Electrolyte additive and lithium secondary battery comprising the same

Patent metadata

Field	Value
Publication number	US-10770749-B2
Application number	US-201816170048-A
Country	US
Kind code	B2
Filing date	Oct 25, 2018
Priority date	Nov 2, 2017
Publication date	Sep 8, 2020
Grant date	Sep 8, 2020

Abstract

Provided is an electrolyte additive including a salt of an anion represented by Chemical Formula 1 below, with Cs + or Rb + :

wherein A is O or S, and R 1 and R 2 are each independently a C 1 -C 10 alkyl group in which all or some of the hydrogen atoms are substituted with halogen atoms.

First claim

What is claimed is:

1. A non-aqueous electrolyte comprising:
a lithium salt;
a non-aqueous organic solvent; and
an electrolyte additive comprising:
a salt of an anion represented by Chemical Formula 1 below with Cs + or Rb + :

wherein A is O or S, and R 1 and R 2 are each independently a C 1 -C 10 alkyl group in which all or some of the hydrogen atoms are substituted with halogen atoms.

2. The non-aqueous electrolyte of claim 1 , wherein the content of the electrolyte additive is 0.05 to 10 wt % based on the total amount of the non-aqueous electrolyte.

3. The non-aqueous electrolyte of claim 1 , wherein the lithium salt includes at least one selected from the group consisting of LiPF 6 , LiAsF 6 , LiCF 3 SO 3 , LiN(CF 3 SO 2 ) 2 , LiBF 6 , LiSbF 6 , LiAlO 4 , LiAlCl 4 , and LiClO 4 .

4. The non-aqueous electrolyte of claim 1 , wherein the lithium salt includes LiPF 6 .

5. The non-aqueous electrolyte of claim 1 , wherein the non-aqueous organic solvent includes at least one selected from the group consisting of an ether, an ester, an amide, a linear carbonate, a cyclic carbonate, a phosphate-based compound, a nitrile-based compound, a fluorinated ether-based compound, and a fluorinated aromatic compound.

6. A lithium secondary battery comprising:
a cathode including a cathode active material;
an anode including an anode active material;
a separator interposed between the cathode and the anode; and
the non-aqueous electrolyte of claim 1 .

7. The lithium secondary battery of claim 6 , wherein the cathode active material includes at least one selected from the group consisting of compounds represented by Chemical Formulas 6 to 8 below:
Li[Ni a Co b Mn c ]O 2   [Chemical Formula 6]

(0.1 ≤c≤0.5, 0<a+b<0.9, a+b+c=1);
LiMn 2-x M x O 4   [Chemical Formula 7]

(M is one or more elements selected from the group consisting of Ni, Co, Fe, P, S, Zr, Ti and Al, 0 <x≤2);
Li 1+a Co x M 1-x BX 4   [Chemical Formula 8]

(M is one or more elements selected from the group consisting of Al, Mg, Ni, Co, Mn, Ti, Ga, Cu, V, Nb, Zr, Ce, In, Zn, and Y, X is one or more elements selected from the group consisting of O, F, and N, B is P, S or a mixed element thereof, 0 ≤a≤0.2, and 0.5≤x≤1).

8. The lithium secondary battery of claim 6 , wherein the cathode active material includes at least one selected from the group consisting of Li[Ni 0.6 Co 0.2 Mn 0.2 ]O 2 , Li(Ni 0.5 Co 0.2 Mn 0.3 )O 2 , Li[Ni 1/3 Co 1/3 Mn 1/3 ]O 2 , and LiCoO 2 .

9. The non-aqueous electrolyte of claim 1 , wherein the anion represented by Chemical Formula 1 is one or more selected from the group consisting of anions represented by Chemical Formulas 2 to 5 below:

10. The non-aqueous electrolyte of claim 9 , wherein the anion represented by Chemical Formula 1 is an anion represented by Chemical Formula 2 below:

11. The non-aqueous electrolyte of claim 1 , further comprising:
at least one salt selected from the group consisting of CsCF 3 SO 3 , CsPO 2 F 2 , CsPF 2 (C 2 O 4 ) 2 and CsB(C 2 O 4 ) 2 .

Assignees

• Soulbrain Co Ltd

Inventors

• Kim Jae Yoon
• Kim Min Goo
• Lee Jong Hyun
• Han Ji Seong

Classifications

• H01M4/505

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

• H01M10/0567 Primary

  characterised by the additives · CPC title

• H01M2300/0028

  characterised by the solvent · CPC title