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

Patent metadata

Field	Value
Publication number	US-2023082796-A1
Application number	US-202217900655-A
Country	US
Kind code	A1
Filing date	Aug 31, 2022
Priority date	Sep 1, 2021
Publication date	Mar 16, 2023
Grant date	—

Abstract

Provided are a cathode active material for a lithium secondary battery, a method of preparing the same, and a lithium secondary battery containing a cathode including the cathode active material, in which the cathode active material includes nickel-based lithium metal oxide containing single-crystal particles, and a particle size of the single-crystal particles is about 1 μm to about 8 μm, and a particle size distribution of the single-crystal particles expressed by (D90-D10)/D50 is 1.4 or less.

First claim

What is claimed is:

1 . A cathode active material for a lithium secondary battery, the cathode active material comprising:
a nickel-based lithium metal oxide containing single-crystal particles, wherein a particle size of the single-crystal particles is about 1 μm to about 8 μm, and a particle size distribution of the cathode active material expressed by (D90-D10)/D50 is 1.4 or less.

2 . The cathode active material of claim 1 , wherein
the particle size distribution is about 1.0 to about 1.4.

3 . The cathode active material of claim 1 , wherein
the D50 of the cathode active material is about 2 μm to about 4 μm.

4 . The cathode active material of claim 1 , wherein
the D10 of the cathode active material is about 1.2 μm to about 2 μm, and D90 of the cathode active material is about 4 μm to about 7 μm.

5 . The cathode active material of claim 1 , wherein
the nickel-based lithium metal oxide is a compound represented by Formula 1:
Li a (Ni 1−x−y M1 x M2 y )O 2±α1   Formula 1

wherein, in Formula 1, M1 is at least one element selected from Co, Mn, and Al, M2 is at least one element selected from boron (B), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), titanium (Ti), vanadium (V), chromium (Cr), iron (Fe), copper (Cu), and zirconium (Zr), and 0.95≤a≤1.1, 0.6≤(1−x−y)<1, 0≤x<0.4, 0≤y<0.4, and 0≤α1≤0.1, wherein a case where both x and y are 0 excluded.

6 . The cathode active material of claim 5 , wherein
the nickel-based lithium metal oxide is a compound represented by Formula 2:
Li a (Ni 1−x−y−z Co x M3 y M4 z )O 2± α1   Formula 2

wherein, in Formula 2, M3 is at least one element selected from Mn and Al, M4 is at least one element selected from boron (B), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), titanium (Ti), vanadium (V), chromium (Cr), iron (Fe), copper (Cu), and zirconium (Zr), and 0.95≤a≤1.1, 0.6≤(1−x−y−z)<1, 0≤x<0.4, 0≤y<0.4, 0≤z<0.4, and 0≤α1≤0.1, wherein a case where x, y, and z are each 0, is excluded.

7 . The cathode active material of claim 1 , wherein
the particle size of the single-crystal particles is about 2 μm to about 6 μm.

8 . The cathode active material of claim 1 , wherein
the cathode active material further comprises an aggregate of 10 or fewer primary particles.

9 . The cathode active material of claim 1 , wherein
I (003) /I (104) , which is a peak intensity ratio measured by X-ray diffraction analysis, is about 1.2 to about 4.0.

10 . The cathode active material of claim 1 , wherein
W (003) /W (104) obtained in X-ray diffraction analysis of the cathode active material is about 1.01 to about 1.09.

11 . The cathode active material of claim 1 , wherein
the cathode active material further comprises a cobalt compound-containing coating layer on a surface of the nickel-based lithium metal oxide.

12 . The cathode active material of claim 11 , wherein
an amount of a cobalt compound included in the cobalt compound-containing coating layer is about 0.1 mol % to about 5.0 mol % based on the total amount of the cathode active material.

13 . The cathode active material of claim 11 , wherein
a thickness of the cobalt compound-containing coating layer is about 1 nm to about 50 nm.

14 . The cathode active material of claim 11 , wherein
a cobalt compound included in the cobalt compound-containing coating layer is cobalt oxide, lithium cobalt oxide, or a combination thereof.

15 . The cathode active material of claim 11 , wherein
the cobalt compound-containing coating layer further comprises at least one element selected from boron, manganese, phosphorus, aluminum, zinc, zirconium, and titanium.

16 . A method of preparing a cathode active material for a lithium secondary battery, the method comprising:
obtaining a nickel-based metal precursor having pores therein by a co-precipitation reaction of a nickel precursor and at least one compound selected from an M1 precursor and an M2 precursor, and then drying the resultant; obtaining a mixture of the nickel-based metal precursor having pores therein and a lithium precursor; performing a first heat treatment on the mixture to obtain porous oxide particles; and pulverizing the porous oxide particles, wherein the M1 precursor is at least one compound selected from a cobalt precursor, a manganese precursor, and an aluminum precursor, and the M2 precursor is a precursor including at least one element selected from boron (B), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), titanium (Ti), vanadium (V), chromium (Cr), iron (Fe), copper (Cu), and zirconium (Zr).

17 . The method of claim 16 , wherein
the co-precipitation reaction is performed using a complexing agent and a pH-adjusting agent, and the complexing agent is aqueous ammonia, citric acid, or a combination thereof, and the pH-adjusting agent is sodium hydroxide (NaOH), sodium carbonate (Na 2 CO 3 ), sodium oxalate (Na 2 C 2 O 4 ), or a combination thereof.

18 . The method of claim 16 , further comprising performing a second heat treatment after the pulverizing, wherein
the first heat treatment is performed at a higher temperature than the second heat treatment.

19 . The method of claim 16 , wherein
the nickel-based metal precursor having pores therein has an amorphous state, and the nickel-based metal precursor is a secondary particle, and a particle size of the secondary particle is about 7 μm to about 20 μm.

20 . The method of claim 16 , wherein
the nickel-based metal precursor having pores therein is a compound represented by Formula 3, a compound represented by Formula 4, or a combination thereof:
(Ni 1−x−y M1 x M2 y )(OH) 2   Formula 3

wherein, in Formula 3, M1 is at least one element selected from Co, Mn, and Al, M2 is at least one element selected from boron (B), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), titanium (Ti), vanadium (V), chromium (Cr), iron (Fe), copper (Cu), zirconium (Zr), and aluminum (Al), and 0.6≤(1−x−y)<1, 0≤x<0.4, and 0≤y<0.4, wherein a case where both x and y are 0 is excluded,
(Ni 1−x−y M1 x M2 y )O   Formula 4

wherein, in Formula 4, M1 is at least one element selected from Co, Mn, and Al, M2 is at least one element selected from boron (B), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), titanium (Ti), vanadium (V), chromium (Cr), iron (Fe), copper (Cu), zirconium (Zr), and aluminum (Al), and 0.6≤(1−x−y)<1, 0≤x<0.4, and 0≤y<0.4, wherein a case where both x and y are 0 is excluded.

21 . The method of claim 16 , wherein
the nickel-based metal precursor is a compound represented by Formula 5, a compound represented by Formula 6, or a combination thereof:
Ni 1−x−y−z Co x M3 y M4 z (OH) 2   Formula 5

wherein, in Formula 5, M3 is at least one element selected from Mn and Al, M4 is at least one element selected from boron (B), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), titanium (Ti), vanadium (V), chromium (Cr), iron (Fe), copper (Cu), zirconium (Zr), and aluminum (Al), and 0.6≤(1−x−y−z)<1, 0≤x<0.4, 0≤y<0.4, and 0≤z<0.4, wherein a case where x, y, and z are each 0, is excluded,
(Ni 1−x−y−z Co x M3 y M4 z )O   Formula 6

wherein, in Formula 6, M3 is at least one element selected from Mn and Al, M4 is at least one element selected from boron (B), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), titanium (Ti), vanadium (V), chromium (Cr), iron (Fe), copper (Cu), and zirconium (Zr), and 0.6≤(1−x−y−z)<1, 0≤x<0.4, 0≤y<0.4, and 0≤z<0

Assignees

• Samsung Sdi Co Ltd

Inventors

• Lee Dookyun
• Kang Byungwuk
• Kim Sungsoo
• Kim Saehwan
• Kim Soohyeon
• You Yongchan
• Lee Jangwook
• Cha Minah
• Choi Seungyeon

Classifications

• 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

• H01M4/62

  Selection of inactive substances as ingredients for active masses, e.g. binders, fillers · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M4/366

  as layered products · CPC title

• H01M2004/028

  Positive electrodes · CPC title