Cathode active material for lithium secondary battery and lithium secondary battery including the same

Patent metadata

Field	Value
Publication number	US-12555768-B2
Application number	US-202117522361-A
Country	US
Kind code	B2
Filing date	Nov 9, 2021
Priority date	Nov 9, 2020
Publication date	Feb 17, 2026
Grant date	Feb 17, 2026

Abstract

The cathode active material for a lithium secondary battery includes lithium-transition metal composite oxide particles having a crystal grain size of less than 300 nm measured through XRD analysis and an XRD peak intensity ratio of 7% or more. The present invention provides a lithium secondary battery with improved life-span properties and output properties by controlling the crystal grain size and XRD peak intensity ratio of lithium-transition metal composite oxide particles.

First claim

What is claimed is:

1 . A cathode active material for a lithium secondary battery, comprising lithium-transition metal composite oxide particles having a crystal grain size measured through X-ray diffraction (XRD) analysis of 100 nm or more and less than 300 nm and having an XRD peak intensity ratio defined by Equation 2 of 9% to 11%,
wherein the lithium-transition metal composite oxide particles include nickel, cobalt and manganese, and a molar ratio of nickel of the lithium-transition metal oxide particles based on total moles of metals excluding lithium is 0.8 or more:
XRD peak intensity ratio (%)=100× I (110)/{ I (110)+ I (003)}  [Equation 2]

wherein, in Equation 2, I(110) is a maximum height of a peak of a (110) plane of the lithium-transition metal composite oxide particles by the XRD analysis, and I(003) is a maximum height of a peak of a (003) plane of the lithium-transition metal composite oxide particles by the XRD analysis, and wherein the crystal grain size is measured through Equation 1:

L
=

0
.
9

⁢
λ

β
⁢
cos
⁢

⁢
θ

[

Equation
⁢

⁢
1

]

wherein, in Equation 1, L is the crystal grain size in nm, λ is an X-ray wavelength in nm, β is a full width at half maximum (rad) of the peak of the (003) plane, and θ is a diffraction angle in radian.

2 . The cathode active material for a lithium secondary battery according to claim 1 , wherein the lithium-transition metal composite oxide particles have the crystal grain size of 150 to 265 nm.

3 . The cathode active material for a lithium secondary battery according to claim 1 , wherein the lithium-transition metal composite oxide particles have an XRD peak area ratio defined by Equation 3 of 16% or more:
XRD peak area ratio (%)=100× A (110)/{ A (110)+ A (003)}  [Equation 3]
wherein, in Equation 3, A(110) is a peak area of the (110) plane of the lithium-transition metal composite oxide particles by the X-ray diffraction (XRD) analysis, and A(003) is a peak area of the (003) plane by the XRD analysis.

4 . The cathode active material for a lithium secondary battery according to claim 3 , wherein the lithium-transition metal composite oxide particles have the XRD peak area ratio of 16 to 19%.

5 . The cathode active material for a lithium secondary battery according to claim 1 , wherein the lithium-transition metal composite oxide particles have a particle diameter (D 50 ) of 3 to 16 μm.

6 . The cathode active material for a lithium secondary battery according to claim 1 , wherein the lithium-transition metal composite oxide particles have a particle diameter of 10 to 15 μm.

7 . The cathode active material for a lithium secondary battery according to claim 1 , wherein the lithium-transition metal composite oxide particles have a composition represented by Formula 1 below:
Li x Ni 1−y MyO 2+z   [Formula 1]
wherein, in Formula 1, x, y and z are in a range of 0.95x≤1.2, 0≤y≤0.2, and −0.1≤z≤0.1, respectively, and M is Co and Mn.

8 . The cathode active material for a lithium secondary battery according to claim 7 , wherein the lithium-transition metal composite oxide particles are prepared by reacting a transition metal precursor with a lithium precursor.

9 . The cathode active material for a lithium secondary battery according to claim 8 , wherein the transition metal precursor is a Ni—Co—Mn precursor.

10 . The cathode active material for a lithium secondary battery according to claim 7 , wherein y of Formula 1 is 0.1 or less.

11 . The cathode active material for a lithium secondary battery according to claim 1 , wherein the lithium-transition metal composite oxide particles have a coating element,
and the coating element includes at least one element selected from a group consisting of Al, Ti, Ba, Zr, Si B, Mg and P.

12 . The cathode active material for a lithium secondary battery according to claim 1 , wherein the lithium-transition metal composite oxide particles have a doping element,
and the doping element includes at least one element selected from a group consisting of Al, Ti, Ba, Zr, Si B, Mg and P.

13 . A lithium secondary battery comprising:
a cathode comprising a cathode active material layer including the cathode active material according to claim 1 ; and an anode facing the cathode.

14 . The lithium secondary battery of claim 13 , wherein the anode comprises an anode current collector and an anode active material layer coating the anode current collector.

Assignees

• Sk Innovation Co Ltd
• Sk On Co Ltd

Inventors

• Lee Yoon Ji
• Lee Sang Han
• Kang Min Suk
• Cho Yong Hyun

Classifications

• H01M2004/027

  Negative electrodes · 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 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

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M2004/028

  Positive electrodes · CPC title