface and opposite surface of the support frame using a first sealing material and without heat treatment.

35. The electrode assembly of claim 34, wherein one or more support walls of the support frame comprise acrylonitrile butadiene styrene (ABS), and wherein the first sealing material comprises ABS cement.

36. The electrode assembly of claim 34, wherein one or more side walls comprise three H-shaped channel structures that are configured to form at least three sides of a rectangle.

37. The electrode assembly of claim 36, wherein the rectangle comprises an open region configured to receive an insert defining at least one flow field for one or more of the first gas diffusion electrode with a layered structure and the second gas diffusion electrode with a layered structure.

38. The electrode assembly of claim 36, wherein the H-shaped channel structures are configured to receive a second sealing material.

39. The electrode assembly of claim 38, wherein the second sealing material comprises an epoxy resin.

40. The electrode assembly according to claim 33, wherein each of the first and second gas diffusion electrodes with a layered structure includes at least one active layer, at least one support layer and an integrated current collector.

41. The electrode assembly according to claim 33, wherein the first and second gas diffusion electrodes with a layered structure are hermetically attached to the corresponding first surface and opposite surface of the support frame using a first sealing material and with heat treatment.

42. A battery containing: frame; liquid electrolyte in the housing; an anode electrode located inside the housing and at least partially immersed in a liquid electrolyte; and an electrode assembly according to any one of paragraphs 33-40, located inside the housing and at least partially immersed in a liquid electrolyte.

43. An electrochemical system comprising at least one electrode assembly made by the method according to any one of paragraphs 20-32, and / or at least one electrode assembly according to any one of paragraphs 1-18 and / or 33-41.

44. The electrochemical system of claim 43, wherein the electrochemical system is a long-term energy storage system.

45. A large-scale energy storage system comprising: one or more batteries, wherein at least one of the one or more batteries comprises: at least one electrode assembly made by the method according to any one of paragraphs 20-32; and / or at least one electrode assembly according to any one of paragraphs 1-18 and / or 33-40.

46. ​​The large-scale energy storage system of claim 45, wherein the large-scale energy storage system is a long-term energy storage system.

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