Master Batch Comprising Positive Electrode Active Material and Irreversible Additive, and Positive Electrode Slurry, for Lithium Secondary Battery, Containing Same

Patent metadata

Field	Value
Publication number	US-2023335742-A1
Application number	US-202218026863-A
Country	US
Kind code	A1
Filing date	May 6, 2022
Priority date	May 31, 2021
Publication date	Oct 19, 2023
Grant date	—

Abstract

A master batch for a positive electrode additive and a positive electrode slurry for a lithium secondary battery that contains the same, wherein the master batch contains a high content of irreversible additive together with a positive electrode active material so that a small amount of irreversible additive is dispersed in the positive electrode slurry with high dispersion without loss when a positive electrode is manufactured, and thus a positive electrode for a lithium secondary battery manufactured using the irreversible additive has high electrical properties and reliability, and a degree of freedom in design is improved when the positive electrode is manufactured.

First claim

1 . A master batch for a positive electrode additive, comprising 0.5 to 50 parts by weight of a lithium cobalt oxide represented by Chemical Formula 1 with respect to 100 parts by weight of a first positive electrode active material:
Li p Co 1-q M 1 q O 4   [Chemical Formula 1]
in Chemical Formula 1, M 1 denotes one or more elements selected from the group consisting of W, Cu, Fe, V, Cr, Ti, Zr, Zn, Al, In, Ta, Y, La, Sr, Ga, Sc, Gd, Sm, Ca, Ce, Nb, Mg, B, and Mo, wherein p and q are 5≤p≤7 and 0≤q≤0.4.

2 . The master batch of claim 1 , wherein the master batch further includes 1 to 10 parts by weight of a first binder with respect to 100 parts by weight of the first positive electrode active material.

3 . The master batch of claim 1 , wherein an average particle size (D 50 ) of the master batch for the positive electrode additive ranges from 0.05 mm to 10 mm.

4 . The master batch of claim 1 , wherein:
an average particle size (D 50 ) of the first positive electrode active material ranges from 0.5 to 100 μm; and an average particle size (D 50 ) of the lithium cobalt oxide ranges from 1 to 200 μm, wherein the average particle size of the lithium cobalt oxide is greater than the average particle size of the first positive electrode active material.

5 . A positive electrode slurry for a lithium secondary battery, comprising:
the master batch for a positive electrode additive according to claim 1 ; a second positive electrode active material; a conductive material; and a second binder.

6 . The positive electrode slurry of claim 5 , wherein the lithium cobalt oxide of Chemical Formula 1 contained in the master batch is included in an amount of 0.05 to 2.0 parts by weight with respect to 100 parts by weight of a total amount of the positive electrode slurry.

7 . The positive electrode slurry of claim 5 , wherein the master batch for the positive electrode additive is included in an amount of 1 to 150 parts by weight with respect to 100 parts by weight of the second positive electrode active material.

8 . The positive electrode slurry of claim 5 , wherein each of the first positive electrode active material and the second positive electrode active material includes a lithium metal composite oxide represented by Chemical Formula 2:
Li x [Ni y Co z Mn w M 2 v ]O u   [Chemical Formula 2]
in Chemical Formula 2, M 2 denotes one or more elements selected from the group consisting of W, Cu, Fe, V, Cr, Ti, Zr, Zn, Al, In, Ta, Y, La, Sr, Ga, Sc, Gd, Sm, Ca, Ce, Nb, Mg, B, and Mo, wherein x, y, z, w, v, and u are 1.0≤x≤1.30, 0.1≤y<1, 0.01<z≤0.6, 0.01<w≤0.6, 0≤v≤0.2, and 1.5≤u≤5.

9 . The positive electrode slurry of claim 5 , wherein the conductive material is included in an amount of 1 to 5 parts by weight with respect to 100 parts by weight of a total amount of the positive electrode slurry.

10 . The positive electrode slurry of claim 5 , wherein the second binder is included in an amount of 1 to 5 parts by weight with respect to 100 parts by weight of a total amount of the positive electrode slurry.

11 . A positive electrode for a lithium secondary battery, comprising:
a positive electrode current collector; a first positive electrode mixture layer; and a second positive electrode mixture layer, wherein each of the first positive electrode mixture layer and the second positive electrode mixture layer is formed using the positive electrode slurry for the lithium secondary battery according to claim 5 , and wherein the positive electrode has a structure in which the positive electrode current collector, the first positive electrode mixture layer, and the second positive electrode mixture layer are sequentially laminated.

12 . The positive electrode of claim 11 , wherein:
an amount of the lithium cobalt oxide represented by the Chemical Formula 1 contained in the first positive electrode mixture layer ranges from 0.5 to 2.0 parts by weight with respect to 100 parts by weight of the first positive electrode mixture layer; and an amount of the lithium cobalt oxide represented by the Chemical Formula 1 contained in the second positive electrode mixture layer ranges from 0.01 to 0.5 parts by weight with respect to 100 parts by weight of the second positive electrode mixture layer.

13 . The positive electrode of claim 11 , wherein a total amount of the lithium cobalt oxides contained in the first positive electrode mixture layer and the second positive electrode mixture layer is less than or equal to 0.5 parts by weight with respect to 100 parts by weight of a total amount of the first and the second positive electrode active material contained in the first positive electrode mixture layer and the second positive electrode mixture layer.

14 . The positive electrode of claim 11 , wherein a ratio of an average thickness of the first positive electrode mixture layer to an average thickness of the second positive electrode mixture layer ranges from 0.1 to 0.9.

15 . A lithium secondary battery comprising:
the positive electrode according to claim 11 ; a negative electrode; and a separator interposed between the positive electrode and the negative electrode.

Assignees

• Lg Energy Solution Ltd

Inventors

• Kim Ji Hye
• Oh Sang Seung
• Kim Hye Hyeon
• Jo Chi Ho
• Yoo Tae Gu

Classifications

• H01M4/1391

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

• H01M4/366

  as layered products · CPC title

• H01M4/505

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

• H01M4/624 Primary

  Electric conductive fillers · CPC title

• H01M4/525 Primary

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title