WO2016004189A1

WO2016004189A1 - Selected compositions for aluminum processes and devices

Info

Publication number: WO2016004189A1
Application number: PCT/US2015/038807
Authority: WO
Inventors: Hunaid B. NULWALA; John D. WATKINS
Original assignee: Nulwala Hunaid B; Watkins John D
Priority date: 2014-07-03
Filing date: 2015-07-01
Publication date: 2016-01-07

Abstract

A selected electrolyte composition comprising aluminum and a lower molecular weight fluorinated organic anion which can be an ionic liquid. The fluorinated organic anion can be bis(trifluorosulfonyl)imide. The composition can be used in electroplating or batteries. A preferred example is use of Al(NTf₂)₃ with one or more other moieties. A moisture insensitive electroplating method comprising: providing at least one aluminum electroplating system comprising at least one electroplating composition which is adapted for electroplating aluminum onto a substrate; electroplating aluminum onto the substrate from the at least one electroplating composition comprising: (i) aluminum cation, and (ii) at least one anion which is a fluorinated organic anion having molecular weight of 750 g/mol or less. Optionally, the aluminum cation is in, or is not in, aluminate form. Use of highly reactive aluminum compounds such as aluminum halides can be avoided.

Description

SELECTED COMPOSITIONS FOR ALUMINUM PROCESSES AND

DEVICES

RELATED APPLICATIONS

This application claims priority to US provisional application 61/998,637 filed July 3, 2014 which is hereby incorporated by reference in its entirety for all purposes.

GOVERNMENT SUPPORT

This invention was made with government support under the Department of Energy DE-FE0004000. The government has certain rights in this invention.

BACKGROUND

Aluminum is a critical metal in many, diverse technologies ranging from, for example, metal electrodeposition, batteries, cans, aeroplanes, and catalysis. In particular, metal electrodeposition, including aluminum

electrodeposition, is an integral manufacturing step for a variety of

applications including coatings and heat barrier layers. Aluminum alloys also are critical.

In the case of aluminum, as aluminum itself is quite expensive, electroplating it onto cheaper materials allows for economical and corrosion- resistant plated metal. The current state of the art for aluminum deposition onto metal substrates typically employs electrolysis of aluminum trichloride (AICI3) in a toluene solution. This process is usually conducted at elevated temperatures (e.g., 80°C), and toluene is both volatile and flammable. Under the conditions of the process, the solvent is above its flashpoint and as such represents a safety and environmental hazard. A method which makes use of a non-volatile, non-flammable solvent under commercially realistic conditions would be a major improvement to the process. Also, aluminum complexes can be pyrophoric.

Ionic liquids (ILs) can in some cases provide an effective system for efficient and safe aluminum deposition (see, for example, Wilkes et al.,

Inorganic Chemistry, 1982, 21(3), 1263-1264; Abbott, et al., Application of ionic liquids to the electrodeposition of metals. Physical chemistry chemical physics : PCCP 2006, 8, 4265-79; Pomfret et al. , Electrochemical Template Deposition of Aluminum Nanorods Using Ionic Liquids. Chemistry of Materials 2008, 20, 5945-5947; and Zhang et al., New electrolytes for aluminum production Ionic liquids. JOM 2003, 55, 54-57). More generally, see

Electrodeposition from Ionic Liquids, (Eds. Endres, MacFarlane, and Abbott, Eds.), Wiley-VCH, 2008.

ILs are most commonly defined as salts with melting points below 100 °C, and many ILs are liquid at room temperature (RTILs). One ion has a delocalized charge and one component is organic, and this provides ILs with many unique properties such as negligible vapor pressure, low flammability, and low volatility to name a few. One can tune the properties of the IL, for example, by variation of the counterion structure and other methods. ILs also possess a wide electrochemical window.

U.S. Patent Publication 2009/0236227 describes use of ionic liquids in electroplating or electropolishing. However, the description is not broad but is limited to ammonium embodiments. Also, the ionic liquid must either have a fatty alky! chain or an N-acyl sulphonylimide type of anion. This again significantly limits the types of ionic liquids which can be used and types of improvements which can be made. Also, although the description mentions aluminum, no data or working examples are presented for aluminum deposition or electroplating.

U.S. Patent Publication 2012/0006688 describes use of ionic liquids in electrochemical deposition of aluminum, but requires use of selected additives described as formulae (I), (II), and (III).

Despite these advances, a need exists to develop better electrolyte and ionic liquid systems, compositions, and methods for aluminum

electrodeposition in particular. The systems, compositions, and methods should be relatively safe, environmentally friendly, and commercially realistic and also should provide high quality films. These electrolyte compositions should be versatile and can be also used in other electrolyte applications such as, for examples, batteries or catalysis. New uses for aluminum compositions are also needed.

SUMMARY Embodiments described herein include compositions, methods of using compositions, methods of making compositions, and larger devices and systems involving the compositions.

A first aspect is a composition which is an electrolyte and is

represented by the composition of Formula (I), or a composition of Formula (II), or a composition representing a mixture of the compositions of Formulae (I) and (II), but optionally wherein the electrolyte composition has one or more additional components in the composition:

(I) [C⁺]_a[AI³⁺]b{[FOA-]₃}c[Y-]d

(II) [C⁺]x[AI(FOA-)3(Y-)]yrY-.z

wherein C⁺ in Formulae (I) and (II) represents a cation other than aluminum; wherein FOA^" in Formulae (I) and (II) represents a fluorinated organic anion having molecular weight of 750 g/mol or less; wherein Y^* in Formulae (I) and (II) represents an anion which optionally may be a fluorinated organic anion having molecular weight of 750 g/mol or less represented by FOA^" or may be different; wherein Formula (I) is free of the aluminate anion; wherein in

Formula (II) [AI(FOA^")3(Y^')] represents an aluminate anion; wherein in Formula

(I) , subscripts a, b, c, and d are non-zero and adapted for charge neutrality between cations C⁺ and Al³⁺ and anions FOA^" and Y^"; and wherein in Formula

(II) , subscripts x, y, and z are adapted for charge neutrality between the cation C+ and the aluminate anion [AI(FOA^")₃(Y^~)] and Y^". For clarity, the [Y^"]_z is not part of the aluminate anion. Also, x and y are non-zero but z can be zero or non-zero so Y^' is optional.

A second aspect is a composition which is an electrolyte and is prepared by mixing: (i) AI(FOA)₃, wherein FOA is a fluorinated organic anion having a molecular weight of less than 750 g/mol, with (ii) at least one additional salt component represented by [C⁺][Y^"], wherein C⁺ represents a cation other than aluminum, and wherein Y^" represents an anion which optionally may be a fluorinated organic anion having molecular weight of 750 g/mol or less represented by FOA or may be different. In other embodiments, in the second aspect, the composition is prepared by mixing the additional salt component (ii) not with AI(FOA)₃ but rather with AI(FOA)₂X or AI(FOA)X₂. or combinations thereof, wherein X is a halide such as chloride or bromide. In one embodiment, the composition is the composition represented by Formula (I) but not Formula (II). In another embodiment, the composition represented by Formula (II) but not Formula (I). In another embodiment, the composition can be a mixture of compositions each represented by Formula (I) and Formula (II).

In one embodiment, the fluorinated organic anion is triflate,

trifluoroacetate, or a bis(fluorosulfonyl)imide anion. In another embodiment, the fluorinated organic anion is a fluorosulfonyl anion. In another embodiment, the fluorinated organic anion is a bis(fluorosulfonyl)imide anion. In another embodiment, the fluorinated organic anion is bis(trifluoromethylsulfonyl)imide anion (NTf2).

In one embodiment, the cation C⁺ is an organic cation. In another embodiment, the cation C⁺ is an organic cation which comprises nitrogen in a heterocyclic ring or an organic cation which is an ammonium cation. In another embodiment, the cation C⁺ is an ammonium, pyrrolidinium,

imidazolium, pyridinium, piperidinium, phosphonium, pyrazolium, or sulfonium cation. Other cations which are useful for ionic liquids can be used. In another embodiment, the cation C⁺ is an ammonium cation. In some

embodiments, the cation C+ is not an imidazolium cation, including not an HMIM or EMIM cation.

In one embodiment, the anion Y^" is a fluorinated organic anion (FOA^"). In another embodiment, the anion Y^" is a fluorinated borate or a fluorinated phosphate anion. In another embodiment, the anion Y^" is a halide. In another embodiment, the anion Y^" is not a halide.

In one embodiment, the cation C⁺ is an ammonium cation and the anion Y^" is a fluorinated borate or a fluorinated phosphate anion.

In one embodiment, Y^" is bis(trifluoromethylsulfonyl)imide anion and FOA^' is bis(trifluoromethylsulfonyl)imide anion.

In some embodiments, the composition is an ionic liquid, including a room temperature ionic liquid.

Other embodiments include a method comprising electroplating aluminum from an electroplating composition according to embodiments described herein. In some embodiments, the electroplating composition comprises at least 1 wt.% water. In some embodiments, the electroplating of aluminum is an electroplating of aluminum alloy. In some embodiments, the electroplating composition comprises at least one organic solvent. In some embodiments, the electroplating composition comprises at least one additive.

Other embodiments include a method comprising completing an electrochemical circuit, including a battery electrochemical circuit, with use of an electrolyte composition according to embodiments described herein.

Other embodiments include a device comprising the composition according to embodiments described herein. The device can be a battery, including an aluminum battery.

A third aspect is a method comprising: providing at least one aluminum electroplating system comprising at least one substrate to be electroplated with aluminum; at least one electroplating composition which is adapted for electroplating aluminum onto the substrate; at least one counter electrode; and at least one electrical energy source to drive the electroplating;

electroplating aluminum onto the substrate from the at least one electroplating composition, wherein the electroplating composition comprises: (i) aluminum cation, and (ii) at least one anion which is a fluorinated organic anion having molecular weight of 750 g/mol or less.

In one embodiment, the aluminum cation is not in aluminate form. In another embodiment, the aluminum cation is in aluminate form.

In some embodiments, the fluorinated organic anion is triflate, trifluoroacetate, or a bis(fluorosulfonyl)imide anion. In some embodiments, the fluorinated organic anion is a bis(fluorosulfonyl)imide anion. In some embodiments, the fluorinated organic anion is bis(trifluoromethylsulfonyl)imide anion. In some embodiments, the electroplating composition is prepared with use of AI(NTf₂)₃.

In some embodiments, the molar ratio of aluminum cation to fluorinated organic anion is equal to or less than 1 :1. In some embodiments, the molar ratio of aluminum cation to fluorinated organic anion is equal to or less than 1 :3.

In some embodiments, the aluminum cation is not in the form of Al-X bonding wherein X is a halide. In some embodiments, the aluminum cation is not in the form of a haloaluminate. In some embodiments, the aluminum cation is not in the form of a chloroaluminate. In some embodiments, the electroplating composition comprises at least one additional cation besides aluminum and at least one additional anion which is different than the organic fluorinated anion and is not an aluminate anion. In some embodiments, the electroplating composition comprises at least one additional anion besides the organic fluorinated anion which is an inorganic anion. In some embodiments, the electroplating composition comprises at least one additional anion besides the organic fluorinated anion which is a fluorinated inorganic anion. In some embodiments, the

electroplating composition comprises at least one additional anion besides the organic fluorinated anion which is a borate or phosphate anion.

In some embodiments, the electroplating composition is an ionic liquid. In some embodiments, the electroplating composition is a room temperature ionic liquid. In some embodiments, the electroplating composition comprises at least 1 wt.% water. In some embodiments, the electroplating is carried out under open environmental conditions.

A fourth aspect is a method comprising (i) catalyzing a polymerization reaction, (ii) catalyzing a Friedel-Crafls reaction, or (iii) sensing a target with use of a composition which comprises or is prepared from AI(FOA)₃, wherein FOA is a fluorinated organic anion having a molecular weight of less than 750 g/mol.

In one embodiment, the method comprises (i) catalyzing a

polymerization reaction but not (ii) catalyzing a Friedel-Crafts reaction or (iii) sensing a target. In another embodiment, the method comprises (ii) catalyzing a Friedel-Crafts reaction but not (i) catalyzing a polymerization reaction or (iii) sensing a target. In another embodiment, the method comprises (iii) sensing a target but not (i) catalyzing a polymerization reaction or (ii) catalyzing a Friedel-Crafts reaction.

In some embodiments, FOA is a fluorosulfonyl anion, or a

bis(trifluorosulfonyl)imide anion.

An additional aspect is a method comprising: providing at least one aluminum electroplating system comprising at least one substrate to be electroplated with aluminum; at least one electroplating composition which is adapted for electroplating aluminum onto the substrate; at least one counter electrode; and at least one electrical energy source to drive the electroplating; electroplating aluminum onto a substrate from at least one electroplating composition which is adapted for electroplating aluminum onto the substrate, wherein the electroplating composition is prepared from a salt which comprises: (i) aluminum cation, and (ii) at least one anion which is a fluorinated organic anion having molecular weight of 750 g/mol or less.

Another aspect is a composition comprising at least one electroplating composition which is adapted for electroplating aluminum onto a substrate in an electroplating system; wherein the electroplating composition comprises:

(i) aluminum cation, and (ii) at least one anion which is a fluorinated organic anion having molecular weight of 750 g/mol or less.

Still further, another aspect is a composition comprising at least one electroplating composition which is adapted for electroplating aluminum onto a substrate in an electroplating system, wherein the electroplating

composition is prepared from a salt which comprises: (i) aluminum cation, and

(ii) at least one anion which is a fluorinated organic anion having molecular weight of 750 g/mol or less.

Also provided herein is an article comprising at least one substrate having at least one film disposed on the substrate, wherein the film is disposed on the substrate using the compositions and/or methods described herein. The film can be present in amounts sufficient to improve corrosion resistance of the substrate.

A variety of advantages can be found for one or more embodiments. One advantage for at least some embodiments is providing a method for electroplating aluminum which is relatively insensitive to air and/or water. Another advantage for at least some embodiments is high quality, defect free, smooth aluminum films. Another advantage for at least one embodiment is fast deposition of metal. Another advantage for at least one embodiment is lower viscosity in the ionic liquid and during electroplating. Another advantage for at least one embodiment is better mass transfer in the ionic liquid and during electroplating. Another advantage for at least some embodiments is the ability to obtain good results without use of specialized additives. Another advantage for at least one embodiment is avoiding use of toxic metals such as chromium. Additional advantages include, for example, versatility in uses of compounds, salts, and compositions described herein including, for example, use of the materials as catalysts, including catalyst for polymer synthesis; as agents or catalysts for Friedel-Crafts acylation, and as binding agents for detection.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1. Voltammograms for (i) 10mM and (ii) 20mM of AI(NTf₂)₃ in an acetonitrile solution with 0.1 M NBu₄ PF₆ supporting electrolyte.

Figure 2. Cyclic voltammograms at 50 mVs^"1 on a glassy carbon working electrode for 20 mM AI(NTf₂)3 in acetonitrile with 0.1 M NBu₄PF₆ electrolyte with (i) no explicitly added water and (ii) 1 wt% water added.

DETAILED DESCRIPTION

INTRODUCTION

The various aspects and embodiments described and claimed herein are described in further detail hereinbelow.

Priority US provisional application 61/998,637 filed July 3, 2014 is hereby incorporated by reference in its entirety for all purposes.

References cited herein are incorporated herein by reference.

In some embodiments described herein, the term "consisting

essentially of can be used in place of "comprising" when the composition or method, or element thereof, excludes components or process steps, respectively, which materially affect basic and novel features of the invention. In other embodiments described herein, the term "consisting of can be used in place of "comprising" when the composition or method, or element thereof, excludes components or process steps, respectively.

ALUMINUM COMPOSITION

First, as known in the art, aluminum can be a cation (3⁺) including wherein the aluminum is part of an aluminate anion, sometimes called a complex, represented by [AIX4]^" wherein X are anionic moieties such as halide, such as chloride or bromide, or fluorinated organic anion as described herein. The four anionic moieties X in the aluminate can be the same or different. In some cases, they are the same. In some cases, three are the same and one is different. An aluminate can form, for example, when an AIX₃ salt is mixed with an X^" anion, wherein again X may be the same or different. In some embodiments herein, however, the aluminum cation is not in aluminate form. In other embodiments herein, the aluminum cation is in aluminate form, or a mixture is present wherein some aluminum is in aluminate form, but other aluminum is not in aluminate form. Whether an aluminate forms can depend on at least the coordinating ability of the anion, as known in the art.

A first aspect is a composition which is an electrolyte and is

(I) [C⁺]aiAI³⁺]_b{[FOA-]₃}_c[Y-]_d

(II) [C⁺]_xAI(FOA^")₃(Y^")]_y[Y^"]_z

wherein C⁺ in Formulae (I) and (II) represents a cation other than aluminum; wherein FOA^" in Formulae (I) and (II) represents a fluorinated organic anion having molecular weight of 750 g/mol or less; wherein Y^" in Formulae (I) and (II) represents an anion which optionally may be a fluorinated organic anion having molecular weight of 750 g/mol or less represented by FOA^" or may be different; wherein Formula (I) is free of the aluminate anion; wherein in Formula (II) [AI(FOA^")₃(Y^")] represents an aluminate anion; wherein in Formula

(II) , subscripts x, y, and z are adapted for charge neutrality between the cation C+ and the aluminate anion [AI(FOA^")₃(Y^")] and Y^". For clarity, the [Y^"]₂ is not part of the aluminate anion. Also, x and y are non-zero but z can be zero or non-zero so Y^" is optional.

In one embodiment, the composition is the composition represented by Formula (I) but not Formula (II). In another embodiment, the composition is the composition represented by Formula (II) but not Formula (I). In still yet another embodiment, the composition is a mixture of compositions

represented by Formulae (I) and (II).

Such compositions can find a variety of uses including, for example, electrodeposition or electroplating, as well as electrochemical devices such as batteries and other applications described herein and known in the art for aluminum compounds and electrolytes.

For purposes herein, the terms "electrodeposition" and "electroplating" have the same meaning. Electroplating compositions for aluminum are known in the art. See, for example, Electrodeposition from Ionic Liquids, (Eds. Endres, MacFarlane, and Abbott, Eds.), Wiley-VCH, 2008. The composition can be adapted for electroplating by a variety of formulation methods and property considerations including, for example, selection of components including cations and anions, as well as selection of additives, selection of concentrations, purifications, selection of viscosity, selection of conductivity, selection of wetting agents, selection of brighteners, and other structural and property factors important to aluminum electroplating. The impact of formulation of the electroplating composition on the properties of the plated aluminum can also be examined, and important properties include, for example, adhesion to the substrate, micro- and nano-morphology, film thickness, smoothness, appearance, coherence, uniformity, profile, porosity, corrosion resistance, and the like. In addition, the electroplating conditions can also be considered such as, for example, bath temperature, maximum voltage, voltage profile, current density, anode quality, and substrate cleanliness. Other examples of adapting a composition for electroplating include formulating the composition for alloy deposition if desired. One or more additional metals besides aluminum can be present. Adapting the composition for electroplating is different from adapting the composition for other electrochemical uses such as batteries, as known in the art. Also, adapting the composition for an electrochemical use such as batteries is different from adapting the composition for electroplating, as known in the art.

In one embodiment, the electroplating composition comprises a mixture prepared from one or more components which include aluminum and a fluorinated organic component. For example, a salt can be used, and the aluminum is the cation, and the fluorinated organic moiety is the anion (e.g., AI(FOA)₃ wherein FOA is "fluorinated organic moiety"). As known in the art, an aluminum cation can coordinate with neutral or anionic ligands.

In particular, a second aspect is a composition which is an electrolyte and is prepared by mixing: (i) AI(FOA)₃, wherein FOA is a fluorinated organic anion having a molecular weight of less than 750 g/mol, with (ii) at least one additional salt component represented by [C⁺][Y^"]₍ wherein C⁺ represents a cation other than aluminum, and wherein Y^" in represents an anion which optionally may be a fluorinated organic anion having molecular weight of 750 g/mol or less represented by FOA^' or may be different. In some cases, an aluminate anion forms; in other cases, an aluminate anion does not form. The difference will depend on the ability of the anion Y^" to coordinate with Al as known in the art. One skilled in the art can vary the molar ratio of components (i) and (ii). In some cases, the molar amount of (ii) is higher than the molar amount of (i). For example, the molar ratio of (ii) to (i) can be, for example, at least 2:1 , or at least 5:1 , or at least 8:1. In other cases, the molar ratio can be about 1:1. In other embodiments, in the second aspect, the composition is prepared by mixing the additional salt component (ii) not with AI(FOA)₃ but rather with AI(FOA)2X or AI(FOA)X2, or combinations thereof, wherein X is a halide such as chloride or bromide. In general, a preference is present to use more FOA relative to halide as X and in the larger composition.

Fluorinated organic anionic moieties are known in the art. Non-limiting examples include triflate, trifluoroacetate, and fluorosulfonyl imide.

Fluorosulfonyl anions are particularly important as organic anions. In contrast, inorganic anions include borates (BX₄ ^") and phosphates (ΡΧε ), and

fluorinated inorganic anions include fluorinated borates or fluorinated

phosphates (X is F), which are not considered to be organic for purposes herein.

Hence, some embodiments include wherein the fluorinated organic anion is triflate, trifluoroacetate, or a bis(fluorosulfonyl)imide anion. Another embodiment includes wherein the fluorinated organic anion is a fluorosulfonyl anion. Other embodiments include wherein the fluorinated organic anion is a bis(fluorosulfonyl)imide anion. Still other embodiments include wherein the fluorinated organic anion is bis(trifluoromethylsulfonyl)imide anion. The fluorinated organic anion can include one or more perfluoro groups.

Fluorosulfonyl anions of various kinds are known in the art. They are characterized by one or more sulfonyl groups (-SO2-), as well as at least one fluoro moiety. The sulfonyl moiety can be bivalent; the fluoro moiety can be monovalent. Together, they can form the fluorosulfonyl anion. A fluoro moiety can be, for example, -F or also a monovalent fluorinated or

perfluorinated alkyl group such as, for example, -CF₃₎ -CH₂CF₃, -CF₂CF₃, - CF2CF2CF3, -CF2CF2CF₂CF_3l and the like. The fluorosulfonyl anion can be, for example, a Ci-C-i₂ monovalent moiety, or a C₂-C₆ monovalent moiety.

In some cases, the fluorosulfonyl is a fluorosulfonyl imide. In particular, the fluorosulfonyl anion can be, for example, an anionic imide moiety such as [N(fluorosulfonyl)2]^" as known in the art. Here, two fluorosulfonyl groups are covalently bonded to the imide nitrogen, in this embodiment. A lead example is the NTf2 moiety represented by [(CF₃S0₂)₂N]^".

The molecular weight of the fluorinated organic anionic moiety can be, for example, 750 g/mol or less, or 500 g/mol or less. No particular lower limit on molecular weight is present, or needs to be deduced, as long as the moiety is a fluorinated organic moiety, but the molecular weight of the fluorinated organic moiety can be greater than 100 g/mol, or greater than 200 g/mol. The fluorinated organic anion is not a macromolecule, not a high molecular weight polymer, and not a polyelectrolyte.

The anions are, of course, charge balanced with the cations in a neutral composition. The amounts of the anions and the cations can be adapted to reach charge neutrality including consideration whether the cation or anion is single charged or has a charge more than one (e.g., ⁺1 , ⁺2, ⁺3).

The selection of the C⁺ cation can be varied. In one embodiment, C⁺ is monovalent. In one embodiment, the cation C⁺ is an organic cation. Cations can be used which are useful, as known in the art, in forming ionic liquids, and a wide variety of cations with different substituents are known in the art for use in ionic liquids. In another embodiment, the cation C⁺ is an organic cation which comprises nitrogen in a heterocyclic ring or an organic cation which is an ammonium cation. In another embodiment, the cation C⁺ is, for example, an ammonium, pyrrolidinium, imidazolium, pyridinium, piperidinium, phosphonium, pyrazolium, or sulfonium cation. More particularly, the cation C⁺ is, for example, an ammonium cation. Ammonium cations are known in the art and include, for example, tetraalkylammonium cations (Ι¾Ν⁺, wherein the R's can be the same or different) such as, for example, tetrabutylammonium cation (R is butyl). In one embodiment, the cation C+ is not an imidazolium cation. The selection of the Y^" anion can be varied. In one embodiment, the Y^" anion is monovalent. For example, in one embodiment, the anion Y^" is a fluorinated organic anion, but in another embodiment, Y^" is not a fluorinated organic anion. In another embodiment, the anion is an inorganic anion such as, for example, a fluorinated borate (e.g., BF₄ ^") or a fluorinated phosphate anion (e.g., PF₆ ^"). In one embodiment, the anion Y^" is a halide such as fluoride, chloride, bromide, or iodide. However, in another embodiment, the anion Y^" is not a halide. In some embodiments, the anion Y^" is a

pseudohalide as known in the art.

Particular combinations of the cations and anions described herein can be used. For example, in one embodiment, the cation C⁺ is an ammonium cation and the anion Y^" is a fluorinated borate or a fluorinated phosphate anion. In another embodiment, Y^" is a fluorosulfonyl anion and FOA^" is also a fluorosulfonyl anion. Y^" is bis(trifluoromethylsulfonyl)imide anion and FOA^" is also bis(trifluoromethylsulfonyl)imide anion.

In Formulae (I) and (II), the values of a, b, c, and d, as well as x, y, and z are adapted for charge neutrality as known in the art. In a neutral compound or salt, the cationic charges need to equal the anionic charges. In most cases, the anion and cation are monovalent, apart from Al³⁺, and one skilled in the art can adapt a, b, c, and d, as well as x, y, and z to account for the charges on the anions and cations, e.g., any divalent or trivalent charges. Hence, for Formula I, the sum of cation subscripts a and b should equal the sum of anion subscripts c and d for overall charge neutrality. For Formula II, the sum of cation subscript x should equal the sum of anion subscripts y and z for overall charge neutrality. In one embodiment for Formula I, the value of a is higher than the value of b. In one embodiment for Formula I, the value of d is higher than the value of c. In one embodiment for Formula I, a can equal d, and b can equal c. The values of a, b, c, d, x, y, and z will change with the amounts of components mixed together as known in the art, and one skilled in the art can determine if a molar excess of molar deficiency of a particular component is desired.

Ionic liquids also can be used and formed. Ionic liquids are generally known in the art, and the aluminum compositions described herein can be or can include ionic liquids. Also, ionic liquids which are liquid at 25°C, or "room temperature ionic liquids," (RTILs) are generally known in the art. In some embodiments, the composition, whether an electroplating composition, a battery electrolyte composition, or a composition adapted for another use, is or comprises an ionic liquid.

As known in the art, whether the composition is an ionic liquid can be adapted by selection of cation and anion, as well as amounts of components. In some embodiments, the electroplating composition comprises at least one ionic liquid, wherein the cation of the ionic liquid is, for example, pyrrolidinium, imidazolium, pyridinium, piperidinium, phosphonium, pyrazolium, ammonium, sulfonium, and the like, as known in the ionic liquid arts. Other cations for ionic liquids are known and can be used.

In addition, the electroplating composition can comprise at least one solvent system. The solvent system can comprise one or more organic solvents including those having a relatively high polarity as reflected in a higher dielectric constant such as, for example 4 or more, or 8 or more. A protic, polar solvent(s) such as acetonitrile can be used. In preferred embodiments, the solvent system may also include some water as drying steps are minimized or avoided.

In sum, various preferred embodiments for the compositions, including electroplating compositions, include:

In one embodiment, the fluorinated organic anion is triflate,

trifluoroacetate, or a bis(fluorosulfonyl)imide anion. In another embodiment, the fluorinated organic anion is a bis(fluorosulfonyl)imide anion. In another embodiment,

the fluorinated organic anion is bis(trifluoromethylsulfonyl)imide anion.

In one embodiment, the composition, including an electroplating composition, is prepared with use of AI(NTf₂)3. The synthesis of this compound is known. See, for example, US Patent No. 6,998,497, col. 20, Example 28.

In some embodiments, the molar ratio of aluminum cation to fluorinated organic anion is equal to or less than 1 :1 , or equal to or less than 1 :2, or equal to or less than 1 :3, or equal to or less than 1 :4.

In some embodiments, the aluminum cation is not in the form of Al-X bonding wherein X is a halide. In some embodiments, the aluminum cation is not in the form of a haloaluminate. In some embodiments, the aluminum cation is not in the form of a chloroaluminate.

In some embodiments, the composition, including an electroplating composition, comprises at least one additional cation besides aluminum and at least one additional anion which is different than the organic fluorinated anion and is not an aluminate anion. In some embodiments, for example, the composition comprises at least one additional anion besides the organic fluorinated anion which is an inorganic anion. In some embodiments, for example, the composition comprises at least one additional anion besides the organic fluorinated anion which is a fluorinated inorganic anion. In some embodiments, the composition comprises at least one additional anion besides the organic fluorinated anion which is a borate or phosphate anion. In some embodiments, the composition comprises at least one additional anion besides the organic fluorinated anion which is tetrafluoroborate,

tetracyanoborate, hexafluorophosphate, or

tris(pentafluoroethyl)trifluorophosphate anion.

In some embodiments, the composition, including an electroplating composition, is an ionic liquid. In some embodiments, the composition is a room temperature ionic liquid. In some embodiments, the composition comprises at least one additional cation besides aluminum and at least one additional anion which is different than the organic fluorinated anion and is not an aluminate anion, wherein the additional cation and the additional anion form an ionic liquid when they are alone together. In some embodiments, the composition comprises at least one additional cation besides aluminum and at least one additional anion which is different than the organic fluorinated anion and is not an aluminate anion, wherein the additional cation and the additional anion form a room temperature ionic liquid when they are alone together. In some embodiments, the composition comprises at least one additional cation besides aluminum and at least one additional anion which is different than the organic fluorinated anion and is not an aluminate anion, wherein the additional cation and additional anion form an ionic liquid when they are alone together, and the additional cation is, for example, pyrrolidinium, imidazolium, pyridinium, piperidinium, phosphonium, pyrazolium, ammonium, sulfonium, and the like. In some embodiments, the composition, including electroplating composition, consists essentially of or even consists of (i) aluminum cation, and (ii) at least one anion which is a fluorinated organic anion having molecular weight of 750 g/mol or less.

In some embodiments, the composition, including electroplating composition, further comprises at least one solvent system comprising at least one organic solvent. In some embodiments, the electroplating composition further comprises at least one solvent system comprising at least one organic solvent having a dielectric constant greater than 4.

In some embodiments, the composition, including electroplating composition, further comprises at least one additive. Examples of additives include acid (e.g., para-toluene sulfonic acid) and brighteners such as, for example, sugars, glucose, sucrose, and saccharin.

In some embodiments, the composition, including electroplating composition, comprises at least 0.01 wt.% water, or at least 0.1 wt.% water, or at least 1 wt.% water, or even at least 5 wt.% water. No particular upper limit is present for water, but in the electroplating and electrochemical context, the amount of water will be limited. However, for commercial processes, it may be present as drying steps are minimized or avoided.

APPLICATIONS INCLUDING ALUMINUM ELECTROPLATING SYSTEM

The compositions can be used in a variety of applications. For example, electroplating and electrodeposition methods, apparatuses, devices, and systems, including deposition of aluminum, are generally known in the art. See, for example, Electrodeposition from Ionic Liquids, (Eds. Endres,

MacFarlane, and Abbott, Eds.), Wiley- VCH, 2008 including Chapters 4 and 12 and description for electrodeposition of aluminum. See also PhD thesis of E.M. Moustafa, 2007, Clausthal University of Technology ("Electroplating of Aluminum in Different Air and Water Stable Ionic Liquids"). Electroplating of aluminum is known to be a valid alternative for aluminum deposition

compared to other methods such as hot dipping, thermal spraying, sputter deposition, and vapor deposition.

Hence, a third aspect is a method comprising: providing at least one aluminum electroplating system comprising at least one substrate to be electroplated with aluminum; at least one electroplating composition which is adapted for electroplating aluminum onto the substrate; at least one counter electrode; and at least one electrical energy source to drive the electroplating; electroplating aluminum onto the substrate from the at least one electroplating composition, wherein the electroplating composition comprises: (i) aluminum cation, and (ii) at least one anion which is a fluorinated organic anion having molecular weight of 750 g/mol or less. The compositions described above in terms of Formulae (I) and (II) can be also used for electroplating composition.

Various embodiments for electrodeposition can be carried out. For example, in some cases, the ionic liquid might form a biphasic medium for deposition. In some case, microcrystalline or nanocrystalline metal, such as aluminum metal, may form in electrodeposition.

Electroplating conditions such as temperature, potential, time, purification of reagents and ionic liquids, and the like known in the art can be used. Temperatures known in the art can be used for electroplating. In one embodiment, for example, the metal, such as aluminum, is deposited at a temperature of 25°C to 150°C, or more preferably, 50°C to 100°C, or more preferably from 80°C to 100°C, or more preferably 85°C to 95°C.

Potentials known in the art for electroplating can be used, and the potential can be varied for the metal and the particular process. In one embodiment, the metal such as aluminum is deposited at a potential of about -1.9 V to -2.1 V, or about -2 V versus silver wire.

The substrate which is electroplated is not particularly limited but can be, for example, any conductive material including, for example, steel, Fe, Cu, Ni, Pt, Cu, brass, glassy carbon, and the like. The substrate can serve as the cathode, whereas the deposited metal such as aluminum can serve as the anode. In one embodiment, the substrate to be electroplated is not aluminum. In one embodiment, the substrate to be electroplated is not a battery electrode.

The thickness of the Al deposit is not particularly limited but can be adapted to the context and can be, for example, 0.5 microns to 500 microns, or 1 micron to 250 microns, or 5 microns to 100 microns.

Dense, adherent, uniform layers of aluminum layers, can be formed. In some embodiments, the electroplating is carried out with aluminum alone without another metal being electroplated. In other embodiments, the aluminum is electroplated together with at least one other metal. Alloys can be made including binary and ternary alloys. Aluminum can be alloyed with, for example, Nb, Ni, Co, Cr, Cu, Mn, La, Ag, Ti, Mo, Zr, Pt, and Mg. Ternary alloys can be made including, for example, Al-Mo-Mn and Al-Cr-Ni.

In sum, preferred embodiments include, for example:

In some embodiments, the electroplating is carried out under open environmental conditions. Minimal steps are taken to avoid water and/or oxygen and/or other impurities which can cost money to remove.

In some embodiments, the electroplating is carried out in an

electroplating bath and/or chamber, forming part of the electroplating system, under an electroplating atmosphere, and the electroplating atmosphere is not an inert gas atmosphere.

In some embodiments, the electroplating is carried out at a lower temperature, e.g., temperature of 20°C to 80°C.

In some embodiments, active steps can be taken to remove moisture from the electroplating system, whereas in other embodiments, which are preferred commercially, the need to remove moisture is eliminated or minimized because the electroplating is totally or substantially insensitive to moisture.

Even if water is controlled or minimized in electroplating, water can still be used in conventional steps before or after electrodeposition such as, for example, washing an electrode or washing a deposited metal.

In sum, one embodiment is a method comprising electroplating aluminum from an electroplating composition as described herein. In one embodiment, the electroplating composition comprises at least some measurable water, e.g., about 1 wt.% water or more.

The electroplated substrate can be subjected to further processes such as electrocoating or phosphating, such that there is deposition of more layers such as, for example, organic polymer coatings (e.g., a cationic epoxy electrocoat) or zinc phosphate coating.

Applications of electroplating of aluminum include imparting corrosion resistance to substrates such as steel. Steel fasteners such as bolts, for example, can be electroplated. Substrates can be flat, smooth, curved, or provide edges such as sharp edges.

ADDITIONAL EMBODIMENTS

Other applications can be carried out besides electroplating. For example, one embodiment is a method comprising completing an

electrochemical circuit with use of an electrolyte composition as described herein. The electrochemical circuit can be a battery electrochemical circuit, including an aluminum battery electrochemical circuit.

Devices can be provided which comprise a composition as described herein. For example, the device can be a battery, including an aluminum battery.

Additional embodiments include methods of use for a composition which comprises or is prepared from AI(FOA)₃, wherein FOA is a fluorinated organic anion having a molecular weight of less than 750 g/mol, and example being AI(NTf₂)3. Examples of methods of use include: a method comprising (i) catalyzing a polymerization reaction, (ii) catalyzing a Friedel-Crafts reaction, or (iii) sensing a target with use of a composition which comprises or is prepared from AI(FOA)₃, wherein FOA is a fluorinated organic anion having a molecular weight of less than 750 g/mol.

In one embodiment, the method comprises (i) catalyzing a

polymerization reaction but not (ii) catalyzing a Friedel-Crafts reaction or (iii) sensing a target. In another embodiment, the method comprises (ii)

catalyzing a Friedel-Crafts reaction but not (i) catalyzing a polymerization reaction or (iii) sensing a target.

In another embodiment, the method comprises (iii) sensing a target but not (i) catalyzing a polymerization reaction or (ii) catalyzing a Friedel-Crafts reaction.

In these embodiments, the FOA can be, for example, the

bis(trifluorosulfonyl)imide anion.

WORKING EXAMPLES

Additional embodiments are provided in the following non-limiting examples. Example 1 : Moisture Insensitivity Demonstrated

In one example, a solution containing 10mM of AI(NTf₂)3 in an acetonitrile solution with 0.1 M NBu PF₆ as a supporting electrolyte was prepared. In another example, the same solution was prepared but using 20mM of AI(NTf₂)₃ instead.

AI(NTf₂)3 was prepared by the following: 0.5 g AI₂(C0₃)₃ powder (2.13 mmol) was added directly to 1.80 g HNTf₂ powder (6.41 mmol) in a vial and stirred overnight under N₂ at 60°C. The resulting salt was washed with dichloromethane, ethanol and dried.

Cyclic voltammetry experiments were performed to measure the deposition potential for AI(NTf₂)₃ in the described system, and the results are illustrated in Figure 1. In these examples, the experimental setup included a 3mm glassy carbon working electrode, a platinum mesh counter electrode and a silver wire reference electrode; and scanning rate = 50mV/s. Standard pre-treatment procedures were as follows: all electrodes were polished using sand paper and cleaned using tissues; the electrodes where then degreased in acetone under ultrasonic conditions for 15 min. The electrodes were then rinsed thoroughly using deionized water prior to use. Although anhydrous acetonitrile was used and purged with dry N₂ prior to measurements, no special attention was paid to maintaining a water free environment during the experiment as the goal was to develop processes which have some moisture insensitivity.

Figure 1 shows initial voltammetry for the synthesized AI(NTf₂)₃ species with a clear reduction wave at about -1.8 V (vs. Ag wire). This reduction scales with increasing AI(NTf₂)₃ and is thus attributed to the reduction of this species. The anodic scan 'crossover' is indicative of a surface modification process being in effect with aluminum deposition highly likely. This

voltammetry also is generally water insensitive which provides for a robust, water insensitive method for aluminum electroplating.

Example 2: Impact of Water

Figure 2 is provided for further examining the impact of water in an experiments such as shown in Example 1. Figure 2 shows that explicitly added water, over that already present in non-dry acetonitrile, shows no essential change in the reduction profile (the small increase in peak height likely is due to either a solvation of the aluminum salt being favorable with a small amount of water additive or a change in viscosity or electrolyte dissociation).

Claims

WHAT IS CLAIMED IS:

1. A composition which is an electrolyte and is represented by the

composition of Formula (I), or a composition of Formula (II), or a composition representing a mixture of the compositions of Formulae (I) and (II), and optionally wherein the electrolyte composition has one or more additional components in the composition:

(I) [C⁺]a[AI³⁺]_b{[FOA¾}_c[Y-]_d

(II) [C⁺]x[AI(FOA-)₃(Y )]_y[Y-]₂

wherein C⁺ in Formulae (I) and (II) represents a cation other than aluminum;

wherein FOA^" in Formulae (I) and (II) represents a fluorinated organic anion having molecular weight of 750 g/mol or less;

wherein Y^" in Formulae (I) and (II) represents an anion which optionally may be a fluorinated organic anion having molecular weight of 750 g/mol or less represented by FOA^" or may be different;

wherein Formula (I) is free of the aluminate anion;

wherein in Formula (II) [AI(FOA^")₃(Y^")] represents an aluminate anion; wherein in Formula (I), subscripts a, b, c, and d are non-zero and adapted for charge neutrality between cations C⁺ and Al³⁺ and anions FOA^" and Y^"; and

wherein in Formula (II), subscripts x, y, and z are adapted for charge neutrality between the cation C+ and the aluminate anion [AI(FOA^")₃(Y^")] and Y^", and x and y are non-zero but z can be zero or non-zero.

2. The composition of claim 1 , wherein the composition is the composition represented by Formula (I) but not Formula (II).

3. The composition of claim 1 , wherein the composition is the composition represented by Formula (II) but not Formula (I).

4. A composition which is an electrolyte and is prepared by mixing:

(i) AI(FOA)₃, wherein FOA is a fluorinated organic anion having a molecular weight of less than 750 g/mol, with (ii) at least one additional salt component represented by [C⁺][Y^"], wherein C⁺ represents a cation other than aluminum, and wherein Y^" represents an anion which optionally may be a fluorinated organic anion having molecular weight of 750 g/mol or less represented by FOAor may be different.

5. The composition of claims 1-4, wherein the fluorinated organic anion is triflate, trifluoroacetate, or a bis(fluorosulfonyl)imide anion.

6. The composition of claims 1-5, wherein the fluorinated organic anion is a bis(fluorosulfonyl)imide anion.

7. The composition of claims 1-6, wherein the fluorinated organic anion is bis(trifluoromethylsulfonyl)imide anion.

8. The composition of claims 1-7, wherein the cation C⁺ is an organic cation.

9. The composition of claims 1-8, wherein the cation C⁺ is an organic cation which comprises nitrogen in a heterocyclic ring or an organic cation which is an ammonium cation.

10. The composition of claims 1-9, wherein the cation C⁺ is an ammonium, pyrrolidinium, imidazolium, pyridinium, piperidinium, phosphonium, pyrazolium, or sulfonium cation.

11. The composition of claims 1-10, wherein the cation C⁺ is an ammonium cation.

12. The composition of claims 1-9, wherein the cation C+ is not an

imidazolium cation.

13. The composition of claims 1-12, wherein the anion Y^" is a fluorinated organic anion (FOA^").

14. The composition of claims 1-12, wherein the anion Y^" is a fluorinated borate or a fluorinated phosphate anion.

15. The composition of claims 1-12, wherein the anion Y^" is a halide.

16. The composition of claims 1-14, wherein the anion Y^" is not a halide.

17. The composition of claims 1-12, 14, and 16, wherein the cation C⁺ is an ammonium cation and the anion Y^" is a fluorinated borate or a fluorinated phosphate anion.

18. The composition of claims 1-13, and 16, wherein Y^" is

bis(trifluoromethylsulfonyl)imide anion and FOA^" is

bis(trifluoromethylsulfonyl)imide anion.

19. The composition of claims 1-18, wherein the composition is an ionic liquid.

20. The composition of claims 1-19, wherein the composition is a room temperature ionic liquid. ,

21. A method comprising electroplating aluminum from an electroplating composition according to claims 1-20.

22. The method of claim 21 , wherein the electroplating composition

comprises at least 1 wt.% water.

23. The method of claims 21-22, wherein the electroplating of aluminum is an electroplating of aluminum alloy.

24. The method of claims 21-23, wherein the electroplating composition comprises at least one organic solvent.

25. The method of claims 21-24, wherein the electroplating composition comprises at least one additive.

26. A method comprising completing an electrochemical circuit with use of an electrolyte composition according to claims 1-20.

27. A method comprising completing a battery electrochemical circuit with use of an electrolyte composition according to claims 1-20.

28. A device comprising the composition according to claims 1-20.

29. The device of claim 28, wherein the device is a battery comprising an electrolyte according to claims 1-20.

30. The device of claim 29, wherein the device is an aluminum battery.

31. A method comprising:

providing at least one aluminum electroplating system comprising at least one substrate to be electroplated with aluminum; at least one

electroplating composition which is adapted for electroplating aluminum onto the substrate; at least one counter electrode; and at least one electrical energy source to drive the electroplating;

32. The method of claim 31 , wherein the aluminum cation is not in aluminate form.

33. The method of claim 31 , wherein the aluminum cation is in aluminate form.

34. The method of claims 31-33, wherein the fluorinated organic anion is triflate, trifluoroacetate, or a bis(fluorosulfonyl)imide anion.

35. The method of claims 31-34, wherein the fluorinated organic anion is a bis(fluorosulfonyl)imide anion.

36. The method of claims 31-35, wherein the fluorinated organic anion is bis(trifluoromethylsulfonyl)imide anion.

37. The method of claims 31-36, wherein the electroplating composition is prepared with use of AI(NTf₂)3.

38. The method of claims 31-37, wherein the molar ratio of aluminum cation to fluorinated organic anion is equal to or less than 1 :1.

39. The method of claims 31-37, wherein the molar ratio of aluminum cation to fluorinated organic anion is equal to or less than 1 :3.

40. The method of claims 31-39, wherein the aluminum cation is not in the form of Al-X bonding wherein X is a halide.

41. The method of claims 31-40, wherein the aluminum cation is not in the form of a haloaluminate.

42. The method of claims 31-40, wherein the aluminum cation is not in the form of a chloroaluminate.

43. The method of claims 31-42, wherein the electroplating composition comprises at least one additional cation besides aluminum and at least one additional anion which is different than the organic fluorinated anion and is not an aluminate anion.

44. The method of claims 31-43, wherein the electroplating composition comprises at least one additional anion besides the organic fluorinated anion which is an inorganic anion.

45. The method of claims 31-44, wherein the electroplating composition comprises at least one additional anion besides the organic fluorinated anion which is a fluorinated inorganic anion.

46. The method of claims 31-45, wherein the electroplating composition comprises at least one additional anion besides the organic fluorinated anion which is a borate or phosphate anion.

47. The method of claims 31-46, wherein the electroplating composition is an ionic liquid.

48. The method of claims 31-47, wherein the electroplating composition is a room temperature ionic liquid.

49. The method of claims 31-48, wherein the electroplating composition comprises at least 1 wt.% water.

50. The method of claims 31-49, wherein the electroplating is carried out under open environmental conditions.

51. A method comprising (i) catalyzing a polymerization reaction, (ii) catalyzing a Friedel-Crafts reaction, or (iii) sensing a target with use of a composition which comprises or is prepared from AI(FOA)₃, wherein FOA is a fluorinated organic anion having a molecular weight of less than 750 g/mol.

52. The method of claim 51 comprising (i) catalyzing a polymerization reaction but not (ii) catalyzing a Friedel-Crafts reaction or (iii) sensing a target.

53. The method of claim 51 comprising (ii) catalyzing a Friedel-Crafts reaction but not (i) catalyzing a polymerization reaction or (iii) sensing a target.

54. The method of claim 51 comprising (iii) sensing a target but not (i) catalyzing a polymerization reaction or (ii) catalyzing a Friedel-Crafts reaction.

55. The method of claims 51-54, wherein FOA is bis(trifluorosulfonyl)imide anion.