Electrolyte for lithium secondary battery and lithium secondary battery comprising same

Patent metadata

Field	Value
Publication number	US-11764404-B2
Application number	US-202117338084-A
Country	US
Kind code	B2
Filing date	Jun 3, 2021
Priority date	Oct 13, 2020
Publication date	Sep 19, 2023
Grant date	Sep 19, 2023

Abstract

The electrolyte for a lithium secondary battery includes: a lithium salt; a solvent; and a functional additive, wherein the functional additive includes: at least one high-voltage additive selected from a group consisting of lithium bis(phthalato)borate, represented by the following formula 1; hexafluoroglutaric anhydride, represented by the following formula 2; and phosphoric acid tris(2,2,2-trifluoroethyl)ester, represented by the following formula 3:

First claim

What is claimed is:

1. An electrolyte for a lithium secondary battery, the electrolyte comprising:
a lithium salt;
a solvent; and
a functional additive,
wherein the functional additive comprises: lithium bis(phthalato)borate, represented by the following formula 1; hexafluoroglutaric anhydride, represented by the following formula 2; and phosphoric acid tris(2,2,2-trifluoroethyl)ester, represented by the following formula 3:

2. The electrolyte of claim 1 , wherein the functional additive is added in a total amount of 0.5-3.0 wt %, based on a total weight of the electrolyte.

3. The electrolyte of claim 1 , wherein the electrolyte comprises:
0.5-1.0 wt % of the lithium bis(phthalato)borate,
0.25-1.0 wt % of the hexafluoroglutaric anhydride, and
0.5-1.0 wt % of the phosphoric acid tris(2,2,2-trifluoroethyl)ester, based on a total weight of the electrolyte.

4. The electrolyte of claim 1 , wherein the functional additive further comprises vinylene carbonate (VC).

5. The electrolyte of claim 4 , wherein the vinylene carbonate (VC) is added in an amount of 0.5-3.0 wt %, based on a total weight of the electrolyte.

6. The electrolyte of claim 1 , wherein the lithium salt comprises LiPF 6 , LiBF 4 , LiClO 4 , LiCl, LiBr, LiI, LiB 10 Cl 10 , LiCF 3 SO 3 , LiCF 3 CO 2 , LiAsF 6 , LiSbF 6 , LiAlCl 4 , CH 3 SO 3 Li, CF 3 SO 3 Li, LiN(SO 2 C 2 F 5 ) 2 , Li(CF 3 SO 2 ) 2 N, LiC 4 F 9 SO 3 , LiB(C 6 H 5 ) 4 , Li(SO 2 F) 2 N (LiFSI), (CF 3 SO 2 ) 2 NLi, or a combination thereof.

7. The electrolyte of claim 1 , wherein the solvent comprises a carbonate-based solvent, an ester-based solvent, an ether-based solvent, a ketone-based solvent, or a combination thereof.

8. A lithium secondary battery comprising:
an electrolyte comprising:
a lithium salt;
a solvent; and
a functional additive,
wherein the functional additive comprises: lithium bis(phthalato)borate, represented by the following formula 1; hexafluoroglutaric anhydride, represented by the following formula 2; and phosphoric acid tris(2,2,2-trifluoroethyl)ester, represented by the following formula 3:

9. The lithium secondary battery of claim 8 , further comprising:
a positive electrode containing a positive electrode active material comprising Ni, Co, and Mn;
a negative electrode containing at least one negative electrode active material comprising a carbon (C)-based material or silicon (Si)-based material; and
a separator interposed between the positive electrode and the negative electrode.

10. The lithium secondary battery of claim 8 , wherein the electrolyte comprises:
0.5-1.0 wt % of the lithium bis(phthalato)borate,
0.25-1.0 wt % of the hexafluoroglutaric anhydride, and
0.5-1.0 wt % of the phosphoric acid tris(2,2,2-trifluoroethyl)ester, based on a total weight of the electrolyte.

Assignees

• Hyundai Motor Co Ltd
• Kia Corp
• Iac In Nat Univ Chungnam

Inventors

• Kim Ko Eun
• Oh Seung Min
• Lee Yoon Sung
• Rhee Jun Ki
• Ban Sung Ho
• Song Seung Wan
• Chung Gyeong Jun

Classifications

• H01M10/0567 Primary

  characterised by the additives · CPC title

• H01M10/0569 Primary

  characterised by the solvents · CPC title

• H01M2300/0028

  characterised by the solvent · CPC title

• H01M10/0568

  characterised by the solutes · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title