The invention relates to a method for producing a fluorine- and sulphur-bearing compound of formula F—SO—R (I) or F—SO.sub.2—R (II), comprising the reaction, in the presence of water, of at least one salt providing a fluoride anion and at least one halgoenosulfoxide compound of formula X—SO—R′ (I0) from a halogenosulfonyl compound of formula X—SO.sub.2—R′ (II0), in which X is a halogen atom other than fluorine and R and R′ are each a group linked by a covalent bond to the sulphur atom, said bond linking the sulphur atom with a nitrogen atom. The invention also relates to a method for producing salts of a fluorine- and sulphur-bearing compound of formula F—SO—R (I) or F—SO.sub.2—R (II) which are advantageously used as electrolyte salts, as precursors of antistatic agents or as surfactant precursors.

A fluorination process for obtaining fluorinated compounds including at least one fluorosulfonyl group. More particularly, a process for preparing a fluorinated compound of formula (II), including at least one step of reacting a compound of formula (I) with anhydrous hydrofluoric acid in at least one organic solvent, in which R1 is equal to R2 except in the specific case where R1═Cl, then R2═F, and when R1 is equal to R2, R1 and R2 represent an electron-withdrawing group which has a Hammett parameter σp of greater than 0, such as F, CF.sub.3, CHF.sub.2, CH.sub.2F, C.sub.2HF.sub.4, C.sub.2H.sub.2F.sub.3, C.sub.2H.sub.3F.sub.2, C.sub.2F.sub.5, C.sub.3F.sub.7, C.sub.3H.sub.2F.sub.5, C.sub.3H.sub.4F.sub.3, C.sub.3HF.sub.6, C.sub.4F.sub.9, C.sub.4H.sub.2F.sub.7, C.sub.4H.sub.4F.sub.5, C.sub.5F.sub.11, C.sub.3F.sub.5OCF.sub.3, C.sub.2F.sub.4OCF.sub.3, C.sub.2H.sub.2F.sub.2OCF.sub.3, CF.sub.2OCF.sub.3, C.sub.6F.sub.13, C.sub.7F.sub.15, C.sub.8F.sub.17 or C.sub.9F.sub.19, and M represents a hydrogen atom, an alkali metal, an alkaline-earth metal or a quaternary ammonium cation.

The invention relates to a process for preparing bis(fluorosulfonyl) imide, comprising the steps of: i) providing a stream A1 containing HF and a reactor containing a liquid phase A2 that contains bis(chlorosulfonyl) imide; ii) in said reactor, bringing said liquid phase A2 into contact with said stream A1 to produce bis(fluorosulfonyl) imide, said process being characterized in that said stream A1 is injected into said liquid phase A2.

The invention relates to a process for preparing bis(fluorosulfonyl) imide, comprising the steps of: i) providing a stream A1 containing hydrofluoric acid; providing a reactor containing a liquid phase A2 that contains bis(halosulfonyl) imide; providing at least one mixing device that is connected to the inlet of said reactor; ii) supplying liquid phase A2 and stream A1 to the at least one mixing device; iii) bringing liquid phase A2 into contact with stream A1 in the mixing device to form a reaction mixture B in liquid form containing bis(fluorosulfonyl) imide; iv) introducing the reaction mixture B produced in step iii) into the liquid phase A2 in the reactor.

A composition containing: at least 99.75% by weight of bis(fluorosulfonyl)imide lithium salt. A process for preparing the composition, including a) step of preconcentrating a composition C1 including an organic solvent OS1, water and bis(fluorosulfonyl)imide salt, to give a composition C2 including: the lithium salt of bis(fluorosulfonyl)imide in a content ranging from 35% to 50% relative to the total weight of composition C2; water in a mass content of less than or equal to 500 ppm relative to the total mass of composition C2; the preconcentration step being performed at a temperature of less than or equal to 50° C.; b) a step of concentrating composition C2; c) an optional step of crystallizing the composition obtained in step b).

The present invention relates to a process for preparing a compound having the following formula (II):

F—SO.sub.2—N.sup.−—SO.sub.2—R.sub.1NH.sub.4.sup.+  (II)

wherein R.sub.1 represents F or a linear or branched alkyl radical, substituted with at least one fluorine atom, said process comprising a step of bringing an anhydrous flow F1 comprising ammonia (NH.sub.3) into contact with a compound of formula (I):

F—SO.sub.2—NH—SO.sub.2—R.sub.1  (I)

R.sub.1 is as defined above.

The invention relates to a method for producing an alkali salt of bis(fluorosulfonyl)imide, comprising the step of reacting, within a reaction medium, an ammonium salt of bis(fluorosulfonyl)imide with an alkali agent, to produce alkali salt of bis(fluorosulfonyl)imide and ammonia; and simultaneously contacting the reaction medium with an inert gas stream to strip out ammonia.

A method for drying and purifying a lithium bis(fluorosulfonyl)imide salt in solution in an organic solvent S1, the method including the following steps: a) adding deionised water to dissolve and extract the lithium bis(fluorosulfonyl)imide salt, forming an aqueous solution of the salt; b) extracting the lithium bis(fluorosulfonyl)imide salt from the aqueous solution, using an organic solvent S2, the step being repeated at least once; c) concentrating the lithium bis(fluorosulfonyl)imide salt by evaporating the organic solvent S2 and the water, in a short-path thin-film evaporator, under the following conditions: temperature of 30° C. to 95° C., pressure of 10.sup.−3 mbar abs to 5 mbar abs, residence time no longer than 15 min; and d) optionally crystallising the lithium bis(fluorosulfonyl)imide salt. Also, a composition made of lithium bis(fluorosulfonyl)imide salt, and the uses thereof in Li-ion batteries.

The present invention relates to a method for drying and purifying a lithium bis(fluorosulfonyl)imide salt in solution in an organic solvent S1, said method comprising the following steps: a) adding deionised water to dissolve and extract the lithium bis(fluorosulfonyl)imide salt, forming an aqueous solution of said salt; b) extracting the lithium bis(fluorosulfonyl)imide salt from said aqueous solution, using an organic solvent S2, said step being repeated at least once; c) concentrating the lithium bis(fluorosulfonyl)imide salt by evaporating said organic solvent S2 and the water, in a short-path thin-film evaporator, under the following conditions: temperature of 30° C. to 95° C., pressure of 10.sup.−3 mbar abs to 5 mbar abs, residence time no longer than 15 min; and d) optionally crystallising the lithium bis(fluorosulfonyl)imide salt. The present invention likewise relates to a composition made of lithium bis(fluorosulfonyl)imide salt, and the uses thereof in Li-ion batteries.

A composition containing: at least 99.75% by weight of bis(fluorosulfonyl)imide lithium salt; and acetic acid in a content by mass greater than 0 and less than or equal to 400 ppm. A process for preparing the composition, including a) step of preconcentrating a composition C1 including an organic solvent OS1, water and bis(fluorosulfonyl)imide salt, to give a composition C2 including: the lithium salt of bis(fluorosulfonyl)imide in a content ranging from 35% to 50% relative to the total weight of composition C2; water in a mass content of less than or equal to 500 ppm relative to the total mass of composition C2; said preconcentration step being performed at a temperature of less than or equal to 50° C.; b) a step of concentrating composition C2; c) an optional step of crystallizing the composition obtained in step b).