Method for purifying difluorophosphate

Patent metadata

Field	Value
Publication number	US-10717650-B2
Application number	US-201615562223-A
Country	US
Kind code	B2
Filing date	Apr 26, 2016
Priority date	Apr 27, 2015
Publication date	Jul 21, 2020
Grant date	Jul 21, 2020

Abstract

Disclosed is a method for purifying a difluorophosphate, the method including mixing a difluorophosphate containing an impurity with at least one treatment agent selected from the group consisting of carbonates, hydroxides, and halides of alkali metals or alkali earth metals and amines to isolate the impurity. It is preferable that the method further include filtering off, by filtration, a salt or a complex that has been formed by allowing the impurity to be mixed with the treatment agent. Preferably, a carbonate, a hydroxide, or a halide of an alkali metal is used as the treatment agent, and more preferably a carbonate, a hydroxide, or a halide of lithium is used as the treatment agent.

First claim

The invention claimed is:

1. A method for purifying a difluorophosphate, the method comprising:
dissolving difluorophosphate containing an impurity in a solvent to form a solution;
mixing at least one treatment agent with the solution to isolate the impurity contained in the difluorophosphate;
wherein at least one treatment agent is selected from the group consisting of alkali metal carbonates, alkali metal hydroxides, alkali metal halides, alkaline earth metal carbonates, alkaline earth metal hydroxides, and alkaline earth metal halides.

2. The method for purifying a difluorophosphate according to claim 1 , further comprising filtering off, by filtration, a salt or a complex that has been formed by allowing the impurity to be mixed with the treatment agent.

3. The method for purifying a difluorophosphate according to claim 1 , wherein the treatment agent is a carbonate, a hydroxide, or a halide of an alkali metal.

4. The method for purifying a difluorophosphate according to claim 1 , wherein the treatment agent is a carbonate, a hydroxide, or a halide of lithium.

5. The method for purifying a difluorophosphate according to claim 1 , wherein a reaction between the impurity and the treatment agent is conducted in a solvent.

6. The method for purifying a difluorophosphate according to claim 5 , wherein the solvent is an acetate ester, an ester of a phosphorus acid, a nitrile compound, an amide compound, an alcohol, or an alkane.

7. The method for purifying a difluorophosphate according to claim 2 , wherein the treatment agent is a carbonate, a hydroxide, or a halide of an alkali metal.

8. The method for purifying a difluorophosphate according to claim 2 , wherein the treatment agent is a carbonate, a hydroxide, or a halide of lithium.

9. The method for purifying a difluorophosphate according to claim 3 , wherein the treatment agent is a carbonate, a hydroxide, or a halide of lithium.

10. The method for purifying a difluorophosphate according to claim 2 , wherein a reaction between the impurity and the treatment agent is conducted in a solvent.

11. The method for purifying a difluorophosphate according to claim 3 , wherein a reaction between the impurity and the treatment agent is conducted in a solvent.

12. The method for purifying a difluorophosphate according to claim 4 , wherein a reaction between the impurity and the treatment agent is conducted in a solvent.

13. The method for purifying a difluorophosphate according to claim 7 , wherein a reaction between the impurity and the treatment agent is conducted in a solvent.

14. The method for purifying a difluorophosphate according to claim 8 , wherein a reaction between the impurity and the treatment agent is conducted in a solvent.

15. The method for purifying a difluorophosphate according to claim 9 , wherein a reaction between the impurity and the treatment agent is conducted in a solvent.

16. A method for purifying a difluorophosphate, the method comprising:
mixing a difluorophosphate containing an impurity with at least one treatment agent selected from the group consisting of amines to isolate the impurity contained in the difluorophosphate.

17. The method for purifying a difluorophosphate according to claim 16 , further comprising filtering off, by filtration, a salt or a complex that has been formed by allowing the impurity to be mixed with the treatment agent.

18. The method for purifying a difluorophosphate according to claim 16 , wherein a reaction between the impurity and the treatment agent is conducted in a solvent.

19. The method for purifying a difluorophosphate according to claim 17 , wherein a reaction between the impurity and the treatment agent is conducted in a solvent.

20. The method for purifying a difluorophosphate according to claim 1 , wherein a dried difluorophosphate containing an impurity is dissolved in a solvent.

Assignees

• Kanto Denka Kogyo Kk

Inventors

• Takizawa Hiroki
• Yoshiyama Kazuhide
• Kude Keisuke
• Kashikura Wataru
• Abe Takuro
• Shimoda Mitsuhara
• Omae Osamu
• Uehara Hiroyuki

Classifications

• Y02E60/10

  Energy storage using batteries · CPC title

• Y02T10/70

  Energy storage systems for electromobility, e.g. batteries · CPC title

• H01M10/0568

  characterised by the solutes · CPC title

• C01B25/455 Primary

  containing halogen {(completely halogenated alkali metal phosphates C01D, e.g. lithium hexafluorophosphate C01D15/005)} · CPC title

• C01P2006/40

  Electric properties · CPC title