Dry dispersions of ammonium bis(fluorosulfonyl)imide (NH4FSI) salts with at least bimodal particle size distributions.

Abstract

The present disclosure relates to a compound of formula (I): [F-SO2-N - -SO2-F],NH4 + The present disclosure relates to a dry dispersion of an ammonium bis(fluorosulfonyl)imide (NHFSI) salt of (I), characterized by having at least two particle size fractions, a small size fraction and a large size fraction. The present disclosure also relates to the use of such a dispersion for preparing a salt of the bis(fluorosulfonyl)imide selected from the group consisting of lithium, sodium or potassium salts.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED PATENT APPLICATIONS This application claims priority to European Patent Application No. 21315245.7, filed November 19, 2021, the entire contents of which are incorporated herein by reference for all purposes.

[0002] The present disclosure provides a compound of formula (I): [F-SO2-N - -SO2-F],NH4 + (I) The present disclosure relates to a dry dispersion of an ammonium bis(fluorosulfonyl)imide (NHFSI) salt of the formula: wherein the dry dispersion is characterized by having at least two particle size fractions, a small size fraction and a large size fraction. The present disclosure also relates to the use of such a dispersion for preparing a salt of the bis(fluorosulfonyl)imide selected from the group consisting of lithium, sodium or potassium salts. [Background technology]

[0003] Bis(fluorosulfonyl)imides and their salts, in particular the lithium salt of bis(fluorosulfonyl)imide (LiFSI), are compounds that are useful in a variety of technical fields, particularly in the field of battery electrolytes.

[0004] The preparation of bis(fluorosulfonyl)imide (FSI) and its salts has been described in the literature. One of the intermediates that can give rise to the FSI salt of interest is ammonium bis(fluorosulfonyl)imide (NH4FSI). For example, WO 2017 / 090877A1 (CLS) describes a method for preparing lithium bis(fluorosulfonyl)imide, which includes (1) reacting bis(chlorosulfonyl)imide with a fluorinating agent in a solvent, followed by treatment with an alkaline agent to produce NH4FSI, and (2) reacting NH4FSI with a lithium base.

[0005] Because intermediates such as NH4FSI salts are involved in subsequent manufacturing steps and may need to be transported from one part of the plant to another, it is convenient to have them in the form of a dry dispersion or powder.

[0006] WO 2018 / 147195 A1 (Morita and Nippon Shokubai Co., Ltd.) relates to dry powders of bis(fluorosulfonyl)imide metal salts having a particle size of 0.2 mm or more. It also relates to a method for preparing such powders, which includes shaping the salt in a molten state. The powder is heated and melted to a molten state and then shaped using any available method, including dry and wet processes (drum flake granulation, casting, roll drop steel belt granulation, prilling tower granulation, melt crystallization, etc.).

[0007] US Patent Application Publication No. 2016 / 0289074A1 (Nippon Soda Co., Ltd.) relates to granules or powders of di(sulfonylamide) salts, such as di(sulfonylamide) alkali metal salts or di(sulfonylamide) ammonium salts. The granules or powders in this document are represented by the formula [I]: [ka] (In the formula, R 1 and R 2 each independently represents a fluoroalkyl group having 1 to 6 carbon atoms or a fluorine atom; Y + represents an alkali metal cation or an ammonium cation) The granules have a mode diameter of less than 80 μm and a median diameter of less than 45 μm, for example, between 5 and 45 μm.

[0008] US Patent Application Publication No. 2019 / 0276311A1 (Nippon Shokubai Co., Ltd.) relates to a method for producing FSI metal salt, which comprises reacting bis(fluorosulfonyl)imide (HFSI) with an alkali metal halide in a reaction solution containing an organic solvent, and purifying the FSI salt obtained by filtering the resulting FSI salt. The filtering is preferably performed by using a filter medium having a retention particle size of 0.1 to 10 μm.

[0009] None of these documents describes the NH4FSI salt dispersion of the present invention having at least two particle size fractions and therefore suitable flowability and solubility in various solvents for storage and use in subsequent manufacturing processes. Summary of the Invention

[0010] The present invention relates to a compound of formula (I): [F-SO2-N - -SO2-F],NH4 + (I) wherein the NH4FSI salt is optionally a dry dispersion of - 50 to 99.9% by weight of NH4FSI salt; - 0.1 to 50% by weight of a solvent S2 selected from the group consisting of cyclic and acyclic ethers, and the dry dispersion relates to a dry dispersion comprising at least two particle size fractions, namely a small size fraction and a large size fraction.

[0011] The present invention relates to a compound of formula (II): [F-SO2-N - -SO2-F],M + (II) (wherein M is selected from the group consisting of Li, Na and K). The present invention also relates to a process for preparing the ammonium bis(fluorosulfonyl)imide (NHFSI) salt of formula (I) as described herein, comprising reacting a dry dispersion of the ammonium bis(fluorosulfonyl)imide (NHFSI) salt of formula (I) as described herein with a compound (C) selected from the group consisting of lithium compounds, sodium compounds and potassium compounds.

[0012] Another aspect of the present invention is a compound of formula (II): [F-SO2-N - -SO2-F],M + (II) (wherein M is selected from the group consisting of Li, Na and K). A dry dispersion of a bis(fluorosulfonyl)imide (MFSI) salt of the formula: wherein the dry dispersion comprises at least two particle size fractions. Such a dispersion may be obtained from the process described herein. [Brief description of the drawings]

[0013] [Figure 1] The bimodal particle size distribution (PSD) of the dry dispersion is shown. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] In this application: - any description, even if made in relation to a particular embodiment, is applicable and interchangeable with other embodiments of the invention; - when an element or component is said to be included in and / or selected from a list of enumerated elements or components, in the relevant embodiments expressly contemplated herein, it is to be understood that the element or component may be any one of the individual enumerated elements or components, or may also be selected from a group consisting of any two or more of the explicitly enumerated elements or components, and that any element or component enumerated in a list of elements or components may be omitted from such list; - Any recitation herein of numerical ranges by endpoints includes all numbers subsumed within the recited range, as well as the endpoints of the range and equivalents thereof.

[0015] The dry dispersions of ammonium bis(fluorosulfonyl)imide (NHFSI) salts of the present invention are characterized as comprising at least two particle size fractions, a small size fraction and a large size fraction. The dispersions of the present invention may comprise more than two fractions. Preferably, the dispersions of the present invention are characterized by a bimodal particle size distribution. The fractions are characterized by various particle size distribution (PSD) parameters, such as d 50 It can be characterized by the value of d, also called D50 50 The value is also known as the median size or median value of the PSD. It is the value of the particle size at 50% of the cumulative distribution. It is the value at which 50% of the particles in the sample by volume are d 50 value, and 50% by volume of the particles in the sample are greater than d 50 It means less than the value.

[0016] In some preferred embodiments, the small size fraction has a d of less than 120 μm, e.g., less than 115 μm, less than 110 μm, less than 105 μm, or less than 100 μm, as determined by laser diffraction in n-hexane. 50 It has a value.

[0017] The small size fraction is - That d 10 and / or - That d 50 The value may be such that it is 80 to 115 μm, preferably 85 to 110 μm, and more preferably 90 to 105 μm.

[0018] In some further preferred embodiments, the large size fraction has a d of greater than 200 μm, greater than 210 μm, greater than 220 μm, or even greater than 230 μm as determined by laser diffraction in n-hexane. 50It has a value.

[0019] The large size fraction is - That d 50 The value is 200 to 250 μm, preferably 205 to 245 μm, and more preferably 210 to 240 μm. - That d 90 and / or - That d 99 The value may be such that it is 300 to 400 μm, preferably 310 to 380 μm.

[0020] The volume ratio of small to large particles can be 5:95 to 95:5, 10:90 to 90:10, or 20:80 to 80:20. The volume ratio can be determined, for example, by software calculation using SYMPATEC®.

[0021] The PSD of the dry dispersion of the present invention, as determined by laser diffraction in n-hexane, is preferably: - That d 10 The value is 20 μm or more, preferably 30 to 100 μm, more preferably 40 to 95 μm, and even more preferably 60 to 90 μm, - That d 50 The value is 140 to 190 μm, preferably 145 to 185 μm, and more preferably 150 to 180 μm, - That d 90 and / or - That d 99 The value may be such that it is 300 to 400 μm, preferably 310 to 380 μm.

[0022] In some embodiments, the aspect ratio of the dry dispersion, defined as the average ratio of the minimum Feret length to the maximum Feret length counted for about 60 particles from a scanning electron microscope (SEM) image, is in the range of 0.3 to 1.0, preferably 0.5 to 0.95, and even more preferably 0.7 to 0.9.

[0023] The small and large size fractions of the present invention may also be characterized by the particle diameter at the peak of the volume-based particle size distribution, Dp.

[0024] In some embodiments, the particle size Dp at the peak of the small size fraction is 80 to 115 μm, preferably 85 to 110 μm, and more preferably 90 to 105 μm.

[0025] In some embodiments, the particle size Dp at the peak of the large size fraction is 200 to 250 μm, preferably 205 to 245 μm, and more preferably 210 to 240 μm.

[0026] The dispersion of the present invention may be such that it has at least one shape selected from the group consisting of tetragonal, monoclinic, spherical, rod-like, needle-like and mixtures thereof.Preferably, it has at least two shapes selected from the group consisting of tetragonal, monoclinic, spherical, rod-like, needle-like and mixtures thereof.

[0027] In some embodiments, the dispersion comprises: - Small fraction F s is rod-shaped and / or needle-shaped, and - Large fraction F L has a shape such that it is a tetragonal shape, a monoclinic shape and / or a spherical shape, the small fraction being less than 50% by weight and the large fraction being more than 50% by weight; s +F L The sum of these is equal to 100% by weight.

[0028] In some embodiments, the NH4FSI salt in the dispersion is - 50 to 99.9% by weight of NH4FSI salt; - 0.1 to 50% by weight of a solvent S2 selected from the group consisting of cyclic and acyclic ethers, embedded image In the form of a solvate, optionally in crystalline form, comprising:

[0029] In some embodiments, the NH4FSI salt in the dispersion may be a solvate containing 50-99.5 wt%, 50-99 wt%, or 50-98 wt% of the NH4FSI salt. The NH4FSI salt in the dispersion may be a solvate containing 50.5-99.9 wt%, 51-99 wt%, or 52-98 wt% of the NH4FSI salt. The NH4FSI salt in the dispersion may further be a solvate containing 55-95 wt%, 60-90 wt%, or 63-83 wt% of the NH4FSI salt.

[0030] In some embodiments, the NH4FSI salt in the dispersion may be a solvate containing 0.1 to 49.5 wt%, 0.1 to 49 wt%, or 0.1 to 48 wt% of solvent S2. The NH4FSI salt in the dispersion may be a solvate containing 0.5 to 50 wt%, 1 to 50 wt%, or 2 to 50 wt% of solvent S2. The NH4FSI salt in the dispersion may further be a solvate containing 5 to 45 wt%, 10 to 40 wt%, or 17 to 37 wt% of solvent S2.

[0031] The dry dispersion of the present invention is i) providing a crude salt of NH4FSI; ii) dissolving the crude salt of NH4FSI in at least one solvent S1; iii) crystallizing the crude salt of NH4FSI from at least one solvent S2; and iv) separating the NH4FSI salt from at least a portion of the solvents S1 and S2, preferably by filtration. The crude salt of NH4FSI may contain 80 to 97% by weight, preferably 85 to 95% by weight, more preferably 90 to 95% by weight of the salt of NH4FSI. The crude salt of NH4FSI may contain 80 to 97% by weight, preferably 85 to 95% by weight, more preferably 90 to 95% by weight of the salt of NH4FSI. - , F - , ClO- , SO4 2- , NH2SO3 - , and impurities such as NH4[N(SO3H)(SO2F)](OFSI) and / or NH4[N(SO3H)2](OSI).

[0032] The weight content of these impurities may vary from 3 to 20% by weight, for example from 5 to 15% by weight or from 10 to 5% by weight.

[0033] In some embodiments, solvent S1 is selected from the group consisting of acetonitrile, valeronitrile, adiponitrile, benzonitrile, methanol, ethanol, 1-propanol, 2-propanol, 2,2,2-trifluoroethanol, n-butyl acetate, isopropyl acetate, and mixtures thereof, preferably 2,2,2-trifluoroethanol (TFE).

[0034] In some further embodiments, solvent S2 is selected from the group consisting of diethyl ether, diisopropyl ether, methyl-t-butyl ether, dimethoxymethane, 1,2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, 1,3-dioxane, 4-methyl-1,3-dioxane and 1,4-dioxane and mixtures thereof, more preferably from the list consisting of diethyl ether, diisopropyl ether, methyl t-butyl ether, 1,2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, dioxane and mixtures thereof, even more preferably 1,3-dioxane or 1,4-dioxane.

[0035] In a preferred embodiment, the dry dispersion is in the form of an at least partially crystallized solvate comprising 0.1% to 50% by weight of solvent S2 (preferably dioxane) and 50 to 99.9% by weight of NH4FSI salt, such dispersion comprising: i) providing a crude salt of NH4FSI; ii) dissolving the crude salt of NH4FSI in at least one solvent S1 (preferably TFE); iii) crystallizing the crude salt of NH4FSI from at least one solvent S2, preferably dioxane; and iv) separating the NH4FSI salt from at least a portion of the solvents S1 and S2, preferably by filtration. The method is obtained by a process including:

[0036] In some embodiments, the weight ratio of S1 / S2 in the process of preparing the dispersion of the present invention varies from 1 / 10 to 10 / 1, preferably from 1 / 5 to 5 / 1, more preferably from 1 / 2 to 2 / 1.

[0037] The present invention relates to a compound of formula (II): [F-SO2-N - -SO2-F],M + (II) (wherein M is selected from the group consisting of Li, Na and K). The present invention also relates to a process for preparing the ammonium bis(fluorosulfonyl)imide (MFSI) salt of formula (I) comprising reacting a dry dispersion of the ammonium bis(fluorosulfonyl)imide (NHFSI) salt of formula (I) as described herein with a compound (C) selected from the group consisting of lithium compounds, sodium compounds and potassium compounds.

[0038] In some embodiments, compound (C) is preferably a lithium compound selected from the group consisting of lithium hydroxide LiOH, lithium hydroxide hydrate LiOH.H2O, lithium carbonate Li2CO3, lithium bicarbonate LiHCO3, lithium chloride LiCl, lithium fluoride LiF, alkoxide compounds such as CHOLi and EtOLi, alkyl lithium compounds such as EtLi, BuLi and t-BuLi, lithium acetate CH3COOLi and lithium oxalate Li2C2O4, more preferably LiOH.H2O or Li2CO3.

[0039] The present invention relates to a compound of formula (II): [F-SO2-N - -SO2-F],M + (II) (wherein M is selected from the group consisting of Li, Na and K). The present invention also relates to a dry dispersion of a bis(fluorosulfonyl)imide (MFSI) salt of the formula (I) comprising at least two particle size fractions.

[0040] The dry dispersion of the MFSI salt can be obtained from the process described above.

[0041] The MFSI salt described herein is preferably LiFSI.

[0042] In some embodiments, the dry dispersion of the MFSI salt contains at least 1 ppm of solvent S2. The dry dispersion of the MFSI salt may contain, for example, 1 to 100 ppm of solvent S2, 2 to 80 ppm, 3 to 60 ppm, 4 to 40 ppm, or 5 to 25 ppm of solvent S2.

[0043] To the extent that the disclosures of any patents, patent applications, and publications incorporated herein by reference conflict with the statements of this application to the extent that any term may be unclear, the statements of this application shall control.

[0044] The present disclosure will now be described in more detail with reference to the following examples, the purpose of which is merely illustrative and is not intended to limit the scope of the present disclosure. EXAMPLES

[0045] The PSD of two dispersions of FSI salts were analyzed: the first was a dispersion of NHFSI salt according to the invention (Powder #1), and the second was a dispersion of LiFSI salt (Powder #2), commercially available from Nippon Shokubai Co., Ltd. under the trademark IONEL®.

[0046] Powder #1 - Dispersion of NH4FSI in the form of a solvate The dispersion of the invention was prepared according to the following process: A 500 mL reactor was used, equipped with stirring means, a double jacket for heat regulation, a condenser, pressure regulation means and means for adding liquids or gases. 400 g of ethyl methyl carbonate (EMC) were introduced into the reactor at room temperature. 81 g of anhydrous NH4F were suspended in the reactor. 77 g of molten HCSI were then gradually added during 1 hour and the mixture was heated at 80° C. with stirring for 15 hours. The reaction mixture was then cooled to room temperature and 25 g of NH4OH(aq) (aqueous ammonia) were added. The reaction mixture containing the NH4FSI salt was stirred at room temperature for 1 hour and then filtered.

[0047] 332 g of this crude NH4FSI was concentrated to 48 g. 300 g of 2,2,2-trifluoroethanol (TFE) was added to the solution and concentrated to 170 g of solution. This operation was repeated twice. 170 g of the solution was then transferred to a three-neck flask. Proper stirring and temperature were set to ensure complete dissolution of NH4FSI in TFE. 139.5 g of 1,4-dioxane was then added dropwise to the reactor over a period of 3 hours. After the addition of 1,4-dioxane was completed, the solution temperature was maintained at 60° C. for an additional 2 hours. The mixture was then allowed to cool to room temperature overnight with stirring. The contents of the flask were then filtered using a 0.22 μm PTFE membrane to recover the solid NH4FSI. The recovered solid cake was washed with 60 g of 1,4-dioxane. The collected solid was dried using a rotary evaporator at 70° C. and 20 mbar until no more solvent evaporated, yielding 28.8 g of a white solid, which is a crystallized solvate of NH4FSI containing 80% by weight of NH4FSI and 20% by weight of 1,4-dioxane (NH4FSI-S).

[0048] The recrystallization yield calculated by the following formula is 48%.

number

[0049] Test Method PSD The PSD was determined by laser diffraction (HELOS CUVETTE). The diffraction information (raw data) was converted to cumulative distribution and normalized differential distribution by SYMPATEC® software provided by the instrument manufacturer. Meanwhile, the samples were prepared in a glove box. 0.1 mg of solid sample was dispersed in 2.5 mL of n-hexane to give a final particle mass fraction of about 4%.

[0050] shape The particle morphology of the solid samples was analyzed by optical microscopy (bright field). Samples were prepared in a glove box. 0.1 mg of solid sample was mixed with paraffin on a glass slide, covered with a cover slip, and then sealed by UV curing.

[0051] result Powder #1 FIG. 1 shows the bimodal particle size distribution (PSD) of the dry dispersion.

[0052] [Table 1]

[0053] Volume ratio of small particles to large particles: 1 / 1

[0054] The particle morphology consisted of mostly quadrangular, monoclinic and spherical particles with a small amount of rod-like and needle-like particles.

[0055] Powder #2

[0056] [Table 2]

Claims

1. Formula (I): [F-SO ２ -N － -SO ２ -F],NH ４ ＋ (I) Ammonium bis(fluorosulfonyl)imide (NH ４ a dry dispersion of NH FSI salt, ４ The FSI salt may optionally be: - 50 to 99.9% by weight of said NH ４ FSI salt, - 0.1 to 50% by weight of a solvent S selected from the group consisting of cyclic and acyclic ethers ２ and wherein the dry dispersion comprises at least two particle size fractions, a small size fraction and a large size fraction.

2. As determined by laser diffraction in n-hexane: - said small size fraction is a d less than 120 μm ５０ has a value, - the large size fraction is greater than 200 μm ５０ and / or A dispersion according to claim 1, in which the volume ratio of small particles to large particles is between 5:95 and 95:

5.

3. As determined by laser diffraction in n-hexane: - That d １０ The value is 20 μm or more, preferably 30 to 100 μm, - That d ５０ a value of 140 to 190 μm, preferably 145 to 185 μm; - That d ９０ a value of 260 to 300 μm, preferably 265 to 290 μm, and / or - That d ９９ 2. The dispersion according to claim 1, wherein the value is between 300 and 400 μm, preferably between 310 and 380 μm.

4. The small size fraction of the dried dispersion, as determined by laser diffraction in n-hexane, is - That d １０ a value of 20 μm or more, preferably 30 to 100 μm, and / or - That d ５０ 2. The dispersion of claim 1, wherein the value is between 80 and 115 μm.

5. The large size fraction of the dried dispersion, as determined by laser diffraction in n-hexane, is - That d ５０ value is 200 to 250 μm, - That d ９０ and / or - That d ９９ 2. The dispersion of claim 1, wherein the value is between 300 and 400 μm.

6. 10. The dispersion of claim 1, having a shape that is at least one selected from the group consisting of tetragonal shapes, monoclinic shapes, spherical shapes, rod shapes, needle shapes, and mixtures thereof.

7. 7. The dispersion of claim 6, having shapes that are at least two selected from the group consisting of tetragonal shapes, monoclinic shapes, spherical shapes, rod shapes, needle shapes, and mixtures thereof.

8. - Subfraction F ｓ is rod-shaped and / or needle-shaped, and - Large fraction F Ｌ is a tetragonal, monoclinic and / or spherical shape, the small fraction being less than 50% by weight and the large fraction being more than 50% by weight, F ｓ +F Ｌ The dispersion of claim 6, wherein the sum of is equal to 100% by weight.

9. Said NH ４ The FSI salt is dissolved in a solvent S selected from the group consisting of diethyl ether, diisopropyl ether, methyl t-butyl ether, dimethoxymethane, 1,2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, 1,3-dioxane, 4-methyl-1,3-dioxane and 1,4-dioxane and mixtures thereof, more preferably from the list consisting of diethyl ether, diisopropyl ether, methyl t-butyl ether, 1,2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, dioxane and mixtures thereof, even more preferably 1,3-dioxane or 1,4-dioxane. ２ 2. The dispersion of claim 1, which is a solvate comprising:

10. 10. A process for preparing the dispersion of claim 1, comprising: i) NH ４ providing a crude salt of FSI; ii) The NH ４ The crude salt of FSI is dissolved in at least one solvent S １ dissolving in iii) at least one solvent S ２ Thus, the NH ４ Crystallizing the crude salt of FSI; and iv) the solvent S １ and S ２ from at least a portion of the NH ４ Separating the FSI salt A process involving:

11. - S １ is selected from the group consisting of acetonitrile, valeronitrile, adiponitrile, benzonitrile, methanol, ethanol, 1-propanol, 2-propanol, 2,2,2-trifluoroethanol, n-butyl acetate, isopropyl acetate, and mixtures thereof; - S ２ is selected from the group consisting of diethyl ether, diisopropyl ether, methyl t-butyl ether, dimethoxymethane, 1,2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, 1,3-dioxane, 4-methyl-1,3-dioxane and 1,4-dioxane, and mixtures thereof; and / or - S １ / S ２ The process of claim 10, wherein the weight ratio of varies from 1 / 10 to 10 / 1.

12. Formula (II): [F-SO ２ -N － -SO ２ -F],M ＋ (II) wherein M is selected from the group consisting of Li, Na, and K.

2. A process for preparing the bis(fluorosulfonyl)imide (MFSI) salt of formula (I) according to claim 1, comprising the steps of: ４ 1. A process comprising reacting a dry dispersion of a fluorine-containing fluoride (FSI) salt with a compound (C) selected from the group consisting of lithium compounds, sodium compounds and potassium compounds.

13. The compound (C) is preferably lithium hydroxide LiOH, lithium hydroxide hydrate LiOH.H ２ O, Lithium carbonate Li ２ CO ３ , lithium bicarbonate LiHCO ３ , lithium chloride LiCl, lithium fluoride LiF, CH ３ Alkoxide compounds such as OLi and EtOLi, alkyllithium compounds such as EtLi, BuLi and t-BuLi, lithium acetate CH ３ COOLi and lithium oxalate Li ２ C ２ O ４ , more preferably LiOH.H ２ O or Li ２ CO ３ 13. The process of claim 12, wherein the lithium compound is selected from the group consisting of:

14. Formula (II): [F-SO ２ -N － -SO ２ -F],M ＋ (II) wherein M is selected from the group consisting of Li, Na, and K.

1. A dry dispersion of a bis(fluorosulfonyl)imide (MFSI) salt of the formula:

15. - obtainable from a process according to any one of claims 11 to 13, and / or - at least 1 ppm of solvent S ２ The dispersion of claim 14 comprising:

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