Method of mixing cathode active material

Patent metadata

Field	Value
Publication number	US-11769880-B2
Application number	US-202117460036-A
Country	US
Kind code	B2
Filing date	Aug 27, 2021
Priority date	Nov 12, 2020
Publication date	Sep 26, 2023
Grant date	Sep 26, 2023

Abstract

A method of mixing a cathode active material in a process of manufacturing a cathode of a lithium secondary battery is provided. The method includes a preparation step of preparing a lithium compound removal solution in which PAA (polyacrylic acid) is mixed with a solvent, a removal step of reacting the lithium compound removal solution with the cathode active material, on a surface of which a lithium compound is present, thus removing the lithium compound present on the surface of the cathode active material, and a mixing step of mixing the cathode active material, which is mixed with the lithium compound removal solution, with a conductive material and a binder.

First claim

What is claimed is:

1. A method of mixing a cathode active material in a process of manufacturing a cathode of a lithium secondary battery, comprising:
a preparation step of preparing a lithium compound removal solution in which PAA (polyacrylic acid) is mixed with a solvent, wherein in the preparation step, the lithium compound is LiOH;
a removal step of reacting the lithium compound removal solution with the cathode active material, on a surface of which the lithium compound is present, thus removing the lithium compound present on the surface of the cathode active material;
a mixing step of mixing the cathode active material, which is mixed with the lithium compound removal solution, with a conductive material and a binder; and
between the removal step and the mixing step, a reaction maintenance step of maintaining a reaction for 20 minutes or more so that the LiOH present in the cathode active material is reacted with the PAA to generate Li-PAA.

2. The method of claim 1 , further comprising: a drying step of drying the solvent between the reaction maintenance step and the mixing step in order to remove H 2 O generated in the reaction of LiOH with the PAA in the removal step.

3. The method of claim 1 , wherein the solvent includes one or more of CH 3 OH, CH 3 CH 2 OH, CH 3 CH(OH)CH 3 , H 2 O, NMP, DMSO, DMF, hexane, or THF.

4. The method of claim 1 , wherein an average molecular weight of the PAA used in the removal step is 100,000 to 4,000,000.

5. The method of claim 1 , wherein in the removal step, a content of the LiOH present on the surface of the cathode active material mixed with the lithium compound removal solution is 0.05 to 1.5 wt % of a mass of the cathode active material.

6. The method of claim 1 , wherein in the preparation step, a content of the PAA is 20 to 300 wt % of a mass of the LiOH in the cathode active material.

7. A lithium secondary battery comprising:
a cathode including a cathode active material manufactured using the method of mixing the cathode active material according to claim 1 ;
an anode;
a separation membrane interposed between the cathode and the anode; and
an electrolytic solution.

Assignees

• Hyundai Motor Co Ltd
• Kia Corp

Inventors

• Park Sang Mok
• Oh Seung Min
• Jin Woo Young
• Lee Ji Eun
• Lee Sang Hun
• Kim Ko Eun
• Rhee Jun Ki
• Lee Yoon Sung

Classifications

• H01M4/60 Primary

  of organic compounds · CPC title

• H01M4/0471

  involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis · CPC title

• H01M4/364

  as mixtures · CPC title

• H01M4/621

  Binders · CPC title

• H01M4/624

  Electric conductive fillers · CPC title