Lithium secondary battery

Patent metadata

Field	Value
Publication number	US-2020373616-A1
Application number	US-201816638522-A
Country	US
Kind code	A1
Filing date	Aug 1, 2018
Priority date	Sep 6, 2017
Publication date	Nov 26, 2020
Grant date	—

Abstract

A lithium secondary battery is disclosed. The lithium secondary battery according to an embodiment comprises: an anode; a cathode comprising a cathode active material; and a nonaqueous electrolyte, wherein the nonaqueous electrolyte comprises a nonaqueous organic solvent, a lithium salt, a first additive comprising at least one of compounds represented by chemical formulae 1-4, and a second additive comprising at least one of compounds represented by chemical formulae 5 to 6, and the cathode active material can comprise a compound containing 60 mol % or greater of Ni.

First claim

1 . A lithium secondary battery comprising
an anode; a cathode comprising a cathode active material; and a non-aqueous electrolyte, wherein the non-aqueous electrolyte comprises 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 comprising at least one of compounds represented by Chemical Formulae 5 to 6, the cathode active material comprises a compound comprising 60 mol % or greater of Ni:

wherein, in Chemical Formulae 1 to 4,
R 1 to R 9 are independently a primary, secondary, or tertiary alkyl group, an alkenyl group, or an 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,
Li α PO 3 F β   [Chemical Formula 5]

Li γ PO 2 F δ   [Chemical Formula 6]

wherein, in Chemical Formulae 5 and 6,
α and γ are independently an integer of 1 or more, β and δ are independently an integer of 0 or more, α+β≤3, and γ+δ≤3.

2 . The lithium secondary battery of claim 1 , wherein an amount of the first additive is 0.05 wt % to 10 wt % based on a total weight of the electrolyte.

3 . The lithium secondary battery of claim 1 , wherein an amount of the first additive is 0.2 wt % to 3 wt % based on a total weight of the electrolyte.

4 . The lithium secondary battery of claim 1 , wherein an amount of the second additive is 0.05 wt % to 15 wt % based on a total weight of the electrolyte.

5 . The lithium secondary battery of claim 1 , wherein an amount of the second additive is 0.2 wt % to 5 wt % based on a total weight of the electrolyte.

6 . The lithium secondary battery of claim 1 , wherein the first additive is at least one selected from bis(triethylsilyl) sulfate, bis(trimethylsilyl) sulfate, di-t-butylsilylbis(trifluoromethanesulfonate), trimethylsilyl methane sulfonate, trimethylsilyl ethanesulfonate, triethylsilyl methanesulfonate, trimethylsilyl benzene sulfonate, trimethylsilyl trifluoromethane sulfonate, triethylsilyl trifluoromethane sulfonate, and a combination thereof.

7 . The lithium secondary battery of claim 1 , wherein the second additive is at least one selected from LiPO 2 F 2 , LiPO 3 F 2 , and a combination thereof.

8 . The lithium secondary battery of claim 1 , wherein the compound comprising 60 mol % or greater of Ni is represented by Chemical Formula 7:
Li a Ni x Co y Me z O 2   [Chemical Formula 7]
wherein, in Chemical Formula 7, 0.9≤a≤1.1, 0.6≤x≤0.98, 0<y≤0.3, 0<z≤0.3, x+y+z=1, and Me is Mn or Al.

Assignees

• Samsung Sdi Co Ltd

Inventors

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

Classifications

• H01M10/0568

  characterised by the solutes · CPC title

• H01M4/505

  of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M2300/0025

  Organic electrolyte · CPC title

• 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