DESC:FIELD OF THE INVENTION
[001] The invention relates to metal alloy compositions and the process of preparing the same. More particularly, the invention relates to a process of preparing a corrosion resistant aluminum alloy composition and aluminum alloy prepared therefrom. The invention also relates to the aluminum alloy anode and aluminum-air battery based on the aluminum alloy anode.

BACKGROUND OF THE INVENTION
[002] Metal alloy is a substance that combines more than one metal or mixes a metal with other non-metallic elements. Metal alloys are useful as electrodes in advanced energy storage and conversion applications. Both structure and composition can play an important role in determining the resulting materials properties.
[003] However, due to higher corrosion rates, the efficiency of the battery decreases over time, resulting in reduced performance. Accordingly, it is believed that by reducing the amount of corrosion in metal alloy, more electrode material will be available to participate in the electrode reaction, contributing to the longevity and production of electrical energy by the electrochemical cell.
[004] Aluminum is well known to have a relatively high electrochemical capacity, and therefore is highly attractive for use in advanced energy storage and conversion applications, such as aluminum-air batteries.
[005] Further, aluminum alloys are widely used in various advanced energy storage and conversion applications due to their high strength to weight ratio and anti-corrosion properties. However, very high purity aluminum alloys are generally used for such applications, requiring high corrosion resistance properties with low amounts of impurities such as iron and silicon.
[006] In an aluminum-air battery, energy is produced by the oxidation of aluminum in an aqueous electrolyte in the presence of oxygen from air. Energy densities of practical aluminum-air batteries are in the range of 3500-4000 Wh/Kg and require the use of very high purity aluminum with low amounts of impurities such as iron and silicon.
[007] Current anode alloy products for aluminum-air batteries use high purity aluminum with less than 50 ppm of iron (Fe) or silicon (Si) and also use exotic alloying elements in aluminum such as gallium (Ga), indium (In), tin (Sn) or zinc (Zn) to promote formation of passive films for improving corrosion resistance.
[008] The production of such high purity aluminum described above requires additional refining steps which add to the cost of production of these alloys. However, such high purity aluminum alloy grades are expensive. Also, alloying elements to improve corrosion resistance such as gallium (Ga), indium (In), tin (Sn) or zinc (Zn) are expensive and add to the cost of the alloys which leads to still higher costs. Hence, there is great value in moving towards the use of commercial grade aluminum with high iron and silicon impurities and yet achieving significantly improved corrosion resistance properties.
[009] Accordingly, there is a need for a corrosion resistant aluminum alloy composition and a process of preparing the same that achieves the desired corrosion resistance and performance for advanced energy storage and conversion applications, particularly in the aluminum-air battery applications in a convenient and cost-effective manner.

SUMMARY OF THE INVENTION

[010] In one aspect, the present invention relates to an aluminum alloy composition comprising 0.005 to 0.1 %wt/wt of silicon (Si), 0.005 to 0.1 %wt/wt of iron (Fe), 0 to 0.1 %wt/wt of manganese (Mn), 0.5 to 6.0 %wt/wt of magnesium (Mg), 0 to 0.1 %wt/wt of copper (Cu), 0 to 0.1 %wt/wt of zinc (Zn), 0 to 0.1 %wt/wt of chromium (Cr), 0 to 0.1 %wt/wt of titanium (Ti), 0 to 0.05 %wt/wt of others and balance is aluminum.
[011] In another aspect, the invention relates to a process for preparing an aluminum alloy composition comprising the steps of: (a) solutionizing heat treatment of a commercial grade aluminum alloy at a predetermined temperature and time; and (b) quenching the heat-treated alloy at a predetermined cooling rate to produce the aluminum alloy composition, wherein the solutionizing heat treatment includes soaking the material at a predetermined temperature to dissolve the iron (Fe) and silicon (Si) based particles of the aluminum alloy.
[012] In another aspect, the invention is directed to a method of preparing an aluminum alloy anode comprising the following steps: (a) aluminum billets of suitable size are cast by adding charge after calculation as per the requirement in an induction furnace, (b) adding alloying elements after the aluminum charge is completely melted, (c) casting the melt into molds followed by manufacturing flats of predetermined sizes, (d) solutionizing heat treatment of the flats at predetermined temperature, (e) quenching the heat-treated flats at a predetermined cooling rate to produce the aluminum alloy anode.
[013] In a further aspect, the invention is related to an aluminum-air battery comprising an aluminum alloy anode in accordance with the present invention, a cathode, and an electrolyte.
[014] In a further aspect, the invention is directed to a method of preparing an aluminum-air battery.

BRIEF DESCRIPTION OF THE DRAWINGS
[015] Reference will be made to embodiments of the invention, examples of which may be illustrated in accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in the context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
Figure 1 shows Particle Size Distribution (%Area fraction) of HILBP0204 and HILBP0205 in as cast and Heat -treated condition.
Figure 2 shows SEM images of Particle Size Distribution (%Area fraction) before and after heat treatment for HILBP02024 a) SEM image of as cast sample at 600X and b) SEM image of heat-treated sample at 600X.
Figure 3 shows Energy utilization graph of conventional Al-Mg alloy with very high purity compared to HILBP0204 and HILBP0205.
Figure 4 shows SEM images of Particle Size Distribution (%Area fraction) before and after heat treatment for BC-7 (a) Before heat treatment and (b) After heat treatment
Figure 5 shows SEM images of Particle Size Distribution (%Area fraction) before and after heat treatment for BC-8 (a) Before heat treatment and (b) After heat treatment

DETAILED DESCRIPTION OF THE INVENTION
[016] Before the compositions and formulations of the present invention are described, it is understood that this invention is not limited to particular compositions and formulations described, since such compositions and formulations may, of course, vary. It is also to be understood that the terminology used herein is not intended to be limiting since the scope of the present invention will be limited only by the appended claims.
[017] The terms “comprising”, “comprises” and “comprised of” as used herein are synonymous with “including”, “includes” or “containing”, “contains”, and are inclusive or open-ended and do not exclude additional, non-recited members, elements, or method steps. It will be appreciated that the terms “comprising”, “comprises” and “comprised of” as used herein comprise the terms “consisting of”, “consists” and “consists of”.
[018] Furthermore, the terms “first”, “second”, “third” or “(a)”, “(b)”, “(c)”, “(d)” etc. and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein. In case the terms “first”, “second”, “third” or “(A)”, “(B)” and “(C)” or “(a)”, “(b)”, “(c)”, “(d)”, “i”, “ii” etc. relate to steps of a method or use or assay there is no time or time interval coherence between the steps, that is, the steps may be carried out simultaneously or there may be time intervals of seconds, minutes, hours, days, weeks, months or even years between such steps unless otherwise indicated in the application as set forth herein above or below.
[019] In the following passages, different aspects of the present invention are defined in more detail. Each aspect so defined may be combined with any other aspect or aspects unless clearly indicated to the contrary. In particular, any feature indicated as being preferred or advantageous may be combined with any other feature or features indicated as being preferred or advantageous.
[020] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to a person skilled in the art from this disclosure, in one or more embodiments. Furthermore, while some embodiments described herein include some, but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention and form different embodiments, as would be understood by those in the art. For example, in the appended claims, any of the claimed embodiments can be used in any combination.
[021] Furthermore, the ranges defined throughout the specification include the end values as well, i.e., a range of 1 to 10 implies that both 1 and 10 are included in the range. For the avoidance of doubt, the applicant shall be entitled to any equivalents according to applicable law.
[022] In an aspect, the present disclosure relates to an aluminum alloy composition designed to provide a corrosion-resistant aluminum alloy anode that enhances the efficiency and longevity of aluminum-air batteries.
[023] In one embodiment, the aluminum alloy composition comprises:
- 0.005 to 0.1 %wt/wt of silicon (Si)
- 0.005 to 0.1 %wt/wt of iron (Fe)
- 0 to 0.1 %wt/wt of manganese (Mn)
- 0.5 to 6.0 %wt/wt of magnesium (Mg)
- 0 to 0.1 %wt/wt of copper (Cu)
- 0 to 0.1 %wt/wt of zinc (Zn)
- 0 to 0.1 %wt/wt of chromium (Cr)
- 0 to 0.1 %wt/wt of titanium (Ti)
- 0 to 0.05 %wt/wt others; and the balance is aluminum (Al).
[024] In another embodiment, the aluminum alloy composition comprises:
- 0.005 to 0.03 %wt/wt of silicon (Si)
- 0.005 to 0.03 %wt/wt of iron (Fe)
- 0 to 0.01 %wt/wt of manganese (Mn)
- 0.5 to 3.0 %wt/wt of magnesium (Mg)
- 0 to 0.01 %wt/wt of copper (Cu)
- 0 to 0.01 %wt/wt of zinc (Zn)
- 0 to 0.01 %wt/wt of chromium (Cr)
- 0 to 0.01 %wt/wt of titanium (Ti)
- 0 to 0.05 %wt/wt others; and the balance is aluminum (Al).
[025] The aluminum alloy composition, as described, incorporates alloying elements that contribute to the overall performance and functionality of the material. Together, these elements work synergistically to provide a corrosion-resistant, high-strength aluminum alloy anode suitable for advanced energy storage and conversion applications. By keeping the iron and silicon content low, the alloy achieves a higher level of purity and stability, which is essential for maintaining long-term performance.
[026] As used herein the term “others” of the aluminum alloy composition refers to trace elements present within the aluminum matrix that are not in control during casting and are a part of the material that are present from the primary aluminum melting as impurities for e.g. vanadium, boron, gallium, lead etc.
[027] The aluminum alloy composition generates high energy density when used as anode for aluminum-air battery. The high energy density achieved is greater than 4000 Wh/Kg, preferably 4.3KWh/kg.
[028] Another aspect of the present invention relates to a process of preparing an aluminum alloy composition comprising the following steps:
(a) solutionizing heat treatment of a commercial grade aluminum alloy at a predetermined temperature and time; and
(b) quenching the heat-treated alloy at a predetermined cooling rate to produce the aluminum alloy composition,
wherein the solutionizing heat treatment includes soaking the material at a predetermined temperature to dissolve the iron (Fe) and silicon (Si) based particles of the aluminum alloy.
[029] In an embodiment, the soaking is done in a solid solution.
[030] In an embodiment, the solid solution is a single-phase alloy where alloying elements are dissolved in the aluminium matrix. After soaking the material is cooled rapidly to keep the alloying elements in supersaturated solid solution. Hence cooling rate is very critical.
[031] In an embodiment, the predetermined temperature is between 500 to 650 oC, preferably between 520 to 625 oC, more preferably between 580 to 620 oC.
[032] In an embodiment, the predetermined time for soaking is between 150 to 600 minutes, preferably between 180 to 500 minutes, more preferably between 180 to 400 minutes.
[033] In an embodiment, the predetermined cooling rate is between 2 to 2000 oC per sec, preferably between 100 to 1000 oC per sec.
[034] In an embodiment, the quenching is done using water, liquid nitrogen, dry ice, ice water or air, preferably the quenching is done in water or air at room temperature.
[035] The commercial aluminum alloy before heat treatment have iron (Fe) and silicon (Si) containing particles in the aluminum alloy matrix. The solutionizing heat treatment step done according to the described process dissolve iron (Fe) and silicon (Si) based particles into the solution and decrease the particle size distribution (% area fraction of particles) in aluminum alloy matrix. The solutionizing heat treatment includes soaking the material at a predetermined temperature which is high enough to dissolve the iron (Fe) and silicon (Si) based particles and rapidly cooling it in air or water to retain the microstructure.
[036] In an embodiment, the particle size distribution (% area fraction of particles) of the aluminum alloy prepared by the process described above reduces from 0.1% before solutionizing heat treatment to less than 0.02%, preferably less than 0.01% after the solutionizing heat treatment. Thus, providing aluminum alloy composition having zero or negligible precipitated particles in aluminum matrix thereby resulting in improved corrosion resistance properties which contributes towards higher energy utilization for aluminum air battery application.
[037] In addition to the reduction in precipitation of particles, the process overcomes the requirement of very low amount (< 50 ppm) of iron (Fe) and silicon (Si) in the aluminum alloy anode. Further, overcoming the use of expensive corrosion controlling elements such as gallium (Ga), indium (In), tin (Sn) or zinc (Zn) for improving corrosion resistance.
[038] Another aspect of the present invention relates to a method of preparing aluminum alloy anode comprising the following steps:
(a) aluminum billets of suitable size are cast by adding charge after calculation as per the requirement in a furnace,
(b) adding alloying elements after the aluminum charge is completely melted,
(c) casting the aluminum alloy melt into molds followed by manufacturing of aluminum alloy flat profiles of predetermined sizes,
(d) solutionizing heat treatment of the aluminum alloy flat profiles at a predetermined temperature and time,
(e) quenching the heat-treated aluminum alloy flat profiles at a predetermined cooling rate to produce the aluminum alloy anode.
[039] In an embodiment, the method of preparing aluminum alloy anode comprising the following steps:
(a) aluminum billets of suitable size are cast by adding charge after calculation as per the requirement in a furnace,
(b) adding alloying elements after the aluminum charge is completely melted,
(c) casting the aluminum alloy melt into book molds or billet molds of diameter between 6 inch to 12 inch followed by manufacturing of aluminum alloy flat profiles of predetermined sizes by machining, extrusion, or rolling, cutting and machining,
(d) solutionizing heat treatment of the aluminum alloy flat profiles at a predetermined temperature and time,
(e) quenching the heat-treated aluminum alloy flat profiles at a predetermined cooling rate to produce the aluminum alloy anode.
[040] In an embodiment, the furnace is selected from an induction furnace.
[041] In an embodiment, the alloying element added to the aluminum charge is 0.5 to 3% wt/wt, preferably 1.9 to 2.6% wt/wt of magnesium (Mg).
[042] In an embodiment, the manufacturing of aluminum alloy flat profiles is achieved through machining, extrusion or rolling and cutting.
[043] In an embodiment, the predetermined temperature in step (d) is between 500 to 650 oC, preferably between 520 to 625 oC, more preferably between 580 to 620 oC.
[044] In an embodiment, the predetermined time in step (d) is between 150 to 720 minutes, preferably between 300 to 720 minutes, more preferably between 400 to 600 minutes.
[045] In an embodiment, the predetermined cooling rate in step (e) is between 2 to 2000 oC per sec, preferably between 100 to 1000 oC per sec.
[046] In an embodiment, the aluminum alloy anode comprises Aluminum alloy flat profiles having thickness within 5mm to 25mm, preferably within 5mm to 15 mm.
[047] In an embodiment, the aluminum alloy anode comprises Aluminum alloy flat profiles having microstructure properties in terms Particle Size Distribution (%Area fraction) to be less than 0.02 %, preferably less than 0.01% after the solutionizing heat treatment. Thus, providing aluminum alloy anode having zero or negligible precipitated particles in aluminum matrix thereby resulting in improved corrosion resistance properties which contributes towards higher energy utilization for aluminum air battery application.
[048] The aluminum alloy anode generates high energy density when used as anode for aluminum-air battery. The high energy density achieved is greater than 4000 Wh/Kg, preferably 4.3KWh/kg.
[049] Another aspect of the present invention relates to an aluminum-air battery comprising: a cathode, an aluminum alloy anode according to present invention, and an electrolyte.
[050] In an embodiment, the aluminum-air battery comprises any standard aluminum air battery electrolyte known in the art, preferably selected from potassium hydroxide, sodium hydroxide or sodium chloride etc.
[051] In an embodiment, the aluminum-air battery comprises a cathode based on any commercially available aluminum-air battery cathode.
[052] The cost-efficiency of the aluminum alloy composition and the aluminum alloy anode prepared therefrom enhances the utility of commercial grade aluminum alloy, offering a cost-effective solution without compromising on performance or longevity. In essence, the aluminum alloy composition of the present invention and the aluminum anode prepared therefrom not only meets but exceeds the stringent demands of aluminum-air battery, addressing key aspects such as product quality, purity, equipment longevity, and economic viability.

EXAMPLES
[053] The following experimental examples are illustrative of the invention but not limitative of the scope thereof:
Example 1
[054] Magnesium containing P0202 grade aluminum alloy was subject to heat treatment between 520 to 625 oC followed by quenching the alloy in water at a cooling rate of 2 to 2000 oC per sec to achieve the inventive aluminum alloy microstructural characteristics. The compositions of the conventional grade aluminum alloy used for air battery application and inventive aluminum alloy compositions HILBP0204 and HILBP0205 prepared according to the process is as follows:
Component Conventional aluminum alloy (wt.%) HILBP0204 (wt.%) HILBP0205
(wt.%)
Silicon 0.0062 0.0092 0.0142
Iron 0.00547 0.0129 0.0164
Manganese 0.0010 0.0004 0.0004
Magnesium 2.59 2.08 2.48
Copper 0.0038 0.0005 0.00017
Zinc 0.000757 0.0012 0.0010
Chromium 0.0 0.0 0.0
Titanium 0.000219 0.000886 0.0012
Others 0.0 0.0 0.0
Aluminum Remaining Remaining Remaining
[055] The Particle Size Distribution (%Area fraction) of commercial grade aluminum alloy, HILBP0204 and HILBP0205 are compared and shown in Figure 1. The total Particle Size Distribution (%Area fraction) of particles shows reduction from 0.05% to 0.02% for HILBP0204 and reduction from 0.06% to 0% for HILBP0205 as compared to the Particle Size Distribution (%Area fraction) of the respective as cast material.
[056] SEM images of Particle Size Distribution (%Area fraction) before and after heat treatment is shown in Figure 2 (a) and (b). The images correspond to cast stage and heat-treated stage samples of HILBP0204 having base composition of commercial aluminum with alloying of Magnesium.
[057] Comparison of energy utilization of commercial grade aluminum conventional alloy, HILBP0204 and HILBP0205 are shown in Figure 3. The inventive aluminum alloy compositions HILBP0204 and HILBP0205 demonstrated an increase in energy density from 4.0KWh/kg to 4.3KWh/kg in comparison to the conventional grade aluminum alloy.

Example 2
[058] Billets of metal alloy (P0202 purity Aluminum) were cast by adding charge after calculation as per the requirement in induction furnace. Alloying (0.5 to 3% wt/wt Mg) addition is done as per the charge calculation after metal charge is completely melted. The melt is cast into billet molds of 7 inch followed by machining of the billets to 6 inch. These billets were then extruded into flats of 120 x 10 mm in an extrusion press at plant scale. Extruded flats were cut in sizes necessary (205 mm length) for further solution heat treatment (heating at 580 to 620 oC for 8 to 10 hrs followed by quenching with water). After heat treatment, flats were machined to the desired sizes (205 x 111 x 10 mm) followed by surface buffing. The results of Particle Size Distribution (%Area fraction) are shown below and in Figure 4 (a) and (b) and Figure 5 (a) and (b):
Particle Size Distribution (%Area fraction)
Sample ID PSD Before Heat treatment PSD After Heat Treatment
BC7 0.12% 0.02%
BC8 0.12% 0.01%

[059] Chemical composition of the samples BC7 and BC8 is as follows:
Sample ID PPM
B Cu Fe Mg Mn Zn Ti V Si Ga
(BC7) 4.3 2.1 106 19300 3.4 12 8.1 13.7 201 49
(BC8) 57 2.8 115 18500 3.8 16 8.4 13.7 156 47

[060] Advantageously, the aluminum alloy composition disclosed in the present invention provides a range of key benefits, particularly for advanced energy storage and conversion applications, such as aluminum-air batteries. One of the primary advantages is its ability to significantly reduce corrosion rates. This reduction not only enhances the longevity and efficiency of metal-air batteries but also improves the overall energy utilization and performance of the system, ensuring that the battery operates for extended periods with minimal degradation. By addressing the challenges associated with high corrosion rates, the composition contributes to the operational longevity of energy storage systems, making them more reliable and effective.
[061] Another key advantage is the cost-effectiveness of the composition. Unlike traditional alloys that require exotic or expensive alloying elements, such as gallium, indium, or zinc, for corrosion control, the present invention utilizes commercially available aluminum alloys with carefully controlled amounts of common elements like magnesium, silicon, and iron. This makes the composition more accessible and cost-efficient, offering a solution that is not only high-performing but also economically viable. This eliminates the need for specialized, high-purity materials, making it an attractive option for large-scale applications where cost efficiency is a critical factor.
[062] Moreover, the alloy’s microstructural stability plays a crucial role in its enhanced properties. Through the heat treatment process, including solutionizing and quenching, the alloy experiences a significant reduction in the percentage of precipitated particles, which are often responsible for accelerating corrosion. This refinement of the microstructure contributes to better corrosion resistance and higher energy density, as the particles that could otherwise interfere with the battery’s performance are minimized. As a result, the energy density of the alloy increases, making it ideal for use as an anode in aluminum-air batteries, where higher energy density is crucial for maximizing battery performance.
[063] The precise control of alloying elements, particularly magnesium, within an optimal range, enhances corrosion resistance of the alloy. This careful tuning ensures that the alloy can withstand the demanding conditions of energy storage applications while maintaining long-term durability. Additionally, the low content of iron and silicon in the alloy reduces the formation of detrimental phases that could otherwise compromise its performance, resulting in a higher level of purity and stability.
[064] Overall, the aluminum alloy composition disclosed in this invention offers an optimal balance of cost, performance, and sustainability. It provides a corrosion-resistant material that improves the efficiency and operational lifespan of energy storage systems, while simultaneously reducing the need for expensive, specialized materials. These advantages make it a highly attractive option for advancing the development of efficient, cost-effective, and long-lasting energy storage solutions.
[065] The foregoing description of the invention has been set merely to illustrate the invention and is not intended to be limiting. Since the modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to the person skilled in the art, the invention should be construed to include everything within the scope of the disclosure. ,CLAIMS:We Claim:
1. An aluminum alloy composition comprising:
- 0.005 to 0.1 %wt/wt of silicon (Si)
- 0.005 to 0.1 %wt/wt of iron (Fe)
- 0 to 0.1 %wt/wt of manganese (Mn)
- 0.5 to 6.0 %wt/wt of magnesium (Mg)
- 0 to 0.1 %wt/wt of copper (Cu)
- 0 to 0.1 %wt/wt of zinc (Zn)
- 0 to 0.1 %wt/wt of chromium (Cr)
- 0 to 0.1 %wt/wt of titanium (Ti)
- 0 to 0.05 %wt/wt others; and the balance is aluminum (Al).
2. The aluminum alloy composition as claimed in claim 1, comprising:
- 0.005 to 0.03 %wt/wt of silicon (Si)
- 0.005 to 0.03 %wt/wt of iron (Fe)
- 0 to 0.01 %wt/wt of manganese (Mn)
- 0.5 to 3.0 %wt/wt of magnesium (Mg)
- 0 to 0.01 %wt/wt of copper (Cu)
- 0 to 0.01 %wt/wt of zinc (Zn)
- 0 to 0.01 %wt/wt of chromium (Cr)
- 0 to 0.01 %wt/wt of titanium (Ti)
- 0 to 0.05 %wt/wt others; and the balance is aluminum (Al).
3. A process of preparing an aluminum alloy composition comprising the following steps:
(a) solutionizing heat treatment of a commercial grade aluminum alloy at a predetermined temperature and time; and
(b) quenching the heat-treated alloy at a predetermined cooling rate to produce the aluminum alloy composition,
wherein the solutionizing heat treatment includes soaking the material at a predetermined temperature to dissolve the iron (Fe) and silicon (Si) based particles of the aluminum alloy.
4. The process as claimed in claim 3, wherein the soaking is done in a solid solution.
5. The process as claimed in claim 3, wherein the predetermined temperature is between 500 to 650 oC, preferably between 520 to 625 oC, more preferably between 580 to 620 oC.
6. The process as claimed in claim 3, wherein the predetermined time is between 150 to 720 minutes, preferably between 300 to 720 minutes, more preferably between 400 to 600 minutes.
7. The process as claimed in claim 3, wherein the predetermined cooling rate is between 2 to 2000 oC per sec, preferably between 100 to 1000 oC per sec.
8. The process as claimed in claim 3, wherein the quenching is done using water, liquid nitrogen, dry ice, ice water or air, preferably the quenching is done in water or air at room temperature.
9. A method of preparing aluminum alloy anode comprising the following steps:
(a) aluminum billets of suitable size are cast by adding charge after calculation as per the requirement in a furnace,
(b) adding alloying elements after the aluminum charge is completely melted,
(c) casting the aluminum alloy melt into molds followed by manufacturing of aluminum alloy flat profiles of predetermined sizes,
(d) solutionizing heat treatment of the aluminum alloy flat profiles at a predetermined temperature,
(e) quenching the heat-treated aluminum alloy flat profiles at a predetermined cooling rate and time to produce the aluminum alloy anode.
10. The method as claimed in claim 9, wherein the furnace is selected from an induction furnace.
11. The method as claimed in claim 9, wherein the alloying element added to the aluminum charge is 0.5 to 3% wt/wt of magnesium (Mg), preferably 1.9 to 2.6% wt/wt of magnesium (Mg).
12. The method as claimed in claim 9, wherein the manufacturing of Aluminum alloy flat profiles is achieved through machining, extrusion or rolling and cutting.
13. An aluminum alloy anode, wherein the aluminum alloy anode comprises aluminum alloy flat profiles having aluminum alloy composition as claimed in claims 1 and 2 and having Particle Size Distribution (%Area fraction) less than 0.02 %, preferably less than 0.01%.
14. The aluminum alloy anode as claimed in claim 13, wherein the aluminum alloy flat profiles have thickness within 5 to 25mm, preferably within 5 to 15 mm.
15. An aluminum-air battery comprising
- a cathode
- an aluminum alloy anode as claimed in claims 13 to 14, and
- an electrolyte

Dated this 29th of January 2024

Hindalco Industries Limited,
Aditya Birla Science and Technology Company Pvt. Ltd, and
Phinergy Ltd.
By their Agent & Attorney

(Nisha Austine)
of Khaitan & Co
Reg No IN/PA-1390