Lithium secondary battery

Patent metadata

Field	Value
Publication number	US-12438153-B2
Application number	US-202017605375-A
Country	US
Kind code	B2
Filing date	Jul 21, 2020
Priority date	Jul 22, 2019
Publication date	Oct 7, 2025
Grant date	Oct 7, 2025

Abstract

A lithium secondary battery is disclosed herein. In some embodiments, a lithium secondary battery includes a positive electrode including a lithium transition metal oxide represented by Formula 1, a negative electrode, a non-aqueous electrolyte solution containing a lithium salt, a first non-aqueous solvent, and a second non-aqueous solvent, and a separator, wherein the first non-aqueous solvent is a carbonate-based organic solvent, the second non-aqueous solvent is a fluorine-based organic solvent, and a volume ratio of the first non-aqueous solvent to the second non-aqueous solvent is in a range of 5:5 to 9:1.

First claim

The invention claimed is:

1. A lithium secondary battery, comprising:
a positive electrode including a lithium transition metal oxide represented by Formula 1;
a negative electrode;
a separator disposed between the positive electrode and the negative electrode; and
a non-aqueous electrolyte solution containing a lithium salt, and a solvent,
wherein the lithium salt consists of LiN(SO 2 F) 2 (LiFSI), LiN(SO 2 CF 3 ) 2 (LITFSI), LiN(SO 2 C 2 F 5 ) 2 (LiBETI), or a combination thereof, and the lithium salt is in a concentration of 1.5 M to 2.8 M,
wherein the solvent consists of a first non-aqueous solvent and a second non-aqueous solvent, the first non-aqueous solvent is a carbonate-based organic solvent,
the second non-aqueous solvent is a fluorine-based organic solvent, and
a volume ratio of the first non-aqueous solvent to the second non-aqueous solvent is in a range of 7:3 to 9:1,
wherein the non-aqueous electrolyte solution does not comprise propylene carbonate, and
wherein the fluorine-based organic solvent is a fluorine-containing ether organic solvent represented by Formula 2,
Li(Ni a Co b Mn c )O 2   [Formula 1]

wherein, in Formula 1,
0.6≤a≤0.9, 0.05≤b<0.3, 0.05≤c<0.3, and a+b+c=1,
[R 1 —O—R 2 ] n   [Formula 2]

wherein, in Formula 2,
R 1 and R 2 are each independently an alkyl group having 1 to 10 carbon atoms substituted with at least one fluorine, and n is an integer of 1 to 10.

2. The lithium secondary battery of claim 1 , wherein the lithium transition metal oxide is Li(Ni 0.6 Mn 0.2 Co 0.2 )O 2 , Li(Ni 0.7 Mn 0.15 Co 0.15 )O 2 , or Li(Ni 0.8 Mn 0.1 Co 0.1 )O 2 .

3. The lithium secondary battery of claim 1 , wherein the lithium transition metal oxide is Li(Ni 0.7 Mn 0.15 Co 0.15 )O 2 or Li(Ni 0.8 Mn 0.1 Co 0.1 )O 2 .

4. The lithium secondary battery of claim 1 , wherein the lithium salt is LiFSI.

5. The lithium secondary battery of claim 1 , wherein, in Formula 2, R 1 is an alkyl group having 2 to 8 carbon atoms which is substituted with at least one fluorine, and R 2 is an alkyl group having 1 to 7 carbon atoms which is substituted with at least one fluorine.

6. The lithium secondary battery of claim 5 , wherein R 1 is an alkyl group having 2 to 6 carbon atoms which is substituted with at least one fluorine, and R 2 is an alkyl group having 1 to 5 carbon atoms which is substituted with at least one fluorine.

7. The lithium secondary battery of claim 1 , wherein the fluorine-containing ether organic solvent is 1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether or 1,1,2,2-tetrafluoroethyl 2,2,2-trifluoroethyl ether.

8. The lithium secondary battery of claim 1 , wherein the non-aqueous electrolyte solution further comprises at least one additive of a cyclic carbonate-based compound, a halogen-substituted carbonate-based compound, a sultone-based compound, a sulfate-based compound, a phosphate-based compound, a borate-based compound, a nitrile-based compound, an amine-based compound, a silane-based compound, or a lithium salt-based compound.

Assignees

• Lg Energy Solution Ltd

Inventors

• Han Jun Hyeok
• Ahn Kyoung Ho
• Lee Chul Haeng
• Park Sol Ji

Classifications

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M2300/0034

  Fluorinated solvents · CPC title

• H01M2004/028

  Positive electrodes · CPC title

• H01M2004/027

  Negative electrodes · CPC title

• H01M10/0569 Primary

  characterised by the solvents · CPC title