Method for producing positive electrode for secondary battery

Patent metadata

Field	Value
Publication number	US-2018323423-A1
Application number	US-201815968900-A
Country	US
Kind code	A1
Filing date	May 2, 2018
Priority date	May 2, 2017
Publication date	Nov 8, 2018
Grant date	—

Abstract

The present disclosure relates to a method for producing a positive electrode for a secondary battery, the method including applying a composition for forming a positive electrode on a positive electrode current collector to form a positive electrode mixture layer, and rolling the positive electrode mixture layer such that the elongation of the positive electrode current collector is less than 1%, to produce a positive electrode.

First claim

What is claimed is:

1 . A method for producing a positive electrode for a secondary battery, the method comprising:
applying a composition for forming the positive electrode on a positive electrode current collector to form a positive electrode mixture layer; and rolling the positive electrode mixture layer such that the elongation of the positive electrode current collector is less than 1%, to produce the positive electrode.

2 . The method of claim 1 , wherein the rolling is performed two times or less.

3 . The method of claim 1 , wherein after the rolling, the porosity of the positive electrode mixture layer is 25% or less.

4 . The method of claim 1 , wherein the rolling is performed at a pressure of 3 to 5 kgf.

5 . The method of claim 1 , wherein the positive electrode current collector before the rolling has an area of 1.4875 cm 2 and a weight per 20 μm thickness of 8.0 to 9.0 mg.

6 . The method of claim 1 , wherein the composition for forming a positive electrode comprises a positive active material, a conductive material, and a binder,
wherein the positive electrode active material has an average particle diameter (D 50 ) of 5 to 15 μm.

7 . The method of claim 1 , wherein the composition for forming the positive electrode comprises a positive active material, a conductive material, and a binder,
wherein the positive electrode active material comprises large-diameter particles having an average particle diameter (D 50 ) of 15 to 25 μm and small-diameter particles having an average particle diameter (D 50 ) of 3 to 6 μm.

8 . The method of claim 7 , wherein the large-diameter particles and the small-diameter particles are mixed at a weight ratio of 9:1 to 7:3.

9 . The method of claim 1 , wherein the positive electrode current collector is at least one selected from the group consisting of nickel, titanium, sintered carbon, and stainless steel.

10 . The method of claim 1 , wherein the composition for forming the positive electrode comprises a positive electrode active material, a conductive material and a binder,
wherein the positive electrode active material is a lithium transition metal oxide comprising at least one selected from the group consisting of nickel (Ni), cobalt (Co), and manganese (Mn).

Assignees

• Lg Chemical Ltd

Inventors

• Kim Ji Hye
• Jung Wang Mo
• Park Byung Chun
• Ryu Ji Hoon
• Han Jung Min

Classifications

• H01M4/505

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

• H01M4/1391

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

• H01M4/625

  Carbon or graphite · CPC title

• H01M10/0525

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

• H01M2004/028

  Positive electrodes · CPC title