Positive electrode active material for secondary battery and lithium secondary battery including the same

Patent metadata

Field	Value
Publication number	US-12537196-B2
Application number	US-202117795049-A
Country	US
Kind code	B2
Filing date	Jan 19, 2021
Priority date	Jan 29, 2020
Publication date	Jan 27, 2026
Grant date	Jan 27, 2026

Abstract

A positive electrode active material, and a positive electrode and a lithium secondary battery including the same are disclosed herein. In some embodiments, a positive electrode active material includes a lithium composite transition metal oxide containing nickel, cobalt, and manganese and having a nickel content for 60 mol % or more, based on metals (M) excluding lithium, and is in the form of single particles having an average particle diameter (D 50 ) of 1 to 10 μm, wherein a 100-nm region extending from the surface toward the center of a single particle has crystal structures of a Fd3M and a Fm3m space group, and a phase ratio is 0.2 to 0.7, which is a ratio of a first portion of a maximum straight length of the 100-nm region occupied by the crystal structure of the Fd3M space group to a second portion occupied by the crystal structure of the Fm3m space group.

First claim

The invention claimed is:

1 . A positive electrode active material for a secondary battery, comprising:
a lithium composite transition metal oxide comprising a center and a 100-nm region extending from a surface toward the center, wherein the lithium composite transition metal oxide contains nickel, cobalt, and manganese and has a nickel content accounting for 60 mol % or more, based on the metals (M) contained in the lithium composite transition metal oxide, wherein M excludes lithium, wherein the lithium composite transition metal oxide is in the form of single particles having an average particle diameter (D 50 ) of from 1 to 10 μm, wherein the 100-nm region extending from the surface toward the center of a single particle comprises crystal structures of a Fd3M space group and a Fm3m space group, wherein the center of the single particle comprises a layered crystal structure, wherein the 100-nm region extending from the surface toward the center of the single particle comprises nickel, cobalt, and manganese, and the center of the single particle comprises nickel, cobalt, and manganese, wherein a phase ratio is from 0.2 to 0.7 wherein the phase ratio is a ratio of maximum straight lengths of respective portions occupied by the Fd3M space group and the crystal structure of the Fm3m space group in the 100-nm region extending from the surface toward the center of the single particle, and wherein the maximum straight length is determined from a cross-sectional image of the surface of a single particle, wherein the image is obtained using transmission electron microscopy (TEM), and wherein the maximum straight length is measured perpendicular to the surface of the single particle.

2 . The positive electrode active material of claim 1 , wherein the phase ratio is from 0.3 to 0.6.

3 . The positive electrode active material of claim 1 , wherein the average particle diameter (D 50 ) is from 2 to 7 μm.

4 . The positive electrode active material of claim 1 , wherein a cation mixing ratio of nickel cations in a lithium layer in the structure of the lithium composite transition metal oxide is 1.5% or less.

5 . The positive electrode active material of claim 4 , wherein a cation mixing ratio of nickel cations in a lithium layer in the structure of the lithium composite transition metal oxide is 1.0% or less.

6 . The positive electrode active material of claim 1 , wherein a molar ratio of lithium (Li) to M in the lithium composite transition metal oxide is from 1.1 to 1.2.

7 . The positive electrode active material of claim 1 , wherein the lithium composite transition metal oxide is represented by the following Chemical Formula 1:
Li a Ni 1-b-c-d Co b Mn c Q d O 2+8   [Chemical Formula 1]
in Chemical Formula 1, Q is one or more elements selected from the group consisting of Al, Mg, V, Ti, and Zr, and 1.0≤a≤1.2, 0<b≤0.4, 0<c≤0.3, 0≤d<0.1, 0<b+c+d≤0.4, and −0.1≤8≤1.0.

8 . A positive electrode for a secondary battery, comprising the positive electrode active material according to claim 1 .

9 . A lithium secondary battery comprising the positive electrode according to claim 8 .

10 . The positive electrode active material of claim 1 , wherein the single particle is formed of at most 10 primary particles.

Assignees

• Lg Energy Solution Ltd

Inventors

• Park Sang Min
• Lho Eun Sol
• Park Sung Bin
• Kim Seul Ki
• Wang Wen Xiu
• Jung Wang Mo

Classifications

• H01M2220/20

  Batteries in motive systems, e.g. vehicle, ship, plane · CPC title

• H01M2004/028

  Positive electrodes · CPC title

• H01M2004/021

  Physical characteristics, e.g. porosity, surface area · CPC title

• H01M10/0525

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

• H01M4/505

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