Fuel-Rechargeable Battery Systems, Devices, and Components

Abstract

A metal-air battery comprising: a current collector; a metal electrode containing a metal and in contact with the current collector; an air electrode on the metal electrode and on the opposite side of the current collector; a solid electrolyte between the metal electrode and the air electrode; and a discharge product of the metal on the air electrode, wherein the metal-air battery is configured to release the discharge product.

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims the benefit of priority from U.S. Provisional Patent Application No. 63 / 392,749, filed Jul. 27, 2022; U.S. Provisional Patent Application No. 63 / 375,278, filed Sep. 12, 2022; U.S. Provisional Patent Application No. 63 / 414,805, filed Oct. 10, 2022; and U.S. Provisional Patent Application No. 63 / 489,887, filed Mar. 13, 2023, all of which are hereby incorporated by reference in their entirety for all purposes under 35 U.S.C. § 119.

Background Art

[0002] Batteries having high energy density or low cost are often non - rechargeable, have limited rechargeability, or have insufficient specific energy. Thus, for practical use, there is still a need for improved batteries or battery systems having an improved combination of energy density, specific energy, cost, and rechargeability.

Summary of the Invention

[0003] A metal - air battery is disclosed that includes a current collector; a metal electrode containing a metal and in contact with the current collector; an air electrode on the metal electrode and on the opposite side of the current collector; a solid electrolyte between the metal electrode and the air electrode; and a discharge product of the metal on the air electrode, and the metal - air battery is configured to liberate the discharge product.

[0004] An electric aircraft system is disclosed that includes an electric aircraft and a metal - air battery, the metal - air battery including a current collector; a metal electrode containing an alkali metal and in contact with the current collector; an air electrode on the metal electrode and on the opposite side of the current collector; and a solid electrolyte between the metal electrode and the air electrode, the metal - air battery being configured to liberate a discharge product, and the electric aircraft being configured to discharge the discharge product.

[0005] A method for converting a discharge product of a metal-air battery into a metal is disclosed, the method comprising: providing a discharge product of a metal-air battery; contacting the discharge product with a liquid to form a brine; disposing the brine in an electrolytic cell containing a solid electrolyte; and electroplating the metal from the brine to convert the metal-air battery discharge product into a metal.

[0006] A method for collecting a discharge product of a metal-air battery is disclosed, the method comprising: providing a metal-air battery configured to liberate a discharge product; flushing the air electrode of the metal-air battery with a gas stream to remove the discharge product from the air electrode and provide a gas stream incorporating the discharge product, or flushing the air electrode of the metal-air battery with a liquid to remove the discharge product from the air electrode and provide a solution containing the discharge product, to collect the discharge product.

[0007] A method for processing a discharge product of a metal-air battery is disclosed, the method comprising: providing a discharge product from a metal-air battery; contacting the collected discharge product with water to form a brine containing metal ions of the metal of the metal-air battery; disposing the brine in an electroplating cell in contact with an electrolyte conductive to the metal ions; and reducing the metal ions on a current collector to form the metal of the metal-air battery to process the discharge product.

[0008] A method for manufacturing a metal-air battery is disclosed, the method comprising: collecting a discharge product from a metal-air battery; contacting the collected discharge product with water to form a brine containing metal ions of the metal of the metal-air battery; disposing the brine in an electroplating cell in contact with an electrolyte conductive to the metal ions; reducing the metal ions on a current collector to form the metal of the metal-air battery on the current collector; and disposing an air electrode on the electrolyte to manufacture the metal-air battery, wherein the collecting comprises the method for collecting a discharge product of the metal-air battery as described above.

[0009] A method for manufacturing a battery is disclosed, the method including collecting discharge products from a metal-air battery; contacting the collected discharge products with water to form a brine containing metal ions of the metal of the battery; disposing the brine in an electrodeposition cell in contact with a conductive electrolyte; reducing the metal ions on a current collector to form the metal of the battery on the current collector; and disposing an electrode containing an intercalation compound on the electrolyte to manufacture the battery.

[0010] A method for manufacturing a metal-air battery is disclosed, the method including providing a current collector; disposing a precursor of a solid electrolyte on the current collector; treating the precursor to form the solid electrolyte; contacting the solid electrolyte with a liquid containing metal ions of the metal of the metal-air battery; reducing the metal ions to electrodeposit the metal on the current collector; and disposing an air electrode on the electrolyte to manufacture the metal-air battery.

[0011] A method for manufacturing a metal-air battery is disclosed, the method including providing a current collector; disposing a solid electrolyte on the current collector; irradiating the solid electrolyte to densify the solid electrolyte; contacting the solid electrolyte with a liquid containing metal ions of the metal of the metal-air battery; reducing the metal ions to electrodeposit the metal on the current collector; and disposing an air electrode on the electrolyte to manufacture the metal-air battery.

[0012] An electric vehicle including the above metal-air battery is disclosed.

[0013] A method for carbon sequestration is disclosed, the method including operating the above electric vehicle; forming discharge products by contacting the air electrode with air containing carbon dioxide, the discharge products containing carbonates, bicarbonates, or combinations thereof; and releasing the discharge products to sequester the carbon.

[0014] A system is disclosed that includes an electrolytic cell for electrochemically producing a metal and a metal-air battery that includes the metal. The system includes a metal-air battery that includes a current collector, a metal electrode that includes the metal and is in contact with the current collector, an air electrode on the metal electrode, and a first solid electrolyte between the metal electrode and the air electrode; and an electrolytic cell that includes a brine container configured to contain a brine that includes metal ions of the metal, a second solid electrolyte between the brine container and the metal electrode of the metal-air battery, a cathode of the electrolytic cell on a side of the second solid electrolyte opposite the brine container, and an anode of the electrolytic cell that is in contact within the brine and on a side of the second solid electrolyte opposite the brine container.

[0015] A method for electrochemically producing a metal and for using the metal within a metal-air battery is disclosed. The method includes providing a system that includes a metal-air battery that includes a current collector, a metal electrode that includes the metal and is in contact with the current collector, an air electrode on the metal electrode, and a first solid electrolyte between the metal electrode and the air electrode; and an electrolytic cell that includes a brine contained within a brine container that includes metal ions of the metal, a second solid electrolyte between the brine and the metal electrode of the metal-air battery, a cathode of the electrolytic cell on a side of the second solid electrolyte opposite the brine container, and an anode of the electrolytic cell that is in contact within the brine and on a side of the second solid electrolyte opposite the brine container; providing a voltage between the cathode of the electrolytic cell and the anode of the electrolytic cell to transport metal ions from the brine to form the metal of the metal ions on the cathode of the electrolytic cell; and contacting the air electrode with air to convert the metal on the cathode and within the air battery to discharge products to use the metal.

[0016] A method of charging a metal-air battery is disclosed, the method comprising providing a metal-air battery including a solid electrolyte between an air electrode and a metal electrode and a protective fluid on the metal electrode on the opposite side of the solid electrolyte, the protective fluid and the metal electrode being contained within a container having an upper inlet and a lower inlet; and adding the metal through at least one of the upper inlet or the lower inlet to charge the metal-air battery.

[0017] A method of operating a metal-air battery is disclosed, the method comprising providing a metal-air battery including a solid electrolyte between an air electrode and a metal electrode and a protective fluid on the metal electrode on the opposite side of the solid electrolyte, the protective fluid and the metal electrode being contained within a container having an upper inlet and a lower inlet; and heating the metal to float the metal on the protective fluid or cooling the metal to deposit the metal in the protective fluid to operate the metal-air battery.

[0018] A system configured to thermochemically produce a metal is disclosed, the system including a metal salt including a discharge product of a metal-air battery and a container configured to control pressure, temperature, atmosphere, or a combination thereof, the container including an inlet, an outlet, or both.

[0019] A method of thermochemically producing a metal is disclosed, the method comprising providing a metal salt; providing a container configured to control pressure, temperature, atmosphere, or a combination thereof, the container including an inlet, an outlet, or both; disposing the metal salt within the container; and controlling the pressure, the temperature, the atmosphere, or a combination thereof to thermochemically decompose the metal salt to produce the metal.

[0020] The foregoing and other features are illustrated by the following figures and detailed description.

[0021] The following figures are exemplary embodiments in which similar elements are similarly numbered.

Brief Description of the Drawings

[0022]

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DETAILED DESCRIPTION OF THE INVENTION

[0023] Batteries with high energy density or low cost are often non-rechargeable or have limited rechargeability, and often only a portion of the total battery capacity or state of charge can be efficiently refilled, or they have a short cycle life when recharged. Examples of high energy density batteries that are inadequately rechargeable include metal-air batteries such as lithium-air (Li-air), sodium-air (Na-air), aluminum-air (Al-air), silicon-air (Si-air) batteries, or lithium-carbon fluoride (Li-CF x ) batteries. Rechargeable lithium-air batteries have been widely studied but are not currently used in a wide range of applications. This is partly because realizing rechargeability requires expensive components and a more complex battery design, and the addition of components that enable rechargeability (e.g., battery enclosure and purification of the air stream to enable a supply of clean oxygen) significantly offsets the advantages of the energy density or specific energy that Li-air can provide. Thus, the potential for achieving improved energy density or specific energy has increased interest in air batteries, but inadequate rechargeability, as well as the complexity and cost of providing rechargeability, have limited the practicality of such batteries.

[0024] To address the foregoing challenges, systems, devices, components, materials, methods of use, and methods of manufacture are disclosed for a battery that is at least partially rechargeable or refueled by replacement of a negative or positive electrode-active material, or both. In particular, systems and methods are disclosed that enable the use of battery electrochemistry that have attractive features such as high energy density, high specific energy, or low cost, and heretofore have been considered non-rechargeable or have insufficient rechargeability for applications that have required rechargeable batteries. Systems and methods are disclosed that enable rapid recharge of a device or system powered by a battery. Thus, recharge or refueling may be performed by removing and replacing the battery from the device or system powered by the battery, e.g., replacing a at least partially discharged battery with a charged battery. Systems and methods are disclosed for collecting, purifying, restoring, or processing discharge products of a battery, which may be valuable, and returning the products for use in other applications, including battery applications similar to those that generate the battery or discharge products. Systems and methods are disclosed for providing a power source that can operate as a fuel cell and can be supplied with a reactant, preferably an alkali metal, from which discharge products are continuously removed. Systems and methods are disclosed for using discharge products of a battery for carbon dioxide recovery or sequestration, or for deacidification, i.e., increasing the pH, of a water stream or aqueous body, including natural waters such as oceans, bays, or seas. In particular, rechargeable or refillable metal-air batteries are disclosed. In one aspect, the metal-air battery is designed to allow removal of discharge products. In one aspect, the metal-air battery is designed to collect discharge products of the metal-air battery. In one aspect, the discharge products are processed for reuse. In one aspect, a device or system includes a metal-air battery. In one aspect, a charged metal-air battery is provided to the device or system.

[0025] Here, the "metal-air" battery is understood to include, without limitation, any suitable chemical species that can be oxidized at the battery's electrode when the battery is discharged, such as alkali metals, alkaline earth metals, metal alloys, metalloids such as Si or Ge, sulfur, boron, or phosphorus, as "metal". At the counter electrode of the battery, when the battery is discharged, oxygen molecules are reduced. Other variants of the metal-air battery include batteries in which the chemical species reduced at the air electrode (e.g., gas electrode) includes molecular species other than oxygen, and batteries that can be supplied to the gas electrode as a gas or as a molecular species dissolved in a liquid, including, without limitation, carbon dioxide, carbon monoxide, nitrogen, nitrogen oxide, or sulfur oxide. As used herein, the term "air" refers to any suitable gas for use as an electrode active material within the metal-air battery and may include oxygen, carbon dioxide, carbon monoxide, or air.

[0026] The battery may provide power for a vehicle, which can be a ground vehicle, an aircraft, or a water vehicle. In one aspect, the battery includes at least a part of a propulsion system for an electric aircraft, including, without limitation, drones, vertical takeoff and landing aircraft (VTOL), passenger aircraft, fixed-wing passenger aircraft, and hybrids thereof. In one aspect, the battery includes at least a part of a propulsion system for an automobile, a bus, a truck, or a locomotive. The battery may also include at least a part of a propulsion system for a boat or a ship. The battery may also provide stationary storage of electricity from any suitable source of power generation, including renewable sources of power generation such as wind or solar generators, for use by stationary electrical consumers, including residential, commercial, or utility consumers. The energy stored in such stationary batteries may vary in scale from kilowatt-hours to gigawatt-hours. The battery may provide emergency backup power as a stationary or portable facility, for example, in the event of a war or natural disaster that causes a loss of electrical supply.

[0027] The disclosed systems include a power system including a battery that is electrically discharged or partially discharged during use, a system for recycling or reconstructing the battery to restore the battery to a charged state, and a system for providing the charged battery to the power system again.

[0028] In one aspect, the battery is a primary battery, whereby it is understood that the battery is electrically discharged and not recharged. In one aspect, the battery is a secondary or rechargeable battery and is electrically discharged and recharged 5 times or less, and each recharge includes a stored electrical quantity (e.g., in kilowatt-hours) equal to the initial or nameplate capacity of the battery before the battery is recycled or reconstructed.

[0029] The discharged battery may be recycled or reconstructed by removing the battery from the power system, recycling one or more of the electrodes of the battery, and supplying the newly constructed or reconstructed battery to the power system. Thus, at least a portion of the materials in the discharged battery are reused for the same purpose, whether or not materials from the discharged battery from which the newly constructed or reconstructed battery is replaced are directly used, to achieve "circularity" of the materials. In one aspect, the materials of the discharged battery are taken and used for other purposes, such as for the manufacture of different types of batteries.

[0030] Electrochemical systems, battery types and compositions, and methods for recycling and reconstructing batteries are described herein.

[0031] (1) Battery A metal-air battery has a metal electrode, an air electrode, and an electrolyte that provides ion communication between the metal and the air electrode. The metal electrode functions as the negative electrode of the battery cell, and the air electrode functions as the positive electrode. As shown in FIG. 1A, in a metal-air battery where the metal is an alkali metal such as lithium or sodium, the ions acting are lithium or sodium cations transported between the metal and the air electrode. In further detail, as shown in FIG. 1A, the metal-air battery 100 includes a metal electrode 110, an electrolyte 120, and an air electrode 130 on the opposite side of the metal electrode. The acting ions Li + or Na + are transported in the electrolyte, and the discharge product 140 is formed on the outer surface of the air electrode on the opposite side of the electrolyte. Alternatively, the acting ions may be anions as shown in FIG. 1B. As shown in FIG. 1B, the metal-air battery 150 includes a metal electrode 160, an electrolyte 170, and an air electrode 180 on the opposite side of the metal electrode. The acting ions OH - are transported in the electrolyte, and the discharge product 190 is formed on the surface of the metal electrode and in the electrolyte. Examples include Zn-air or Fe-air batteries.

[0032] In one aspect, the metal-air battery includes a configuration that provides for the removal of discharge products. The discharge products may be formed at the air electrode. The air electrode (i.e., the gas diffusion electrode) may include a gas diffusion electrode material, and the discharge products may be formed on the gas diffusion electrode material. In one aspect, the discharge products may be formed on the surface of the gas diffusion electrode material, on the outer surface of the gas diffusion electrode material, or inside the gas diffusion electrode material. The gas diffusion electrode may include an active layer that may include a catalyst, a supported catalyst, and a binder. In one embodiment, the active layer may be used to create a potential difference between the positive and negative electrodes when the cell is connected to a load. Thus, the gas diffusion electrode is positioned within the cell housing such that the active layer (and the active materials within) faces the cell chamber and contacts the ion conductive medium, whereby ions may be conducted through the ion conductive medium to and / or from the metal negative electrode. In some embodiments, the active materials of the active layer may be formed by, sintered, layered, or otherwise combined by a mixture of catalyst particles or materials, a conductive matrix, and a hydrophobic material to form a composite material. In various embodiments, the active layer may be of any suitable construction or configuration including, but not limited to, carbon; fluoropolymers such as polytetrafluoroethylene (PTFE), perfluoroalkoxy alkane (PFA), fluorinated ethylene propylene (FEP), and / or polyvinylidene fluoride (PVDF); epoxies; conductive particles such as graphite, nickel, activated carbon, carbon fibers, carbon nanotubes, or graphene; fibers such as PTFE, polypropylene (PP), polyethylene (PE), SiO2, or Al2O3; or any other suitable metal or alloy. In some embodiments, the active layer contains a catalyst for promoting the reduction of oxygen.This catalyst can be incorporated as independent particles or supported on other common catalysts such as conductive substrates like carbon black, activated carbon or graphite, or platinum, platinum alloys, silver, silver alloys, manganese oxide, nickel, Raney nickel, nickel oxide, nickel hydroxide, nickel oxyhydroxide, cobalt oxide, perovskite, spinel, metal-nitrogen-carbon frameworks, heteroatom-doped carbon, heteroatom-doped carbon fibers, heteroatom-doped carbon nanotubes, or heteroatom-doped graphene.

[0033] In various embodiments, the barrier layer functions as a backing material for the active layer. The barrier layer facilitates gas transport from the gas flow channel to the catalyst surface. The barrier layer may vary depending on the embodiment, but in some embodiments, the barrier layer may include a fluoropolymer. As an example, in various embodiments, the barrier layer may include PTFE, which may be thermomechanically expanded in some embodiments (also known as ePTFE or Gore-Tex®). In other embodiments, the barrier layer may include FEP or any other fluoropolymer. The barrier layer may be composed of other binders such as polypropylene, polyethylene, polyamide, or epoxy. In some embodiments, the barrier layer may contain other materials including, but not limited to, carbon, graphite, nickel, steel, alumina, titania to increase conductivity and / or structural strength.

[0034] When the cell is in the discharge mode, a current collector configured to receive electrons from a load for consumption by an oxygen reduction reaction may be electrically connected to the active layer or the barrier layer. The current collector may be of any suitable construction or configuration, such as, but not limited to, a screen or a flow field. A metal screen current collector may be in the range of about 50 to 2500 μm as conventional, but preferably in the range of 100 to 1000 μm, and may be recognized as having holes therein that can be uniformly dispersed throughout the area in some embodiments. In various embodiments, the current collector may be constructed of, but not limited to, nickel, or nickel alloys such as nickel cobalt, nickel iron, nickel copper (i.e., Monel), or superalloys, copper or copper alloys, aluminum or aluminum alloys, titanium or titanium alloys, brass, bronze, carbon, graphite, platinum, silver, silver - palladium, carbon steel, stainless steel, or any other suitable metal or alloy, plating or clad metal (i.e., nickel plated copper or other such combinations of base metal and plating or clad metal).

[0035] In some embodiments, the electrolyte is a solid electrolyte, and any one or more of the active layer, the current collector, or the barrier layer may be attached or bonded to the solid electrolyte. In certain embodiments, the active layer may be electrically continuous and also function as a current collector. Such an active layer may be porous or may be a substantially dense layer.

[0036] The metal - air battery may be a lithium - air, sodium - air, potassium - air, calcium - air, magnesium - air, aluminum - air, zinc - air, iron - air, or silicon - air battery. In some embodiments, a Li - air battery or a Na - air battery is particularly preferred.

[0037] In one aspect, the electrolyte contains ions that act in the metal - air battery, and the acting ions may correspond to the metal of the negative electrode of the metal - air battery and may be contained in the electrolyte of the metal - air battery. For example, the acting ions are Li + 、Na+ , K + , or Ca 2+ may also be used.

[0038] (2) Removal of Discharge Products Discharge of a metal-air battery results in oxidation of the metal at the negative electrode and formation of one or more discharge products. As used herein, "discharge products" may be singular or plural. In one aspect, the metal at the negative electrode may be an alkali metal such as lithium or sodium, and the discharge products are oxidation products of the metal. The discharge products may be metal hydroxides, oxides, peroxides, carbonates, bicarbonates, oxalates, peroxyoxylates, halides, or combinations thereof. In one aspect, examples of discharge products of non-aqueous Li-air or Na-air batteries include, for example, LiO2, Li2O2, Li2O, NaO2, Na2O2 or Na2O, or combinations thereof. Other gaseous reactants may also be used separately from oxygen. For example, a Li-CO2 battery may form lithium bicarbonate LiHCO3 or lithium carbonate Li2CO3 as discharge products at the gas electrode, and a Na-CO2 battery may form sodium bicarbonate NaHCO3 or sodium carbonate Na2CO3 as discharge products at the gas electrode. Other discharge products include metal oxalates such as Li2C2O4 or Na2C2O4, or metal peroxyoxalates or diperoxocarbonates such as Li2C2O6 or Na2C2O6. In aqueous or non-aqueous-aqueous hybrid Li-air batteries, the discharge products may be LiOH or its hydrate at least partially dissolved in the aqueous electrolyte in contact with the air cathode. In contrast, in the case of Zn-air and Fe-air, the electrolyte may be an alkaline solution, and during discharge, oxygen is reduced at the air cathode to form OH - ions, which may react with the metal to form highly soluble Zn(OH)4 or largely insoluble Fe(OH)2 in the electrolyte. In these examples, the discharge products are formed at or near the metal electrode when the metal electrode undergoes oxidation.

[0039] The discharge product may be soluble in a liquid. The liquid may be aqueous or non-aqueous. In one aspect, the discharge product may be soluble in water, the liquid may contain water, and may be an aqueous solution. In some embodiments, the discharge product may be soluble in a non-aqueous solvent such as a C1-C4 carbonate, a C1-C4 alcohol, a C1-C4 ketone, or a combination thereof, and may form a non-aqueous solution in the non-aqueous solvent. The discharge product may be soluble in an ionic liquid. For example, the discharge product of a lithium-air battery may be lithium fluoride, and the ionic liquid may be an aluminum-alkali metal chloride such as an ionic liquid having a melting point of less than 100 °C, such as 10 °C - 200 °C or 20 °C - 150 °C, for example, a chloroaluminate ionic liquid.

[0040] In one aspect, the discharge product may be formed at the negative electrode and may be removed by forming a solution upon dissolution in a liquid, and the solution may be removed from the metal-air battery. A non-limiting example is a Zn-air battery, in which case the discharge product is zincate ions, such as ZnO2 2- is included. Zincate ions are soluble in an alkaline solution and may be dissolved to form an alkaline solution, and the solution containing zincate ions may be removed from the metal-air battery as described herein, for example, for disposal or for collection for later processing.

[0041] The metal-air battery may be configured to remove one or more discharge products from the negative electrode after discharge of the metal-air battery. In one aspect, the discharge products of the metal-air battery may be collected while the metal-air battery remains installed in a device or system that it powers.

[0042] In one aspect, the air electrode of a metal-air battery may be flushed with a fluid such as a gas stream to remove discharge products from the air electrode. The gas stream may include an inert gas that is substantially non-reactive or inert with respect to the discharge products. Representative inert gases include, but are not limited to, nitrogen, argon, helium, hydrogen, or combinations thereof. The gas stream may include a reactive gas that is reactive with the discharge products. Representative reactive gases include, but are not limited to, water (vapor), carbon monoxide, carbon dioxide, or combinations thereof. The gas stream may be a mixture of nitrogen and oxygen, or may include air.

[0043] The gas stream may be pump-injected or transported by natural convection such as thermal convection to create a gas flow. The temperature and composition of the gas stream may be selected to provide an appropriate removal rate of the discharge products from the metal-air battery. For example, the humidity, water vapor pressure, dew point, temperature, or combinations thereof of the air stream may be selected (increased or decreased) to select the rate at which discharge products, such as metal oxides, metal peroxides, or metal superoxides, are removed, or the rate at which the discharge products are contacted with a reactive gas to form and remove secondary products such as metal hydroxides. In some embodiments, the water vapor pressure may be between about 1.013 MPa (about 0.001 atm) and 101.3 kPa (1 atm). Similarly, the partial pressure of carbon dioxide and / or the temperature of the gas stream containing air may be selected to select the formation rate and the removal rate of the metal carbonate discharge products. In some embodiments, the partial pressure of carbon dioxide may be between about 0.0003 ppm and about 101.3 kPa (about 1 atm).

[0044] In one aspect, the air electrode may be flushed with a liquid to remove discharge products. The liquid may be aqueous or non-aqueous and may dissolve or suspend the discharge products to form a mixture, suspension, or solution. Representative aqueous liquids include water, and representative non-aqueous liquids include C1-C4 carbonates, C1-C4 alcohols, C1-C4 ketones, or combinations thereof. Optionally, the air electrode may be flushed with another fluid to further process the electrode. For example, the other fluid may be dry air, and the air electrode may be flushed with dry air to dry the air electrode.

[0045] The air electrode may be configured to provide an appropriate combination of gas or liquid flow rate, direction, and laminar and turbulent flow (i.e., Reynolds number). The air electrode may have any suitable configuration of channels, passages, venturis, constrictions, patterns, or combinations thereof to provide an appropriate velocity and direction of gas or liquid flow. In some embodiments, the gas flow rate may be between about 0.1 meters per second (m / s) and about 500 m / s. In some embodiments, the liquid flow rate may be between about 0.001 m / s and about 100 m / s. The air electrode may be wavy or have a flow field including channels, passages, and / or other patterns adjacent to the electrode to control the flow of gas or liquid during operation.

[0046] Removal of discharge products from a metal-air battery may be performed at any suitable state of charge of the battery. In one aspect, the discharge products may be removed when the metal-air battery is substantially (e.g., fully) discharged. In one aspect, the discharge products may be removed when the metal-air battery is partially discharged. FIG. 2A shows a metal-air battery 200 in an initial charged state having a current collector 205, a metal electrode 210, an electrolyte 220, and an air electrode (e.g., air cathode) 230. As shown in FIG. 2A, the discharge products may not be present. FIG. 2B shows the metal-air battery 200 after a first discharge and shows discharge products 240 formed on the air electrode. The content of the metal electrode 210 shown in FIG. 2B is less than the content of the metal electrode in the initial state shown in FIG. 2A because a portion of the metal has been converted to the discharge products 240. FIG. 2C shows the metal-air battery 200 after a second discharge and shows discharge products 240 formed on the air electrode. The content of the metal electrode 210 shown in FIG. 2C is less than the content of the metal electrode after the first discharge shown in FIG. 2B because more of the metal has been converted to the discharge products 240. FIG. 2D shows the metal-air battery 200 after a discharge state and shows discharge products 240 formed on the air electrode. The metal electrode 210 has been entirely converted to the discharge products 240.

[0047] As also shown in FIG. 2D, the discharge products may be removed after the first discharge, after the second discharge, after the last or full discharge, or combinations thereof. When the metal-air battery is fully discharged, the metal negative electrode and optionally other components may also be replaced before the metal-air battery is discharged again. The metal-air battery may be configured to undergo cycles of partial discharge and subsequent removal of the discharge products. The discharge products may be removed continuously or intermittently.

[0048] The advantage of having a configuration in which the discharge products can be removed continuously or intermittently enables an operating mode in which the power and capacity losses due to the accumulation of the discharge products can be reduced during the discharge cycle. Another advantage is that while obtaining a high discharge power by removing the discharge products, the metal electrodes or the entire metal-air battery can be replaced at less frequent intervals. In some embodiments, the process and removal rate of the discharge products may be selected to maintain the desired discharge power of the metal-air battery. For example, the convective removal of the discharge products may be carried out at a higher speed when a high discharge power is indicated, at a lower speed when a low discharge power is indicated, or not carried out at all.

[0049] (3) Collection of Discharge Products In one aspect, the discharge products of the metal-air battery may be collected by removing one or more components from the metal-air battery, collecting the discharge products from the components, and replacing one or more components within the battery. For example, the components to be removed may be the positive electrode, negative electrode, or both of the metal-air battery. As a specific non-limiting example, the air electrode of a Li-air or Na-air battery may be removed, the discharge products may be flushed to remove the discharge products from the air electrode, the air electrode may be returned to the component, and the metal-air battery may be returned to the place of business. As another example, the positive electrode of a Li-CF x battery may be removed after discharge, the LiF discharge products may be removed by dissolution in a suitable liquid, and the positive electrode may be replaced or returned to service. In one aspect, the suitable liquid may be any suitable liquid capable of dissolving the LiF discharge products, such as an aqueous hydrofluoric acid solution or a metal halide melt containing AlCl3. As another example, the metal electrode containing the discharge products may be removed from the metal-air battery, the discharge products may be removed by dissolving the discharge products in a suitable liquid, the metal electrode may be replaced within the metal-air battery, and the metal-air battery may be returned to service. In one aspect, the suitable liquid may be any suitable liquid capable of dissolving the discharge products.

[0050] (4) Processing of the discharge product In one aspect, the metal of the metal-air battery may be an alkali metal or an alkaline earth metal, and the collected discharge product may include oxidation products of the alkali metal or alkaline earth metal, such as oxides, peroxides, or hydroxides of the alkali metal or alkaline earth metal. The discharge product may also be a raw material in the process of forming an alkali metal, an alkaline earth metal, or an alloy thereof. In one aspect, as the aqueous solution (e.g., solution), metal ions such as Li + , Na + , or Ca 2+Solutions containing it can be cited. As non-limiting examples, lithium oxide products such as lithium hydroxide, lithium oxide, lithium carbonate, lithium bicarbonate, lithium oxalate, or combinations thereof may be dissolved in an aqueous solution to provide a lithium brine. The lithium brine may then be used as a raw material in the process of producing lithium metal or a lithium metal alloy. Similar sodium oxide products and processes for producing sodium metal are also known. Examples of sodium oxide products include, but are not limited to, sodium hydroxide, sodium oxide, sodium carbonate, or combinations thereof. Alkaline metal or alkaline earth metal brines (i.e., brines such as lithium brine or sodium brine) may have the advantage of being significantly more concentrated or of higher purity than natural brines. In one aspect, the brine may have an alkaline metal or alkaline earth metal concentration of 0.01 to 10 molar (M), 1 to 8 M, or 3 to 5 M. In one aspect, the content of impurities, i.e., metals other than alkaline metals or alkaline earth metals, may be 1 to 1000 parts per million (ppm), 10 to 500 ppm, or 50 to 100 ppm. In certain embodiments, the brine may be used as a raw material for the electrochemical deposition of metals through an electrolyte that conducts metal ions. Such electrolytes may be solid electrolytes or molten salts such as mixtures of alkaline metal or alkaline earth metal halides such as those of lithium or sodium. The solid electrolyte may be a solid polymer electrolyte or a solid inorganic electrolyte. The solid inorganic electrolyte may be a ceramic. In one aspect, the solid inorganic electrolyte is NaSICON, LiSICON, Na-β”-alumina, K-β”-alumina, lithium phosphate (Li3PO4), lithium titanium phosphate (Li x Ti y (PO4)3, 0 < x < 2 and 0 < y < 3), lithium aluminum titanium phosphate (Li x Al y Ti z (PO4)3, 0 < x < 2, 0 < y < 1, and 0 < z < 3), Li 1+x+y (Al a Ga 1-a ) x(Ti b Ge 1-b ) 2-x Si y P 3-y O 12 (0 ≤ x ≤ 1, 0 ≤ y ≤ 1, 0 ≤ a ≤ 1, and 0 ≤ b ≤ 1), lithium lanthanum titanate (Li x La y TiO3, 0 < x < 2 and 0 < y < 3), lithium germanium thiophosphate (Li x Ge y P z S w , 0 < x < 4, 0 < y < 1, 0 < z < 1, and 0 < w < 5), lithium nitride (Li x N y , 0 < x < 4, and 0 < y < 2), Li x Si y S z , glass (0 < x < 3, 0 < y < 2, and 0 < z < 4), Li x P y S z , glass (0 < x < 3, 0 < y < 3, and 0 < z < 7), Li2O, LiOH, Li2CO3, LiAlO2, Li2O - Al2O3 - SiO2 - P2O5 - TiO2 - GeO2 type ceramic, garnet type ceramic (Li 3+x La3M2O 12(M = Te, Nb, Zr), or a combination thereof. In one aspect, the solid polymer electrolyte may include a lithium salt, a polymeric ionic liquid including poly(diallyldimethylammonium trifluoromethanesulfonyl)imide (TFSI), poly(1-allyl-3-methylimidazolium trifluoromethanesulfonylimide), poly(N-methyl-N-propylpiperidinium bis(trifluoromethanesulfonyl)imide), or a combination thereof. In one aspect, the solid polymer electrolyte may include a lithium salt and an ion-conductive polymer including polyethylene oxide (PEO), polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP), polyvinyl sulfone (polysulfone), polypropylene oxide (PPO), polymethyl methacrylate, polyethyl methacrylate, polydimethylsiloxane, polyacrylic acid, polymethacrylic acid, polymethyl acrylate, polyethyl acrylate, poly-2-ethylhexyl acrylate, polybutyl methacrylate, poly-2-ethylhexyl methacrylate, polydecyl acrylate, polyethylene vinyl acetate, a phosphate ester polymer, a polyester sulfide, polyvinylidene fluoride (PVDF), Li-substituted Nafion, or a combination thereof.

[0051] Further details of the process for producing lithium or sodium metal, or lithium- or sodium-containing products from the raw materials are known to those skilled in the art of collection and purification of alkali metal-bearing brines, such as brines supplied from natural geological sources.

[0052] As shown in FIGS. 3A-3D, brines such as alkali metal or alkaline earth metal brines such as lithium or sodium brine may be used as a raw material for producing the corresponding metal by electrodepositing an alkali metal or alkaline earth metal, such as lithium or sodium, from the brine through an electrolyte onto a metal current collector. In further detail, and as shown in FIG. 3A, a current collector and an electrolyte assembly 300 including the current collector 305 and an electrolyte 320 are Li + or Na+ alkali metal or alkaline earth metal cations i such as + It may be contacted with brine 325 which is a solution containing. The electrolyte may be a solid electrolyte, the solid electrolyte may be disposed on the current collector, and the brine may be prepared from battery discharge products.

[0053] Next, as shown in FIG. 3B, the metal 310 may be electrodeposited from the brine 325 onto the current collector 305 on the surface facing the electrolyte 320, for example, between the current collector and the solid electrolyte, to provide a current collector-metal electrode or a current collector-metal electrode-electrolyte, or a metal electrolyte-electrolyte subassembly. The subassembly may be used to provide a metal-air battery. The metal-air battery may be provided by disposing a suitable metal such as Li, Na, K, Ca, Mg, Zn, Fe, or Al on the current collector of the surface to which the metal is adhered. The brine may contain lithium or sodium to provide a lithium-air battery or a sodium-air battery.

[0054] Alternatively, as shown in FIG. 3C, the collected discharge products of the metal-air battery may be used to form brine, and the alkali metal or alkaline earth metal cations from the brine may be transported through the solid electrolyte and incorporated into the host 315 to form an intercalation compound that reversibly stores the metal. Many intercalation compounds are known to those skilled in the art of metal ion batteries such as Li-ion or Na-ion batteries that can reversibly incorporate alkali metals, and thus may be used as the positive or negative electrode of a rechargeable battery. The host may then be used as the electrode of the battery. Alternatively, a metal, for example, an alkali metal, may be recovered from the intercalation compound by deintercalation. For example, a liquid phase compound such as a composition used as a liquid electrolyte in a metal ion battery may also be used. Such a liquid may contain, for example, an alkyl carbonate. Further details of solid or liquid phase compounds capable of storing alkali metals such as intercalation oxides are known to those skilled in the art of primary batteries as well as rechargeable lithium and sodium batteries.

[0055] (5) A battery containing processed discharge products The electrodeposited metal may be used to provide the metal electrode assembly of a metal-air battery as shown in FIG. 3D. The metal electrode assembly may include a current collector 305 and electrodeposited metal 310 on the current collector. In the battery, there are also present an electrolyte such as electrolyte 320 and an air electrode 330 on the electrolyte. The electrolyte 320 in the metal-air battery may be the same as or different from the electrolyte used in electrodeposition. Thus, the discharge products of the metal-air battery may then be used in metallic form at the metal electrode of the metal-air battery. The metal electrode may be used in a sub-assembly including a current collector and an electrolyte on the current collector, and depending on the state of charge, the metal-air battery may further include a metal electrode disposed on the current collector.

[0056] The metal may include Li, Na, K, Ca, Mg, Zn, Al, or combinations thereof. The discharge products may be oxides, hydroxides, carbonates, bicarbonates, oxalates, or another metal compound, and the discharge products may then be refined or processed, for example, to produce metal salts using anions different from those of the discharge products prior to the formation of the metal.

[0057] As a non-limiting example, the discharge product may be converted to a metal halide such as an alkali metal halide or an alkaline earth metal halide, and the metal halide may be used to produce a metal. In further detail, an electrolytic or electrochemical method may be used to produce a metal from the metal halide. Non-limiting examples of such methods include the electrolytic decomposition of the metal halide into the metal and the halogen. In some embodiments, the metal halide is a chloride. For example, lithium chloride (or sodium chloride) may be electrolytically decomposed to form lithium metal (or sodium metal) and chlorine gas, respectively. Other metal chlorides such as calcium chloride or magnesium chloride may be similarly decomposed. Also, additional metal halides, including but not limited to aluminum chloride, tin chloride, alkali metal chlorides, alkaline earth chlorides, or combinations thereof, may be added to lower the melting temperature of the chloride mixture. For example, a mixture of aluminum chloride such as AlCl3 and LiCl, NaCl, KCl or the like, or combinations thereof, has a lower melting temperature than the end members of the pure metal chlorides and is known to form binary, ternary and multicomponent eutectic compositions. Similarly, a mixture containing calcium chloride CaCl2 and LiCl, NaCl, KCl, or combinations thereof, may form a eutectic mixture with a liquid composition having a melting point lower than the melting point of the pure salt. Thus, a mixture of metal chlorides may enable a lower electrolysis temperature for the deposition of the constituent metals from the metal chloride mixture. The metal chloride mixture may include a liquid, solid, or semi-solid containing at least one of a liquid composition and a solid composition. The chlorine gas produced by electrolytic decomposition, or the corresponding halogen gas in other metal halides, may be used to produce chlorinated products as part of the intended system. Thus, the disclosed subsystem may include a system for producing a metal or metal electrode by such a method.

[0058] In some embodiments, the halide mixture may be used to form the metal electrode of a metal-air battery by electrodepositing a metal directly onto a current collector. For example, the negative electrode of a metal-air battery may be formed, at least in part, by electrodepositing a metal onto the current collector of the battery. Alternatively, the halide mixture may be used to form a metal electrode for use within a metal-air battery by electrodepositing a metal through an electrolyte as shown in FIG. 3B. In one aspect, the electrolyte 320 of the electrolyte layer may include a solid electrolyte, a liquid electrolyte, a gel electrolyte, or a combination thereof. The use of a solid electrolyte is mentioned. Accordingly, the described system provides for forming a metal or metal electrode by such methods.

[0059] In one aspect, the discharge product may be used for other purposes, and the metal electrode of the metal-air battery may be formed from other starting materials (not derived from the discharge product). For example, the metal halide electrolysis process described herein for forming a metal may include a metal halide supplied from another source (i.e., not from the discharge product of the metal-air battery) as a raw material. For example, a mixture containing LiCl and CaCl2 from which Li metal can be produced electrolytically may be obtained from a mined source or a recycled source other than the discharge product of the metal-air battery. Similarly, a mixture containing NaCl and CaCl2 from which Na metal is produced electrolytically may be supplied from other than the discharge product of the metal-air battery or may be from a recycled source other than the discharge product of the metal-air battery. Such materials and methods may have economic and supply chain advantages. Such methods may enable the use of lower purity and less expensive sources of metal halides such as NaCl and / or CaCl2 obtained from geological or industrial brines such as seawater, desalinated brine, or brine from oil or natural gas extraction for forming a metal. In such examples, the discharge product of the metal-air battery may be of higher purity and higher market value and may be used in applications requiring higher purity such as for forming Li-ion and Na-ion cathode materials or solid electrolytes. In one aspect, the discharge product of the metal-air battery may have a purity of 80 to 99.9999 weight percent (wt%), 85 to 99.99 wt%, or 90 to 99.9 wt% based on the total weight of the discharge product.

[0060] Brine produced from the discharge product of the metal-air battery may be used to form a lithium or sodium negative electrode material by electrochemical insertion or alloying. For example, the negative electrode material may be provided by intercalating the metal from the brine into another host such as graphite, hard carbon, silicon, tin, aluminum, or a metal oxide. In one aspect, lithium or sodium may be combined with carbon or silicon to provide a negative electrode material for the metal-air battery.

[0061] The discharge products may be concentrated to provide metal salts for sale or use. For example, LiOH and Li2CO3 may be used as starting materials for the production of lithium-ion battery cathode materials such as LiFePO4, LiCoO2, lithium nickel-cobalt-aluminum oxide (NCA), lithium nickel-manganese-cobalt oxide (NMC), or lithium manganese oxide (LMO). Alternatively, LiOH and Li2CO3 may be used as starting materials for the production of lithium battery anode materials such as lithium titanate spinel (LTO), lithium conductive solid electrolytes such as lithium lanthanum zirconium oxide (LLZO), or lithium superionic conductors (LiSICON). Similarly, NaOH and Na2CO3 may be used for the production of sodium-ion battery cathodes and sodium solid electrolytes. Variations and derivatives of these compounds are known to those skilled in the art. Similar compounds may be used to produce sodium-ion battery electrodes and sodium-ion conductive solid electrolytes such as NaSICON or sodium beta-alumina solid electrolytes. Lithium salts, sodium salts, or other metal salts taken as discharge products may be used in the production of such electrodes or electrolyte materials.

[0062] Negative electrode The negative electrode of a metal-air battery may include any suitable metal. The metal may be an alkali metal, an alkaline earth metal, a transition metal, a metalloid, a post-transition metal, or a combination thereof. In some embodiments, the negative electrode may be an alkali metal or an alkaline earth metal. The alkali metal may be Li, Na, K, Rb, Cs, or a combination thereof, and the alkaline earth metal may be Mg, Ca, or a combination thereof. The transition metal may be iron, zinc, or the like, or a combination thereof. The post-transition metal may be aluminum or the like. The metalloid may be silicon or the like. Combinations including at least one of the above may be used.

[0063] For example, as the metal of the negative electrode of a metal-air battery, zinc, iron, or aluminum can be mentioned. The metal-air battery may be a zinc-air, iron-air, or aluminum-air battery, and the discharge product may be formed at the air electrode.

[0064] Electrolyte The electrolyte of the metal-air battery may be any suitable liquid, aqueous or non-aqueous, or an ionic liquid. In one aspect, the metal-air battery may include an alkaline electrolyte, and the discharge product may be formed on the air electrode (i.e., the gas diffusion electrode), on the surface of the gas diffusion electrode material, on the outer surface of the gas diffusion electrode material, or inside the gas diffusion electrode material. The aqueous electrolyte may include hydroxides such as alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide, or combinations thereof in water. The non-aqueous electrolyte may include a non-aqueous liquid such as C1-C4 carbonates, C1-C4 alcohols, C1-C4 ketones, or combinations thereof, and any suitable salt such as lithium borate or the like. The ionic liquid may be an aluminum-alkali metal chloride such as an ionic liquid having a melting point of less than 100 °C, for example, 10 °C to 200 °C or 20 °C to 150 °C, such as a chloroaluminate ionic liquid.

[0065] In one aspect, the electrolyte may be a solid electrolyte. The solid electrolyte may be selected to conduct selected metal ion(s). The solid electrolyte may conduct lithium, sodium, aluminum, zinc, iron, or combinations thereof. Examples of solid electrolytes include solid polymer electrolytes (SPEs) having appropriate lithium or sodium conductivity, such as the same conductivity as polyethylene oxide (PEO) doped with a lithium salt such as lithium chloride. Block copolymers including PEO, as well as copolymers and copolymer blends, may also be used. The SPE may be attached to the current collector using any suitable process such as casting, coating, spraying, vapor deposition, or the like. In some embodiments, casting a solution containing the SPE or deposition of a vapor containing the SPE may be used. Other representative methods for disposing the SPE on the current collector include solvent casting, melt casting, dip coating, extrusion, co-extrusion, slot die coating, spray coating, electrostatic coating, electrophoretic deposition, inkjet deposition, three-dimensional printing or the like, or combinations thereof. The SPE may be disposed in the form of a solution, a molten phase, droplets, a dry solid, or a dry powder.

[0066] Examples of solid electrolytes include inorganic solid electrolytes. Non-limiting examples include lithium lanthanum titanate (LLTO, e.g., Li7La3Zr2O 12 ), modified examples of doped LLTO (e.g., LLZTO, Li 6.75 La3Zr 1.7 Ta 50.25 O 12Or derivatives thereof, or lithium-ion and sodium-ion conductive solid electrolytes such as inorganic solid electrolytes having a garnet structure such as compositions or structures in the lithium superionic conductor (LiSICON) or sodium superionic conductor (NaSICON) family. As used herein, the term "garnet" or "garnet-type" means that the compound has the same crystal structure as garnet, for example, Mg3Al2(SiO4)3. For example, solid electrolytes include beta-aluminas such as sodium and / or potassium beta-alumina (e.g., Na-β”-Al2O3 or K-β”-Al2O3), sulfides such as lithium phosphorus sulfide (β-Li3PS4, LPS) or lithium germanium phosphorus sulfide (LGPS), antiperovskites such as Li3OX or Li2OHX (where X is a halogen), or compounds containing cluster ions such as those containing NH2, BH4 or PS4 groups, for example Na 3-x O 1-x (NH2) x (BH4) (where 0 < x < 1), Li 3-x O 1-x (NH2) x (BH4) (where 0 < x < 1), or argyrodite materials such as Li6PS5X, Li 6-x PS 5-x X 1+x Or Li 6+x Si x P 1-x S5X (where X is a halogen such as Cl, Br, or I, and 0 < x < 1), etc., can be mentioned for stoichiometric or non-stoichiometric argyrodite materials.

[0067] Current collector The current collector may include any suitable electrical conductor and may include a transition metal, a metalloid, a post-transition metal, or a combination thereof. For example, the current collector may include copper, iron, titanium, zinc, aluminum, silicon, or a combination thereof. The current collector may include carbon such as graphite carbon, vitreous carbon, amorphous carbon, soot, carbon black, graphene, graphene oxide, carbon nanofiber, carbon nanotube or the like, or a combination thereof. In some embodiments, the current collector may include an electronically conductive polymer such as poly(3,4-ethylenedioxythiophene) (PEDOT). The current collector may include any suitable electronically conductive inorganic compound such as a metal oxide, a metal carbide, a metal nitride, a metal oxycarbide, a metal oxynitride or the like, or a combination thereof. Examples of such compounds include, but are not limited to, copper oxide, vanadium oxide, tin oxide, titanium carbide, titanium nitride or the like, or a combination thereof.

[0068] The term "electrically conductive" means that the current collector material has an electrical conductivity of greater than 10 -6 siemens per centimeter (S / cm), preferably greater than 10 -3 S / cm, more preferably greater than 1 S / cm, more preferably greater than 10 3 S / cm, or 10 -6 S / cm to 10 3 S / cm, or 10 -3 ~10 3 S / cm at the use temperature and is understood to mean that.

[0069] Method Also provided is a method of manufacturing a sub-assembly of a metal-air battery. In one aspect, the current collector, the metal electrode, and the solid electrolyte may be provided separately and joined to provide a sub-assembly of the metal-air battery. The metal electrode may be disposed on the current collector, and the solid electrolyte may be disposed on the metal electrode, for example, in a roll-to-roll process, to join the current collector, the metal electrode, and the solid electrolyte to provide a sub-assembly of the metal-air battery. Any of the current collector, the metal electrode, the solid electrolyte, and / or a sacrificial material such as a release film may act as a support or substrate to which the current collector, the metal electrode, and / or the solid electrolyte are attached to provide a sub-assembly of the metal-air battery.

[0070] The method of manufacturing is schematically shown in FIG. 4.

[0071] First, as shown in step (A) of FIG. 4, a current collector 410 is provided. The current collector may include any suitable conductor and may include a metal, a polymer, a ceramic, a composite, or a combination thereof having suitable properties such as a suitable conductivity.

[0072] Next, as shown in step (B) of FIG. 4, a solid electrolyte, or a solid electrolyte precursor 420, is disposed on the current collector from a suitable vapor phase, liquid phase, or solid phase source. Such a precursor may include a metal salt, which upon thermal decomposition leaves behind the components of the solid electrolyte. Such metal salts may include metal nitrates, sulfates, carbonates, oxalates, acetates, and alkoxides. In one aspect, the solid electrolyte is disposed from a suitable vapor phase, liquid phase, or solid phase source. The solid electrolyte may be deposited in the form of particles, or as shown in step (C) of FIG. 4, in the form of a layer. Alternatively, the solid electrolyte precursor may be deposited in the form of particles. In one aspect, a layer comprising particles of the solid electrolyte precursor is formed. The particles may be formed by depositing the precursor and then converting it to the solid electrolyte. In non-limiting examples, aqueous solutions, non-aqueous solutions, or suspensions of metal nitrates, sulfates, carbonates, oxalates, acetates, alkoxides, or combinations thereof may be used to provide particles, for example, utilizing sol-gel chemistry. Other methods of depositing the precursor to provide particles include chemical vapor deposition, for example, chemical vapor deposition of the precursor onto the solid electrolyte; electrophoretic deposition of particles from a liquid suspension; electrochemical deposition, for example, electrochemically creating a pH change adjacent to the current collector to promote metal hydroxide precipitation or cause electronic aggregation; electrostatic painting of the current collector with droplets, mist, or vapor of a composition comprising the precursor of the solid electrolyte; or spray coating or dip coating the current collector with a suspension comprising the precursor of the solid electrolyte. The foregoing methods are representative, and coatings, or roll-to-roll processes, and other methods known to those skilled in the art for curing such coatings, such as curing by ultraviolet or electron irradiation, are also mentioned. Further details of the foregoing methods may be determined by those skilled in the art without undue experimentation.

[0073] Thirdly, as shown in step (C) of FIG. 4, the solid electrolyte precursor is processed to provide the solid electrolyte 430. As initially deposited, the solid electrolyte may be in the form of a dense continuous layer or a porous continuous layer. Processing of the porous material may desirably increase the density to provide a dense material. Examples of the processing include heat treatment, for example, heat treatment at 100°C to 1000°C, 200°C to 800°C, or 300°C to 700°C. The precursor may be contacted with any suitable radiation from microwaves to gamma rays to convert the precursor to a solid precursor and / or densify the solid electrolyte. Alternatively, in some embodiments, the solid electrolyte precursor may be contacted with plasma to convert the precursor to a solid electrolyte.

[0074] Optionally, further processing may be used to modify the composition or structure of the solid electrolyte. For example, the solid electrolyte may be treated with radiation or heating while being deposited or after deposition. Representative methods for treating the deposited solid electrolyte include radiation heating, convection heating, microwave heating, plasma heating, or the like, or combinations thereof. Treatments can include treatment inside an oven or furnace with or without using a transfer device. The radiation source may provide radiation of any suitable frequency and / or wavelength. Examples of radiation include microwaves, infrared rays, visible light, near-ultraviolet light, ultraviolet light, X-rays, gamma rays, or combinations thereof. Radiation can include electrons or photons. Heating can include heating at any suitable rate, including rapid heating methods, the details of which may be determined by those skilled in the art. Representative rapid heating methods include microwave heating, plasma heating, spark plasma sintering, flash sintering, rapid thermal processing (RTP), rapid thermal annealing (RTA), UV sintering, blacklight sintering, or the like, or combinations thereof. Such methods, particularly blacklight sintering, are described in "Blacklight sintering of ceramics" by L. Porz, et al. Materials Horizons, DOI: 10.1039 / d2mh00177b, published in 2022; and "Microstructure and conductivity of blacklight-sintered TiO2, YSZ, and Li 0.33 La 0.57 TiO3,” incorporated herein by reference in its entirety.

[0075] In some embodiments, the solid electrolyte may initially exist as a porous or incompletely dense layer, and may further be densified, for example using one or more of the methods described above, to have preferably closed pores, or a density of at least 80% of the theoretical density of the compound containing the solid electrolyte, preferably greater than 90% of the theoretical density, preferably a density of 85% to 99.9999% or 90 to 99.99% of the theoretical density, to produce a substantially densified layer. The densified layer may have an average thickness of 1 nanometer (nm) to 1 millimeter (mm), preferably 10 nm to 100 micrometers (μm), or preferably 1 μm to 50 μm. The thickness and average thickness may be determined by microscopy such as scanning electron microscopy of a cross-section of the solid electrolyte layer.

[0076] The densified layer may have a density gradient, or multiple layers having different densities may be used. For example, the densified layer may include a first densified layer adjacent to a second, less dense layer of the solid electrolyte. Examples of such densified layers adjacent to a less dense layer are shown in FIGS. 4a and 4e of L. Porz, et al., "Microstructure and conductivity of blacklight-sintered TiO2, YSZ, and Li 0.33 La 0.57 TiO3," which is hereby incorporated by reference in its entirety for all purposes.

[0077] Next, as shown in step (D) of FIG. 4, the metal electrode layer 440 is introduced between the current collector and the solid electrolyte 430 by transporting metal ions through the solid electrolyte layer and then reducing to form a metal electrode between the current collector and the electrolyte. A counter electrode 450 is also shown. The counter electrode may comprise any suitable material and may include metals, polymers, ceramics, composites, or combinations thereof having suitable conductivity and material compatibility, such as material compatibility with brine or metal halides.

[0078] Such deposition may be generated by having a chemical potential gradient between the current collector and the source of metal atoms such that the metal chemical potential is lower in the current collector. Such deposition may also be generated by applying a potential between the current collector and a counter electrode disposed away from the current collector - solid electrolyte sub - assembly as shown in step (D) of FIG. 4 to create a potential gradient, causing the migration of metal ions from the metal source through the solid electrolyte to the current collector and reducing to form the metal electrode 430. The source from which the metal is electrodeposited may include one or more of the previously mentioned sources of metal such as brine or metal halides.

[0079] Next, as shown in step (E) of FIG. 4, the air electrode 460 is deposited on the metal electrode. In one aspect, specifically, a metal negative electrode and a solid electrolyte may be provided on a sub - assembly including the current collector, and the air electrode may be disposed on the solid electrolyte to provide a metal - air battery 400.

[0080] Recharge A metal-air battery may be mechanically recharged by replacing the negative electrode subassembly with a subassembly having a greater amount of metal. As discussed previously with reference to FIGS. 3A-3D, when a metal-air battery is discharged, the metal is converted into a discharge product. The metal-air battery may be recharged by replacing the discharged current collector-metal electrode-electrolyte subassembly with a subassembly having a greater amount of metal. Similarly, metal may be provided by processing the discharge product, e.g., collecting the discharge product, forming a brine, and electrodepositing the discharge product onto the current collector, to provide a recharged current collector-metal electrode-electrolyte subassembly. Mechanical recharging may include replacing the discharged subassembly with a recharged subassembly. In one aspect, mechanical recharging may be performed while the metal-air battery is in a system or device powered thereby, and components, e.g., the current collector-electrolyte subassembly, or the current collector, may be replaced. In other embodiments, the metal-air battery may be removed, inspected, rebuilt, or remanufactured before being returned to service. In other embodiments, the discharged metal-air battery may be recycled or disposed of after at least a portion of the discharge product has been removed therefrom, and a newly manufactured metal-air battery may be used instead.

[0081] Subsystems or methods for providing a charged metal-air battery also include a system or method configured to provide and distribute the charged battery to powered devices and systems. A "charging station" for such purposes may include a facility that assembles a charged battery cell by collecting the discharged product, the discharged component, and / or a "charged" state metal electrode or subassembly of the metal-air battery that has undergone processing of the discharge product to have metal. The facility may replace the discharged subassembly with a recharged subassembly, remove the discharged subassembly from the battery, install the recharged subassembly, or distribute components such as electrodes, batteries, or battery systems to powered devices or systems.

[0082] Equipment for processing discharge products to produce components for a charged battery system or such equipment for manufacturing batteries may be located inside or installed at the location of use of the metal-air battery. Non-limiting examples include, for example, service hubs for organization-owned cars, buses, trucks, and / or trains. Other examples include the integration of such equipment at airports for electric aircraft using such batteries, or such equipment installed on ships.

[0083] Device: Vehicle The exceptionally high energy density and low material cost of metal-air batteries, particularly alkali metal-air batteries, are attractive for hybrid and electric aircraft among other applications. Without wishing to be tied to theory, the limitation of metal-air batteries with retained discharge products is that the discharge reaction increases the mass and volume of the battery. For example, Li metal increases its mass by 5.61 times upon oxidation to LiO2, and Na metal increases its mass by 2.39 times upon oxidation to NaO2. Thus, as the metal-air battery discharges, the mass of the battery increases, which can reduce the driving range and payload capacity of the vehicle powered by the battery. In contrast, vehicles powered by petroleum fuels such as gasoline, diesel, or propane decrease in mass as the fuel is burned. In the disclosed system, a metal-air battery, method of use, and vehicle powered by a metal-air battery are provided to mitigate this drawback. In the disclosed system, the air electrode of the metal-air battery may be configured such that natural or forced convection removes discharge products from the electrode. The discharge products thus removed may be discarded from the vehicle as the vehicle is propelled.

[0084] In one aspect, as the discharge products are removed from the air electrode or after the discharge products are removed from the air electrode, the discharge products may optionally isolate greenhouse gases or other contaminants while present within the air electrode.

[0085] In a selected embodiment, the metal-air battery may be used to power an electric aircraft. An embodiment where the metal is an alkali metal is mentioned. The use of a sodium-air battery is mentioned. As shown in FIG. 1, the discharge products of the Na-air battery may accumulate at the air electrode. In the aircraft, the discharge products are removed. As shown in FIG. 5, as the aircraft flies, the aircraft may receive an air flow that can be directed, for example, by using a vent cylinder having channels or a flow field, or natural convection, such that the air flow is directed towards the air electrode to remove the discharge products. The air flow may pass by, over, or through the air electrode to remove at least a portion of the discharge products. The air flow may also be generated by using forced convection, at least in part, for example, by a fan or turbine that directs air. The fan or turbine may be at least partially powered by the metal-air battery.

[0086] As shown in FIG. 5, the discharge products are removed by the air flow and discharged or discarded from the aircraft 510. In an example of a Na-air battery, the discharge products may then react with carbon dioxide (CO2) in the air to form carbonates such as Na2CO3, or bicarbonates such as NaHCO3 if water is present. After the discharge products are discharged, as the discharge products fall to the ground through the atmosphere, or after the discharge products land, carbonates may form while the sodium discharge products are present within the air electrode of the battery. In an aqueous medium, the discharge products will ultimately form bicarbonates, and thus, each mole of Na discharged from the battery will react with 1 mole of CO2. Since the metal reacts with air to form carbonates, for example, sodium metal is converted to sodium carbonate or sodium bicarbonate, the discharge products of the battery may have CO2 recovered and sequestered from the atmosphere, also known as direct air capture (DAC), and perform a beneficial function to the environment and society. When the carbonates arrive in a body of water such as the ocean, or are transported to the body of water by other means, the carbonates may further perform a beneficial function of increasing the alkalinity of the body of water.

[0087] In embodiments where battery discharge products are not collected, the use of low-cost metals such as sodium is preferred. Similarly, in addition to the value provided when propelling a vehicle, there can be economic benefits from the recovery and sequestration of greenhouse gases such as carbon dioxide, depending on the price of the recovered carbon and the like. As an illustration of an operating model that may be included, systems and processes are disclosed in which NaCl is the starting material and is electrolytically reduced to Na metal. Excluding the value of the Cl2 gas that may be co-produced, the cost of producing Na metal, including the cost of the NaCl feedstock, can be approximately $0.44 per kilogram (kg). When using Na2O as the discharge product in a Na-air battery with an average discharge voltage of 2 volts (V), the complete oxidation of Na metal produces electricity at a cost of $0.19 per kilowatt-hour (kWh). Utilizing a CO2 price of $100 per ton for carbonation to Na2CO3, the benefit for the recovery and sequestration of CO2 is $0.08 per kWh, and the net cost of the supplied power for the battery system is $0.11 per kWh. The net cost of $0.11 per kWh is comparable to the cost of the supplied power of other batteries with much lower energy density than the Na-air battery. For example, it is comparable to the supplied power of a Li-ion battery with a cycle life of 1000 cycles, or $110 per kWh. The net cost of $0.11 per kWh is also comparable to the propulsion cost of an aircraft using jet fuel.

[0088] In one embodiment, the metal-air battery includes a metal electrode that is at least partially liquid. The liquid may include any suitable metal, including an alkali metal, an alkaline earth metal, or a combination thereof, preferably an alkali metal, more preferably sodium metal. In a non-limiting example, the alkali metal may be sodium. At the operating temperature of the metal-air battery, the metal electrode may be a liquid sodium alloy, an example of which is a Na-K alloy, or a semi-solid electrode having at least one liquid metal and one solid phase. Liquid sodium has a melting temperature of about 98 °C. Without wishing to be bound by theory, the advantage of having a metal electrode that is a liquid alloy or semi-solid metal may be that the operating temperature of the metal-air battery can be reduced. In one aspect, a Na-K composition that provides a liquid containing Na at a temperature below the melting temperature of sodium metal is selected. For example, as shown in the binary phase diagram of Na-K, a Na-K alloy having about 69 mole percent (mol%) potassium can be liquid at a temperature of -13 °C corresponding to the eutectic composition and temperature of the Na-K alloy. In a Na-K composition having 33 mol% to 97 mol% potassium based on the total content of the alloy, the liquid of the eutectic composition can be present in the electrode at a temperature greater than the eutectic temperature of the alloy. At temperatures above the disclosed Na-K electrode composition and eutectic temperature, the negative electrode can be a semi-solid electrode having a solid Na2K phase coexisting with the Na-K liquid, or a K-rich solid phase coexisting with the Na-K liquid. In a Na-K composition having less than about 40 mol% potassium and a temperature above 7 °C, the Na-K negative electrode can be a single liquid phase or a semi-solid electrode containing a solid sodium-rich phase coexisting with the Na-K liquid.

[0089] The operating temperature of a metal-air battery may include a wide range of temperatures, from below room temperature (e.g., 25 °C), such as a low temperature of -60 °C corresponding to the Arctic region, or even lower, temperatures found in space or extraterrestrial environments, to temperatures well above room temperature, such as 200 °C, 300 °C, 500 °C, 1000 °C, or even higher for high-temperature batteries operating up to even higher temperatures. Thus, in the example of a sodium-air or lithium-air battery, by way of non-limiting example, the operating temperature of the battery may be below the melting point of sodium metal (approximately 98 °C) or lithium metal (approximately 180.5 °C) such that the metal is solid during operation of the battery, or may exceed the melting point of either metal such that the metal is liquid during operation of the battery.

[0090] The metal-air battery may include a solid electrolyte. Any suitable solid electrolyte may be used. Representative solid electrolytes such as garnet, beta-alumina, and antiperovskite, argyrodite, NaSICON electrolyte, or combinations thereof have been mentioned. Suitable solid electrolytes are described further above.

[0091] The solid electrolyte may be in the form of a container 630 within which the metal electrode 640 is present. As shown in FIG. 6, the container 630 may have any suitable shape, may be linear or curved, spherical, or cylindrical, and may be in the form of a closed-end tube. The tube may have any suitable cross-sectional shape, and the cross-section may be linear, curved, rectangular, square, circular, or elliptical. Any suitable cross-sectional shape may be used. The tube may have a cross-sectional shape with a larger perimeter-to-surface area ratio than such geometric shapes. Similarly, the container may have a height or length-to-width or diameter ratio greater than 1 for providing a tube, or less than 1 for providing a tray or box shape, and may have, for example, a surface area-to-volume ratio larger than such geometric shapes, for example by including a corrugated or reticulated wall.

[0092] The metal-air battery may further include a negative electrode lead 620 that is in electrical communication with and optionally physically contacts the metal electrode 640. In one aspect, the negative electrode lead is connected to the current collector 645 of the metal electrode. Similarly, a positive electrode lead 665 is provided, and the positive electrode lead is in electrical communication with the air electrode 660. The metal electrode may be disposed inside or on the concave surface of the container. The air electrode may be installed on the outer surface or convex surface of the container. The air electrode enables an electrochemical reaction of metal ions i such as Li + or Na + with oxygen, carbon dioxide, carbon monoxide, nitrogen, nitrogen oxide, or a combination thereof. +

[0093] Similarly, a protective layer (e.g., a surface protective layer) 670 is provided. The protective layer protects the metal electrode and prevents or avoids reaction with air. The protective layer may be disposed on the metal electrode and protect the metal electrode from reaction with the surrounding atmosphere. The protective layer may contain a liquid. A non-limiting example is an organic liquid that has limited reactivity when in contact with the metal electrode and limits the transport of air or water to the negative electrode. In one aspect, the metal of the metal-air battery present as a solid or liquid may be admixed with an inert liquid to provide easier and safer handling, storage, or delivery of the metal to the battery that generates power. The liquid is preferably non-reactive with respect to the metal. The liquid may be hydrophobic or hydrophilic and may be wettable or non-wettable with respect to the surface of the metal. In a preferred embodiment, the liquid is non-reactive and wettable with respect to the surface of the metal, i.e., has a contact angle between the liquid and the metal of 0° to 90°, 5° to 80°, or 10° to 70°. Non-limiting examples of the liquid include hydrocarbon oils, silicone oils, organic or inorganic liquids, polymers, emulsions, gels, suspensions of particles in liquids, or the like.

[0094] ​In a specific embodiment where the metal electrode contains an alkali metal, the liquid may contain a hydrophobic compound such as an oil such as mineral oil or a hydrocarbon liquid derived from petroleum. In an embodiment where the metal electrode contains lithium, sodium, potassium, or an alloy thereof, the protective layer may contain mineral oil and may be effective in eliminating the reaction between the metal electrode and air. The metal-air battery may have a configuration opposite to the configuration shown in FIG. 6, i.e., a configuration having a metal electrode on the outer or concave surface of the container and an air electrode on the inner or convex surface of the container.

[0095] The container may be of an open-end form. As shown in FIG. 7, the container 710 contains a solid electrolyte and is in the form of a tube and may provide a fluid such as air flowing through the container. The metal electrode 740 may be disposed outside the container 710, and the discharge product may be formed at the air electrode 760. Also shown in FIG. 7 are a protective layer (e.g., a surface protective layer) 770, such as mineral oil, a negative electrode current collector 745, and a negative electrode lead 720. Although preferred embodiments where the metal is sodium are shown in FIGS. 6 and 7, any suitable metal or metal alloy may be used.

[0096] The metal-air battery may include a container including the configuration shown in FIGS. 6 and 7. Also, the metal-air battery may include a plurality of containers, the containers may be closed-end or open-end tubes, and may further include any suitable combination of channels connected in any suitable configuration, but the configuration is not limited thereto.

[0097] The metal electrode may be generated from a metal salt using a solid electrolyte electrochemical cell. In some embodiments, the solid electrolyte electrochemical cell has an ion transport rate of the selected metal of the metal electrode that is greater than about 0.9, preferably greater than 0.95, preferably greater than about 0.99, more preferably greater than 0.999, or 0.9 to 0.99999, or 0.95 to 0.9999. That is, the solid electrolyte may effectively be a single ion conductor and may advantageously provide a metal electrode having a purity corresponding to the ion transport rate. In one aspect, the transport rate is 0.999, and a metal having a purity of 90% to 99.999%, 95 to 99.99%, or about 99.9 mol% based on the total metal content of the metal may be generated for use in a metal-air battery.

[0098] The metal-air battery may be combined with an electrolysis unit having a solid electrolyte to provide a combined system having the metal-air battery and the electrolysis unit. The metal-air battery may be integrated with an electrolysis unit (e.g., an electrochemical cell that generates a metal), as shown in FIG. 8. The integrated system 800 includes a metal-air battery subunit 802 and an electrolysis subunit 804. The electrochemical cell that generates the metal uses input power to generate at least one metal from raw materials, and the metal may then be used as the negative electrode of the metal-air battery. A negative electrode lead 820 connected to a current collector 845 is included within the metal-air battery subunit. A protective layer 870 protects the metal electrode 840. In the integrated system shown in FIG. 8, metal ions are transported from the electrolysis subunit to the metal-air battery subunit through the wall of a container 810 containing a solid electrolyte. Discharge products 860 may be formed at the air electrode 860. The electrolysis unit may contain a brine 825 containing metal ions corresponding to the metal of the metal electrode.

[0099] The solid electrolyte of the integrated system may include a single solid electrolyte or any suitable combination of solid electrolytes. The solid electrolyte may be selectively transport metal ions and may have a transport rate greater than about 0.9, preferably greater than 0.95, preferably greater than about 0.99, more preferably greater than 0.999, or 0.9 to 0.99999, or 0.95 to 0.9999. Therefore, the solid electrolyte may be selected to produce a selected metal or a selected combination of metals, such as a selected combination of metals for an alloy. For example, the electrolytic cell 804 may contain brine 625 containing a metal salt as a metal source in the brine. The metal salt may include more than one alkali metal salt, such as a lithium salt and a sodium salt. Thus, the solid electrolyte of the container 810 of the electrolytic cell may include both a lithium-conductive solid electrolyte and a sodium-conductive solid electrolyte, and may be operated to produce both high-purity lithium and high-purity sodium at a ratio selected by the relative rates of production of the individual metals through each solid electrolyte. For example, the product of the current through each solid electrolyte and the operating time may be used to determine the time-averaged absolute amount of each metal produced, and may then be used alone or as a mixture or alloy with one or more other elements.

[0100] Any suitable combination of metal salts may be used in the brine 825 within the electrolytic cell to produce high-purity metal. Metal hydrides; metal halides such as metal chlorides, metal bromides or metal fluorides; metal chalcogenides such as metal sulfides or metal selenides; metal carbonates; metal oxides; or combinations thereof may be used within the electrolytic cell. The metal salts may be liquid or solid. As a non-limiting example, a mixture of sodium chloride and calcium chloride may be used to lower the melting point of the mixture as compared to sodium chloride alone. A sodium ion solid electrolyte such as sodium beta alumina or NaSiCON may be used as the solid electrolyte within the electrolytic cell to enable the electrochemical production of high-purity sodium metal. When sodium is depleted from the mixed sodium-calcium chloride, NaCl may be added to maintain the desired composition of the feed material within the electrolytic cell. Simultaneously with the sodium metal reduction, oxidation of chloride ions to chlorine may occur. Chlorine co-products from the cell may advantageously be used to produce chlorinated products such as chlorine bleaching agents, cleaning solutions, etc., such as chlorine dioxide solution, vinyl chloride, polyvinyl chloride, or chlorine gas. Similarly, lithium chloride-calcium chloride salts used with a lithium-conductive solid electrolyte such as LiSICON or lithium lanthanum zirconium oxide (LLZO, garnet-type lithium conductor) or derivatives thereof may be used to produce lithium metal and chlorinated co-products.

[0101] Another example of a metal salt mixture that can be used to produce high-purity sodium metal is the Na-S system, which may contain various sodium sulfides used alone, or as mixtures with each other, or with sulfur. The Na-S solution is available above 250 °C, while pure sulfur melts at 235 °C. Both a single liquid phase composition or a semi-solid composition may be used, and the sodium metal obtained therefrom may be reduced at the cathode of the electrochemical cell using a sodium solid electrolyte such as sodium beta alumina. As sulfur is oxidized at the anode, the feed material may become sulfur-rich accordingly, and elemental sulfur may be obtained as a co-product of the cell.

[0102] In one aspect, the first metal salt may be converted to a second metal salt, and the second metal salt may be used as an input material for generating metal. As an example, NaCl may react with sulfur to generate sodium sulfide, and the sodium sulfide may then be used in an electrochemical cell to generate at least sodium metal and sulfur as a co-product.

[0103] Handling of Metals In various embodiments, the metal of a metal-air battery that exists as a solid or liquid may be admixed with a protective fluid to provide easier and safer handling, storage, or delivery of the metal to the metal-air battery that generates power. The protective fluid is preferably inert, meaning that it has limited reactivity when in contact with the metal. The protective fluid may be hydrophobic or hydrophilic, and may be wetting or non-wetting with respect to the surface of the metal. In a preferred embodiment, the protective fluid is non-reactive and wetting at the surface of the metal. Non-limiting examples of the protective fluid include hydrocarbon oils, silicone oils, ionic liquids, polymers, emulsions thereof, or gels thereof. The metal may be in the form of suspended particles in the protective fluid.

[0104] The protective liquid may have a density greater than that of the metal, and thus the metal may float as a solid or liquid on the surface of the protective fluid, or the metal may have a density less than that of the metal, and the solid or liquid metal may sediment in the protective fluid and may be covered by the protective fluid. The protective fluid may serve to protect the metal from exposure to the atmosphere, regardless of whether the metal is a solid or liquid. As shown in FIG. 9, the protective fluid may float on top of the solid or liquid metal by having a density less than that of the metal in order to form a protective layer.

[0105] Without wishing to be bound by theory, the advantages of Na and denser metals over Li are that solid Li metal has a density of 0.5 grams per cubic centimeter (g / cm 3has a density such that there is less of the non-reactive liquid selected from those having a density lower than lithium, and thus the protective layer containing mineral oil or hydrocarbon does not float on top of the solid or liquid metal. Na metal has a higher density and deposits in many available oils, facilitating the protection scheme of FIG. 9. Crude petroleum has a density of 0.8 - 0.9 g / cm 3 and silicone oil has a density of 0.74 g / cm 3 to 1.06 g / cm 3 within the range, and both mineral oil and paraffin have a density of about 0.8 g / cm 3 and kerosene and diesel fuel have a density of 0.8 g / cm 3 and gasoline has a density of 0.74 g / cm 3 . Solid Na metal has a density of 0.97 g / cm 3 at room temperature and 0.95 g / cm 3 at the melting point, and liquid Na metal has a density from 0.93 g / cm 3 at the melting point to 0.86 g / cm 3 up to 400 °C. Thus, there are many options for hydrophobic oils having a density less than Na, and thus the solid or liquid Na metal deposits and is protected from exposure to the atmosphere. In one aspect, a combination of protective fluids may be used to provide a stratified protective layer. The combination of the solid or liquid metal and the protective liquid may be stratified as shown in FIG. 9. FIG. 9 is a schematic cross-sectional view of a system including a metal-air battery containing a liquid sodium metal electrode floating on top of a non-reactive liquid having a density higher than that of liquid sodium. The sodium may be introduced into the system at any vertical point of the container as a liquid or as solid sodium, provided that the temperature at the top of the non-reactive liquid exceeds the melting point of the metal.

[0106] In one aspect, the metal may be present as droplets or particles having a minimum cross-sectional dimension in the range of 1 micrometer (μm) to 1 meter (m), preferably 10 μm to 0.1 m, more preferably 100 μm to 0.01 mm. Such metal may be immersed in a protective fluid or may be wetted or coated by the protective fluid. The volume ratio of the protective fluid to the metal may be in the range of 0.001 to 10 or 0.01 to 1. The ratio of the protective fluid to the metal may be selected to provide a storage form of the metal, and the ratio may be suitable for the metal electrode of a metal-air battery. The metal may initially be in a solid state including, but not limited to, a configuration including thin pieces of solid metal immersed in a protective fluid. The metal may be stored or delivered to a metal-air battery and heated to melt the metal to form the liquid metal electrode of the battery. Similarly, a configuration is disclosed in which the metal is directed and cooled as a liquid to solidify before use as the metal electrode of the battery.

[0107] In one aspect, the metal electrode may be floated on top of a denser liquid, for example, to facilitate delivery of the metal to a metal-air battery or to facilitate delivery of the metal to an electrolyte-air electrode subassembly. As shown in FIG. 9, when the metal is floated on top of the protective liquid, it may be held by utilizing buoyancy due to contact with the electrolyte-gas electrode assembly. To charge the battery, the metal may be introduced, for example, as a solid including thin pieces or as a liquid. Since Li metal has a lower density, many of the previously described denser liquids may be used. Heavier silicone oils known as Densiron 68 having a density of about 1.06 g / cm 3 at room temperature (25 ° C. (298 K)), which exceeds the densities of the alkali metals Li, Na, and K, are also known. Non-limiting examples include heavy silicone oils known as Densiron 68 having a density of about 1.06 g / cm 3 at room temperature (25 ° C. (298 K)).

[0108] In yet another embodiment, the protective fluid is selected to have a density intermediate between the density of the solid metal and the density of the liquid metal. Taking solid and liquid sodium metals as an example, in a protective fluid having a density of about 0.94 g / cm 3 ³, the liquid sodium metal will float and the solid sodium metal will sediment. Such liquids include, but are not limited to, silicone oils based on polydimethylsiloxane (PDMS) of various average molecular weights. FIGS. 10A - B show the density of various silicone fluids and their variation with temperature, and the results are reproduced in C. Roberts, A. Graham, M. Nemer, L. Phinney, R. Garcia, and E. Stirrup, “Physical Properties of Low-Molecular Weight Polydimethylsiloxane Fluids,” Sandia Report SAND2017 - 1242, 2017, the content of which is hereby incorporated by reference in its entirety for all purposes. FIGS. 11A - B show the density of a mixture of two silicone fluids and their variation with temperature, and the results are reproduced in C. Roberts, A. Graham, M. Nemer, L. Phinney, R. Garcia, and E. Stirrup, “Physical Properties of Low-Molecular Weight Polydimethylsiloxane Fluids,” Sandia Report SAND2017 - 1242, 2017, the content of which is hereby incorporated by reference in its entirety for all purposes. The variation of density with temperature (the slope of the line) is almost the same for all fluids. Near the melting point of sodium metal, about 98 °C (371 K), a high-density silicone fluid such as Densiron 68 having a density of about 1.06 g / cm 3 ³ at about 25 °C (298 K) and a density of about 0.94 g / cm 3A mixture can be prepared with a lower density silicone fluid having a density of, in which solid sodium metal will deposit and liquid sodium metal will float. Other fluids that can be used in the high density fluid composition for this purpose include perfluorohexyl octane (F6H8), Oxane HD, and silicone oils containing nanosilica particles.

[0109] In one aspect, density variations based on temperature are utilized to safely store or transport reactive metals such as Li, Na, or K by immersing the metal in a non-reactive fluid at a temperature where the metal has a higher density than the fluid. For the purpose of supplying the metal to a battery or fuel cell, the fluid or container may be heated to another temperature where the metal has a lower density than the fluid to float the metal on top of the fluid. A device or system including a container such as that shown in FIG. 9, the fluid, and the metal may be heated and cooled to accomplish these functions. In other aspects, the container may have temperature variations throughout the container as shown in FIG. 12. At one location, the temperature T1 is below the melting point of the metal. At another location of the container, the temperature T2 is above the melting point of the metal. The metal may be stored in the region of temperature T1 where the metal is solid and safely stored below the liquid, and transported to the region of temperature T2 where it melts and floats to the surface. A device or system having this operating principle may include a metal storage and delivery system for handling highly reactive metals such as Li, Na, or K for any purpose including, but not limited to, the battery or fuel cell of the present invention.

[0110] Thermochemical formation of metals used as metal electrodes in batteries or fuel cells The metal of the metal-air battery or fuel cell may be electrolytically produced as previously described or thermochemically produced from a metal salt. In one aspect, the metal salt is a discharge product of the battery or fuel cell. A non-limiting example of a thermochemical method is the decomposition of sodium oxide to metallic sodium. Na2O2 and Na2O are known discharge products of sodium-air batteries. As shown in FIGS. 13A - B, the thermal decomposition of these oxides to sodium metal and oxygen can occur at temperatures and pressures determined using thermodynamic calculations or experiments known to those skilled in the art, 2Na2O2 → 2Na2O + O2 2Na2O → 4Na + O2 and may proceed as such. Such data is available from published reports, and one example is "Analysis of sodium generation by sodium oxide decomposition on corrosion resistant materials: a new approach towards sodium redox water splitting cycle," by R. Kumar, H. Miyaoka, K. Shinzato, and T. Ichikawa, RSC Adv. 2021, 11, 2017, reproduced in FIGS. 13A - B, the content of which is incorporated herein by reference in its entirety for all purposes. For example, at an oxygen pressure and partial pressure of 10 -4 Pascals, the decomposition of Na2O to sodium metal (liquid) and oxygen occurs at approximately 550 °C, and at an oxygen pressure and partial pressure of 10 -2 Pascals, the same decomposition reaction occurs at approximately 675 °C. Additionally, it is known that other sodium salts, such as sodium hydroxide, sodium carbonate, and sodium sulfate, decompose to sodium oxide upon heating. Thus, the sodium salt may be thermally decomposed to sodium metal, and the sodium metal may be used as an electrode of the battery or fuel cell. In one aspect, the sodium salt is a discharge product of the battery or a discharge product of the battery that reacts next to form, without limitation, another sodium salt such as sodium hydroxide, sodium carbonate, sodium bicarbonate, or sodium sulfate.

[0111] As a non-limiting example, the discharge product of the sodium-air battery of the fuel cell may be collected and transported to a container at a temperature and oxygen partial pressure at which sodium oxide decomposes into sodium metal and oxygen. The temperature may range from a relatively low temperature of about 400 °C to a relatively high temperature up to the boiling point of sodium metal, which is about 883 °C at 1 atm, or even higher temperatures, for example up to about 1600 °C maximum. In that example, the sodium metal may be present as a vapor phase, or concentrated as a liquid or solid sodium metal and collected for use. The oxygen partial pressure may range from a low pressure of about 10 -7 Pascals to a higher pressure of up to 100 kPa (1 atm) (10 5 Pascals equal) or 1000 kPa (10 atm). The oxygen partial pressure may be controlled by flowing an inert gas over the sodium salt. The inert gas may include nitrogen, which is advantageous due to its abundance and low cost, and the fact that sodium nitride does not form immediately. The inert gas may also include helium, argon, hydrogen, carbon dioxide, and other gases that do not substantially react with sodium metal at the temperature and pressure of the container.

[0112] The present disclosure further encompasses the following embodiments.

[0113] Embodiment 1: A metal-air battery including a current collector; a metal electrode containing a metal and in contact with the current collector; an air electrode on the metal electrode and on the opposite side of the current collector; a solid electrolyte between the metal electrode and the air electrode; and a discharge product of the metal on the air electrode, wherein the metal-air battery is configured to liberate the discharge product.

[0114] Example 2: The metal-air battery of Embodiment 1, wherein the metal electrode contains a metal, and the metal is an alkali metal, an alkaline earth metal, or a combination thereof.

[0115] Embodiment 3: The metal-air battery according to any one of Embodiments 1 to 2, wherein the metal is sodium.

[0116] Embodiment 4: A metal-air battery according to any one of Embodiments 1 to 3, wherein the solid electrolyte is in the form of a container and the metal is disposed inside the container.

[0117] Embodiment 5: A metal-air battery according to Embodiment 4, wherein the air electrode is disposed outside the container and the discharge product is disposed on the air electrode.

[0118] Embodiment 6: A metal-air battery according to any one of Embodiments 1 to 5, wherein the solid electrolyte is in the form of a tube and the metal is disposed outside the tube.

[0119] Embodiment 7: A metal-air battery according to Embodiment 6, wherein the air electrode is disposed outside the tube and the discharge product is disposed on the air electrode.

[0120] Embodiment 8: A metal-air battery according to Embodiment 7, wherein the tube is configured to receive a fluid, and the discharge product is released when contacted by the fluid.

[0121] Embodiment 9: A metal-air battery according to any one of Embodiments 1 to 8, wherein the metal is a liquid and the metal electrode further includes a protective layer.

[0122] Embodiment 10: A metal-air battery according to any one of Embodiments 6 to 8, wherein the protective layer includes an oil or an ionic liquid.

[0123] Embodiment 11: A metal-air battery according to any one of Embodiments 7 to 8, wherein the oil is a hydrocarbon oil, a silicone oil, or a combination thereof, and the oil has a density of 0.8 to 1.06 g / cm 3 and is used in the metal-air battery.

[0124] Embodiment 12: A system including a battery according to any one of Embodiments 1 to 11, including an electric vehicle.

[0125] Embodiment 13: A system according to Embodiment 12, wherein the vehicle is an electric aircraft.

[0126] Embodiment 14: The electric aircraft, a system according to any one of Embodiments 12 to 13, configured to emit the discharge product.

[0127] Embodiment 15: An electric aircraft system including an electric aircraft and a metal-air battery, the metal-air battery including a current collector; a metal electrode including an alkali metal and in contact with the current collector; an air electrode on the metal electrode and on the opposite side of the current collector; and a solid electrolyte between the metal electrode and the air electrode, the metal-air battery being configured to release the discharge product, and the electric aircraft being configured to emit the discharge product.

[0128] Embodiment 16: A system for collecting a discharge product of a metal-air battery according to any one of Embodiments 1 to 14, wherein the air electrode is configured to receive a fluid and release the discharge product when contacted by the fluid.

[0129] Embodiment 17: The system of Embodiment 16, wherein the fluid includes air, an aqueous fluid, a non-aqueous fluid, or a combination thereof.

[0130] Embodiment 18: A method for converting a metal-air battery discharge product into a metal, the method including providing a discharge product of a metal-air battery; contacting the discharge product with a liquid to form a brine; disposing the brine in an electrolytic cell including a solid electrolyte; and electroplating the metal from the brine to convert the metal-air battery discharge product into a metal.

[0131] Embodiment 19: The method of Embodiment 18, wherein the electroplating attaches the metal to a current collector.

[0132] Embodiment 20: The current collector is the current collector of the metal-air battery, and the metal-air battery includes the current collector; a metal electrode including the metal and in contact with the current collector; an air electrode on the metal electrode and on the opposite side of the current collector; and a solid electrolyte between the metal electrode and the air electrode, the metal-air battery being configured to release the discharge product.

[0133] Embodiment 21: A method according to any one of Embodiments 18 - 19, wherein the solid electrolyte has an ion transference rate of the metal greater than 0.9, preferably 0.95 - 0.999, and the electrodeposited metal has a purity of at least 99.9% based on the total metal content.

[0134] Embodiment 22: A method for collecting discharge products of a metal - air battery, the method comprising: providing a metal - air battery configured to liberate discharge products; flushing the air electrode of the metal - air battery with a gas stream to remove the discharge products from the air electrode and provide a gas stream incorporating the discharge products, or flushing the air electrode of the metal - air battery with a liquid to remove the discharge products from the air electrode and provide a solution containing the discharge products, and collecting the discharge products.

[0135] Embodiment 23: The method of Embodiment 22, wherein the gas stream contains a gas inert to the discharge products.

[0136] Embodiment 24: The method of Embodiment 23, wherein the gas contains nitrogen, argon, helium, hydrogen, or a combination thereof.

[0137] Embodiment 25: The method according to any one of Embodiments 22 - 23, wherein the gas stream contains a gas reactive with the discharge products.

[0138] Embodiment 26: The method of Embodiment 25, wherein the gas contains water, carbon monoxide, carbon dioxide, or a combination thereof.

[0139] Embodiment 27: The method according to any one of Embodiments 22 - 26, further comprising contacting the discharge products on the air electrode with water, an aqueous solution, or a non - aqueous solution to provide a solution containing the discharge products.

[0140] Embodiment 28: The method according to any one of Embodiments 22 - 27, further comprising treating the air electrode with a fluid.

[0141] Embodiment 29: The method of Embodiment 28, wherein the fluid contains dry gas.

[0142] Embodiment 30: The method according to any one of Embodiments 22 to 29, further comprising discharging the battery before the flushing, after the flushing, or both before and after the flushing.

[0143] Embodiment 31: The method according to any one of Embodiments 22 to 30, further comprising discharging the battery, wherein the flushing is continuous during the discharging, or further comprising discharging the battery, wherein the flushing is intermittent during the discharging.

[0144] Embodiment 32: The method according to any one of Embodiments 22 to 31, wherein the battery is installed in a device powered by the battery, and the flushing occurs while the battery is installed.

[0145] Embodiment 33: The method according to any one of Embodiments 22 to 32, further comprising removing the battery before the flushing.

[0146] Embodiment 34: The method according to any one of Embodiments 22 to 33, further comprising removing a component including the air electrode of the battery from a device powered by the battery, and flushing the air electrode.

[0147] Embodiment 35: A method for processing discharge products of a metal-air battery, the method comprising: providing discharge products from a metal-air battery; contacting the collected discharge products with water to form a brine containing metal ions of the metal of the metal-air battery; disposing the brine in an electrodeposition cell in contact with a conductive electrolyte; and reducing the metal ions on a current collector to form the metal of the metal-air battery to process the discharge products.

[0148] Embodiment 36: The method of Embodiment 35, wherein the discharge product contains the metal hydroxide, oxide, carbonate, bicarbonate or oxalate of the metal of the metal-air battery, or a combination thereof.

[0149] Embodiment 37: The method according to any one of Embodiments 35 to 36, wherein the brine has a metal ion concentration of 0.01 to 10 moles per liter.

[0150] Embodiment 38: The method according to any one of Embodiments 35 to 37, wherein the electrolyte contains a solid oxide electrolyte, a solid polymer electrolyte, a molten salt, or a combination thereof.

[0151] Embodiment 39: The method according to any one of Embodiments 35 to 38, wherein the metal is electrodeposited between the current collector and the electrolyte.

[0152] Embodiment 40: The method of Embodiment 36, further comprising disposing an air electrode on the electrolyte.

[0153] Embodiment 41: The method according to any one of Embodiments 35 to 40, further comprising converting the discharge product into a halide and electrolytically decomposing the halide to form the metal and the halogen.

[0154] Embodiment 42: The method of Embodiment 41, wherein the metal is lithium, sodium, or a combination thereof, and the halogen is chlorine.

[0155] Embodiment 43: The method of Embodiment 42, wherein the halide is lithium chloride, sodium chloride, or a combination thereof.

[0156] Embodiment 44: A method for manufacturing a metal-air battery, the method including collecting discharge products from the metal-air battery; contacting the collected discharge products with water to form a brine containing metal ions of the metal of the metal-air battery; disposing the brine in an electrodeposition cell in contact with a conductive electrolyte for the metal ions; reducing the metal ions on a current collector to form the metal of the metal-air battery on the current collector; and disposing an air electrode on the electrolyte to manufacture the metal-air battery, wherein the collecting includes a method for collecting the discharge products of any one of Embodiments 22 to 35 of the metal-air battery.

[0157] Embodiment 45: A method for manufacturing a battery, the method including collecting discharge products from a metal-air battery; contacting the collected discharge products with water to form a brine containing metal ions of the metal of the battery; disposing the brine in an electrodeposition cell in contact with a conductive electrolyte for the metal ions; reducing the metal ions on a current collector to form the metal of the battery on the current collector; and disposing an electrode containing an intercalation compound on the electrolyte to manufacture the battery.

[0158] Embodiment 46: The method of Embodiment 45, wherein the collecting includes a method for collecting the discharge products of any one of Embodiments 22 to 35 of the metal-air battery.

[0159] Embodiment 47: The method according to any one of Embodiments 45 to 46, wherein the intercalation compound is an oxide, a phosphate, carbon, or a combination thereof.

[0160] Embodiment 48: The method of Embodiment 47, wherein the intercalation compound includes graphite, hard carbon, silicon, or a combination thereof, and the electrode is a negative electrode for a lithium battery.

[0161] Embodiment 49: A method for manufacturing a metal-air battery, the method comprising: providing a current collector; disposing a precursor of the solid electrolyte on the current collector; treating the precursor to form the solid electrolyte; contacting the solid electrolyte with a liquid containing metal ions of the metal of the metal-air battery; reducing the metal ions to electrodeposit the metal on the current collector; and disposing an air electrode on the electrolyte to manufacture the metal-air battery.

[0162] Embodiment 50: The method of Embodiment 49, wherein the precursor comprises a metal nitrate, sulfate, carbonate, oxalate, acetate, alkoxide, or a combination thereof.

[0163] Embodiment 51: The method according to any one of Embodiments 49 to 50, wherein the treating comprises irradiating with radiation having a wavelength in the range from microwaves to gamma rays.

[0164] Embodiment 52: The method according to any one of Embodiments 49 to 51, further comprising irradiating the solid electrolyte to densify the solid electrolyte.

[0165] Embodiment 53: The method according to any one of Embodiments 50, wherein the densifying comprises irradiating with radiation having a wavelength in the range from microwaves to gamma rays.

[0166] Embodiment 54: The method according to any one of Embodiments 49 to 53, wherein the liquid containing metal ions is aqueous or non-aqueous.

[0167] Embodiment 55: The method according to any one of Embodiments 53 to 54, wherein the liquid is an aqueous metal salt solution.

[0168] Embodiment 56: The method according to any one of Embodiments 53 to 55, wherein the liquid is an ionic liquid, a molten metal salt, or a combination thereof.

[0169] Embodiment 57: The method according to any one of Embodiments 49 to 56, wherein the metal ions comprise alkali metal ions, alkaline earth metal ions, or a combination thereof.

[0170] Embodiment 58: The method according to any one of Embodiments 56 to 57, wherein the metal ion is a sodium ion and the metal is sodium.

[0171] Embodiment 59: The method according to any one of Embodiments 56 to 58, further comprising removing the current collector from the device for electrodepositing the metal together with the metal and the solid electrolyte after the reduction.

[0172] Embodiment 60: A method for manufacturing a metal-air battery, the method comprising providing a current collector; disposing a solid electrolyte on the current collector; irradiating the solid electrolyte to densify the solid electrolyte; contacting the solid electrolyte with a liquid containing metal ions of the metal of the metal-air battery; reducing the metal ions to electrodeposit the metal on the current collector; and disposing an air electrode on the electrolyte to manufacture the metal-air battery.

[0173] Embodiment 61: An electric vehicle including the metal-air battery according to any one of Embodiments 1 to 60, or a method for manufacturing the metal-air battery.

[0174] Embodiment 62: The electric vehicle according to any one of Embodiments 1 to 61, wherein the electric vehicle is an aircraft.

[0175] Embodiment 63: The electric vehicle according to any one of Embodiments 1 to 62, wherein when the vehicle is propelled, the discharge product is released from the vehicle.

[0176] Embodiment 64: The electric vehicle according to Embodiment 63, wherein the discharge product is flushed from the air electrode by a gas stream containing air.

[0177] Embodiment 65: A method for carbon isolation, the method comprising operating an electric vehicle according to any one of Embodiments 1 to 64; forming a discharge product by bringing the air electrode into contact with air, the air electrode containing carbon dioxide and the discharge product containing carbonate, bicarbonate, or a combination thereof; and discharging the discharge product to isolate the carbon.

[0178] Embodiment 66: The electric vehicle according to Embodiment 65, wherein the metal-air battery is a sodium-air battery and the discharge product is sodium carbonate, sodium bicarbonate, or a combination thereof.

[0179] Embodiment 67: A system comprising an electrolytic cell for electrolytically generating a metal and a metal-air battery containing the metal, the system comprising a metal-air battery including a current collector, a metal electrode containing the metal and in contact with the current collector, an air electrode on the metal electrode, and a first solid electrolyte between the metal electrode and the air electrode; and an electrolytic cell including a brine container configured to contain a brine containing metal ions of the metal, a second solid electrolyte between the brine container and the metal electrode of the metal-air battery, a cathode of the electrolytic cell on a side of the second solid electrolyte opposite the brine container, and an anode of the electrolytic cell in contact in the brine container and on a side of the second solid electrolyte opposite the brine container.

[0180] Embodiment 68: The system according to Embodiment 67, wherein the metal is sodium and the metal electrode further includes a protective layer, and the protective layer is an oil having a density of 0.8 to 1.06 g / cm 3 of the system.

[0181] Embodiment 69: A method for electrolytically producing a metal and for using the metal in a metal-air battery, the method comprising: a metal-air battery including a current collector, a metal electrode containing a metal and in contact with the current collector, an air electrode on the metal electrode, and a first solid electrolyte between the metal electrode and the air electrode; an electrolytic cell including a brine contained in a brine container and containing metal ions of the metal, a second solid electrolyte between the brine and the metal electrode of the metal-air battery, a cathode of the electrolytic cell on a side of the second solid electrolyte opposite the brine container, and an anode of the electrolytic cell in contact in the brine and on an opposite side of the second solid electrolyte; providing a voltage between the cathode of the electrolytic cell and the anode of the electrolytic cell to transport metal ions from the brine and form the metal of the metal ions on the cathode of the electrolytic cell; and contacting the air electrode with air to convert the metal on the cathode and in the metal-air battery into discharge products and use the metal.

[0182] Embodiment 70: A method of charging a metal-air battery, the method comprising providing a metal-air battery including a solid electrolyte between an air electrode and a metal electrode and a protective fluid on the metal electrode and opposite the solid electrolyte, the protective fluid and the metal electrode being contained in a container having an upper inlet and a lower inlet; and adding the metal through at least one of the upper inlet or the lower inlet to charge the metal-air battery.

[0183] Embodiment 71: The method of Embodiment 70, wherein the metal is sodium and the protective fluid is oil.

[0184] Embodiment 72: The method of Embodiment 71, further comprising providing sodium oxide, heating the sodium oxide in a vacuum to convert the sodium oxide into sodium and oxygen, and directing the sodium towards the metal-air battery to provide the sodium.

[0185] Embodiment 73: A method of operating a metal-air battery, the method comprising providing a metal-air battery including a solid electrolyte between an air electrode and a metal electrode and a protective fluid on the metal electrode on the opposite side of the solid electrolyte, the protective fluid and the metal electrode being contained within a container having an upper inlet and a lower inlet; and operating the metal-air battery by heating the metal to float the metal on the protective fluid or by cooling the metal to deposit the metal in the protective fluid.

[0186] Embodiment 74: The method of Embodiment 73, wherein the metal is sodium and the protective fluid is oil.

[0187] Embodiment 75: A system configured to thermochemically produce a metal, the system including a metal salt including a discharge product of a metal-air battery and a container configured to control pressure, temperature, atmosphere, or a combination thereof, the container including an inlet, an outlet, or both.

[0188] Embodiment 76: The system of Embodiment 75, wherein the metal salt is a sodium salt including sodium hydroxide, sodium carbonate, sodium bicarbonate, sodium sulfate, sodium oxide, or a combination thereof.

[0189] Embodiment 77: The system according to any one of Embodiments 75 to 76, further including the metal of the metal salt, the metal being a thermochemically produced product of the metal salt.

[0190] Embodiment 78: A method of thermochemically producing a metal, the method including providing a metal salt; providing a container configured to control pressure, temperature, atmosphere, or a combination thereof, the container including an inlet, an outlet, or both; disposing the metal salt within the container; and controlling the pressure, the temperature, the atmosphere, or a combination thereof to thermochemically decompose the metal salt to produce the metal.

[0191] Embodiment 79: The method of Embodiment 78, further comprising disposing the metal on a current collector to provide a metal electrode subassembly.

[0192] Embodiment 80: The method according to any one of Embodiments 78 to 79, wherein the metal salt is a sodium salt containing sodium hydroxide, sodium carbonate, sodium bicarbonate, sodium sulfate, sodium oxide, or a combination thereof, and the metal is sodium.

[0193] Embodiment 81: The method according to any one of Embodiments 78 to 80, wherein the pressure is an oxygen partial pressure, and the oxygen partial pressure is 10 -7 ~10 5 Pascals.

[0194] Embodiment 82: The method according to any one of Embodiments 78 to 81, wherein the temperature is 400 °C to 1600 °C.

[0195] Embodiment 83: The method according to any one of Embodiments 78 to 82, wherein the atmosphere contains an inert gas, and the inert gas is transported through the inlet, the outlet, or both.

[0196] Embodiment 84: The method of Embodiment 83, wherein the inert gas contains helium, argon, hydrogen, carbon dioxide, or a combination thereof.

[0197] The compositions, methods, and articles can alternatively include, consist of, or consist essentially of any suitable materials, steps, or components disclosed herein. The compositions, methods, and articles can be formulated to lack, or substantially not include, any materials (or species), steps, or components that are otherwise not necessary to achieve the functions or purposes of the compositions, methods, and articles.

[0198] All ranges disclosed in this specification, including their endpoints, are combinable independently of each other (e.g., "up to 25 wt%", or more specifically, the range of 5 wt% to 20 wt% includes its endpoints and all intermediate values in the range of 5 wt% to 25 wt%, etc.). "Combination" includes blends, mixtures, alloys, reaction products, and the like. The terms "first", "second", and the like do not denote any order, quantity, or importance, but are used rather to distinguish one element from another. The terms "a", "an", and "the" do not denote a limitation of quantity and must be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by the context. "Or" means "and / or" unless otherwise explicitly stated. References to "some embodiments", "one embodiment", etc. throughout this specification mean that a particular element described in connection with the embodiment is included in at least one embodiment described herein, and may or may not be present in other embodiments. Additionally, it should be understood that the described elements may be combined in any suitable manner in various embodiments. "Their combinations" are open-ended and include any combination that includes at least one of the recited components or characteristics, optionally together with similar or equivalent components or characteristics not recited.

[0199] When an element is referred to as being "on" another element, it will be understood that it can be directly on the other element or intervening elements may be present therebetween. In contrast, when an element is referred to as being "directly on" another element, no intervening elements are present.

[0200] Furthermore, relative terms such as "lower" or "bottom" and "upper" or "topmost" may be used herein to describe the relationship of one element shown in the figures to another element. It will be understood that relative terms are intended to encompass different orientations of the device in addition to the orientation shown in the figures. For example, if one device in the figure is rotated, an element described as being on the "lower" side of another element will be oriented on the "upper" side of the other element. Therefore, the term "lower" may encompass both "lower" and "upper" orientations depending on the particular orientation of the figure. Similarly, if one device in the figure is rotated, an element described as "lower" or "beneath" another element will be oriented above the other element. Therefore, the terms "lower" or "beneath" encompass both upper and lower orientations.

[0201] Unless otherwise specified herein to the contrary, all test standards are the most recent substantive standards as of the filing date of this application, or if priority is claimed, as of the filing date of the earlier priority application in which the test standard appears.

[0202] Unless otherwise defined, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. All cited patents, patent applications, and other references are hereby incorporated by reference in their entirety. However, if terms in this application conflict or are inconsistent with terms in the incorporated references, the terms in this application shall control over the conflicting terms in the incorporated references.

[0203] Although specific embodiments have been described, alternatives, improvements, variations, modifications, and substantial equivalents that are not presently contemplated or that may not be presently contemplated may be devised by the applicant or other persons of ordinary skill in the art. Accordingly, the appended claims, which may be amended, are intended to cover all such alternatives, improvements, variations, modifications, and substantial equivalents.

Claims

1. A current collector; A metal electrode containing a metal and contacting the current collector; An air electrode on the metal electrode and on the opposite side of the current collector; A solid electrolyte between the metal electrode and the air electrode; The discharge product of the metal on the air electrode, A metal-air battery comprising, The metal-air battery is configured to release the discharge product, Metal-air battery.

2. The metal-air battery according to claim 1, wherein the metal electrode contains a metal, and the metal is an alkali metal, an alkaline earth metal, or a combination thereof.

3. The metal-air battery according to claim 1, wherein the metal is sodium.

4. The metal-air battery according to claim 1, wherein the solid electrolyte is in the form of a container, and the metal is disposed inside the container.

5. The metal-air battery according to claim 4, wherein the air electrode is disposed outside the container, and the discharge product is disposed on the air electrode.

6. The metal-air battery according to claim 1, wherein the solid electrolyte is in the form of a tube, and the metal is disposed outside the tube.

7. The metal-air battery according to claim 6, wherein the air electrode is disposed outside the tube, and the discharge product is disposed on the air electrode.

8. The metal-air battery according to claim 7, wherein the tube is configured to receive a fluid, and the discharge product is released when contacted by the fluid.

9. The metal-air battery according to claim 1, wherein the metal is a liquid, a solid, or both, and the metal electrode further includes a protective layer.

10. The metal-air battery according to claim 6, wherein the protective layer includes an oil, an ionic liquid, a liquid substantially non-reactive with the metal, or a combination thereof.

11. The oil is a hydrocarbon oil, a silicone oil, or a combination thereof, and the oil has a density of 0.8 to 1.06 g / cm ３ The metal-air battery according to claim 7.

12. A system including the metal-air battery according to claim 1, including an electric vehicle.

13. The system according to claim 12, wherein the electric vehicle is a ground vehicle, an aircraft, or a water vehicle.

14. The system according to claim 12, wherein the electric aircraft is configured to release the discharge product.

15. An electric aircraft; A metal-air battery; An electric aircraft system comprising, The metal-air battery comprising, A current collector; A metal electrode containing an alkali metal and contacting the current collector; An air electrode on the metal electrode and on the opposite side of the current collector; A solid electrolyte between the metal electrode and the air electrode, Comprising, The metal-air battery is configured to release the discharge product, The electric aircraft is configured to discharge the discharge product, An electric aircraft system.

16. The system for collecting the discharge product of the metal-air battery according to claim 1, wherein the air electrode is configured to receive a fluid and release the discharge product when contacted by the fluid.

17. The system according to claim 16, wherein the fluid includes a gas, an aqueous fluid, a non-aqueous fluid, or a combination thereof.

18. A method for converting a metal-air battery discharge product into a metal, the method comprising: Providing a discharge product of a metal-air battery; Contacting the discharge product with a liquid to form a brine; Placing the brine in an electrolytic cell containing a solid electrolyte; Electrodepositing the metal from the brine to convert the metal-air battery discharge product into a metal, or Providing the discharge product of the metal-air battery; Converting the discharge product into a metal salt; Placing the metal salt in the electrolytic cell containing the solid electrolyte; Electrodepositing the metal from the metal salt to convert the metal salt into a metal, The method includes.

19. The method according to claim 18, wherein the electrodeposition attaches the metal to a current collector.

20. The current collector is the current collector of the metal-air battery, and the metal-air battery includes: The current collector; A metal electrode containing the metal and in contact with the current collector; An air electrode on the metal electrode and on the opposite side of the current collector; A solid electrolyte between the metal electrode and the air electrode, Including, The metal-air battery is configured to release the discharge product, The method according to claim 19.

21. The method according to claim 18, wherein the solid electrolyte has an ion transport rate of the metal greater than 0.9, preferably 0.95 to 0.999, and the electrodeposited metal has a purity of at least 90% based on the total metal content.

22. A method for collecting the discharge product of a metal-air battery, the method comprising: Providing a metal-air battery configured to release the discharge product; Flushing the air electrode of the metal-air battery with a gas stream to remove the discharge product from the air electrode and provide a gas stream incorporating the discharge product, or flushing the air electrode of the metal-air battery with a liquid to remove the discharge product from the air electrode and provide a solution containing the discharge product, and collecting the discharge product. A method comprising the above.

23. The method according to claim 22, wherein the gas stream contains a gas inert to the discharge product.

24. The method according to claim 23, wherein the gas contains nitrogen, argon, helium, hydrogen, or a combination thereof.

25. The method according to claim 22, wherein the gas stream contains a gas reactive to the discharge product.

26. The method according to claim 25, wherein the gas contains oxygen, water, carbon monoxide, carbon dioxide, or a combination thereof.

27. The method according to claim 22, further comprising contacting the discharge product on the air electrode with water, an aqueous solution, or a non-aqueous solution to provide a solution containing the discharge product.

28. The method according to claim 22, further comprising treating the air electrode with a fluid.

29. The method according to claim 28, wherein the fluid contains a dry gas.

30. The method according to claim 22, further comprising discharging the battery before the flushing, after the flushing, or both before and after the flushing.

31. The method according to claim 22, further comprising discharging the battery, wherein the flushing is continuous during the discharge, or further comprising discharging the battery, wherein the flushing is intermittent during the discharge.

32. The method according to claim 22, wherein the battery is installed in a device powered by the battery, and the flushing occurs while the battery is installed.

33. The method according to claim 22, further comprising removing the battery before the flushing.

34. The method according to claim ២២, further comprising removing a component including the air electrode of the battery from a device powered by the battery, and flushing the air electrode.

35. A method for processing the discharge product of a metal-air battery, the method comprising: Providing a discharge product from a metal-air battery; Contacting the collected discharge product with water to form a brine containing metal ions of the metal of the metal-air battery; Placing the brine in an electrodeposition cell in contact with a conductive electrolyte for the metal ions; and Reducing the metal ions on a current collector to form the metal of the metal-air battery and processing the discharge product, A method comprising.

36. The method according to claim 35, wherein the discharge product comprises a hydroxide, oxide, carbonate, bicarbonate or oxalate of the metal of the metal-air battery, or a combination thereof.

37. The method according to claim 35, wherein the brine has a metal ion concentration of 0.01 to 10 moles per liter.

38. The method according to claim 35, wherein the electrolyte comprises a solid oxide electrolyte, a solid polymer electrolyte, a molten salt, or a combination thereof.

39. The method according to claim 35, wherein the metal is electrodeposited between the current collector and the electrolyte.

40. The method according to claim 36, further comprising disposing an air electrode on the electrolyte.

41. Converting the discharge product to a halide, and Electrically decomposing the halide to form the metal and the halogen, The method according to claim 35, further comprising.

42. The method according to claim 41, wherein the metal comprises lithium, sodium, or a combination thereof, and the halogen is chlorine.

43. The method according to claim 42, wherein the halide is lithium chloride, sodium chloride, or a combination thereof.

44. A method for manufacturing a metal-air battery, the method comprising: Collecting a discharge product from a metal-air battery; Contacting the collected discharge product with water to form a brine containing metal ions of the metal of the metal-air battery; Placing the brine in an electrodeposition cell in contact with a conductive electrolyte for the metal ions; Reducing the metal ions on a current collector to form the metal of the metal-air battery on the current collector; and Disposing an air electrode on the electrolyte to manufacture the metal-air battery, Including, Said collecting comprises the method of collecting the discharge product of the metal-air battery according to claim 22, or Collecting the discharge product from the metal-air battery; Converting the discharge product to a metal salt; placing the metal salt in the electrodeposition cell in contact with a conductive electrolyte for the metal ions; reducing the metal ions on the current collector to form the metal of the metal-air battery on the current collector; and placing the air electrode on the electrolyte to manufacture the metal-air battery, wherein the collecting includes the method of collecting the discharge products of the metal-air battery according to claim 22, method.

45. A method for manufacturing a battery, the method comprising: collecting discharge products from a metal-air battery; contacting the collected discharge products with water to form a brine containing metal ions of the metal of the battery; placing the brine in an electrodeposition cell in contact with a conductive electrolyte for the metal ions; reducing the metal ions on the current collector to form the metal of the battery on the current collector; and placing an electrode containing an intercalation compound on the electrolyte to manufacture the battery, comprising, or collecting the discharge products from the metal-air battery; converting the discharge products into a metal salt; placing the metal salt in the electrodeposition cell in contact with a conductive electrolyte for the metal ions; reducing the metal ions on the current collector to form the metal of the battery on the current collector; and placing the electrode containing the intercalation compound on the electrolyte to manufacture the battery, comprising, method.

46. The method according to claim 45, wherein the collecting includes the method of collecting the discharge products of the metal-air battery according to claim 22.

47. The method according to claim 45, wherein the intercalation compound is an oxide, a phosphate, carbon, or a combination thereof.

48. The method according to claim 47, wherein the intercalation compound includes graphite, hard carbon, silicon, or a combination thereof, and the electrode is a negative electrode for a lithium or sodium battery.

49. A method for manufacturing a metal-air battery, the method comprising: providing a current collector; placing a precursor of the solid electrolyte on the current collector; treating the precursor to form the solid electrolyte; contacting the solid electrolyte with a source of metal ions of the metal of the metal-air battery; reducing the metal ions to electrodeposit the metal on the current collector; and Manufacturing the metal-air battery by disposing an air electrode on the electrolyte, A method comprising.

50. The method according to claim 49, wherein the precursor comprises a metal nitrate, sulfate, carbonate, oxalate, acetate, alkoxide, or a combination thereof.

51. The method according to claim 49, wherein the treating comprises heating, irradiation with radiation having a wavelength in the range from microwave to gamma ray, or a combination thereof.

52. The method according to claim 49, further comprising densifying the solid electrolyte by heating, irradiating the solid electrolyte with radiation having a wavelength in the range from microwave to gamma ray, or a combination thereof.

53. The method according to claim 50, wherein the densifying comprises irradiation with radiation having a wavelength in the range from microwave to gamma ray.

54. The method according to claim 49, wherein the liquid containing metal ions is aqueous or non-aqueous.

55. The method according to claim 54, wherein the liquid is an aqueous metal salt solution.

56. The method according to claim 54, wherein the liquid is an ionic liquid, a molten metal salt, or a combination thereof.

57. The method according to claim 49, wherein the metal ions comprise alkali metal ions, alkaline earth metal ions, or a combination thereof.

58. The method according to claim 56, wherein the metal ions are sodium ions and the metal is sodium.

59. The method according to claim 56, further comprising removing the current collector together with the metal and the solid electrolyte from a device for electrodepositing the metal after the reduction.

60. A method for manufacturing a metal-air battery, the method comprising: Providing a current collector; Disposing a solid electrolyte on the current collector; Irradiating the solid electrolyte to densify the solid electrolyte; Contacting the solid electrolyte with a liquid containing metal ions of the metal of the metal-air battery; Reducing the metal ions to electrodeposit the metal on the current collector; and Manufacturing the metal-air battery by disposing an air electrode on the electrolyte, A method comprising.

61. An electric vehicle comprising the metal-air battery according to claim 1.

62. The electric vehicle according to claim 61, wherein the electric vehicle is an aircraft.

63. The electric vehicle according to claim 61, wherein when the vehicle is propelled, the discharge product is released from the vehicle.

64. The electric vehicle according to claim 63, wherein the discharge product is flushed from the air electrode by a gas stream containing air.

65. A method of carbon isolation, the method comprising: operating the electric vehicle according to claim 61; forming the discharge product by contacting the air electrode with air, wherein the air electrode contains carbon dioxide and the discharge product contains carbonate, bicarbonate, or a combination thereof; and releasing the discharge product to isolate the carbon. A method comprising the above.

66. The electric vehicle according to claim 65, wherein the metal-air battery is a sodium-air battery, and the discharge product contains sodium oxide, sodium hydroxide, sodium carbonate, sodium bicarbonate, or a combination thereof.

67. A system comprising an electrolytic cell for electrolytically producing a metal and a metal-air battery containing the metal, the system comprising: a metal-air battery, a current collector, a metal electrode containing a metal and in contact with the current collector, an air electrode on the metal electrode, a first solid electrolyte between the metal electrode and the air electrode; a metal-air battery comprising the above; an electrolytic cell, a container configured to contain a metal ion source containing metal ions of the metal, a second solid electrolyte between the container and the metal electrode of the metal-air battery, a cathode of the electrolytic cell on the side of the second solid electrolyte opposite the container, an anode of the electrolytic cell in contact in the container and on the opposite side of the second solid electrolyte; an electrolytic cell comprising the above; a system comprising the above.

68. The metal is sodium, and the metal electrode further includes a protective layer, and the protective layer is an oil having a density of 0.8 to 1.06 g / cm ３ The system according to claim 67, which is an oil having a density of.

69. A method for electrolytically producing a metal and for using the metal in a metal-air battery, the method comprising: a metal-air battery, a current collector, a metal electrode containing a metal and in contact with the current collector, an air electrode on the metal electrode, a first solid electrolyte between the metal electrode and the air electrode; a metal-air battery comprising the above; an electrolytic cell, a container configured to contain a metal ion source containing metal ions of the metal, a second solid electrolyte between the container and the metal electrode of the metal-air battery, a cathode of the electrolytic cell on the side of the second solid electrolyte opposite the container, the anode of the electrolytic cell in contact in the container and on the opposite side of the second solid electrolyte; an electrolytic cell comprising; providing a system comprising; providing a voltage between the cathode and the anode of the electrolytic cell to transport metal ions from the brine and form the metal of the metal ions on the cathode of the electrolytic cell; and contacting the air electrode with air to convert the metal on the cathode and in the air cell into a discharge product for using the metal, a method comprising.

70. A method of charging a metal-air battery, the method comprising: a solid electrolyte between an air electrode and a metal electrode; a protective fluid on the metal electrode and on the opposite side of the solid electrolyte; providing a metal-air battery comprising, wherein the protective fluid and the metal electrode are contained in a container having an upper inlet and a lower inlet; providing a metal-air battery; and adding the metal through at least one of the upper inlet or the lower inlet to charge the metal-air battery, a method comprising.

71. The method according to claim 70, wherein the metal is sodium and the protective fluid is oil.

72. providing sodium hydroxide, sodium carbonate, sodium bicarbonate, sodium sulfate, sodium oxide, or a combination thereof; heating the sodium hydroxide, sodium carbonate, sodium bicarbonate, sodium sulfate, sodium oxide, or a combination thereof in a vacuum to convert the sodium oxide into sodium and a gas comprising oxygen, carbon dioxide, sulfur dioxide, water, or a combination thereof; and directing the sodium towards the metal-air battery to provide the sodium, the method according to claim 71, further comprising providing the sodium thereby.

73. A method of operating a metal-air battery, the method comprising: a solid electrolyte between an air electrode and a metal electrode; a protective fluid on the metal electrode and on the opposite side of the solid electrolyte; providing a metal-air battery comprising, wherein the protective fluid and the metal electrode are contained in a container having an upper inlet and a lower inlet; providing a metal-air battery; and heating the metal to float the metal on the protective fluid or cooling the metal to deposit the metal in the protective fluid to operate the metal-air battery, A method comprising...

74. The method according to claim 73, wherein the metal is sodium and the protective fluid is oil.

75. A system configured to thermochemically produce a metal, the system comprising: A metal salt containing a discharge product of a metal-air battery; A container configured to control pressure, temperature, atmosphere, or a combination thereof, the container including an inlet, an outlet, or both. Including The container includes an inlet, an outlet, or both. System

76. The system according to claim 75, wherein the metal salt is a sodium salt including sodium hydroxide, sodium carbonate, sodium bicarbonate, sodium sulfate, sodium oxide, or a combination thereof.

77. The system according to claim 75, further including the metal of the metal salt, the metal being a product thermochemically produced from the metal salt.

78. A method for thermochemically producing a metal, the method comprising: Providing a metal salt; Providing a container configured to control pressure, temperature, atmosphere, or a combination thereof, the container including an inlet, an outlet, or both; Placing the metal salt in the container; Controlling the pressure, the temperature, the atmosphere, or a combination thereof to thermochemically decompose the metal salt to produce the metal. Including

79. The method according to claim 78, further including placing the metal on a current collector to provide a metal electrode subassembly.

80. The method according to claim 78, wherein the metal salt is a sodium salt including sodium hydroxide, sodium carbonate, sodium bicarbonate, sodium sulfate, sodium oxide, or a combination thereof, and the metal is sodium.

81. The pressure is an oxygen partial pressure, and the oxygen partial pressure is 10 －７ to 10 ５ Pascals, the method according to claim 78.

82. The method according to claim 78, wherein the temperature is from 400°C to 1600°C.

83. The method according to claim 78, wherein the atmosphere includes an inert gas, and the inert gas is transported through the inlet, the outlet, or both.

84. The method according to claim 83, wherein the inert gas includes nitrogen, helium, argon, hydrogen, carbon dioxide, or a combination thereof.

85. The metal-air battery according to claim 1, wherein the air electrode is in contact with a second current collector.

86. The system according to claim 12, wherein the electric vehicle is a car, a truck, a train, a helicopter, an unmanned aerial vehicle, a drone, an airplane, a vertical takeoff and landing aircraft (VTOL), a craft, a boat, a ship, a barge, or a tugboat.

87. The metal-air battery according to claim 15, wherein the air electrode is in contact with a second current collector.

88. wherein the gas is air, nitrogen, CO ２ , or a combination thereof, the system according to claim 17.

89. The method according to claim 18, wherein the metal salt comprises a metal halide, a metal sulfide, or a combination thereof.

90. The method according to claim 89, wherein the metal salt is further converted into NASICON, Na-beta''-alumina, or both.

91. The method according to claim 20, wherein the air electrode is in contact with a second current collector.

92. A method for processing discharge products of a metal-air battery, the method comprising: providing discharge products from a metal-air battery; contacting the collected discharge products with water to form a brine containing metal ions of the metal of the metal-air battery; converting the brine to produce a metal hydroxide, a metal carbonate, a metal bicarbonate, a metal halide, or a combination thereof. A method comprising the above.

93. The metal hydroxide or metal carbonate is LiOH, Li ２ CO ３ , NaOH, or Na ２ CO ３ The method according to claim 92, comprising.

94. The method according to claim 92, further comprising converting the metal hydroxide, the metal carbonate, the metal bicarbonate, the metal halide to produce a battery electrode compound or a solid electrolyte.

95. wherein the metal halide is LiF and is converted to LiPF ６ The method according to claim 94, wherein the method is converted to

96. The method according to claim 49, wherein the source comprises a liquid, a solid, or a vapor.

97. The method according to claim 96, wherein the liquid comprises a brine, a molten metal halide, a molten metal sulfide, or a combination thereof.

98. The electric vehicle according to claim 61, wherein the discharge products are removed from the air electrode and optionally stored in a container as a solid or a liquid.

99. The electrolytic cell comprises: a brine container configured to contain a brine containing metal ions of the metal; a second solid electrolyte between the brine container and the metal electrode of the metal-air battery; a cathode of the electrolytic cell on the side of the second solid electrolyte opposite to the brine container; an anode of the electrolytic cell in contact within the brine container and on the opposite side of the second solid electrolyte. The system according to claim 67, further comprising the above.

100. The system according to claim 67, wherein the metal ion source comprises a metal chloride, a metal sulfide, or a combination thereof.

101. The system according to claim 69, wherein the metal ion source comprises a metal chloride, a metal sulfide, or a combination thereof.

102. A combined system comprising the system according to claim 1, the system according to claim 67, the system according to claim 69, the system according to claim 75, or a combination thereof.

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