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.

An electrolyte composition includes: a sulfonylimide compound represented by the following general formula (1) as an electrolyte salt; and an amidosulfuric acid component.

LiN(X.sup.1SO.sub.2)(X.sup.2SO.sub.2)  (1) (where X.sup.1 and X.sup.2 are identical to or different from each other, and each represent a fluorine atom, an alkyl group with a carbon number of 1 to 6, or a fluoroalkyl group with a carbon number of 1 to 6).

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 method of producing purified bis(fluorosulfonyl) imide includes providing a liquid mixture including bis(fluorosulfonyl) imide and fluorosulfonic acid and then contacting the liquid mixture with gaseous ammonia. The gaseous ammonia reacts with the fluorosulfonic acid to produce ammonium fluorosulfate. The method further includes separating the liquid mixture from the ammonium fluorosulfate.

A method of producing purified bis(fluorosulfonyl) imide includes providing a liquid mixture including bis(fluorosulfonyl) imide and fluorosulfonic acid and then contacting the liquid mixture with gaseous ammonia. The gaseous ammonia reacts with the fluorosulfonic acid to produce ammonium fluorosulfate. The method further includes separating the liquid mixture from the ammonium fluorosulfate.

A method for drying and purifying a lithium bis(fluorosulfonyl)imide salt. Also, a method for producing a lithium bis(fluorosulfonyl)imide salt which is then dried and purified by the method. Further, a composition containing lithium bis(fluorosulfonyl)imide salt having a water content by mass of between 5 and 45 ppm. And, the use of the composition C in Li-ion batteries.

A method for producing a bis(fluorosulfonyl)imide lithium salt is disclosed. The method includes the steps of: (a) reacting bis(chlorosulfonyl)imide with NH.sub.4F(HF)n (n=0-10) to prepare ammonium bis(fluorosulfonyl)imide; and (b) reacting the ammonium bis(fluorosulfonyl)imide with a lithium base, wherein in at least one of steps (a) and (b), after the reaction, a process of adding an alkoxy trialkyl silane to the reaction solution to remove a fluorine anion is performed.

A method for drying and purifying a lithium bis(fluorosulfonyl)imide salt. Also, a method for producing a lithium bis(fluorosulfonyl)imide salt which is then dried and purified by the method. Further, a composition containing lithium bis(fluorosulfonyl)imide salt having a water content by mass of between 5 and 45 ppm.

And, the use of the composition C in Li-ion batteries.

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 of producing purified bis(fluorosulfonyl) imide includes providing a liquid mixture including bis(fluorosulfonyl) imide and fluorosulfonic acid and then contacting the liquid mixture with gaseous ammonia. The gaseous ammonia reacts with the fluorosulfonic acid to produce ammonium fluorosulfate. The method further includes separating the liquid mixture from the ammonium fluorosulfate.