Method for manufacturing electrode for secondary battery and method for manufacturing secondary battery

Patent metadata

Field	Value
Publication number	US-11469405-B2
Application number	US-201816766358-A
Country	US
Kind code	B2
Filing date	Nov 13, 2018
Priority date	Nov 24, 2017
Publication date	Oct 11, 2022
Grant date	Oct 11, 2022

Abstract

A method for manufacturing an electrode for a secondary battery includes: applying a first layer slurry containing a first binder to a surface of a current collector, applying a second layer slurry containing a second binder on the first layer slurry before the first layer slurry is dried, and drying the first layer slurry and the second layer slurry after applying the first layer slurry and the second layer slurry to obtain a laminated structure in which a first layer and a second layer are laminated in this order on the current collector. The second layer slurry has a solid content ratio of more than 50% by mass and a composition ratio of the second binder of more than 2% by mass.

First claim

The invention claimed is:

1. A method for manufacturing an electrode used as a positive electrode and a negative electrode of a secondary battery comprising:
applying a first layer slurry containing a first binder to a surface of a current collector,
applying a second layer slurry containing a second binder on the first layer slurry before the first layer slurry is dried, and
drying the first layer slurry and the second layer slurry after applying the first layer slurry and the second layer slurry to obtain a laminated structure in which a first layer and a second layer are laminated in this order on the current collector,
wherein the second layer slurry has a solid content ratio of more than 50% by mass and a composition ratio of the second binder of more than 2% by mass, and
wherein the first layer slurry is an active material layer slurry, the second layer slurry is an insulating layer slurry, the first layer is an active material layer, and the second layer is an insulating layer.

2. The method for manufacturing the electrode for the secondary battery according to claim 1 , wherein the second layer slurry has the solid content ratio of 59% by mass or more.

3. The method for manufacturing the electrode for the secondary battery according to claim 1 , wherein a viscosity of the first layer slurry is 12000 mPa·s or more, and/or a viscosity of the second layer slurry is 4000 mPa·s or more when the viscosities of the first layer slurry and the second layer slurry are measured at 25° C. with a shear rate of 1/sec.

4. The method for manufacturing the electrode for the secondary battery according to claim 1 , wherein the viscosity of the second layer slurry is 4000 mPa·s or more and the viscosity of the first layer slurry is 5000 mPa·s or more.

5. The method for manufacturing the electrode for the secondary battery according to claim 3 , wherein the viscosity of the first layer slurry and the second layer slurry is 50000 mPa·s or more and 200000 mPa·s or less.

6. The method for manufacturing the electrode for the secondary battery according to claim 1 , wherein a viscosity of the first layer slurry and/or the second layer slurry measured at 25° C. with a shear rate of 5/sec is less than half of the viscosity measured at 25° C. with the shear rate of 1/sec.

7. The method for manufacturing the electrode for the secondary battery according to claim 1 , wherein the first layer slurry includes an active material, a binder and a solvent, and the second layer slurry includes a main material, non-conductive particles, a binder and a solvent.

8. The method for manufacturing the electrode for the secondary battery according to claim 7 , wherein the first layer slurry and the second layer slurry have same main component of the binder.

9. The method for manufacturing the electrode for the secondary battery according to claim 7 , wherein the first layer slurry and the second layer slurry have same main component of the solvent.

10. The method for manufacturing the electrode for the secondary battery according to claim 1 , further comprising:
cooling at least a surface of the first layer slurry after applying the first layer slurry and before applying the second layer slurry.

11. The method for manufacturing the electrode for the secondary battery according to claim 1 , wherein in the step of obtaining the laminated structure, a time from completion of applying of the second layer slurry to start of drying of the first layer slurry and the second layer slurry is within 10 seconds.

12. A method for manufacturing a second battery comprising:
manufacturing a positive electrode and a negative electrode by the method for manufacturing according to claim 1 ,
arranging the positive electrode and the negative electrode facing each other to configure a battery element, and
enclosing the battery element together with an electrolytic solution in a casing.

Assignees

• Nec Corp

Inventors

• Yoshida Noboru
• Otohata Makihiro

Classifications

• H01M4/131

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

• H01M4/0404 Primary

  by coating on electrode collectors · CPC title

• H01M10/0566

  Liquid materials · CPC title

• H01M4/139

  Processes of manufacture · CPC title

• H01M4/505

  of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy · CPC title