Organic electrolyte and secondary battery comprising same

Patent metadata

Field	Value
Publication number	US-2024063437-A1
Application number	US-202118260628-A
Country	US
Kind code	A1
Filing date	Nov 24, 2021
Priority date	Jan 8, 2021
Publication date	Feb 22, 2024
Grant date	—

Abstract

An organic electrolyte includes: a lithium salt, a non-aqueous solvent; and a nitrile-based compound represented by a certain formula, wherein the non-aqueous solvent includes a fluorinated cyclic carbonate compound and a fluorinated chain carbonate compound. A secondary battery including such an organic electrolyte is also disclosed.

First claim

1 . An organic electrolyte comprising:
a lithium salt; a non-aqueous solvent comprising a fluorinated cyclic carbonate compound and a fluorinated chain carbonate compound; and a nitrile-based compound represented by Formula 1 below:
N≡C-A 1 -C≡N   Formula 1

wherein, in Formula 1, A 1 is a C 4 -C 10 alkylene group substituted or unsubstituted with at least one of —F, —Cl, —Br, —I, a cyano group, a C 1 -C 10 alkyl group, a C 3 -C 7 cycloalkyl group, or a C 1-C10 alkoxy group.

2 . The organic electrolyte of claim 1 , wherein the C 4 -C 10 alkylene group is a linear or branched C 4 -C 10 alkylene group.

3 . The organic electrolyte of claim 2 , wherein the C 4 -C 10 alkylene group is a linear or branched C 6 -C 8 alkylene group.

4 . The organic electrolyte of claim 1 , wherein the nitrile-based compound comprises at least one of 1,4-dicyanobutane, 1,5-dicyanopentane, 1,6-dicyanohexane, 1,7-dicyanoheptane, 1,8-dicyanooctane, 1,9-dicyanononane, or 1,10-dicyanodecane.

5 . The organic electrolyte of claim 1 , wherein a content of the nitrile-based compound is greater than 10 vol % and less than 80 vol % with respect to a total volume of the organic electrolyte.

6 . The organic electrolyte of claim 1 , wherein the lithium salt is LiPF 6 , LiBF 4 , LiSbF 6 , LiAsF 6 , LiClO 4 , LiCF 3 SO 3 , Li(CF 3 SO 2 ) 2 N, LiC 4 F 9 SO 3 , LiAlO 2 , LiAlC 4 , LiN(C x F 2x+1 SO 2 )(C y F 2y+1 SO 2 ), (wherein x and y are natural numbers), LiCl, LiI, or a mixture thereof.

7 . The organic electrolyte of claim 1 , wherein the lithium salt is contained in a concentration of 0.01 M to 1.0 M.

8 . The organic electrolyte of claim 1 , wherein the fluorinated cyclic carbonate compound is represented by Formula 2 below:

wherein, in Formula 2, A 2 is a C 1 -C 4 alkylene group substituted with at least one of —F, —Cl, —Br, —I, a cyano group, a C 1 -C 10 alkyl group, a C 3 -C 7 cycloalkyl group, and a C 1 -C 10 alkoxy group, and at least one substituents of A 2 is —F.

9 . The organic electrolyte of claim 8 , wherein A 2 is a C 2 -C 4 alkylene group substituted with at least one —F.

10 . The organic electrolyte of claim 1 , wherein the fluorinated cyclic carbonate compound comprises at least one of a fluoroethylene carbonate compound, a difluoroethylene carbonate compound, a fluoropropylene carbonate compound, a difluoropropylene carbonate compound, or a trifluoropropylene carbonate compound.

11 . The organic electrolyte of claim 1 , wherein the fluorinated cyclic carbonate compound is contained in a content that is greater than 15 vol % and less than 55 vol % with respect to 100 vol % of the organic electrolyte.

12 . The organic electrolyte of claim 1 , wherein the fluorinated chain carbonate compound is represented by Formula 3 below:

wherein, in Formula 3, L 1 and L 2 are each independently a single bond or a C 1 -C 10 alkylene group substituted or unsubstituted with at least one of −F, —Cl, —Br, —I, a cyano group, a C 1 -C 10 alkyl group, a C 3 -C 7 cycloalkyl group, or a C 1 -C 10 alkoxy group, a1 and a2 are independently an integer selected from 1 to 3, R 1 and R 2 are each independently a C 1 -C 10 alkyl group unsubstituted or substituted with at least one of —F, —Cl, —Br, —I, a cyano group, a C 1 -C 10 alkyl group, a C 3 -C 7 cycloalkyl group, or a C 1 -C 10 alkoxy group, and at least one of L 1 , L 2, R 1 , or R 2 is substituted with —F.

13 . The organic electrolyte of claim 12 , R 1 and R 2 are each independently a C 1 -C 10 alkyl group in which at least one —F is substituted.

14 . The organic electrolyte of claim 12 , wherein R 1 and R 2 are each independently CFHCH 3 , —CF 2 CH 3 , —CH 2 CFH 2 , —CH 2 CF 2 H, —CH 2 CF 3 , —CFHCFH 2 , —CFHCF 2 H, —HCF 3 , —CF 2 CFH 2 , —CF 2 CF 2 H, or —CF 2 CF 3 .

15 . The organic electrolyte of claim 12 , wherein R 1 and R 2 are identical to each other.

16 . The organic electrolyte of claim 1 , wherein the fluorinated chain carbonate compound is contained in a content that is greater than 15 vol % and less than 55 vol % with respect to 100 vol % of the organic electrolyte.

17 . The organic electrolyte of claim 1 , wherein the fluorinated cyclic carbonate compound and the fluorinated chain carbonate compound are contained in a content that is greater than 30 vol % and less than 70 vol % with respect to a total volume of the organic electrolyte.

18 . The organic electrolyte of claim 1 , wherein the non-aqueous solvent further comprises at least one solvent selected from an ether-based solvent, an ester-based solvent, and a ketone-based solvent.

19 . A secondary battery comprising:
a positive electrode; a negative electrode; and the organic electrolyte of claim 1 .

20 . The secondary battery of claim 19 , wherein the secondary battery maintains an overvoltage of 0.3 V or less after being charged to 6 V.

Assignees

• Samsung Electronics Co Ltd

Inventors

• Bae Youngjoon
• Ma Sangbok
• Kim Taeyoung
• Lim Sungjin

Classifications

• H01M10/0569 Primary

  characterised by the solvents · CPC title

• H01M10/0568

  characterised by the solutes · CPC title

• H01M2300/0034

  Fluorinated solvents · CPC title

• H01M2300/004

  Three solvents · CPC title

• H01M10/0567 Primary

  characterised by the additives · CPC title