Lithium cobalt composite oxide for lithium secondary battery, preparation method thereof, and lithium secondary battery including positive electrode including lithium cobalt composite oxide

Patent metadata

Field	Value
Publication number	US-10090523-B2
Application number	US-201514701328-A
Country	US
Kind code	B2
Filing date	Apr 30, 2015
Priority date	Jun 19, 2014
Publication date	Oct 2, 2018
Grant date	Oct 2, 2018

Abstract

Provided is a lithium cobalt composite oxide for a lithium secondary battery represented by Formula 1 below and having a polycrystalline state, a method of preparing the same, a positive electrode for a lithium battery including the lithium cobalt composite oxide, and a lithium secondary battery including a positive electrode, which includes the lithium cobalt composite oxide.

Li a Co b O c   Formula 1

In Formula 1, a is an integer from 0.9 to 1.1, b is an integer from 0.980 to 1.0000, and c is an integer from 1.9 to 2.1. Also included is a method of manufacture therefor.

First claim

What is claimed is:

1. A lithium cobalt composite oxide for a lithium secondary battery represented by Formula 1:
Li a Co b O c   Formula 1

wherein, a is an integer from 0.9 to 1.1, b is an integer from 0.980 to 1.0000, and c is an integer from 1.9 to 2.1, wherein the lithium cobalt composite oxide is a mixture of primary particles and secondary particles where the secondary particles are polycrystalline and have an uneven surface, and an average diameter of the primary particles is 0.5 μm to 15 μm and an average diameter of the secondary particles is 5 μm to 20μm,
wherein an amount of the secondary particles is about 500 parts by weight to about 1000 parts by weight based on 100 parts by weight of the primary particles; and
wherein the lithium cobalt composite oxide for a lithium secondary battery represented by Formula 1 is made by method comprising:
heat-treating cobalt hydroxide in an oxygen-containing atmosphere at a temperature of 600° C. to 800° C. to obtain cobalt oxide (Co 3 O 4 ), wherein an average diameter of primary particle of the cobalt hydroxide is about 0.1 nm to about 500 nm and an average diameter of primary particle of cobalt oxide is about 500 nm to about 5μm; and
heat-treating a mixture consisting of the cobalt oxide (Co 3 O 4 ) and a lithium precursor at a temperature of 1000° C. to about 1200° C. to obtain the lithium cobalt composite oxide for a lithium secondary battery represented by Formula 1.

2. The lithium cobalt composite oxide of claim 1 , wherein the lithium cobalt composite oxide represented by Formula 1 is LiCoO 2 .

3. The lithium cobalt composite oxide of claim 1 , wherein an amount of the secondary particles is 500 parts by weight to 1000 parts by weight based on 100 parts by weight of the primary particles.

4. The lithium cobalt composite oxide of claim 1 , wherein an average diameter of the lithium cobalt composite oxide primary particles is about 5 μm and an average diameter of the lithium cobalt composite oxide secondary particles is about 15 μm.

5. A positive electrode, which comprises the lithium cobalt composite oxide of claim 1 .

6. A lithium secondary battery comprising a positive electrode, which comprises the lithium cobalt composite oxide of claim 1 .

7. The lithium secondary battery of claim 6 , wherein the lithium cobalt composite oxide represented by Formula 1 is LiCoO 2 .

Assignees

• Samsung Sdi Co Ltd
• Samsung Sdi Co Ltd

Inventors

• Kim Jihyun
• Park Dohyung
• Kwon Seonyoung
• Han Juhyeong
• Kim Jinhwa
• Kim Minhan
• Kim Kyounghyun

Classifications

• C01P2004/61

  Micrometer sized, i.e. from 1-100 micrometer · CPC title

• C01G51/42

  containing alkali metals, e.g. LiCoO2 · CPC title

• C01P2004/51

  Particles with a specific particle size distribution · CPC title

• C01P2006/40

  Electric properties · CPC title

• C01P2004/62

  Submicrometer sized, i.e. from 0.1-1 micrometer · CPC title