Magnesium salts

Patent metadata

Field	Value
Publication number	US-9985290-B2
Application number	US-201615043888-A
Country	US
Kind code	B2
Filing date	Feb 15, 2016
Priority date	Feb 15, 2016
Publication date	May 29, 2018
Grant date	May 29, 2018

Abstract

Described is a salt of the general formula: Mg 2+ (L x ) 6 (PF 6 ) 2 wherein each L is a ligand selected from dichloromethane, a cyclic ether, or a nitrile of the general formula R—C≡N. The method of making the salt comprises the steps: providing Mg metal, activating the Mg metal in a first dry solution comprising a first ligand solution (L 1 ), treating the dry solution of activated Mg metal and L 1 with NOPF 6 in a second dry solution comprising a second ligand solution (L 2 ), heating the treated Mg metal solution removing residual solvent under vacuum, and recrystallizing the remaining solid to form the salt wherein L x comprises a mixture of L 1 and L 2 . The salt can be used as the salt in an electrolyte, or as an additive to an electrolyte, in a cell or battery.

First claim

The invention claimed is:

1. A salt of the general formula:
Mg 2+ (L) x (PF 6 ) 2   (i)

wherein x represents a number between 1 and 6; and
each L represents a ligand selected from one of the following compounds:
a halomethane,
a cyclic crown ether; or
a nitrile of the general formula R—C≡N.

2. The salt of claim 1 , wherein x is greater than 1, and L represents a ligand selected from only one of the following compounds:
a halomethane,
a cyclic crown ether; or
a nitrile of the general formula R—C≡N.

3. The salt of claim 2 , wherein each ligand L is acetonitrile.

4. The salt of claim 1 , wherein x is equal to 6, ligand L is a nitrile and R represents an organic group independently selected from the following: methyl, ethyl, propyl, butyl, t butyl, pentyl, ethylene, propylene, butylene, pentylene, toluene, naphthalene, or phenyl.

5. The salt of claim 4 , wherein R is the same for each ligand represented by L.

6. The salt of claim 1 , wherein x is equal to 1 and L is a cyclic crown ether selected from one of the following: [12]-crown-4, [18]-crown-6, [24]-crown-8.

7. The salt of claim 1 , wherein the halomethane is dichloromethane.

8. An electrolyte comprising the salt of claim 1 .

9. A cell comprising the electrolyte of claim 8 .

10. The cell of claim 9 , wherein the cell is a magnesium cell or a magnesium-ion cell.

11. A battery comprising the electrolyte of claim 8 .

12. The battery of claim 11 , wherein the battery is a magnesium battery or a magnesium-ion battery.

13. A method of making a salt of the general formula:
Mg 2+ (L y ) x (PF 6 ) 2   (i)

wherein x represent a number between 1 and 6,
L y represents a ligand independently selected from any one of the following compounds:
a halomethane,
a cyclic crown ether; or
a nitrile of the general formula R—C≡N; and

L y comprises a mixture of compounds L 1 and L 2 ; the method comprising:
providing Mg metal,
washing and activating the Mg metal in a first dry solution comprising a first compound (L 1 ),
treating the solution of activated Mg metal and first compound L 1 with NOPF 6 in a second dry solution comprising a second compound (L 2 ),
removing the residual solvent, and
recrystallizing the remaining solid to form the salt of Formula (i).

14. The method of claim 13 , wherein x is greater than 1, and L y represents a ligand selected from only one of the following compounds:
a halomethane,
a cyclic crown ether; or
a nitrile of the general formula R—C≡N.

15. The method of claim 13 , wherein x is equal to 6, L 1 and L 2 are each nitriles, and for L 1 and L 2 R independently represents an organic group selected from the following: methyl, ethyl, propyl, butyl, t butyl, pentyl, ethylene, propylene, butylene, pentylene, toluene, naphthalene, or phenyl.

16. The method of claim 15 , wherein L 1 and L 2 are the same nitrile.

17. The method of claim 16 , wherein L 1 and L 2 are both acetonitrile.

18. The method of claim 13 , wherein x is equal to 1 and L y is a cyclic crown ether selected from one of the following: [12]-crown-4, [18]-crown-6, [24]-crown-8.

19. The method of claim 13 , wherein the halomethane is dichloromethane.

Assignees

• Dyson Technology Ltd

Inventors

• Keyzer Evan
• Grey Clare
• Glass Hugh
• Wright Dominic

Classifications

• H01M10/054 Primary

  Accumulators with insertion or intercalation of metals other than lithium, e.g. with magnesium or aluminium · CPC title

• H01M6/162

  characterised by the electrolyte · CPC title

• H01M4/60 Primary

  of organic compounds · CPC title

• C07C253/30

  by reactions not involving the formation of cyano groups · CPC title

• H01M2300/0025

  Organic electrolyte · CPC title