Method for fluorinating hydrogen bis(chlorosulfonyl)imide in gas phase

Patent metadata

Field	Value
Publication number	US-2026001761-A1
Application number	US-202318880525-A
Country	US
Kind code	A1
Filing date	Jun 23, 2023
Priority date	Jul 1, 2022
Publication date	Jan 1, 2026
Grant date	—

Abstract

The present invention relates to a method for producing bis(fluorosulfonyl)imide acid, which is economically feasible at industrial scale and which provides a high-purity product.

First claim

1 . A method for producing bis(fluorosulfonyl)imide acid (HFSI), said method comprising the step of contacting gaseous bis(chlorosulfonyl)imide acid (HCSI) with gaseous anhydrous hydrogen fluoride (HF), wherein said method is carried out in the absence of solvent.

2 . The method according to claim 1 , wherein gaseous HCSI is obtained from solid or molten HCSI by heating the same to a temperature above HCSI boiling point (TbHCSI) and/or by HCSI reduced pressure vaporization.

3 . The method according to claim 1 , wherein gaseous HCSI is obtained from HCSI in liquid state by a two steps procedure comprising:
a) melting solid HCSI to a temperature above its melting temperature (Tm HCSI ); and b) further heating to a temperature above its boiling point (Tb HCSI ).

4 . The method according to claim 1 , wherein gaseous HCSI is loaded into a closed reactor for contacting with gaseous anhydrous HF in admixture with a carrier gas [mixture (M1)].

5 . The method according to claim 1 , wherein gaseous anhydrous HF is loaded into the closed reactor for contacting with gaseous HCSI in admixture with a carrier gas [mixture (M2)].

6 . The method according to claim 4 , wherein the carrier gas is nitrogen.

7 . The method according to claim 1 , wherein the molar ratio between HCSI and the anhydrous HF is between 1:1 and 1:3.

8 . The method according to claim 1 , wherein contacting the HCSI and gaseous anhydrous HF is carried out in a closed reactor in the presence of carrier gas deriving from a mixture (M1) and/or from a mixture (M2) and wherein the ratio between HCSI and a total amount of carrier gas in the reactor mixture is between 1:3 and 1:30.

9 . The method according to claim 1 , wherein the step of contacting gaseous HCSI with gaseous anhydrous HF is carried out in a closed reactor at a temperature of from 100 to 300° C.

10 . The method according to claim 1 , wherein the residence time of the HCSI and the anhydrous HF in the closed reactor is between 10 seconds to 3 hours.

11 . A method of making an alkali metal salt, an alkaline-earth metal salt or a quaternary ammonium cation salt of HFSI, said method comprising:
(a) producing bis(fluorosulfonyl)imide acid (HFSI) via a method comprising the step of contacting gaseous bis(chlorosulfonyl)imide acid (HCSI) with gaseous anhydrous hydrogen fluoride (HF), wherein said method is carried out in the absence of solvent, and (b) salifying the so obtained HFSI.

12 . The method according to claim 11 , wherein the step of salification of HFSI is carried out with a lithium salt so as to provide lithium bis(fluorosulfonyl)imide (LiFSI).

13 . A bis(fluorosulfonyl)imide acid (HFSI) obtained by the method according to claim 1 .

14 . A lithium bis(fluorosulfonyl)imide (LiFSI) obtained by the method according to claim 11 .

15 . A method comprising incorporating the lithium bis(fluorosulfonyl)imide (LiFSI) according to claim 14 in a non-aqueous electrolyte for batteries.

16 . An electrolyte composition comprising the lithium bis(fluorosulfonyl)imide (LiFSI) according to claim 15 .

Assignees

• Specialty Operations France
• Centre Nat Rech Scient
• Univ Poitiers

Inventors

• Perin Eric
• Brunet Sylvette
• Dieu Julien

Classifications

• H01M2300/0025

  Organic electrolyte · CPC title

• H01M10/0568 Primary

  characterised by the solutes · CPC title

• C01P2006/40

  Electric properties · CPC title

• C01B21/093

  containing also one or more sulfur atoms · CPC title

• C01B21/086 Primary

  containing one or more sulfur atoms · CPC title