Electrolyte for rechargeable lithium battery and rechargeable lithium battery including the same

Patent metadata

Field	Value
Publication number	US-9620818-B2
Application number	US-201514602152-A
Country	US
Kind code	B2
Filing date	Jan 21, 2015
Priority date	Apr 9, 2014
Publication date	Apr 11, 2017
Grant date	Apr 11, 2017

Abstract

An electrolyte for a rechargeable lithium battery includes a lithium salt, an organic solvent and an additive. The organic solvent includes a sulfur-containing compound represented by Chemical Formula 1, and the additive includes a phosphazene compound represented by Chemical Formula 2. A rechargeable lithium battery including the electrolyte may have improved performance and safety.

In Chemical Formulae 1 and 2, the substituents are as defined in the detailed description.

First claim

What is claimed is:

1. An electrolyte for a rechargeable lithium battery comprising:
a lithium salt;
an organic solvent comprising a sulfur containing compound represented by Chemical Formula 1, the sulfur containing compound in an amount of about 0.1% to about 20% by volume based on total amount of the organic solvent, and
an additive comprising a phosphazene compound represented by one selected from Chemical Formulae 3 and 4, the phosphazene compound being in an amount of about 3 to about 15 parts by weight based on 100 parts by weight of the organic solvent:

wherein
R 1 to R 8 are each independently hydrogen,

2. The electrolyte of claim 1 , wherein the sulfur-containing compound is in an amount of about 0.1% to about 10% by volume based on the total amount of the organic solvent.

3. The electrolyte for a rechargeable lithium battery of claim 1 , wherein the organic solvent further comprises a carbonate-based compound selected from diethyl carbonate (DEC), dipropyl carbonate (DPC), methylpropyl carbonate (MPC), ethylpropyl carbonate (EPC), ethylmethyl carbonate (EMC), ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), and a combination thereof.

4. The electrolyte for a rechargeable lithium battery of claim 1 , wherein the additive further comprises fluoroethylene carbonate, vinylethylene carbonate, propane sultone, succinonitrile, adiponitrile, LiBF 4 , or a combination thereof.

5. The electrolyte for a rechargeable lithium battery of claim 1 , wherein the electrolyte has a viscosity of less than or equal to about 7 cP.

6. The electrolyte for a rechargeable lithium battery of claim 1 , wherein the electrolyte has an ion conductivity of greater than or equal to about 5 mS/cm.

7. A rechargeable lithium battery comprising:
a positive electrode;
a negative electrode;
a separator; and
the electrolyte of claim 1 .

Assignees

• Samsung Sdi Co Ltd

Inventors

• Han Sang-Il
• Kim Duck-Hyun
• Park Young Sam
• Kim Moon-Sung
• Shin Woo-Cheol
• Kim Bong-Chull
• Lee Jeong-Hye
• Cho E-Rang
• Lee Min-Young
• Yang Ho-Seok
• Kim Byung-Hwa
• Park Young-Hwan

Classifications

• H01M2300/0037

  Mixture of solvents · CPC title

• H01M10/0568

  characterised by the solutes · CPC title

• H01M2300/0034

  Fluorinated solvents · CPC title

• H01M10/0569

  characterised by the solvents · CPC title

• H01M10/052

  Li-accumulators · CPC title