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

Patent metadata

Field	Value
Publication number	US-12151950-B2
Application number	US-202418677903-A
Country	US
Kind code	B2
Filing date	May 30, 2024
Priority date	Dec 7, 2022
Publication date	Nov 26, 2024
Grant date	Nov 26, 2024

Abstract

A cathode active material for a lithium secondary battery has a structure of a lithium-nickel-based metal oxide. A crystal size in a (104) plane defined by Equation 1 is less than 200 nm. A thickness of a TM slab measured by a Rietveld method in a crystal structure of a space group R-3m by an X-ray diffraction (XRD) analysis is 2.15 Å or less. A thickness of a Li slab thickness measured by the Rietveld method in the crystal structure of the space group R-3m by the XRD analysis is 2.585 Å or more.

First claim

What is claimed is:

1. A cathode active material for a lithium secondary battery having a structure of a lithium-nickel-based metal oxide,
wherein a thickness of a TM slab measured by a Rietveld method in a crystal structure of a space group R-3m by an X-ray diffraction (XRD) analysis is in a range from 2.13 Å to 2.15 Å,
wherein a crystal size in a (003) plane defined by Equation 2 below is in a range from 150 nm to 300 nm:

L

0
⁢
0
⁢
3

=

K
⁢
λ

β
003

⁢
cos
⁢
θ

[

Equation
⁢

2

]

wherein, in Equation 2, L 003 is the crystal size (nm) in the (003) plane, K is a shape factor, λ is an X-ray wavelength (nm), B 003 is a full width at half maximum (rad) of a (003) plane peak from the XRD analysis, and θ represents a diffraction angle (rad).

2. The cathode active material for a lithium secondary battery according to claim 1 , wherein the lithium-nickel-based metal oxide has a layered structure or a crystal structure represented by Chemical Formula 1-1:
Li x Ni a CO b1 Mn c1 M1 d1 O 2+y   [Chemical Formula 1-1]

wherein, in Chemical Formula 1-1, M1 includes at least one selected from the group consisting of Na, Mg, Ca, Y, Ti, Hf, V, Nb, Ta, Cr, Mo, W, Fe, Cu, Ag, Zn, B, Al, Ga, C, Si, Sn, Sr, Ba, Ra, P and Zr, 0.8≤x≤1.5,−0.1≤y≤0.1, 0.88≤a≤0.98, 0_b1≤0.1, 0≤c1≤0.1, 0≤d1<0.1 and a+b1+c1+d1=1.

3. The cathode active material for a lithium secondary battery according to claim 2 , wherein b1≥c1 in Chemical Formula 1-1.

4. The cathode active material for a lithium secondary battery according to claim 1 , a thickness of a Li slab measured by the Rietveld method in the crystal structure of the space group R-3m by the XRD analysis is 2.585 Å or more.

5. The cathode active material for a lithium secondary battery according to claim 4 , wherein the thickness of the Li slab is in a range from 2.59 Å to 2.615 Å.

6. The cathode active material for a lithium secondary battery according to claim 4 , wherein a ratio of the thickness of the Li slab to the thickness of the TM slab is in a range from 1.20 to 1.25.

7. The cathode active material for a lithium secondary battery according to claim 1 , wherein a crystal size in a (104) plane defined by Equation 1 is less than 200 nm:

L
104

=

K
⁢
λ

β
104

⁢
cos
⁢
θ

[

Equation
⁢

1

]

wherein, in Equation 1, L 104 is a crystal size (nm) in the (104) plane, K is a shape factor, λ is an X-ray wavelength (nm), β 104 is a full width at half maximum (rad) of a (104) plane peak from the XRD analysis, and θ represents a diffraction angle (rad).

8. The cathode active material for a lithium secondary battery according to claim 7 , wherein the crystal size in the (104) plane defined by Equation 1 is 120 nm or less.

9. The cathode active material for a lithium secondary battery according to claim 7 , wherein the crystal size in the (104) plane defined by Equation 1 is 50 nm or more.

10. The cathode active material for a lithium secondary battery according to claim 7 , wherein a ratio of the crystal size defined by Equation 2 to the crystal size defined by Equation 1 is in a range from 1.5 to 3.

11. The cathode active material for a lithium secondary battery according to claim 7 , wherein a ratio of a peak intensity of a (003) plane to a peak intensity of the (104) plane by the XRD analysis is in a range from 1.8 to 2.2.

12. The cathode active material for a lithium secondary battery according to claim 1 , wherein an a-axis lattice constant and a b-axis lattice constant measured by the Rietveld method in the crystal structure of the space group R-3m by the XRD analysis are the same, and
a ratio of a c-axis lattice constant to the a-axis lattice constant is in a range from 4.8 to 5.2.

13. The cathode active material for a lithium secondary battery according to claim 12 , wherein a volume of a unit cell of the crystal structure is in a range from 101.6 Å 3 to 101.9 Å 3 .

14. A lithium secondary battery, comprising:
a cathode comprising the cathode active material layer for a lithium secondary battery of claim 1 ; and
an anode facing the cathode.

Assignees

• Sk On Co Ltd

Inventors

• Kweon Hee Jun
• Yoon Jeong Bae
• Choi Ji Hoon

Classifications

• C01G53/82 Primary

  Compounds containing nickel, with or without oxygen or hydrogen, and containing two or more other elements · 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

• C01P2002/76

  by a space-group or by other symmetry indications · CPC title

• C01P2002/74

  by peak-intensities or a ratio thereof only · CPC title