Positive Electrode Material, and Positive Electrode and Lithium Secondary Battery Which Include the Same

Patent metadata

Field	Value
Publication number	US-2025158022-A1
Application number	US-202318838147-A
Country	US
Kind code	A1
Filing date	Feb 15, 2023
Priority date	Feb 15, 2022
Publication date	May 15, 2025
Grant date	—

Abstract

A positive electrode material for a lithium secondary battery includes: a first positive electrode active material and a second positive electrode active material. The first positive electrode active material includes a lithium transition metal oxide in which a molar ratio of nickel among transition metals is 70 mol % or more, the second positive electrode active material includes a lithium transition metal oxide in which a molar ratio of nickel among transition metals is 25 mol % or more less than the molar ratio of the nickel among the transition metals of the first positive electrode active material, an average particle diameter of primary particles constituting the second positive electrode active material is larger than an average particle diameter of primary particles constituting the first positive electrode active material, and D 50 of the second positive electrode active material is smaller than D 50 of the first positive electrode active material.

First claim

1 . A positive electrode material for a lithium secondary battery, comprising:
a first positive electrode active material and a second positive electrode active material, wherein the first positive electrode active material comprises a first lithium transition metal oxide having a molar ratio of nickel of 70 mol % or more relative to a total amount of transition metals of the first lithium transition metal oxide, wherein the second positive electrode active material comprises a second lithium transition metal oxide having a molar ratio of nickel of 25 mol % or more less than the molar ratio of the nickel of the first lithium transition metal oxide, wherein an average particle diameter of primary particles constituting the second positive electrode active material is larger than an average particle diameter of primary particles constituting the first positive electrode active material, and wherein D 50 of the second positive electrode active material is smaller than D 50 of the first positive electrode active material.

2 . The positive electrode material of claim 1 , wherein the molar ratio of the nickel in the second lithium transition metal oxide relative to a total amount of transition metals of the second lithium transition metal oxide is from 40 mol % to 65 mol %.

3 . The positive electrode material of claim 1 , wherein the first lithium transition metal oxide is represented by Formula 1:
Li 1+x (Ni a CO b Mn c M d )O 2   [Formula 1]
wherein, M is at least one of W, Cu, Fe, V, Cr, Ti, Zr, Zn, Al, In, Ta, Y, La, Sr, Ga, Sc, Gd, Sm, Ca, Ce, Nb, Mg, B, or Mo, and x, a, b, c, and d respectively satisfy −0.2≤x≤0.2, 0.70≤a<1, 0<b≤0.20, 0<c≤0.20, 0≤d≤0.10, and a+b+c+d=1.

4 . The positive electrode material of claim 1 , wherein the second lithium transition metal oxide is represented by Formula 2:
Li 1+y (Ni e Co f Mn g M′ h )O 2   [Formula 2]
wherein, M′ is at least one doping element of W, Cu, Fe, V, Cr, Ti, Zr, Zn, Al, In, Ta, Y, La, Sr, Ga, Sc, Gd, Sm, Ca, Ce, Nb, Mg, B, or Mo, and y, e, f, g, and h respectively satisfy −0.2≤y≤0.2, 0.40≤e≤0.65, 0.10≤f≤0.40, 0.10≤g≤0.40, 0≤h≤0.10, and e+f+g+h=1.

5 . The positive electrode material of claim 1 , wherein the average particle diameter of the primary particles constituting the first positive electrode active material is from 0.1 μm to 1 μm.

6 . The positive electrode material of claim 1 , wherein the average particle diameter of the primary particles constituting the second positive electrode active material is 1 μm to 3 μm.

7 . The positive electrode material of claim 1 , wherein the D 50 of the first positive electrode active material is from 8 μm to 20 μm.

8 . The positive electrode material of claim 1 , wherein the D 50 of the second positive electrode active material is from 1 μm to less than 8 μm.

9 . The positive electrode material of claim 1 , wherein an absolute value of a difference between a rate of change in c-axis length according to Equation 1 of the first positive electrode active material and a rate of change in c-axis length according to Equation 1 of the second positive electrode active material is from 0% to 10%:

Rate
⁢

of
⁢

change
⁢

in
⁢

c
-
axis
⁢

length
⁢

(
%
)

=

{

(

C

o
⁢
1

-

C

1
⁢
o

)

/

C
o

)

×
1
⁢
0
⁢
0

}

[

Equation
⁢

1

]

wherein,
C o is a c-axis length of the positive electrode active material in an uncharged state, and C 1 is a c-axis length of the positive electrode active material in a state of being charged to 4.2 V.

10 . The positive electrode material of claim 1 , wherein the positive electrode material comprises the first positive electrode active material and the second positive electrode active material in a weight ratio of from 50:50 to 99:1.

11 . A positive electrode for a lithium secondary battery, comprising the positive electrode material of claim 1 .

12 . A lithium secondary battery comprising the positive electrode of claim 11 .

Assignees

• Lg Energy Solution Ltd

Inventors

• Park Kang Joon
• Baek So Ra
• Jung Wang Mo
• Park Sin Young
• Hur Hyuck
• Kim Dong Hwi
• Kwak Min
• Chae Seul Ki

Classifications

• H01M2004/028

  Positive electrodes · CPC title

• H01M2004/021

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

• H01M10/052 Primary

  Li-accumulators · 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

• H01M4/505

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