Electrolyte purification method using calcium carbide, and electrolytes thus obtained

Patent metadata

Field	Value
Publication number	US-10147978-B2
Application number	US-99127006-A
Country	US
Kind code	B2
Filing date	Jul 28, 2006
Priority date	Aug 29, 2005
Publication date	Dec 4, 2018
Grant date	Dec 4, 2018

Abstract

Process for the purification of an ionic electrolyte comprising at least one alkali metal salt, the process having at least one stage in which particles of at least one calcium salt are brought into contact. The process makes it possible to obtain electrolytes characterized in particular by a particularly low water content. The corresponding electrochemical generators which incorporate the electrolyte as constituent component are characterized by a noteworthy stability and are particularly safe.

First claim

What is claimed is:

1. A method for the purification of a liquid ionic electrolyte, said method comprising at least one step in which particles of at least one calcium salt are brought into contact with the electrolyte, wherein:
the electrolyte comprises at least one alkali metal salt dissolved in a liquid solvent, the alkali metal salt is LiFSI, LiTFSI, LiBETl, LiPF 6 , LiClO 4 , LIBF 4 , LiCF 3 SO 3 , LIBOB, LiDCTA or a mixture thereof, and
said calcium salt is CaC 2 .

2. The method of claim 1 , wherein the particles of the CaC 2 have a d 50 of between 1 and 100 micrometers, limits included.

3. The method of claim 1 , wherein the particles of the CaC 2 have sizes between 100 micrometers and 1 nanometer.

4. The method of claim 1 , wherein the particles of CaC 2 have a specific surface, measured according to the BET method, which is between 5 and 200 m 2 /g, limits included.

5. The method of claim 1 , wherein the amount of CaC 2 used is in excess with respect to the amount of water to be removed, the amount of calcium salt used representing at least 5 g per 20 ml of electrolyte to be purified.

6. The method of claim 1 , wherein particles of the CaC 2 are brought into contact with the electrolyte by adding particles of calcium salt to the electrolyte and by homogenizating the mixture thus obtained.

7. The method of claim 1 , wherein particles of the CaC 2 are brought into contact with the electrolyte by continuous percolation of the liquid electrolyte over a bed of calcium salt until the bed of calcium salt has been exhausted.

8. The method of claim 1 , wherein the liquid solvent is selected from ethylene carbonate (EC), propylene carbonate (PC), dimethylethylene (DME), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), γ-butyrolactone (GBL) and mixtures thereof.

9. The method of claim 1 , wherein the liquid solvent is a solvent having a low boiling point, selected from acetone, toluene, heptane and ethanol.

Assignees

• Zaghib Karim
• Jalbert Jocelyn
• Guerfi Abdelbast
• Michot Christophe
• Gauthier Michel
• Dontigny Martin
• Charest Patrick
• Hydro Quebec

Inventors

• Zaghib Karim
• Jalbert Jocelyn
• Guerfi Abdelbast
• Michot Christophe
• Gauthier Michel
• Dontigny Martin
• Charest Patrick

Classifications

• H01M10/4242 Primary

  Regeneration of electrolyte or reactants · CPC title

• H01M10/0566

  Liquid materials · CPC title

• H01M2300/0085

  Immobilising or gelification of electrolyte · CPC title

• B01D15/00

  Separating processes involving the treatment of liquids with solid sorbents; Apparatus therefor · CPC title

• H01M10/0565

  Polymeric materials, e.g. gel-type or solid-type · CPC title