Composite cathode active material, cathode and lithium battery including the composite cathode active material, and method of preparing the composite cathode active material

Patent metadata

Field	Value
Publication number	US-2018316009-A1
Application number	US-201815876410-A
Country	US
Kind code	A1
Filing date	Jan 22, 2018
Priority date	Apr 28, 2017
Publication date	Nov 1, 2018
Grant date	—

Abstract

A composite cathode active material, and a cathode and a lithium battery each including the composite cathode active material. The composite cathode active material includes: a core including a first lithium transition metal oxide represented by Formula 1,
Li a MO 2
wherein, in Formula 1, M includes Ni and at least one non-nickel Group 4 to Group 13 element, a content of Ni is about 70 mol % or greater, based on a total content of M, 0.9≤a≤1.1, and wherein the first lithium transition metal oxide has a layered crystal structure belonging to an R 3 m space group; and a shell on a surface of the core, the shell having a spinel crystal structure and including a dopant.

First claim

What is claimed is:

1 . A composite cathode active material comprising:
a core comprising a first lithium transition metal oxide represented by Formula 1
Li a MO 2

wherein, in Formula 1,
M comprises Ni and at least one non-nickel Group 4 to Group 13 element, wherein a content of Ni is about 70 mole percent or greater, based on a total content of M,
0.9≤a≤1.1, and

wherein the first lithium transition metal oxide has a layered crystal structure belonging to an R 3 m space group; and
a shell on a surface of the core, the shell having a spinel crystal structure and comprising a dopant.

2 . The composite cathode active material of claim 1 , wherein the dopant comprises at least one non-nickel Group 4 to Group 13 element.

3 . The composite cathode active material of claim 1 , wherein the shell comprises a second lithium transition metal oxide represented by Formula 2:
Li 1-x M″ y M′ z O 2   Formula 2

wherein, in Formula 2,
M″ comprises Ni and at least one non-nickel Group 4 to Group 13 element,
M′ comprises at least one non-nickel Group 4 to Group 13 element, and
0≤x≤0.05, 0≤z≤0.06, 1.0≤(y+z)≤1.06.

4 . The composite cathode active material of claim 3 , wherein M′ comprises Co, Zn, Fe, Cu, Mn, Zr, Ti, Mg, or a combination thereof.

5 . The composite cathode active material of claim 3 , wherein the second lithium transition metal oxide has electrochemical activity.

6 . The composite cathode active material of claim 1 , wherein the shell has a thickness of about 100 nanometers or less.

7 . The composite cathode active material of claim 1 , wherein a content of the shell is about 6 weight percent or less, based on a total weight of the composite cathode active material.

8 . The composite cathode active material of claim 1 , wherein the spinel crystal structure belongs to an Fd 3 m space group.

9 . The composite cathode active material of claim 1 , wherein a peak intensity ratio of an intensity of a (003) peak to an intensity of a (104) peak of the composite cathode active material is less than a peak intensity ratio of an intensity of a (003) peak to an intensity of a (104) peak of the core.

10 . The composite cathode active material of claim 1 , wherein a maximum peak intensity in a Raman spectrum of the composite cathode active material is positioned at about 530 inverse centimeters or greater.

11 . The composite cathode active material of claim 1 , wherein a peak intensity ratio of an intensity of a peak at about 530 electron volts to 533 electron volts to an intensity of a peak at about 528 electron volts to about 530 electron volts in a surface X-ray photoelectron spectrum of the composite cathode active material is about 2 or less.

12 . The composite cathode active material of claim 1 , wherein the composite cathode active material comprises a polyhedral primary particle, and wherein the polyhedral primary particle comprises the layered crystal structure and the spinel crystal structure.

13 . The composite cathode active material of claim 12 , wherein the polyhedral primary particle comprises a polyhedral pore, which extends from a first surface to an opposite second surface of the polyhedral primary particle.

14 . The composite cathode active material of claim 1 , wherein the composite cathode active material comprises mesopores having a diameter of about 1 nanometer to about 100 nanometers, and wherein the mesopores have an average volume of about 0.001 cubic centimeters per gram.

15 . The composite cathode active material of claim 1 , wherein the composite cathode active material has a specific surface area of about 0.48 square meters per gram or greater.

16 . A composite cathode active material comprising:
a core comprising a first lithium transition metal oxide represented by Formula 1
Li a MO 2   Formula 1

wherein, in Formula 1, M comprises Ni and at least one non-nickel Group 4 to Group 13 element, wherein a content of Ni is about 70 mole percent or greater, based on a total content of M, and 0.9≤a≤1.1, wherein the first lithium transition metal oxide has a layered crystal structure belonging to an R 3 m space group; and a shell on a surface of the core, the shell having a spinel crystal structure and comprising a dopant, and wherein a sum of peak intensities defined as
(Dopant peak intensity+Co peak intensity)/(Mn peak intensity)

before and after Ar + sputtering when analyzed by surface X-ray photoelectron spectroscopy of the composite cathode active material is about 5 or greater.

17 . The composite cathode active material of claim 16 , wherein the dopant comprises at least one non-nickel Group 4 to Group 13 element.

18 . The composite cathode active material of claim 16 , wherein the shell comprises a second lithium transition metal oxide represented by Formula 2:
Li 1-x M″ y M′ z O 2   Formula 2

wherein, in Formula 2,
M″ comprises Ni and at least one non-nickel Group 4 to Group 13 element,
M′ comprises at least one non-nickel Group 4 to Group 13 element,
0≤x≤0.05, 0≤z≤0.06, and 1.0≤(y+z)≤1.06.

19 . The composite cathode active material of claim 16 , wherein M′ comprises Co, Zn, Fe, Cu, Mn, Zr, Ti, Mg, or a combination thereof.

20 . The composite cathode active material of claim 16 , wherein the first lithium transition metal oxide is represented by Formula 3:
Li a Ni b M1 c M2 d M3 e O 2   Formula 3

wherein, in Formula 3,
M1, M2, and M3 are different and each independently comprises manganese, vanadium, chromium, iron, cobalt, zirconium, rhenium, aluminum, boron, germanium, ruthenium, tin, titanium, niobium, molybdenum, or platinum,
0.9≤a≤1.1, 0.7<b<1.0, 0<c<0.3, 0<d<0.4, 0≤e<0.3, and b+c+d+e=1.

21 . The composite cathode active material of claim 16 , wherein the first lithium transition metal oxide is represented by Formula 4:
Li a Ni b Co c Mn d M3′ e O 2   Formula 4

wherein, in Formula 4, M3′ comprises vanadium, chromium, iron, zirconium, rhenium, aluminum, boron, germanium, ruthenium, tin, titanium, niobium, molybdenum, or platinum,
0.9≤a≤1.1, 0.7<b<1.0, 0<c<0.3, 0<d<0.4, 0≤e<0.3, and b+c+d+e=1.

22 . A cathode comprising a composite cathode active material according to claim 1 .

23 . A lithium battery comprising:
the cathode of claim 22 , an anode, and an electrolyte between the cathode and the anode.

24 . A method of preparing a composite cathode active material, the method comprising:
mixing a metal-organic framework and a first lithium transition metal oxide represented by Formula 1 to prepare a mixture
Li a MO 2   Formula 1

wherein, in Formula 1,
M comprises Ni and at least one non-nickel Group 4 to Group 13 element,
a content of Ni is about 70 mole percent or greater, based on a total content of M, and
0.9≤a≤1.1, and

wherein the first lithium transition metal oxide has a layered crystal structure belonging to an R 3 m space group; and
thermally treating the mixture under an oxidizing atmosphere at about 650° C. to about 800° C. for about 3 hours to about 20 hours to prepare the composite cathode active material.

25 . The method of claim 24 , wherein the metal-organic framework comprises Co, Zn, Fe, Cu, Ni, Mn, Zr, Ti, Mg, or a combination thereof.

26 . The method of claim 24 , wherein the metal-organic framework comprises a polyhedral primary particle, and w

Assignees

• Samsung Electronics Co Ltd
• Samsung Sdi Co Ltd

Inventors

• Park Junho
• Park Kwangjin
• Son Youhwan
• Lee Kanghee
• Hong Sukgi
• Choi Byungjin

Classifications

• H01M4/505

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

• H01M4/1391

  of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title

• C01P2002/32

  spinel-type (AB2O4) · CPC title

• H01M4/131

  Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title

• H01M4/366 Primary

  as layered products · CPC title