Electrode with porous protective film, nonaqueous electrolyte secondary battery, and method for manufacturing electrode with porous protective film

Patent metadata

Field	Value
Publication number	US-10020478-B2
Application number	US-201514972458-A
Country	US
Kind code	B2
Filing date	Dec 17, 2015
Priority date	Jun 11, 2008
Publication date	Jul 10, 2018
Grant date	Jul 10, 2018

Abstract

An electrode with a porous protective film includes an electrode in which an active material layer is disposed on a collector and a porous protective film which is disposed on a surface of the active material layer and which contains fine particles and a binder. The thickness of the porous protective film ranges from about 0.1 μm to about 200 μm. A nonaqueous electrolyte secondary battery includes a negative electrode in which a negative electrode active material layer is disposed on a negative electrode collector, a positive electrode, a nonaqueous electrolyte, a separator, and a porous protective film which is disposed on at least one of a surface of the negative electrode active material layer or a surface of the positive electrode active material layer and which contains fine particles and a binder. The thickness of the porous protective film ranges from about 0.1 μm to about 200 μm.

First claim

The application is claimed as follows:

1. A battery comprising:
a negative electrode comprising a negative electrode active material layer provided on a negative electrode current collector;
a positive electrode comprising a positive electrode active material layer provided on a positive electrode current collector;
an electrolyte;
a separator; and
a porous protective film provided between the separator and at least one of the negative electrode active material layer and the positive electrode active material layer,
wherein the porous protective film comprises particles, a binder, and 10 to 100 parts by weight of a thickener relative to 100 parts by weight of the particles, and
wherein a thickness of the porous protective film ranges from about 0.1 μm to about 200 μm.

2. The battery according to claim 1 , wherein the thickener comprises at least one compound selected from the group consisting of hydroxyethyl cellulose, carboxymethyl cellulose, and polyethylene glycol.

3. The battery according to claim 1 , wherein a depth of penetration of a porous protective film-forming slurry into at least one of the negative electrode active material layer and the positive electrode active material layer is less than 4 μm.

4. The battery according to claim 1 , wherein the particles comprise a metal oxide.

5. The battery according to claim 4 , wherein the metal oxide comprises at least one compound selected from the group consisting of alumina, titania, zirconia, and silica.

6. The battery according to claim 1 , wherein the binder comprises at least one of a fluororesin and a rubber resin.

7. The battery according to claim 6 , wherein the rubber resin comprises at least one compound selected from the group consisting of styrene-butadiene rubber, acrylic rubber, and butadiene rubber.

8. The battery according to claim 1 , wherein an air permeability of the porous protective film ranges from about 3 sec/100 ml to about 600 sec/100 ml.

9. An electrode comprising:
an electrode including an active material layer provided on a current collector; and
a porous protective film provided on a surface of the active material layer, the porous protective film comprising particles, a binder, and 10 to 100 parts by weight of a thickener relative to 100 parts by weight of the particles, and
wherein a thickness of the porous protective film ranges from about 0.1 μm to about 200 μm.

10. The electrode according to claim 9 , wherein the thickener comprises at least one compound selected from the group consisting of hydroxyethyl cellulose, carboxymethyl cellulose, and polyethylene glycol.

11. The electrode according to claim 9 , wherein a depth of penetration of a porous protective film-forming slurry into the active material layer is less than 4 μm.

12. The electrode according to claim 9 , wherein the particles comprise a metal oxide.

13. The electrode according to claim 12 , wherein the metal oxide comprises at least one compound selected from the group consisting of alumina, titania, zirconia, and silica.

14. The electrode according to claim 9 , wherein the binder comprises at least one of a fluororesin and a rubber resin.

15. The electrode according to claim 14 , wherein the rubber resin comprises at least one compound selected from the group consisting of styrene-butadiene rubber, acrylic rubber, and butadiene rubber.

16. The electrode according to claim 9 , wherein an air permeability of the porous protective film ranges from about 3 sec/100 ml to about 600 sec/100 ml.

17. The battery according to claim 6 , wherein a mass ratio of the fluororesin to the rubber resin ranges from 1:9 to 9:1.

18. The battery according to claim 1 , wherein the diameter of the particles ranges from 0.1 to 1.0 μm.

Assignees

• Sony Corp
• Murata Manufacturing Co

Inventors

• Tadano Junichi

Classifications

• H01M2/1673 Primary

  Electricity · mapped topic

• H01M4/139

  Processes of manufacture · CPC title

• H01M4/131

  Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title

• H01M4/62

  Selection of inactive substances as ingredients for active masses, e.g. binders, fillers · CPC title

• Y02P70/54

  Cross-Sectional Technologies · mapped topic