Electrode stack for metal hydride battery

Abstract

A metal hydrogen battery is presented. The metal hydrogen batter battery comprises an electrode stack, the electrode stack having alternating anode and cathode assemblies, the anode and cathode assemblies being separated by a separator, each of the anode assemblies including at least one anode layer connected to an anode bus, each of the cathode assemblies including at least one cathode layer connected to a cathode bus, where each of the anode busses are electrically and mechanically attached to form an anode conductor, and where each of the cathode busses are electrically and mechanically attached to form a cathode conductor. The electrode stack is positioned within a pressure vessel, the pressure vessel having a sidewall, a cathode end plate, and an anode end plate. Finally, an electrolyte is contained within the pressure vessel.

Description

[Technical Field]

[0001] [Related Applications] This disclosure claims priority to U.S. Patent Application No. 17 / 687,527, filed March 4, 2022, which is hereby expressly incorporated by reference in its entirety.

[0002] FIELD OF THE INVENTION Embodiments of the present invention relate to metal-hydrogen batteries, and more particularly to the construction of metal-hydrogen batteries. [Background technology]

[0003] For renewable energy sources, such as wind and solar, to be competitive with traditional fossil fuels, large-scale energy storage systems are necessary to reduce their inherent intermittency. To build large-scale energy storage, cost and long-term lifetime are paramount considerations. Pumped hydroelectric storage dominates the current grid energy storage market because it is an inexpensive way to store large amounts of energy for long periods (approximately 50 years), but it is constrained by a lack of suitable locations and its environmental footprint. Other technologies, such as compressed air and flywheel energy storage, offer several distinct advantages, but their relatively low efficiency and high cost must be significantly improved for grid storage. Rechargeable batteries offer a significant opportunity to target low-cost, high-capacity, and highly reliable systems for large-scale energy storage. Improving the reliability of rechargeable batteries has become a key issue for realizing large-scale energy storage.

[0004] Consequently, there is a need for better metal-hydrogen battery configurations. Summary of the Invention

[0005] According to embodiments of the present disclosure, a metal-hydrogen battery is provided. Some embodiments of the metal-hydrogen battery include an electrode stack, the electrode stack having alternating anode and cathode assemblies separated by a separator, each of the anode assemblies including at least one anode layer connected to an anode bus, each of the cathode assemblies including at least one cathode layer connected to a cathode bus, where each of the anode buses is electrically and mechanically attached to form an anode conductor, and where each of the cathode buses is electrically and mechanically attached to form a cathode conductor; a pressure vessel, the pressure vessel having a sidewall, a cathode end plate, and an anode end plate, the electrode stack inserted within the pressure vessel; and an electrolyte contained within the electrode stack.

[0006] A method of forming a metal-hydrogen battery according to some embodiments of the present disclosure comprises pre-assembling components of the metal-hydrogen battery by assembling a plurality of cathode assemblies, each cathode assembly having a cathode bus bar attached to one or more cathode material layers; assembling a plurality of anode assemblies, each anode assembly having an anode bus bar coupled to one or more anode material layers; forming a separator from one or more separator layers; forming a frame inner portion and a frame outer portion, at least one of the frame inner portion and the frame outer portion including a finger connecting the frame inner portion and the frame outer portion; assembling a cathode feedthrough assembly including a bridge welded to a cathode feedthrough conductor; assembling a cathode can assembly including a cathode end cap, a feedthrough connected to the cathode end cap, a fill tube connected to the cathode end cap, and a can sidewall attached to the cathode end cap, the feedthrough including a body and an insulator; and preparing an electrolyte.After the components are pre-assembled, the metal-hydrogen battery may be fabricated by stacking the inner frame portion, the outer frame portion, a separator, an anode assembly, and a cathode assembly in a jig to capture the electrode between the inner frame portion and the outer frame portion; pressing the electrode, the inner frame portion, and the outer frame portion in the jig; attaching the inner frame portion to the outer frame portion using the fingers while pressure is applied to form a frame; attaching the anode bus bars of the plurality of anode assemblies to form anode conductors, and attaching the cathode bus bars of the plurality of cathode assemblies to form cathode conductors, to form an electrode stack; and attaching the anode end cap to the anode end cap of the electrode stack. assembling an anode assembly by attaching an insulator over the cathode feedthrough conductor and attaching the cathode feedthrough assembly to the cathode conductor of the electrode stack; inserting an insulator over the cathode feedthrough conductor; inserting the anode assembly into the can side wall of the cathode can assembly by inserting the cathode feedthrough conductor through the feedthrough in the cathode end cap; attaching the anode end cap of the anode assembly to the can side wall of the cathode can assembly; crushing the body of the feedthrough to seal the insulator of the feedthrough to the cathode feedthrough conductor; adding electrolyte to the electrode stack through the fill tube; and sealing the fill tube.

[0007] 1. An electrode stack for a hydrogen metal battery, comprising: an electrode stack having alternating anode assemblies and cathode assemblies separated by separators, each of the anode assemblies including at least one anode layer connected to an anode bus, each of the cathode assemblies including at least one cathode layer connected to a cathode bus, wherein each of the anode buses is electrically and mechanically attached to form an anode conductor, and wherein each of the cathode buses is electrically and mechanically attached to form a cathode conductor.

[0008] 1. A method for forming an electrode stack for a metal-hydrogen battery, comprising: assembling a plurality of cathode assemblies, each cathode assembly having a cathode bus bar attached to one or more cathode material layers; assembling a plurality of anode assemblies, each anode assembly having an anode bus bar connected to one or more anode material layers; forming a separator from a separator material; forming a frame inner portion and a frame outer portion, at least one of the frame inner portion and the frame outer portion including fingers connecting the frame inner portion and the frame outer portion; forming an electrode stack by: stacking the inner frame portion, the outer frame portion, a separator, an anode assembly, and a cathode assembly to capture the electrode between the inner frame portion and the outer frame portion; pressing the electrode, the inner frame portion, and the outer frame portion; attaching the inner frame portion to the outer frame portion using the fingers while pressure is applied to form a frame, attaching the anode bus bars of the plurality of anode assemblies to form anode conductors, and attaching the cathode bus bars of the plurality of cathode assemblies to form cathode conductors.

[0009] These and other embodiments are discussed below with respect to the following figures. [Brief explanation of the drawings]

[0010] An understanding of the features and advantages of the techniques described in this disclosure will be gained by reference to the following detailed description, which sets forth illustrative embodiments with reference to the following figures.

[0011] [Figure 1] FIG. 1 illustrates an example of a metal-hydrogen battery according to some embodiments of the present disclosure.

[0012] [Figure 2A] FIG. 1 illustrates an example of an electrode stack according to some embodiments of the present disclosure. [Figure 2B] FIG. 1 illustrates an example of an electrode stack according to some embodiments of the present disclosure. [Figure 2C] FIG. 1 illustrates an example of an electrode stack according to some embodiments of the present disclosure. [Figure 2D] FIG. 1 illustrates an example of an electrode stack according to some embodiments of the present disclosure.

[0013] [Figure 3A] FIG. 2 illustrates an example of a separator for an electrode stack, according to some embodiments of the present disclosure. [Figure 3B] FIG. 2 illustrates an example of a separator for an electrode stack, according to some embodiments of the present disclosure. [Figure 3C] FIG. 2 illustrates an example of a separator for an electrode stack, according to some embodiments of the present disclosure.

[0014] [Figure 4A] 3C shows an example of an anode assembly according to an embodiment of the present disclosure that may be used in the electrode stack shown in FIGS. 3A and 3B. FIG. [Figure 4B]3C shows an example of an anode assembly according to an embodiment of the present disclosure that may be used in the electrode stack shown in FIGS. 3A and 3B. FIG. [Figure 4C] 3C shows an example of an anode assembly according to an embodiment of the present disclosure that may be used in the electrode stack shown in FIGS. 3A and 3B. FIG. [Figure 4D] 3C shows an example of an anode assembly according to an embodiment of the present disclosure that may be used in the electrode stack shown in FIGS. 3A and 3B. FIG. [Figure 4E] 3C shows an example of an anode assembly according to an embodiment of the present disclosure that may be used in the electrode stack shown in FIGS. 3A and 3B. FIG. [Figure 4F] 3C shows an example of an anode assembly according to an embodiment of the present disclosure that may be used in the electrode stack shown in FIGS. 3A and 3B. FIG.

[0015] [Figure 5A] 3C illustrates an example of a cathode assembly according to some embodiments of the present disclosure that may be used in the electrode stack illustrated in FIGS. 3A and 3B. FIG. [Figure 5B] 3C illustrates an example of a cathode assembly according to some embodiments of the present disclosure that may be used in the electrode stack illustrated in FIGS. 3A and 3B. FIG. [Figure 5C] 3C illustrates an example of a cathode assembly according to some embodiments of the present disclosure that may be used in the electrode stack illustrated in FIGS. 3A and 3B. FIG. [Figure 5D] 3C illustrates an example of a cathode assembly according to some embodiments of the present disclosure that may be used in the electrode stack illustrated in FIGS. 3A and 3B. FIG. [Figure 5E] 3C illustrates an example of a cathode assembly according to some embodiments of the present disclosure that may be used in the electrode stack illustrated in FIGS. 3A and 3B. FIG. [Figure 5F]3C illustrates an example of a cathode assembly according to some embodiments of the present disclosure that may be used in the electrode stack illustrated in FIGS. 3A and 3B. FIG.

[0016] [Figure 6A] FIG. 2 illustrates an example of an assembly of an electrode stack, according to some embodiments of the present disclosure. [Figure 6B] FIG. 2 illustrates an example of an assembly of an electrode stack, according to some embodiments of the present disclosure. [Figure 6C] FIG. 2 illustrates an example of an assembly of an electrode stack, according to some embodiments of the present disclosure.

[0017] [Figure 7A] FIG. 6B is a diagram showing an example of one of the frames shown in FIGS. 6A, 6B, and 6C. [Figure 7B] FIG. 6B is a diagram showing an example of one of the frames shown in FIGS. 6A, 6B, and 6C. [Figure 7C] FIG. 6B is a diagram showing an example of one of the frames shown in FIGS. 6A, 6B, and 6C. [Figure 7D] FIG. 6B is a diagram showing an example of one of the frames shown in FIGS. 6A, 6B, and 6C. [Figure 7E] FIG. 6B is a diagram showing an example of one of the frames shown in FIGS. 6A, 6B, and 6C. [Figure 7F] FIG. 6B is a diagram showing an example of one of the frames shown in FIGS. 6A, 6B, and 6C. [Figure 7G] FIG. 6B is a diagram showing an example of one of the frames shown in FIGS. 6A, 6B, and 6C. [Figure 7H] FIG. 6B is a diagram showing an example of one of the frames shown in FIGS. 6A, 6B, and 6C.

[0018] [Figure 8A] 1A-1C illustrate an example of a battery assembly according to some aspects of the present disclosure. [Figure 8B]1A-1C illustrate an example of a battery assembly according to some aspects of the present disclosure. [Figure 8C] 1A-1C illustrate an example of a battery assembly according to some aspects of the present disclosure. [Figure 8D] 1A-1C illustrate an example of a battery assembly according to some aspects of the present disclosure. [Figure 8E] 1A-1C illustrate an example of a battery assembly according to some aspects of the present disclosure. [Figure 8F] 1A-1C illustrate an example of a battery assembly according to some aspects of the present disclosure. [Figure 8G] 1A-1C illustrate an example of a battery assembly according to some aspects of the present disclosure.

[0019] [Figure 9A] FIG. 8C shows an example of a cathode bridge used in the battery shown in FIGS. 8A and 8B. [Figure 9B] FIG. 8C shows an example of a cathode bridge used in the battery shown in FIGS. 8A and 8B.

[0020] [Figure 9C] 8C shows an example of the cathode feedthrough conductor shown in FIGS. 8A and 8B. FIG. [Figure 9D] 8C shows an example of the cathode feedthrough conductor shown in FIGS. 8A and 8B. FIG.

[0021] [Figure 9E] 9C and 9D are diagrams illustrating an exemplary formation of a cathode feedthrough assembly with the cathode feedthrough conductors of FIGS. 9C and 9D being joined to the cathode bridge weld in FIGS. 9A and 9B. [Figure 9F] 9C and 9D are diagrams illustrating an exemplary formation of a cathode feedthrough assembly with the cathode feedthrough conductors of FIGS. 9C and 9D being joined to the cathode bridge weld in FIGS. 9A and 9B.

[0022] [Figure 10A] FIG. 8C illustrates one example of the cathode end cap shown in FIGS. 8A and 8B. [Figure 10B] FIG. 8C illustrates one example of the cathode end cap shown in FIGS. 8A and 8B. [Figure 10C] FIG. 8C illustrates one example of the cathode end cap shown in FIGS. 8A and 8B.

[0023] [Figure 11A] FIG. 8C shows an example of the filling tube shown in FIGS. 8A and 8B. [Figure 11B] FIG. 8C shows an example of the filling tube shown in FIGS. 8A and 8B.

[0024] [Figure 12A] 8C shows one example of a feedthrough that can be used with the cathode end cap shown in FIGS. 8A and 8B. FIG. [Figure 12B] 8C shows one example of a feedthrough that can be used with the cathode end cap shown in FIGS. 8A and 8B. FIG. [Figure 12C] 8C shows one example of a feedthrough that can be used with the cathode end cap shown in FIGS. 8A and 8B. FIG. [Figure 12D] 8C shows one example of a feedthrough that can be used with the cathode end cap shown in FIGS. 8A and 8B. FIG.

[0025] [Figure 13A] FIG. 1 illustrates an example of a pressure vessel sidewall according to some embodiments of the present disclosure. [Figure 13B] FIG. 1 illustrates an example of a pressure vessel sidewall according to some embodiments of the present disclosure. [Figure 13C] FIG. 1 illustrates an example of a pressure vessel sidewall according to some embodiments of the present disclosure.

[0026] [Figure 14A] 1A-1C illustrate an example of the assembly of a cathode can assembly according to some embodiments of the present disclosure. [Figure 14B] 1A-1C illustrate an example of the assembly of a cathode can assembly according to some embodiments of the present disclosure.

[0027] [Figure 15A] FIG. 2 illustrates an example of an anode end cap according to some embodiments of the present disclosure. [Figure 15B] FIG. 2 illustrates an example of an anode end cap according to some embodiments of the present disclosure. [Figure 15C] FIG. 2 illustrates an example of an anode end cap according to some embodiments of the present disclosure.

[0028] [Figure 16] 1A-1C illustrate exemplary formations for connecting an electrode stack to an anode end cap, according to some aspects of the present disclosure.

[0029] [Figure 17A] FIG. 1 illustrates an example of an isolator according to some embodiments of the present disclosure. [Figure 17B] FIG. 1 illustrates an example of an isolator according to some embodiments of the present disclosure.

[0030] [Figure 18A] 1A and 1B illustrate an example of a spacer according to some embodiments of the present disclosure. [Figure 18B] 1A and 1B illustrate an example of a spacer according to some embodiments of the present disclosure.

[0031] [Figure 19A] FIG. 1 illustrates an exemplary method for constructing a battery according to some aspects of the disclosure. [Figure 19B] FIG. 1 illustrates an exemplary method for constructing a battery according to some aspects of the disclosure. [Figure 19C]FIG. 1 illustrates an exemplary method for constructing a battery according to some aspects of the disclosure. [Figure 19D] FIG. 1 illustrates an exemplary method for constructing a battery according to some aspects of the disclosure. [Figure 19E] FIG. 1 illustrates an exemplary method for constructing a battery according to some aspects of the disclosure. [Figure 19F] FIG. 1 illustrates an exemplary method for constructing a battery according to some aspects of the disclosure. [Figure 19G] FIG. 1 illustrates an exemplary method for constructing a battery according to some aspects of the disclosure. [Figure 19H] FIG. 1 illustrates an exemplary method for constructing a battery according to some aspects of the disclosure. [Figure 19I] FIG. 1 illustrates an exemplary method for constructing a battery according to some aspects of the disclosure. [Figure 19J] FIG. 1 illustrates an exemplary method for constructing a battery according to some aspects of the disclosure.

[0032] These figures are discussed further below. DETAILED DESCRIPTION OF THE INVENTION

[0033] In the following description, specific details are set forth to illustrate certain aspects of the present invention. However, it will be apparent to those skilled in the art that certain embodiments can be practiced without some or all of these specific details. The specific embodiments disclosed herein are intended to be illustrative and not limiting. Those skilled in the art may recognize other elements not specifically described herein that are within the scope and spirit of the present disclosure. Such modifications may include the substitution of known equivalents for any aspect of the present disclosure to achieve the same result in substantially the same way.

[0034] Consequently, this description illustrates aspects and embodiments of the invention that should not be understood as limiting, and the claims define the protected invention. Various modifications may be made without departing from the spirit and scope of this description and the claims. In some instances, well-known structures and techniques have not been shown or described in detail so as not to obscure the invention.

[0035] Unless the context otherwise requires, throughout this specification and claims, the term "comprises," and variations thereof, such as "comprises" and "comprising," should be construed in an open, inclusive sense, i.e., "including, but not limited to." Throughout this specification, the recitation of numerical ranges of values ​​is intended to serve as a shorthand for individually referring to each separate value within that range, inclusive of the values ​​defining the range, and each separate value is incorporated herein as if it were individually set forth herein. Furthermore, individual values ​​provided for particular components are for illustrative purposes only and should not be considered limiting. Specific dimensional values ​​for various components provide specific examples only, and one of ordinary skill in the art will recognize that embodiments of the present disclosure may be provided with any dimensions. Additionally, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0036] Throughout this specification, a reference to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of the present disclosure. Thus, the appearances of the phrase "in one embodiment" or "in an embodiment" in various places throughout this specification do not necessarily all refer to the same embodiment, but in some cases may. Furthermore, particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0037] In the figures, relative sizes of components are not meaningful and should not be considered limiting unless otherwise noted. Components are sized in the figures to better illustrate various features and structures, without regard to the size they appear to have relative to other components. Furthermore, although specific dimensions are used to describe one example of a battery, those specific dimensions are provided as an example only and are not limiting. Batteries according to the embodiments of the disclosure below can be formed with any dimensions using components with any relative dimensions.

[0038] Metal-hydrogen batteries can be constructed in several ways. In each case, the battery itself includes an electrode stack having a series of electrodes (alternating cathodes and anodes) separated by electrically insulating separators. The electrode stack is housed in a pressure vessel containing an electrolyte and hydrogen gas. The electrode stack can provide an array of cells (i.e., pairs of cathode and anode electrodes) that may be electrically connected in series or in parallel. Electrode stacks according to embodiments of the present disclosure are arranged so that the cells formed in the electrode array are connected in parallel. The stacks can be placed in individual pressure vessels (IPVs), where each electrode stack is housed in a separate IPV.

[0039] 1 shows a schematic diagram of an IPV metal-hydrogen battery 100 according to some embodiments of the present disclosure. The metal-hydrogen battery 100 includes an electrode stack assembly 104 including stacked electrodes separated by a separator 110. The electrodes include a cathode 112, an anode 114, and a separator 110 disposed between the cathode 112 and the anode 114. The separator 110 is saturated with an electrolyte 126. In some embodiments, the separator 110, in addition to being an electrical separator between the cathode 112 and the anode 114, also provides a reservoir of electrolyte 126 that mitigates both drying out and overflowing of the electrolyte during operation.

[0040] Each pair of cathode 112 and anode 114 may be considered a cell, although additional unpaired electrode layers may be present. The electrode stack 104 may be contained within a pressure vessel 102. An electrolyte 126 may be disposed within the pressure vessel 102. The cathode 112, anode 114, and separator 110 are porous to retain the electrolyte 126 and allow ions within the electrolyte 126 to be transported between the cathode 112 and the anode 114. In some embodiments, the separator 110 may be omitted so long as the cathode 112 and the anode 114 can be electrically insulated from each other. For example, the space occupied by the separator 110 may be filled with the electrolyte 126. The metal-hydrogen battery 100 may further include a fill tube 122 configured to introduce electrolyte or gas (e.g., hydrogen) into the pressure vessel 102. The fill tube 122 may include one or more valves (not shown) to control flow into and out of the enclosure 102, or the inlet 122 may be otherwise sealable after filling the pressure vessel 102 with the electrolyte 126 and hydrogen.

[0041] As shown in Figure 1, the electrode stack 104 comprises multiple stacked layers of alternating cathodes 112 and anodes 114 separated by separators 110. A cell may be formed by a pair of cathode 112 and anode 114 layers. While the cells within the electrode stack 104 may be connected either in parallel or in series, in the example battery 100 shown in Figure 1, the cells are connected in parallel. In particular, each of the cathodes 112 is connected to a conductor 118, and each of the anodes 114 is connected to a conductor 116.

[0042] 1 , conductor 116 coupled to anode 114 is electrically coupled to terminal 120, which may represent the negative terminal of battery 100. Terminal 120 may include a feedthrough, allowing terminal 120 to extend outside of pressure vessel 102, or conductor 116 may be connected directly to pressure vessel 102. Similarly, conductor 118 coupled to cathode 112 may be coupled to terminal 124, which corresponds to the positive side of battery 100. Terminal 124 may also include a feedthrough, allowing terminal 124 to extend outside of pressure vessel 102.

[0043] As discussed above, each cell contained within the electrode stack 104 includes a cathode 112 and an anode 114 separated by a separator 110. The electrode stack 104 is positioned within a pressure vessel 102, which holds an electrolyte 126, allowing ions within the electrolyte 126 to be transported between the cathode 112 and the anode 114. As discussed further below, the cathode 112 is formed from a porous conductive substrate coated with a porous compound. Similarly, the anode 114 is formed from a porous conductive substrate coated with a porous catalyst. The separator 110 is a porous insulator that can separate the alternating layers of the cathode 112 and anode 114, retaining the electrolyte 126 and allowing ions within the electrolyte 126 to be transported between the cathode 112 and the anode 114. In some embodiments, the electrolyte 126 is an alkaline aqueous electrolyte (having a pH greater than 7). Each of the anode 114 and the cathode 112 may be formed as an electrode assembly having a multi-layered structure, as discussed further below.

[0044] The electrode stack 104, which is the core of the battery 100, operates chemically to charge and discharge the battery 100 through the hydrogen evolution reaction (HER) and hydrogen oxidation reaction (HOR). These reactions are mechanistically more complex in alkaline conditions than in acidic conditions. Active alkaline HER / HOR catalysts tend to have more dynamic surfaces. In acidic conditions, the reaction proceeds as follows: H + to H2, or H2 to H +The activity of a catalyst for these reactions in acidic conditions can be closely related to the binding energy of hydrogen to the metal surface. If the hydrogen bond is too strong or too weak, the catalytic process cannot proceed effectively and the kinetic overpotential will be large. Platinum has an ideal binding energy for hydrogen and demonstrates better HER / HOR performance in low pH solutions than any other catalyst. In alkaline conditions, free H + The concentration of H is essentially zero, and therefore HER proceeds first via cleavage of the H-O bond of water molecules to produce surface-adsorbed hydrogen atoms and hydroxide anions according to Equation 1 below. This step is slow on metal surfaces, resulting in alkaline HER exchange current densities that are two to three orders of magnitude smaller than on the same metal in acid. Hydrogen gas is produced according to Equation 2 or Equation 3 below. This step (Equation 1) occurs in reverse as the final step of HOR and is the rate-limiting step because the metal surface does not strongly interact with the hydroxide anions required to complete the reaction and form HO. H2O+M+e- <-> MH ad +OH - formula 1 MH ad +H2O+e- <-> M+H2+OH - formula 2 MH ad +MH ad <-> 2M+H2 formula 3

[0045] To accelerate both HER and HOR on a catalyst, a catalytic material is provided that contains (i) metal sites that bind hydrogen and (ii) metal oxide / metal hydroxide sites that bind hydroxide anions. The interface where the metal and metal oxide meet is highly active for both HER and HOR, and an optimal metal-to-metal oxide ratio is maintained to achieve high catalytic activity. If the catalyst surface becomes too oxidized during prolonged or high overpotential HOR, the catalyst surface can become inactive, resulting in impaired battery performance.

[0046] Thus, the anode 114 is a catalytic hydrogen electrode. As discussed above, in some embodiments, the anode 114 includes a porous conductive substrate with a catalytic layer covering the porous conductive substrate. The catalytic layer of the anode 114 may cover the outer surface of the porous conductive substrate of the anode 114, or, since the porous conductive substrate has internal pores or interconnected channels, may also cover the surfaces of those pores and channels. The catalytic layer includes a bifunctional catalyst that catalyzes both HER and HOR in the anode 114. In some embodiments, the porous conductive substrate of the anode 114 may have a porosity of at least about 10%, at least about 20%, at least about 30%, at least about 40%, or at least about 50%, and up to about 80%, up to about 90%, up to about 95%, or more. In some embodiments, the porous conductive substrate of the anode 114 may be a metal foam, such as nickel foam, copper foam, iron foam, steel foam, aluminum foam, or others. In some embodiments, the porous conductive substrate of the anode 114 can be a metal alloy foam, such as nickel-molybdenum foam, nickel-copper foam, nickel-cobalt foam, nickel-tungsten foam, nickel-silver foam, nickel-molybdenum-cobalt foam, or others. Other conductive substrates, such as metal foils, metal meshes, and fibrous conductive substrates, can be used. In some embodiments, the conductive substrate of the anode 114 can be a carbon-based material, such as carbon fiber paper, carbon cloth, carbon felt, carbon mat, carbon nanotube film, graphite foil, graphite foam, graphite mat, graphene foil, graphene fiber, graphene film, and graphene foam.

[0047] In some embodiments, the bifunctional catalyst of the catalytic layer of anode 114 may be a nickel-molybdenum-cobalt (NiMoCo) alloy. Other transition metals or metal alloys as bifunctional catalysts are contemplated by the present disclosure, such as nickel, nickel-molybdenum, nickel-tungsten, nickel-tungsten-cobalt, nickel-carbon, nickel-chromium, and based composites. In some embodiments, the bifunctional catalyst is a transition metal alloy containing two or more of Ni, Co, Cr, Mo, Fe, Mn, and W. Other precious metals and their alloys, such as platinum, palladium, iridium, gold, rhodium, ruthenium, rhenium, osmium, silver, and their alloys with precious and non-precious transition metals, such as platinum, palladium, iridium, gold, rhodium, ruthenium, rhenium, osmium, silver, nickel, cobalt, manganese, iron, molybdenum, tungsten, chromium, and the like, are contemplated by the present disclosure as bifunctional catalysts. In some embodiments, the bifunctional catalyst is a combination of an HER catalyst and an HOR catalyst. In some aspects, the bifunctional catalyst of metal-hydrogen battery 100 comprises a mixture of various materials, such as transition metals and their oxides / hydroxides, which contribute to the overall hydrogen evolution and reduction reactions. In some embodiments, the catalyst layer of anode 114 comprises bifunctional catalyst nanostructures having a size (or average size) in a range, for example, from about 1 nm to about 100 nm, from about 1 nm to about 80 nm, or from about 1 nm to about 50 nm. In some embodiments, catalyst layer 104b comprises bifunctional catalyst microstructures having a size (or average size) in a range, for example, from about 100 nm to about 500 nm, from about 500 nm to about 1000 nm.

[0048] In some embodiments, the catalyst layer on the anode 114 may be partially coated with a surface affinity-modifying material to create different affinities for the electrolyte (e.g., electrolyte 126). For example, if the catalyst layer on the porous substrate of the anode 114 is hydrophilic with respect to the electrolyte, the catalyst layer on the anode 114 may be partially or entirely coated with a material that is hydrophobic with respect to the electrolyte. Conversely, if the catalyst layer on the porous substrate of the anode 114 is hydrophobic with respect to the electrolyte, the catalyst layer on the anode 114 may be partially or entirely coated with a material that is hydrophilic with respect to the electrolyte. This structure may facilitate hydrogen gas migration in the pores of the anode 114 and improve HOR during discharge.

[0049] The cathode 112 can include a conductive substrate and a coating covering the conductive substrate. The coating can include a redox-reactive material including a transition metal. In some embodiments, the conductive substrate of the cathode 112 can be porous, e.g., have a porosity of at least about 10%, at least about 20%, at least about 30%, at least about 40%, or at least about 50%, and up to about 80%, up to about 90%, or more. In some embodiments, the conductive substrate of the cathode 112 can be a metal foam, e.g., nickel foam or a metal alloy foam. Other conductive substrates, such as metal foils, metal meshes, and fibrous conductive substrates, are contemplated by the present disclosure. In some embodiments, the transition metal included in the redox-reactive material is nickel. In some embodiments, the nickel is included as nickel hydroxide or nickel oxyhydroxide. In some embodiments, the transition metal included in the redox-reactive material is cobalt. In some embodiments, the cobalt is included as cobalt oxide or zinc cobalt oxide. In some embodiments, the transition metal included in the redox-reactive material is manganese. In some embodiments, manganese is included as manganese oxide or doped manganese oxide (e.g., doped with nickel, copper, bismuth, yttrium, cobalt, or other transition or post-transition metals). Other transition metals, such as silver, are contemplated by the present disclosure. In some embodiments, cathode 112 is a cathode and anode 114 is an anode. In some embodiments, the coating microstructure of the redox-reactive material can have a size (or average size) within a range, for example, from about 1 μm to about 100 μm, from about 1 μm to about 50 μm, or from about 1 μm to about 10 μm.

[0050] In some embodiments, electrolyte 126 is an aqueous electrolyte. Aqueous electrolytes are alkaline and have a pH greater than 7, e.g., about 7.5 or greater, about 8 or greater, about 8.5 or greater, or about 9 or greater, or about 11 or greater, or about 13 or greater. As non-limiting examples, electrolyte 126 can include KOH or NaOH or LiOH, or a mixture of LiOH, NaOH, and / or KOH.

[0051] Although hydrogen reduction catalysts such as inexpensive transition metals are suitable for metal-hydrogen batteries, they can be passivated during prolonged HOR, which can significantly hinder their use in practical devices. According to some embodiments of the present disclosure, the catalyst of the anode 114 can be a bifunctional transition metal alloy (TMA). In some embodiments, a combination of Ni, Co, Cr, Mo, Fe, and W can be used as a substitute for a bifunctional TMA catalyst. For example, a catalyst composed of Ni with CrO particles attached to its surface can be used. A small amount of Pt can be added to further improve activity. One such TMA catalyst is described in U.S. Patent Application No. 16 / 373,247, the entire contents of which are incorporated herein by reference.

[0052] Additionally, each of the cathode 112 and the anode 114 can include multiple layers of the materials described above. One example of a multi-layer structure anode 114 is provided in U.S. Provisional Application No. 63 / 214,514, which is incorporated herein by reference in its entirety.

[0053] 2A, 2B, 2C, and 2D further illustrate an electrode stack 104 according to some embodiments. According to some aspects of the present disclosure, the cathode 112, anode 114, and separator 110 are each substantially planar with approximately the same planar surface area. The cathode 112, anode 114, and separator 110 can each be produced in a sheet of material of a suitable material as discussed above, and appropriately cut to form the electrode stack 104 discussed here and further below. FIGS. 2A and 2B illustrate a top view and a side view, respectively, of the electrode stack 104. In this reference, "top" refers to a perspective facing the planes of the cathode 112, anode 114, and separator 110, and "side" refers to a perspective into (i.e., along) the planes of the cathode 112, anode 114, and separator 110 that is perpendicular to the top view. FIG. 2C is a cathode end view where each of the cathodes 112 is connected, and FIG. 2D is an anode end view where each of the anodes 114 is connected.

[0054] As shown in the top view shown in FIG. 2A , the electrode stack 104 can be contained within a frame 204. The frame 204 can be a metallic structure that allows penetration of the electrolyte 126 into the layered electrode stack 104. As visible from this embodiment of the frame 204 shown, the separator 110 can be a top layer that electrically insulates whichever is the first electrode below the top separator 110 in the stack. In some embodiments, the anode 114 can form the top and bottom layers of the electrode stack 104, in which case the top / bottom separators 110 (i.e., the separator 110 between the electrode stack 104 and the frame 204) are omitted. In some embodiments, the frame 204 can include a solid plate that covers the separators 110 in the stack, without the large openings shown in FIG. 2A . As further shown in FIG. 2A , according to some aspects of the present disclosure, each of the separators 110 shown in FIG. 1 can include one or more wicking tabs 202. The wicking tab 202 may extend to contact the inner surface of the pressure vessel 102 when the electrode stack 104 is disposed within the pressure vessel 102. The length of the wicking tab 202 may be sufficient to allow the electrolyte 126 to be wicked from the inner surface of the pressure vessel 102 into the electrode stack 104, thereby allowing circulation of the electrolyte 126. Note that the "bottom" view of the electrode stack 104 looks identical to the top view shown in FIG. 2A.

[0055] 2B shows a side view of an electrode stack 104 according to some embodiments of the present disclosure. 2B shows layers of anode 114 and cathode 112 separated by separators 110. As shown, each of the separators 110 includes at least one wicking tab 202. In this example, three wicking tabs 202 are shown for each separator 110 and for each side of the stack 104, although any number of wicking tabs 202 may be included.

[0056] As further shown in Figure 2B, frame 204 includes top and bottom portions 220 and 222 connected by side supports 206. As shown in Figure 2A, top and bottom portions 220 and 222 cover separators 202 on the top and bottom of electrode stack 104, respectively. As further shown, each of the cathodes 112 is electrically connected to a conductor 118, while each of the anodes 114 is electrically connected to a conductor 116.

[0057] As further shown in FIG. 2B , the top portion 220 and the bottom portion 222 are structurally connected using side supports 206. There can be any number of side supports 206 on each side. The side supports 206 can be welded, for example, to secure the top portion 220 and the bottom portion 222, and thus secure the stacked electrodes of the electrode stack 104 within the fixed frame 204. As discussed in more detail below, a stack of electrodes can be formed between the bottom portion 222 and the top portion 220, pressure can be applied to the stack, and the side supports 206 can be welded to the top portion 220 and the bottom portion 222 while pressure is applied to form the frame 204. As discussed further below, in some embodiments, the top portion 220 and the bottom portion 222 can be formed separately, and side supports are used to secure the top portion 220 to the bottom portion 222.

[0058] 2C shows an end view facing the conductor 118 according to some embodiments. As shown in FIG. 2C, the end conductor 118 may be formed by stacking cathode bus bars 212, each of which is electrically coupled to the cathode 112. The cathode bus bars 212 may be electrically and mechanically attached (e.g., by welding) to form the conductor 118.

[0059] 2D shows anode bus bars 214 stacked to form conductor 116. Anode bus bars 214 are electrically connected to anode 114 and are electrically and mechanically attached, for example by welding, to form anode conductor 116.

[0060] 3A, 3B, and 3C illustrate the formation of separator 110 according to some embodiments. FIGS. 3A and 3B show separator layers 300, which may be stacked to form separator 110, as shown in FIG. 3C. As discussed above, separator layers 300 may be stacked to form separator 110, as shown in FIG. 3B, with a thickness of t s The separator layer 300 may be formed from a sheet of separator material, such as a porous plastic. FIG. 3A shows a plan view facing the surface of the separator layer 300. As shown in FIG. 3A, the wicking tabs 202 shown in FIG. 2A are represented in FIG. 3A by wicking tabs 304, 306, 308, 310, 312, and 314. The wicking tabs 304, 306, 308, 310, 312, and 314 are symmetrically positioned about the centerline 302 and may also be symmetrical on both sides (as shown in FIG. 3A). However, in some embodiments, the wicking tabs 304, 306, 308, 310, 312, and 314 may have different sizes and arrangements on opposite sides of the separator 110. The wicking tabs 304, 306, 308, 310, 312, and 314 are spaced apart from one another within the width w of the separator layer 300. s 2, while the main body of separator layer 300 has a width w s 1, (w s 2-w s 1) provides the length of each of the wicking tabs 304, 306, 308, 310, 312, and 314. The total length of the separator 110 is L s Furthermore, from the center line 302, the wicking tab 306 is -L s 1 to +L s 1, and the wicking tab 308 extends to L s 2 to L s 3, and the wicking tab 304 is -L s 2 to -Ls 3, and the wicking tab 312 is -L s 1 to +L s 1, and the wicking tab 314 extends to L s 4 to L s 5, and the wicking tab 310 is -L s 4 to -L s 5. As shown in FIG. 3B, separator layer 300 has a thickness t s Specific examples of separator layer 300 may be provided with the following dimensions: L s =241mm;L s 1=16.0mm;L s 2=53.0mm;L s 3=81.0mm;L s 4=49.0mm;L s 5=77.0mm;w s 1=75.0mm;w s 2=111.0 mm; and t s = 0.25 mm. However, separator layer 300 may have any set of dimensions, and in particular, separator layer 300 may be symmetrical on both sides. Additionally, in some embodiments, separator layer 300 may be formed from a fully porous plastic.

[0061] 3A , each of wicking tabs 304, 306, 308, 310, 312, and 314 includes alignment holes 316, 318, 320, 322, 324, and 326, respectively. Alignment holes 316, 318, 320, 322, 324, and 326 may be used during assembly of electrode stack 104, as discussed further below. Alignment holes 316, 318, 320, 322, 324, and 326 may be positioned anywhere on wicking tabs 304, 306, 308, 310, 312, and 314, respectively.

[0062] 3C illustrates the formation of separator 110 from one or more separator layers 300. As shown, separator 110 can include any number of stacked separator layers 300. In some embodiments, for example, two separator layers 300 are used to form separator 110.

[0063] 4A through 4F illustrate an anode assembly 400 including an anode 114 and a bus bar 214, as shown in FIG. 4A. FIGS. 4A and 4B illustrate an example of the anode assembly 400, FIGS. 4C and 4D illustrate an example of the anode 114, and FIGS. 4E and 4F illustrate an example of the bus bar 214. According to some embodiments of the present disclosure, the anode assembly 400 includes the anode 114 electrically and mechanically coupled to the anode bus bar 214, as shown in the top view shown in FIG. 4A. FIG. 4A also illustrates that the anode bus bar 214 can include alignment features 410, 412, and 414 that can be used to align the anode assembly 400 within the stack 104, among other features. As shown in the side view shown in FIG. 4B, the anode 114 can include multiple layers of anode material. As shown in FIG. 4B , in some embodiments, the anode 114 can include three layers. In some embodiments, a layer 420 can separate two layers 402. As discussed above, in some embodiments, layers 402 and 420 can be formed using an anode material (e.g., a nickel foam substrate) with layer 420 being corrugated while layer 402 is not. This arrangement of the anode layers aids in hydrogen gas transport into and out of the center of the stack 104. Other arrangements of the anode 114 can be formed. A bus bar 214 is attached to the anode 114 to aid in stacking and form the anode conductor 116 when the stack 104 is assembled.

[0064] 4C and 4D show an anode 114 according to some embodiments of the present disclosure. In this example, the anode 114 includes three layers, two layers 402 and layer 420, as discussed above with respect to FIG. 4B. As shown in FIGS. 4C and 4D, the anode 114 can be formed using one or more sheets of anode material as discussed above. Each of the layers 402 and 420 can be cut from a sheet of anode material. The anode 114 has an overall length L A and width w A The thickness TA1 of the anode 114 is the thickness of the three layers of material: the two anode material layers 402 and the center layer 420. A tab portion 404 of length LA1 is formed on one end of the anode 114. The tab portion 404 is formed by pressing the three anode material layers together to bond the three layers and flatten the area. FIG. 4C shows layers 402 and 420 pressed together to form the tab portion 404. The tab portion 404 extends from one end of layer 402 to a length L A Thickness T over 1 A 2. The anode bus bar 214 may be spot welded onto the tab area 404. As further shown in FIG. 4D , in some embodiments, the alignment notches 406 and 408 extend over the length L of the tab portion 404. A The alignment notch 406 is formed in the L A The alignment portions 406 and 408 are positioned at position 2, while the alignment notch 408 is positioned at the center of a length wA2 from either side. The alignment portions 406 and 408 are formed by a circle with a radius RA1. The center of the alignment portion 408 is separated from the center of the alignment hole 406 by a length LA3.

[0065] 4E and 4F show a bus bar 214 electrically and mechanically connected to the anode 114 as shown in FIGS. 4A and 4B. As noted above, the bus bar 214 is spot welded onto the tab area 404 of the anode 114. FIG. 4E shows a top view of the bus bar 214, and FIG. 4F shows a side view of the bus bar 214. The anode bus bar 214 may be formed from any metallic conductor, for example, nickel, and has a width W A 2. Length L A 5, and thickness t A 3. As further shown in FIG. 4E, bus 214 includes alignment portions 410, 412, and 414, each of which has a radius R A The alignment portions 410 and 412 are formed by holes of length L from the side including the alignment portion 414. A The alignment portion 414 is located at position 6. The alignment portion 414 has a length L A 7. When the bus bar 214 is attached to the tab region 404 of the anode 114, the alignment portions 410 and 412 can be aligned with the alignment notches 406 and 408 of the tab portion 404.

[0066] The relative dimensions shown in Figures 4A, 4B, 4C, and 4D may vary according to the specific system. A specific example, consistent with the specific example of separator 110 described above with respect to Figures 3A and 3B, may be as follows: A =250mm;L A 1=10.2mm;L A 2=5mm;L A 3=1mm;L A 5=10.000mm;L A 6=5.000mm;L A 7=1.000mm;w A 1=70mm;w A 2=34.000mm;w A 3=70.000mm;w A 4=34.000mm;t A 2=0.45mm;t A 3=3.175mm;R A1=2.1000mm; and R A 2=3.100 mm. In some embodiments, the anode assembly 400 may be coated, for example with a Teflon coating. The anode assembly 400 may then be oven dried and sintered to finalize the production of the anode assembly 400.

[0067] 5A through 5I illustrate the formation of a cathode assembly 500 according to some embodiments of the present disclosure. As shown in FIG. 5A, the cathode assembly 500 includes a cathode 112 attached to a cathode bus bar 212. As shown in FIG. 5B and discussed above, the cathode 112 can include multiple layers 502 of cathode material. The bus bar 212 can include an alignment notch 510 and alignment portions 506 and 508, as shown in FIG. 5A. The alignment notch 510 can assist in electrically connecting the cathode conductors 118 formed by stacking the layers of the cathode assembly 500, as will be further discussed. The alignment portions 510, 506, and 508 can be used during the formation of the electrode stack 104. It should be appreciated that the alignment portions 506, 508, and 510 can be any shape, and the specific shapes discussed herein are examples and should not be considered limiting.

[0068] 5C and 5D show one example of a layer 502 of the exemplary cathode 112 shown in FIGS. 5A and 5B. The layer 502 may be formed from a larger sheet of cathode material and a tab 514 attached to the cathode material 516. The exemplary layer 502 shown in FIGS. 5C and 5D has a length L c and width w c The cathode material 516 of the layer 502 has a thickness t cAs shown in FIG. 5C , layer 502 includes a tab 514 attached to one end of cathode material layer 516. In some embodiments, the cathode material sheet may be purchased with tab 514 already attached, and cathode layer 502 is formed by cutting the cathode material sheet. Tab 514 may be made from any metal, such as nickel-plated SPCC steel (a grade of cold-rolled steel), and may be resistance seam welded onto the cathode material. As discussed further below, cathode busbar 214 may be welded to tabs 514 of two cathode layers 502 to complete cathode assembly 500 shown in FIGS. 5A and 5B . As shown in FIG. 5D , tab 514 may be cut to form alignment notch 522 and two alignment portions 520 and 524. As shown, the alignment feature 520 may be formed by a hole of radius Rc1 centered a width wc2 from the centerline 528 and a length Lc2 from the end of the tab 514 of the cathode layer 502. The alignment notch 522 may be formed by two holes of radius Rc1 formed a width wc1 from the centerline 528 and a depth Lc1 from the end. A weld point a length Lc3 from the end indicates where the tab 514 is welded to the cathode material layer 502.

[0069] 5E and 5F show one example of a cathode bus bar 212. As discussed above, the cathode bus bar 212 is electrically and mechanically connected to the cathode material 516 at the cathode tabs 514, which are shown in FIGS. 5A and 5B. The cathode bus bar 212 may be formed from any metallic conductor, for example, nickel, and may have a width w c 1, length Lc6+Lc7, and thickness t c 5E, the cathode bus bar 212 includes alignment portions 506, 508, and 510. The alignment portions 506 and 508 are spaced apart from the edge by a length L c Positioned at position 5, from the width center line 530 to the width w cRadius R separated by 2 c The alignment portion 510 is formed by holes on opposite edges of the cathode bus 212, each having a central width w c 4 slot. Furthermore, the alignment portion 510 is such that the overall width of the slot is w c 5E, alignment slot 510 includes two holes on either side of centerline 530 spaced a width wc3 apart from centerline 532 along busbar 212, each hole having a radius Rc3 and a center at a length Lc4 from centerline 532. The depth of the slot in alignment portion 510 is a length Lc4. c 5. Alignment portions 506, 508, and 510 are aligned with alignment portions 520, 524, and 522 of cathode layer 502. Alignment portions 506, 508, and 510 of cathode bus bar 212 are distinct from alignment portions 410, 412, and 414 of anode bus bar 214, which aids in distinguishing the two during assembly of electrode stack 104 so that there is no error in positioning anode assembly 400 relative to cathode assembly 500. Additionally, alignment notches 510 allow for connection of the cathode assembly to cathode conductors 118 formed by stacked cathode bus bars 212, as discussed further below.

[0070] Once the cathode layers 502 are cut and shaped with the tabs 514 attached to the cathode material 516, the bus bar 212 is spot welded onto the tabs 514 of the two cathode layers 502 to form a single two-layer cathode assembly 500. The nickel bus bar 212 aids in stacking and forms the cathode bus 218, which is discussed further below.

[0071] Although the dimensions of the cathode assembly 500 may be any dimensions, specific examples of the dimensions shown in Figures 5C to 5F that are consistent with the specific examples shown in Figures 3A and 3B, and Figures 4A to 4D, may be as follows: Lc = 251.0 mm; Lc1 = 1.0 mm; Lc2 = 5.0 mm; Lc3 = 11.0 mm; Lc4 = 4.0 mm; Lc5 = 1.8 mm; Lc6 = 5.0 mm; Lc7 = 5.0 mm; wc = 70.0 mm; wc1 = 15.0 mm; wc2 = 34.0 mm; wc3 = 15.0 mm; wc4 = 36.2 mm; wc5 = 70.0 mm; tc = 0.5 mm; tc1 = 0.1 mm; tc2 = 3.2 mm; Rc1 = 3.1 mm; Rc2 = 3.1 mm; and Rc3 = 3.1 mm. It should be noted that the dimensions for a specific compatible example of the separator 110, anode assembly 400, and cathode assembly 500 are provided for illustrative purposes only. This specific example should not be considered limiting, but rather is one specific example of an embodiment of the present disclosure. One skilled in the art may provide any set of compatible dimensions for constructing an electrode stack 104 according to the present disclosure.

[0072] Additionally, Figure 6A illustrates the separator 110, cathode assembly 500, and anode assembly 400, as described above with respect to one another. Figure 6B illustrates the assembly of the electrode stack 104 by configuring and stacking the electrodes and separators using an alignment jig 602. As shown in Figure 6B, the alignment jig 602 is positioned on a base 618 and includes a plurality of alignment bars corresponding to the alignment features discussed above with respect to the separator 110, anode assembly 400, and cathode assembly 500. In particular, alignment bars 604, 606, and 608 are aligned with alignment features 410, 414, and 412 of the anode assembly 400, respectively. Alignment bars 612, 614, and 616 are aligned with alignment features 506, 508, and 510 of the cathode assembly 500. Additionally, each of the alignment rods 610 is positioned to align with one of the alignment holes 316, 318, 320, 322, 324, and 326 of the separator 110. As shown, when an alignment rod is aligned with a corresponding alignment portion of a corresponding one of the separator 110, cathode assembly 500, or anode assembly 400, that component is properly aligned on the alignment jig 602.

[0073] During operation, an operator can quickly and accurately assemble an electrode stack 104 with the appropriate number of separators 110, cathode assemblies 500, and anode assemblies 400. Beginning with placing the bottom portion 222 of the frame 204, which may already have side supports 206 attached, into the jig 602, the operator then adds electrode assemblies separated by separators 110, alternating anode assemblies 400 and cathode assemblies 500 separated by separators 110, until the stack is the full width of the appropriate number of anode assemblies 400 and cathode assemblies 500. In some embodiments, two separators 110 can be stacked to provide better insulation between other stacked electrodes. In a particular example, an electrode stack can include twenty (21) anode assemblies 400 (each with three anode layers) and twenty (20) cathode assemblies 500 (each with two cathode layers). Providing an anode assembly 400 on either side of the electrode stack prevents the cathode assembly 500 from shorting to the frame 204, and symmetry aids in repeated charge / discharge cycles. Finally, the top portion 220 is added to the stack in a jig 602.

[0074] Once the layers of separator 110, anode assembly 400, and cathode assembly 500 are assembled on alignment jig 602, the alignment jig 602 is then placed into press 630, as shown in FIG. 6C. Press 630 is aligned using alignment rods 620 on base 618 of jig 602, which are inserted into sleeve 634 of press 630. Press 630 includes jaws 632 that press the stack of electrodes and separators within jig 602. While any pressure can be used, in a specific example consistent with the dimensions provided above, a pressure of 0.58 MPa can be applied. While under pressure, side supports 206 can be welded at spots 636. Additionally, the anode buses 214 for each of the anode assemblies 400 are welded together at weld 640 to form the conductor 116, and the cathode buses 212 for each of the cathode assemblies 500 are welded together at weld 638 to form the conductor 118. After the welding process, the assembled electrode stack 104 may be removed from the press 630 and alignment jig 602.

[0075] Figures 7A-7H show one example of top and bottom portions 220, 222 of frame 204, which are overlapped and welded as shown in Figure 6C to form side supports 206 and frame 204. Figures 7A-7D show inner region 702, which may be top portion 220 or bottom portion 222. Figures 7E-7H show outer region 704, which may also be top portion 220 or bottom portion 222 of frame 204. Inner region 702 and outer region 704 may be aligned and attached to form frame 204.

[0076] Inner portion 702 is shown in Figures 7A through 7D. Figure 7A shows a first side view of inner portion 702, Figure 7B shows a top view of inner portion 702, and Figure 7C shows another side view of inner portion 702. As shown in Figure 7A, inner portion 702 shows fingers 706 that are spaced apart along the length of inner portion 702. Tab regions 708 extend from each elongated end of inner portion 702. Tab regions 708 are shown in Figure 7D.

[0077] FIG. 7A shows a side view of inner portion 702. As shown in FIGS. 7A and 7B, inner portion 702 has a length of LFI and an overall width of wFI2. As shown in FIGS. 7A and 7C, fingers 706 are disposed along the long edge of inner portion 702. In the example shown in FIGS. 7A and 7B, four fingers 706 are distributed on either side of centerline 710, such that two inner fingers 706 are each a length LFI2 from centerline 710 (separated by 2*LFI2), while the other two fingers 706 are each a length LFI1 from centerline 710 (separated by 2*LFI1). As shown in FIG. 7B, the overall width of inner portion 702 is wFI2, while the width of plate 712, with which fingers 706 are integrally formed, is wFI1. As shown in FIG. 7C, each of the fingers 706 extends from the plate 712 a length of LFI4 and has a width of wFI3.

[0078] 7A and 7D, tab 708 extends perpendicularly from plate 712 a length LFI3. As shown in FIG. 7D, tab 708 may have a rounded end portion 716 with a mounting hole 718 in rounded end portion 716 extending perpendicularly from plate 712. In the example shown in FIG. 7D, portion 716 is formed with a rounded portion having a radius RFI1 that transitions from a flat portion 714 having a radius RFI2. Hole 718 is elongated and may be formed by two holes of radius RFI3 spaced apart from their centers by a length LFI4, which are spaced apart from the ends of flat portion 714 by a length LFI3.

[0079] The outer portion 704 is shown in Figures 7E through 7H. Figure 7E shows a first side view of the outer portion 704, Figure 7F shows a top view of the outer portion 704, and Figure 7G shows another side view of the outer portion 704. As shown in Figure 7E, the outer portion 704 shows fingers 726 that are spaced apart along the length of the outer portion 704. A tab region 728 extends from each elongated end of the outer portion 704. The tab region 728 is shown in Figure 7H.

[0080] FIG. 7E shows a side view of the outer portion 704. As shown in FIGS. 7E and 7G, the outer portion 704 has a length of LFO and an overall width of wFO2. As shown in FIGS. 7E and 7G, fingers 726 are disposed along the long edge of the outer portion 704. In the example shown in FIGS. 7E and 7F, four fingers 726 are distributed on either side of a centerline 730, such that two inner fingers 726 are each a length LFO2 on either side of the centerline 730 (separated by 2*LFO2), while the other two fingers 726 are each a length LFO1 from the centerline 730 (separated by 2*LFO1). As shown in FIG. 7F, the overall width of the outer portion 704 is wFO2, while the width of the plate 732 to which the fingers 726 are attached is wFO1. As shown in FIG. 7G, each of the fingers 726 extends from the plate 732 a length of LFO4 and has a width of wFO3.

[0081] 7E and 7G, each of the fingers 726 includes a hole 740. In the particular example shown here, the holes 740 may include three holes positioned at LFO7, LFO8, and LFO9 from the end of the fingers 726. When the frame 204 is formed, the fingers 726 of the outer portion 704 may engage and be welded to the fingers 706 of the inner portion 702 via the holes 740.

[0082] As shown in Figures 7E and 7H, tab 728 extends perpendicularly from plate 732 a length LFO3. As shown in Figure 7H, tab 728 includes portion 736 with mounting hole 738 extending perpendicularly from plate 732. In the example shown in Figure 7H, rounded portion 736 is formed with a rounded portion having a radius RF01 that transitions from plate 732 at a radius of RF02. Hole 738 is elongated and may be formed by two holes of radius RF03 separated from the center by a length LFO4, which are separated from the end of plate 732 by a length LFO3.

[0083] In a particular specific example of inner portion 702 and outer portion 704, the dimensions may be given by: LFI=241.2 mm; LFI1=97.5 mm; LFI2=32.5 mm; LFI3=17.0 mm; LFI4=56.0 mm; LFI5=8.0 mm; LFI6=3.0 mm; wFI1=72.0 mm; wFI2=80.0 mm; wFI3= 10.0 mm; RFI1 = 54.0 mm; RFI2 = 2.5 mm; RFI3 = 3.25 mm; LFO = 241.2 mm; LFO1 = 97.5 mm; LFO2 = 32.5 mm; LFO3 = 17.0 mm; LFO4 = 51.0 mm; LFO5 = 11.0 mm; LFO6 = 8.0 mm; LFO7 = 5.0 mm; LFO8 = 15.0 mm; LFO9 = 25.0 mm wFO1 = 70.0 mm; wFO2 = 83.0 mm; wFO3 = 10.0 mm; RFO1 = 54.0 mm; RFO2 = 5.0 mm; and RFO3 = 3.3 mm. In particular, inner portion 702 and outer portion 704 may be formed from a sheet of stainless steel that is cut and bent as described above. In some embodiments, fingers 706 and 726 may be formed separately and welded to plates 712 and 732, respectively, to form inner portion 702 and outer portion 704 as described above. Outer portion 704 fits onto inner portion 702 and is welded thereto to form frame 204.

[0084] 8A through 8G illustrate an embodiment of the assembly of a battery 100 having the components described above. FIG. 8A shows an anode assembly 850 including an electrode stack 104 having an attached cathode feedthrough assembly 802 attached to the cathode conductor 118 of the stack 104 and an attached anode end cap 804 attached to the anode conductor 116 of the stack 104. As shown in FIG. 8A, the feedthrough assembly 802 includes a bridge 810 and a cathode feedthrough conductor 812. The bridge 810 is welded to the cathode conductor 118 at a weld point 842 in a slot formed by the alignment slot 710 in the cathode assembly 500. The anode conductor 116 is welded to the anode end plate 804 at a weld 840. Furthermore, the anode end plate 804 is attached to at least one of the tabs 728 and 708 with a bolt 830 using a spacer 822.

[0085] Additionally, FIG. 8B illustrates an assembled battery 100 according to an embodiment of the present disclosure. As shown in FIG. 8B, a cathode feedthrough assembly 802 includes a cathode bridge 810 connected to a cathode conductor 118 and a feedthrough conductor 812 connected to the cathode bridge 810. As shown, the cathode feedthrough assembly extends through a cathode end plate 808 to which a feedthrough 815 and a fill tube 816 are attached. Additionally, a side wall 826 may be welded to the cathode end plate 808 before mating to the assembly 850. The feedthrough 815 is connected to the end plate 808 and seals against the feedthrough conductor 812. 8A and 8B show the process by which assembly 850 is formed, cathode end cap 808 and side wall 826 are assembled at weld 842, and then assembly 850 is positioned onto side wall 826, which is welded to anode end plate 804 at weld 806.

[0086] FIG. 8C shows a blow-out view of a battery 100 according to some embodiments. As shown in FIG. 8C, the stack 104 illustrates an arrangement of an outer portion 704 and an inner portion 702. As shown, when the stack 104 is assembled, it fits within a sidewall 826, and the anode conductor 116 is connected to an end plate 804, as discussed further below. As further shown, a bolt 830 can be inserted through the tab 728 and spacer 822 and threaded into a mounting hole 832 on the anode end plate 804. A similar arrangement can be formed to connect the tab 728 to the isolator 820. A similar arrangement can be provided with the inner portion 702 having the tab 708.

[0087] 8C , the cathode conductor 118 is connected to a cathode feedthrough conductor 812 that extends through a feedthrough 815. An isolator 820 can be disposed between the cathode conductor 118 and the cathode end plate 808, such that the feedthrough conductor 812 extends through the isolator 820. As further shown, the fill tube 816 allows access to the interior of the pressure vessel 102 through the cathode end cap 808 when the cathode end cap 808 is welded to the side wall 826 and the anode end cap 804 is welded to the opposite side of the side wall 826 to form the pressure vessel 102.

[0088] Additionally, FIG. 8D illustrates a partially assembled assembly 850. As shown in FIG. 8D, the assembled stack 104 is attached to a feedthrough assembly 802, which includes a cathode feedthrough conductor 812 and a cathode bridge 810. FIG. 8D illustrates a perspective facing the plate 732 of the outer portion 704. FIG. 8D illustrates the wicking tab 828, which corresponds to the wicking tabs 304, 306, 308, 310, 312, and 314 illustrated in FIG. 3A. Additionally, FIG. 8D illustrates the anode conductor 118 formed by the stacked anode bus bars 214 and the cathode conductor 116 formed by the stacked cathode bus bars 212. Additionally, FIG. 8D illustrates how the cathode bridge 810 is inserted into the groove formed by the stacked cathode bus bars 212.

[0089] 8E shows a side view of the stack 104 with the cathode feedthrough conductors 812 and cathode bridge 810 attached. As shown in FIG. 8E, the fingers 726 of the outer portion 704 of the frame 204 are positioned above the fingers 706 of the inner portion 702 of the frame 204 and welded to hold the stack 104 rigidly.

[0090] Figures 8F and 8G show views from each end of the stack 104. Figure 8F shows the cathode side, showing the cathode bridge 810 and cathode feedthrough conductors 812 attached to the cathode conductors 116 formed by the stacked cathode bus bars 212. Figure 8G shows the anode conductors 118.

[0091] 9A and 9B show an example of a cathode bridge 810, while FIGS. 9C and 9D show an example of a feed-through conductor 812. As shown in FIGS. 9A and 9B, the cathode bridge 810 has a length L cb , width w cb , and thickness t cb In some embodiments, the conductive plate may be formed of a length L cband width w cb may be positioned such that plate 810 is contained within a recess in cathode conductor 118 formed by alignment slot 510. In a specific example consistent with the specific example provided above, L cb =70.0mm;w cb = 20.0 mm; and t cb = 3.175 mm. Although any conductive material consistent with the material used for the cathode conductor 118 may be used to form the cathode bridge 810, in some embodiments, the cathode bridge 810 may be formed from nickel.

[0092] 9C and 9D show an exemplary feedthrough conductor 812. FIG. 9C shows the length of the feedthrough conductor 812, while FIG. 9D shows an end view of the feedthrough conductor 812. As shown in FIGS. 9C and 9D, the feedthrough conductor 812 has an overall length L cf 2 rods, where the length L cf 1 is diameter D cf and the remainder (L cf 2-L cf 1) is screw specification T cf The feedthrough conductors 812 are threaded so that they meet the requirements. The feedthrough conductors 812 may be formed from any conductive material compatible with the material of the cathode conductors 118, such as nickel. As shown in FIG. 8B , the feedthrough conductors 812 are attached to the cathode bridge 810. In some embodiments, the feedthrough conductors 812 are welded onto the bridge 810 as a subassembly 802, which is then placed over the cathode bus 118 and welded to the bus bar 212 at the alignment notch 510. In one specific example, the feedthrough conductors 812 may have dimensions Lcf1=75.0 mm; Lcf2=85.0 mm; Dcf=10.0 mm; and Tcf is M8x1.0.

[0093] 9E and 9F show an assembled cathode feedthrough assembly 802 according to some embodiments. Fig. 9E shows a top view with the feedthrough conductor 812 positioned and welded onto the cathode bridge 810. Fig. 9F shows a side view of the feedthrough assembly 802 with the feedthrough conductor 812 positioned and welded to the cathode bridge 810 at weld 906.

[0094] 10A, 10B, and 10C show an example of a cathode end plate 808. FIG. 10A shows a top view of the end plate 808. As shown in FIGS. 10A and 10B, the cathode end plate 808 is formed from a circular disk. As shown in FIG. 10A, the end plate 808 has a diameter D formed at the center of the end plate 808. cec 1 through-hole portion 1010, and a distance L from the center of the through-hole portion 1010 cec Diameter D offset by 1 cec 2 and 3. The through-hole 1010 allows for the passage of the feed-through conductor 812 and the feed-through 815, while the through-hole 1012 allows for the fill tube 816.

[0095] 10B shows an edge view along line 1018, which is a line perpendicular to the line connecting the centers of through-holes 1010 and 1012, and shows a mating edge that can be used to attach to sidewall 826. As shown in FIG. 10B, end plate 808 has a cec The end plate 808 has an overall thickness of D cec 10B. The insert 1016 has an inner diameter of t.sub.3, allowing for insertion of the insert 1016 into the sidewall 826. The thickness of the insert 1016 is t.sub.cec2. FIG. 10C shows the region of the edge view shown in FIG. 10B circled by area A. As shown in FIG. 10C, the thickness t.sub.cec2. cec 3 and a flat lip of length Lcec3, which has a length L cec2 tapered portion. Consequently, the overall diameter of end plate 808 may be Dcec3+2*Lcec3+2*Lcec2. End plate 808 may be formed from any metallic conductor, and in some embodiments, end plate 808 may be formed from stainless steel. In a specific example consistent with those specific examples provided above, end plate 808 may have the following dimensions: Dcec3+2*Lcec3+2*Lcec2. cec 1=20.0mm;D cec 2=6.5mm;D cec 3=106.5mm;t cec 1=19.25mm;t cec 2=4.25mm;t cec 3=2.15mm;L cec 1=40.0mm;L cec 2 = 2.15 mm; and L cec 3=1.74 mm. As discussed above, this specific example is given by way of example only and is not intended to be limiting.

[0096] 11A and 11B show an example of a fill tube 816 according to some embodiments. The fill tube 816 can be inserted into the through-hole 1012 of the end plate 808 and welded in place to add electrolyte 126 to the pressure vessel 102. As shown in FIG. 11B, the fill tube 816 has a length L t and outer diameter D t 11A, the wall thickness of the fill tube 816 can be tt. Any tube that can be sealed within the through-hole 1012 can be used. In some examples, a metal compatible with that of the end plate 808 can be used, such as stainless steel. As discussed above, once the pressure vessel 102 has been properly filled with electrolyte 126 and then drained, the fill tube 816 can be sealed, for example, by crimping the fill tube 816. In a specific example compatible with those provided above, the fill tube 816 can have the following dimensions: L t = 90.0 mm; D t = 6.350 mm; and t t=0.89mm.

[0097] 12A, 12B, 12C, and 12D show one embodiment of a feedthrough 815 according to some aspects of the present disclosure. The feedthrough 815 includes a body 1202, shown in FIGS. 12A and 12B, and an insulator 1208, shown in FIGS. 12C and 12D. The feedthrough 815 is assembled by mating the insulator 1208 with the body 1202 such that the feedthrough conductor 812 extends through and can be sealed to the insulator 1208. The body 1202 can be formed from any material, such as a metal, that can be physically attached to and sealed to the cathode end cap 808.

[0098] As shown in FIG. 12A, one example of a cylindrically shaped body 1202 is L ft The body 1202 includes a base portion 1204 and a body portion 1206 that are integral with one another (e.g., formed as a single piece). The base portion 1204 has a length of L ft W over the length of 5 ft Measured from the bottom of the base portion 1204, the diameter of the base portion 1204 may be L ft 3 and L ft The length of the body portion 1206 between the two ft The top and L of the base portion 1204 have an outer diameter of 1.2 mm. ft The body portion 1206 has a length of up to 4 mm. ft It has an outer diameter of 3. Length L ft 2 and L ft Between 1 and L ft 4 and L ft Between the three, the main body part 1206 is w ft 2 and w ft 3 diameter. The body 1202 can be positioned over the through-hole 1010 and welded in place. Additionally, the body 1202 has an interior structure configured to receive an insulator 1208.

[0099] 12B shows a cross-sectional view of the body 1202 from above, looking at the body portion 1206 and the base portion 1204. As shown, the central portion 1214 is ft TS with a thread depth of 1 ft It has an internal thread which may be a standard thread characterized by 1.

[0100] 12C and 12D show the insulator 1208 of the feedthrough 815. The insulator 1208 includes a body portion 1212 and a base portion 1210 and may be formed from an insulating material. As shown in FIG. 12C, the insulator 1208 has a L ft 6, while body portion 1212 has a length of L ft The diameter of the base portion 1210 is w ft 12D shows a cross-sectional view of the insulator 1208. As shown in FIG. ft The inner through-holes 1216 of the D are sized to engage with the feed-through conductors 812. ft is the diameter D cf 12D, the body portion 1212 is such that it allows the conductor 812 of the TS ft 12. In particular, the external threads of body portion 1212 engage with the internal threads of body portion 1206 such that insulator 1208 is threaded into body 1202. In some embodiments, the internal threads of body portion 1206 and the external threads of insulator 1208 may be pipe threads that provide a seal when they engage with one another.

[0101] In a specific example of the feedthrough 815 consistent with the specific example discussed above, the following dimensions and characteristics may be used: ft 1=44.0mm;L ft 2=39.5mm;L ft 3=10.5mm;L ft 4=6.0mm;L ft 5=4.0mm;L ft 6=42.0mm;L ft7=40.0mm;w ft 1=30.0mm;w ft 2=20.0mm;w ft 3=19.2mm;w ft 4=20.0mm;D ft =10.0mm;TS ft 1=G3 / 8-19;TS ft 2=G3 / 8-19; and TD ft 1=0.4 mm. The body 1202 may be metallic and consistent with the material of the cathode end plate 808 (e.g., may be welded or otherwise attached to the cathode end plate 808). In some examples, the body 1202 may be stainless steel. The insulator 1208 may be any insulator, such as ultra-high molecular weight polyethylene (UHMW) plastic.

[0102] 13A, 13B, and 13C show one example of a sidewall 826 of the pressure vessel 102. As shown in FIG. 13A, the sidewall 826 has a length L v 1, outer diameter D v 1, and the inner diameter D v 13B shows the area of ​​lip 1302 of sidewall 826 enclosed within circle A in FIG. 13A that mates with end caps 804 and 808. As shown in FIG. 13B, sidewall 826 has a thickness t v 1 and has a length L v 2 and thickness t v 2( <t v 1). Lip 1302 is therefore positioned to receive end caps 804 and 808 to form pressure vessel 102. FIG. 13C shows a cross-sectional view of one end of sidewall 826 shown in FIG. 13A. In a specific example consistent with other specific examples provided above. L v 1=280.0mm;L v 2=2.15mm;t v 1=3.05mm;t v 2=2.15mm; Dv1=114.3mm; and Dv2=108.2mm.

[0103] 14A and 14B illustrate the assembly of a cathode end cap 808, a fill tube 816, a feedthrough 815, and a sidewall 826 according to some embodiments of the present disclosure. As shown in FIG. 14A , the fill tube 816 is inserted into a through-hole 1012 in the cathode end cap 808 and, in some examples, is welded in place to seal the periphery of the fill tube 816. In some examples shown in FIG. 14A , the fill tube 816 can extend through the cathode end cap 808 by a length Lt1, for example. In a specific example, the length Lt1 can be approximately 1 mm. Additionally, the body 1202 of the feedthrough 815 can be positioned and welded over the through-hole 1010 in the end cap 808 such that the through-hole 1010 is aligned with the inner through-hole 1216 of the insulator 1208.

[0104] In some embodiments, body 1202 can be welded to cathode end plate 808 in alignment with through hole 1010, and insulator 1208 can be threaded into body 1202 once end plate 808 is welded to side wall 826. During final assembly, cathode end plate 808 is positioned to engage feedthrough conductor 812 so that feedthrough conductor 812 extends through hole 1216. Body portion 1202, particularly the region between lengths Lft3 and Lft2, can be crushed both to seal insulator 1208 to feedthrough conductor 812 and to seal the internal threads of body portion 1206 with the external threads of body portion 1212.

[0105] The above-described crushing of body portion 1202 may occur after end plate 808 is connected and sealed to sidewall 826 of pressure vessel 102, as shown in FIG. 14B . The lip of end plate 808, shown in FIG. 10C , mates with lip 1302 of sidewall 826 such that gap 1402 is formed while end plate 808 is inserted into sidewall 826. Gap 1402 may have gap space G while a portion of end plate 808 is inserted into sidewall 826, providing weld points 842 that may effectively seal end plate 808 to sidewall 826. In a specific example, gap G may be approximately 2 mm, and the tapered portions of lips 1302 and 1014 may form a right angle, for example.

[0106] 15A, 15B, and 15C show one example of an anode end cap 804 according to some embodiments of the present disclosure. As shown in FIGS. 15A and 15B, similar to the cathode end cap 808 discussed above, the anode end cap 804 has a t aec Diameter D with a total thickness of 1 aec The anode end cap 804 is formed from a circular disk of metallic material. As shown in Figure 15B, the anode end cap has a lip 1508 that allows the anode end cap 804 to engage with the side wall 826 to form the pressure vessel 102. As shown in Figure 15B, the lip 1508 has a thickness t aec 2 and diameter D aec 2. Insert 1506 slides into the inside of side wall 826 as described above.

[0107] FIG. 15C shows lip 1508 within circle A shown in FIG. 15B. As shown in FIG. 15C, lip 1508 has a length L aec 3 flat portion 1510, and then a total diameter D aec 1 to length L aec 2, tapering down by a length Laec 4. Consequently, the anode end cap 804 can be inserted into the side wall 826, which engages at the flat portion 1510.

[0108] As shown in Figure 15A, a threaded hole 1502 is formed in the center of the anode end cap 804. The threaded hole 1502 has a thread characteristic Th aec1 and total thickness t aec TD less than 1 aec1 Furthermore, the depth t aec 3 and diameter D aec The third hole 1504 is located a distance L from the center of the screw hole 1502 along a line 1514. aec 1. Threaded hole 1502 and alignment hole 1504 are formed on the exterior side of anode end cap 804 of pressure vessel 102. Hole 1504 may be an alignment hole that is positioned in a known orientation with respect to stack 104 inside the vessel and may be known from outside the vessel during assembly. Additionally, end cap 804 may include one or more threaded holes 832, as shown in FIG. 8C , where screws 830 secure end cap 804 through tabs 728 and 708, as discussed above. As shown in FIG. 15A , each of threaded holes 832 may be located on a line 1512 that is perpendicular to line 1514 and also passes through hole 1502. Threaded holes 832 are spaced a distance Laec5 from hole 1502 on either side of line 1514. The threaded hole 832 is all the way to a depth TDaec2 and has a thread type Thaec2.

[0109] In a specific example of the anode end cap 804, the dimensions can be given by Laec1=40.0 mm; Laec2=2.15 mm; Laec3=1.74 mm; Laec4=2.15 mm; Laec5=45.0 mm; Daec1=114.3 mm; Daec2=106.5 mm; Daec3=4.0 mm; taec1=19.25 mm; taec2=4.25 mm; taec3=4.00 mm; Tdaec1=8.0 mm; Thaec1=M6x1 6H; Tdaec2=8.0 mm; and Thaec2=M6x1 / 6H. The anode end cap 804 can be formed from any material compatible with that of the sidewall 826, such as stainless steel, and engages with the sidewall 826 as described above with respect to the cathode end cap 808.

[0110] 16 further illustrates attaching the stack 104 to the anode end cap 804. As shown in FIG. 16, the stack 104 is first bolted to the end cap 804 using bolts 830 that pass through tabs 708 and 728 on the inner and outer portions 702 and 704, respectively, and through spacers 822. The end cap 804 is therefore appropriately drilled and threaded to receive the bolts 830 in threaded holes 832. Furthermore, the anode conductor 116 is then welded to the anode end cap 804 at weld 840.

[0111] 17A and 17B show one example of an isolator 820 according to some embodiments of the present disclosure. The isolator 820 can be any insulating device that can be disposed between the cathode conductor 118 and the cathode end cap 808 through which the feed-through cathode conductor 812 can pass. FIG. 17A shows a view of the isolator 820 facing the cathode conductor 118, while FIG. 17B shows a cross-sectional view taken along line 1714 shown in FIG. 17A. As shown in FIGS. 17A and 17B, the isolator 820 has a diameter D ai 5 and the main thickness L ai 6 insulating material. A through hole 1710 is formed in the center and has a diameter D ai1 and 90° edges ai 17A, the top portion has a larger diameter than the inner portion. As a result, it has an inner diameter Dai2 and a diameter D ai 6, the greater the thickness L ai A protrusion 1712 having a diameter D ai The two central through holes are positioned to receive the anode feedthrough conductor 824. In some examples, the protrusion 1712 may be integrally formed with the isolator 820, while in some examples, the protrusion 1712 is formed separately and has a diameter D ai 1 and D ai The protrusion 1712 may be inserted into the through-hole 1710 using the lip formed between the two. The protrusion 1712 may be adjacent to or in contact with the cathode end cap 808 in some instances, such as when the cathode feedthrough conductor 812 is substantially shielded from the cathode conductor 118 through the feedthrough 815.

[0112] As further shown in FIG. 17A, two through-holes 1702 and 1704 are spaced apart from the center of through-hole 1710 by L ai 17. The through holes 1702 and 1704 are positioned along a centerline perpendicular to line 1714 at a distance of 4. The holes 1702 and 1704 prevent the isolator 820 from blocking the inflow of the electrolyte 126, thus allowing the electrolyte 126 to flow from the fill tube 122 into the container 102. As shown, the through holes 1702 and 1704 are, in some cases, positioned at a 90° ledge D ai Diameter D that can transition to diameter 4 ai 3. As a result, the inner diameter D ai The inner side wall of the through-hole portion 1710 is located at a position of length Lai3 from the center of the through-hole portion 1710.

[0113] 17A, threaded holes 1706 and 1708 may be formed along line 1714. Holes 1706 and 1708 may be appropriately formed to receive bolt 830 through tabs 728 and 708 of frame 204. Holes 1706 and 1708 may therefore be threaded according to parameter Tai. The depth of holes 1706 and 1708 may be determined by a parameter L. ai 17B, ​​a groove 1716 can be formed on the bottom of the isolator 820. The groove 1716 can be L ai Inner diameter of 8 and outer diameter L ai 7 and L ai 7 and is centered over the through-hole portion 1710.

[0114] A specific example of the isolator 820, consistent with other specific examples provided above, may have the following dimensions: L ai 1=45.0mm;L ai 3=36.0mm;L ai 4=40.0mm;L ai 5=32.0mm;L ai 6=14.0mm;L ai 7=11.5mm;T ai =M6x1 6H;D ai 1=12.0mm;D ai 2=10.3mm;D ai 3=8.0mm;D ai 4=10.0mm;D ai 5=106.53 mm; and D ai 6=19.2 mm. The isolator 820 can be any insulating material, for example UHMW plastic.

[0115] 18A and 18B show one example of a spacer 822. As shown, the spacer 822 is cylindrical in shape with a length Las and a diameter Das. The spacer 822 may be formed from any material, for example, stainless steel. In a specific example, the spacer 822 may have the following dimensions: Las = 12.0 mm and Das = 9.5 mm.

[0116] 19A through 19E illustrate a method 1900 for producing a battery 100 according to some embodiments of the present disclosure. As shown in FIG. 19A, the method 1900 begins at step 1902 and proceeds to block 1936, which includes a series of pre-assemblies that may be performed prior to assembly of the battery 100. The pre-assembly steps 1936 may include cathode electrode assembly steps 1904, anode electrode assembly 1906, separator formation 1908, frame component (inner portion / outer portion) assembly 1910, feedthrough assembly 1912, cathode / container assembly 1914, and electrolyte preparation 1916. Each of these steps may be performed in parallel and is not dependent on the completion of the others.

[0117] In a cathode electrode assembly step 1904, the cathode assemblies 500 are assembled as described above with respect to Figures 5A through 5F. As described, cathode material layers 582 are provided, each with a tab 514, and secured to the cathode bus bar 212 by, for example, a resistance spot welding process. As a result of the cathode electrode assembly 1904, a sufficient number of cathode assemblies 500 may be prepared for assembly into the battery 100. Step 1904 is shown in more detail in Figure 19B.

[0118] As shown in FIG. 19B, the cathode electrode assembly step 1904 begins at step 1938, where the cathode material is cut to form the cathode material layer 502 shown in FIGS. 5A-5D. In step 1940, tabs 514 are welded to the cathode material layer 502, if they are not already present with the cathode material sheet. In step 1942, the tabs 514 may be cut to form the registrations 520, 522, and 524 shown in FIG. 5D. In step 1944, the cathode bus bar 212 shown in FIG. 5E is attached to the tabs 514 of multiple layers 502, for example, two layers, to form the cathode assembly 500. The tabs 514 may be spot welded to the two layers 504, for example, to form the cathode assembly 500.

[0119] In anode electrode assembly step 1906, the anode assembly 400 is assembled as described above with respect to Figures 4A-4F. As shown in Figures 4A-4B, anode layers 402 and 420 are formed, the materials are stacked and compressed to form tabs 404, and the anode bus bar 214 is attached to form the anode assembly 400. A sufficient number of anode assemblies 400 can be produced to form the battery 100. The process of forming the anode assembly 400 is further illustrated with respect to Figure 19C.

[0120] As shown in FIG. 19C , step 1906 begins with step 1946. In step 1946, anode material is cut to form layers 402 and 420. Note that layers 402 and 420 may be cut from different sheets of anode material; for example, anode layer 420 may be corrugated while layer 402 is not. In step 1948, anode material layers 402 and 420 are stacked. In one example, the two layers 402 are separated by layer 420. In step 1950, the stacked anode material is crushed to form tab 404, as shown in FIG. 4C . In step 1952, alignment holes 406 and 408 are cut in tab 404, as shown in FIG. 4D . In step 1954, anode bus bar 214, shown in FIG. 4E , is aligned and welded to tab 404 to form anode assembly 400. In step 1956, the anode assembly 400 may be coated, for example, with PTFE. If so, then in step 1958, the anode assembly 400 is oven dried. In some embodiments, this step may take several hours (e.g., 4 hours). In step 1960, the anode assembly 400 may be sintered. Step 1960 may also take several hours (e.g., 7 to 8 hours). At the end of step 1906, the anode assembly 400 is formed.

[0121] In separator formation 1908, separator 110 is formed, as shown in FIGS. 3A and 3B. As discussed with respect to FIGS. 3A and 3B, this involves cutting separator 110 from a sheet of separator material. A sufficient number of separators 110 can be formed to produce battery 100. Separator formation step 1908 is further illustrated in FIG. 19D. As shown in FIG. 19D, in step 1962, the outer shape of separator 110, including blots 304, 306, 308, 310, 312, and 314, is cut from the sheet of separator material. In step 1964, features such as alignment holes 316, 318, 320, 322, 324, and 326 can be formed.

[0122] 7A-7H , inner and outer portions 702, 704 of frame 204 are formed. As discussed above, inner and outer portions 702, 704 may be formed by cutting them from a sheet of metal and bending them to form fingers 706 and 726 and tabs 708 and 728. Alternatively, fingers 706 and 726 may be formed separately and welded to form inner and outer portions 702, 704, as described above. FIG. 19E shows one example of step 1910.

[0123] As shown in FIG. 19E , step 1910 begins with step 1966 cutting the metal sheet to form the components of inner portion 702 and outer portion 704. This may include forming fingers 706 and 726 and tabs 708 and 728. In step 1968, small features may be formed in each of inner portion 702 and outer portion 704, such as hole 740 in finger 726, holes 718 and 738 in tabs 708 and 728, respectively, and other features shown in FIGS. 7A through 7H . In step 1970, the features cut from the metal sheet may be bent into position to form inner portion 702 and outer portion 704, for example, as described above with respect to FIGS. 7A through 7H .

[0124] In step 1912, the cathode feedthrough assembly 802 is formed as described in Figures 9A through 9F. As described, the cathode feedthrough assembly 802 includes a bridge 810 welded to a feedthrough conductor 812.

[0125] In step 1914, a vessel / cathode assembly is formed, as shown in Figures 14A and 14B. In step 1914, the feedthrough body 1202 and fill tube 816 are welded to the cathode end cap 808, and then the end cap 808 is welded to the side wall 826. An example of step 1914 is shown in Figure 19F. As shown in Figure 19F, in step 1972, the base portion 1204 of the body 1202 of the feedthrough 816 is welded to the cathode end cap 808, shown in Figure 14A, relative to the through hole 1010, shown in Figure 10A. In step 1974, the fill tube 816 is welded to the hole 1012 in the cathode end cap 808. In step 1976, the cathode end cap 808 is then welded to the vessel side wall 826, shown in Figure 14B. Finally, in step 1978 , the insulator 1208 of the feedthrough 815 is inserted into the body 1202 of the feedthrough 815 .

[0126] In step 1916, the electrolyte 126 is prepared. The electrolyte 126 may be a KOH electrolyte, as described above.

[0127] Once the components are provided in step 1936, the method 1900 then proceeds to step 1918. In step 1936, as shown in FIG. 6B, the plurality of cathode assemblies 500 formed in step 1904, the plurality of anode assemblies 400 formed in step 1906, the plurality of separators 110 formed in step 1908, and the inner portion 702 and outer portion 704 formed in step 1910 are stacked in a jig 602. In particular, one example of step 1918 is shown in FIG. 19G.

[0128] 19G, step 1918 begins with step 1980, in which the lower portion 222 of the frame 204 is positioned in the jig 602. In some embodiments, for example, the lower portion 222 may be the inner portion 702, while in other embodiments the lower portion 222 may be the outer portion 704. In step 1984, alternating layers of cathode assemblies 500, separators 110, and anode assemblies 400 are positioned on the jig 602. As discussed above, in a particular example, the electrode stack may include twenty (21) anode assemblies 400 (each having two anode material layers 402 and one anode material layer 420) and twenty (20) cathode assemblies 500 (each having two cathode layers 502). The anode assembly 400 and cathode assembly 500 may be separated by a separator 110 formed from one or more separator layers 300 shown in Figures 3A and 3B. In this particular example, the top and bottom layers are anode assemblies 400. As discussed above, in some examples, the top and bottom layers may be separators 110. Finally, in step 1988, the upper portion 220 of the frame 204 is placed over the stacked electrodes on the jig 602. Once all components are positioned on the jig 602, the method 1900 then proceeds from step 1918 to step 1920.

[0129] In step 1920, as shown in FIG. 6C, the jig 602 with the components is positioned in a press 630 and pressure is applied to the stacked components. As shown in FIG. 6C, the jig 602 includes an alignment rod 620 that is inserted into a sleeve 634 of the press 630 to allow pressure to be applied to the stack. In one example, a pressure of 0.58 MPa may be applied, although other pressure levels may also be used. While pressure is being applied in step 1920, the method 1900 proceeds to step 1922.

[0130] In step 1922, as shown in FIG. 6C , the outer fingers 726 of the outer portion 704 are welded to the inner fingers 706 of the inner portion 702 using holes 740 in the outer fingers 726. These welds are shown in FIG. 6C as welds 636. Additionally, the anode busses 214 for each of the anode assemblies 400 are welded together at welds 640 to form the conductors 116, and the cathode busses 212 for each of the cathode assemblies 500 are welded together at welds 638 to form the conductors 118. Once step 1922 is complete, the stack 104 may then be removed from the press 630 and jig 602, and the method 1900 proceeds to step 1924.

[0131] In step 1924, assembly 850 shown in FIG. 8A is formed. An example of step 1924 is shown in FIG. 19H. In step 1990, cathode feedthrough assembly 802 is welded to stack 104, as shown in FIGS. 8A, 8D, 8E, and 8F. As shown, cathode feedthrough assembly 802 includes bridge 810, which is welded within a slot formed by alignment portions 510 in stacked cathode bus bars 212 that form cathode conductor 118. In step 1992, anode end cap 804 is attached to anode conductor 116. An example of this attachment is shown in FIGS. 8C and 16, in which anode conductor 116 is first bolted to tabs 708 and 728 of inner portion 702 and outer portion 704, respectively, and welded to anode conductor 116 at weld 840. Once the assembly 850 is formed in step 1924, the method 1900 may then proceed to final assembly 1926.

[0132] In step 1926, the cathode and can assembly produced in step 1914 and assembly 850 produced in step 1924 may be combined as shown in Figures 8B and 8C. Step 1926 is further illustrated in Figure 19I. As shown in Figure 19I, step 1926 begins with step 1994, where insulator 820 is placed over cathode feedthrough conductor 812 of assembly 802 and bolted to tab 708 of inner portion 702 and tab 728 of outer portion 704, as discussed with respect to Figures 17A and 17B. In step 1996, assembly 850 with insulator 820 in place is inserted through sidewall 826 so that cathode feedthrough conductor 812 extends through feedthrough 815. In step 1998, sidewall 826 is welded to anode end cap 804. From step 1926, the method 1900 proceeds to step 1928.

[0133] In step 1928, the outer body portion 1206 of the body 1202 is crushed or crimped such that the insulator 1208 seals around the cathode feedthrough conductor 812. Step 1928 is accomplished by evenly crimping the body portion 1208 around its circumference to provide an even seal around the cathode feedthrough conductor 812. After step 1928, the pressure vessel 102 is complete. Once step 1928 is complete, the method 1900 then proceeds to step 1930.

[0134] At step 1930, the pressure vessel 102 is leak tested using the fill tube 816. At this step, a pressure test may be performed by pressurizing the pressure vessel 102 to a particular test pressure and monitoring the pressure over time. The pressure vessel 102 may be determined to pass the test if the pressure is held for a set period of time. If the pressure vessel 102 passes the leak test, then the method 1900 proceeds to step 1932.

[0135] In step 1932, the electrolyte 126 produced in the electrolyte preparation step 1916 is added to the pressure vessel 102. One example of step 1932 is shown in FIG. 19J. As shown in FIG. 19J, step 1932 begins with a degassing step 1901. In the degassing step 1901, the pressure vessel 102 is evacuated through the fill tube 816 to allow the interior to degas. In step 1903, the pressure vessel 102 may be flushed with electrolyte 126 one or more times by filling and draining the pressure vessel 102 one or more times through the fill tube 816. The filling and draining may include evacuating the pressure vessel 102 and filling the pressure vessel 102 with electrolyte and then applying a gas at a pressure to drain the pressure vessel 102. In step 1905, the electrolyte 126 is added to the pressure vessel 102 to fill the pressure vessel 102. This may be accomplished by repeatedly evacuating the pressure vessel 102 and adding electrolyte 126, as discussed above, until the pressure vessel 102 is filled with electrolyte 126. In step 1907, the pressure vessel 102, now filled with electrolyte 126, is allowed to sit for a period of time to allow the electrode stack 104 to absorb a sufficient amount of electrolyte 126 for operation of the battery 100. In some embodiments, this step may be long enough to soak the electrode stack 104 with the electrolyte 126. This may take several hours (e.g., about 8 hours) in total, but once the electrode stack 104 contains enough electrolyte 126, step 1932 then proceeds to step 1909, where the excess electrolyte 126 is drained. This may be accomplished by providing hydrogen gas pressure to the fill tube 816 to remove the excess electrolyte 126. In step 1911, the fill tube 816 is sealed to form the completed battery 100. From step 1932, the method 1900 proceeds to step 1934 for electrical testing. The electrical testing in step 1934 may include charging and discharging the resulting battery 100 over multiple cycles and monitoring the performance of the battery 100.

[0136] Aspects of the present disclosure describe metal hydride batteries and their assembly. Various aspects of the invention can include the following aspects.

[0137] Aspect 1: A metal-hydrogen battery comprising: an electrode stack, the electrode stack having alternating anode assemblies and cathode assemblies separated by a separator, each of the anode assemblies including at least one anode layer connected to an anode bus, each of the cathode assemblies including at least one cathode layer connected to a cathode bus, wherein each of the anode buses is electrically and mechanically attached to form an anode conductor, and wherein each of the cathode buses is electrically and mechanically attached to form a cathode conductor; a pressure vessel, the pressure vessel having a sidewall, a cathode end plate, and an anode end plate, the electrode stack inserted within the pressure vessel; and an electrolyte contained within the electrode stack.

[0138] Aspect 2: The metal hydrogen battery of Aspect 1, further comprising: a feedthrough attaching to the cathode end plate; and a cathode feedthrough conductor attaching to the cathode conductor and extending through the feedthrough.

[0139] Aspect 3: A metal-hydrogen battery as described in Aspects 1 to 2, wherein the feedthrough has a body portion attached to the cathode end plate and an insulator portion inserted into the body portion and engaging the cathode feedthrough conductor.

[0140] Aspect 4: The metal hydrogen battery of Aspects 1-3, wherein the body portion is crushed to form a seal between the body portion, the insulator portion, and the cathode feedthrough conductor.

[0141] Aspect 5: The metal hydrogen battery of Aspects 1-4, further comprising an isolator positioned between the cathode conductor and the cathode end plate.

[0142] Aspect 6: The metal hydrogen battery of Aspects 1-5, wherein the anode end plate is directly attached to the anode conductor.

[0143] Aspect 7: The metal hydrogen battery of Aspects 1-6, wherein the anode end plate is welded to the anode conductor.

[0144] Aspect 8: The metal hydrogen battery of Aspects 1 to 7, wherein the electrode stack further comprises a frame surrounding the alternating anode and cathode assemblies, and wherein the electrode stack is welded while the electrode stack is pressed.

[0145] Aspect 9: The metal-hydrogen battery of aspects 1 to 8, wherein the alternating anode and cathode assemblies of the electrode stack include one more anode assembly than cathode assemblies, and the electrode stack has an anode assembly on each side of the electrode stack.

[0146] Embodiment 10: The metal hydride battery of embodiments 1 to 9, wherein the separator comprises one or more separator layers.

[0147] Aspect 11: The metal hydride battery of Aspects 1 to 10, wherein the separator includes a wicking tab.

[0148] Embodiment 12: A method for forming a metal-hydrogen battery, comprising: assembling a plurality of cathode assemblies, each cathode assembly having a cathode bus bar attached to one or more cathode material layers; assembling a plurality of anode assemblies, each anode assembly having an anode bus bar coupled to one or more anode material layers; forming a separator from one or more separator layers; forming a frame inner portion and a frame outer portion, at least one of the frame inner portion and the frame outer portion including a finger connecting the frame inner portion and the frame outer portion; assembling a cathode feedthrough assembly including a bridge welded to a cathode feedthrough conductor; assembling a cathode can assembly including a cathode end cap, a feedthrough connected to the cathode end cap, a fill tube connected to the cathode end cap, and a can sidewall attached to the cathode end cap, the feedthrough including a body and an insulator; and preparing an electrolyte. Thus, the steps include pre-assembling the components of the metal-hydrogen battery; stacking the inner frame portion, the outer frame portion, a separator, an anode assembly, and a cathode assembly in a jig to capture the electrode between the inner frame portion and the outer frame portion; pressing the electrode, the inner frame portion, and the outer frame portion in the jig; attaching the inner frame portion to the outer frame portion using the fingers to form a frame while pressure is applied, attaching the anode bus bars of the plurality of anode assemblies to form anode conductors, and attaching the cathode bus bars of the plurality of cathode assemblies to form cathode conductors, forming an electrode stack; assembling the anode assemblies by attaching the anode end cap to the anode conductor of the electrode stack and attaching the cathode feedthrough assembly to the cathode conductor of the electrode stack; inserting an insulator over the cathode feedthrough conductor;a cathode end cap of the anode assembly attached to the cathode can assembly sidewall; a fill tube of the anode assembly including a fill tube for sealing the insulator of the feedthrough to the cathode feedthrough conductor; a fill tube of the anode assembly including a fill tube for sealing the insulator of the feedthrough to the cathode feedthrough conductor;

[0149] Embodiment 13: The method of embodiment 12, wherein the fill tube extends through the cathode end cap.

[0150] Embodiment 14: The method of embodiments 12 to 13, wherein the step of forming the plurality of anode assemblies comprises: for each anode assembly of the plurality of anode assemblies, forming one or more anode material layers from a sheet of anode material; stacking the one or more anode material layers; crushing ends of the stacked anode material layers to form tabs; and attaching an anode bus bar to the tabs.

[0151] Aspect 15: The method of Aspects 12 to 14, wherein assembling a plurality of cathode assemblies comprises: for each cathode assembly of the plurality of cathode assemblies, forming one or more cathode layers from a sheet of cathode material; attaching a tab to each of the one or more cathode layers; and attaching the tab of the one or more cathode layers to a cathode bus bar.

[0152] Aspect 16: The method described in aspects 12 to 15, wherein the step of assembling the cathode can assembly includes: attaching the body of the feedthrough so that it is aligned with a through hole portion in the cathode end cap; attaching the filling tube to a second through hole portion in the cathode end cap; attaching the can side wall to the cathode end cap; and inserting the insulator of the feedthrough into the body of the feedthrough.

[0153] Embodiment 17: An electrode stack for a hydrogen metal battery, comprising: an electrode stack having alternating anode assemblies and cathode assemblies, the anode assemblies and cathode assemblies separated by separators, each of the anode assemblies including at least one anode layer connected to an anode bus, each of the cathode assemblies including at least one cathode layer connected to a cathode bus, wherein each of the anode buses is electrically and mechanically attached to form an anode conductor, and wherein each of the cathode buses is electrically and mechanically attached to form a cathode conductor.

[0154] Aspect 18: The electrode stack of Aspect 17, wherein the electrode stack further comprises a frame surrounding the alternating anode and cathode assemblies, and the electrode stack is welded while the electrode stack is pressed.

[0155] Embodiment 19: An electrode stack described in embodiments 17 to 18, wherein the alternating anode and cathode assemblies of the electrode stack include one more anode assembly than cathode assemblies, and the electrode stack has an anode assembly on each side of the electrode stack.

[0156] Embodiment 20: The electrode stack of embodiments 17 to 19, wherein the separator comprises one or more separator layers.

[0157] Embodiment 21: The electrode stack of embodiments 17 to 20, wherein the separator includes a wicking tab.

[0158] Aspect 22: A method for forming an electrode stack for a metal-hydrogen battery, comprising: assembling a plurality of cathode assemblies, each cathode assembly having a cathode bus bar attached to one or more cathode material layers; assembling a plurality of anode assemblies, each anode assembly having an anode bus bar coupled to one or more anode material layers; forming a separator from a separator material; forming a frame inner portion and a frame outer portion, at least one of the frame inner portion and the frame outer portion including fingers connecting the frame inner portion and the frame outer portion; forming an electrode stack by: stacking the inner frame portion, the outer frame portion, a separator, an anode assembly, and a cathode assembly to capture the electrode between the inner frame portion and the outer frame portion; pressing the electrode, the inner frame portion, and the outer frame portion; attaching the inner frame portion to the outer frame portion with the fingers while pressure is applied to form a frame, attaching the anode bus bars of the plurality of anode assemblies to form anode conductors, and attaching the cathode bus bars of the plurality of cathode assemblies to form cathode conductors.

[0159] The embodiments of the present invention described herein are not intended to limit the present invention. Those skilled in the art will recognize that many variations and modifications are possible within the scope of the present invention. Accordingly, the present invention is set forth in the following claims.

Claims

1. an electrode stack, the electrode stack having alternating anode assemblies and cathode assemblies separated by separators formed from one or more separator layers, each of the anode assemblies including at least one anode layer connected to an individual anode bus, each of the cathode assemblies including at least one cathode layer connected to an individual cathode bus, wherein each of the individual anode buses from each of the anode assemblies are stacked and electrically and mechanically attached to form an anode conductor, and wherein each of the individual cathode buses from each of the cathode assemblies are stacked and electrically and mechanically attached to form a cathode conductor; a pressure vessel having a sidewall, a cathode end plate, and an anode end plate, the electrode stack inserted within the pressure vessel; and An electrolyte contained within the electrode stack A metal hydride battery comprising:

2. 2. The metal-hydrogen battery of claim 1, wherein the electrode stack further comprises a frame surrounding the alternating anode and cathode assemblies, the frame having a top portion and a bottom portion, the top portion including a first side support extending toward the bottom portion, and the bottom portion including a second side support extending toward the top portion, the first side support and the second side support being welded while the stacked alternating anode and cathode assemblies are pressed together.

3. 1. A method for forming a metal hydride battery, comprising: assembling a plurality of cathode assemblies, each cathode assembly having a respective cathode bus bar attached to one or more layers of cathode material; assembling a plurality of anode assemblies, each anode assembly having a respective anode bus bar coupled to one or more anode material layers; forming a separator from one or more separator layers; forming a frame inner portion and a frame outer portion, at least one of the frame inner portion and the frame outer portion including a finger connecting the frame inner portion and the frame outer portion; assembling a cathode feedthrough assembly including a bridge welded to the cathode feedthrough conductor; assembling a cathode can assembly including a cathode end cap, a feedthrough connected to the cathode end cap, a fill tube connected to the cathode end cap, and a can side wall attached to the cathode end cap, the feedthrough including a body and an insulator; and Preparing the electrolyte pre-assembling the components of the metal hydride battery by: stacking the frame inner portion, the frame outer portion, a separator, an anode assembly, and a cathode assembly to capture an electrode between the frame inner portion and the frame outer portion; pressing the electrode, the frame inner portion, and the frame outer portion; While pressure is applied, attaching the frame inner portion to the frame outer portion using the fingers to form a frame; attaching the individual anode bus bars of the plurality of anode assemblies to form an anode conductor; and attaching the individual cathode bus bars of the plurality of cathode assemblies to form cathode conductors. forming an electrode stack by assembling a stack assembly by attaching an anode end cap to the anode conductor of the electrode stack and attaching the cathode feedthrough assembly to the cathode conductor of the electrode stack; inserting an insulator over the cathode feedthrough conductor; inserting the stack assembly into the can sidewall of the cathode can assembly by inserting the cathode feedthrough conductor through the feedthrough in the cathode end cap; attaching the anode end cap of the stack assembly to the can sidewall of the cathode can assembly; crushing the body of the feedthrough to seal the insulator of the feedthrough to the cathode feedthrough conductor; adding electrolyte to the electrode stack through the fill tube; and sealing the filling tube A method comprising:

4. The steps of forming a plurality of anode assemblies include: For each anode assembly of the plurality of anode assemblies: forming one or more anode material layers from a sheet of anode material; stacking the one or more anode material layers; crushing an end of the stacked anode material layers to form a tab; Attaching a separate anode bus bar to the tab.

4. The method of claim 3, comprising:

5. The steps of assembling a plurality of cathode assemblies include: For each cathode assembly of the plurality of cathode assemblies: forming one or more cathode layers from a sheet of cathode material; attaching a tab to each of the one or more cathode layers; attaching the tabs of the one or more cathode layers to respective cathode bus bars; 4. The method of claim 3, comprising:

6. The steps of assembling the cathode can assembly include: attaching the body of the feedthrough so that it is aligned with a through hole in the cathode end cap; attaching the fill tube to a second through-hole in the cathode end cap; attaching the vessel sidewall to the cathode end cap; and inserting the insulator of the feedthrough into the body of the feedthrough 4. The method of claim 3, comprising:

7. an electrode stack, the electrode stack having alternating anode assemblies and cathode assemblies, the anode assemblies and cathode assemblies separated by separators, each of the anode assemblies including at least one anode layer connected to an individual anode bus, each of the cathode assemblies including at least one cathode layer connected to an individual cathode bus, wherein each of the individual anode buses from each of the anode assemblies are stacked and electrically and mechanically attached to form an anode conductor, and wherein each of the individual cathode buses from each of the cathode assemblies are stacked and electrically and mechanically attached to form a cathode conductor; 1. An electrode stack for a metal-hydrogen battery comprising:

8. 8. The electrode stack of claim 7, further comprising a frame surrounding the alternating anode and cathode assemblies, the frame having a top portion and a bottom portion, the top portion including a first side support extending toward the bottom portion, the bottom portion including a second side support extending toward the top portion, and the first side support and the second side support being welded while the stacked alternating anode and cathode assemblies are pressed.

9. 8. The electrode stack of claim 7, wherein the alternating anode and cathode assemblies of the electrode stack include one more anode assembly than cathode assemblies, the electrode stack having an anode assembly on each side of the electrode stack.

10. 1. A method for forming an electrode stack for a metal hydride battery, comprising: assembling a plurality of cathode assemblies, each cathode assembly having a respective cathode bus bar attached to one or more layers of cathode material; assembling a plurality of anode assemblies, each anode assembly having a respective anode bus bar coupled to one or more anode material layers; forming a separator from a separator material; forming a frame inner portion and a frame outer portion, at least one of the frame inner portion and the frame outer portion including a finger connecting the frame inner portion and the frame outer portion; pre-assembling the components of the metal hydride battery by: stacking the frame inner portion, the frame outer portion, a separator, an anode assembly, and a cathode assembly to capture an electrode between the frame inner portion and the frame outer portion; pressing the electrode, the frame inner portion, and the frame outer portion; While pressure is applied, attaching the frame inner portion to the frame outer portion using the fingers to form a frame; attaching each of the individual anode bus bars of the plurality of anode assemblies to form an anode conductor; and attaching each of the individual cathode bus bars of the plurality of cathode assemblies to form a cathode conductor. forming an electrode stack by A method comprising:

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