Electrolyte purification method using calcium carbide, and electrolytes thus obtained

Patent metadata

Field	Value
Publication number	US-10811731-B2
Application number	US-201816186777-A
Country	US
Kind code	B2
Filing date	Nov 12, 2018
Priority date	Aug 29, 2005
Publication date	Oct 20, 2020
Grant date	Oct 20, 2020

Abstract

Process for the purification of an ionic electrolyte including 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 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

The invention 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 molten salt which is liquid at a temperature between −30° C. and 350° C.,
said calcium salt is CaC 2 .

2. The method of claim 1 , wherein the particles of the CaC 2 have a d50 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 homogeneization of 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. 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 is a liquid composition containing a polymer which is able to provide a gel by cross-linking, and contacting the electrolyte with the calcium salts is carried out prior to cross-linking,
said calcium salt is CaC 2 .

9. The method of claim 8 , wherein the particles of the CaC 2 have a d50 of between 1 and 100 micrometers, limits included.

10. The method of claim 8 , wherein the particles of the CaC 2 have sizes between 100 micrometers and 1 nanometer.

11. The method of claim 8 , 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.

12. The method of claim 8 , 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.

13. The method of claim 8 , wherein particles of the CaC 2 are brought into contact with the electrolyte by adding particles of calcium salt to the electrolyte and by homogeneization of the mixture thus obtained.

14. The method of claim 8 , 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.

Assignees

• Hydro Quebec

Inventors

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

Classifications

• H01M2300/0085

  Immobilising or gelification of electrolyte · CPC title

• H01M10/0566

  Liquid materials · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M10/0565

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

• B01D15/00

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