Separator for electrochemical device, and electrochemical device

Patent metadata

Field	Value
Publication number	US-11050095-B2
Application number	US-66692105-A
Country	US
Kind code	B2
Filing date	Dec 8, 2005
Priority date	Dec 8, 2004
Publication date	Jun 29, 2021
Grant date	Jun 29, 2021

Abstract

An electrochemical device having excellent safety at high temperature is provided by using a separator for an electrochemical device, which is made of a porous film comprising: a porous base ( 5 ) having a heat-resistant temperature of 150° C. or higher and including filler particles ( 3 ); at least one kind of shutdown resin ( 6 ) selected from the group consisting of resin A that has a melting point in a range of 80° C. to 130° C. and resin B that absorbs an electrolyte and swells due to heating, and the swelling degree is increased as the temperature rises; and a binder ( 4 ).

First claim

The invention claimed is:

1. A separator for an electrochemical device, comprising a porous film comprising a porous base and a shutdown resin, wherein
the porous base comprises a coating film and has a heat-resistant temperature of not lower than 150° C., the coating film being formed by integrating a number of filler particles with a binder,
wherein the filler particles include plate-like boehmite particles,
a content of the binder in the coating film is 2.4 to 4.8 mass %, and
the filler particles and the shutdown resin are separately distributed unevenly in the form of a layer parallel to a film face of the separator.

2. The separator for an electrochemical device according to claim 1 , wherein the porous base has a thickness of not more than 20 μm.

3. The separator for an electrochemical device according to claim 1 , wherein plate-shape surfaces of the plate-like boehmite particles are oriented to be parallel to a film surface of the porous base.

4. The separator for an electrochemical device according to claim 1 , wherein the filler particles include particles having an aspect ratio in a range of 2 to 10 as the plate-like boehmite particles.

5. A separator for an electrochemical device, comprising a porous film comprising a porous base and a resin, wherein
the porous base comprises a coating film and has a heat-resistant temperature of not lower than 150° C., the coating film being formed by integrating a number of filler particles with a binder,
the filler particles include plate-like boehmite particles,
the resin includes at least one shutdown resin selected from the group consisting of resin A that has a melting point in a range of 80° C. to 130° C., and resin B that absorbs an electrolyte and swells due to heating, and the swelling degree is increased as the temperature rises,
a percentage of the porous base is not less than 10 vol. % and not more than 90 vol. % of whole ingredients of the separator, the separator for an electrochemical device has a thickness of not more than 30 μm, and
the filler particles and the shutdown resin are separately distributed unevenly in the form of a layer parallel to a film face of the separator.

6. The separator for an electrochemical device according to claim 5 , wherein air permeability expressed as a Gurley value is in a range of 10 to 300 (sec/100 L).

7. The separator for an electrochemical device according to claim 5 , wherein the content of the shutdown resin is not less than 45.2 vol. % and not more than 80 vol. % of whole ingredients of the separator.

8. The separator for an electrochemical device according to claim 5 , wherein the separator has a porosity of 20% or more and 70% or less.

9. The separator for an electrochemical device according to claim 5 , wherein a content of the binder in the coating film of the porous base is 2.4 to 4.8 mass %.

10. An electrochemical device comprising a positive electrode, a negative electrode, a nonaqueous electrolyte and a separator,
wherein the separator is the separator for an electrochemical device according to claim 5 .

11. The electrochemical device according to claim 10 , wherein the separator is integrated with the positive electrode or the negative electrode.

Assignees

• Katayama Hideaki
• Abe Toshihiro
• Matsumoto Nobuaki
• Kita Fusaji
• Aoyama Shigeo
• Maxell Holdings Ltd

Inventors

• Katayama Hideaki
• Abe Toshihiro
• Matsumoto Nobuaki
• Kita Fusaji
• Aoyama Shigeo

Classifications

• H01M50/434

  Ceramics · CPC title

• H01M50/489

  Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties · CPC title

• H01M50/429

  Natural polymers · CPC title

• H01M50/414

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

• H01M50/44

  Fibrous material · CPC title