POSITIVE ACTIVE MATERIAL, POSITIVE ELECTRODE AND LITHIUM BATTERY INCLUDING THE POSITIVE ACTIVE MATERIAL, AND METHOD OF MANUFACTURING THE POSITIVE ACTIVE MATERIAL

• US 20150228971A1
• Filed: 12/24/2014
• Published: 08/13/2015
• Est. Priority Date: 02/07/2014
• Status: Active Grant

• Current Assignee: Samsung SDI Company Limited
• Original Assignee: Samsung SDI Company Limited
• Inventors: Kim, Ji-Hyun, Kim, Chang-Wook, You, Yong-Chan, Je, Hyun-Joo
• Granted Patent: US 9,570,738 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 2220/20 Batteries in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H01M 2220/30 Batteries in portable systems, e.g. mobile phone, laptop
• CPC Class Codes: H01M 4/0402 Methods of deposition of the material
• CPC Class Codes: H01M 4/0471 involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis
• CPC Class Codes: H01M 4/13 Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
• CPC Class Codes: H01M 4/139 Processes of manufacture
• CPC Class Codes: H01M 4/1391 of 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 4/485 of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy H01M4/505, H01M4/525 take precedence
• 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

Abstract

A positive active material, a positive electrode and a lithium battery containing the positive active material, and a method of manufacturing the positive active material are disclosed. The positive active material includes: a positive active material core particle for intercalating and deintercalating lithium ions; and a coating layer at least partially surrounding the positive active material core particle and including a ceramic composite represented by Formula 1.

Li_7+aLa_3−bZr_2−cM_dO_12+e  Formula 1

In Formula 1, M comprises at least one selected from aluminum (Al), titanium (Ti), scandium (Sc), vanadium (V), yttrium (Y), niobium (Nb), hafnium (Hf), tantalum (Ta), silicon (Si), gallium (Ga), and germanium (Ge), and −1≦a≦1, 0≦b≦2, 0≦c≦2, 0≦d≦2, and 0≦e≦1.

Claims

1. A positive active material comprising:

a positive active material core particle for intercalating and deintercalating lithium ions; and

a coating layer at least partially surrounding the positive active material core particle and comprising a ceramic composite represented by Formula 1;

Li_7+aLa<sub>3−

b</sub>Zr<sub>2−

c</sub>M_dO_12+e 

 

Formula 1

wherein M comprises at least one selected from aluminum (Al), titanium (Ti), scandium (Sc), vanadium (V), yttrium (Y), niobium (Nb), hafnium (Hf), tantalum (Ta), silicon (Si), gallium (Ga), and germanium (Ge), and

−

1≦

a≦

1, 0≦

b≦

2, 0≦

c≦

2, 0<

d≦

2, and 0≦

e≦

1.

2. The positive active material of claim 1, wherein the ceramic composite is represented by Formula 2:

Li_7+a′

La<sub>3−

b′</sub>

Zr<sub>2−

c′</sub>

M_d′

O_12+e′

 

 

Formula 2

wherein M comprises at least one selected from Al, Ti, Sc, V, Y, Nb, Hf, Ta, Si, Ga, and Ge, and

−

0.5≦

a′

≦

0.5, 0≦

b′

≦

1, 0≦

c′

≦

1, 0≦

d′

≦

1, and 0≦

e′

≦

0.5.

3. The positive active material of claim 1, wherein the ceramic composite is represented by Formula 3:

Li₇La<sub>3−

b″</sub>

Zr₂Al_d″

O₁₂ 

 

Formula 3

wherein 0<

b″

≦

2 and 0<

d″

≦

2.

4. The positive active material of claim 1, wherein the ceramic composite is represented by Formula 4:

Li₇La₃Zr<sub>2−

c′

″</sub>

Ti<sub>d′

″</sub>

O₁₂ 

 

Formula 4

wherein 0<

c′

″

<

2 and 0<

d′

″

<

2.

5. The positive active material of claim 1, wherein the ceramic composite is represented by Formula 5:

Li₇La<sub>3−

x</sub>Al_xZr<sub>2−

y</sub>Ti_yO₁₂ 

 

Formula 5

wherein 0≦

x≦

2, 0≦

y≦

2, and 0<

x+y≦

2.

6. The positive active material of claim 1, wherein the coating layer is discontinuous.

7. The positive active material of claim 1, wherein the coating layer comprises coating particles comprising the ceramic composite.

8. The positive active material of claim 7, wherein the coating particles have an average particle diameter in a range of about 100 nm to about 1,000 nm.

9. The positive active material of claim 1, wherein the coating layer has a thickness in a range of about 100 nm to about 1,000 nm.

10. The positive active material of claim 1, wherein the positive active material core particle comprises at least one selected from LiCoO₂;

LiNiO;

LiMnO₂;

LiMn₂O₄;

Li(Ni_aCo_bMn_c)O₂, wherein 0<

a<

1, 0<

b<

1, 0<

c<

1, a+b+c=1;

LiNi<sub>1−

y</sub>Co_yO₂, wherein 0≦

y<

1;

LiCo<sub>1−

y</sub>Mn_yO₂, wherein 0≦

y<

1;

LiNi<sub>1−

y</sub>Mn_yO₂, wherein 0≦

y<

1;

LiMn<sub>2−

z</sub>Ni_zO₄, wherein 0<

z<

2;

LiMn<sub>2−

z</sub>Co_zO₄, wherein 0<

z<

2;

V₂O₅;

TiS; and

MoS.

11. The positive active material of claim 1, wherein the positive active material has an operating potential in a range of about 4.0 V to about 5.5 V.

12. The positive active material of claim 1, wherein the positive active material core particle has an average particle diameter in a range of about 1 μ

m to about 30 μ

m.

13. The positive active material of claim 1, wherein the coating layer is present in the positive active material at a mole ratio in a range of about 0.05 to about 5 mol % based on 1 mole of the positive active material core particle.

14. A lithium battery comprising the positive active material of claim 1.

15. A method of manufacturing a positive active material, the method comprising:

preparing a mixed solution comprising a lanthanum (La) precursor, a zirconium (Zr) precursor, and an additive metal M, wherein M comprises at least one selected from Al, Ti, Sc, V, Y, Nb, Hf, Ta, Si, Ga, and Ge;

adding a weak acid comprising citric acid, lactic acid, acetic acid, formic acid, oxalic acid, uric acid, or a mixture thereof, to the mixed solution to prepare a coating solution;

applying a coating of the coating solution onto a surface of a positive active material core particle capable of intercalating and deintercalating lithium ions; and

heat-treating the coating to prepare the positive active material.

16. The method of claim 15, wherein the positive active material core particle capable of intercalating and deintercalating lithium ions comprises a lithium transition metal oxide.

17. The method of claim 15, wherein the coating solution further comprises a dispersing agent comprising isopropyl alcohol (IPA), n-butyl alcohol, terpineol, sodium hexametaphosphate, or a mixture thereof.

18. The method of claim 15, wherein the coating solution further comprises a solvent, and the method further comprises evaporating the solvent from the coating solution before the applying of the coating of the coating solution onto the surface of the positive active material core particle capable of intercalating and deintercalating lithium ions.

19. The method of claim 15, further comprising drying the coating of the coating solution at a temperature in a range of about 100°

C. to about 300°

C. between the applying of the coating of the coating solution onto the surface of the positive active material core particle capable of intercalating and deintercalating lithium ions and the heat-treating.

20. The method of claim 15, wherein the heat-treating is performed at a temperature in a range of about 600°

C. to about 1,000°

C.