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-2017358797-A1
Application number	US-201715622133-A
Country	US
Kind code	A1
Filing date	Jun 14, 2017
Priority date	Jun 14, 2016
Publication date	Dec 14, 2017
Grant date	—

Abstract

A composite cathode active material, includes a first metal oxide having a first layered crystal structure; and a second metal oxide having a second layered crystal structure, wherein the second metal oxide includes a layered double oxide (LDO). Also a cathode and a lithium battery including the composite cathode active material.

First claim

What is claimed is:

1 . A composite cathode active material, comprising:
a first metal oxide having a first layered crystal structure; and a second metal oxide having a second layered crystal structure, wherein the second metal oxide comprises a layered double oxide.

2 . The composite cathode active material of claim 1 comprising:
a core, which comprises the first metal oxide; and
a coating layer, which comprises the second metal oxide and is disposed on a surface of the core.

3 . The composite cathode active material of claim 2 , wherein the coating layer is disposed on a portion of an outer surface of the core.

4 . The composite cathode active material of claim 1 , wherein the second metal oxide is attached to the first metal oxide by a chemical bond.

5 . The composite cathode active material of claim 1 ,
wherein a structure of the first metal oxide has a first space group, wherein a structure of the second metal oxide has a second space group, and wherein the first space group and the second space group are different.

6 . The composite cathode active material of claim 1 ,
wherein the structure of the first metal oxide belongs to space group C2/m, and wherein structure of the second metal oxide belongs to space group R3m.

7 . The composite cathode active material of claim 1 ,
wherein the second metal oxide comprises a metal, and wherein the metal occupies a crystallographic site of the second metal oxide having octahedral coordination.

8 . The composite cathode active material of claim 1 , wherein the second metal oxide comprises a layered double hydroxide that is represented by Formula 1:
M1 a M2 b M3 c O 4   Formula 1

wherein, in Formula 1,
0≦a≦2, 0<c≦2, and b+c=3;
M1 is an alkali metal,
M2 is a metal and comprises an element of Groups 2, 9, 10, 11, or 12, and
M3 is a metal and comprises an element of Groups 3, 4, 5, 8, or 13.

9 . The composite cathode active material of claim 1 , wherein the second metal oxide comprises a layered double oxide that is represented by Formula 2:
Li a M2 b M3 c O 4   Formula 2

wherein, in Formula 2,
0≦a≦2, 0<c≦2, b>c, and b+c=3;
M2 is a metal and comprises Co, Mg, Ni, Cu, and Zn, and
M3 is a metal and comprises Ce, Al, Fe, V, Ti, and Ga.

10 . The composite cathode active material of claim 1 , wherein the layered double oxide of the second metal oxide comprises LiCo 2 CeO 4 , LiMg 2 CeO 4 , LiNi 2 CeO 4 , LiCu 2 CeO 4 , LiZn 2 CeO 4 , LiCo 2 AlO 4 , LiMg 2 AlO 4 , LiNi 2 AlO 4 , LiCu 2 AlO 4 , LiZn 2 AlO 4 , LiCo 2 FeO 4 , LiMg 2 FeO 4 , LiNi 2 FeO 4 , LiCu 2 FeO 4 , LiZn 2 FeO 4 , LiCo 2 VO 4 , LiMg 2 VO 4 , LiNi 2 VO 4 , LiCu 2 VO 4 , LiZn 2 VO 4 , LiCo 2 TiO 4 , LiMg 2 TiO 4 , LiNi 2 TiO 4 , LiCu 2 TiO 4 , LiZn 2 TiO 4 , LiCo 2 GaO 4 , LiMg 2 GaO 4 , LiNi 2 GaO 4 , LiCu 2 GaO 4 , LiZn 2 GaO 4 , or a combination thereof.

11 . The composite cathode active material of claim 1 , wherein an interval between metal oxide layers of the layered double oxide is in a range of about 1 Angstrom to about 10 Angstroms.

12 . The composite cathode active material of claim 1 , wherein an amount of the second metal oxide is in a range of about 0.05 parts to about 20 parts by weight, based on 100 parts by weight of the first metal oxide.

13 . The composite cathode active material of claim 2 , wherein a thickness of the coating layer is 200 nanometers or less.

14 . The composite cathode active material of claim 1 , wherein a caloric value of the composite is 90% or less of a caloric value of the first metal oxide.

15 . The composite cathode active material of claim 1 , wherein an amount of lithium remaining on the surface of the composite is 90% or less than an amount of lithium remaining on the surface of the first metal oxide.

16 . The composite cathode active material of claim 1 , wherein a zeta potential of the composite is in a range of about −20 millivolts to about +20 millivolts at a pH in a range of about 9 to about 11.

17 . The composite cathode active material of claim 1 , wherein the composite has a vibration peak in a range of about 730 cm −1 to about 770 cm −1 in an IR-spectrum of the composite.

18 . The composite cathode active material of claim 1 , wherein a Raman shift of a peak corresponding to an Eg band of the Raman spectrum of the composite is greater than a Raman shift of a peak corresponding to an Eg band of the first metal oxide.

19 . The composite cathode active material of claim 1 , wherein the first metal oxide comprises a compound that is represented by Formula 3:
Li x M y O z   Formula 3

wherein, in Formula 3,
0≦x≦3, 1≦y≦3, and 2≦z≦8; and
M comprises an element of Group 2 to Group 13, or a combination thereof.

20 . The composite cathode active material of claim 1 , wherein the first metal oxide comprises a compound that is represented by one of Formulas 4 to 6:
Li x Co 1−y M y O 2−α X α   Formula 4
Li x Ni 1−y Me y O 2−α X α   Formula 5
Li x Ni 1−y−z Mn y Ma z O 2−α X α   Formula 6

wherein, in Formulas 4 to 6,
0.90≦x≦1.1, 0≦y≦0.9, 0<z≦0.2, and 0≦α≦2;
M comprises Ni, Mn, Zr, Al, Mg, Ag, Mo, Ti, V, Cr, Fe, Cu, B, or a combination thereof,
Me comprises Co, Zr, Al, Mg, Ag, Mo, Ti, V, Cr, Mn, Fe, Cu, B, or a combination thereof,
Ma comprises Co, Zr, Al, Mg, Ag, Mo, Ti, V, Cr, Fe, Cu, B, or a combination thereof, and
X comprises O, F, S, P, or a combination thereof.

21 . The composite cathode active material of claim 1 , wherein the first metal oxide comprises a compound that is represented by Formula 7:
Li x Ni 1−y−z Mn y Co z O 2   Formula 7

wherein, in Formula 7,
0.90≦x≦1.1, 0≦y≦0.2, 0/21 z≦0.2, and 0.7≦1−y−z≦0.99.

22 . The composite cathode active material of claim 1 , wherein the first metal oxide comprises a compound that is represented by one of Formulas 8 to 10:
Li[Li 1−a Me a ]O 2+d   Formula 8

wherein, in Formula 8,
0.8≦a<1 and 0≦d≦0.1; and
Me comprises Ni, Co, Mn, Al, V, Cr, Fe, Zr, Re, B, Ge, Ru, Sn, Ti, Nb, Mo, Pt, or a combination thereof,
Li[Li 1−x−y−z Ma x Mb y Mc z ]O 2+d   Formula 9

wherein, in Formula 9,
0.8≦x+y+z<1, 0/21 x<1, 0<y<1, 0<z<1, and 0≦d≦0.1; and
Ma, Mb, and Mc each independently comprise Mn, Co, Ni, Al, or a combination thereof,
Li[Li 1−x−y−z Ni x Co y Mn z ]O 2+d   Formula 10

wherein, in Formula 10,
0.8≦x+y+z<1; 0<x<1, 0<y<1, 0<z<1, and 0≦d≦0.1.

23 . A cathode comprising the composite cathode active material of claim 1 .

24 . A lithium battery comprising the cathode of claim 22 .

25 . A method of preparing a composite cathode active material, the method comprising:
contacting a layered double hydroxide and a first metal oxide having a first layered crystal structure to prepare a mixture; and calcining the mixture to prepare the composite cathode active material, wherein the composite cathode active material comprises a core, which comprises the first metal oxide, and a coating layer on the core, wherein the coating layer comprises the layered double oxide.

26 . The method of claim 25 , wherein the contacting of the layered double hydroxide and the first metal oxide comprises dry mixing.

27 . The method of claim 25 , wherein the calcining of the mixture is performed at a temperature of 500° C. or greater.

28 . The method of claim 25 , wherein the cal

Assignees

• Samsung Electronics Co Ltd
• Samsung Sdi Co Ltd

Inventors

• Son Youhwan
• Park Seongyong
• Ha Jinsu
• Hong Sukgi
• Park Kwangjin
• Park Junho
• Choi Byungjin

Classifications

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M4/628

  Inhibitors, e.g. gassing inhibitors, corrosion inhibitors · CPC title

• C01P2002/00

  Crystal-structural characteristics · CPC title

• C01G53/42

  containing alkali metals, e.g. LiNiO2 · CPC title

• H01M2004/028

  Positive electrodes · CPC title