Process for recovering an electrolyte salt

Patent metadata

Field	Value
Publication number	US-2017110769-A1
Application number	US-201515318119-A
Country	US
Kind code	A1
Filing date	Jun 16, 2015
Priority date	Jun 18, 2014
Publication date	Apr 20, 2017
Grant date	—

Abstract

The present invention relates to a process for recovering a metal salt of an electrolyte dissolved in a matrix, said process consisting in subjecting the electrolyte to a liquid extraction with water.

First claim

1 . A process for recovering a metal salt of an electrolyte dissolved in a matrix, said process consisting in subjecting the electrolyte to a liquid extraction with water, wherein the metal salt is selected from the group consisting of sulfonimides, perchlorates, sulfonates, difluorophosphates and mixtures thereof.

2 . The process as claimed in claim 1 , wherein the metal salt is an organic or inorganic salt of an alkali metal.

3 . The process as claimed in claim 2 , wherein the metal salt is a salt of an alkali metal selected from the group consisting of K, Li, Na and Cs.

4 . The process as claimed in claim 3 , wherein the metal salt is a lithium salt.

5 . The process as claimed in claim 1 , wherein the metal salt is a sulfonimide having the formula (Rf 1 SO 2 )(Rf 2 SO 2 )NM b , M b representing an alkali metal, Rf 1 and Rf 2 independently representing a fluorine atom or a group having from 1 to 10 carbon atoms.

6 . The process as claimed in claim 5 , wherein the metal salt is lithium bis(trifluoromethanesulfonyl)imide, lithium bis(fluorosulfonyl)imide or lithium bis(perfluoroethanesulfonyl)imide.

7 . The process as claimed in claim 6 , wherein the metal salt is lithium bis(trifluoromethanesulfonyl)imide.

8 . The process as claimed in claim 1 , wherein the metal salt is selected from the group consisting of LiClO 4 and LiOTf.

9 . The process as claimed in claim 1 , wherein the matrix comprises a polymer or a gel.

10 . The process as claimed in claim 1 , wherein the matrix of the electrolyte comprises an organic solvent, this electrolyte being miscible with water, and this electrolyte being successively or simultaneously subjected to a liquid extraction with water and with an organic extraction solvent which is water-immiscible.

11 . The process as claimed in claim 10 , wherein the organic extraction solvent which is water-immiscible is a chlorinated solvent.

12 . The process as claimed in claim 10 , wherein, at the end of the two liquid extractions, two liquid phases are present: an aqueous phase in which substantially all the metal salt is dissolved and an organic phase containing substantially all the organic solvent of the electrolyte and the organic extraction solvent, and these two phases are separated.

13 . The process as claimed in claim 12 , wherein the organic phase containing the solvent(s) of the electrolyte and the extraction solvent is treated so as to separate the solvents.

14 . The process as claimed in claim 1 , wherein an aqueous extraction solution containing the metal salt obtained by subjecting the electrolyte to the liquid extraction with water is dried, so as to extract therefrom the metal salt.

15 . The process as claimed in claim 1 , wherein the metal salt is LiTFSI and the aqueous extraction solution containing the LiTFSI is acidified so as to generate HTFSI and LiOH which are isolated and then brought into contact with one another again so as to regenerate the LiTFSI.

16 . The process as claimed in claim 5 , wherein M b is selected from the group consisting of K, Li, Na and Cs.

17 . The process as claimed in claim 5 , wherein the group having from 1 to 10 carbon atoms is selected from the group consisting of fluoroalkyls, perfluoroalkyls and fluoroalkenyls.

18 . The process as claimed in claim 11 , wherein the chlorinated solvent is chloroform, dichloroethane, perchloroethylene, methylene chloride and/or chlorobenzene.

19 . The process as claimed in claim 12 , wherein the two phases are separated by settling out or by centrifugation.

20 . The process as claimed in claim 13 , wherein the organic phase containing the solvent(s) of the electrolyte and the extraction solvent is treated so as to separate the solvents by distillation.

Assignees

• Rhodia Operations

Inventors

• Metz François

Classifications

• H01M10/54 Primary

  Reclaiming serviceable parts of waste accumulators · CPC title

• B01D11/04 Primary

  of solutions which are liquid · CPC title

• H01M10/0568

  characterised by the solutes · CPC title

• B01D11/02 Primary

  of solids · CPC title

• H01M6/52

  Reclaiming serviceable parts of waste cells or batteries {, e.g. recycling} · CPC title