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

Patent metadata

Field	Value
Publication number	US-10964977-B2
Application number	US-201715684260-A
Country	US
Kind code	B2
Filing date	Aug 23, 2017
Priority date	Dec 26, 2016
Publication date	Mar 30, 2021
Grant date	Mar 30, 2021

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 method of manufacturing a separator for a secondary battery, comprising:
(a) impregnating of a porous non-woven fabric material with a baroplastic polymer powder by filtration;
(b) coating surfaces of porous non-woven fabric material impregnated with the baroplastic polymer powder using a binder solution;
(c) drying the binder solution-coated on the porous non-woven fabric material; and
(d) laminating a positive electrode and a negative electrode on the dried porous non-woven fabric material to form an assembly and pressing the assembly,
wherein the baroplastic polymer powder is molded by pressing, and
wherein pores in the porous non-woven fabric material are filled with the baroplastic polymer by molding the baroplastic polymer powder,
wherein the pressing is carried out by hot-pressing at a temperature of about 20° C. to 100° C. and at a pressure of about 1 to 4 ton/in 2 ,
wherein the baroplastic polymer powder comprises block copolymer of polystyrene and polyisoprene,
wherein the baroplastic polymer powder has an average particle diameter of about 10 to 100 μm, and
wherein an amount of the baroplastic polymer powder is 15% by volume to 60% by volume based on the volume of the porous non-woven fabric material.

2. The method 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.

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

4. The method according to claim 1 , wherein the binder solution is prepared by dissolving at least one binder selected from the group consisting of polyvinylidene fluoride (PVdF), polyester and polyacrylonitrile in N-methyl-2-pyrrolidone (NMP) or N,N-dimethylacetamide (DMAc).

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

• H01M50/443

  Particulate material · CPC title

• H01M50/491

  Porosity · CPC title

• H01M50/414

  Synthetic resins, e.g. thermoplastics or thermosetting resins · CPC title

• H01M50/403 Primary

  Manufacturing processes of separators, membranes or diaphragms · CPC title

• Y02P70/50

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