Separator and lithium battery including the same

Patent metadata

Field	Value
Publication number	US-2021320378-A1
Application number	US-202117226999-A
Country	US
Kind code	A1
Filing date	Apr 9, 2021
Priority date	Apr 13, 2020
Publication date	Oct 14, 2021
Grant date	—

Abstract

This application relates to a separator and a lithium battery employing the same. In one aspect, the separator includes a porous substrate and a coating layer disposed on a surface of the porous substrate. The coating layer includes organic particles, a first binder, and inorganic particles. The organic particles have a first melting point of about 100° C. to about 130° C. The first binder has a second melting point higher than the first melting point by about 30° C. or more. The organic particles are coated by or embedded in the first binder. The separator can maintain a network structure even at a high temperature, making it possible to improve the high-temperature stability of a lithium battery by employing the separator, as well as delaying a rapid increase in temperature and heat generation when a shutdown occurs.

First claim

What is claimed is:

1 . A separator for a lithium battery, the separator comprising:
a porous substrate; and a coating layer disposed on a surface of the porous substrate, the coating layer comprising organic particles, a first binder and inorganic particles, the organic particles having a first melting point of about 100° C. to about 130° C., the first binder having a second melting point higher than the first melting point by about 30° C. or more.

2 . The separator of claim 1 , wherein the second melting point is about 160° C. or higher.

3 . The separator of claim 1 , wherein the second melting point is about 160° C. to about 180° C.

4 . The separator of claim 1 , wherein the organic particles are coated by the first binder.

5 . The separator of claim 1 , wherein the organic particles are embedded in the first binder.

6 . The separator of claim 1 , wherein the first binder has a matrix form of a network structure.

7 . The separator of claim 1 , wherein the organic particles comprise at least one selected from the group consisting of polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinylidene fluoride (PVDF), polymethyl methacrylate (PMMA), an acrylate compound, polyacrylonitrile (PAN), an azodicarbonamide compound, derivatives thereof, and copolymers thereof.

8 . The separator of claim 1 , wherein the first binder comprises at least one selected from the group consisting of a sulfonate compound and a derivative thereof, an acrylamide compound and a derivative thereof, an acrylonitrile compound and a derivative thereof, copolymers thereof, and mixtures thereof.

9 . The separator of claim 1 , wherein a content of the first binder is in a range of about 1 wt % to about 15 wt % based on a total weight of the organic particles and the first binder.

10 . The separator of claim 1 , wherein a content of the organic particles is in a range of more than about 50 wt % based on a total weight of the organic particles and the inorganic particles.

11 . The separator of claim 10 , wherein a weight ratio of the organic particles and the inorganic particles is about 51:49 to about 90:10.

12 . The separator of claim 1 , wherein the inorganic particles comprise at least one selected from the group consisting of alumina (Al 2 O 3 ), boehmite, BaSO4, MgO, Mg(OH) 2 , clay, silica (SiO 2 ), and TiO 2 .

13 . The separator of claim 1 , wherein the coating layer has a thickness of about 0.1 μm to about 5.0 μm.

14 . The separator of claim 1 , further comprising: an electrode adhesive layer on the coating layer.

15 . The separator of claim 14 , wherein the electrode adhesive layer has a thickness of about 0.1 μm to about 5.0 μm.

16 . A lithium battery comprising:
an electrode assembly comprising:
a cathode;
an anode; and
a separator interposed between the cathode and the anode, the separator comprising:
a porous substrate; and
a coating layer disposed on a surface of the porous substrate, the coating layer comprising organic particles, a first binder and inorganic particles, the organic particles having a first melting point of about 100° C. to about 130° C., the first binder having a second melting point higher than the first melting point by about 30° C. or more.

17 . The lithium battery of claim 16 , wherein the electrode assembly is wound in a jelly roll shape.

18 . A separator for a lithium battery, the separator comprising:
a porous substrate; and a coating layer disposed on a surface of the porous substrate, the coating layer comprising organic particles, a first binder and inorganic particles, the organic particles having a first melting point, the first binder having a second melting point higher than the first melting point, wherein the organic particles are coated with or embedded in the first binder.

19 . The separator of claim 18 , wherein the second melting point is higher than the first melting point by about 30° C. or more.

20 . The separator of claim 19 , wherein the first melting point is about 100° C. to about 130° C. and the second melting point is about 160° C. to about 180° C.

Assignees

• Samsung Sdi Co Ltd

Inventors

• Lee Jungyoon
• Choi Hyeonsun
• Kim Yangseob
• Kim Jinyoung

Classifications

• H01M10/052 Primary

  Li-accumulators · CPC title

• H01M10/4235

  Safety or regulating additives or arrangements in electrodes, separators or electrolyte (H01M10/4242 takes precedence) · CPC title

• Y02P70/50

  Manufacturing or production processes characterised by the final manufactured product · CPC title

• H01M10/0587

  of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title