Non-aqueous electrolyte for lithium secondary battery and lithium secondary battery comprising same

Patent metadata

Field	Value
Publication number	US-11626619-B2
Application number	US-201816642673-A
Country	US
Kind code	B2
Filing date	Aug 1, 2018
Priority date	Sep 6, 2017
Publication date	Apr 11, 2023
Grant date	Apr 11, 2023

Abstract

The present invention relates to a non-aqueous electrolyte for a lithium secondary battery and a lithium secondary battery comprising same. The non-aqueous electrolyte comprises: a non-aqueous organic solvent; a lithium salt; a first additive containing at least one compound among compounds represented by chemical formulas 1 to 4; and a second additive containing at least one compound among compounds represented by chemical formula 5 or 6.

First claim

The invention claimed is:

1. A non-aqueous electrolyte for a lithium secondary battery, the electrolyte comprising:
a non-aqueous organic solvent;
a lithium salt;
a first additive comprising at least one of compounds represented by Chemical Formulae 1 to 4; and
a second additive including a compound represented by Chemical Formula 5 or 6:

wherein, in Chemical Formulae 1 to 4,
R 1 to R 8 are independently a substituted or unsubstituted, primary, secondary, or tertiary alkyl group, a substituted or unsubstituted alkenyl group, or a substituted or unsubstituted aryl group,
R 9 is a substituted or unsubstituted, primary, secondary, or tertiary alkyl group or a substituted or unsubstituted aryl group,
X is hydrogen or a halogen atom,
n is an integer of 0 to 3, and
m1 and m2 are independently an integer of 0 to 3,

wherein, in Chemical Formulae 5 and 6,
R 10 to R 27 are independently a substituted or unsubstituted, primary, secondary, or tertiary alkyl group, a substituted or unsubstituted alkenyl group, or a substituted or unsubstituted aryl group.

2. The non-aqueous electrolyte for the lithium secondary battery of claim 1 , wherein an amount of the first additive is 0.1 wt % to 10 wt % based on a total weight of the electrolyte.

3. The non-aqueous electrolyte for the lithium secondary battery of claim 1 , wherein an amount of the first additive is 0.5 wt % to 7 wt % based on a total weight of the electrolyte.

4. The non-aqueous electrolyte for the lithium secondary battery of claim 1 , wherein an amount of the second additive is 0.1 wt % to 10 wt % based on a total weight of the electrolyte.

5. The non-aqueous electrolyte for the lithium secondary battery of claim 1 , wherein an amount of the second additive is 0.5 wt % to 7 wt % based on a total weight of the electrolyte.

6. The non-aqueous electrolyte for the lithium secondary battery of claim 1 , wherein a mixing ratio of the first additive and the second additive is a weight ratio of 10:1 to 0.08:1.

7. The non-aqueous electrolyte for the lithium secondary battery of claim 1 , wherein a mixing ratio of the first additive and the second additive is a weight ratio of 7:1 to 0.1:1.

8. A lithium secondary battery comprising
a negative electrode including negative active material;
a positive electrode including a positive active material; and
the non-aqueous electrolyte of claim 1 .

9. The lithium secondary battery of claim 8 , wherein the positive active material is a lithium nickel-based compound.

10. The lithium secondary battery of claim 9 , wherein the positive active material is a lithium nickel-based compound of Chemical Formula 7:
Li a1 Ni x1 Co y1 A z1 O 2   [Chemical Formula 7]

wherein, in Chemical Formula 7,
0.9≤a1≤1.1, 0.6≤x1≤0.90, 0.01≤y1≤0.3, 0.01≤z1≤0.3, x1+y1+z1 =1, and A is Mn or Al.

11. The non-aqueous electrolyte for the lithium secondary battery of claim 1 , wherein R 10 to R 27 are independently a substituted or unsubstituted alkenyl group or a substituted or unsubstituted aryl group.

Assignees

• Samsung Sdi Co Ltd

Inventors

• Kim Yunhee
• Kim Kyoung Soo
• You Yongchan
• Cho Erang
• Choi Seonju

Classifications

• H01M4/525

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title

• C07F7/0834

  Compounds having one or more O-Si linkage (for compounds with C-O-Si linkages see C07F7/18) · CPC title

• H01M2300/0025

  Organic electrolyte · CPC title

• H01M10/0567 Primary

  characterised by the additives · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title