Positive active material for rechargeable lithium battery, method of preparing the same, and rechargeable lithium battery including the same

Patent metadata

Field	Value
Publication number	US-2018123130-A1
Application number	US-201715795550-A
Country	US
Kind code	A1
Filing date	Oct 27, 2017
Priority date	Oct 28, 2016
Publication date	May 3, 2018
Grant date	—

Abstract

A positive active material for a rechargeable lithium battery includes a lithium nickel-based metal oxide represented by Li x Ni 1-y M y O 2 and a lithium-containing oxide on a surface of the lithium nickel-based metal oxide. In the formula Li x Ni 1-y M y O 2 , M is one or more of Co, Mn, Al, Mg, Ti, Zr, or a combination thereof, 0<x<1.1, and 0≤y<0.5.

First claim

What is claimed is:

1 . A positive active material for a rechargeable lithium battery, the positive active material comprising:
a lithium nickel-based metal oxide represented by Chemical Formula 1 and a lithium-containing oxide on a surface of the lithium nickel-based metal oxide:
Li x Ni 1-y M y O 2   (1)

where M is one or more of Co, Mn, Al, Mg, Ti, Zr, or a combination thereof and where 0<x<1.1 and 0≤y<0.5.

2 . The positive active material as claimed in claim 1 , wherein 0.1≤y≤0.4 in Chemical Formula 1.

3 . The positive active material as claimed in claim 1 , wherein Chemical Formula 1 is represented by Chemical Formula 2 or Chemical Formula 3:
Li x Ni 1-a-b CO a Al b O 2   (2)
Li x Ni 1-a-b CO a Mn b O 2   (3)

where 0<x<1.1, 0<a<0.5, 0<b<0.5, and 0<a+b<0.5 in Chemical Formula 2 and Chemical Formula 3.

4 . The positive active material as claimed in claim 1 , wherein the lithium-containing oxide includes at least one of Li 2 O, LiOH, and Li 2 CO 3 .

5 . The positive active material as claimed in claim 1 , wherein the lithium-containing oxide is included in an amount of about 0.01 to about 10 parts by weight based on 100 parts by weight of the lithium nickel-based metal oxide.

6 . The positive active material as claimed in claim 1 , wherein the lithium-containing oxide is a coating layer that coats a part or a whole of the surface of the lithium nickel-based metal oxide.

7 . The positive active material as claimed in claim 6 , wherein the coating layer of the lithium-containing oxide has a rod shape or scale shape.

8 . The positive active material as claimed in claim 6 , wherein the coating layer having a rod shape has an aspect ratio of greater than or equal to about 1.

9 . A method of preparing a positive active material for a rechargeable lithium battery, the method comprising:
mixing a lithium raw material and a nickel-containing metal oxide precursor to prepare a mixture, heat-treating the mixture to prepare a lithium nickel-based metal oxide represented by Chemical Formula 1,
Li x Ni 1-y M y O 2   (1)

where M is one or more of Co, Mn, Al, Mg, Ti, Zr, or a combination thereof and where 0<x<1.1 and 0≤y<0.5, and
dry-mixing the lithium nickel-based metal oxide with a lithium-containing oxide followed by heat treatment.

10 . The method as claimed in claim 9 , wherein y is within a range of 0.1≤y ≤0.4 in Chemical Formula 1.

11 . The method as claimed in claim 9 , wherein the nickel-containing metal oxide precursor is represented by Chemical Formula 4:
Me(OH) 2   (4)

where Me is represented by Chemical Formula 5,
Ni k M 1-k   (5)

where M is one or more of Co, Mn, Al, Mg, Ti, Zr, or a combination thereof and where 0.5<k≤1.0.

12 . The method as claimed in claim 9 , wherein the lithium-containing oxide is Li 2 O LiOH and Li 2 CO 3 includes at least one of Li 2 O, LiOH, and Li 2 CO 3 .

13 . The method as claimed in claim 9 , wherein the lithium-containing oxide is included in an amount of about 0.01 to about 10 parts by weight based on 100 parts by weight of the lithium nickel-based metal oxide.

14 . The method as claimed in claim 9 , wherein the mixture of the lithium raw material and nickel-containing metal oxide precursor is heat-treated at about 600° C. to about 1,000° C.

15 . The method as claimed in claim 9 , wherein a dry-mixture of the lithium nickel-based metal oxide with a lithium-containing oxide is heat-treated at about 400° C. to about 700° C.

16 . A rechargeable lithium battery, comprising:
a positive electrode including a positive active material as claimed in claim 1 , a negative electrode, and an electrolyte solution.

Assignees

• Samsung Sdi Co Ltd

Inventors

• Kim Dongjin
• Kim Minhan
• Park Dohyung
• Park Young Jin
• Kim Kyounghyun
• Kim Ilseok

Classifications

• H01M4/131

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

• C01G53/50

  of the type (MnO2)n-, e.g. Li(NixMn1-x)O2 or Li(MyNixMn1-x-y)O2 · CPC title

• H01M4/1391

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

• C01P2002/50

  Solid solutions · CPC title

• C01P2006/40

  Electric properties · CPC title