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

Patent metadata

Field	Value
Publication number	US-12586780-B2
Application number	US-202217718946-A
Country	US
Kind code	B2
Filing date	Apr 12, 2022
Priority date	Apr 13, 2021
Publication date	Mar 24, 2026
Grant date	Mar 24, 2026

Abstract

A cathode active material for a lithium secondary battery according to an embodiment of the present invention includes a lithium metal oxide particle containing nickel, and a coating material formed on at least a portion of a surface of the lithium metal oxide particle. The coating material includes a metalloid element or a metal element. A surface coating level of the cathode active material is 0.3 or more.

First claim

What is claimed is:

1 . A cathode active material for a lithium secondary battery, comprising:
a lithium metal oxide particle containing nickel; and a coating material formed on at least a portion of a surface of the lithium metal oxide particle, the coating material comprising a metalloid element or a metal element, and wherein a surface coating level expressed as SCL1 in Equation 1 is 0.6 to 3.0, and a surface residual ratio of the coating material is from 40% to 90%, wherein the coating material comprises at least one selected from the group consisting of Al, Ti, Ba, Zr, Si, B, Mg, P, Sr, W and La:

SCL
⁢
1

=

residual
⁢

ratio
⁢

of
⁢

coating
⁢

material

×

surface
⁢

coverage
×
BET

1,000

[

Equation
⁢

1

]

wherein, in Equation 1, the surface residual ratio of the coating material is a percentage equal to a weight of the coating material when the cathode active material is dissolved in a 2 wt % hydrochloric acid solution for a time corresponding to 8% of a time for completely dissolving the cathode active material relative to a weight of the coating material when the cathode active material is completely dissolved in the 2 wt % hydrochloric acid solution,
the coverage is a percentage equal to an area in which a content of the coating material is 0.8 wt % or more based on 100 wt % of total detected elements relative to an area from which Ni is detected based on an energy-dispersive X-ray spectroscopy (EDS) mapping image of a surface of the cathode active material measured by an EDS, and
the BET is a specific surface area of the cathode active material measured by a gas adsorption/desorption method.

2 . The cathode active material for a secondary battery of claim 1 , wherein a content of nickel among all elements excluding lithium and oxygen in the lithium metal oxide particle is 80 mol % or more.

3 . The cathode active material for a secondary battery of claim 1 , wherein the lithium metal oxide particle is represented by Chemical Formula 1:
Li x Ni a Co b M c O y   [Chemical Formula 1]
wherein, in Chemical Formula 1, M comprises at least one selected from the group consisting of Al, Zr, Ti, Cr, B, Mg, Mn, Ba, Si, Y, W and Sr, and 0.9≤x≤1.2, 1.9≤y≤2.1, 0.8≤a≤1, 0≤c≤0.11 and 0≤c/(a+b)≤0.13.

4 . The cathode active material of claim 1 , wherein the coverage is from 5% to 50%.

5 . The cathode active material for a secondary battery of claim 1 , wherein the BET is from 0.25 m 2 /g to 1 m 2 /g.

6 . A cathode for a lithium secondary battery, comprising:
a cathode current collector; and a cathode active material layer formed on the cathode electrode current collector, wherein the cathode active material layer comprises: a lithium metal oxide particle containing nickel; and a coating material formed on at least a portion of a surface of the lithium metal oxide particle, the coating material comprising a metalloid element or a metal element, wherein a surface coating level of the cathode active material layer expressed as SCL2 in Equation 2 is 1.0 to 4.0, and a surface residual ratio of the coating material is from 50% to 80%, wherein the coating material comprises at least one selected from the group consisting of Al, Ti, Ba, Zr, Si, B, Mg, P, Sr, W and La:

S
⁢
C
⁢
L
⁢
2

=

surface
⁢

residual
⁢

ratio
⁢

of
⁢

coating
⁢

material
×

coveragae
×
B
⁢
E
⁢
T

1
⁣

,
000

[

Equation
⁢

2

]

wherein, in Equation 2, the surface residual ratio of the coating material is a percentage equal to a weight of the coating material when the cathode active material layer is dissolved in a 2 wt % hydrochloric acid solution for a time corresponding to 8% of a time for completely dissolving the cathode active material layer relative to a weight of the coating material when the cathode active material layer is completely dissolved in the

Assignees

• Sk On Co Ltd

Inventors

• Lee Sang Wook
• Do Young Hoon
• Park Young Uk
• Cho Yong Hyun
• Lee Seung Ok
• Lee Ji Sun

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