Patent Application
20230318040
The present disclosure is directed to an aluminum-ether-based composition for use in batteries and aluminum deposition.
Aluminum coating, widespread in industrial processes, has been widely adopted as a surface protection methodology for steel and alloys used for automotive and aerospace applications to provide chemical resiliency against marine and other corrosive environments encountered in the oil, gas, materials, and agricultural industries. Aluminum coating, however, is mainly conducted using hot-dip processes involving molten aluminum and/or electrodeposition from molten salts. These processes face serious problems and drawbacks concerning the environment and energy cost. And, in recent years, electrolyte solutions of AlCl3 also have found use in rechargeable batteries; however, most electrolyte-driven deposition is based on AlCl3-LiAH4-diethyl ether baths (the NBS baths) and the ionic liquid-based baths. These solutions suffer from high hygroscopicity and high cost of raw materials. There exists a need in the art for a new composition suitable for aluminum deposition and/or that can serve as an electrolyte for use in aluminum-based electrode systems.
Disclosed herein are aspects of an aluminum-ether-based composition for use in electroplating an aluminum metal coating or for use in an aluminum battery, comprising: an aluminum salt component having a structure according to a formula AlX3, wherein each X independently is a halogen atom; and an ether-based solvent having a structure according to a formula R1—O—R2, wherein each of R1 and R2 independently is selected from C3-20alkyl, C3-20alkenyl, C3-20alkynyl, C3-20haloalkyl, C3-20haloalkenyl, or C3-20haloalkynyl; wherein the aluminum salt component and the ether-based solvent are present in amounts that provide a molar ratio of 0.01 to 1.5 (aluminum salt component:ether-based solvent) and the aluminum-ether-based composition does not comprise, or is free of, a metal hydride and/or an ionic liquid.
In any or all of the above aspects of the disclosure, the aluminum-ether-based composition further comprises a rare earth element component having a formula REE(Z)n, wherein: REE is selected from lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), scandium (Sc), yttrium (Y), or combinations thereof; each Z independently is selected from a halogen; a polyatomic anion; an alkoxy group having a formula R3O—, wherein R3 is selected from an aliphatic group, an aromatic group, a haloaliphatic group, or a combination thereof; or a combination thereof; and n is an integer selected from 3 or 4.
Also disclosed herein are aspects of a method, comprising applying a voltage to a system comprising an aluminum-containing substrate, a second substrate, and the aluminum-ether-based composition according to any or all of the above aspects of the disclosure, wherein the aluminum-containing substrate and the second substrate are positioned at a distance from one another, and the aluminum-ether-based composition comes into fluid contact with both the aluminum-containing substrate and the second substrate.
The foregoing and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures.
Overview of Terms
The following explanations of terms and abbreviations are provided to better describe the present disclosure and to guide those of ordinary skill in the art in the practice of the present disclosure. As used herein, “comprising” means “including” and the singular forms “a” or “an” or “the” include plural references unless the context clearly dictates otherwise. The term “or” refers to a single element of stated alternative elements or a combination of two or more elements, unless the context clearly indicates otherwise.
Unless explained otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this disclosure belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present disclosure, suitable methods and materials are described below. The materials, methods, and examples are illustrative only and not intended to be limiting. Other features of the disclosure are apparent from the following detailed description and the claims.
Unless otherwise indicated, all numbers expressing quantities of components, molecular weights, molarities, voltages, capacities, and so forth, as used in the specification or claims are to be understood as being modified by the term “about.” Accordingly, unless otherwise implicitly or explicitly indicated, or unless the context is properly understood by a person of ordinary skill in the art to have a more definitive construction, the numerical parameters set forth are approximations that may depend on the desired properties sought and/or limits of detection under standard test conditions/methods as known to those of ordinary skill in the art. When directly and explicitly distinguishing aspects of the disclosure from discussed prior art, the numbers recited for the particular aspect of the disclosure are not approximates unless the word “about” is recited.
Although there are alternatives for various components, parameters, operating conditions, etc. set forth herein, that does not mean that those alternatives are necessarily equivalent and/or perform equally well. Nor does it mean that the alternatives are listed in a preferred order unless stated otherwise. Unless otherwise stated, any of the groups defined below can be substituted or unsubstituted.
Directions and other relative references (e.g., inner, outer, upper, lower, etc.) may be used to facilitate discussion of the drawings and principles herein, but are not intended to be limiting. For example, certain terms may be used such as “inside,” “outside,” “top,” “down,” “interior,” “exterior,” and the like. Such terms are used, where applicable, to provide some clarity of description when dealing with relative relationships, particularly with respect to any illustrated components/aspects of the disclosure. Such terms are not, however, intended to imply absolute relationships, positions, and/or orientations. For example, with respect to an object, an “upper” part can become a “lower” part simply by turning the object over. Nevertheless, it is still the same part and the object remains the same.
In order to facilitate review of the various aspects of the disclosure, the following explanations of specific terms are provided:
Aliphatic: A hydrocarbon group having at least one carbon atom to 50 carbon atoms (C1-50), such as one to 25 carbon atoms (C1-25), or one to ten carbon atoms (C1-10), and which includes alkanes (or alkyl), alkenes (or alkenyl), alkynes (or alkynyl), including cyclic versions thereof, and further including straight- and branched-chain arrangements, and all stereo and position isomers as well. Aliphatic groups are distinct from aromatic groups.
Alkenyl: An unsaturated monovalent hydrocarbon having at least two carbon atom to 50 carbon atoms (C2-50), such as two to 25 carbon atoms (C2-25), or two to ten carbon atoms (C2-10), and at least one carbon-carbon double bond, wherein the unsaturated monovalent hydrocarbon can be derived from removing one hydrogen atom from one carbon atom of a parent alkene. An alkenyl group can be branched, straight-chain, cyclic (e.g., cycloalkenyl), cis, or trans (e.g., E or Z).
Alkyl: A saturated monovalent hydrocarbon having at least one carbon atom to 50 carbon atoms (C1-50), such as one to 25 carbon atoms (C1-25), or one to ten carbon atoms (C1-10), wherein the saturated monovalent hydrocarbon can be derived from removing one hydrogen atom from one carbon atom of a parent compound (e.g., alkane). An alkyl group can be branched, straight-chain, or cyclic (e.g., cycloalkyl).
Alkynyl: An unsaturated monovalent hydrocarbon having at least two carbon atom to 50 carbon atoms (C2-50), such as two to 25 carbon atoms (C2-25), or two to ten carbon atoms (C2-10), and at least one carbon-carbon triple bond, wherein the unsaturated monovalent hydrocarbon can be derived from removing one hydrogen atom from one carbon atom of a parent alkyne. An alkynyl group can be branched, straight-chain, or cyclic (e.g., cycloalkynyl).
Aromatic: A cyclic, conjugated group or moiety of, unless specified otherwise, from 5 to 15 ring atoms having a single ring (e.g., phenyl) or multiple condensed rings in which at least one ring is aromatic (e.g., naphthyl, indolyl, or pyrazolopyridinyl); that is, at least one ring, and optionally multiple condensed rings, have a continuous, delocalized Π-electron system. Typically, the number of out of plane Π-electrons corresponds to the Hückel rule (4n+2). The point of attachment to the parent structure typically is through an aromatic portion of the condensed ring system. For example,
However, in certain examples, context or express disclosure may indicate that the point of attachment is through a non-aromatic portion of the condensed ring system. For example,
An aromatic group or moiety may comprise only carbon atoms in the ring, such as in an aryl group or moiety, or it may comprise one or more ring carbon atoms and one or more ring heteroatoms comprising a lone pair of electrons (e.g. S, O, N, P, or Si), such as in a heteroaryl group or moiety. Aromatic groups may be substituted with one or more groups other than hydrogen.
Electrolyte: A substance containing free ions and/or radicals that behaves as an ionically conductive medium.
Haloaliphatic: An aliphatic group wherein one or more hydrogen atoms, such as one to 10 hydrogen atoms, independently is replaced with a halogen atom, such as fluoro, bromo, chloro, or iodo.
Heteroaliphatic: An aliphatic group comprising at least one heteroatom to 20 heteroatoms, such as one to 15 heteroatoms, or one to 5 heteroatoms, which can be selected from, but not limited to oxygen, nitrogen, sulfur, silicon, boron, selenium, phosphorous, and oxidized forms thereof within the group. Alkoxy, ether, amino, disulfide, peroxy, and thioether groups are exemplary (but non-limiting) examples of heteroaliphatic. In some aspects of the disclosure, a fluorophore can also be described herein as a heteroaliphatic group, such as when the heteroaliphatic group is a heterocyclic group.
Substrate: A physical object having a surface onto which an aluminum metal-containing coating can be electroplated, including an aluminum rare-earth alloy coating. Substrates can be solid and/or porous and can have any shape and can be made of any material suitable for having a metallic coating formed thereon. In some aspects of the disclosure, the substrate is a metal-based substrate. In yet other aspects of the disclosure, the substrate may be a non-metal substrate with surface modification with an electrical conducting substance, such as metal and/or conducting carbon layer.
Rechargeable aluminum (Al) battery and room temperature Al electroplating hold a huge potential for the future energy storage system and advanced surface protection methodology toward zero-emission economy. Reducing activation energy and fast kinetic for the electrochemical reduction of aluminum cation from electroactive species in organic solution is one factor lending to the success of these applications, which rely on room temperature processing and highly efficient electrodeposition of Al. Fundamental understanding regarding the AlCl3— solvent interaction and transportation of electroactive species across the concentrations remains ambiguous, which has prevented designing electrolytes for electroplating and rechargeable batteries.
Aluminum-containing electrolytes are known in the art; however, they typically require acidic solutions that rely on using ionic liquids (e.g., tetraalkylammonium, pyridinium, imidazolium, piperidinium, pyrrolidinium cation-containing compounds), inorganic molten salts (e.g., NaCl and/or KCl), and/or organic solvent baths requiring LiAlH4 and/or solvents like DMSO that require using high temperatures (e.g., 130° C. or higher for inorganic molten salt systems). Such compositions have drawbacks that limit their use, particularly for preparing aluminum batteries and aluminum electroplating. For example, such compositions exhibit high corrosivity towards aluminum anodes and low anodic stability. They also can result in cathode decomposition and/or dissolution. Further, they exhibit undesirable physical properties, such as being highly hygroscopic and viscous, not to mention the fact that they are expensive. Conventional methods for industrial aluminum deposition utilize hot-dip coating processes, wherein substrates (e.g., stainless steel) are immersed into molten aluminum at very high temperatures (e.g., 740° C.). Such methods are expensive and create environmental safety/efficiency concerns.
Aspects of the disclosure are directed to an aluminum-ether-based composition comprising an aluminum salt component and an ether-based solvent. The aluminum-ether-based composition is useful in electrodeposition methods and as an electrolyte for use with aluminum-based batteries and/or electrochemical cells. The ether-based solvents of the aluminum-ether-based composition exhibit desirable chelation with the aluminum salt component so as to form a fast ligand exchange complex with the aluminum salt component. Without being bound by a single theory, it currently is believed that this fast ligand exchange complex enables Al electroplating at room temperature with low overpotential. The weak coordination and fast exchange of the ether-based solvent bypass the energetically unfavorable desolvation process, thus reducing the overpotential of Al plating and eliminates the unfavorable reduction of the ether-based solvent at low overpotential. In addition, the ether-based solvent also reduces acidity of the aluminum salt component via complexation and inhibit its catalysis of H2O dissociation, thereby reducing hygroscopicity of aluminum-ether-based composition. In other aspects of the disclosure, a method is disclosed which is directed to aluminum metal electrodeposition and/or reversible aluminum ion electrochemistry using the disclosed aluminum-ether-based composition. The method of the present disclosure can be conducted at room temperature and can provide a cost-effective, low-carbon footprint alternative to conventional aluminum deposition/electrochemical methods. Further, the chemical composition of deposited aluminum can be controlled to enhance chemical resiliency and mechanical properties.
Compositions and Coatings
Aspects of the present disclosure are directed to an aluminum-ether-based composition for use in providing an aluminum-based coating and/or for use as an electrolyte in a battery or electrochemical system. In particular aspects of the disclosure, the aluminum-ether-based composition comprises an aluminum salt component and an ether-based solvent (or a combination of multiple ether-based solvents). In some independent aspects, the aluminum-ether-based composition does not comprise, or is free of a metal hydride, an ionic liquid, or a combination thereof. In some aspects of the disclosure, the aluminum-ether-based composition consists essentially of an aluminum salt component and an ether-based solvent. In such aspects of the disclosure, the aluminum-ether-based composition is free of components that deleteriously affect the ability of the aluminum-ether-based composition to deposit aluminum, to function as an electrolyte, and/or that increases hygroscopicity of the aluminum-ether-based composition. Such components can include, but are not limited to, a metal hydride (e.g., a lithium aluminum hydride), and/or an ionic liquid (e.g., ethyl pyridinium bromide, 1-ethyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium chloride, and the like). In some aspects of the present disclosure, the aluminum-ether-based composition can consist of an aluminum salt component, an ether-based solvent (or two or more of such components), and one or more optional functional additives added to, for example, increase ionic conductivity of the composition, to improve the morphology of Al coating deposition, and/or reduce flammability. Exemplary such optional functional additives can include metal halides, aluminum salts with polyatomic anions, quaternary ammonium halides, sulfone solvents, pyridine derivatives, organic phosphate compounds, triphenylphosphate, and tributylphosphate.
The aluminum salt component typically is a salt capable of providing Al3+ ions. In particular aspects of the disclosure, the aluminum salt component has a formula AlX3, wherein each X independently is a suitable counterion. In particular aspects of the disclosure, each X independently is a halogen atom, such as Cl, Br, I, F, or combinations thereof. In representative aspects of the disclosure, each X independently is Cl, Br, or I and the aluminum salt can be selected from AlCl3, AlF3, AlBr3, and/or AI(I)3. In some aspects of the disclosure, a mixture of two or more aluminum salt components can be used in the aluminum-ether-based composition.
The ether-based solvent can be selected from compounds having a structure according to a formula R1—O—R2, wherein each of R1 and R2 independently is selected from an aliphatic group, an aromatic group, a heteroaliphatic group, a haloaliphatic group, or a combination thereof, wherein any such aliphatic, heteroaliphatic, or haloaliphatic groups can be linear, branched, or cyclic. In particular aspects of the disclosure, each of R1 and R2 independently is selected from alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl, haloalkyl, haloalkenyl, haloalkynyl, aryl, heteroaryl, or any combination thereof, and wherein any of the groups other than aryl and heteroaryl can be linear, branched, or cyclic. In some aspects of the disclosure, each of R1 and R2 independently is selected from C1-20alkyl, C2-20alkenyl, C2-20alkynyl, C1-20heteroalkyl, C2-20heteroalkenyl, C2-20heteroalkynyl, C1-20haloalkyl, C2-20haloalkenyl, C2-20haloalkynyl, C6-15aryl, C1-15heteroaryl, or any combination thereof, and wherein any of the groups other than C6-15aryl and C1-15heteroaryl groups can be linear, branched, or cyclic. In particular aspects of the disclosure of the ether-based solvent, each of R1 and R2 independently is selected from C3-20alkyl, C3-20alkenyl, C3-20alkynyl, C3-20haloalkyl, C3-20haloalkenyl, or C3-20haloalkynyl, wherein any such groups can be linear, branched, or cyclic. In yet other particular aspects of the disclosure, each of R1 and R2 independently is selected from C3-10alkyl, C3-10alkenyl, C3-10alkynyl, C3-10haloalkyl, C3-10haloalkenyl, or C3-10haloalkynyl, wherein any such groups can be linear, branched, or cyclic. In representative aspects of the disclosure, each of R1 and R2 independently is selected from propyl (including linear, branched, or cyclic versions thereof), butyl (including linear, branched, or cyclic versions thereof), pentyl (including linear, branched, or cyclic versions thereof), hexyl (including linear, branched, or cyclic versions thereof), septyl (including linear, branched, or cyclic versions thereof), octyl (including linear, branched, or cyclic versions thereof), nonyl (including linear, branched, or cyclic versions thereof), decyl (including linear, branched, or cyclic versions thereof), or any such groups wherein at least one carbon atom is replaced with a halogen, such as Cl, F, I, or Br, with particular halogenated compounds comprising F. In particular aspects, each of R1 and R2 independently is selected from n-propyl, n-butyl, or n-pentyl. Representative ether-based solvents can include, but are not limited to, dipropyl ether (or “DPE”), dibutyl ether (or “DBE”), diethyl ether (or “DEE”), or pentafluoroethyl ethyl ether, 1,1,1,2,2-pentafluoro-2-(perfluoroethoxy)ethane, trifluoro(trifluoromethoxy)methane, methoxyperfluorobutane, 1-methoxyheptafluoropropane, 4-(trifluoromethoxy)-1-fluorobenzene, 4-fluoroanisole, or combinations thereof. In some aspects of the disclosure, a mixture of ether-based solvents can be used, such as mixture of two or more ether-based solvents, such as a mixture of two or more of the above-mentioned ether-based solvents.
In yet further aspects of the disclosure, the aluminum-ether-based composition can comprise the aluminum salt component in combination with a rare earth element component. In such aspects of the disclosure, the aluminum-ether-based composition can comprise a rare earth element component having a formula according to REE(Z)n, wherein REE is a rare earth element selected from lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), scandium (Sc), yttrium (Y), or combinations thereof; and n is an integer selected from 1 to 4, such as 1, 2, 3, or 4. Each Z group of formula REE(Z)n independently is selected from a halogen (e.g., Br, C1, F, I, or a combination thereof); a polyatomic anion (e.g., PF6, ClO4, BF4, TFSI, FSI, carboxylates and their fluorinated derivatives thereof, or any combination thereof); an alkoxy group having a formula R30− (wherein the REE is bound to or coordinated with the oxygen atom); or a combination thereof. With reference the formula R30−, R3 is selected from an aliphatic group, an aromatic group, a haloaliphatic group, or a combination thereof, wherein any such aliphatic or haloaliphatic groups can be linear, branched, or cyclic. In particular aspects of the disclosure, R3 is selected from alkyl, alkenyl, alkynyl, haloalkyl, haloalkenyl, haloalkynyl, aryl, heteroaryl, or any combination thereof, and wherein any of the groups other than aryl and heteroaryl can be linear, branched, or cyclic. In some aspects of the disclosure, R3 is selected from C1-20alkyl, C2-20alkenyl, C2-20alkynyl, C1-20haloalkyl, C2-20haloalkenyl, C2-20haloalkynyl, C6-15aryl, C1-15heteroaryl, or any combination thereof, and wherein any of the groups other than C6-15aryl and C1-15heteroaryl groups can be linear, branched, or cyclic. In particular aspects of the disclosure, R3 is selected from C3-20alkyl, C3-20alkenyl, C3-20alkynyl, C3-20haloalkyl, C3-20haloalkenyl, or C3-20haloalkynyl, wherein any such groups can be linear, branched, or cyclic. In yet other particular aspects of the disclosure, R3 is selected from C3-10alkyl, C3-10alkenyl, C3-10alkynyl, C3-10haloalkyl, C3-10haloalkenyl, or C3-10haloalkynyl, wherein any such groups can be linear, branched, or cyclic. In representative aspects of the disclosure, R3 is selected from propyl (including linear, branched, or cyclic versions thereof), butyl (including linear, branched, or cyclic versions thereof), pentyl (including linear, branched, or cyclic versions thereof), hexyl (including linear, branched, or cyclic versions thereof), septyl (including linear, branched, or cyclic versions thereof), octyl (including linear, branched, or cyclic versions thereof), nonyl (including linear, branched, or cyclic versions thereof), decyl (including linear, branched, or cyclic versions thereof), or any such groups wherein at least one carbon atom is replaced with a halogen, such as Cl, F, I, or Br, with particular halogenated compounds comprising F. In particular aspects of the disclosure, the rare earth component has a formula REE(Z)n, wherein REE is Ce, Z is Cl, and n is 3.
In some independent aspects, any aluminum-ether-based composition comprising an aluminum salt component in combination with a rare earth element component does not comprise, or is free of a metal hydride, an ionic liquid, or a combination thereof. In some aspects of the disclosure, an aluminum-ether-based composition comprising a combination of an aluminum salt component and a rare earth element component consists essentially of the aluminum salt component, the rare earth element component, and an ether-based solvent. In such aspects of the disclosure, the aluminum-ether-based composition is free of components that deleteriously affect the ability of the aluminum-ether-based composition to deposit an aluminum-rare earth alloy or that increases hygroscopicity of the aluminum-ether-based composition. Such components can include, but are not limited to, a metal hydride (e.g., a lithium aluminum hydride) and/or an ionic liquid (e.g., ethyl pyridinium bromide, 1-ethyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium chloride, and the like). In some aspects of the present disclosure, an aluminum-ether-based composition comprising a combination of an aluminum salt component and a rare earth element component consists of the aluminum salt component, the rare earth element component, the ether-based solvent (or two or more of such components), and one or more optional functional additives added to, for example, increase ionic conductivity of the composition, to improve the morphology of Al coating deposition, and/or reduce flammability. Exemplary such optional functional additives can include metal halides, aluminum salts with polyatomic anions, quaternary ammonium halides, sulfone solvents, pyridine derivatives, organic phosphate compounds, triphenylphosphate, and tributylphosphate.
The amount of the aluminum salt component and the ether-based solvent can be selected to provide a suitable viscosity of the aluminum-ether-based composition for use in method aspects described herein. In some aspects of the disclosure, the viscosity is not so viscous that atoms of components of the aluminum-ether-based composition are immobilized when a voltage is applied and/or when the aluminum-ether-based composition is at ambient temperature. In some aspects of the disclosure, the viscosity of the aluminum-ether-based composition is typically such that atoms are able to be mobile when a voltage is applied and/or when the aluminum-ether-based composition is at ambient temperature. In some aspects of the disclosure, the viscosity of electrolyte might vary depend on salts and additives concentration but typically can be below 10 mPa·s. In some aspects of the disclosure, the aluminum salt component can be present in an amount that provides a molar ratio of aluminum salt component:ether-based solvent (wherein the ether-based solvent component is the amount of a single ether-based solvent or a total amount if two or more such solvents are used) ranging from 0.01 to 50, such as 0.125 to 50, or 0.5 to 25, or 0.5 to 15, or 0.5 to 10, or 0.5 to 5, or 0.5 to 2, or 0.5 to 1.5 or 0.5 to 1. In particular aspects of the disclosure, the amount of aluminum salt component is an amount that provides a molar ratio of aluminum salt component:ether-based solvent that ranges from 0.01 to 1.5, such as 0.5 to 1, or 0.5 to 0.83 or 0.5 to 0.71. In particular aspects of the disclosure, the aluminum salt component is present in an amount providing a molar ratio of aluminum salt component:ether-based solvent that is 0.5, 0.71, 0.83, or 1. In yet additional aspects of the disclosure, the aluminum salt component can be present in an amount that provides a molar concentration ranging from greater than 0 M to 10 M, such as 1 M to 10 M, or 2 M to 8 M, or 2.9 M to 7.3 M, or 2.9 M to 6.1 M, or 2.9 M to 5.2 M, or 2.9 M to 4.8 M, or 3.7 M to 7.3 M, or 3.7 M to 6.1 M, or 3.7 M to 5.2 M. In particular representative aspects of the disclosure, the concentration of the aluminum salt component is 2.9 M, 3.7 M, 4.1 M, 4.8 M, 5.2 M, 5.8 M, 6.1 M, or 7.3 M. In aspects of the disclosure comprising a rare earth element component, the rare earth element component can be included at a concentration ranging from 0.001 M to 5 M, such as 0.01 M to 5M, or 0.1 M to 5 M, or 0.25 M to 5 M, or 0.5 M to 5 M, or 1 M to 5M. In representative aspects of the disclosure the rare earth element component is included at a concentration of 0.25 M.
Representative examples of the aluminum-ether-based composition of the present disclosure can comprise AlCl3 and DPE; AlCl3 and DBE; AlBr3 and DPE; AlBr3and DBE; AI(I)3 and DPE; AI(I)3 and DBE; AlF3 and DPE; AlF3 and DBE; AlCl3, CeCl3, and DPE; or AlCl3, CeCl3, and DBE. For example, some representative examples can include AlCl3:DPE at molar ratio of 1, 0.83, 0.5, 0.25; AlCl3:DBE at molar ratio of 1, 0.83, 0.5, 0.25; AlCl3:DPE at molar ratio of 0.5 with addition of CeCl3 less than 0.25 M; and AlCl3:DBE at molar ratio of 0.5 with addition of CeCl3 less than 0.25 M.
Without being limited to a single theory of operation, it currently is believed that the aluminum salt component and the ether-based solvent are able to form electroactive species through solvent-solute interactions and that the disclosed aluminum salt components and ether-based solvents are able to form fast ligand exchange complexes that facilitate aluminum deposition at ambient temperatures with low overpotential. It also is currently believed that the ether-based solvents exhibit a level of basicity that reduces the acidity of the aluminum salt component and thus inhibits catalysis of H2O dissociation, thereby reducing the hygroscopicity of the aluminum-ether-based composition. In some aspects of the disclosure, the aluminum-ether-based composition is used to form an aluminum-based coating that exhibits desirable morphology and/or durability. In particular aspects of the disclosure, the coating is even along the surface of the substrate on which it is formed and does not exhibit patches of aluminum that are deposited randomly over the surface area of the substrate (or at least exhibits a low number of such patches). In some aspects of the disclosure, the coating can be slightly porous, with particular aspects of the disclosure exhibiting a porosity ranging from greater than 0 to less than 0.1%, such as 0.01% to 0.1%. In some aspects of the disclosure, the deposited coating can comprise polycrystalline aluminum, a nanofilm of aluminum, and/or amorphous aluminum.
In some aspects of the disclosure, the aluminum-based coating can be deposited on a substrate. In some aspects of the disclosure, the substrate can be an electrically conductive substrate or a non-conductive substrate with or without an applied conductive coating. In particular aspects of the disclosure, the substrate can be a metal substrate, such as a Mo substrate, a copper (Cu) substrate, a Zr substrate, a steel substrate, a uranium (U) substrate, an aluminum (Al) substrate, a gold (Au) substrate, or substrates comprising combinations of any such materials. Exemplary non-conductive substrates can include, but are not limited to, substrates comprising polyethylene terephthalate, Teflon®, cotton paper, non-woven glass, epoxy, and ceramic materials.
In some aspects of the disclosure, the integrity and/or physical features of the aluminum-based coating provided by the aluminum-ether-based composition can be measured. Such measurements can involve using X-ray fluorescence (XRS) to determine atomic composition of a coating; scanning electron microscopy (SEM) to evaluate coating thickness; optical microscopy to evaluate coating uniformity; energy dispersive spectroscopy (EDS) to evaluate the chemical make-up of the coating; X-ray photoelectron spectroscopy (XPS) to evaluate surface states and chemistry; X-ray diffraction (XRD) to evaluate the crystallinity and composition of the coating; and/or oxidation experiments to determine coating thickness, variation, and/or to confirm the presence of the coating. Some such techniques are discussed herein.
In some aspects of the disclosure, thin aluminum-based coatings can be prepared using the aluminum-ether-based composition of the present disclosure. In some aspects of the disclosure, the aluminum-ether-based composition can be used to provide a coating having any desired thickness, which can be determined depending on the desired end use. In particular aspects of the disclosure, the thickness can be modified by controlling the current and/or duration of coating application. In some aspects of the disclosure, substrates comprising a thin coating of aluminum (and/or an alloy thereof) are desirable in certain industries and can be made using an aluminum-ether-based composition of the present disclosure.
Methods
Aspects of the disclosure also are directed to a method for using the aluminum-ether-based composition of the present disclosure. The method comprises exposing a system comprising an aluminum-containing substrate and a second substrate to an aluminum-ether-based composition of the present disclosure and applying a voltage to the system. In particular aspects of the present disclosure, the method comprises applying a voltage to a system comprising an aluminum-containing substrate, a second substrate, and an aluminum-ether-based composition according to the present disclosure, wherein the aluminum-containing substrate and the second substrate are positioned at a distance from one another, and the aluminum-ether-based composition comes into fluid contact with both the aluminum-containing substrate and the second substrate.
In some aspects of the disclosure, the method is an electrodeposition method wherein the aluminum-ether-based composition is used to provide a deposited layer of aluminum metal and/or an aluminum-rare earth element alloy on a substrate. In such aspects of the disclosure, the aluminum-containing substrate is provided as a counter electrode and the second substrate comprises a metal substrate capable of acting as a working electrode upon which aluminum metal and/or an aluminum-rare earth element alloy can be deposited. The aluminum-containing substrate can comprise aluminum metal or an aluminum alloy. In aspects of the disclosure employing an aluminum alloy substrate, the aluminum alloy can comprise aluminum and a rare earth element selected from Ce, La, Gd, Nd, Dy, Pr, Tb, Y, Sc, Eu, Sm, Er, Ho, Lu, Tm, Yb, Pm, or combinations thereof. In particular aspects of the disclosure, the aluminum alloy is an aluminum-cerium alloy. The aluminum-ether-based composition serves as a source of Al3+ ions (or Al3+ and REEn++ ions) that can be reduced and deposited on the second substrate as aluminum metal. In such aspects of the disclosure, the voltage applied to the system is provided as a negative potential or a negative current and is applied to the second substrate.
Aspects of the method disclosed herein can be used to deposit aluminum-based coatings on substrates, such as those described herein. In some aspects of the disclosure, the aluminum-based coating can fully or partially coat the surface area of the substrate. For example, in some aspects of the disclosure, for any particular amount of surface area that is desired to be coated with the aluminum-based coating using the aluminum-ether-based composition can be coated such that more than 80% to 100% of that desired surface area can be coated with the aluminum-based coating, such as greater than 80% to 100%, or 90% to 100%, or 95% to 100%, or 98% to 100%.
In some other aspects of the disclosure, the method is an electrochemical method wherein the aluminum-ether-based composition is used as an electrolyte that facilitates Al3+ transport between an anode and a cathode. In such aspects of the disclosure, the aluminum-containing substrate serves as an aluminum anode and the second substrate is selected from a material capable of serving as a cathode. In some aspects of the disclosure, the cathode can be a metal-halide-based cathode (e.g., a metal-chloride- and/or metal-fluoride-based cathode), a vanadium-based cathode, an organic cathode (e.g., a carbon-based cathode and/or a sulfur-based cathode), or a metal chalcogenide-based cathode. In such aspects of the disclosure, the disclosed aluminum-ether-based composition can be used as an electrolyte in view of its ability to promote reversible aluminum plating and stripping. In some aspects of the disclosure, the voltage used in the method is a charging voltage and is applied as DC, AC, or a combination thereof. Applying the voltage to the system results in Al3+ ion transport between the aluminum anode and the cathode and through the aluminum-ether-based composition. In such aspects of the disclosure, applying the voltage to the system produces electrical energy. The system used in such methods can further comprise a separator and/or a membrane.
Overview of Several Aspects of the Disclosure
Disclosed herein are aspects of an aluminum-ether-based composition for use in electroplating an aluminum metal coating or for use in an aluminum battery, comprising: an aluminum salt component having a structure according to a formula AlX3, wherein each X independently is a halogen atom; and an ether-based solvent having a structure according to a formula R1—O—R2, wherein each of R1 and R2 independently is selected from C3-20alkyl, C3-20alkenyl, C3-20alkynyl, C3-20haloalkyl, C3-20haloalkenyl, or C3-20haloalkynyl; wherein the aluminum salt component and the ether-based solvent are present in amounts that provide a molar ratio of 0.01 to 1.5 (aluminum salt component:ether-based solvent) and the aluminum-ether-based composition does not comprise, or is free of, a metal hydride and/or an ionic liquid.
In any or all aspects of the disclosure, the aluminum salt component is AlCl3, AlF3, AlBr3, AI(I)3, or a combination thereof.
In any or all of the above aspects of the disclosure, the aluminum salt component is AlCl3.
In any or all of the above aspects of the disclosure, each of R1 and R2 independently is selected from C3-10alkyl or C3-10haloalkyl.
In any or all of the above aspects of the disclosure, each of R1 and R2 independently is selected from n-propyl, n-butyl, n-pentyl, or any fluorinated version thereof.
In any or all of the above aspects of the disclosure, the composition comprises AlCl3 and a mixture of two or more ether-based solvents.
In any or all of the above aspects of the disclosure, the molar ratio ranges from 0.5 to 1.
In any or all of the above aspects of the disclosure, the aluminum-ether-based composition further comprises a rare earth element component having a formula REE(Z)n, wherein: REE is selected from lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), scandium (Sc), yttrium (Y), or combinations thereof; each Z independently is selected from a halogen; a polyatomic anion; an alkoxy group having a formula R30−, wherein R3 is selected from an aliphatic group, an aromatic group, a haloaliphatic group, or a combination thereof; or a combination thereof; and n is an integer selected from 3 or 4.
In any or all of the above aspects of the disclosure, the rare earth element component is CeCl3.
Also disclosed herein are aspects of a battery, comprising: the aluminum-ether-based composition according any or all of the above aspects of the disclosure; an aluminum anode; and a cathode.
In any or all of the above aspects of the disclosure, the cathode is a metal-halid-based cathode, a vanadium-based cathode, an organic cathode, or a metal-chalcogenide-based cathode.
In any or all of the above aspects of the disclosure, the aluminum-ether-based composition comprises (i) AlCl3 and (ii) dipropyl ether or dibutyl ether, wherein (i) and (ii) are present in amounts providing a ratio ranging from 0.5 to 1.
Also disclosed herein are aspects of a method, comprising applying a voltage to a system comprising an aluminum-containing substrate, a second substrate, and the aluminum-ether-based composition according to any or all of the above aspects of the disclosure, wherein the aluminum-containing substrate and the second substrate are positioned at a distance from one another, and the aluminum-ether-based composition comes into fluid contact with both the aluminum-containing substrate and the second substrate.
In any or all of the above aspects of the disclosure, the aluminum-containing substrate is an aluminum anode and the second substrate is a cathode.
In any or all of the above aspects of the disclosure, the voltage is a charging voltage and is applied as DC, AC, or a combination thereof.
In any or all of the above aspects of the disclosure, applying the voltage to the system results in Al3+ ion transport between the aluminum anode and the cathode and through the aluminum-ether-based composition.
In any or all of the above aspects of the disclosure, the method produces electrical energy.
In any or all of the above aspects of the disclosure, the system further comprises a separator and/or a membrane component positioned between the aluminum-containing substrate and the second substrate.
In any or all of the above aspects of the disclosure, the aluminum-containing substrate is an aluminum metal counter electrode and the second substrate is a working electrode and comprises a substrate upon which aluminum metal can be deposited upon exposure of the system to the voltage.
In any or all of the above aspects of the disclosure, the voltage is a negative potential versus Al/Al3+, or a negative current applied to the substrate upon which the aluminum metal is deposited.
In any or all of the above aspects of the disclosure, applying the voltage to the system results in electrodepositing an aluminum metal layer on the second substrate; or wherein the aluminum-ether-based composition further comprises a rare earth element component and applying the voltage to the system results in electrodepositing an aluminum-rare earth element alloy layer on the second substrate.
In this example, different compositions were prepared comprising a mixture of AlCl3 and either dipropyl ether (DPE) or dibutyl ether (DBE), using different ratios of AlCl3: solvent and/or different AlCl3 concentrations. The dissolution of AlCl3 into dipropyl ether (DPE) and dibutyl ether (DBE) formed a slight yellowish solution and the color increased at higher concentration of AlCl3. In both solvents, the AlCl3 can be dissolved with the AlCl3:solvent up 1:1 molar ratio and reached its saturation. Certain physical properties of electrolytes with various AlCl3: solvents are summarized in Table 1.
At saturation, the AlCl3 can be dissolved at an equal molar amount with DPE and results in a composition having a high density (e.g., 1.167 g/cm3) (
In this example, molecular dynamics (MD) simulation was used to evaluate complexes formed between AlCl3 and DPE. The MD simulation of the AlCl3.DPE composition (
In this example, NMR analyses of an AlCl3.DPE composition and an AlCl3.DBE composition were conducted. In particular, the composition comprising a molar ratio of the components between 1 and 0.5 was evaluated to confirm the coordination of the DPE and DBE solvents to AlCl3 via AI-O bonding. Coordinating DPE has slightly shorter H—C bond length and overall tighter molecular packing (larger2JH1-c1 and 3JH1-H2). DPE and DBE coordinated to Al more frequently at higher AlCl3 concentration (larger2JH1-c1 and 3JH1-H2 at higher AlCl3 concentration) (
Table 2 shows the fractions of aluminum containing species in AlCl3-DPE and AlCl3-DBE determined using NMR. Aluminum presented in two species, including AlCl4− and neutral species AlCl3.DPE or AlCl3.DBE. In both solvents (DPE and DBE), only neutral species AlCl3.Solvent is existed (100%). At lower AlCl3:solvent less than 1, two species coexisted. The dominant Al species was the AlCl3-DPE or AlCl3-DBE neutral species with the faction of above 99.4% in all range of concentrations evaluated in this example (Table 2). Similar trends were observed in the AlCl3.DBE solution.
27Al NMR analysis of electrolyte solution
In this example, the interaction of AlCl3 with DPE solvent was further investigated using infrared spectroscopy (IR). With the addition of AlCl3 into DPE solvent, C—H vibrations of DPE shows a blue-shift (marked with black arrows in
With the present of AlCl3, significant changes in vas(C—O—C) vibration of DPE solvent were observed. With increased AlCl3 concentration, vas(C—O—C) vibration of free DPE reduced significantly and disappears at 1:1 ratio as indicated by the arrow labeled “A” in
In this example, electrochemical characterization of AlCl3.DPE and ACl3.DBE was conducted using cyclic voltammetry between−0.8 and 2.5 V at scan rate of 0.25 mV s−1 at room temperature (results shown in
The anodic stability of electrolyte was also characterized using both linear sweep voltammetry (LSV) (results shown in
In this example, the morphology, composition, and structure of Al coatings formed via electrodeposition was evaluated, using a representative composition comprising AlCl3 and DPE. The deposition of Al was conducted using galvanostatic discharge for 20 hours at current density of 0.1 mAh cm−2. A grey to silver deposition film was obtained in all aluminum-ether-based compositions between 0.83 to 0.5. At the molar ratio of 0.5, a good deposition of Al was obtained while a porous film was obtained at higher concentrations of AlCl3.
Surface analysis of Al deposition film AlCl3.DPE was conducted using X-ray photoelectron spectroscopy (see
In this example, a rechargeable Al battery was fabricated using V2O5 loaded on activated carbon cloth (ACC) as the cathode, Al foil as the anode, and glass fiber as the separator. AlCl3.DPE (molar ratio of 0.5) was used as the electrolyte.
In this example, an Al—Ce alloy coating was deposited using a composition according to the present disclosure. To deposit the Al—Ce alloy, a small amount (0.25 M) of CeCl3 (Ce3++3e−⇄Ce, −2.336 V) was added to AlCl3:DPE (0.5) and stirred for 12 hours. The CeCl3 reached its saturation level and small amount of CeCl3 crystal remained in the vial. The clear solution was separated and used for electrochemical testing.
XPS analysis of the deposited metal film revealed the presentation of metallic Al, along with small amount of Al2O3 and AlCl3 (
In view of the many possible aspects of the disclosure to which the principles of the present disclosure may be applied, it should be recognized that the illustrated aspects of the disclosure are only preferred examples and should not be taken as limiting the scope of the disclosure. Rather, the scope is defined by the following claims. We therefore claim as our invention all that comes within the scope and spirit of these claims.
This application claims the benefit of the earlier filing date of U.S. Provisional Application No. 63/327,195 filed on Apr. 4, 2022, which is incorporated herein by reference in its entirety.
This invention was made with government support under Contract DE-AC0576RL01830 awarded by the U.S. Department of Energy. The government has certain rights in the invention.
| Number | Date | Country | |
|---|---|---|---|
| 63327195 | Apr 2022 | US |
