Double-sealed gas diffusion electrode

Abstract

The systems and methods of various embodiments may provide a two-sided sealed gas diffusion electrode (GDE) assembly. In some embodiments, the two-sided sealed gas diffusion electrode (GDE) assembly includes active electrode layers on two opposing sides of the assembly. Various embodiments may provide architectures and / or sealing methods for the GDE assembly. In various embodiments, the GDE assembly may be for use in a device. In various embodiments, the device is a primary or secondary battery. In various embodiments, these devices may be useful for energy storage. For example, the two-sided sealed GDE assembly of various embodiments may form the cathode electrode (sometimes referred to as the air electrode) of a battery, such as a metal-air battery.

Description

[Technical field]

[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 on January 28, 2022, the entire contents of which are incorporated by reference herein for all purposes. [Background technology]

[0002] Energy storage technologies are playing an increasingly important role in the power grid. At the most basic level, these energy storage assets provide smoothing to better match generation and demand in the grid. The services performed by energy storage devices benefit the power grid over multiple timescales, from milliseconds to years. Currently, energy storage technologies exist that can support timescales from milliseconds to hours, but long-term and ultra-long-term (collectively, at least ≧8 hours) energy storage systems are needed.

[0003] Metal-air batteries are an attractive option for electrochemical energy storage due to their low cost and the abundant presence of air as a reagent for the energy storage reaction. Many of the challenges associated with the development of metal-air batteries relate to the mechanical cell architecture. Certain architectures that are suitable for small-scale storage, e.g., zinc-air hearing aid batteries, are not suitable for large-scale energy storage, such as grid-connected applications.

[0004] This "Background" section is intended to introduce various aspects of the art that may be related to embodiments of the present invention. As such, the discussion above in this section is intended to provide a framework for better understanding the present invention, and should not be construed as admissions of prior art. Summary of the Invention

[0005] The systems and methods of various embodiments can provide a useful two-sided sealed gas diffusion electrode (GDE) assembly. In various embodiments, the two-sided GDE assembly can be a GDE assembly for use in a device. In various embodiments, the device is a primary or secondary battery. In various embodiments, these devices can be useful for energy storage.

[0006] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the claims and, together with the general description set forth above and the detailed description set forth below, serve to explain the features of the claims. [Brief description of the drawings]

[0007] [Figure 1] FIG. 2 is a diagram showing a portion of a battery according to an embodiment.

[0008] [Diagram 2] FIG. 1 is a schematic diagram of a battery having a submerged oxygen reduction reaction (ORR) electrode according to various embodiments of the present disclosure.

[0009] [Figure 3A] FIG. 2 is a side cross-sectional view of an exemplary electrode assembly.

[0010] [Figure 3B] 1 is a schematic diagram of a method for manufacturing a laminated gas diffusion (GD) electrode according to various embodiments of the present disclosure.

[0011] [Figure 3C] FIG. 1 is a perspective view of a GD electrode assembly including a stacked GD electrode mounted on a support frame.

[0012] [Figure 4A] FIG. 1 is a front view of a sealed gas diffusion electrode (GDE) assembly according to an embodiment of the present disclosure. [Figure 4B] FIG. 2 is a top view of a sealed gas diffusion electrode (GDE) assembly according to an embodiment of the present disclosure. [Figure 4C] FIG. 2 is a bottom view of a sealed gas diffusion electrode (GDE) assembly according to an embodiment of the present disclosure. [Figure 4D] FIG. 1 is a side view of a sealed gas diffusion electrode (GDE) assembly according to an embodiment of the present disclosure.

[0013] [Figure 5A] FIG. 1 is a perspective view of a mold that can be used to manufacture a laminated GD electrode having a desired three-dimensional shape.

[0014] [Figure 5B] FIG. 1 is a schematic diagram of a method for manufacturing a dual-sided sealed GDE assembly using a “two-step” lamination and sealing process according to an embodiment of the present disclosure. [Figure 5C] FIG. 1 is a schematic diagram of a method for manufacturing a dual-sided sealed GDE assembly using a “two-step” lamination and sealing process according to an embodiment of the present disclosure.

[0015] [Figure 5D] FIG. 1 is a schematic diagram of a method for manufacturing a dual-sided sealed GDE assembly using an alternative two-step lamination and sealing process according to an embodiment of the present disclosure.

[0016] [Figure 6] 1 is a diagram of a GDE assembly including a sealant material located around the edges of the GDE assembly according to an embodiment of the present disclosure.

[0017] [Figure 7] FIG. 1 is a schematic diagram of a method for manufacturing a dual-sided sealed GDE assembly using a "one-step" lamination and sealing process according to an embodiment of the present disclosure.

[0018] [Figure 8] FIG. 1 is a schematic diagram of a method for manufacturing a dual-sided sealed GDE assembly using an alternative one-step lamination and sealing process according to an embodiment of the present disclosure.

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

[0020] [Figure 10] FIG. 13 is a schematic diagram of an alternative one-step lamination and encapsulation process that can be used to simultaneously fabricate multiple GDE assemblies according to another embodiment of the present disclosure.

[0021] [Figure 11A] 1 is a cross-sectional view of an exemplary GDE assembly having a contoured outer surface in accordance with an embodiment of the present disclosure. [Figure 11B] 1 is a cross-sectional view of an exemplary GDE assembly having a contoured outer surface in accordance with an embodiment of the present disclosure. [Figure 11C] 1 is a cross-sectional view of an exemplary GDE assembly having a contoured outer surface in accordance with an embodiment of the present disclosure.

[0022] [Figure 12A] 1A-1D are diagrams of a reduced active area GDE assembly and a method of manufacturing the GDE assembly according to an embodiment of the present disclosure. [Figure 12B] 1A-1D are diagrams of a reduced active area GDE assembly and a method of manufacturing the GDE assembly according to an embodiment of the present disclosure. [Figure 12C] 1A-1D are diagrams of a reduced active area GDE assembly and a method of manufacturing the GDE assembly according to an embodiment of the present disclosure.

[0023] [Figure 13A] 1A-1C are diagrams of a reduced active area GDE assembly and a method of manufacturing the GDE assembly according to another embodiment of the present disclosure. [Figure 13B] 1A-1C are diagrams of a reduced active area GDE assembly and a method of manufacturing the GDE assembly according to another embodiment of the present disclosure. [Figure 13C] 1A-1C are diagrams of a reduced active area GDE assembly and a method of manufacturing the GDE assembly according to another embodiment of the present disclosure.

[0024] [Figure 14A] FIG. 2 is a top view of a GDE assembly according to another embodiment of the present disclosure. [Figure 14B] FIG. 2 is a side view of a GDE assembly according to another embodiment of the present disclosure.

[0025] [Figure 15A] FIG. 2 is a front view of a two-sided sealed GDE assembly including an insert within the internal chamber of the GDE assembly according to an embodiment of the present disclosure. [Figure 15B] FIG. 2 is a top view of a two-sided seal GDE assembly including an insert within an internal chamber of the GDE assembly according to an embodiment of the present disclosure.

[0026] [Figure 16A] 11A-11D illustrate a method for manufacturing a dual-sided sealed GDE assembly having an internal conductive member according to yet another embodiment of the present disclosure. [Figure 16B] 11A-11D illustrate a method for manufacturing a dual-sided sealed GDE assembly having an internal conductive member according to yet another embodiment of the present disclosure. [Figure 16C] 11A-11D illustrate a method for manufacturing a dual-sided sealed GDE assembly having an internal conductive member according to yet another embodiment of the present disclosure.

[0027] [Figure 17A] 1A-1C illustrate a method for manufacturing a dual-sided sealed GDE assembly having a pair of planar GD electrodes attached to a support frame according to an embodiment of the present disclosure. [Figure 17B] 1A-1C illustrate a method for manufacturing a dual-sided sealed GDE assembly having a pair of planar GD electrodes attached to a support frame according to an embodiment of the present disclosure.

[0028] [Figure 18A] FIG. 1 is a side view of a dual-sided sealed GDE assembly having a pair of planar GD electrodes mounted on a support frame according to an embodiment of the present disclosure.

[0029] [Figure 18B] FIG. 1 is a side view of a dual-sided sealed GDE assembly having a pair of planar GD electrodes mounted on a support frame according to another embodiment of the present disclosure. [Figure 18C] FIG. 1 is a side view of a dual-sided sealed GDE assembly having a pair of planar GD electrodes mounted on a support frame according to another embodiment of the present disclosure.

[0030] [Figure 19A] A method for manufacturing a dual-sided sealed GDE assembly according to the embodiment shown in Figures 18B and 18C is shown. [Figure 19B] A method for manufacturing a dual-sided sealed GDE assembly according to the embodiment shown in Figures 18B and 18C is shown.

[0031] [Figure 20A] 1 illustrates a method for manufacturing a large area stacked GD electrode using interlocking seams according to an embodiment of the present disclosure. [Figure 20B] 1 illustrates a method for manufacturing a large area stacked GD electrode using interlocking seams according to an embodiment of the present disclosure.

[0032] [Figure 21A] 1 illustrates the manufacturing process of a dual-sealed GDE assembly using a "flat press" process. [Figure 21B] 1 illustrates the manufacturing process of a dual-sealed GDE assembly using a "flat press" process. [Figure 21C] 1 illustrates the manufacturing process of a dual-sealed GDE assembly using a "flat press" process. [Figure 21D] 1 illustrates the manufacturing process of a dual-sealed GDE assembly using a "flat press" process. [Figure 21E] 1 illustrates the manufacturing process of a dual-sealed GDE assembly using a "flat press" process.

[0033] [Figure 22]1A-1D illustrate various exemplary systems in which one or more aspects of various embodiments may be used as part of a bulk energy storage system. [Figure 23] 1A-1D illustrate various exemplary systems in which one or more aspects of various embodiments may be used as part of a bulk energy storage system. [Figure 24] 1A-1D illustrate various exemplary systems in which one or more aspects of various embodiments may be used as part of a bulk energy storage system. [Diagram 25] 1A-1D illustrate various exemplary systems in which one or more aspects of various embodiments may be used as part of a bulk energy storage system. [Figure 26] 1A-1D illustrate various exemplary systems in which one or more aspects of various embodiments may be used as part of a bulk energy storage system. [Figure 27] 1A-1D illustrate various exemplary systems in which one or more aspects of various embodiments may be used as part of a bulk energy storage system. [Figure 28] 1A-1D illustrate various exemplary systems in which one or more aspects of various embodiments may be used as part of a bulk energy storage system. [Figure 29] 1A-1D illustrate various exemplary systems in which one or more aspects of various embodiments may be used as part of a bulk energy storage system. [Diagram 30] 1A-1D illustrate various exemplary systems in which one or more aspects of various embodiments may be used as part of a bulk energy storage system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] Various embodiments will be described in detail with reference to the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. References to specific examples and implementations are for illustrative purposes only 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 such embodiments, but rather to enable one of ordinary skill in the art to make and use the invention.

[0035] As used herein, unless otherwise specified, room temperature is 25° C. and standard temperature and pressure are 25° C. and 1 atmosphere. Unless expressly stated otherwise, all tests, test results, physical properties, and values ​​that are temperature dependent, pressure dependent, or both, are provided at standard ambient temperature and pressure.

[0036] In general, the term "about," as used herein, unless otherwise specified, is meant to encompass a variation or range of ±10%, the experimental or instrumental error associated with obtaining the stated value, preferably whichever is greater.

[0037] As used herein, unless otherwise stated, recitation of ranges of values ​​herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise stated herein, each individual value within a range is incorporated herein as if it were individually recited herein.

[0038] The following examples are provided to illustrate various embodiments of the present systems and methods of the present invention. Such examples are intended to be illustrative and may be prophetic, and should not be considered limiting or in any way limit the scope of the present invention.

[0039] It should be noted that it is not necessary to provide or express the theory underlying the novel and innovative process, material, performance, or other beneficial features and characteristics that are the subject of or associated with embodiments of the present invention. Nevertheless, various theories are provided herein to further advance the art in the field. The theories presented herein are not intended to limit, restrict, or narrow in any way the scope of protection afforded to the claimed invention unless expressly stated otherwise. Such theories may not be necessary or practiced to utilize the present invention. Furthermore, it is understood that the present invention may be coupled with new and previously unknown theories to explain the function-characteristics of embodiments of the methods, articles, materials, devices, and systems of the present invention. Such subsequently developed theories shall not limit the scope of protection afforded to the present invention.

[0040] The various embodiments of the systems, facilities, techniques, methods, activities, and operations shown herein can be used in various other activities and other fields in addition to those shown herein. In addition, such embodiments can be used, for example, with other facilities or activities that may be developed in the future and with existing facilities or activities that may be partially modified based on the teachings herein. Furthermore, the various embodiments and examples shown herein can be used with each other, in whole or in part, and in various different combinations. Thus, for example, configurations provided in various embodiments herein can be used with each other. For example, elements of an embodiment having A, A', and B, and elements of an embodiment having A'', C, and D can be used with each other in various combinations, such as A, C, D, and A, A'', C, D, in accordance with the teachings herein. Thus, the scope of protection given to the present invention should not be limited to the specific embodiments, configurations, or arrangements shown in the specific embodiments, examples, or embodiments of the specific figures.

[0041] Embodiments of the present invention include devices, systems, and methods for long-term and ultra-long-term low-cost energy storage. As used herein, "long-term" and "ultra-long-term" and similar such terms shall be given the broadest possible meaning unless expressly stated otherwise and shall include energy storage periods of 8 hours or longer, such as 8 hours of energy storage period, energy storage periods ranging from 8 hours to 20 hours, 20 hours of energy storage period, energy storage periods ranging from 20 hours to 24 hours, 24 hours of energy storage period, energy storage periods ranging from 24 hours to 1 week, energy storage periods ranging from 1 week to 1 year (e.g., from days to weeks to months, etc.), and shall include LODES systems. Additionally, the terms "long-term" and "ultra-long-term", "energy storage cell" including "electrochemical cell", and similar such terms shall be given the broadest possible interpretation unless expressly stated otherwise and shall include electrochemical cells that may be configured to store energy over time ranges of days, weeks, or seasons.

[0042] Generally, in an embodiment, the long-term energy storage cell may be a long-term electrochemical cell. Generally, this long-term electrochemical cell can store electricity generated in the power generation system when: (i) the power source or fuel for the generation is available, abundant, cheap, and combinations and variations thereof; (ii) the power needs or demands of the grid, customer, or other users are less than the amount of electricity generated by the power generation system, the price paid to provide such electricity to the grid, customer, or other users is below the economically efficient point for generating such electricity (e.g., the generation cost exceeds the market price of electricity), and combinations and variations thereof; and (iii) combinations and variations of (i) and (ii) and other reasons. This electricity stored in the long-term electrochemical cell can then be distributed to the grid, customer, or other users when it is economical or otherwise needed. For example, the electrochemical cell may be configured to store energy generated by solar cells during summer months when sunlight is abundant and solar power generation exceeds power grid needs, and to discharge the stored energy during winter months when sunlight may be insufficient to meet power grid needs.

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

[0044] In various embodiments, the electrolyte 140 is a liquid. In various embodiments, the anode 110 is solid and the electrolyte 140 is excluded from the anode. In various other embodiments, the anode 110 is porous and the anode 110 is geometrically interspersed with the electrolyte 140 to increase the interfacial surface area for the reaction. In various embodiments, the cathode 120 is porous and the anode 110 is geometrically interspersed with the electrolyte to increase the interfacial surface area for the reaction. In various embodiments, the cathode 120 is located at the interface between the electrolyte and the gaseous headspace 105. In various embodiments, the gaseous headspace is sealed within the housing 170. In various other embodiments, the housing 170 is not sealed and the gaseous headspace is an open system that can freely exchange materials with the environment.

[0045] The anode 110 may be formed of a metal or metal alloy, such as lithium (L), sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), silicon (Si), aluminum (Al), zinc (Zn), or iron (Fe); or an alloy consisting essentially of one or more of the above forgoing metal elements capable of undergoing an oxidation reaction for discharge, such as an aluminum alloy or an iron alloy (e.g., FeAl, FeZn, FeMg, etc.). Thus, the anode 110 may be referred to herein as a metal electrode. In certain embodiments, the battery is rechargeable and the metal electrode undergoes a reduction reaction when the battery is charged. The anode 110 may be a solid, such as a dense or porous solid, or a mesh or foam, or a particle or collection of particles, or may be a slurry, ink, suspension, or paste disposed within the housing 170. In various embodiments, the composition of the anode 110 may be selected such that the anode 110 and much of the liquid electrolyte 140 are not mixed. For example, the anode 110 may be a metal electrode that may be a bulk solid. As another example, the anode 110 may be a collection of particles, such as small or bulky particles in a suspension, where the suspension is not so buoyant that the suspension escapes into the electrolyte. As another example, the anode 110 may be formed from particles that are not buoyant in the electrolyte.

[0046] The cathode electrode (sometimes called the air electrode) 120 supports a reaction with oxygen on the positive electrode. The cathode 120 may be a so-called gas diffusion electrode (GDE), which is a solid and located at the interface between the gas headspace 105 and the electrolyte 140. During the discharge process, the cathode 120 supports the reduction of oxygen from the gaseous headspace 170, the so-called oxygen reduction reaction (ORR). In certain embodiments, the battery 100 is rechargeable and the reverse reaction occurs, during which the cathode 120 supports the evolution of oxygen from the battery, the so-called oxygen evolution reaction (OER). The 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 the ORR and the battery is a primary (discharge only) metal-air battery. In certain embodiments, the cathode 120 is a single electrode that supports both the ORR (discharge reaction) and the OER (charge reaction) and the metal-air battery is rechargeable (secondary battery). The cathode 120 may be a single air electrode "bifunctional electrode" (operating in both OER and ORR modes) or a combination of two electrodes "dual electrode" (one electrode configured to operate in OER mode and another electrode configured to operate in ORR mode).

[0048] In various embodiments, the electrolyte 140 is a liquid. In certain embodiments, the electrolyte 140 is an aqueous solution, a non-aqueous solution, or a combination thereof. In various embodiments, the electrolyte 140 is an aqueous solution that may be acidic (low pH), neutral (medium pH), or basic (high pH, ​​also referred to as alkaline or caustic). In certain embodiments, the liquid electrolyte 140 may include electropositive elements such as Li, K, Na, or combinations thereof. In some embodiments, the liquid electrolyte may be basic, i.e., have 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, the electrolyte 140 may include a 6 M (moles per liter) concentration of potassium hydroxide (KOH). In certain embodiments, the electrolyte 140 may include a combination of components such as 5.5 M potassium hydroxide (KOH) and 0.5 M lithium hydroxide (LiOH). In certain embodiments, the electrolyte 140 may include a 6 M (moles per liter) concentration of sodium hydroxide (NaOH). In a particular embodiment, the electrolyte 140 may include sodium hydroxide (NaOH) at a concentration of 5M (moles per liter) and potassium hydroxide (KOH) at 1M.

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

[0050] Thus, oxygen delivery to a metal-air cell requires gas handling and maintenance of a three-phase point. The three-phase point or boundary represents the area where the solid, electrolyte, and gas all come into contact. This is where the heterogeneous reaction actually occurs. In certain embodiments, referred to as the "normal air-breathing" configuration, the cathode 120 is mechanically positioned at the gas-liquid interface to promote and maintain the three-phase boundary. The cathode 120 may be positioned vertically, horizontally, or at any intermediate angle relative to gravity while still maintaining the "normal air-breathing" configuration. In these "normal air-breathing" configurations, the gas phase is at atmospheric pressure (i.e., not pressurized beyond the action of 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., a cathode 120 made up 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 periodically.

[0052] The first cathode may be configured to operate in ORR mode and may be referred to as an "ORR electrode." The first cathode (i.e., ORR electrode) may be divided into two parts: a first part having a hydrophilic surface and a second part having a hydrophobic surface. For example, the hydrophobic surface may have a polytetrafluoroethylene (PTFE) (e.g., Teflon®) hydrophobic surface. For example, the second part may be a polytetrafluoroethylene (PTFE) and a high surface area carbon microporous layer (MPL), and the first part may be carbon fiber partially coated with PTFE. As another example, the second part may be an MPL of PTFE and carbon black, and the first part may be about 33% by weight PTFE. As a further example, the second part may be an MPL of 23% by weight PTFE and 77% by weight carbon black, and the first part may be a low loading MPL.

[0053] The second cathode may be configured to operate in an OER mode and may be referred to as an "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 (T), steel, etc., coated with nickel (Ni). An electrolyte (e.g., electrolyte 140) is disposed between the three electrodes. The electrolyte may wet one or more of the three electrodes.

[0054] In certain embodiments, it may be advantageous to immerse the ORR electrodes below the liquid level (e.g., the gas-liquid interface) of the cell. In these embodiments, referred to as "reverse air-breathing" configurations, the three-phase boundary occurs by air (oxygen) delivery to the ORR electrodes, which are located below the liquid level. This has several advantages. First, the ORR electrodes are normally wetted, reducing the risk of drying out and salt crust formation on the electrodes. Second, leakage from the electrodes can only be inside the cell, with no leakage of electrolyte to the external environment. Third, the depth of the cell can be quite large (height dimension of the primary housing).

[0055] FIG. 2 illustrates an exemplary embodiment of a battery 200 having a submerged ORR electrode 203. The battery 200 includes a liquid electrolyte solution 140 located within a primary housing 170, at least one anode electrode 110, and at least one ORR electrode 203. The battery 200 also includes at least one OER electrode 205 within the primary housing 170. The electrodes 110, 203, and 205 may each be partially or completely submerged below a liquid level 201 of the electrolyte solution 140. An outer portion of each of the submerged ORR electrodes 203 may be in contact with the electrolyte 140, and the electrolyte may partially infiltrate within the ORR electrode 203. An inner portion of each of the ORR electrodes 203 may include air (oxygen) or may be at least substantially free of the 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 ORR electrodes 203 may support multiple three-phase points or three-phase boundaries within the ORR electrode 203.

[0056] One or more air lines 207 may provide air to the interior portions of each of the ORR electrodes 203. The air lines 207 may provide air from the headspace 105 of the primary housing 170, from the external environment, and / or from a blower or similar mechanism that may actively provide air to the ORR electrode(s) 203. In some embodiments, the air provided to the ORR electrode(s) 203 may be pressurized above atmospheric pressure. In some embodiments, the air may be circulated through each of the ORR electrodes 203 and may exit each ORR electrode 203 through a separate outlet air line or conduit. Alternatively, or additionally, the air may be exhausted from the ORR electrodes 203 to the liquid electrolyte 140.

[0057] As shown in FIG. 2, the battery 200 may have a repeating anode-cathode-anode-cathode arrangement, where the number of repeat units, dimensions, positions and orientations of the anode and cathode electrodes 110, 203 and / or 205 may vary in various embodiments.

[0058] FIG. 3A is a side cross-sectional view of an exemplary electrode assembly 300. In operation, the electrode assembly 300 may be partially or completely submerged below the electrolyte level of a battery, such as the battery 200 shown in FIG. 2. The electrode assembly 300 includes an electrode 203, such as an ORR electrode, constructed of a laminated sheet or film attached to a support frame 305. The support frame 305 may include one or more open areas or channels 307 that may provide a flow field 309 for air or oxygen gas. One or more inlet conduits (not shown in FIG. 3A) may provide gas (e.g., air) to the flow field 309, where the gas may be directed to and across the electrode 203. The support frame 305 may be constructed of plastic (e.g., polypropylene, HDPE, acrylonitrile butadiene styrene (ABS), etc.) and / or metal (e.g., steel, nickel, etc.) materials. The channels 307 of the flow field 309 may be configured to direct the gas flow through the flow field 309 and across the electrode 203. The channels 307 may be in the shape of a parallel, interdigitated, serpentine, 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 exit conduits (not shown in FIG. 3A ) may direct the gas flow from the flow field 309 out of the electrode assembly 300.

[0059] The electrode 203 may include a laminate structure including at least one first layer 311 (sometimes referred to as an "active" layer) adjacent to the electrolyte and at least one second layer 313 (sometimes referred to as a "backing" layer) adjacent to the flow field 309. The active layer 311 may include a hydrophilic surface and the backing layer 313 may include a hydrophobic surface. The backing layer 313 may be a gas diffusion layer (GDL). A current collector may be embedded in the laminate structure of the electrode 203. The electrode 203 as shown in FIG. 3A may be referred to as a gas diffusion (GD) electrode 203.

[0060] FIG. 3B shows a schematic diagram of a method for fabricating a planar laminated GD electrode 203 according to various embodiments. A number of individual sheets or films may be arranged to provide a layer stack 320. The layer stack 320 may include at least one active layer 311 and at least one backing layer 313. As shown in FIG. 3B, a current collector 315 may be located within the stack 320, for example, between a pair of backing layers 313. Alternatively, the current collector 315 may be located between the active layer 311 and the backing layer 313, or between two active layers 311. In various embodiments, the active layer 311 may be located on the outer surface of the layer stack 320.

[0061] In some embodiments, the active layer(s) 311 and the backing layer(s) 313 may each include a carbon-based material and may further include additional materials such as binder(s) and other functional additives such as PTFE. The current collector 315 may include a 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 contemplated scope of the disclosure. The current collector 315 may have a porous structure, examples of which include wire mesh, metal foam, porous sintered metal sheet, metal fiber product, punched metal sheet, etc.

[0062] Referring again to FIG. 3B, the layer stack 320 may be subjected to mechanical pressure at elevated temperature to bond the individual layers to form the laminated GD electrode 203. In various embodiments, the laminated GD electrode 203 may be formed using a hot pressing process. During the hot pressing process, the layer stack 320 is compressed to a pressure of at least about 400 psi while being heated to a temperature of at least about 300° C. The current collector 315 may be embedded within the laminated GD electrode 203. A portion of the current collector 315 may optionally extend beyond the edge of the laminate to facilitate electrical contact to the current collector 315. The active layer 311 may be exposed on the outer surface of the laminated GD electrode 203.

[0063] FIG. 3C is a perspective view of a GD electrode assembly 300 including a planar laminate GD electrode 203 attached to a support frame 305. As shown in FIG. 3C, the assembly 300 may be assembled by fastening a laminate GD electrode 203 as shown in FIG. 3B to a support frame 305. The support frame may be constructed 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. Inlet and outlet conduits 316 and 317 may provide gas (e.g., air) flow to and from the flow field. Potting material 318 may be provided on portions of the assembly 300 to help seal the interior of the assembly 300 from wetting with the liquid electrolyte. In some embodiments, the potting material 308 may include a two-part epoxy that may harden during a cure time at an elevated temperature. In some cases, the cure time may be 10 hours or more, such as 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 backing layer 313 of the GD electrode 203 may be pressed against the flow field. An electrical conductor 319 (e.g., a wire) may be electrically connected to the current collector 315 of the GD electrode 300.

[0064] Various embodiments of the present disclosure relate to electrodes, such as an oxygen reduction reaction (ORR) electrode 203, electrode assemblies, and methods of making electrodes and electrode assemblies. The 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, the two-sided sealed gas diffusion electrode (GDE) assembly includes active electrode layers on two opposing sides of the assembly. Various embodiments may provide architectures and / or sealing methods for the GDE assembly. In various embodiments, the GDE assembly may be for use in a device. In various embodiments, the device is a primary or secondary battery. In various embodiments, these devices may be useful for energy storage. For example, the two-sided sealed GDE assembly of various embodiments may form the cathode electrode (sometimes called the air electrode) 120 of a battery.

[0065] 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 disclosure. The GDE assembly 400 according to various embodiments may be formed by two laminated GD electrodes 203 joined together to form a pouch-like or pocket-like structure having an open interior chamber 401, as described above. In some embodiments, a continuous sheet or film structure having a pair of laminated GD electrodes 203 thereon may be assembled (e.g., folded onto itself) and sealed around the edges to form the pouch-like or pocket-like GDE assembly 400. The GDE assembly 400 may be immersed in the electrolyte bath of a metal-air battery such that the interior chamber 401 is hydrodynamically isolated from the external electrolyte. Air may be present within the interior chamber 401 of the assembly 400 and may react with the electrolyte to controllably wet the exterior surface of the electrode material. In various embodiments, the electrode(s) of the GDE assembly 400 support the oxygen reduction reaction (ORR) and are also referred to as "ORR electrodes."

[0066] 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 "rear" side 403. The GDE assembly 400 may have a first perimeter 411, a second perimeter 406 opposite the first perimeter 411, a third perimeter 407, and a fourth perimeter 408 opposite the third perimeter 407. For convenience, the first perimeter 411 may be referred to as the “top” perimeter of the GDE assembly 400, the second perimeter 406 may be referred to as the “bottom” perimeter of the GDE assembly 400, and the third and fourth perimeters 407 and 407 may be referred to as the “side” perimeters of the GDE assembly 400.

[0067] As shown in FIGS. 4A-4D , the GDE assembly 400 may have a substantially planar, flat portion 405 having a shape resembling the letter “U” that extends continuously adjacent the side peripheries 407 and 408 and the bottom periphery 406 of the DE assembly 400. The front 403 and rear 404 faces of the GDE assembly 400 may also include convex portions 409 that are angled or curved outwardly from the flat portion 405 and extend from the flat portion 405 toward a central region 410 of the GDE assembly 400. In some embodiments, the central region 410 of the GDE assembly 400 may include substantially planar flat surfaces on the front 403 and rear 404 faces that are raised relative to the substantially planar flat portion 405 that extends around the periphery of the GDE assembly 400. The raised central region 410 on the front 403 and rear 404 faces of the GDE assembly 400 may extend to the top periphery 411 of the GDE assembly 400. The top periphery 411 of the GDE assembly 400 may define an opening to the interior chamber 401 of the GDE assembly 400. In embodiments where the GDE assembly 400 is formed by a pair of stacked GD electrodes 203a, 203b, the respective GD electrodes 203a, 203b may contact each other along a substantially planar flat portion 405 that extends around the periphery of the GDE assembly 400. The respective stacked GD electrodes 203a and 203b may be joined along the flat planar portion 405 to form a liquid-tight seal. In some embodiments, described in more detail below, a sealant material may be located between the stacked GD electrode pairs 203a and 203b, along the substantially planar flat portion 405, and / or along the side periphery 407 and 408 and bottom periphery 406 of the GDE assembly 400. The outer surfaces on the front 403 and rear 404 of the GDE assembly 400 may each include an active electrode layer as described above. The active electrode layers may comprise a hydrophilic surface. The interior surface of the GDE assembly 400 that encloses and forms the exterior surface of the interior chamber 401 may include backing layers as described above. The backing layers may each comprise a hydrophobic surface. Current collectors may be embedded between the active electrode layers on the exterior surface of the GDE assembly and the backing layers that form the surfaces of the interior chamber 401 of the GDE assembly 400.Thus, the GDE assembly 400 may include a pair of functional electrodes, such as stacked GDE electrodes, on two opposing sides 403, 404 (i.e., faces) of the GDE assembly 400, and may be referred to as a "two-sided" sealed GDE assembly 400.

[0068] A dual-sealed GDE assembly 400 as shown in Figures 4A-4D can be advantageous in terms of manufacturability and cost-effectiveness. In various embodiments described in more detail below, the dual-sealed GDE assembly 400 may be manufactured using a few simple steps, possibly including a one-stage process involving lamination of a multi-layer stack and forming one or more electrodes simultaneously with the formation of a sealed housing for the GDE assembly 400. This avoids the complex processes used to manufacture the electrode assembly 300 as shown in Figure 3C, which often require complex jigs, skilled operators, and long curing times to manufacture and adequately seal the assembly 300.

[0069] 5A is a perspective view of a mold 500 that may be used to fabricate a laminated GD electrode 203 having a desired three-dimensional shape. The mold 500 may be used to form a laminated GD electrode 203 having a three-dimensional shape with flat flange-like portions that extend around the GD electrode 203 adjacent the bottom and side peripheral edges of the electrode, and convex portions that extend between the flange-like portions and a raised portion located in a central region of the GD electrode 203 that extends to the top peripheral edge. In various embodiments, a pair of such GD electrodes 203 having a three-dimensional shape may be joined and sealed along their respective flange-like portions to provide a two-sided sealed GDE assembly 400, as shown in FIGS. 4A-4D.

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

[0071] The layer stack 320 may then be mechanically pressed between the first piece 500a and the second piece 500b of the mold 500, as shown generally by the arrows 503 in FIG. 5B. In some embodiments, the layer stack 320 may be pressed using a hot pressing process. The heat source 501 may be, for example, an inductive heat source, an indirect resistance heat source, and / or a direct resistance heat source, and may heat the layer stack 320 to an elevated temperature during the hot pressing process. In some embodiments, during the hot pressing process, the layer stack 320 is compressed to a pressure of at least about 400 psi while being heated to a temperature of at least about 300° C. The hot pressing process may produce a laminated ORR electrode 203 having a desired three-dimensional shape as described above. Multiple layer stacks 320 may be pressed in the mold 500 to produce multiple laminated GD electrodes 203, as shown in FIG. 5B. Each laminated GD electrode 203 may have the same or substantially the same three-dimensional shape.

[0072] Referring to FIG. 5C, in a second step of the two-step lamination and sealing process, the pair of laminated GD electrodes 203a and 203b may be placed in a mechanical press 505. Each of the laminated GD electrodes 203a and 203b may have the same or substantially the same three-dimensional shape and may be formed using the process described in FIG. 5B above. The laminated GD electrodes 203a and 203b may be placed in the mechanical press 505 such that flat flange-like portions extending around the periphery of the GD electrodes 203a and 203b adjacent the bottom and lateral peripheries of the GD electrodes 203a and 203b contact each other. The convex portions of the GD electrodes 203a and 203b extending from the flat flange-like portions of the GD electrodes 203a and 203b face away from each other, resulting in a void region 506 between the respective GD electrodes 203a and 203b in the mechanical press 505.

[0073] The pair of GD electrodes 203a and 203b may then be mechanically pressed together between the pair of heated press plates 505a and 505b of the mechanical press apparatus 500 as shown diagrammatically by arrow 503 in FIG. 5C. The heated press plates 505a and 505b may mechanically press the GD electrodes 203a and 203b along flat flange-like portions that extend around the periphery of the GD electrodes 203a and 203b to join the GD electrodes 203a, 203b and provide a continuous seal around the bottom and side surfaces of the GD electrodes 203a and 203b. A heat source 509 may heat the press plates 505a and 505b during the pressing process. In some embodiments, the press 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. The pressing process can produce a two-sided sealed GDE assembly 400 that includes an interior chamber 401, as shown in Figures 4A-4D.

[0074] In some embodiments, the two-sided sealed GDE assembly 400 may be manufactured using a "three-stage" process that includes an initial lamination step to form the GD electrodes 203a and 203b, such as by a hot pressing process as shown in Figure 5B, followed by an initial bonding step to bond the pair of GD electrodes 203a and 203b into the shape of the final GDE assembly 400, followed by a high temperature mechanical pressing step to form a permanent bond around the bottom and side surfaces of the GD electrodes 203a and 203b and provide a continuous seal, as shown in Figure 7C. The initial bonding step may include a relatively low pressure and / or low temperature bonding step in some embodiments.

[0075] FIG. 5D is a schematic diagram of an alternative two-step lamination and sealing process according to an embodiment of the present disclosure. Referring to FIG. 5D, a sealant material 510 may be provided between the GD electrodes 203a and 203b prior to the mechanical pressing step. The sealant material 510 may be provided between the GD electrodes 203a and 203b along a flat flange-like portion that extends around the periphery of the GD electrodes 203a and 203b. The sealant material 510 may include, for example, hot melt adhesive materials such as fluorinated ethylene propylene (FEP), polytetrafluoroethylene (PTFE), or other thermoplastic materials, epoxy materials, and / or ethylene vinyl acetate. Other suitable sealant materials are within the contemplated scope of the disclosure. The sealant material 510 may function similarly to a "gasket" in the final post-press product and may help improve sealing of the two-sided sealing GDE assembly 400 to minimize or prevent liquid wetting into the interior chamber 401 when the GDE assembly 400 is immersed in electrolyte. In some embodiments, the sealant material 510 may be electrically insulating to provide electrical insulation between each of the electrodes 203 a and 203 b of the dual-sided sealed GDE assembly 400 .

[0076] Alternatively, or in addition, an outer seal may be provided on the outer surface of the GDE assembly 400. FIG. 6 shows the GDE assembly 400 including a sealant material 600 located around the bottom perimeter 406 and the side perimeters 407 and 408 of the GDE assembly 400. For example, the sealant material 600 may include an epoxy paint, an epoxy dose, or an epoxy dip seal that may be provided around the edges of the GDE assembly 400 to provide additional integrity to the seal. In some embodiments, the sealant material 600 may include a mechanical seal, such as one or more clamps, clips, or tapes that may be provided around the outer edges of the GDE assembly 400. In some embodiments, the sealant material 600 may include an epoxy lining tape that adheres around the edges of the GDE assembly 400 and "doses" the edge seal with additional epoxy to improve seal integrity.

[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 stacked GD electrodes 203a, 203b together to provide the interior chamber 401 of the GDE assembly 400 with adequate hydraulic isolation from the surrounding liquid electrolyte.

[0078] FIG. 7 illustrates a schematic of a method for manufacturing a two-sided sealed GDE assembly 400 using a "one-step" lamination and sealing process. With reference to FIG. 7, a pair of layer stacks 320a and 320b may be placed into a cavity of a mold 700. In various embodiments, as shown in FIG. 3B, each of the layer stacks 320a and 320b may include at least one active electrode layer 311 and at least one backing layer 313. Each of the layer stacks 320a and 320b may also include a current collector 315. The mold 700 may include a three-part 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 piece 700a and the second piece 700b may be identical or substantially identical to one another, and the concave surfaces of the first and second pieces 700a and 700b may be positioned to face one another within the mold 700 as shown in FIG. 7. 7 embodiment, mold 700 may include a third piece 700c located between first piece 700a and second piece 700b. The third piece 700a may include a convex cross-sectional shape including a first convex surface 702 that complements and faces a concave surface of the first piece 700a of mold 700, and a second convex surface 704 that complements and faces a concave surface of the second piece 700b of mold 700.

[0079] As shown in FIG. 7, the first layer stack 320a may be placed between the first piece 700a and the third piece 700a in the mold 700, and the second layer stack 320b may be placed between the second piece 700b and the third piece 700c in the mold 700. Portions of the layer stacks 320a and 320b along the bottom and two lateral sides of each layer stack 320a and 320b may extend beyond the periphery of the third piece 700c of the mold 700. The first layer stack 320a and the second layer stack 320b may be arranged such that the backing layer 313 on the outer surface of each layer stack 320a and 320b faces the third piece 700c, and the active layer 311 located on the outer surface of each layer stack 320a and 320b faces the first piece 700a or the second piece 700b of the mold 700.

[0080] Thereafter, as shown generally by arrow 503 in FIG. 7, the first layer stack 320a may be mechanically pressed between a surface 702 of the first and third pieces 700a and 700c of the mold 700, while the second layer stack 320b may be mechanically pressed between a surface 704 of the second and third pieces 700b and 700c of the mold 700. The peripheral portions of the first and second layer stacks 320a and 320b along the bottom and two lateral sides of the layer stacks 320a and 320b may contact each other and may be mechanically pressed between the first and second pieces 700a and 700b of the mold 700 to form the substantially planar flat portion 405 of the completed GDE assembly 400 (see FIGS. 4A-4D). In some embodiments, the first and second layer stacks 320a and 320b may be pressed using a hot pressing process. The heat source 701 may be, for example, an induction heat source, an indirect resistance heat source, and / or a direct resistance heat source, and may heat the layer stacks 320a and 320b to an elevated temperature during the hot pressing process. In some embodiments, during the hot pressing process, the layer stacks 320a and 320b are simultaneously heated to a temperature of at least about 300° C. and compressed to a pressure of at least about 400 psi. The hot pressing process may simultaneously laminate each of the layer stacks 320a and 320b to produce the stacked GD electrode pair 203a and 203b having a desired three-dimensional shape, and may simultaneously bond the stacked GD electrode pair 203a and 203b to provide a continuous seal surrounding the bottom and side surfaces of the GD electrodes 203a and 203b. Thus, the double-sealed GDE assembly 400 may be fabricated using a single, one-step lamination and sealing process. The double-sealed GDE assembly 400 may be removed from the mold 700, as shown on the right side of FIG. 7.

[0081] FIG. 8 illustrates a schematic of a method for manufacturing a GDE assembly 400 using an alternative one-step lamination and sealing process according to an embodiment of the present disclosure. Referring to FIG. 8, prior to lamination and sealing using a mold 700, a sealant material 510 may be provided between the first layer stack 320a and the second layer stack 320b. The sealant material 510 may be provided between the layer stacks 320a and 320b near the bottom and side peripheral edges of the layer stacks 320a and 320b where the layer stacks 320a and 320b contact each other. The sealant material 510 may include any suitable sealant material, such as the sealant material described above with reference to FIG. 5D. The sealant material 510 may help improve sealing of the two-sided sealing GDE assembly 400 to minimize or prevent liquid wetting into the interior chamber 401 when the GDE assembly 400 is immersed in an electrolyte. In some embodiments, the sealant material 510 may be electrically insulating to provide electrical insulation between the respective electrodes 203a and 203b of the dual-sealed GDE assembly 400. Alternatively, or in addition, an outer seal may be provided on the outer surface of the GDE assembly 400 along the edges between the electrodes 203a and 203b following the lamination and sealing step in mold 700, as described above with reference to FIG.

[0082] FIG. 9 is a cross-sectional side view of the mold 700 as shown in FIGS. 7 and 8 taken along line A-A′ in FIG. 8. FIG. 9 illustrates an alternative one-step lamination and sealing process according to an embodiment of the present disclosure. In the alternative one-step lamination and sealing process of FIG. 9, a single continuous layer stack 320 may be placed in the mold. The single continuous layer stack 320 may be folded over such that a first portion of the continuous layer stack 320 is located between the first piece 700a and the third piece 700c of the mold 700 and a second portion of the continuous layer stack 320 is located between the second piece 700b and the third piece 700c of the mold 700, as shown in FIG. 9. The portion of the continuous layer stack 320 adjacent the side edge of the continuous layer stack 320 may extend beyond the periphery of the third piece 700c of the mold 700. As shown in FIG. 9, the portion of the continuous layer stack 320, including the fold 901 of the continuous layer stack 320, may extend beyond the periphery of the third piece 700c of the mold 700. As described above with reference to FIG. 7, the continuous layer stack 320 may be mechanically pressed and exposed to high temperatures to laminate and seal the single continuous layer stack 320 to produce the two-sided sealed GDE assembly 400 in one step. In some embodiments, the pressing process may provide pairs of seals that extend along the lateral 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 of the continuous layer stack 320 may provide a sufficient hydraulic barrier along the bottom periphery 406 of the GDE assembly 400.

[0083] While the embodiment shown and described with reference to FIG. 9 includes a "one-step" lamination and sealing assembly process, it will be appreciated that similar techniques can be utilized to form a GDE assembly 400 from a single layer stack 320 using a "two-step" lamination and sealing assembly process. In particular, the layer stack 320 described above can be pressed (e.g., hot pressed) in an initial step to provide a laminated structure having a desired three-dimensional shape as described above with reference to FIG. 5B. For example, the initial lamination step can provide a pair of laminated GD electrodes 203 arranged back-to-back on a single laminate sheet. The laminate sheet can be folded into a clam-shell shape and placed in a mold 700 as shown in FIG. 9, or can be placed in a mechanical press 505 as shown in FIGS. 5C and 5D. A second mechanical press step at elevated temperature can be used to seal the continuous laminated structure to obtain a two-sided sealed GDE assembly 400.

[0084] FIG. 10 illustrates a schematic of an alternative one-step lamination and sealing process that can be used to simultaneously fabricate multiple GDE assemblies according to embodiments of the present disclosure. FIG. 10 illustrates an apparatus 1000 including a pair of molds 903a and 903b positioned adjacent to one another. As described above with reference to FIG. 7, each of the molds 903a and 903b may include a three-part 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. The first continuous layer stack 320a may be placed in the apparatus 1000 such that the first continuous layer stack 320a extends between the first piece 700a and the third piece 700c of the first mold 903a and between the first piece 700a and the third piece 700c of the second mold 903b. The second continuous layer stack 320b may be placed in the apparatus 100 such that the second continuous layer stack 320a extends between the second piece 700b and the third piece 700c in the first mold 903a and between the second piece 700b and the third piece 700c in the second mold 903b. In some embodiments, one or more feeders, such as rollers (not shown in FIG. 10 ), may be used to feed the respective layer stacks 320a and 320b to the apparatus 1000. While the heat source 701 is used to heat the layer stacks 320a and 320b, the apparatus 1000 may mechanically press the layer stacks 320a and 320b in the molds 903a and 903b to laminate and seal the layer stacks 320a and 320b to produce the pair 400 of double-sealed GDE assemblies. In some embodiments, the cutting device 904 may cut the layer stacks 320a and 320b during the pressing process to separate the two GDE assemblies 400 produced during the pressing step.

[0085] 10 shows two successive layer stacks 320a and 320b within the apparatus 1000, it will be appreciated that in some embodiments, a single layer stack 320 may be placed within the apparatus 1000 such that the layer stack 320 folds over the top and bottom surfaces of the third pieces 700c of respective molds 903a and 903b as shown in FIG 9. In this manner, the single layer stack 320 may be used to manufacture a pair of GDE assemblies 400 in a one-step lamination and sealing process.

[0086] Further, while the embodiment shown and described with reference to FIG. 10 includes a "one-step" stacking and sealing assembly process, it will be understood that a similar process can be utilized to form multiple GDE assemblies 400 using a "two-step" stacking and sealing assembly process. In particular, the pair of continuous layer stacks 320a and 320b described above can be pressed (e.g., hot pressed) in an initial step to provide a stacked GD electrode pair 203 on a single stacked sheet. The stacked sheet can be placed in an apparatus 1000 including dies 903a and 903b as shown in FIG. 10, or can be placed in an apparatus including a pair of mechanical pressing devices 505 as shown in FIGS. 5C and 5D. A second mechanical pressing step at elevated temperature can be used to seal the continuous stacked structure to provide a pair of two-sided sealed GDE assemblies 400. A cutting device 904 as shown in FIG. 10 can separate the individual GDE assemblies 400.

[0087] 10 depicts a die assembly 1000 including die pairs 903a and 903b positioned adjacent to one another, it will be understood that die assembly 1000 may include more than two dies 903 or press units 505 and may simultaneously produce more than two GDE assemblies 400. Die assembly 1000 may include a line of dies 903 / press units 505 arranged along one direction, or may include a two-dimensional array of dies 903 / press units 505 extending along two perpendicular directions.

[0088] In some embodiments, a dual-sealed GDE assembly 400 formed using a "one-stage" or "two-stage" lamination and sealing process may include at least one exterior surface having a textured, contoured, and / or roughened three-dimensional shape. In particular, the central region(s) 410 (see FIGS. 4A-4D) of the front face 403 and / or rear face 404 of the GDE assembly 400 may include a textured, contoured, and / or roughened surface rather than a substantially planar surface as shown in FIGS. 4A-4D. The textured, contoured, and / or roughened surface may increase the surface area of ​​the GDE assembly 400 and increase the area and / or amount of three-phase boundaries. FIGS. 11A-11C are cross-sectional views of an exemplary GDE assembly 400 having a contoured exterior surface. In particular, the front surface 403 and rear surface 404 of the GDE assembly of FIGS. 11A-11C include ribbed structures such as sawtooth ribs 1101 (FIG. 11A), sinusoidal wave ribs 1102 (FIG. 11B), and rectangular wave ribs 1103 (FIG. 11C). Other suitable three-dimensional undulations, textures, and / or patterns may also be used. The textured, undulating, and / or roughened shapes may be formed during the lamination process used to fabricate the laminated GD electrodes 203a and 203b. For example, the molds 500, 700, 903a, 903b as shown in FIGS. 5A-5B and 7-10 may be shaped to impart a textured, undulating, and / or roughened three-dimensional shape to the layer stack 320 during any of the "one-step," "two-step," or "three-step" lamination and sealing processes described above.

[0089] 12A-12C are diagrams of a reduced active area GDE assembly 400 and a manufacturing process for the GDE assembly 400 according to embodiments of the present disclosure. In some cases, it may be advantageous to limit the size of the active electrode layer material(s) used in the stacked GD electrode 203 and / or GDE assembly 400. For example, limiting the area of ​​the active layer 311 to only the electrochemically active areas of the electrode 203 and / or GDE assembly 400 (i.e., areas where an air-liquid interface may occur) may help reduce the cost of the electrode / GDE assembly. FIG. 12A is a top view of a layer stack 320 including at least one active layer 311, at least one backing layer 313, and an optional current collector 315. In a non-limiting embodiment, the layer stack 320 may include an active layer 311 located above or below a pair of backing layers 313, with the current collector 315 located between the pair of backing layers 313. The current collector 315 may extend partially beyond the periphery of the active layer 311 and the backing layer 313 at the first end 1201 of the stack 320. A length and / or width dimension of the active layer 311 may be less than a corresponding length and / or width dimension of at least one backing layer 313, such that a surface of the backing layer 313 may be exposed adjacent to the active layer 311 in a gap region 1205 along the periphery of the layer stack 320. In the embodiment shown in FIG. 12A, the gap region 1205 extends continuously along the side edges 1203 and 1204 and the bottom edge 1202 of the layer stack.

[0090] 12B and 12C are front and side views of a GDE assembly 400 that may be formed using the layer stack 320 as shown in FIG. 12A. The GDE assembly 400 may 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 layer stack 320 shown in FIG. 12A may form a laminated GD electrode 203a located on one side (i.e., face) 403 of the double-sealed GDE assembly 400. A second laminated GD electrode 203b may form an opposite side (i.e., face) 404 of the double-sealed GDE assembly 400. As shown in FIG. 12B and 12C, the active layer 311 of the electrode 203a is located on a central region 410 and extends to a top peripheral edge 411 of the GDE assembly 400 and also extends over a recess 409 of the GDE assembly 400. In this embodiment, the active layer 311 does not extend onto the bottom perimeter 406 or the side perimeters 407 and 408 of the GDE assembly 400. In some embodiments, the active layer 311 may not be present on the substantially planar flat portion 405 of the GDE assembly 400. In other embodiments, the active layer 311 may extend onto portions of the planar flat portion 405, but may not extend onto the bottom perimeter 406 and / or the side perimeters 407 and 408 of the GDE assembly 400. In some embodiments, the backing layer 313 may be exposed on the planar flat portion 405 of the GDE assembly 400.

[0091] 13A-13C illustrate a reduced active area GDE assembly 400 and a process for fabricating the GDE assembly 400 according to another embodiment of the present disclosure. The embodiment of FIG. 13A-13C is similar to FIG. 12A-12C, except that the active layer 311 does not extend to the top periphery 411 of the GDE assembly 400. In many instances where the GDE assembly 400 is immersed in a liquid electrolyte bath, the electrolyte level may not reach the top of the GDE assembly 400. Furthermore, 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 shows a schematic of the range 1302 of the liquid level during normal battery operation. Because the top of the GDE assembly 400 is not always wetted by the electrolyte, cost savings may be achieved by using a reduced active area where the active layer 311 does not extend to the top periphery 411 of the GDE assembly 400. However, it may be undesirable to leave the backing layer 313 exposed in this region, since changes in electrolyte level mean that the backing layer 313 is often directly exposed to the liquid electrolyte. To address this issue, a strip 1300 of inert sealing material may be provided on the outer surface of the electrode(s) 203a, 203b at or near the top periphery 411 of the GDE assembly 400. FIG. 13A is a top view of a layer stack 320 including at least one active layer 311, at least one backing layer 313, and a current collector 315. The active layer 311 does not extend to the top periphery 1201 of the layer stack 320 such that there is a gap region 1301 between the periphery of the active layer 311 and the top periphery 1201 of the layer stack 320. The strip 1300 of inert sealing material may be provided over all or a portion of the gap region 1301 on the layer stack 320. The inert encapsulation material 1300 may extend between the lateral peripheral edges 1203 and 1204 of the layer stack 320, and in some embodiments may extend to the top peripheral edge 1201 of the layer stack 320. In other embodiments, such as shown in FIG. 13A, the inert encapsulation material 1300 may not extend to the top peripheral edge 1201 of the layer stack 320, such that a region of the backing layer 313 may be exposed adjacent the top peripheral edge 1201 of the layer stack 320.The inert sealing material 1300 may be composed of a suitable material that is not electrochemically active in the completed electrode / GDE assembly, and further prevents or inhibits liquid electrolyte from wetting through the sealing material 1300 to the inside of the GDE assembly. In some embodiments, the inert sealing material 1300 may include a plastic sheet or membrane.

[0092] 13B and 13C are front and side views of a GDE assembly 400 that may be formed using the layer stack 320 as shown in FIG. 13A. The GDE assembly 400 may 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 laminated GD electrodes 203a and 203b that make up the GDE assembly 400 may include a strip of inert sealing material 1300 that extends to the upper region of the electrodes 203a and 203b. The active layers 311 of the electrodes 203a and 203b may be located vertically below and adjacent the strip of inert sealing material 1300. The strip of inert sealing material 1300 may at least partially overlap the range of liquid level positions 1302 during normal battery operation. In various embodiments, the top edge of the strip of inert sealing material 1300 may be located above the top end of the range of liquid level positions 1302. In some embodiments, the strip 1300 may extend to the top periphery 411 of the GDE assembly 400. In other embodiments, such as shown in Figures 13B and 13C, the top edge of the strip 1300 may be located below the top periphery 411 of the GDE assembly 400. The backing layer 313 may be exposed between the top edge of the strip 1300 and the top periphery 411 of the GDE assembly 400. In some embodiments, the bottom end of the range 1302 of liquid level positions may be below the bottom edge of the strip 1300 and may correspond to the position of the active layer 311.

[0093] 14A and 14B are top and side views, respectively, of a GDE assembly 1400 according to another embodiment of the present disclosure. Referring to FIG. 14A and FIG. 14B, the GDE assembly 1400 includes a laminated GD electrode 203 on a first side (e.g., front) 403 of the GDE assembly 1400. An opposite side (e.g., rear) 404 of the GDE assembly 1400 includes a planar surface 1401. The laminated GD electrode 203 may have an undulating three-dimensional shape including a flat planar portion 405 adjacent the bottom peripheral edge 406a and the side peripheral edges 407, 408 of the laminated GD electrode 203, and a convex portion 409 extending from the flat planar portion 405 to a raised central region of the laminated GD electrode 203. The laminated GD electrode 203 may be bonded to a second member 1402, which may be a substantially flat sheet or substrate that forms a planar surface 1401 on the rear face 404 of the GDE assembly 1400. The GDE assembly 1400 may include an opening to an interior chamber 401 located between the GD electrode 203 and the second member 1402 at a top periphery 411 of the GDE assembly 1400. The GDE assembly 1400 may be sealed to hydraulically isolate the interior chamber 401 from the surrounding liquid electrolyte. The GDE assembly 1400 may be sealed using any of the methods described above, for example, by hot pressing (with or without a sealant material) the laminated GD electrode 203 and the second member 1402 surrounding the flat planar portion 405 of the GD electrode 203 to form a continuous seal along the side and bottom faces of the assembly 1400. Alternatively, or additionally, an external seal may be used to seal the edges of the assembly 1400 between the GD electrode 203 and the second member 1402.

[0094] In some embodiments, the second member 1402 may be electrochemically inert. For example, the second member 1402 may be a supporting substrate, which may be made of plastic or another suitable material. In embodiments in which the second member 1402 is electrochemically inert, the GDE assembly 1400 includes an electrode 203 on a first side (e.g., front) 403 of the GDE assembly 1400, but does not include an electrode on an opposite side (e.g., rear) 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 member 1402 may be electrochemically active and may include a planar electrode on the second side (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 laminated GD electrode 203 may be formed using any of the methods described above. For example, the GD electrode 203 may be formed using a two-step process that includes pressing a layer stack in a mold at high temperature to form the GD electrode 203 in the desired three-dimensional shape, followed by a second step of bonding and sealing the GD electrode 203 to the second member 1402, such as using a heated mechanical press. Alternatively, the GDE assembly 1400 may be formed in a one-step process that may include molding the laminated GD electrode 203 in a mold and simultaneously sealing the GD electrode 203 to the second member 1402.

[0097] 15A and 15B are front and top views, respectively, of a two-sided sealed GDE assembly 400 including an insert 1500 within the internal chamber of the GDE assembly 400 according to an embodiment of the present disclosure. The insert 1500 may include open areas or channels that define flow fields as described above with reference to FIG. 3A. The insert 1500 may define a pair of flow fields configured to deliver air to the rear side of the respective GD electrodes 203a and 203b. The insert 1500 may be constructed of a suitable material, such as a plastic and / or metal material. In some embodiments, the insert 1500 may be inserted into the internal chamber 401 of the GDE assembly 400 such that the flow fields may be pressed against the adjacent electrodes 203a and 203b. In some embodiments, an adhesive material may be used to bond the insert 1500 to the adjacent electrode surfaces. A filler material may optionally be provided around the periphery of the insert 1500 to fill the remaining volume of the chamber 401, such as the non-electrochemically active areas of the GDE assembly 400. The insert 1500 is located within the sealed interior chamber 401 of the GDE assembly 400, and the insert 1500 is not exposed to the potentially caustic liquid electrolyte. Thus, less durable and / or less expensive materials may be used. Furthermore, because the insert 1500 is not directly exposed to the electrolyte, the insert 1500 construction does not need to be liquid-tight. One or more conduits 1503 and 1503 may direct air to and from the insert 1500.

[0098] In some embodiments, the insert 1500 may be constructed of or include a conductive material (e.g., a metallic material) that may contact the electrodes 203a and 203b. In such embodiments, the insert 1500 may be used as a replacement or supplement to the conductive current collectors embedded in the laminated GD electrodes 203a and 203b.

[0099] 16A-16C illustrate a method of manufacturing a double-sealed GDE assembly 400 having an internal conductive member 1603 according to yet another embodiment of the present disclosure. Referring to FIG. 16A, a layer stack 320 is provided that includes an active layer 311, a pair of backing layers 313, and a current collector 315 between the pair of backing layers 313. Heat and pressure may be applied to the layer stack 320 (indicated by arrows in FIG. 16A) to produce a laminated GD electrode 203a as shown in FIG. 16B. As shown in FIGS. 16A and 16B, portions of the current collector 315 and at least one backing layer 313 on the edge 1601 of the layer stack 320 may remain unlaminated. As shown in FIG. 16B, the unlaminated portion of the current collector 315 may be attached to a conductive member 1603. In some embodiments, the conductive member 1603 may be a bus bar. The current collector 315 may be attached to the conductive member / busbar 1603 using any suitable method, such as a separate lamination process.

[0100] 16B and 16C, the unlaminated portion of the current collector 315 and the conductive member / busbar 1603 may be bent or folded over such that the conductive member / busbar 1603 is on a surface of the laminated GD electrode 203a. As shown in FIG. 16C, the conductive member / busbar 1603 may be attached to the unlaminated portion of the current collector 315 of the second laminated GD electrode 203b. As shown in FIG. 16C, the unlaminated portions of the backing layers 313 of the first laminated GD electrode 203a and the second laminated GD electrode 203b may be joined together to form a two-sided sealed GDE assembly 400 having a seal 1605 that extends around the periphery of the assembly 400. The conductive member / busbar 1603 may be on the same side of the interior chamber 401 of the GDE assembly 400 as the seal 1605, so that the GDE assembly 400 may not be exposed to the liquid electrolyte when immersed in an electrolyte bath. This may eliminate the need to protect the conductive members / bus bars 1603 below the electrolyte level. In some embodiments, the conductive members / bus bars 1603 may extend vertically (into and out of the page of FIGS. 16A-16C) when the GDE assembly 400 is immersed in the electrolyte.

[0101] 17A and 17B show a method of manufacturing a double-sealed GDE assembly 1700 having a pair of planar GD electrodes 1701a and 1701b attached to a support frame 1703. FIG. 17A is a cross-sectional view of the pair of planar GD electrodes 1701a and 1701b and the support frame 1703 in a mechanical press 1705 during the manufacturing process of the double-sealed GDE assembly 1700. FIG. 17B is a perspective view of the completed double-sealed GDE assembly 1700. Referring to FIG. 17A, each of the GD electrodes 1701a and 1701b can be a laminated GD electrode that can be formed by mechanically pressing (e.g., hot pressing) a layer stack including at least one active layer and at least one backing layer at high temperature as described above. The laminated GD electrodes 1701a and 1701b can also include embedded current collectors. As shown in Figures 17A and 17B, the laminated GD electrodes 1701a and 1701b can have planar outer surfaces, or the laminated GD electrodes 1701a and / or 1701b can have textured, contoured, and / or roughened outer surfaces, as shown in Figures 11A-11C.

[0102] The support frame 1703 may have one or more sidewalls 1704 extending around the perimeter of the support frame 1703. The one or more sidewalls 1704 may surround an open area 1702 inside the sidewalls 1704. The support frame 305 may be constructed of a suitable structural material such as a plastic (e.g., polypropylene, HDPE, acrylonitrile butadiene styrene (ABS) (e.g., carbon fiber ABS, fiberglass reinforced ABS, etc.), etc.) and / or metal (e.g., steel, nickel, etc.) material. The sidewalls 1704 of the support frame 1703 may be constructed of a material that is durable enough to withstand long-term exposure to liquid electrolyte.

[0103] One or more side walls 1704 may extend continuously around a portion of the periphery of the support frame 1703. One or more openings (not shown in FIG. 17A and FIG. 17B ) through the side wall(s) 1704 may provide access to the open area 1702 of the support frame 1703. In some embodiments, the support frame 1703 may have a generally polygonal shape, such as a rectangle or a square, as shown in FIG. 17B . A 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. A fourth side of the support frame 1703 may optionally be open to the open area 1702. Other suitable shapes of the support frame 1703, such as shapes having one or more curved side walls 1704, are within the contemplation of the disclosure.

[0104] 17A, the laminated GD electrodes 1701a and 1701b and the support frame 1703 may be placed in a mechanical press 1705. The support frame 1703 may be positioned between the respective GD electrodes 1701a and 1701b with the active layers of the electrodes 1701a and 1701b facing outward. A sealant material, such as a thermoplastic material, an epoxy material, a hot melt adhesive material, or the like, may optionally be positioned between the sidewalls 1704 of the support frame 1703 and the respective GD electrodes 1701a and 1701b. A pair of heated press plates 1707 may press the GD electrodes 1701a and 1701b against the support frame 1703, as shown by the arrows in Figure 17A, to bond the GD electrodes 1701a and 1701b to the support frame 1703 and form a continuous seal between the electrodes 1701a and 1701b and the adjacent side wall(s) 1704 of the support frame 1703. In the embodiment shown in Figure 17A, both the GD electrodes 1701a and 1701b are bonded and sealed to the support frame 1703 simultaneously, although it will be understood that the GD electrodes 1701a and 1701b may be bonded to the support frame 1703 sequentially using separate pre-steps. In various embodiments, the pressure and / or temperature used to bond the GD electrodes 1701a and 1701b to the support frame 1703 may be lower than the pressure and / or temperature used to laminate the GD electrodes 1701a and 1701b.

[0105] In one embodiment, a vacuum source (not shown in FIG. 17A) may be fluidly coupled to the open area 1702 of the support frame 1703 during the mechanical pressing step. The vacuum source may be used to create a negative pressure in the open area 1702 of the support frame 1703 that may draw the sealant material into the pores of the adjacent backing layers of the GD electrodes 1701a and 1701b. This may be effective in improving the integrity of the seal formed between the GD electrodes 1701a and 1701b and the support frame 1703.

[0106] In some embodiments, the support frame 1703 may include an interior portion extending between the sidewall(s) 1704 that may define a flow field(s) adjacent the respective GD electrodes 1701a and 1701b. Alternatively, an insert (which may be similar to the insert 1500 shown in FIGS. 15A and 15B) may be inserted into the open region 1702 of the support frame 1703 through an opening in the support frame 1703. The insert may define a flow field(s) adjacent the respective GD electrodes 1701a and 1701b.

[0107] In some embodiments, the support frame 1703 and / or inserts within the support frame 1703 may be constructed of or include a conductive material (e.g., a metallic material) that may contact the electrodes 1701a and 1701b. In such embodiments, the support frame 1703 and / or inserts may be used as a replacement or supplement to the conductive current collectors embedded in the laminated GD electrodes 1701a and 1701b.

[0108] As discussed above, in some embodiments, a pair of planar GD electrodes 203 may be joined and sealed along edges to provide a two-sided sealed GD electrode assembly. However, bending and deforming the GD electrodes to create sealed edges in the above configurations may affect their durability and / or performance, as well as limit the flow field. Thus, as discussed above with respect to FIGS. 17A and 17B, a support frame may be used in some embodiments to provide a separate perimeter to the sealed GD electrode assembly. The support frame 1703 may be made of any number of suitable materials, such as plastic (e.g., polypropylene, HDPE, acrylonitrile butadiene styrene (ABS) (e.g., carbon fiber ABS, fiberglass reinforced ABS, etc.) and / or metal (e.g., steel, nickel, etc.) materials, and may be pressed in between the laminated GD electrodes 1701a and 1701b using a pair of heated press plates or other suitable heat sealing device. In this manner, the frame material (eg, ABS, etc.) may be melted at the interface with each GD electrode.

[0109] However, for some materials, the mismatch in coefficient of thermal expansion (CTE) may be too great to use a heated press plate to seal the GD electrodes to the support frame. For example, ABS may expand during heat sealing and then contract when cooled to room temperature. Such changes can cause surface disturbances or residual stresses in the GD electrodes, potentially causing other problems (e.g., short circuits) in the battery.

[0110] In some embodiments, a first sealant material may be used to attach the stacked GD electrode to a support frame, eliminating the need for heat treatment to create a continuous seal.

[0111] Referring to FIG. 18A, each of the GD electrodes 1801a and 1801b may be a laminated GD electrode that may be formed from a layer stack including at least one active layer and at least one backing layer. As a specific example, the GD electrodes 1801a and 1801b may be a laminated GD electrode that may be formed by mechanically pressing (e.g., hot pressing) a layer stack including at least one active layer and at least one backing layer at high temperature as described above, or may be a laminated GD electrode formed in other ways. The laminated GD electrodes 1801a and 1801b may also include embedded current collectors 1810 that do not extend to the edges where the respective GD electrodes are sealed to the adjacent surface of the support frame 1803. The laminated GD electrodes 1801a and 1801b may have planar outer surfaces as described with respect to various embodiments herein.

[0112] In some embodiments, the support frame 1803 may be constructed from a plastic (e.g., ABS) and the first sealant 1805 may be any of a variety of adhesives or thermoplastic materials, such as ABS. Bonding the GD electrodes 1801a and 1801b to the support frame 1803 in this manner does not require heat treatment, and normal operation of a product (e.g., a battery) that includes such a GD electrode assembly in place will experience thermal cycling, potentially creating the same CTE mismatch described above between the support frame material and the electrodes bonded to the frame.

[0113] Thus, in various embodiments, the support frame 1803 may be made using a glass fiber reinforced or carbon fiber reinforced polymer to bring the CTE of the frame closer to that of the GD electrode. Additionally, in some embodiments, the support frame 1803 may be made of metal (e.g., carbon steel, nickel plated carbon steel, etc.) or other rigid material (e.g., graphite, etc.).

[0114] The use of the first sealant without heat treatment may be suitable but may also present durability risks. Specifically, potential leakage paths may exist at the interface between the support frame and the adjacent GD electrode. In particular, if the backing layer(s) of the laminated GD electrode described above are not normally designed to be exposed to electrolyte, the use of only the first sealant may increase the likelihood of subsequent product failure.

[0115] To mitigate such risks, the support frame 1803 according to some embodiments may be designed to include features 1822 for another sealant material, as shown in FIG. 18B. Specifically, the features 1822 incorporated 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 according to various embodiments may include any of a number of suitable adhesive materials, such as one or more epoxies. The second sealant 1805 may be an epoxy that has been found to be resistant to electrolytes and wetness to seal any potential leak paths in the GD electrode assembly.

[0116] In some embodiments, a two-sided sealed GD electrode assembly 1800 may be made by sealing planar GD electrodes 1801a, 1801b to both sides of a support frame 1803 with a first sealant 1805, followed by filling the features 1822 with a second sealant 1805. Alternatively, the second sealant may be provided prior to bonding the GD electrodes to the support frame in some embodiments.

[0117] An embodiment process 1900 for manufacturing a double-sided sealed GD electrode assembly is shown in FIG. 19A and FIG. 19B. First, a support frame 1803 made of a rigid material may be provided. The rigid material may be durable enough to withstand long-term exposure to liquid electrolyte (e.g., ABS). In some embodiments, the support frame 1803 may be formed from a plurality of H-channel sidewalls surrounding the perimeter inside an open area. In some embodiments, the support frame 1803 may have at least three H-channel sidewalls that extend continuously to form three sides of a square or rectangle, with the fourth side being open. The fourth side may be open. Other suitable shapes of the support frame 1803, such as U-shaped, V-shaped, etc., are within the contemplated scope of the disclosure.

[0118] In a next step of the process 1900, a layer of a first sealant 1805a (e.g., ABS cement) may be applied to a first surface of the support frame 1803. Such application may be performed using any of a variety of dispensing methods.

[0119] In the next step of the process 1900, a first planar GD electrode 1801a may be placed on a first side of the support frame 1803 containing the first sealant 1805a and allowed to cure naturally. In some embodiments, the GD electrode used in the process 1900 may be a laminated GD electrode manufactured in a separate lamination process. For example, a layer stack including at least one active layer, at least one backing layer, and a current collector (e.g., copper) may be hot pressed together as described herein. In various embodiments, the manufacture of the GD electrode may involve intentionally not placing a current collector in the area where the first sealant contacts to avoid electrical conductivity in that area, thereby reducing the risk of short circuit development.

[0120] The next step may be to invert the support structure 1803 and apply a layer of a first sealant 1805b to the opposite side of the support frame 1803 in a similar manner to layer 1805a.

[0121] In the next step of the process 1900, a second planar GD electrode 1801b may be placed on the opposite side of the support frame 1803 containing the first sealant 1805b and allowed to air cure, thereby producing a two-sided sealed GD electrode assembly 1902. In various embodiments, each manufacturing step in the method 1900 may take on the order of several minutes. The steps used to manufacture the two-sided sealed GD electrode assembly 1902 may be repeated several times to produce multiple assemblies according to some embodiments.

[0122] As shown in FIG. 19B, multiple GD electrode assemblies (e.g., 1902a, 1902b, etc.) may be aligned with one another, stacked vertically, and clamped to form a single large fixture 1920. In a next step of the process 1900, the features 1822 (e.g., channels) of the support frame 1803 may be filled with a second sealant 1832 (e.g., epoxy). In various embodiments, the second sealant may be filled from the top of the fixture 1920 or may be injected from the bottom, for example, through holes in the support frame 1803.

[0123] In various embodiments, the outer edges of the support frame are shown flush with the GD electrodes, although other suitable configurations are within the contemplated scope of the disclosure. For example, the support frame may extend further out from the edges of the joined GD electrodes in some assemblies for various reasons (e.g., handling and / or alignment of features, mating / interlocking with battery cell lids, etc.).

[0124] 20A and 20B show a method of manufacturing a large area laminated GD electrode 2000 with an interconnected seam 2001. Referring to FIG. 20A and 20B, the side edges 2002a and 2002b of the pair of electrode structures 2003a and 2003b may be folded over one another as shown in FIG. 20A. The electrode structures 2003a and 2003b may be pre-laminated layer stacks 320 as shown in FIG. 3B. Alternatively, one or both of the electrode structures 2003a and 2003b may be laminated electrodes with unlaminated edge portions as shown in FIG. 16A and 16B. Mechanical pressure may be applied to the side edges 2002a and 2002b at elevated temperature as shown by the arrows in FIG. 20A to join the interconnected side edges 2002a and 2002b to form a seam 2001 as shown in FIG. 20B. In this way, a large area planar laminate GDE electrode 2000 can be fabricated from smaller area layer stacks and / or electrodes. In some embodiments, the seam 2001 created by the method shown in Figures 20A and 20B can form an edge seal for an electrode assembly, such as the two-sided sealed GDE assembly 400 shown in Figures 4A-4D.

[0125] 21A-21E illustrate a method for manufacturing a dual-sealed GDE assembly 2100 using a one-step "flat press" lamination and sealing process according to an embodiment of the present disclosure. 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 backing layers 313, and a current collector 315 between the pair of backing layers 313, as described above. The layer stacks 320a and 320b and the spacer 2101 may be placed in a heat press apparatus configured to apply heat and mechanical pressure to the layer stacks 320a and 320b and the spacer 2101. The spacer 2101 may have a width narrower than the width of the backing layer 313 such that the spacer 2101 does not extend to the opposing first and second peripheral edges 2102 and 2103 of the layer stacks 320a and 320b. Thus, the backing layers 313 of the respective layer stacks 320a and 320b may contact each other along the first and second peripheral edges 2102 and 2103 of the layer stacks 320a and 320b. In some embodiments, to avoid corrosion of the current collector 315 in the assembled GDE assembly 2100, the current collector 315 may not extend to the first and second peripheral edges 2102 and 2103 of the layer stacks 320a and 320b.

[0126] The spacer 2101 may extend up to and / or beyond the third perimeter 2104 of the layer stacks 320a and 320b. Thus, the spacer 2101 may be located between the backing layers 313 of the respective layer stacks 320a and 320b along the third perimeter 2104. In some embodiments, the spacer 2101 may be offset from the fourth perimeter 2105 of the layer stacks 320a and 320b opposite the third perimeter 2104. Thus, the backing layers 313 of the layer stacks 320a and 320b may contact each other along the fourth perimeter 2105. Alternatively, the spacer 2101 may extend up to and / or beyond the fourth periphery 2105 such that the spacer 2101 may be located between the backing layers 313 of the respective layer stacks 320a and 320b along the fourth periphery 2105. A sealant material, as described above with reference to Figure 5, may optionally be provided between the contacting surfaces of the backing layers 313 of the respective layer stacks 320a and 320b.

[0127] The spacer 2101 may be composed of a material that does not bond strongly to adjacent layers of the layer stacks 320a and 320b when heat and pressure are applied to the layer stacks 320a and 320b. Thus, the spacer 2101 may also be referred to as a "release layer." The spacer / release layer 2101 may include, for example, a film, foil, sheet, thin film, shim, or other similar structure, including various combinations thereof. Suitable materials for the spacer / release layer 2101 include metals (e.g., steel, aluminum, etc.), fiber reinforced plastics (e.g., fiberglass), ceramics, carbon fiber or other graphite compounds, plastics or polymers with high thermal stability, and combinations thereof. Other suitable materials for the spacer / spacer 2101 are within the contemplated scope of the disclosure. The spacer / release layer 2101 may be a reusable component or a consumable / disposable component intended for single use only. In some embodiments, the spacer / release layer 2101 can have a total thickness of from about 0.001 to about 2 mm, although greater or lesser thicknesses may be used for the spacer / release layer 2101.

[0128] In a one-step "flat press" lamination and sealing process, the layer stacks 320a and 320b and the spacer / release layer 2101 may be laid flat in a heat press apparatus, rather than in a mold cavity having one or more contoured interior surfaces designed to impart a three-dimensional shape to the layer stacks 320a and 320b, as described above with reference to Figures 5A-5B and 7. In contrast, in a "flat press" process, the heat press apparatus may include a heated press platen having a planar surface configured to apply substantially uniform heat and pressure to the flat exterior surfaces of the layer stacks 320a and 320b. The heat press apparatus may apply sufficient heat and pressure to the layer stacks 320a and 320b and the spacer / release layer 901 (indicated by arrows in Figure 21A) to produce a two-sided sealed GDE assembly 2100 including a pair of laminated GD electrodes 203a and 203b having the spacer / release layer 2101 therebetween, as shown in Figure 21B. The embodiment shown in Figures 21A and 21B is a "one-step" process in which the individual layer stacks 320a and 320b are laminated and sealed together (with or without sealant material) at the same time. Following the heat press process, the laminated GD electrodes 203a and 203b may be sealed at least along the first and second periphery edges 2102 and 2103 of the GDE assembly 2100. In embodiments in which the spacer / release layer 2101 is offset from the fourth periphery edge 2105, the laminated GD electrodes 203a and 203b may also be sealed along the fourth periphery edge 2105 of the GDE assembly 2100. An additional outer seal, as described above with reference to Figure 6, may optionally be provided over the sealed edges of the GDE assembly 2100. The active layer 311 may be exposed to 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 GDE assembly 2100 can be substantially flat.

[0129] 21C and 21D, the spacer / release layer 2101 may be removed from the GDE assembly 2100. FIG. 21C is a perspective view of the GDE assembly 2100, and FIG. 21D is a top view of the GDE assembly 2100 with the spacer / release layer 2101 removed. A cavity 2108 may be located in the space between the GD electrodes 203a and 203b from which the spacer / release layer 2101 was removed. The sealing edge of the GDE assembly 2100 may surround the cavity 2108. The width of the cavity 2108 may be expanded by applying a force to the GDE assembly 2100 to form a pocket-like or pouch-like structure, as shown in FIG. 21E. At least one flow field-defining insert 1500 may be inserted into the cavity 2108, as described above with reference to FIGS. 15A and 15B.

[0130] In an alternative embodiment, a two-step "flat press" lamination and sealing process may be used to provide the two-sided sealed GDE assembly 2100. In the two-step "flat press" lamination and sealing process, the individual layer stacks 320a and 320b are first laminated together to form the isolated GD electrodes 203a and 203b. The isolated GD electrodes 203a and 203b may have substantially flat outer surfaces. The isolated GD electrodes 203a and 203b may then be placed in a heat press apparatus with the spacer / release layer 2101 located between the GD electrodes 203a and 203b. The heat press apparatus may then be used in a "flat press" process as described above to seal the peripheries of the GD electrodes 203a and 203b together resulting in a two-sided sealed GDE assembly 2100 with the spacer / release layer 2101 between the respective GD electrodes 203a and 203b as shown in FIG. 21B. In some embodiments, the GD electrodes 203a and 203b may be sealed by a "flat press" process using the same heat press equipment used for lamination of the layer stacks 320a and 320b. Alternatively, different heat press equipment may be used for the separate lamination and sealing steps. After the "flat press" sealing process, the spacer / release layer 2101 may be removed, as shown in Figures 21C and 21D, and the cavity 2108 between the GD electrodes 203a and 203b may expand to form a pocket-like or pouch-like structure, as shown in Figure 21E.

[0131] Various embodiments described and illustrated herein may provide devices and / or methods for use in bulk energy storage systems, such as long-term energy storage (LODES) systems, short-term energy storage (SDES) systems, etc. As an example, various embodiments may provide batteries (e.g., battery 200) for bulk energy storage systems, such as batteries for LODES systems. Renewable energy sources are becoming increasingly prevalent and cost-effective. However, many renewable energy sources face intermittency issues that hinder the adoption of renewable energy sources. The impact of the intermittent tendency of renewable energy sources may be mitigated by pairing them with bulk energy storage systems, such as LODES systems, SDES systems, etc. To support the adoption of combined generation, transmission, and storage systems (e.g., renewable generation sources paired with bulk energy storage systems, and power plants with transmission facilities in either the power plant and / or the bulk energy storage system), devices and methods are needed to support the design and operation of such combined generation, transmission, and storage systems, such as the various embodiment devices and methods described herein.

[0132] A combined generation, transmission, and storage system may be a power plant that includes one or more generation sources (e.g., one or more renewable generation sources, one or more non-renewable generation sources, a combination of renewable and non-renewable generation sources, etc.), one or more transmission facilities, and one or more bulk energy storage systems. The transmission facilities in either the power plant and / or the bulk energy storage systems may be co-optimized with the generation and storage systems or may impose constraints on the design and operation of the generation and storage systems. The combined generation, transmission, and storage system may be configured to meet various output targets under various design and operational constraints.

[0133] 22-23 illustrate various exemplary systems in which one or more aspects of various embodiments can be used as part of a bulk energy storage system, such as a LODES system, an SDES system, etc. For example, various embodiments described herein with reference to FIGS. 1A-93 can be used as batteries for a bulk energy storage system, such as a LODES system, an SDES system, etc., and / or various electrodes described herein can be used as components of a bulk energy storage system. As used herein, the term "LODES system" refers to a bulk energy storage system configured to have a rated duration (energy / power ratio) of 24 hours (h) or longer, such as a duration of 24 hours, a duration of 24 hours to 50 hours, a duration of more than 50 hours, a duration of 24 hours to 150 hours, a duration of more than 150 hours, a duration of 24 hours to 200 hours, a duration of more than 200 hours, a duration of 24 hours to 500 hours, a duration of more than 500 hours, etc.

[0134] FIG. 22 illustrates an exemplary system in which one or more aspects of the various embodiments may be used as part of a bulk energy storage system. As a specific example, a bulk energy storage system incorporating one or more aspects of the various embodiments may be a LODES system 2404. As an example, the LODES system 2404 may include various embodiment batteries described herein, various electrodes described herein, and the like. The LODES system 2404 may be electrically connected to a wind farm 2402 and one or more transmission facilities 2406. The wind farm 2402 may be electrically connected to the transmission facility 2406. The transmission facility 2406 may be electrically connected to a power grid 2408. The wind farm 2402 may generate power, and the wind farm 2402 may output the generated power to the LODES system 2404 and / or the transmission facility 2406. The LODES system 2404 may store the power received from the wind farm 2402 and / or the transmission facility 2406. The LODES system 2404 can output the stored power to a transmission facility 2406. The transmission facility 2406 can output power received from one or both of the wind farm 2402 and the LODES system 2404 to a grid 2408 and / or can receive power from the grid 2408 and output the power to the LODES system 2404. The wind farm 2402, the LODES system 2404, and the transmission facility 2406 can together comprise a power plant 2400, which may be a combined power, transmission, and storage system. Power generated by the wind farm 2402 may be fed directly to the grid 2408 via the transmission facility 2406 or may first be stored in the LODES system 2404. In certain cases, the power supplied to the power grid 2408 may be provided entirely from the wind farm 2402, entirely from the LODES system 2404, or from a combination of the wind farm 2402 and the LODES system 2404.The distribution of power from the combined wind farm 2402 and LODES system 2404 power plant 2400 may be controlled according to a predetermined long-term (multi-day or even multi-year) schedule, or may be controlled according to a day-ahead (24-hour notice) market, or may be controlled according to an hour-ahead market, or may be controlled in response to real-time pricing signals.

[0135] As one example of the operation of the power plant 2400, the LODES system 2404 can be used to reshape and "stabilize" the power produced by the wind farm 2402. In one such example, the wind farm 2402 may have a peak power output (capacity) of 260 megawatts (MW) and a capacity factor (CF) of 41%. The LODES system 2404 may have a power rating (capacity) of 106 MW, a rated duration (energy / power ratio) of 150 hours (h), and a rated energy of 15,900 megawatt hours (MWh). In another such example, the wind farm 2402 may have a peak power output (capacity) of 300 MW and a capacity factor (CF) of 41%. The LODES system 2404 may have a power rating (capacity) of 106 MW, a rated duration (energy / power ratio) of 200 hours, and a rated energy of 21,200 MWh. In another such example, the wind farm 2402 may have a peak power output (capacity) of 176 MW and a capacity factor (CF) of 53%. The LODES system 2404 may have a power rating (capacity) of 88 MW, a rated duration (energy / power ratio) of 150 hours, and a rated energy of 13,200 MWh. In another such example, the wind farm 2402 may have a peak power output (capacity) of 277 MW and a capacity factor (CF) of 41%. The LODES system 2404 may have a power rating (capacity) of 97 MW, a rated duration (energy / power ratio) of 50 hours, and a rated energy of 4,850 MWh. In another such example, the wind farm 2402 may have a peak power output (capacity) of 315 MW and a capacity factor (CF) of 41%. The LODES system 2404 may have a power rating (capacity) of 110 MW, a rated duration (energy / power ratio) of 25 hours, and a rated energy of 2,750 MWh.

[0136] FIG. 23 illustrates an exemplary system in which one or more aspects of the various embodiments may be used as part of a bulk energy storage system. As a specific example, a bulk energy storage system incorporating one or more aspects of the various embodiments may be a LODES system 2404. As an example, the LODES system 2404 may include various embodiment batteries described herein, various electrodes described herein, and the like. The system of FIG. 24 may be similar to the system of FIG. 22, except that a photovoltaic (PV) station 2502 may be used instead of the wind power station 2402. The LODES system 2404 may be electrically connected to the PV station 2502 and one or more transmission facilities 2406. The PV station 2502 may be electrically connected to the transmission facility 2406. The transmission facility 2406 may be electrically connected to the power grid 2408. The PV station 2502 may generate power, and the PV station 2502 may output the generated power to the LODES system 2404 and / or the transmission facility 2406. The LODES system 2404 can store power received from the PV station 2502 and / or the transmission facility 2406. The LODES system 2404 can output the stored power to the transmission facility 2406. The transmission facility 2406 can output power received from one or both of the PV station 2502 and the LODES system 2404 to the grid 2408 and / or can receive power from the grid 2408 and output the power to the LODES system 2404. The PV station 2502, the LODES system 2404, and the transmission facility 2406 together can comprise a power plant 2500, which may be a combined power, transmission, and storage system. Power generated by the PV station 2502 may be fed directly to the grid 2408 via the transmission facility 2406 or may first be stored in the LODES system 2404. In certain cases, the power supplied to the power grid 2408 may be provided entirely from the PV stations 2502, entirely from the LODES systems 2404, or from a combination of the PV stations 2502 and the LODES systems 2404.The distribution of power from the combined PV base 2502 and LODES system 2404 power plant 2500 may be controlled according to a predetermined long-term (multi-day or even multi-year) schedule, or according to a day-ahead (24-hour notice) market, or according to an hour-ahead market, or in response to real-time pricing signals.

[0137] As one example of the operation of the power plant 2500, the LODES system 2404 can be used to reshape and "balance" the power produced by the PV station 2502. In one such example, the PV station 2502 may have a peak power output (capacity) of 490 MW and a capacity factor (CF) of 24%. The LODES system 2404 may have a power rating (capacity) of 340 MW, a rated duration (energy / power ratio) of 150 hours, and a rated energy of 51,000 MWh. In another such example, the PV station 2502 may have a peak power output (capacity) of 680 MW and a capacity factor (CF) of 24%. The LODES system 2404 may have a power rating (capacity) of 410 MW, a rated duration (energy / power ratio) of 200 hours, and a rated energy of 82,000 MWh. In another such example, the PV station 2502 may have a peak power output (capacity) of 330 MW and a capacity factor (CF) of 31%. The LODES system 2404 may have a power rating (capacity) of 215 MW, a rated duration (energy / power ratio) of 150 hours, and a rated energy of 32,250 MWh. In another such example, the PV station 2502 may have a peak power output (capacity) of 510 MW and a capacity factor (CF) of 24%. The LODES system 2404 may have a power rating (capacity) of 380 MW, a rated duration (energy / power ratio) of 50 hours, and a rated energy of 19,000 MWh. In another such example, the PV station 2502 may have a peak power output (capacity) of 630 MW and a capacity factor (CF) of 24%. The LODES system 2404 may have a power rating (capacity) of 380 MW, a rated duration (energy / power ratio) of 25 hours, and a rated energy of 9,500 MWh.

[0138] FIG. 24 illustrates an exemplary system in which one or more aspects of the various embodiments can be used as part of a bulk energy storage system. As a specific example, the bulk energy storage system incorporating one or more aspects of the various embodiments may be a LODES system 2404. As an example, the LODES system 2404 may include various embodiment batteries described herein, various electrodes described herein, and the like. The system of FIG. 24 may be similar to the systems of FIG. 22 and FIG. 23, except that the wind farm 2402 and the photovoltaic (PV) farm 2502 may both be power generating devices operating together in a power plant 2600. The PV farm 2502, the wind farm 2402, the LODES system 2404, and the transmission facility 2406 together may comprise a power plant 2600, which may be a combined power generation, transmission, and storage system. Electricity generated by the PV sites 2502 and / or wind farms 2402 may be delivered directly to the grid 2408 via the transmission facility 2406 or may first be stored in the LODES system 2404. In certain cases, the electricity provided to the grid 2408 may be delivered entirely from the PV sites 2502, entirely from the wind farms 2402, entirely from the LODES system 2404, or from a combination of the PV sites 2502, the wind farms 2402, and the LODES system 2404. The delivery of electricity from the combined wind farms 2402, the PV sites 2502, and the LODES system 2404 power plant 2600 may be controlled according to a predetermined long-term (multi-day or even multi-year) schedule, or according to a day-ahead (24-hour notice) market, or according to an hour-ahead market, or in response to real-time pricing signals.

[0139] As one example of the operation of the power plant 2600, the LODES system 2404 may be used to reshape and "stabilize" the power produced by the wind farm 2402 and the PV farm 2502. In one such example, the wind farm 2402 may have a peak power output (capacity) of 126 MW and a capacity factor (CF) of 41%, and the PV farm 2502 may have a peak power output (capacity) of 126 MW and a capacity factor (CF) of 24%. The LODES system 2404 may have a power rating (capacity) of 63 MW, a rated duration (energy / power ratio) of 150 hours, and a rated energy of 9,450 MWh. In another such example, the wind farm 2402 may have a peak power output (capacity) of 170 MW and a capacity factor (CF) of 41%, and the PV farm 2502 may have a peak power output (capacity) of 110 MW and a capacity factor (CF) of 24%. The LODES system 2404 may have a power rating (capacity) of 57 MW, a rated duration (energy / power ratio) of 200 hours, and a rated energy of 11,400 MWh. In another such example, the wind farm 2402 may have a peak power output (capacity) of 105 MW and a capacity factor (CF) of 51%, and the PV farm 2502 may have a peak power output (capacity) of 70 MW and a capacity factor (CF) of 31. The LODES system 2404 may have a power rating (capacity) of 61 MW, a rated duration (energy / power ratio) of 150 hours, and a rated energy of 9,150 MWh. In another such example, the wind farm 2402 may have a peak power output (capacity) of 135 MW and a capacity factor (CF) of 41%, and the PV farm 2502 may have a peak power output (capacity) of 90 MW and a capacity factor (CF) of 24%. The LODES system 2404 may have a power rating (capacity) of 68 MW, a rated duration (energy / power ratio) of 50 hours, and a rated energy of 3,400 MWh. In another such example, the wind farm 2402 may have a peak power output (capacity) of 144 MW and a capacity factor (CF) of 41%, and the PV farm 2502 may have a peak power output (capacity) of 96 MW and a capacity factor (CF) of 24%.The LODES system 2404 may have a power rating (capacity) of 72 MW, a rated duration (energy / power ratio) of 25 hours, and a rated energy of 1,800 MWh.

[0140] FIG. 25 illustrates an exemplary system in which one or more aspects of the various embodiments can be used as part of a bulk energy storage system. As a specific example, the bulk energy storage system incorporating one or more aspects of the various embodiments may be a LODES system 2404. As an example, the LODES system 2404 may include various embodiment batteries described herein, various electrodes described herein, etc. The LODES system 2404 may be electrically connected to one or more transmission facilities 2406. In this manner, the LODES system 2404 may operate in a "standalone" manner to arbitrate energy near market prices and / or avoid transmission constraints. The LODES system 2404 may be electrically connected to one or more transmission facilities 2406. The transmission facilities 2406 may be electrically connected to a distribution grid 2408. The LODES system 2404 may store power received from the transmission facilities 2406. The LODES system 2404 may output the stored power to the transmission facilities 2406. The power transmission facility 2406 may output power received from the LODES system 2404 to the power distribution grid 2408 and / or may receive power from the power distribution grid 2408 and output the power to the LODES system 2404.

[0141] The LODES system 2404 and the transmission facility 2406 together can constitute a power generation plant 900. As an example, the power generation plant 900 may be located downstream of the transmission constraints, close to the power consumption. In such an exemplary downstream power generation plant 2700, the LODES system 2404 may have a duration of 24 to 500 hours and may perform full discharges once or multiple times per year to support peak power consumption at times when the transmission capacity is not sufficient to serve customers. In addition, in such an exemplary downstream power generation plant 2700, the LODES system 2404 may perform several shallow discharges (daily or more frequently) to arbitrage the difference between nighttime and daytime electricity prices and reduce the overall cost of electricity service to customers. As a further example, the power generation plant 2700 may be located upstream of the transmission constraints, close to the power generation. In such an exemplary upstream power plant 2700, the LODES system 2404 may have a duration of 24 hours to 500 hours and may fully charge once or multiple times per year to absorb excess generation at times when transmission capacity is insufficient to distribute electricity to customers. In addition, in such an exemplary upstream power plant 2700, the LODES system 2404 may shallowly charge and discharge several times (daily or more frequently) to arbitrage the difference between nighttime and daytime electricity prices and maximize the value of the power generation facility's output.

[0142] FIG. 26 illustrates an exemplary system in which one or more aspects of the various embodiments may be used as part of a bulk energy storage system. As a specific example, a bulk energy storage system incorporating one or more aspects of the various embodiments may be a LODES system 2404. As an example, the LODES system 2404 may include the batteries of the various embodiments described herein, the various electrodes described herein, and the like. The LODES system 2404 may be electrically connected to commercial and industrial (C&I) customers 2802, such as data centers, factories, and the like. The LODES system 2404 may be electrically connected to one or more transmission facilities 2406. The transmission facilities 2406 may be electrically connected to a distribution grid 2408. The transmission facilities 2406 may receive power from the distribution grid 2408 and output the power to the LODES system 2404. The LODES system 2404 may store the power received from the transmission facilities 2406. The LODES system 2404 may output the stored power to the C&I customers 2802. In this manner, the LODES system 2404 can operate to reshape the power purchased from the grid 2408 to match the consumption patterns of the C&I customers 2802 .

[0143] The LODES system 2404 and the transmission facility 2406 together may comprise a power generation plant 2800. As an example, the power generation plant 2800 may be located near the electricity consumption, i.e., near the C&I customers 2802, such as between the power distribution grid 2408 and the C&I customers 2802. In such an example, the LODES system 2404 may have a duration of 24 hours to 500 hours and may purchase power from the market at a time when power is cheaper, thereby charging the LODES system 2404. The LODES system 2404 may then discharge and provide power to the C&I customers 2802 at a time when the market price is higher, thus offsetting the market purchases of the C&I customers 2802. As an alternative configuration, the power generation plant 2800 may be located not between the power distribution grid 2408 and the C&I customers 2802, but between a renewable resource, such as a PV site, a wind farm, etc., and the transmission facility 2406, which may be connected to the renewable resource. In such an alternative example, the LODES system 2404 may have a duration between 24 hours and 500 hours, and the LODES system 2404 may be charged at a time when renewable output may be available. The LODES system 2404 may then discharge to cover some or all of the C&I customers 2802's power needs and provide the C&I customers 2802 with renewable generated electricity.

[0144] FIG. 27 illustrates an exemplary system in which one or more aspects of the various embodiments may be used as part of a bulk energy storage system. As a specific example, a bulk energy storage system incorporating one or more aspects of the various embodiments may be a LODES system 2404. As an example, the LODES system 2404 may include the batteries of the various embodiments described herein, the various electrodes described herein, and the like. The LODES system 2404 may be electrically connected to a wind farm 2402 and one or more transmission facilities 2406. The wind farm 2402 may be electrically connected to the transmission facility 2406. The transmission facility 2406 may be electrically connected to a C&I customer 2802. The wind farm 2402 may generate power, and the wind farm 2402 may output the generated power to the LODES system 2404 and / or the transmission facility 2406. The LODES system 2404 may store the power received from the wind farm 2402.

[0145] The LODES system 2404 can output the stored power to the transmission facility 2406. The transmission facility 2406 can output the power received from one or both of the wind farm 2402 and the LODES system 2404 to the C&I customers 2802. The wind farm 2402, the LODES system 2404, and the transmission facility 2406 together can comprise a power plant 2900, which can be a combined generation, transmission, and storage system. The power generated by the wind farm 2402 can be delivered directly to the C&I customers 2802 via the transmission facility 2406, or can be stored in the LODES system 2404 first. In certain cases, the power provided to the C&I customers 2802 can be delivered entirely from the wind farm 2402, entirely from the LODES system 2404, or from a combination of the wind farm 2402 and the LODES system 2404. The LODES system 2404 may be used to reshape electricity generated by the wind farm 2402 to match the consumption patterns of the C&I customers 2802. In one such example, the LODES system 2404 may have a duration of 24 hours to 500 hours and may charge when renewable generation by the wind farm 2402 exceeds the C&I customers 2802 loads. The LODES system 2404 may then discharge when renewable generation by the wind farm 2402 falls below the C&I customers 2802 loads to provide the C&I customers 2802 with a stable renewable profile that offsets some or all of the C&I customers 2802 electricity consumption.

[0146] FIG. 28 illustrates an exemplary system in which one or more aspects of the various embodiments can be used as part of a bulk energy storage system. As a specific example, the bulk energy storage system incorporating one or more aspects of the various embodiments can be a LODES system 2404. As an example, the LODES system 2404 can include the batteries of the various embodiments described herein, the various electrodes described herein, and the like. The LODES system 2404 can be part of a power plant 3000 that is used to integrate large amounts of renewable generation into a microgrid, for example, to match the output of renewable generation by the PV site 2502 and the wind power site 2402 with existing thermal generation by, for example, a thermal power plant 3002 (e.g., a gas plant, a coal plant, a diesel generator set, etc., or a combination of thermal generation methods), and provide renewable and thermal generation to C&I customer 2802 loads when availability is high. A microgrid such as the microgrid composed of the power plant 3000 and the thermal power plant 3002 can provide an availability of 90% or higher. Electricity generated by the PV site 2502 and / or wind farm 2402 may be delivered directly to C&I customers 2802 or may first be stored in the LODES system 2404 .

[0147] In a particular case, the power provided to the C&I customers 2802 may be entirely from the PV sites 2502, entirely from the wind farms 2402, entirely from the LODES systems 2404, entirely from the thermal power plants 3002, or any combination of the PV sites 2502, the wind farms 2402, the LODES systems 2404, and / or the thermal power plants 3002. As an example, the LODES systems 2404 of the power plant 3000 may have a duration of 24 hours to 500 hours. As a specific example, the C&I customers 2802 load may be 100 MW peak, the LODES systems 2404 may have a power rating of 14 MW and a duration of 150 hours, the cost of natural gas may be $6 / million British thermal units (MMBTU), and the renewable occupancy may be 58%. As another specific example, the C&I customer 2802 load may be 100 MW peak, the LODES system 2404 may have a power rating of 25 MW and a duration of 150 hours, the cost of natural gas may be $8 / million British thermal units (MMBTU), and the renewable occupancy may be 65%.

[0148] FIG. 29 illustrates an exemplary system in which one or more aspects of the various embodiments can be used as part of a bulk energy storage system. As a specific example, the bulk energy storage system incorporating one or more aspects of the various embodiments may be a LODES system 2404. As an example, the LODES system 2404 may include the batteries of the various embodiments described herein, the various electrodes described herein, and the like. The LODES system 2404 can be used to enhance the nuclear power plant 3102 (or other inflexible power generation facilities such as thermal, biomass, and / or any other type of power plant with a ramp rate of less than 50% of rated power in one hour and a capacity factor of 80% or higher) to add flexibility to the combined output of the power plant 3100 composed of the combined LODES system 2404 and the nuclear power plant 3102. The nuclear power plant 3102 can be operated at a high capacity factor and at its highest efficiency point, and the LODES system 2404 can be charged and discharged to effectively reshape the output of the nuclear power plant 3102 to match customer electricity consumption and / or the market price of electricity. As an example, the LODES system 2404 of the power plant 3100 may have a duration of 24 hours to 500 hours. In one specific example, the nuclear power plant 3102 may have a rated power output of 1,000 MW, and the nuclear power plant 3102 may be forced to operate at minimum stable power generation or even shut down for long periods of time due to a drop in the market price of electricity. The LODES system 2404 can charge to avoid a facility shutdown when the market price drops, and then the LODES system 2404 can discharge when the market price rises, increasing the total power generation.

[0149] FIG. 30 illustrates an exemplary system in which one or more aspects of the various embodiments can be used as part of a bulk energy storage system. As a specific example, the bulk energy storage system incorporating one or more aspects of the various embodiments may be a LODES system 2404. As an example, the LODES system 2404 may include various embodiment batteries described herein, various electrodes described herein, and the like. The LODES system 2404 may operate in conjunction with an SDES system 3202. The LODES system 2404 and the SDES system 3202 together may comprise a power plant 3200. As an example, the LODES system 2404 and the SDES system 3202 may be co-optimized, such that the LODES system 2404 can provide various services including long-term backup and / or bridging over multi-day variations (e.g., multi-day variations in market prices, renewable generation, electricity consumption, and the like). The SDES system 3202 can provide various services including rapid support services (e.g., voltage control, frequency regulation, etc.) and / or bridging across diurnal variations (e.g., diurnal variations in market prices, renewable generation, electricity consumption, etc.). The SDES system 3202 may have a duration of less than 10 hours and a round trip efficiency of greater than 80%. The LODES system 2404 may have a duration of 24 hours to 500 hours and a round trip efficiency of greater than 40%. In one such example, the LODES system 2404 may have a duration of 150 hours and can support customer electricity consumption for up to one week of renewable generation shortage. The LODES system 2404 can also support customer electricity consumption during a diurnal generation shortage event to enhance the capacity of the SDES system 3202. Additionally, the SDES system 3202 can power customers during a diurnal generation shortage event and provide quality services such as power conditioning and voltage control and frequency regulation.

[0150] Various embodiments may include an electrode assembly including: a first electrode on a first side of the electrode assembly, the first electrode including a planar portion adjacent a bottom periphery and first and second lateral peripheries of the electrode assembly and a convex portion extending from the planar portion to a raised portion of the first electrode located in a central region of the electrode assembly and extending to a top periphery; and a second member on a second side of the electrode assembly opposite the first side, the planar portion of the first electrode contacting and sealed to a surface of the second member, the electrode assembly comprising an interior chamber defined between an inner surface of the first electrode and an inner surface of the second member. In some embodiments, the second member comprises a second electrode on a second side of the electrode assembly, the second electrode comprising a planar portion adjacent the bottom periphery and the first and second lateral peripheries of the electrode assembly, and a convex portion extending from the planar portion to a raised portion of the second electrode located in a central region of the second electrode and extending to the top periphery of the electrode assembly. In some embodiments, the first electrode and the second electrode each comprise an oxygen reduction reaction (ORR) electrode. In some embodiments, the first electrode and the second electrode each comprise a laminated gas diffusion (GD) electrode comprising an active layer and at least one backing layer. In some embodiments, the active layer of the first electrode and the second electrode comprises a hydrophilic surface, and the backing layer of the first electrode and the second electrode comprises a hydrophobic surface. In some embodiments, the first electrode and the second electrode each comprise a laminated gas diffusion (GD) electrode having an embedded current collector. In some embodiments, the current collector is in electrical contact with a bus bar located within the interior chamber of the electrode assembly. In some embodiments, the active layers of the first electrode and the second electrode are located on respective outer surfaces of the electrode assembly. In some embodiments, the active layers of the first electrode and the second electrode do not extend to the bottom peripheral edge and the first and second lateral peripheral edges of the electrode assembly.In some embodiments, the active layers of the first and second electrodes do not extend to the top peripheral edge of the electrode assembly, and each of the laminated gas diffusion electrodes includes a strip of electrochemically inactive material located between the top edge of the respective active layers and the top peripheral edge of the electrode assembly. In some embodiments, the electrode assembly further includes an insert located within the interior chamber of the electrode assembly and in contact with the backing layers of each of the first and second electrodes, the insert defining an air flow field across the backing layers of each of the first and second electrodes. In some embodiments, the raised central region of the first electrode has a textured, undulating, and / or roughened three-dimensional shape. In some embodiments, the electrode assembly may further include a sealant material located between the planar portion of the first electrode and the surface of the second member. In some embodiments, the sealant material includes at least one of a thermoplastic material, a fluorinated ethylene propylene (FEP), a polytetrafluoroethylene (PTFE), an epoxy material, or a hot melt adhesive material. In some embodiments, the electrode assembly further comprises a sealant material on the bottom peripheral edge and the first and second side peripheral edges of the electrode assembly. In some embodiments, the sealant material comprises at least one of an epoxy paint, an epoxy dose, an epoxy dip seal, a clip, a clamp, and an epoxy lined tape. In some embodiments, the second side of the electrode assembly comprises a planar surface. In some embodiments, the second member comprises a support substrate comprised of an electrochemically inactive material. Some embodiments may include a battery comprising: a housing; a liquid electrolyte within the housing; an anode electrode within the housing and at least partially immersed in the liquid electrolyte; and an electrode assembly according to any one or more of the embodiments described in this paragraph, the electrode assembly within the housing and at least partially immersed in the liquid electrolyte.

[0151] Various embodiments may include a method of manufacturing an electrode assembly, the method including: providing a layer stack including at least one active layer and at least one backing layer; applying pressure and heat to the layer stack to form a laminated gas diffusion electrode, the laminated gas diffusion electrode including a planar portion adjacent a bottom peripheral edge and first and second lateral peripheral edges of the electrode and a convex portion extending from the planar portion to a raised portion of the electrode located in a central region of the electrode and extending to a top peripheral edge of the electrode; and bonding the laminated gas diffusion electrode to a second member to seal the planar portion against the second member to form an electrode assembly having an interior chamber between the laminated gas diffusion electrode and the second member. In some embodiments, the laminated gas diffusion electrode includes a first laminated gas diffusion electrode and the second member includes a second laminated gas diffusion electrode. In some embodiments, the method further includes providing a second layer stack including at least one active layer and at least one backing layer; and applying pressure and heat to the second layer stack to form a second laminated gas diffusion electrode, the second laminated gas diffusion electrode including a planar portion adjacent a bottom peripheral portion and first and second lateral peripheral portions of the second laminated gas diffusion electrode, and a convex portion extending from the planar portion to a raised portion of the second laminated gas diffusion electrode located in a central region of the second laminated gas diffusion electrode and extending adjacent a top peripheral portion, and bonding the first laminated gas diffusion electrode to the second laminated gas diffusion electrode includes forming a seal between the planar portion of the first laminated gas diffusion electrode and the planar portion of the second laminated gas diffusion electrode to form an electrode assembly having an internal chamber between the first laminated gas diffusion electrode and the second laminated gas diffusion electrode. In some embodiments, the first and second laminated gas diffusion electrodes are formed and joined simultaneously. In some embodiments, the first and second laminated gas diffusion electrodes are formed and joined by placing the first layer stack and the second layer stack in a mold apparatus and hot pressing the first layer stack and the second layer stack in the mold apparatus to provide an electrode assembly including the first laminated gas diffusion electrode joined to the second laminated gas diffusion electrode.In some embodiments, the step of bonding the first laminated gas diffusion electrode to the second laminated gas diffusion electrode comprises: placing the first laminated gas diffusion electrode and the second laminated gas diffusion electrode in a mechanical press; and applying mechanical pressure and heat to the planar portions of the first laminated gas diffusion electrode and the second laminated gas diffusion electrode using the mechanical press to form the seal between the planar portion of the first laminated gas diffusion electrode and the planar portion of the second laminated gas diffusion electrode. In some embodiments, the first laminated gas diffusion electrode and the second laminated gas diffusion electrode are formed on a continuous sheet that is assembled and sealed along at least the first and second lateral surfaces of the electrodes.

[0152] Various embodiments may include a method of manufacturing an electrode assembly, comprising: sealing a first laminated gas diffusion electrode to one or more side walls of a support frame on a first side of the support frame such that the first laminated gas diffusion electrode extends onto a first side of an open area within the one or more side walls; and sealing a second laminated gas diffusion electrode to one or more side walls on a second side of the support frame such that the second laminated gas diffusion electrode extends onto a second side of an open area within the one or more side walls. In some embodiments, the first and second laminated gas diffusion electrodes are sealed to the side walls under a negative pressure environment to promote wetting of a sealant material into the pores of the first and second laminated gas diffusion electrodes. Various embodiments may include a method for manufacturing a large area laminated gas diffusion electrode comprising: folding laminated portions of a first layer stack and a second layer stack to provide interconnecting side edges of the first layer stack and the second layer stack, each layer stack including at least one active layer and at least one backing layer; and applying pressure and heat to the interconnecting side edges to bond the interconnecting side edges to form a paired seam of the first layer stack and the second layer stack.

[0153] Various embodiments may include a method for manufacturing an electrode assembly, the method including: providing a first layer stack including at least one active layer and at least one backing layer, and a second layer stack including at least one active layer and at least one backing layer; applying pressure and heat to the first layer stack to form a first laminated gas diffusion electrode and applying pressure and heat to the second layer stack to form a second laminated gas diffusion electrode; bonding the first laminated gas diffusion electrode to the second laminated gas diffusion electrode to form an electrode assembly having a spacer between the first and second laminated gas diffusion electrodes; and removing the spacer from the electrode assembly to provide a cavity between the first and second laminated gas diffusion electrodes of the electrode assembly.

[0154] In some embodiments, the first and second laminated gas diffusion electrodes are formed and bonded simultaneously, the method includes placing the first layer stack, the second layer stack, and a spacer in a heat press such that the spacer is located between the first layer stack and the second layer stack, the heat press being used to apply sufficient heat and pressure to simultaneously form and bond the first and second laminated gas diffusion electrodes. In some embodiments, the method further includes placing the first laminated gas diffusion electrode, the second laminated gas diffusion electrode, and a spacer in a heat press such that the spacer is located between the first laminated gas diffusion electrode and the second laminated gas diffusion electrode, the heat press being used to apply sufficient heat and pressure to bond the first laminated gas diffusion electrode to the second laminated gas diffusion electrode. Various embodiments may include an electrode assembly including a support frame having one or more side walls surrounding an outer periphery of the support frame and surrounding an interior open area of ​​the one or more side walls; a first laminated gas diffusion electrode sealed to the one or more side walls of the support frame on a first side of the support frame; and a second laminated gas diffusion electrode sealed to the one or more side walls of the support frame on an opposite side of the support frame. In some embodiments, the first and second laminated gas diffusion electrodes are sealed to each of the first and opposite sides using a first sealant material without heat treatment. In some embodiments, the first and second laminated gas diffusion electrodes are sealed to each of the first and opposite sides using a first sealant material with heat treatment.

[0155] In some embodiments, one or more support walls of the support frame include acrylonitrile butadiene styrene (ABS), and the first sealant material includes ABS cement. In some embodiments, the one or more side walls have three H-channel structures configured to form at least three sides of a rectangle. In some embodiments, the rectangle includes an open area configured to receive an insert that defines at least one flow field for one or more of the first laminated gas diffusion electrode and the second laminated gas diffusion electrode. In some embodiments, the H-channel structures are configured to receive a second sealant material. In some embodiments, the second sealant material includes an epoxy. In some embodiments, each of the first and second laminated gas diffusion electrodes includes at least one active layer, at least one backing layer, and an embedded current collector. Some embodiments may include a battery including: a housing; a liquid electrolyte within the housing; an anode electrode within the housing and at least partially immersed in the liquid electrolyte; and an electrode assembly according to any one or more of the embodiments described in this paragraph, the electrode assembly within the housing and at least partially immersed in the liquid electrolyte.

[0156] The above method descriptions are provided only as illustrative examples and are not intended to require or imply that the steps of the various embodiments must be performed in the order presented. As one skilled in the art would understand, the order of steps in the above embodiments may be performed in any order. Words such as "then," "then," and "next" are not necessarily intended to limit the order of steps, and such words may be used to guide the reader through the method description. Additionally, any reference to a claim element in the singular, for example, using "a," "an," or "said," (the article "a," "an," or "the"), should not be construed as limiting the element to the singular.

[0157] Furthermore, any step of any embodiment described herein can be used in any other embodiment. The foregoing description of the aspects of the present disclosure 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 basic principles defined herein can be applied to other aspects without departing from the scope of the present invention. Thus, the present invention is not intended to be limited to the aspects shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. 1. An electrode assembly comprising: a first electrode on a first side and a second member on a second side opposite the first side; the first electrode includes a planar portion adjacent a bottom periphery and first and second lateral peripheries of the electrode assembly, and a convex portion extending from the planar portion to a raised portion of the first electrode located in a central region of the electrode assembly and extending to a top periphery; the planar portion of the first electrode contacts and is sealed to a surface of the second member, the electrode assembly comprising an interior chamber defined between an interior surface of the first electrode and an interior surface of the second member; Electrode assembly.

2. 2. The electrode assembly of claim 1, wherein the second member comprises a second electrode on the second side of the electrode assembly, the second electrode including a planar portion adjacent the bottom periphery and the first and second lateral peripheries of the electrode assembly, and a convex portion extending from the planar portion to a raised portion of the second electrode located in a central region of the second electrode and extending to the top periphery of the electrode assembly.

3. The electrode assembly of claim 2 , wherein the first electrode and the second electrode each comprise an oxygen reduction reaction (ORR) electrode.

4. 3. The electrode assembly of claim 2, wherein the first electrode comprises a first laminated gas diffusion (GD) electrode comprising an active layer and at least one backing layer, and the second electrode comprises a second laminated gas diffusion electrode comprising an active layer and at least one backing layer.

5. 5. The electrode assembly of claim 4, wherein the active layer of the first electrode and the active layer of the second electrode comprise a hydrophilic surface, and the at least one backing layer of the first electrode and the at least one backing layer of the second electrode comprise a hydrophobic surface.

6. 5. The electrode assembly of claim 4, wherein the first electrode and the second electrode each comprise a laminated gas diffusion (GD) electrode having an embedded current collector.

7. 7. The electrode assembly of claim 6, wherein the embedded current collector electrically contacts a bus bar located within the interior chamber of the electrode assembly.

8. The electrode assembly of claim 4 , wherein the active layer of the first electrode and the active layer of the second electrode are located on respective outer surfaces of the electrode assembly.

9. 5. The electrode assembly of claim 4, wherein the active layer of the first electrode and the active layer of the second electrode do not extend to the bottom periphery and the first and second lateral peripheries of the electrode assembly.

10. 10. The electrode assembly of claim 9, wherein the active layer of the first electrode and the active layer of the second electrode do not extend to the top peripheral edge of the electrode assembly, and each of the first and second laminated gas diffusion electrodes includes a strip of electrochemically inactive material located between an upper edge of the respective active layer and the top peripheral edge of the electrode assembly.

11. 5. The electrode assembly of claim 4, further comprising an insert located within the interior chamber of the electrode assembly and contacting a backing layer of each of the first electrode and the second electrode, the insert defining an air flow field across the backing layers of the first electrode and the second electrode.

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

13. The electrode assembly of claim 1 , further comprising a sealant material positioned between the planar portion of the first electrode and the surface of the second member.

14. 14. The electrode assembly of claim 13, wherein the sealant 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 , further comprising a sealant material on the bottom periphery and the first and second lateral peripheries of the electrode assembly.

16. 16. The electrode assembly of claim 15, wherein the sealant material is at least one of an epoxy paint, an epoxy dose, an epoxy dip seal, a clip, a clamp, and an epoxy lined tape.

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

18. 18. The electrode assembly of claim 17, wherein the second member comprises a supporting substrate constructed of an electrochemically inactive material.

19. A battery, Housing and a liquid electrolyte within the housing; an anode electrode within the housing and at least partially immersed in the liquid electrolyte; 10. The electrode assembly of claim 1 within the housing and at least partially immersed in the liquid electrolyte; Including batteries.

20. 1. A method for manufacturing an electrode assembly, comprising: providing a first layer stack including at least one active layer and at least one backing layer; applying pressure and heat to the first layer stack to form a laminated gas diffusion electrode, the laminated gas diffusion electrode including a planar portion adjacent a bottom peripheral edge and first and second lateral peripheral edges of the electrode assembly, and a convex portion extending from the planar portion to a raised portion of the electrode assembly located in a central region of the electrode assembly and extending to a top peripheral edge; bonding the laminated gas diffusion electrode to a second member and sealing the planar portion to the second member to form the electrode assembly having an interior chamber between the laminated gas diffusion electrode and the second member; A method comprising:

21. 21. The method of claim 20, wherein the laminated gas diffusion electrode comprises a first laminated gas diffusion electrode and the second member comprises a second laminated gas diffusion electrode.

22. providing a second layer stack including at least one active layer and at least one backing layer; applying pressure and heat to the second layer stack to form the second laminated gas diffusion electrode, the second laminated gas diffusion electrode including a flat portion adjacent to a bottom peripheral edge and first and second lateral peripheral edges of the second laminated gas diffusion electrode, and a convex portion extending from the flat portion to a raised portion of the second laminated gas diffusion electrode located in a central region of the second laminated gas diffusion electrode and extending adjacent to a top peripheral edge, and bonding the first laminated gas diffusion electrode to the second laminated gas diffusion electrode includes forming a seal between the flat portion of the first laminated gas diffusion electrode and the flat portion of the second laminated gas diffusion electrode to form an electrode assembly having an internal chamber between the first laminated gas diffusion electrode and the second laminated gas diffusion electrode.

22. The method of claim 21.

23. 23. The method of claim 22, wherein the first and second laminated gas diffusion electrodes are formed and bonded simultaneously.

24. 23. The method of claim 22, wherein the first and second laminated gas diffusion electrodes are formed and joined by placing the first layer stack and the second layer stack in a mold apparatus and hot-pressing the first layer stack and the second layer stack in the mold apparatus to provide the electrode assembly comprising the first laminated gas diffusion electrode joined to the second laminated gas diffusion electrode.

25. The step of joining the first laminated-structure gas diffusion electrode to the second laminated-structure gas diffusion electrode includes: placing the first stacked gas diffusion electrode and the second stacked gas diffusion electrode in a mechanical press; applying mechanical pressure and heat to the planar portion of the first laminated gas diffusion electrode and the planar portion of the second laminated gas diffusion electrode using the mechanical press to form the seal between the planar portion of the first laminated gas diffusion electrode and the planar portion of the second laminated gas diffusion electrode; 23. The method of claim 22, comprising:

26. 1. A method for manufacturing an electrode assembly, comprising: sealing a first laminated gas diffusion electrode to one or more side walls of a support frame on a first side of the support frame so that the first laminated gas diffusion electrode extends onto a first side of an open area within the one or more side walls; sealing a second laminated gas diffusion electrode to the one or more side walls on a second side of the support frame so that the second laminated gas diffusion electrode extends onto a second side of the open area within the one or more side walls; A method comprising:

27. 27. The method of claim 26, wherein the first and second stacked gas diffusion electrodes are sealed against the sidewalls under a negative pressure environment to promote wetting of a sealant material into pores of the first and second stacked gas diffusion electrodes.

28. A method for manufacturing a large-area laminated gas diffusion electrode, comprising: folding laminated portions of a first layer stack and a second layer stack to provide interconnecting side edges of the first layer stack and the second layer stack, each layer stack including at least one active layer and at least one backing layer; applying pressure and heat to the interconnecting side edges to join the interconnecting side edges to form a paired seam of the first layer stack and the second layer stack; A method comprising:

29. 1. A method of manufacturing an electrode assembly, comprising: providing a first layer stack including at least one active layer and at least one backing layer, and a second layer stack including at least one active layer and at least one backing layer; applying pressure and heat to the first layer stack to form a first laminated gas diffusion electrode and applying pressure and heat to the second layer stack to form a second laminated gas diffusion electrode; bonding the first stacked gas diffusion electrode to the second stacked gas diffusion electrode to form an electrode assembly having a spacer between the first stacked gas diffusion electrode and the second stacked gas diffusion electrode; removing the spacer from the electrode assembly to provide a cavity between the first stacked gas diffusion electrode and the second stacked gas diffusion electrode of the electrode assembly; A method comprising:

30. The first and second laminated gas diffusion electrodes are formed and bonded simultaneously, and placing the first layer stack, the second layer stack, and the spacer in a heat press apparatus such that the spacer is located between the first layer stack and the second layer stack, the heat press apparatus being used to apply heat and pressure sufficient to simultaneously form and bond the first and second laminated gas diffusion electrodes; 30. The method of claim 29.

31. and placing the first laminated gas diffusion electrode, the second laminated gas diffusion electrode, and the spacer in a heat press device such that the spacer is located between the first laminated gas diffusion electrode and the second laminated gas diffusion electrode, the heat press device being used to apply heat and pressure sufficient to bond the first laminated gas diffusion electrode to the second laminated gas diffusion electrode.

30. The method of claim 29.

32. 1. An electrode assembly comprising: a support frame having one or more side walls surrounding an outer periphery of the support frame and enclosing an interior open area of ​​the one or more side walls; a first laminated gas diffusion electrode on a first surface of the support frame and sealed to the one or more side walls of the support frame; a second laminated gas diffusion electrode sealed to the one or more side walls of the support frame on an opposite side of the support frame; an electrode assembly comprising:

33. 33. The electrode assembly of claim 32, wherein the first and second laminated gas diffusion electrodes are sealed to the first and opposite sides, respectively, using a first sealant material without heat treatment.

34. 34. The electrode assembly of claim 33, wherein the one or more side walls of the support frame comprise acrylonitrile butadiene styrene (ABS) and the first sealant material comprises ABS cement.

35. 34. The electrode assembly of claim 33, wherein the one or more side walls have three H-channel structures configured to form at least three sides of a rectangle.

36. 36. The electrode assembly of claim 35, wherein the rectangle includes an open area configured to receive an insert that defines at least one flow field for one or more of the first and second stacked gas diffusion electrodes.

37. 36. The electrode assembly of claim 35, wherein the H-channel structure is configured to receive a second sealant material.

38. 38. The electrode assembly of claim 37, wherein the second sealant material comprises an epoxy.

39. 33. The electrode assembly of claim 32, wherein each of the first and second laminated gas diffusion electrodes includes at least one active layer, at least one backing layer, and an embedded current collector.

40. 33. The electrode assembly of claim 32, wherein the first and second laminated gas diffusion electrodes are sealed to the first and opposite sides of the support frame, respectively, using a first sealant material and by heat treatment.

41. A battery, Housing and a liquid electrolyte within the housing; an anode electrode within the housing and at least partially immersed in the liquid electrolyte; 33. The electrode assembly of claim 32, located within the housing and at least partially immersed in the liquid electrolyte; Including batteries.

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