Electrolytic solution, secondary battery, and power consumption apparatus

Patent metadata

Field	Value
Publication number	US-12500273-B2
Application number	US-202218072720-A
Country	US
Kind code	B2
Filing date	Dec 1, 2022
Priority date	Oct 15, 2021
Publication date	Dec 16, 2025
Grant date	Dec 16, 2025

Abstract

The present application provides an electrolytic solution, a secondary battery, and a power consumption apparatus. The electrolytic solution may include a solvent and an additive; the solvent may include a compound of formula I, and a mass percentage of the compound of formula I in the solvent may be 35% or more; in formula I, R 1 and R 2 are each independently selected from any one of a hydrogen atom, a C1-C3 chain alkyl group, and a C2-C3 alkenyl group; and the additive may include a compound of formula II, and in formula II, R 3 , R 4 , and R 5 are each independently selected from any one of a hydrogen atom, a fluorine atom, a phenyl group, a cyano group, a C1-C6 chain alkyl group, a C3-C6 cyclic alkyl group, and a C2-C6 alkenyl group.

First claim

What is claimed is:

1 . An electrolytic solution, comprising a solvent and an additive,
wherein the solvent comprises a compound of formula I, and a mass percentage of the compound of formula I in the solvent is 35% or more,

wherein R 1 , and R 2 are each independently selected from any one of a hydrogen atom, a C1-C3 chain alkyl group, and a C2-C3 alkenyl group;
the additive comprises a compound of formula II,

wherein R 3 , R 4 , and R 5 are each independently selected from any one of a hydrogen atom, a fluorine atom, a phenyl group, a cyano group, a C1-C6 chain alkyl group, a C3-C6 cyclic alkyl group, and a C2-C6 alkenyl group,
wherein the electrolytic solution satisfies 11≤a/b≤35,
wherein a is the mass percentage of the compound of formula I in the solvent, and
b is a mass percentage of the compound of formula II in the electrolytic solution.

2 . The electrolytic solution according to claim 1 , wherein the mass percentage of the compound of formula I in the solvent is 40%-70%.

3 . The electrolytic solution according to claim 1 , wherein a mass percentage of the compound of formula II in the electrolytic solution is 9% or less.

4 . The electrolytic solution according to claim 3 , wherein the mass percentage of the compound of formula II in the electrolytic solution is 3%-5%.

5 . The electrolytic solution according to claim 1 , wherein the compound of formula I comprises at least one selected from methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl acrylate and ethyl acrylate.

6 . The electrolytic solution according to claim 1 , wherein the compound of formula II comprises at least one of biphenyl, fluorobenzene and cyclohexylbenzene.

7 . The electrolytic solution according to claim 1 , wherein the electrolytic solution comprises an electrolyte salt, and the electrolyte salt comprises a compound of formula III, and a molar percentage of the compound of formula III in the electrolyte salt is 10% or more,

wherein R 6 and R 7 are each independently an F atom or a fluoroalkyl group, R 6 and R 7 can also be linked to form a cycle.

8 . The electrolytic solution according to claim 7 , wherein the compound of formula III comprises at least one selected from lithium bisfluorosulfonimide and lithium bis(trifluoromethanesulfonyl)imide.

9 . The electrolytic solution according to claim 1 , wherein the solvent further comprises a carbonate, and a mass percentage of the carbonate in the solvent is 30% or more.

10 . The electrolytic solution according to claim 9 , wherein the mass percentage of the carbonate in the solvent is 35%-65%.

11 . The electrolytic solution according to claim 1 , wherein the solvent further comprises ethylene carbonate, and a mass percentage of the ethylene carbonate in the solvent is 30% or more.

12 . The electrolytic solution according to claim 1 , wherein the additive further comprises at least one selected from vinylene carbonate (VC), fluoroethylene carbonate (FEC), vinyl sulfate (DTD), 1,3-propane sultone (PS), lithium difluorobisoxalate phosphate (LiDFOP), lithium difluoro (oxalato) borate (LiDFOB), and lithium bis(oxalato) borate (LiBOB).

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

14 . The secondary battery according to claim 13 , wherein the secondary battery comprises a positive electrode sheet, the positive electrode sheet comprises a positive electrode film layer, the positive electrode film layer comprises a positive active material, and the positive active material comprises an olivine-structured lithium-containing phosphate.

15 . The secondary battery according to claim 14 , wherein the secondary battery makes true 1 g/1000 m 2 ≤L≤5 g/1000 m 2 ,
L=M1/[M2×B×(a+c)]*1000,

M1 is mass of the compound of formula II with a unit of g,
M2 is mass of the positive active material with a unit of g,
B is a specific surface area of the positive active material with a unit of m 2 /g,
a is a mass percentage of the compound of formula I in the solvent, and
c is a molar percentage of the compound of formula III in the electrolyte salt.

16 . The secondary battery according to claim 15 , wherein 8 m 2 /g≤B≤16 m 2 /g.

17 . The secondary battery according to claim 15 , wherein a thickness of the single-faced positive electrode film layer is 0.08 mm or more.

18 . A power consumption apparatus comprising the secondary battery according to claim 13 .

19 . The electrolytic solution according to claim 1 , wherein the mass percentage of the compound of formula I in the solvent is 60% or more.

Assignees

• Contemporary Amperex Technology Hong Kong Ltd

Inventors

• Huang Lei
• Han Changlong
• Wu Zeli
• Zhang Cuiping

Classifications

• H01M4/5825

  Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines · CPC title

• H01M2004/028

  Positive electrodes · CPC title

• H01M2300/0051

  Carbonates · CPC title

• H01M2300/0037

  Mixture of solvents · CPC title

• H01M10/0568

  characterised by the solutes · CPC title