Separator for secondary batteries with enhanced stability and method of manufacturing the same

Patent metadata

Field	Value
Publication number	US-11855261-B2
Application number	US-202117192009-A
Country	US
Kind code	B2
Filing date	Mar 4, 2021
Priority date	Dec 26, 2016
Publication date	Dec 26, 2023
Grant date	Dec 26, 2023

Abstract

Disclosed are a separator for secondary batteries with enhanced stability and a method of manufacturing the separator. The separator can prevent self-discharge which may occur when a porous non-woven fabric material is used for a separator; can perform a shutdown function at a high temperature of 200° C. or less; and can avoid even under harsh conditions of high temperatures, deterioration in stability caused by internal short-circuit of positive and negative electrodes. In particular, the separator for secondary batteries of the present invention includes a porous non-woven fabric material impregnated with a baroplastic polymer powder and pores of the porous non-woven fabric material are filled with the baroplastic polymer powder by pressing an assembly of the secondary battery.

First claim

What is claimed is:

1. A separator for a secondary battery, comprising:
a porous non-woven fabric material; and

a baroplastic polymer powder impregnated in the porous non-woven fabric material,
wherein pores of the porous non-woven fabric material comprise the baroplastic polymer powder,
wherein the baroplastic polymer powder comprises block copolymer of polystyrene and polyisoprene,
wherein an amount of the baroplastic polymer powder is 15% by volume to 60% by volume based on volume of the porous non-woven fabric material.

2. The separator according to claim 1 , wherein the pores of the porous non-woven fabric material are filled with the baroplastic polymer powder.

3. The separator according to claim 1 , wherein the porous non-woven fabric material comprises one or more selected from the group consisting of polyolefin, polyimide, aramid, cellulose, polyacrylonitrile, polyester and polyamide.

4. The separator according to claim 1 , wherein the pores of the porous non-woven fabric material have a size of about 1 μm to 100 μm and the porous non-woven fabric material has porosity of about 20% to 70%.

5. The separator according to claim 1 , wherein the baroplastic polymer powder has an average particle diameter of about 10 to 100 μm.

6. The separator according to claim 1 , wherein the pores in the porous non-woven fabric material is filled with the baroplastic polymer powder by pressing the porous non-woven fabric material upon assembly of the secondary battery, and the pressing is carried out by hot-pressing at a temperature of about 20° C. to 100° C. and a pressure of about 1 to 4 tons.

7. The separator according to claim 1 , wherein the separator for the secondary battery further comprises a coating layer of a binder solution formed on surfaces of the porous non-woven fabric material filled with the baroplastic polymer powder.

8. The separator according to claim 7 , wherein the binder solution comprises i) at least one binder selected from the group consisting of polyvinylidene fluoride (PVdF), polyester and polyacrylonitrile; and ii) N-methyl-2-pyrrolidone (NMP) or N,N-dimethylacetamide (DMAc).

9. A secondary battery comprising a separator of claim 1 .

10. A vehicle that comprises a secondary battery of claim 9 .

Assignees

• Hyundai Motor Co Ltd
• Kia Motors Corp

Inventors

• Yeo Yeol Mae
• Koh Ki Seok
• Lee Yoon Sung
• Oh Seung Min
• Min Hong Seok
• Choi Sung Min

Classifications

• H01M10/0587 Primary

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

• C08J3/12

  Powdering or granulating · CPC title

• C08J3/18

  Plasticising macromolecular compounds (plasticisers C08K) · CPC title

• H01M10/0525

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

• H01M10/14

  Assembling a group of electrodes or separators · CPC title