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

Patent metadata

Field	Value
Publication number	US-11843091-B2
Application number	US-201916558503-A
Country	US
Kind code	B2
Filing date	Sep 3, 2019
Priority date	Sep 3, 2018
Publication date	Dec 12, 2023
Grant date	Dec 12, 2023

Abstract

A separator for a rechargeable lithium battery and a rechargeable lithium battery including the separator, the separator including a porous substrate; and a coating layer on at least one surface of the porous substrate, wherein the coating layer includes organic filler particles, fluorine organic binder particles, and (meth)acryl organic binder particles, an average particle diameter of the organic filler particles is equal to or greater than an average particle diameter of the fluorine organic binder particles, and the fluorine organic binder particles are coated on the porous substrate as a part of the coating layer in an amount of less than about 0.1 g/m 2 per surface.

First claim

What is claimed is:

1. A separator for a rechargeable lithium battery, the separator comprising:
a porous substrate; and
a coating layer on at least one surface of the porous substrate,
wherein:
the coating layer includes organic filler particles, fluorine organic binder particles, and (meth)acryl organic binder particles, the organic filler particles being different from the (meth)acryl organic binder particles,
an average particle diameter of the organic filler particles is equal to or greater than an average particle diameter of the fluorine organic binder particles,
the fluorine organic binder particles are coated on the porous substrate as a part of the coating layer in an amount of 0.030 g/m 2 to 0.1 g/m 2 per surface,
the average particle diameter of the organic filler particles is about 0.15 μm to about 3 μm,
the organic filler particles and the fluorine organic binder are included in a weight ratio of 50:50 to 90:10 and
a ratio of the average particle diameter of the organic filler particles and the average particle diameter of the fluorine organic binder particles is about 1:1 to about 2:1.

2. The separator as claimed in claim 1 , wherein the organic filler particles include a (meth)acrylate compound, a diallyl phthalate compound, polyimide compound, polyurethane compound, a copolymer thereof, or a combination thereof.

3. The separator as claimed in claim 1 , wherein the organic filler particles include a cross-linked polymer.

4. The separator as claimed in claim 1 , wherein the average particle diameter of the organic filler particles is about 0.2 μm to about 0.5 μm.

5. The separator as claimed in claim 1 , wherein the fluorine organic binder particles include:
a homopolymer of a vinylidene fluoride monomer, or
a copolymer of a vinylidene fluoride monomer and another monomer.

6. The separator as claimed in claim 1 , wherein the average particle diameter of the fluorine organic binder particles is about 100 nm to about 400 nm.

7. The separator as claimed in claim 1 , wherein the fluorine organic binder particles include a polyvinylidene fluoride-hexafluoropropylene (PVdF-HFP) copolymer and includes about 1 mol % to about 12 mol % of a hexafluoropropylene repeating unit.

8. The separator as claimed in claim 1 , wherein the (meth)acryl organic binder particles include a repeating unit of a (meth)acrylate or a (meth)acrylic acid.

9. A rechargeable lithium battery, comprising:
a positive electrode,
a negative electrode, and
the separator as claimed in claim 1 between the positive electrode and the negative electrode.

10. The separator as claimed in claim 1 , wherein the average particle diameter of the organic filler particles is greater than the average particle diameter of the fluorine organic binder particles.

Assignees

• Samsung Sdi Co Ltd

Inventors

• Kim Gain
• Kim Yongkyoung
• Kim Yangseob
• Lee Jungyoon

Classifications

• H01M10/0525 Primary

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

• H01M50/42

  Acrylic resins · CPC title

• H01M50/426

  Fluorocarbon polymers · CPC title

• H01M50/449

  having a layered structure · CPC title

• H01M50/457

  comprising three or more layers · CPC title