Electrolytic solution and lithium metal battery containing the same, battery module, battery pack, and device

Patent metadata

Field	Value
Publication number	US-11888115-B2
Application number	US-202117550946-A
Country	US
Kind code	B2
Filing date	Dec 14, 2021
Priority date	Sep 9, 2019
Publication date	Jan 30, 2024
Grant date	Jan 30, 2024

Abstract

This application provides an electrolytic solution and a lithium metal battery containing the electrolytic solution. The electrolytic solution includes a lithium salt, an organic solvent, and an additive. The additive includes a sultam compound represented by Structural Formula I. R is selected from substituted or unsubstituted C 1 to C 10 hydrocarbyls, where a substituent is selected from a phenyl, C 1 to C 6 alkyls, or C 1 to C 6 alkenyls. X is a sulfur atom or a phosphorus atom. R 1 and R 2 each are independently selected from an oxygen atom, a fluorine atom, a chlorine atom, a bromine atom, and substituted or unsubstituted C1 to C10 hydrocarbyls. Both R 1 and R 2 are not oxygen atoms concurrently.

First claim

What is claimed is:

1. An electrolytic solution, comprising a lithium salt, an organic solvent, and an additive, wherein the additive comprises a sultam compound represented by Structural Formula I:

wherein
R is selected from substituted or unsubstituted C 1 to C 10 hydrocarbyls, wherein a substituent is selected from a phenyl, C 1 to C 6 alkyls, or C 1 to C 6 alkenyls;
X is a sulfur atom or a phosphorus atom; and
R 1 and R 2 each are independently selected from an oxygen atom, a fluorine atom, a chlorine atom, a bromine atom, and substituted or unsubstituted C 1 to C 10 hydrocarbyls, wherein a substituent contains one or more of elements fluorine, chlorine, bromine, iodine, nitrogen, oxygen, sulfur, silicon, boron, and phosphorus; and both R 1 and R 2 are not oxygen atoms concurrently.

2. The electrolytic solution according to claim 1 , wherein the additive comprises a sultam compound represented by Structural Formula I-1:

wherein, X is a phosphorus atom, and R 1 and R 2 each are independently selected from F, Cl, Br, or halogenated C 1 to C 4 hydrocarbyls,
or, X is a sulfur atom, R 2 is an oxygen atom, and R 1 is selected from F, Cl, Br, or halogenated or unsubstituted C 1 to C 4 hydrocarbyls; and
n is 1, 2, 3, or 4.

3. The electrolytic solution according to claim 1 , wherein the additive comprises the sultam compound represented by Structural Formula I-1:

wherein, X is a phosphorus atom, and R 1 and R 2 each are independently selected from F, Cl, Br, or halogenated C 1 to C 4 hydrocarbyls,
or, X is a sulfur atom, R 2 is an oxygen atom, and R 1 is selected from F, Cl, Br, or halogenated C 1 to C 4 hydrocarbyls; and
n is 1, 2, or 3.

4. The electrolytic solution according to claim 1 , wherein X is a phosphorus atom, and R 1 or R 2 is selected from F, —CH 3 , —C 2 H 5 , —C 3 H 7 , —C 4 H 9 , —CF 3 , —C 2 F 5 , linear —C 3 F 7 , linear —C 4 F 9 , —CH 2 CF 3 , and —CH(CF 3 ) 2 ; or X is a sulfur atom, R 2 is an oxygen atom, and R 1 is selected from F, —CH 3 , —C 2 H 5 , —C 3 H 7 , —C 4 H 9 , —CF 3 , —C 2 F 5 , linear —C 3 F 7 , linear —C 4 F 9 , —CH 2 CF 3 , and —CH(CF 3 ) 2 .

5. The electrolytic solution according to claim 1 , wherein X is a sulfur atom, R is —CH 2 CH 2 — or —CH(Ph)CH 2 —, R 2 is an oxygen atom, and R 1 is F or Cl; or X is a phosphorus atom, R is —CH 2 CH 2 —, and R 1 and R 2 each are independently selected from F.

6. The electrolytic solution according to claim 1 , wherein, based on a total mass of the electrolytic solution, a mass percent of the sultam compound in the electrolytic solution is 0.5% to 15%.

7. The electrolytic solution according to claim 1 , wherein, based on the total mass of the electrolytic solution, a ratio of the content of the sultam compound to a content of the lithium salt is 0.04 to 0.06,
the content of the sultam compound is measured by a mass percent; and
the content of the lithium salt is measured by a molar concentration.

8. The electrolytic solution according to claim 1 , wherein the electrolytic solution further contains a film-forming additive, and the film-forming additive is fluoroethylene carbonate.

9. The electrolytic solution according to claim 8 , wherein a ratio of a content C1 of the sultam compound, a content C2 of the fluoroethylene carbonate, and a content L of the lithium salt satisfies the following relational expression:
38 ≤L ( C 1 +C 2)/ C 1 C 2≤42;

wherein, C1 and C2 are measured by mass percent; and
L is measured by a molar concentration.

10. A lithium metal battery, comprising a positive electrode, an electrolytic solution, a negative electrode, and a separator located between the positive electrode and the negative electrode, wherein the electrolytic solution is the electrolytic solution according to claim 1 , and the negative electrode comprises a lithium-containing metal material.

11. The lithium metal battery according to claim 10 , wherein the lithium-containing metal material is metallic lithium or a lithium alloy.

12. The lithium metal battery according to claim 11 , wherein the lithium alloy comprises one or more of a Li—Sn alloy, a Li—Sn—O alloy, a Li—Mg alloy, a Li—B alloy, and a Li—Al alloy.

13. The lithium metal battery according to claim 10 , wherein a moisture content in the positive electrode plate is 1 mg/Ah to 100 mg/Ah, and a molar ratio of the sultam compound in the electrolytic solution to moisture in the positive electrode plate is 0.1:1 to 10:1.

14. The lithium metal battery according to claim 13 , wherein the molar ratio of the sultam compound in the electrolytic solution to the moisture in the positive electrode plate is 0.8:1 to 1.2:1.

15. The lithium metal battery according to claim 10 , wherein an injection volume of the electrolytic solution is 0.5 g/Ah to 5 g/Ah.

16. The lithium metal battery according to claim 15 , wherein the injection volume of the electrolytic solution is 2 g/Ah to 3 g/Ah.

17. The lithium metal battery according to claim 10 , wherein an electrolyte interface film on a surface of the lithium-containing metal material contains sulfate, sulfonate lithium salt, and polysulfonimide.

18. The lithium metal battery according to claim 10 , wherein the positive electrode comprises a positive active material, and the positive active material is a lithium transition metal composite oxide.

19. A battery module, comprising the lithium metal battery according to claim 10 .

20. A device, comprising the lithium metal battery according to claim 10 .

Assignees

• Contemporary Amperex Technology Co Ltd

Inventors

• Liu Chengyong
• Guo Yongsheng
• Liang Chengdu
• Fan Quan

Classifications

• H01M10/0567 Primary

  characterised by the additives · CPC title

• H01M4/134

  Electrodes based on metals, Si or alloys · CPC title

• H01M4/382

  Lithium (H01M4/405 takes precedence) · CPC title

• H01M10/052 Primary

  Li-accumulators · CPC title

• H01M10/0569

  characterised by the solvents · CPC title