Positive electrode active material, and positive electrode and lithium secondary battery including same

Patent metadata

Field	Value
Publication number	US-12322797-B2
Application number	US-202017768548-A
Country	US
Kind code	B2
Filing date	Oct 23, 2020
Priority date	Oct 23, 2019
Publication date	Jun 3, 2025
Grant date	Jun 3, 2025

Abstract

A positive electrode active material, a positive electrode including the positive electrode active material, and a lithium secondary battery including the same are disclosed herein. In some embodiments, the positive electrode active material includes a lithium transition metal oxide containing nickel in an amount of 60 mol % or greater based on a total number of moles of transition metals in the lithium transition metal oxide, and in the form of a secondary particle which is an aggregate of primary particles. The positive active material satisfies Equation (1): −0.021x+4.0≤y≤−0.021x+5.5, wherein x is a crystal grain size (nm) of the positive electrode active material, and y is a crystal grain aspect ratio of the positive electrode active material.

First claim

The invention claimed is:

1. A positive electrode active material, comprising:
a lithium transition metal oxide,
wherein the lithium transition metal oxide contains nickel in an amount of 60 mol % or greater based on a total number of moles of transition metals on the lithium transition metal oxide,
wherein the lithium transition metal oxide is in the form of a secondary particle, wherein the secondary particle is an aggregate of primary particles, and
wherein the positive electrode active material satisfies Equation (1) below:
−0.021 x+ 4.0≤ y≤− 0.021 x+ 5.5,  Equation (1)

wherein in Equation (1), x is a crystal grain size (nm) of the positive electrode active material, and y is a crystal grain aspect ratio of the positive electrode active material,
wherein x is obtained by fitting a full width at half-maximum (FWHM) of all peaks, obtained by X-ray diffraction (XRD) analysis on the positive electrode active material, with the Caglioti equation, and
wherein y is a ratio of a long axis length (a) to a short axis length (c) obtained by a least square estimation method after applying a full width at half-maximum (FWHM) of each peak, obtained by performing X-ray diffraction (XRD) analysis on the positive electrode active material, to Equation (2) below:

d

(

h
⁢
k
⁢
l

)

=

K
⁢
λ

2
⁢
cos
⁢
θ
⁢

{

acos
⁢

(

tan

-
1

(

a
c

⁢

tan
⁡
(

l
2

h
2

+

k
2

)

)

)

}

2

+

{

c
⁢
sin
⁢

(

tan

-
1

⁢

(

a
c

⁢
tan
⁢

(

l
2

h
2

+

k
2

)

)

)

Assignees

• Lg Chemical Ltd

Inventors

• Jung Won Sig
• Lee Kang Hyeon
• Rhee Tae Young
• Choi Hwan Young

Classifications

• 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

• H01M4/525

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

• H01M4/505

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