Process for the production of bis (halosulfonyl) imides

Abstract

The present invention relates to a novel synthetic route for the manufacture of bis (halosulfonyl) imides, which are useful intermediates in the synthesis of lithium bis (fluorosulfonyl) imides (LiFSI).

Description

[0001] Cross-references to related patent applications

[0002] This application claims priority from European application number 22306396.7 filed on September 22, 2022, the entire contents of which are incorporated by reference into this application for all purposes. Technical Field

[0003] The present invention relates to a novel synthetic route for the preparation of bis(halosulfonyl)imines, which are useful intermediates for the synthesis of lithium bis(fluorosulfonyl)imide (LiFSI). Background Art

[0004] Bis(fluorosulfonyl)imide and its salts, in particular the lithium salt of bis(fluorosulfonyl)imide (LiFSI), are useful compounds in various technical fields, including in battery electrolytes.

[0005] Several methods for making LiFSI have been described in the art. Among the different techniques described, most use a fluorination reaction with a fluorinating agent in a solvent.

[0006] Many efforts have also been made in the art to improve the manufacturing methods of intermediate compounds that produce LiFSI, especially in terms of purity, yield and cost reduction.

[0007] US2014 / 0075746 (in the name of Arkema France) discloses a method for preparing a bis(sulfonate)imide salt having the formula:

[0008] (III)(SO3 - )-N - -(SO3 - )3C +

[0009] Among them C + represents a monovalent cation,

[0010] The method comprises making an amino-sulfonic acid having the formula:

[0011] (I) HO-SO2-NH2

[0012] Reaction with a halo-sulfonic acid having the formula:

[0013] (II)HO-SO2-X

[0014] Wherein X represents a halogen atom,

[0015] And the method comprises reacting with a base, the base being a + The salt formed.

[0016] According to an embodiment of such a method, the reaction between compounds of formula (I) and (II) is carried out in the presence of a first base to provide a bis(sulfonyl)imide having the formula:

[0017] (IV)HO-SO2-NH-SO2-OH

[0018] It is then reacted with a second base which is a + The salt formed to provide the above compound of formula (III). The compound of formula (III) thus obtained is further purified in water or other polar solvents such as alcohols.

[0019] EP 2415757 (in the name of CENTRAL GLASS CO., LTD.) discloses the reaction of a halogenated sulfonyl group (such as XSO2X, where X is Cl or F) or a halogenated phosphoryl group with ammonia in the presence of an organic base (B) to produce a B-XSI structure. Comparative Examples 1 and 2 disclose the reaction between SO2F2 and SO2Cl2 and NH3, respectively, without adding any base. Only sulfonamide compounds were isolated, and it was concluded that the target ammonium salt could hardly be obtained in the absence of an organic base.

[0020] US 8,840,856 B2 (in the name of Central Glass Co., Ltd.) claims a method for producing an imide salt, which comprises the following steps: reacting an alkali metal fluoride, a sulfuryl dihalide or a phosphoryl halide with ammonia or an ammonium salt. The presence of an alkali metal fluoride is mandatory, and in the examples, it is used in a molar excess relative to ammonia. According to Comparative Example 1, the reaction carried out in the absence of an alkali metal fluoride does not give the desired product, but rather gives a sulfonamide as the main component.

[0021] EP 2920147 B1 (to TRINAPCO Inc.) claims a process for producing a salt of a bis(fluorosulfonyl)imide anion, comprising adding sulfuryl fluoride to solid ammonium fluoride in a solvent in the presence of an aprotic base and isolating the resulting salt. In comparative example 1, NH4Cl is used in combination with a 1,3-bis(dimethylamino)propane (TMPDA) base. However, the product obtained thereby is not disclosed, only the formation of a mixture is described.

[0022] US2012 / 0245386 (granted to Trinapoquel) discloses a comparison of methods for adding NH3 to a SO2F2 solution in the presence of an organic base, preferably selected from N,N,N',N'-tetramethyl-1,2-ethylenediamine, N,N,N',N'-tetramethyl-1,3-propylenediamine and combinations thereof.

[0023] WO 2007 / 104144 (in the name of TRANSFERT PLUS, SEC) discloses a compound having the formula R1-SO2-R1 and R6-N - -R6 Q + wherein each R1 is independently F or Cl, each R6 is H, Li, Na, K, Cs or (R7)3Si- and Q + Selected from:

[0024]

[0025] The applicant is not aware of any disclosure of the preparation of NH4XSI (X is Cl or F) starting from ammonium salts without using a stoichiometric amount of a base. Summary of the invention

[0026] The Applicant has realised that, despite all the attempts made in the art, there is still a felt need to produce intermediate compounds suitable for the synthesis of lithium bis(fluorosulfonyl)imide (LiFSI) via a process that can be easily implemented on an industrial scale.

[0027] In particular, the Applicant faced the problem of producing intermediates suitable for the synthesis of LiFSI via a process that meets all the above requirements.

[0028] The Applicant has surprisingly found that bis(halosulfonyl)imines can be obtained by reacting a sulphuryl halide with at least one ammonium compound.

[0029] Such a process can advantageously be carried out in the absence of any base, which makes the process less complex and produces less solid waste than prior art processes.

[0030] The process according to the invention is also advantageous because the reactants and part of the by-products produced during the reaction can be recycled, thereby reducing the environmental factor (E factor) of the process, which is defined as the ratio between "total waste mass" and "product mass".

[0031] In addition to the above, the reaction according to the present invention can be easily controlled to limit both exothermic reactions and side reactions. DETAILED DESCRIPTION

[0032] In this application:

[0033] - any description (even those relating to a specific embodiment) is applicable to and interchangeable with other embodiments of the invention;

[0034] -When an element or component is said to be included in and / or selected from a list of listed elements or components, it should be understood that in the relevant embodiments explicitly considered herein, the element or component may also be any one of these listed independent elements or components, or may also be selected from a group consisting of any two or more of the explicitly listed elements or components; any element or component listed in the list of elements or components may be omitted from this list.

[0035] In a first aspect, the present invention relates to a process for producing a bis(halosulfonyl)imide having formula (I) or (II):

[0036]

[0037] in

[0038] Each X is independently selected from F, Cl and Br, and

[0039] R is a straight or branched chain alkyl group containing 1 to 10 carbon atoms;

[0040] The method comprises:

[0041] a) providing a product having the formula X a SO2X b Sulfuryl halides, wherein X is the same or different from each other a and X b Each of which is selected from F, Cl and Br;

[0042] b) providing at least one ammonium salt;

[0043] c) contacting the sulphuryl halide with the at least one ammonium salt to obtain a bis(halosulfonyl)imide having formula (I) or (II).

[0044] Preferably, in the case of a compound having the formula X a SO2X b In the sulfuryl halide, X a and X b Same as each other.

[0045] Preferably, the sulphuryl halide is selected from Cl-SO2-Cl, Cl-SO2-F and F-SO2-F; more preferably it is Cl-SO2-Cl.

[0046] Preferably, Cl-SO2-Cl is provided in its liquid form.

[0047] Preferably, each of Cl-SO2-F and F-SO2-F is provided in the form of its gas.

[0048] Preferably, the at least one ammonium salt complies with formula (III):

[0049] (III)

[0050]

[0051] in

[0052] R is a straight or branched chain alkyl group containing 1 to 10 carbon atoms, and

[0053] The M anion is selected from the group comprising, preferably consisting of, F, Cl, carboxylate, sulfate, bisulfate, carbonate, bicarbonate, tetrafluoroborate and hexafluorophosphate.

[0054] Preferably, the at least one ammonium salt is provided in its solid form.

[0055] Preferably, the ammonium salt is NH4Cl or NH4F.

[0056] In step c), the sulphuryl halide is reacted with the at least one ammonium salt to obtain the bis(halosulfonyl)imide of formula (I) or (II) as defined above.

[0057] Step c) can be carried out in the presence or in the absence of a solvent.

[0058] When step c) is carried out in the presence of a solvent, the solvent is preferably selected from the group comprising ethylene carbonate, propylene carbonate, butylene carbonate, γ-butyrolactone, γ-valerolactone, dimethoxymethane, 1,2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, 1,3-dioxane, 4-methyl-1,3-dioxolane, methyl formate, methyl acetate, methyl propionate, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, sulfolane, 3-methylsulfolane, dimethyl sulfoxide, N,N-dimethylformamide, N-methyloxazolidinone, acetonitrile, valeronitrile, benzonitrile, ethyl acetate, isopropyl acetate, n-butyl acetate, nitromethane and nitrobenzene.

[0059] When step c) is carried out in the absence of a solvent, the sulphuryl halide is advantageously in its liquid form. According to this embodiment, when Cl-SO2-F and F-SO2-F are used, they are liquefied under pressure before carrying out step c).

[0060] Preferably, step c) is performed at a temperature of about 15°C to about 150°C.

[0061] Preferably, step c) is carried out under stirring.

[0062] According to an embodiment, step c) is carried out in the presence of a solvent.

[0063] According to this embodiment, the temperature is appropriately selected based on the solvent used and its boiling temperature.For example, the temperature may be maintained between 15°C and 100°C, more preferably between 15°C and 75°C and even more preferably between 20°C and 50°C.

[0064] Furthermore, according to this embodiment, the molar ratio between the sulphuryl halide and the at least one ammonium salt in step c) is between 100 and 0.1, preferably between 10 and 1, more preferably between 1.5 and 1.

[0065] According to another embodiment, step c) is performed in the absence of any solvent (also called "neat conditions").

[0066] According to this embodiment, the temperature is between 50 and 100°C, more preferably between 60 and 70°C.

[0067] Furthermore, according to this embodiment, the molar ratio between the sulphuryl halide and the at least one ammonium salt is between 100 and 0.1, more preferably between 50 and 1, and even more preferably between 5 and 1.

[0068] When sulphuryl halide is used in excess as described in any of the above embodiments, the unreacted amount of sulphuryl halide may advantageously be distilled off. More preferably, such distilled amount of sulphuryl halide is recycled, ie provided under step a).

[0069] Preferably, in the process according to the invention, the sulphuryl halide is ClSO2Cl and the at least one ammonium salt is NH4 + Cl - .

[0070] According to such an embodiment, the method according to the invention comprises:

[0071] a*) providing a sulphuryl halide having the formula ClSO2Cl;

[0072] b) providing at least one compound having the formula NH4 + Cl - The ammonium salt of

[0073] c*) contacting the sulphuryl halide with the at least one ammonium salt to obtain a bis(halosulfonyl)imide having formula (I) wherein each X is chloro [ammonium-CSI].

[0074] The reaction in step c*) is advantageously carried out under the conditions disclosed above for step c).

[0075] The ammonium-CSI can be isolated or purified from the reaction environment. Alternatively, it can be used directly in a subsequent reaction.

[0076] Advantageously, ammonium-CSI may be reacted with a fluorine-containing compound to produce ammonium-FSI.

[0077] According to this embodiment, the process according to the invention comprises, after step c*), a step d) of contacting said ammonium-CSI with at least one fluorinating agent in order to obtain ammonium-FSI.

[0078] Therefore, step d) encompasses fluorination reaction of said ammonium-CSI to obtain ammonium-FSI.

[0079] Such a fluorinating agent is preferably selected from the group comprising HF, more preferably anhydrous HF, or X c F, where X c Selected from NH4, Cs, Li, K.

[0080] When the fluorinating agent is NH4F, the reaction proceeds producing NH4Cl as a by-product which can advantageously be recycled by providing it under step b).

[0081] Preferably, in the process according to the invention, the sulphuryl halide is ClSO2Cl and the at least one ammonium salt is NH4 + F - .

[0082] According to this embodiment, the method according to the invention comprises:

[0083] a**) providing a sulphuryl halide having the formula ClSO2Cl;

[0084] b) providing at least one compound having the formula NH4 + F - Ammonium salts of

[0085] c**) contacting the sulphuryl halide with the at least one ammonium salt to obtain a bis(halosulfonyl)imide having formula (I), wherein each X is fluoro[ammonium-FSI].

[0086] The reaction in step c**) is advantageously carried out under the conditions disclosed above for step c).

[0087] The ammonium-FSI obtained at the end of step d) or step c**) can be isolated or purified. Alternatively, such ammonium-FSI can be used directly in the subsequent reaction.

[0088] The ammonium-FSI obtained at the end of step d) or step c**) can advantageously be used as an intermediate compound for the manufacture of LiFSI.

[0089] According to a preferred embodiment, NH 4 -FSI is reacted with a lithiating agent to produce LiFSI.

[0090] Therefore, in a further embodiment, the present invention relates to a method for producing LiFSI, comprising reacting the ammonium-FSI with a LiX d step e) of contacting a compound of the formula (I) to obtain LiFSI.

[0091] Preferably, the compound LiX d selected from the group consisting of lithium chloride (LiCl), lithium fluoride (LiF), lithium carbonate (Li2CO3), lithium hydroxide (LiOH, LiOH.H2O), optionally in the form of its hydrate, lithium sulfate (Li2SO4), lithium carboxylate (Li n (RCO2) n ), Li2SiO3, Li2B4O7, and mixtures thereof.

[0092] Preferably, step e) is carried out in the presence of at least one solvent, so that LiFSI is obtained as a liquid composition.

[0093] Preferably, the at least one solvent is selected from the group comprising ethylene carbonate, propylene carbonate, butylene carbonate, γ-butyrolactone, γ-valerolactone, dimethoxymethane, 1,2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, 1,3-dioxane, 4-methyl-1,3-dioxolane, methyl formate, methyl acetate, methyl propionate, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, sulfolane, 3-methylsulfolane, dimethyl sulfoxide, N,N-dimethylformamide, N-methyloxazolidinone, acetonitrile, valeronitrile, benzonitrile, ethyl acetate, isopropyl acetate, n-butyl acetate, nitromethane and nitrobenzene.

[0094] More preferably, the solvent is selected from ethylene carbonate, propylene carbonate, butylene carbonate, tetrahydrofuran, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, ethyl acetate, isopropyl acetate and n-butyl acetate, and even more preferably the solvent includes dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, ethyl acetate, isopropyl acetate and n-butyl acetate. Even more preferably, the solvent is selected from ethyl methyl carbonate and n-butyl acetate.

[0095] More preferably, the liquid composition comprises 1 to 70 wt.%, even more preferably 5 to 50 wt.%, and still more preferably 15 to 40 wt.% of the LiFSI based on the total weight of the liquid composition.

[0096] The process of the present invention is carried out in a reactor.

[0097] Preferably, some steps or more preferably all steps of the method according to the invention are carried out in a reactor that can withstand the corrosion of reagents and the products and / or by-products obtained as the reaction proceeds. For this purpose, the part of the reactor that contacts the reaction medium is selected from corrosion-resistant materials.

[0098] Preferably, the corrosion resistant material is selected from alloys based on molybdenum, chromium, cobalt, iron, copper, manganese, titanium, zirconium, aluminum, carbon and tungsten, which are marketed under the trade name As especially C276 is commercially available; an alloy of nickel, chromium, iron, and manganese with additions of copper and / or molybdenum, sold under the trade name or Monel TM , such as especially 600, 625 or 718 are commercially available.

[0099] The corrosion resistant material may be selected from stainless steels, such as austenitic steels and more particularly 304, 304L, 316 or 316L stainless steels. Preferably, a steel having a nickel content of up to 22 wt.%, preferably between 6 wt.% and 20 wt.% and more preferably between 8 wt.% and 14 wt.% is used. 304 and 304L steels have a nickel content varying between 8 wt.% and 12 wt.%, and 316 and 316L steels have a nickel content varying between 10 wt.% and 14 wt.%. More preferably, 316L steel is selected.

[0100] The corrosion-resistant material may be a polymer compound resistant to corrosion by the reaction medium, which provides a coating on the part of the reactor in contact with the reaction medium. For example, PTFE (polytetrafluoroethylene or Teflon) or PFA (perfluoroalkyl resin) may be mentioned.

[0101] Alternatively and more preferably, the corrosion resistant material is selected from glass, glass lining and porcelain lining equipment.

[0102] Preferably and advantageously, all materials (including reactants) used in the method according to the invention may preferably show very high purity.

[0103] Preferably, their content of metal components such as Na, K, Ca, Mg, Fe, Cu, Cr, Ni, Zn is less than 10 ppm, more preferably less than 5 ppm, or less than 2 ppm.

[0104] In a further object, the present invention relates to the use of said liquid composition as a non-aqueous electrolyte solution in a battery.

[0105] Should the disclosure of any patents, patent applications, and publications incorporated herein by reference conflict with the description of the present application to the extent that it renders a term unclear, the present description shall take precedence.

[0106] The present invention will now be described in more detail with reference to the following examples, which are for illustrative purposes only and are not intended to limit the scope of the present disclosure.

[0107] Examples

[0108] Material

[0109] Sulfuryl chloride, acetonitrile, and ammonium chloride were purchased and used as received.

[0110] SO2Cl2: Sigma Aldrich (Product Code #157767, Batch #STBK3652)

[0111] NH4Cl: Alfa Alesar (Product Code #12361, Batch #Y28E029)

[0112] method

[0113] The signal enhancement method was insensitive nuclear polarization transfer (INEPT). 15 N-NMR analysis.

[0114] Example 1 (pure conditions)

[0115] In an oven-dried 25 mL round-bottom flask containing a PTFE-coated magnetic stirrer, ammonium chloride (1.6 g, 30 mmol, 0.3 eq) was added portionwise to neat sulfuryl chloride (8.08 mL, 100 mmol, 1 eq) at 0°C under stirring. The flask was equipped with a reflux condenser, and the reaction mixture was stirred at reflux for 24 hours. The reaction mixture was then cooled to room temperature, filtered and concentrated under reduced pressure to give an orange solid.

[0116] Trituration in acetonitrile finally afforded the pure product as a white solid.

[0117] The yield was 44% (1.54 g, 6.6 mmol) and 1 H-NMR and 15 N-NMR analysis revealed characteristic peaks.

[0118] Example 2 (using acetonitrile as solvent)

[0119] Following the procedure disclosed in Example 1 above, excess sulfuryl chloride was reacted with ammonium chloride, but the reaction was carried out in the presence of acetonitrile as solvent.

[0120] The reaction medium is filtered to remove the ammonium chloride and a mixture is obtained, which is then 1The mixture was analyzed by H-NMR.

[0121] pass 1 H-NMR and 15 This compound was further analyzed by N-NMR. No peaks of HCSI or other by-products were detected.

[0122] Example 3 (pure conditions)

[0123] Following the same procedure disclosed in Example 1 above, SO2Cl2 maintained at its boiling point was reacted with a substoichiometric amount of NH4Cl.

[0124] After 1 hour of reaction at 69° C., the reaction medium begins to solidify and at the end of 24 hours of reaction, a mixture of ammonium-CSI and unreacted solid NH 4 Cl is recovered.

[0125] Ammonium-CSI was obtained in 48% yield. 1 H-NMR and 15 N-NMR analysis and characterization of the product.

Claims

1. A method for producing a bis(halosulfonyl)imide having formula (I) or (II): (AND) (II) in R is a straight or branched chain alkyl group containing 1 to 10 carbon atoms, and Each X is independently selected from F, Cl and Br; The method comprises: a) providing a product having the formula X a SO2X b Sulfuryl halides X that are the same or different from each other a and X b Each of which is selected from F, Cl and Br; b) providing at least one ammonium salt; c) contacting the sulphuryl halide with the at least one ammonium salt to obtain the bis(halosulfonyl)imide of formula (I) or (II).

2. The method according to claim 1, wherein: The sulfuryl halide is selected from the group consisting of Cl-SO2-Cl, Cl-SO2-F and F-SO2-F.

3. The method according to claim 1 or 2, wherein: The at least one ammonium salt conforms to formula (III): in R is H or a straight or branched chain alkyl group containing 1 to 10 carbon atoms, and M is selected from the group comprising: F, Cl, carboxylate, sulfate, bisulfate, carbonate, bicarbonate, tetrafluoroborate, hexafluorophosphate.

4. A method according to any one of the preceding claims, wherein: Step c) is carried out at a temperature of 15° C. to 150° C. and / or under stirring.

5. A method according to any one of the preceding claims, wherein: Step c) is carried out in the presence of a solvent.

6. The method according to claim 5, wherein: The solvent is selected from the group consisting of ethylene carbonate, propylene carbonate, butylene carbonate, γ-butyrolactone, γ-valerolactone, dimethoxymethane, 1,2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, 1,3-dioxane, 4-methyl-1,3-dioxolane, methyl formate, methyl acetate, methyl propionate, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, sulfolane, 3-methylsulfolane, dimethyl sulfoxide, N,N-dimethylformamide, N-methyloxazolidinone, acetonitrile, valeronitrile, benzonitrile, ethyl acetate, isopropyl acetate, n-butyl acetate, nitromethane and nitrobenzene.

7. The method according to claim 5 or 6, wherein: Step c) is carried out with a molar ratio between the sulphuryl halide and the at least one ammonium salt of between 100 and 0.1, preferably between 10 and 1, more preferably between 1.5 and 1.

8. The method according to any one of claims 1 to 4, wherein: Step c) is carried out in the absence of a solvent and / or at a temperature between 50 and 100 °C, more preferably between 60 and 70 °C.

9. A method according to any one of the preceding claims, wherein: The molar ratio between the sulphuryl halide and the at least one ammonium salt is between 100 and 0.1, preferably between 50 and 1 and more preferably between 5 and 1.

10. A method according to any one of the preceding claims, wherein: In the bis(halosulfonyl)imide of formula (I), each X is chloro[ammonium-CSI], and the method comprises: a*) providing a sulphuryl halide having the formula ClSO2Cl; b) providing at least one compound having the formula NH4 + Cl - Ammonium salts of c*) contacting said sulphuryl halide with said at least one ammonium salt, thereby obtaining said ammonium-CSI.

11. The process according to claim 10, comprising, after step c*), a step d) of contacting the ammonium-CSI with at least one fluorinating agent in order to obtain ammonium-FSI.

12. The method according to claim 11, wherein: The at least one fluorinating agent is selected from the group consisting of HF, more preferably anhydrous HF, or X c F, where X c Selected from NH4, Cs, Li, K.

13. The method according to any one of claims 1 to 9, wherein: In the bis(halosulfonyl)imide of formula (I), each X is fluoro[ammonium-FSI], and the method comprises: a**) providing a sulphuryl halide having the formula ClSO2Cl; b) providing at least one compound having the formula NH4 + F - Ammonium salts of c**) contacting said sulphuryl halide with said at least one ammonium salt, thereby obtaining said ammonium-FSI.

14. A method for producing lithium bis(fluorosulfonyl)imide (LiFSI), said method comprising reacting the ammonium-FSI with a bis(fluorosulfonyl)imide having the formula LiX d step e) of contacting a compound of the formula (I) to obtain LiFSI.

15. The method according to claim 14, wherein: The LiX d The compound is selected from the group consisting of LiCl, LiF, Li2CO3, LiOH, LiOH.H2O, Li2SO4, Li n (RCO2) n , Li2SiO3, Li2B4O7 and mixtures thereof.

16. The method according to claim 14 or 15, wherein: Step e) is performed in the presence of at least one solvent and obtains LiFSi as a liquid composition comprising 1 to 70 wt. % of LiFSI based on the total weight of the liquid composition.

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