Electrolytic solution, and preparation method thereof and application thereof

Patent metadata

Field	Value
Publication number	US-12322753-B2
Application number	US-202217591198-A
Country	US
Kind code	B2
Filing date	Feb 2, 2022
Priority date	Mar 9, 2020
Publication date	Jun 3, 2025
Grant date	Jun 3, 2025

Abstract

An electrolytic solution includes an organic solvent, an electrolyte, and an additive. The additive includes a first compound represented by Formula 1, where R 1 is selected from one of a single bond, substituted or unsubstituted alkoxy, C1-C6 alkylene, and C2-C6 alkenyl; R 2 and R 3 each are independently selected from one of substituted or unsubstituted alkoxy, C1-C6 alkylene, and C2-C6 alkenyl; and R 4 is B or P. Since the first compound includes an N-containing group that may be combined with a protonic acid in the electrolytic solution, the electrolytic solution have good stability; moreover, the cycle performance of a lithium secondary battery is improved.

First claim

What is claimed is:

1. An electrolytic solution, comprising an organic solvent and an electrolyte, wherein the electrolytic solution further comprises an additive, the additive comprises a first compound represented by Formula 1, wherein R 1 is selected from one of a single bond, substituted or unsubstituted alkoxy, C1-C6 alkylene, and C2-C6 alkenyl; R 2 and R 3 each are independently selected from one of substituted or unsubstituted alkoxy, C1-C6 alkylene, and C2-C6 alkenyl; and R 4 is B or P,

wherein the first compound is at least one of compounds represented by Formula 1-1, Formula 1-2, Formula 1-3 and Formula 1-4,

2. The electrolytic solution according to claim 1 , wherein the additive further comprises a second compound, which is one or more of nitrile compound, sulfur-containing compound, phosphate ester compound, borate ester compound, lithium salt compound and carbonate ester compound.

3. The electrolytic solution according to claim 2 , wherein the nitrile compound is one or more of succinonitrile, glutaronitrile, adiponitrile, pimelonitrile, octanedinitrile, sebaconitrile, octadecane dinitrile, glycerol trinitrile, ethylene glycol bis(propionitrile) ether, fumaric acid dinitrile, ethoxypentafluorophosphonitrile, 1,3,6-hexanetrinitrile; the sulfur-containing compound is one or more of 1,3-propanesultone, 1,3-propylenesultone, and ethylene sulfate; the phosphate ester compound is one or more of tris(trimethylsilyl) phosphate, triallyl phosphate, trimethyl phosphate, triethyl phosphate and tripropyl phosphate; the borate ester compound is one or more of tris(trimethylsilyl) borate ester and trimethyl borate ester; the lithium salt compound is one or more of lithium difluorophosphate, lithium bis(trifluoromethylsulfonyl)imide, lithium bis(fluorosulfonyl)imide, lithium difluorobis(oxalato)phosphate, lithium difluoro (oxalato) borate and lithium bis(oxalato) borate; and the carbonate compound is one or more of ethylene carbonate, fluoroethylene carbonate and vinylethylene carbonate.

4. The electrolytic solution according to claim 1 , wherein a mass of the first compound is 0.1-10% of a mass of the electrolytic solution.

5. The electrolytic solution according to claim 1 , wherein a mass of the first compound is 0.2-2% of a mass of the electrolytic solution.

6. The electrolytic solution according to claim 2 , wherein a mass of the second compound is 0.1-20% of a mass of the electrolytic solution.

7. The electrolytic solution according to claim 2 , wherein a mass of the second compound is 1-6% of a mass of the electrolytic solution.

8. A method for preparing an electrolytic solution according to claim 1 , wherein the electrolytic solution is obtained by mixing an additive, an electrolyte and an organic solvent,
wherein the additive comprises a first compound represented by Formula 1, wherein R 1 is selected from one of a single bond, substituted or unsubstituted alkoxy, C1-C6 alkylene, and C2-C6 alkenyl; R 2 and R 3 each are independently selected from one of substituted or unsubstituted alkoxy, C1-C6 alkylene, and C2-C6 alkenyl; and R 4 is B or P,

wherein the first compound is at least one of compounds represented by Formula 1-1, Formula 1-2, Formula 1-3 and Formula 1-4.

9. The method according to claim 8 , wherein the additive further comprises a second compound, which is one or more of nitrile compound, sulfur-containing compound, phosphate ester compound, borate ester compound, lithium salt compound and carbonate ester compound.

10. The method according to claim 9 , wherein the nitrile compound is one or more of succinonitrile, glutaronitrile, adiponitrile, pimelonitrile, octanedinitrile, sebaconitrile, octadecane dinitrile, glycerol trinitrile, ethylene glycol bis(propionitrile) ether, fumaric acid dinitrile, ethoxypentafluorophosphonitrile, 1,3,6-hexanetrinitrile; the sulfur-containing compound is one or more of 1,3-propanesultone, 1,3-propylenesultone, and ethylene sulfate; the phosphate ester compound is one or more of tris(trimethylsilyl) phosphate, triallyl phosphate, trimethyl phosphate, triethyl phosphate and tripropyl phosphate; the borate ester compound is one or more of tris(trimethylsilyl) borate ester and trimethyl borate ester; the lithium salt compound is one or more of lithium difluorophosphate, lithium bis(trifluoromethylsulfonyl)imide, lithium bis(fluorosulfonyl)imide, lithium difluorobis(oxalato)phosphate, lithium difluoro (oxalato) borate and lithium bis(oxalato) borate; and the carbonate compound is one or more of ethylene carbonate, fluoroethylene carbonate and vinylethylene carbonate.

11. The method according to claim 8 , wherein a mass of the first compound is 0.1-10% of a mass of the electrolytic solution.

12. The method according to claim 8 , wherein a mass of the first compound is 0.2-2% of a mass of the electrolytic solution.

13. The method according to claim 9 , wherein a mass of the second compound is 0.1-20% of a mass of the electrolytic solution.

14. The method according to claim 9 , wherein a mass of the second compound is 1-6% of a mass of the electrolytic solution.

15. A lithium secondary battery, comprising the electrolytic solution according to claim 1 .

Assignees

• Zhuhai Cosmx Battery Co Ltd

Inventors

• Liao Bo
• Li Suli
• Wang Hai
• Xu Yanming
• Li Junyi

Classifications

• H01M2300/0028

  characterised by the solvent · CPC title

• H01M10/0569

  characterised by the solvents · CPC title

• H01M10/0568

  characterised by the solutes · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M2300/004

  Three solvents · CPC title