Composite cathode active material, cathode and lithium battery comprising the same, and preparation method thereof

Patent metadata

Field	Value
Publication number	US-9979014-B2
Application number	US-201414472190-A
Country	US
Kind code	B2
Filing date	Aug 28, 2014
Priority date	Dec 17, 2013
Publication date	May 22, 2018
Grant date	May 22, 2018

Abstract

A composite cathode active material including a core comprising a lithium compound, and a coating layer formed on at least one portion of the core and including at least two oxide phases having different structures, a cathode and a lithium battery including the same, and a method of preparing the composite cathode active material.

First claim

What is claimed is:

1. A composite cathode active material comprising:
a core comprising a lithium compound; and
a coating layer formed on at least one portion of the core,
wherein the coating layer comprises at least two oxide phases having different structures and a spinel-structured oxide phase and a layer-structured oxide phase, and
wherein an amount of lithium remaining on the surface of the core is less than about 0.20% by weight.

2. The composite cathode active material of claim 1 , wherein the at least two oxide phases having different structures are formed as islands.

3. The composite cathode active material of claim 1 , wherein the coating layer is formed from lithium remaining on a surface of the core and is partially involved in reactions with the at least two oxide phases having different structures.

4. The composite cathode active material of claim 1 , wherein the coating layer comprises at least two oxide phases selected from the group consisting of LiCoO 2 , Li 0.49 CoO 2 , Li 0.5 Co 1.1 O 2 , and Co 3 O 4 .

5. The composite cathode active material of claim 1 , wherein the core comprising the lithium compound is a Li—Ni composite oxide.

6. The composite cathode active material of claim 1 , wherein the core comprising the lithium compound is a Li—Ni composite oxide.

7. The composite cathode active material of claim 1 , wherein the core comprising the lithium compound is a Li—Ni composite oxide.

8. The composite cathode active material of claim 1 , wherein the core comprising the lithium compound is a Li—Ni composite oxide represented by Formula 1 below:
Li a Ni x (M) y O 2   Formula 1

wherein M comprises at least one selected from the group consisting of cobalt (Co), manganese (Mn), chromium (Cr), titanium (Ti), copper (Cu), iron (Fe), aluminum (Al), vanadium (V), and tungsten (W), and
wherein 0.9≤a≤1.2, 0.5≤x≤1.0, and 0≤y≤0.5.

9. The composite cathode active material of claim 1 , wherein the core comprising the lithium compound has an average particle diameter of about 1 μm to about 15 μm.

10. A cathode comprising the composite cathode active material according to claim 1 .

11. A lithium battery comprising:
a cathode comprising a cathode active material;
an anode comprising an anode active material;
an electrolyte interposed between the cathode and the anode,
wherein the cathode active material comprises the composite cathode active material according to claim 1 .

12. The lithium battery of claim 11 , wherein the anode active material is a carbonaceous material.

13. A method of preparing a composite cathode active material, the method comprising:
preparing a core comprising a lithium compound; and
forming a coating layer on at least one portion of the core by applying a transition metal hydroxide to the core, and heat-treating the transition metal hydroxide at about 400° C. or higher,
wherein the coating layer comprises at least two oxide phases having different structures.

14. The method of claim 13 , wherein the preparing of the core comprising the lithium compound comprises heat-treating a precursor comprising a lithium compound at a temperature of from about 800° C. to about 1200° C.

15. The method of claim 13 , wherein the core is a Li—Ni composite oxide represented by Formula 1 below:
LiNi x (M) y O 2   Formula 1

wherein M comprises at least one selected from the group consisting of cobalt (Co), manganese (Mn), chromium (Cr), titanium (Ti), copper (Cu), iron (Fe), aluminum (Al), vanadium (V), and tungsten (W), and
wherein 0.5≤x≤1.0, and 0≤y≤0.5.

16. The method of claim 13 , wherein the transition metal hydroxide comprises Co(OH) 2 .

17. The method of claim 13 , wherein the amount of the transition metal hydroxide is from about 1% by weight to about 10% by weight.

18. The method of claim 13 , wherein the transition metal hydroxide is formed as particles each having an average particle diameter of 1 μm or less.

19. The method of claim 13 , wherein the forming of the coating layer comprises applying the transition metal hydroxide to the core and heat-treating the transition metal hydroxide at a temperature of from about 400° C. to about 900° C.

Assignees

• Samsung Sdi Co Ltd

Inventors

• Kim Min-Han
• Moon Joong-Ho
• Park Han-Eol
• Kim Kyoung-Hyun
• Park Do-Hyung
• Song Yu-Mi
• Hong Ming-Zi
• Kim Jeong-Hoon
• Kim Dong-Jin
• Choi Jeon-Jin
• Jeon Gyu-Ran
• Kang Sun-Ho

Classifications

• H01M2220/30

  Batteries in portable systems, e.g. mobile phone, laptop · CPC title

• H01M4/131

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

• H01M4/1391

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

• H01M4/525

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title

• H01M10/0525

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