POSITIVE ACTIVE MATERIAL COMPOSITION FOR LITHIUM BATTERY, METHOD OF PREPARING THE SAME, AND LITHIUM BATTERY INCLUDING THE SAME

• US 20150010824A1
• Filed: 09/22/2014
• Published: 01/08/2015
• Est. Priority Date: 03/30/2006
• Status: Active Grant

• Current Assignee: Industry-University Cooperation Foundation Hanyang University
• Original Assignee: Industry-University Cooperation Foundation Hanyang University
• Inventors: SUN, Yang-Kook, PARK, Byung-Chun
• Granted Patent: US 10,367,197 B2
• Time in Patent Office: Days
• US Class Current: 429/223
• CPC Class Codes: C01G 53/50 of the type [MnO2]n- , e.g. Li(NixMn1-x)O2, Li(MyNixMn1-x-y)O2
• CPC Class Codes: C01P 2002/52 containing elements as dopants
• CPC Class Codes: C01P 2002/72 by d-values or two theta-values, e.g. as X-ray diagram
• CPC Class Codes: C01P 2002/88 by thermal analysis data, e.g. TGA, DTA, DSC
• CPC Class Codes: C01P 2004/03 obtained by SEM
• CPC Class Codes: C01P 2004/32 Spheres
• CPC Class Codes: C01P 2006/40 Electric properties
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 2004/021 Physical characteristics, e.g. porosity, surface area
• CPC Class Codes: H01M 4/131 Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• CPC Class Codes: H01M 4/366 as layered products
• CPC Class Codes: H01M 4/505 of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
• CPC Class Codes: H01M 4/525 of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

The present invention relates to a positive active material for a lithium battery, a method of preparing the same, and a lithium battery including the same. More particularly, the present invention relates to a positive active material having excellent high-capacity and thermal stability, a method of preparing the same, and a lithium battery including the same.

Claims

1. A positive active material for a lithium battery comprising:

an internal bulk part including at least two of nickel, manganese, or cobalt; and

an external bulk part surrounding the internal bulk part,

wherein,

at least one metal element is distributed in a continuous concentration gradient from an interface between the internal bulk part and the external bulk part to a surface of the positive active material, and

a concentration change rate of the at least one metal element from the interface to the surface of the positive active material is in a range of 0.1 mol %/0.1 μ

m to 50 mol %/0.1 μ

m.

2. The positive active material of claim 1, wherein the concentration change rate of at least one metal element from the interface to the surface of the positive active material is in a range of 0.1 mol %/0.1 μ

m to 20 mol %/0.1 μ

m.

3. The positive active material of claim 1,

wherein

the internal bulk part includes nickel and cobalt;

the concentration change rate of nickel in the external bulk part is in a range of 2 mol %/0.1 μ

m to 20 mol %/0.1 μ

m, and

the concentration change rate of cobalt in the external bulk part is in a range of 0.1 mol %/0.1 μ

m to 10 mol %/0.1 μ

m.

4. The positive active material of claim 3, further comprising manganese in the internal bulk part, wherein the concentration change rate of nickel, the concentration change rate of cobalt, and a concentration change rate of manganese in the external bulk part satisfy the following relation formulas 1 and 2:

M_Ni≧

M_Co 

 

[Relation formula 1]

M_Ni≧

M_Mn and 

 

[Relation formula 2]

wherein “

M_Ni”

is the concentration change rate of nickel, “

M_Co”

is the concentration change rate of cobalt, and “

M_Mn”

is the concentration change rate of manganese.

5. The positive active material of claim 1, wherein a concentration of a metal in a surface portion of the external bulk part is at least 5% more than a concentration of the metal in the internal bulk part.

6. The positive active material of claim 1, wherein the internal bulk part includes a high-capacity compound including nickel, cobalt, and manganese, and the external bulk part includes a compound including nickel and manganese and having excellent thermal stability.

7. The positive active material of claim 1, wherein the internal bulk part includes a lithium-containing compound expressed by the following chemical formula 1,

wherein the external bulk part includes one selected from a group consisting of a material expressed by the following chemical formula 2, a material expressed by the following chemical formula 3, and a mixture thereof,

Li_aNi₁₋

x−

y−

zCo_xMn_yM_zO<sub>2−

δ</sub>

X_δ

 

 

[Chemical formula 1]

wherein, in the chemical formula 1, 0.95≦

a≦

1.2, 0.01≦

x≦

0.5, 0.01≦

y≦

0.5, 0.005≦

z≦

0.3, 0.05≦

x+y+z≦

0.4, “

M”

is at least one element selected from a group consisting of Mg, Al, Cr, V, Ti, Cr, Fe, Zr, Zn, Si, Y, Nb, Ga, Sn, Mo, W, and combinations thereof, “

X”

is a halogen of F, Cl, Br, or I, and 0≦

δ

≦

0.1,

Li_aNi<sub>1−

x−

y−

z</sub>Co_xMn_yM_zO<sub>2−

δ</sub>

X_δ

 

 

[Chemical formula 2]

wherein, in the chemical formula 2, 0.95≦

a≦

1.2, 0.01≦

x≦

0.4, 0.01≦

y≦

0.5, 0.002≦

z≦

0.2, 0.4<

x+y+z≦

0.95, “

M”

is at least one element selected from a group consisting of Mg, Al, Cr, V, Ti, Cr, Fe, Zr, Zn, Si, Y, Nb, Ga, Sn, Mo, W, and combinations thereof, “

X”

is a halogen of F, Cl, Br, or I, and 0≦

δ

≦

0.1, and

Li_aNi_xCo<sub>1−

2x</sub>Mn<sub>x−

y</sub>M_yO<sub>2−

δ</sub>

X_δ

 

 

[Chemical formula 3]

wherein, in the chemical formula 3, 0.95≦

a≦

1.2, 0.01≦

x≦

0.5, 0≦

y≦

0.1, “

M”

is at least one element selected from the group consisting of Mg, Al, Cr, V, Ti, Cr, Fe, Zr, Zn, Si, Y, Nb, Ga, Sn, Mo, W, and combinations thereof, “

X”

is a halogen of F, Cl, Br, or I, and 0≦

δ

≦

0.1.

8. The positive active material of claim 1, wherein an average particle diameter of the internal bulk part is in a range of 4 μ

m to 15 μ

m, and an average particle diameter of particles of the positive active material is in a range of 9 μ

m to 30 μ

m.