Positive active material, positive electrode and lithium battery including the positive active material, and method of manufacturing the positive active material

Patent metadata

Field	Value
Publication number	US-9570738-B2
Application number	US-201414582964-A
Country	US
Kind code	B2
Filing date	Dec 24, 2014
Priority date	Feb 7, 2014
Publication date	Feb 14, 2017
Grant date	Feb 14, 2017

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+a La 3−b Zr 2−c M d O 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.

First claim

What is claimed is:

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+a La 3−b Zr 2−c M d O 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 3−b′ Zr 2−c′ 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:
Li 7 La 3−b″ Zr 2 Al d″ O 12   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:
Li 7 La 3 Zr 2−c′″ Ti d′″ O 12   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:
Li 7 La 3−x Al x Zr 2−y Ti y O 12   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 LiCoO 2 ; LiNiO; LiMnO 2 ; LiMn 2 O 4 ; Li(Ni a Co b Mn c )O 2 , wherein 0<a<1, 0<b<1, 0<c<1, a+b+c=1; LiNi 1−y Co y O 2 , wherein 0≦y<1; LiCo 1−y Mn y O 2 , wherein 0≦y<1; LiNi 1−y Mn y O 2 , wherein 0≦y<1; LiMn 2−z Ni z O 4 , wherein 0<z<2; LiMn 2−z Co z O 4 , wherein 0<z<2; V 2 O 5 ; 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 μm to about 30 μm.

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 according to claime 1 , 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.

Assignees

• Samsung Sdi Co Ltd

Inventors

• Kim Ji-Hyun
• Je Hyun-Joo
• Kim Chang-Wook
• You Yong-Chan

Classifications

• H01M4/366 Primary

  as layered products · CPC title

• H01M4/139

  Processes of manufacture · CPC title

• H01M4/505

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

• H01M4/0471

  involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis · CPC title

• H01M4/485

  of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence) · CPC title