Electrochemical cell with elongated-grain anode and controlled anode movement for homogeneous mass loss

Abstract

An aluminum-air electrochemical cell with elongated-grain anode and controlled anode movement for homogeneous mass loss. The aluminum-air electrochemical cell comprises an anode with a grain microstructure having a thickness-to-width aspect ratio of at least 50%, which improves Coulombic efficiency and allows the use of lower-purity aluminum alloys. The anode is configured for motion relative to an electrolyte to promote homogeneous mass loss and improved energy output. Electrochemical mapping and cluster analysis confirm the uniformity and efficacy of current distribution across the anode surface, enabling performance parity or superiority compared to conventional fine-grain high-purity aluminum anodes.

Description

ELECTROCHEMICAL CELL WITH ELONGATED-GRAIN ANODE AND CONTROLLED ANODE MOVEMENT FOR HOMOGENEOUS MASS LOSSBackground

[0001] The present disclosure relates to primary aluminum-air batteries and, more specifically, to batteries incorporating anodes made from elongate-grain aluminum alloys and configured for motion relative to the electrolyte to promote uniform anodic dissolution.

[0002] Conventional aluminum-air batteries use high-purity, fine-grained aluminum anodes to mitigate localized corrosion. However, these materials are expensive, energy-intensive to refine, and have limited thickness due to uneven mass loss during use. Thinner anodes result in more frequent replacements and system downtime. Existing designs also lack efficient solutions for homogenizing corrosion, which negatively impacts power output and cell longevity.

[0003] Typically, a conventional aluminum anode in an aluminum-air primary battery is made of a metal or a metal alloy that has a relatively fine-grained microstructure. Also, the conventional anode is made of a relatively high grade aluminum alloy (e.g., 99.99% Al). The foregoing characteristics are conventionally believed to be required, in order to minimize corrosion of the anode.

[0004] However, due to the processing and refining steps that are required to be taken in order to provide a relatively high aluminum content and a relatively fine-grained microstructure, the conventional anodes are relatively expensive, and carbon intensive.

[0005] The conventional anode in an aluminum-air cell has other disadvantages. For example, the anodes are typically limited to relatively thin profiles because mass loss from the anode in a conventional cell is generally heterogeneous. The unevenly distributed mass loss results in decreased voltage and power output. In order to mitigate this effect, the conventional anodes are relatively thin, and frequent replacement is needed. The relatively frequent shutdowns that are required for anode replacement tend to increase operating costs.

[0006] There is desire to address or mitigate one or more of the defects or deficiencies in aluminum-air batteries.Summary

[0007] An aluminum-air electrochemical cell with elongated-grain anode and controlled anode movement for homogeneous mass loss. The aluminum-air electrochemical cell comprises an anode with a grain microstructure having a thickness-to-width aspect ratio of at least 50%, which improves Coulombic efficiency and allows the use of lower-purity aluminum alloys. The anode is configured for motion relative to an electrolyte to promote homogeneous mass loss and improved energy output. Electrochemical mapping and cluster analysis confirm the uniformity and efficacy of current distribution across the anode surface, enabling performance parity or superiority compared to conventional fine-grain high-purity aluminum anodes.

[0008] The present disclosure provides an electrochemical cell comprising:• An elongate-grain aluminum anode, with grains having an aspect ratio (thickness-to-width or thickness-to-length or both) of >50%, enabling even dissolution.• A cathode assembly and an electrolyte situated between the anode and cathode.• A means of anode motion, such as rotation, to promote uniform exposure to the electrolyte.• The use of commercial-grade aluminum alloys (>87% Al) with acceptable impurity levels.

[0009] This disclosure provides a battery that includes an anode made of a metal that has a microstructure including a number of grains having an aspect ratio of at least 50 per cent of thickness to width or length or both. The anode has one or more exposed surfaces thereon. The battery also includes a cathode in contact with the second side of the cathode assembly. The cathode assembly permits the cathode to react with the electrolyte.

[0010] The battery also includes a cathode assembly with a first side and an opposed second side thereof, and an electrolyte that is between the cathode assembly and the anode. The electrolyte is in contact with the first side of the cathode assembly and the exposed surface of the anode. The exposed surface may be movable relative to the electrolyte.

[0011] Supporting electrochemical maps (e.g., corrosion potential vs. mapping direction) and PDP clustering analysis demonstrate homogeneity of current distribution and reduction of trenching, particularly in hot-pressed specimens is also provided.Brief Description of the Drawings

[0012] FIG. 1 illustrates is a schematic diagram of an embodiment of a battery of the disclosure.

[0013] FIG. 2 illustrates a schematic diagram showing elongate grains in a microstructure, indicating elongate grains with defined width and thickness.

[0014] FIG. 3 illustrates PDP cluster distribution graphs showing uniform electrochemical profiles.

[0015] FIG. 4 illustrates SEM cross-sectional images of as-cast and hot-pressed aluminum alloys, showing differences in corrosion morphology.Detailed Description

[0016] Various embodiments are described hereinafter. It should be noted that the specific embodiments are not intended as an exhaustive description or as a limitation to the broader aspects discussed herein. One aspect described in conjunction with a particular embodiment is not necessarily limited to that embodiment and can be practiced with any other embodiment(s).

[0017] As used herein, "about" will be understood by persons of ordinary skill in the art and will vary to some extent depending upon context in which it is used. If there are uses of the term which are not clear to persons of ordinary skill in the art, given context in which it is used, "about" will mean up to plus or minus 10% of the particular term.

[0018] The use of the term "a" and "an" and "the" and similar referents in the context of describing the elements (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Recitation of ranges of values herein are merely intended to serve as shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. "such as") provided herein, is intended merely to better illuminate the embodiments and does not pose a limitation on the scope of the claims unless otherwise stated. No language in the specification should be construed as indicating any non-claimed element as essential.

[0019] In the attached drawings, reference numerals designate corresponding elements throughout. Reference is made to FIGURES 1 and 2 to describe an embodiment of a battery in accordance with the invention indicated generally by the numeral 20. As will be described, in the example illustrated, the battery 20 is an aluminum-air battery.

[0020] In one embodiment, the battery 20 preferably includes an anode 22. The anode 22 preferably includes a metal having a microstructure 24 (FIG. 2) with a number of grains 26 having an aspect ratio of at least 50 per cent of thickness to width or length or both of the grain. As will be described, the anode 22 preferably has one or more exposed surfaces 28 thereon.

[0021] For the purposes hereof, "metal" is understood to refer to an element, or an alloy that includes more than one element. For instance, aluminum alloy that is commercially available is referred to as a "metal", for the purposes hereof, and an anode that is referred to as "aluminum" may be an aluminum alloy.

[0022] FIG. 1 illustrates is a schematic diagram of an embodiment of a battery of the disclosure. According to FIG. 1 a schematic of a battery of the aluminum-air battery system is shown illustrating a rotating anode, electrolyte channels, and a cathode assembly.

[0023] As can be seen in FIG. 1, the battery 20 preferably also includes a cathode assembly 30 with a first side 32 and an opposed second side 34 thereof. Preferably, the battery 20 also includes an electrolyte 36 in contact with the first side 32 of the cathode assembly 30 and the one or more exposed surfaces 28 of the anode 22. As will be described, the anode 22 preferably is movable relative to the electrolyte, for homogeneous, or substantially homogeneous, mass loss over the exposed surface 28.

[0024] Preferably, a cathode 38 is provided by oxygen, in its gas phase (FIG. 1). It is also preferred that, the cathode assembly 30 includes a gas diffusion electrode. Those skilled in the art would be aware of suitable gas diffusion electrodes. In one embodiment, the gas diffusion electrode of the cathode assembly 30 preferably includes a matrix of hydrophilic and hydrophobic materials defining pores therein (not shown), to provide a relatively large surface area in the cathode assembly 30. From the foregoing, it can be seen that the cathode assembly 30 has an oxygen-rich gaseous side 31A thereof (proximal to the second side 34 of the cathode assembly 30), and a liquid electrolyte side 31B thereof (proximal to the first side 32 of the cathode assembly 30). Those skilled in the art would be aware of suitable hydrophilic and hydrophobic materials. The cathode assembly 30 may also include such conventional structural elements,e.g., separators and / or membranes (not shown), as are needed in order to hold the material therein in position between the cathode 38 and the electrolyte 36.

[0025] Those skilled in the art would appreciate that the cathode assembly 30 preferably also includes a metal current collector (not shown). As is known in the art, the cathode assembly 30 preferably also includes a catalyst (not shown), to facilitate the reduction of oxygen into hydroxide ions in or at the cathode assembly 30 and which, in the electrolyte 32, can react with the aluminum of the anode 22 to form hydrated aluminum oxide (AI(OH)3).

[0026] Those skilled in the art would also appreciate that the battery 20 preferably also includes a means for completing the battery circuit. For example, in one embodiment, the battery 20 preferably includes a rotating contact, e.g., a slip ring 40 (FIG. 1).

[0027] Those skilled in the art would be aware that the oxygen (i.e., the cathode 38) may be provided by any suitable source thereof, e.g., ambient air. The electrolyte may be any suitable aqueous electrolyte (e.g., aqueous solutions of sodium hydroxide, potassium hydroxide, or sodium chloride), as would be known to those skilled in the art.

[0028] From the foregoing, and as is known in the art, while the battery 20 is operating, the metal of the anode 22 that is in contact with the electrolyte is consumed in the redox reaction, i.e., oxygen is reduced at the cathode assembly 30, and the metal of the anode 22 is oxidized. As noted above, the reactions tend to be heterogeneous over the exposed surface 28.

[0029] Accordingly, in one embodiment, the anode 22 preferably is movable relative to the electrolyte 34, in order that the mass loss may be homogeneous, or substantially homogeneous, over the exposed surface 22.

[0030] The movement of the anode may be effected by any suitable means. For example, as disclosed in U.S. Patent No 10,978,578, an anode disc may be mounted to a central shaft defining an axis about which the anode disc is rotatable by a motor that is operatively connected with the shaft, to rotate the anode disc about the central axis.

[0031] It will be understood that, as shown in FIG. 1, the anode 22 is rotatable about an axis "X", to move the anode 22 relative to the electrolyte 32. Such rotation has been found to result in an even mass flow rate in the electrolyte and a viscous shear force, to promote homogeneous mass transfer of the reactantsand the products. It will also be understood that the shaft and the motor are omitted from FIG. 1 for clarity of illustration.

[0032] Although the embodiment of the primary cell illustrated in FIG. 1 is configured for rotation of the anode 22 relative to the electrolyte 36, it will be understood that any suitable movement of the anode 22 relative to the electrolyte 36 may be utilized.Anode Microstructure and Elongate Grains

[0033] As noted above, it has been determined that, surprisingly, the metal of anode 22 may have the microstructure 24 that is schematically illustrated in FIG. 2. In FIG. 2, a sample block of aluminum is schematically illustrated, at a large scale for clarity of illustration. FIG. 2 illustrates a schematic diagram showing elongate grains in a microstructure, indicating elongate grains with defined width and thickness.

[0034] In the example illustrated in FIG. 2, for instance, a sample 37 includes grains 26 that are elongate, i.e., they are generally longer or wider than they are thick or both. For example, as illustrated, the sample block 37 has a top surface 42 defining a plane, on which the widths and thicknesses of the respective grains can be seen. As an example, a grain identified as "G", as exposed on the top surface 42, has a width (in the direction identified as "W") and a thickness (in the direction identified as "T") (Fig. 2). As illustrated, the grains 26 are generally elongate, i.e., for the grains exposed at the top surface 42, the width exceeds the thickness. It has been found that the battery 20 operates with high Coulombic efficiency when the surface of the anode in contact with the electrolyte has a microstructure similar to that as illustrated on the top surface 42. It is preferred that the ratio of thickness to width, or of thickness to length, is at least approximately 50%.

[0035] As shown in FIG. 2, the anode 22 includes a metal or metal alloy with a unique elongate grain structure 24. Grains 26 have a thickness-to-width (T / W) ratio of > 0.5, indicating that the grains are not equiaxed but stretched or compressed in one or two dimensions. This anisotropic grain structure has been found to promote homogeneous anodic dissolution and enhance Coulombic efficiency, especially when the anode is set in motion relative to the electrolyte.

[0036] In testing, where the microstructure of the anode is as described above, Coulombic efficiencies above 90% have been demonstrated. In view of the prior art, these results are surprising andcounterintuitive. It will be understood that, in this context, Coulombic efficiency is determined by comparing the results based on stoichiometric values to actual values.Microstructure and Performance Justification

[0037] According to the disclosure experimental analysis and testing confirms that aluminum alloy anodes with high aspect ratio aligned grains exhibit higher uniformity in corrosion potential and lower variability in PDPs compared to alternatives.

[0038] Testing confirmed that high aspect ratio aluminum anodes with elongate grains produced:• Uniform Potential Dynamic Profiles (PDPs) across the surface (FIG. 3);• Minimal corrosion potential variation across the mapping direction (FIG. 5);• Reduced trenching and smoother corrosion fronts in SEM analysis (FIG. 4);• Preferential corrosion resistance due to favorable grain orientation (EBSD-supported, not shown).

[0039] Furthermore, PDP cluster analysis shows that cluster 1 dominates in early line recordings, indicating consistency in electrochemical performance across the tested area. FIG. 3 illustrates PDP cluster distribution graphs showing uniform electrochemical profiles. According to FIG. 3, the diagram illustrates performing hot-pressing on the 2370 alloy has for effect to increase greatly the anode energy density while retaining most of its power density when comparted to as-cast. Task 1 is highlighted as c2370 and hp2370.

[0040] According to FIG. 3, The first set of patterned electrochemical landings produced PDP (Potential Dynamic Profile) clusters with distinct characteristics. Clustering analysis revealed the dominance of stable Cluster 1 PDPs early in the reaction sequence, while spatial mapping showed tightly grouped corrosion potential values (-1.2V to -1.5V), indicating a consistent anodic response. The dominance of Cluster 1 indicates a consistent electrochemical response, especially in high aspect ratio aluminum samples. This suggests a high degree of electrochemical homogeneity, which aligns with the objective of uniform anodic dissolution.

[0041] High aspect ratio anodes showed fewer intermetallic trenching effects compared to as-cast samples, as shown in side-by-side SEM BSE images. Electron Backscatter Diffraction (EBSD) - based etching revealed that aligned grains limited irregular dissolution, supporting the advantage of controlling grainstructure during manufacture. These findings enable the use of less refined, lower-cost aluminum alloys (down to ~87% Al), reducing production costs while achieving Coulombic efficiencies over 90%.Corrosion Potential Mapping

[0042] FIG. 4 illustrates SEM cross-sectional images of alternatives and high aspect ratio aluminum alloys, showing differences in corrosion morphology. According to FIG. 4, spatial maps of corrosion potential vs. position show minimal variance along the mapping direction in hot-pressed alloys is shown by backscattered electron imaging (BSE).

[0043] According to FIG. 4, the as cast surface is much rougher than the high aspect ratio surface. The as cast surface shows much more corrosion around the eutectic precipitates. The aluminum phase shows crater like morphologies, with smaller "craters" observed for the high aspect ratio.

[0044] According to FIG. 4, the data demonstrates the following:• Narrow corrosion potential bands (approx. -1.3 to -1.5 V)• Spatial continuity, with few disruptive pits or local breakdowns

[0045] According to FIG. 4, the mapping direction is aligned with uniform corrosion potential that supports homogeneity induced by elongated grains and mechanical motion. This uniformity supports the rotational design of the anode by continuously changing which part of the elongate grain face is exposed to fresh electrolyte, the system maintains performance consistency.Microstructure-Specific Corrosion Behavior

[0046] These findings validate that microstructural control via forging, hot pressing, rolling or mechanical deformations allows predictable electrochemical performance. The relatively uniform PDPs in elongate- grain structures show fewer localized peaks, enhancing lifespan and efficiency.SEM Cross-Section of Corrosion Morphology

[0047] According to the disclosure, test data further shows potentiostatic polarization at -1.1V to -1.3V vs. Hg / HgO reveals the following:Alternative samples: includes non high aspect ratio grain and / or equixed samplesHigh aspect ratio samples: had smoother attack patterns with reduced trenching

[0048] According to the disclosure, high aspect ratio BSE images revealed suppressed trenching and uniform degradation, ideal for consistent anodic performance. This supports the disclosure's claim that elongate grains— especially in high aspect ratio configurations— improve surface stability during oxidation. The smoother surfaces contribute to a more controlled and even reaction front, especially when the anode rotates.Topographic Etching From EBSD Data

[0049] According to further aspects of the disclosure, Electron Backscatter Diffraction (EBSD) analysis of aluminum alloy etched in 4M NaOH at 37°C revealed the following:• Grain-orientation dependent corrosion• Preferential attack on certain orientations, emphasizing the need for grain alignment

[0050] Experimental data justifies the use of elongate grains whereby aligned structures limit unpredictable etching and reduce uneven mass loss, particularly when moving relative to the electrolyte.Synthesis and Mechanism

[0051] According to the disclosure, it is proposed that the rotation of an elongate-grain aluminum alloy anode in a flowing electrolyte yields:• Uniform exposure of active sites (due to motion)• Predictable reaction behavior (due to grain and sub grain alignment)• Stable Coulombic efficiency (>90%) even at aluminum purities ~87%• Feasibility for use in scalable primary battery systemsMaterials

[0052] According to the disclosure, the following are materials used in this disclosure:• Aluminum alloys with >87% Al content.• Acceptable but not limited to alloying elements: Mg2Si, Fe, Zn, Cu.Suitable processes to produce elongate grains include hot pressing and forging, rolling, extrusion, etc.Advantages

[0053] According to the disclosure, the following is a list of benefits or advantages of the system:• Lower-cost aluminum alloys can be used without sacrificing efficiency.• Improved Coulombic efficiencies (>90%) despite higher impurity levels.• Reduced carbon footprint due to use of less-refined materials.• Longer operational cycles due to reduced anode replacement frequency.

[0054] Those skilled in the prior art would be aware of techniques that may be utilized to produce a microstructure with elongate grains. For instance, the elongate grains may be produced by subjecting the metal of the anode to one or more processes or with controlled solidification, e.g., forging.

[0055] In one embodiment, the metal alloy may include at least approximately 89 per cent aluminum. The Coulombic efficiencies of more than 90% have been achieved with anodes including commercial aluminum alloys with impurities, to about 87% aluminum. It is believed that commercial aluminum alloys with less than 87% aluminum may be utilized, with acceptable Coulombic efficiency. This is also surprising, and counterintuitive, in view of the prior art.

[0056] The materials with approximately 87% aluminum, or more, are generally available aluminum, including typical commercial alloying elements and impurities. These are less expensive than the aluminum alloys with high aluminum content, and microstructures generally with small grain sizes. Because less expensive and less carbon-intensive materials may be used for efficient generation of electricity in the battery 20 of the invention, significant cost and environmental advantages can be achieved with the Applicant's invention.

[0057] It is believed that significantly improved performance may be achieved in the same way with other metals. In use, the anode 22 is mounted for rotation about the axis "X", driven by a motor (not shown). As indicated in FIG. 1, the electrolyte 36 preferably is directed into a space between the exposed surface 28 and the first side 32 of the cathode assembly 30, and the electrolyte 36 exits therefrom at a controlled rate. The cathode 38 may be provided from ambient air, or otherwise.

[0058] According to the disclosure, the electrolyte may be an aqueous NaOH or KOH solution or other aqueaous conductive electrolyte. The anode and cathode are arranged so that oxygen is reduced at the cathode and the aluminum anode oxidizes, forming aluminum hydroxide.

[0059] According to the disclosure, rotation of the anode relative to the electrolyte enhances mass transfer and reduces localized depletion, enabling even anodic dissolution and mitigating non-uniform pitting or trenching.

[0060] According to the disclosure, a battery is disclosed. The battery comprises at least one anode comprising a metal having a microstructure comprising a plurality of grains having an aspect ratio of at least 50 per cent of thickness to width or length or both, the anode comprising at least one exposed surface thereon, a cathode assembly comprising a first side and an opposed second side thereof, an electrolyte in contact with the first side of the cathode assembly and said at least one exposed surface to permit the anode to react with the electrolyte, wherein said at least one exposed surface is movable relative to the electrolyte, and a cathode in contact with the second side of the cathode assembly, wherein the cathode assembly permits the cathode to react with the electrolyte.

[0061] According to the disclosure, the plurality of grains of the battery further comprising a plurality of subgrains wherein a subgrain is a region within the grain that has a misorientation compared to the rest of the grain. The metal alloy comprises at least 87 per cent aluminum.

[0062] According to the disclosure, the anode of the battery is rotatable about an axis. The microstructure of the battery is produced by mechanical deformation, hot pressing or forging or rolling.

[0063] According to the disclosure, the cathode of the battery comprises a gas diffusion electrode. The electrolyte of the battery comprises an aqueous sodium hydroxide solution. The aluminum alloy includes any of magnesium, silicon, iron, zinc, or copper. The electrolyte flows through a channel between the anode and cathode assembly.

[0064] According to the disclosure, the battery further comprising a slip ring or rotating contact to provide electrical connection during anode motion. The cathode of the battery is derived from ambient atmospheric oxygen.

[0065] According to the disclosure, the microstructure of the battery is produced by additive manufacturing, laser sintering, or electrochemical deposition. The microstructure of the battery is formed by directional solidification followed by thermomechanical processing.

[0066] According to the disclosure, the battery further comprises an anode comprising a metal having a microstructure comprising a plurality of grains having an aspect ratio of at least 50 per cent of thickness to width or length or both, wherein the aluminum content is less than 99.7%. The orientation of the grain or subgrain is substantially aligned parallel to a reaction surface.

[0067] According to the disclosure, a method of manufacturing an aluminum anode for a battery, the method comprising the steps of solidifying molten aluminum to form an aluminum anode and mechanically deforming the aluminum anode, wherein the aluminum anode is produced having a grain aspect ratio of at least 50 per cent of thickness to width or length or both, wherein the orientation of the grains is substantially aligned parallel to the reaction surface .

[0068] According to the disclosure, the step of mechanically deforming the aluminum anode of the method further comprises heat treatment or thermomechanical deformation. Manufacturing an aluminum anode is configured for supporting rolling, extrusion, squeeze casting, forging or hot pressing. The microstructure of the method is formed by directional solidification followed by thermomechanical processing.

[0069] According to the disclosure, a metal-air anode is disclosed. The metal-air anode comprises a metal having a microstructure comprising a plurality of grains having an aspect ratio of at least 50 per cent of thickness to width or length or both. The orientation of the grain of the metal-air anode is substantially aligned parallel to the reaction surface. The metal-air anode comprises aluminum in the range of <90% aluminum to <99.7% aluminum.

[0070] It will be appreciated by those skilled in the art that the invention can take many forms, and that such forms are within the scope of the invention as claimed. The scope of the claims should not be limited by the preferred embodiments set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole.

[0071] While certain embodiments have been illustrated and described, it should be understood that changes and modifications can be made therein in accordance with ordinary skill in the art without departing from the technology in its broader aspects as defined in the following claims.

[0072] The embodiments, illustratively described herein, may suitably be practiced in the absence of any element or elements, limitation or limitations, not specifically disclosed herein. Thus, for example, the terms "including", "containing", etc. shall be read expansively and without limitation. Additionally, the terms and expressions employed herein have been used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalent of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the claimed technology.

[0073] The present disclosure is not to be limited in terms of the particular embodiments described in this application. Many modifications and variations can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. Functionally, equivalent methods and compositions within the scope of the disclosure, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the claims. The present disclosure is to be limited only by the terms of the claims, along with the full scope of equivalents to which such claims are entitled. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.

[0074] In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.

[0075] As will be understood by one skilled in the art, for any and all purposes, particularly in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. As will be understood by one skilled in the art, all language such as "up to", "at least", "greater than", "less than", and the like, include the number recited and refer to ranges which can be subsequently broken down into subranges. Finally, as will be understood by one skilled in the art, a range includes each individual member.

[0076] Portions of this application, including the specification and / or claims, may have been drafted using Al-assisted tools under the direction and supervision of a human practitioner. All inventive contributions are attributable to the listed inventors.

[0077] All publications, patent applications, issued patents, and other documents referred to in this specification are herein incorporated by reference as if each individual publication, patent application, issued patent, or other document was specifically and individually indicated to be incorporated by reference in its entirety. Definitions that are contained in text incorporated by reference are excluded to the extent that they contradict definitions in this disclosure.

Claims

ClaimsWhat is claimed:

1. A battery comprising: at least one anode comprising a metal having a microstructure comprising a plurality of grains having an aspect ratio of at least 50 per cent of thickness to width or length or both, the anode comprising at least one exposed surface thereon; a cathode assembly comprising a first side and an opposed second side thereof; an electrolyte in contact with the first side of the cathode assembly and said at least one exposed surface to permit the anode to react with the electrolyte, wherein said at least one exposed surface is movable relative to the electrolyte; and a cathode in contact with the second side of the cathode assembly, wherein the cathode assembly permits the cathode to react with the electrolyte.

2. The battery according to claim 1 wherein the plurality of grains further comprising a plurality of subgrains wherein a subgrain is a region within the grain that has a misorientation compared to the rest of the grain.

3. The battery according to claim 1 in which the metal alloy comprises at least 87 per cent aluminum.

4. The battery of claim 1, wherein the anode is rotatable about an axis.

5. The battery of claim 1, wherein the microstructure is produced by mechanical deformation, hot pressing or forging or rolling.

6. The battery of claim 1, wherein the cathode comprises a gas diffusion electrode.

7. The battery of claim 1, wherein the electrolyte comprises an aqueous sodium hydroxide solution.

8. The battery of claim 3, wherein the aluminum alloy includes any of magnesium, silicon, iron, zinc, or copper.

9. The battery of claim 1, wherein the electrolyte flows through a channel between the anode and cathode assembly.

10. The battery of claim 1, further comprising a slip ring or rotating contact to provide electrical connection during anode motion.

11. The battery of claim 1, wherein the cathode is derived from ambient atmospheric oxygen.

12. The battery of claim 1, wherein the microstructure is produced by additive manufacturing, laser sintering, or electrochemical deposition.

13. The battery of claim 1, wherein the microstructure is formed by directional solidification followed by thermomechanical processing.

14. The battery of claim 1, further comprising an anode comprising a metal having a microstructure comprising a plurality of grains having an aspect ratio of at least 50 per cent of thickness to width or length or both, wherein the aluminum content is less than 99.7%.

15. The battery of claim 2, wherein the orientation of the grain or subgrain is substantially aligned parallel to a reaction surface.

16. A method of manufacturing an aluminum anode for a battery, the method comprising the steps of: solidifying molten aluminum to form an aluminum anode; and mechanically deforming the aluminum anode; wherein the aluminum anode is produced having a grain aspect ratio of at least 50 per cent of thickness to width or length or both, wherein the orientation of the grains is substantially aligned parallel to the reaction surface .

17. The method of claim 16, wherein the step of mechanically deforming the aluminum anode further comprises heat treatment or thermomechanical deformation.

18. The method of claim 16, wherein manufacturing an aluminum anode is configured for supporting rolling, extrusion, squeeze casting, forging or hot pressing.

19. The method of claim 16, wherein the microstructure is formed by directional solidification followed by thermomechanical processing.

20. A metal-air anode comprising a metal having a microstructure comprising a plurality of grains having an aspect ratio of at least 50 per cent of thickness to width or length or both.

21. The metal-air anode of claim 20, wherein the orientation of the grain is substantially aligned parallel to the reaction surface.

22. The metal-air anode of claim 20, wherein the metal-air anode comprises aluminum in the range of <90% aluminum to <99.7% aluminum.

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