Separator having porous coating layer, method for manufacturing the same and electrochemical device having the same

Patent metadata

Field	Value
Publication number	US-10916754-B2
Application number	US-201514840875-A
Country	US
Kind code	B2
Filing date	Aug 31, 2015
Priority date	Nov 29, 2007
Publication date	Feb 9, 2021
Grant date	Feb 9, 2021

Abstract

A separator includes a porous substrate having a plurality of pores; and a porous coating layer formed on at least one surface of the porous substrate and made of a mixture of a binder and a plurality of inorganic particles, wherein the binder includes a crosslinked binder. This separator may improve high temperature cycle performance, discharge characteristics and thermal resistance of an electrochemical device since the separator exhibits improved insolubility and impregnation to electrolyte and improved thermal resistance.

First claim

The invention claimed is:

1. A method for manufacturing a separator, comprising:
preparing a coating solution containing a crosslinkable binder component selected from the group consisting of a crosslinkable polymer, a crosslinkable molecule, and their mixtures, or containing a crosslinking agent and a crosslinkable binder component selected from the group consisting of polymer having at least two reactive groups, a molecule having at least two reactive groups, or their mixtures;
adding inorganic particles to the coating solution such that the inorganic particles are dispersed in the coating solution;
applying the coating solution in which the inorganic particles are dispersed to at least one surface of a porous substrate with a pore size of 0.01 to 50 μm and porosity of 10 to 95% to form a coating layer, wherein the porous substrate includes at least one of a polyolefin porous film and a non-woven fabric; and
crosslinking the crosslinkable binder component in the coating layer at a reduced pressure of 0.1 to 500 torr to remove condensates or byproducts during the crosslinking, wherein a porous coating layer is formed with a thickness of 0.01 to 20 μm, made of a mixture of a binder and a plurality of inorganic particles, wherein the binder includes a crosslinked binder,
wherein the crosslinked binder is formed by reaction among binders selected from the group consisting of a polymer having at least three reactive groups, a molecule having at least three reactive groups, and their mixtures, or the crosslinked binder is obtained by crosslinking a binder selected from the group consisting of a polymer having at least two reactive groups, a molecule having at least two reactive groups, and their mixtures by using a crosslinking agent,
wherein the crosslinking agent is a compound having at least three reactive groups,
wherein each of the reactive groups is selected from the group consisting of a vinyl group, an epoxy group, a hydroxyl group, an ester group, and a cyanate group,
wherein a weight ratio of the inorganic particles and the crosslinked binder is 50:50 to 99:1, and
wherein the crosslinked binder is selected from the group consisting of a crosslinked polymethylmethacrylate, a crosslinked polyvinylidenefluoride, a crosslinked polyvinylidenefluoride-hexafluoropropylene copolymer, a crosslinked polyester, a crosslinked polyurethane, a crosslinked polyurea, a crosslinked cellulose acetate and a crosslinked binder having at least two different crosslinked binders.

2. The method for manufacturing a separator according to claim 1 ,
wherein the solvent is comprised of one or more of acetone, tetrahydrofuran, methylene chloride, chloroform, dimethylformamide, N-methyl-2-pyrrolidone (NMP), cyclohexane, water, and their mixtures.

Assignees

• Lg Chemical Ltd
• Toray Industries

Inventors

• Kim Jong-Hun
• Lee Sang-Young
• Park Pil-Kyu
• Hong Jang-Hyuk
• Shin Byoung-Jin
• Kim In-Chul

Classifications

• H01M10/0525 Primary

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

• H01M50/454

  comprising a non-fibrous layer and a fibrous layer superimposed on one another · CPC title

• H01M50/417

  Polyolefins · CPC title

• H01M50/491 Primary

  Porosity · CPC title

• H01M50/414

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