Electrolyte and electrochemical device

Patent metadata

Field	Value
Publication number	US-12444770-B2
Application number	US-201916962777-A
Country	US
Kind code	B2
Filing date	Dec 26, 2019
Priority date	Dec 26, 2019
Publication date	Oct 14, 2025
Grant date	Oct 14, 2025

Abstract

An electrochemical device including a positive electrode, a negative electrode and an electrolyte, wherein the negative electrode comprises a negative electrode active material layer, including a negative electrode active material, wherein the negative electrode active material includes a silicon-containing compound; and the negative electrode active material further includes, on the surface, a protective layer including a compound having an S═O bond.

First claim

What is claimed is:

1. An electrochemical device comprising a positive electrode, a negative electrode and an electrolyte, wherein
the negative electrode comprises a negative electrode active material layer, comprising a negative electrode active material, wherein the negative electrode active material comprises a silicon-containing compound; and
the negative electrode active material further comprises, on the surface, a protective layer comprising a compound having an S═O bond,
wherein the silicon-containing compound is coated with a layer of Me y O z , wherein 1≤y≤2, 1≤z≤3, and Me is at least one selected from Ti, Al, Zr or Zn, and the layer of Me y O z has a thickness of 5 nm to 100 nm; and
wherein the electrolyte comprises at least one sulfonic anhydride compound of Formula I or Formula II:

wherein R 1 to R 18 are each independently selected from hydrogen, halo, substituted or unsubstituted C 1 -C 7 alkyl, substituted or unsubstituted C 2 -C 7 alkenyl, substituted or unsubstituted C 2 -C 7 alkynyl, substituted or unsubstituted C 6 -C 10 aryl, substituted or unsubstituted C 1 -C 7 alkoxy, or substituted or unsubstituted C 6 -C 10 aryloxy; and
wherein when substituted, the substituent is halo or cyano; and
wherein the electrolyte further comprises a fluorinated additive, wherein the fluorinated additive comprises at least one of compound 13, compound 15 or compound 19; and the fluorinated additive accounts for no less than about 5 wt % based on a weight of the electrolyte;

and
wherein the electrolyte further comprises an additive A, wherein the additive A comprises at least one of vinylene carbonate, vinyl sulfate, butanedinitrile or adiponitrile, and wherein the additive A accounts for 0.1 wt % to 10 wt % based on a weight of the electrolyte.

2. The electrochemical device according to claim 1 , wherein the sulfonic anhydride compound comprises at least one of:

and
wherein the sulfonic anhydride compound accounts for 0.01 wt % to 2 wt % based on a weight of the electrolyte.

3. The electrochemical device according to claim 1 , wherein the silicon-containing compound accounts for 1 to 90 wt % based on a total weight of the negative electrode active material.

4. The electrochemical device according to claim 1 , wherein the negative electrode active material layer comprises carbon nanotubes having a tube diameter of 1 nm to 10 nm, and a tube length of 1 micron to 50 microns.

5. The electrochemical device according to claim 4 , wherein a weight ratio of the silicon-containing compound to the carbon nanotubes is 50 to 300, based on a total weight of the negative electrode active material.

6. The electrochemical device according to claim 1 , wherein a load of the negative electrode active material layer on the negative electrode is 10 mg/cm 2 to 30 mg/cm 2 .

7. The electrochemical device according to claim 1 , wherein a weight ratio P of the fluorinated additive to the sulfonic anhydride compound meets: 1<P<50.

8. An electronic device, comprising an electrochemical device, wherein the electrochemical device comprises a positive electrode, a negative electrode and an electrolyte, wherein
the negative electrode comprises a negative electrode active material layer, comprising a negative electrode active material, wherein the negative electrode active material comprises a silicon-containing compound; and
the negative electrode active material further comprises, on the surface, a protective layer comprising a compound having an S═O bond,
wherein the silicon-containing compound is coated with a layer of Me y O z , wherein 1≤y≤2, 1≤z≤3, and Me is at least one selected from TI, Al, Zr or Zn, and the layer of Me y O z has a thickness of 5 nm to 100 nm, and
wherein the electrolyte comprises at least one sulfonic anhydride compound of Formula I or Formula II:

wherein R 1 to R 18 are each independently selected from hydrogen, halo, substituted or unsubstituted C 1 -C 7 alkyl, substituted or unsubstituted C 2 -C 7 alkenyl, substituted or unsubstituted C 2 -C 7 alkynyl, substituted or unsubstituted C 6 -C 10 aryl, substituted or unsubstituted C 1 -C 7 alkoxy, or substituted or unsubstituted C 6 -C 10 aryloxy; and
wherein when substituted, the substituent is halo or cyano; and
wherein the electrolyte further comprises a fluorinated additive, wherein the fluorinated additive comprises at least one of compound 13, compound 15 or compound 19; and the fluorinated additive accounts for no less than about 5 wt % based on a weight of the electrolyte;

and
wherein the electrolyte further comprises an additive A, wherein the additive A comprises at least one of vinylene carbonate, vinyl sulfate, butanedinitrile or adiponitrile, and wherein the additive A accounts for 0.1 wt % to 10 wt % based on a weight of the electrolyte.

9. The electronic device according to claim 8 , wherein the sulfonic anhydride compound comprises at least one of:

and
wherein the sulfonic anhydride compound accounts for 0.01 wt % to 2 wt % based on a weight of the electrolyte.

10. The electronic device according to claim 8 , wherein the silicon-containing compound accounts for 1 to 90 wt % based on a total weight of the negative electrode active material.

11. The electronic device according to claim 8 , wherein the negative electrode active material layer comprises carbon nanotubes having a tube diameter of 1 nm to 10 nm, and a tube length of 1 micron to 50 microns.

12. The electrochemical device according to claim 1 , wherein each of Formula I, II, and III contains more than 5 carbon atoms in total.

13. The electrochemical device according to claim 1 , wherein the fluorinated additive comprises at least one of the fluorinated ether having 2 to 7 carbon atoms or the fluorinated carboxylate having 2 to 6 carbon atoms.

Assignees

• Ningde Amperex Technology Ltd

Inventors

• Tang Chao
• Liu Junfei
• Zhang Lilan
• Zheng Jianming

Classifications

• H01M2004/028

  Positive electrodes · CPC title

• H01M2004/027

  Negative electrodes · CPC title

• H01M2004/021

  Physical characteristics, e.g. porosity, surface area · CPC title

• H01M10/0569

  characterised by the solvents · CPC title

• H01M10/0568

  characterised by the solutes · CPC title