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

Patent metadata

Field	Value
Publication number	US-2022255072-A1
Application number	US-202117454209-A
Country	US
Kind code	A1
Filing date	Nov 9, 2021
Priority date	Jan 29, 2021
Publication date	Aug 11, 2022
Grant date	—

Abstract

A positive active material for a rechargeable lithium battery includes a lithium nickel-based metal composite oxide, wherein the positive active material includes secondary particles in which a plurality of primary particles are aggregated, a first boron coating portion present on the outer surfaces of the secondary particles, and a second boron coating portion present on surfaces of the primary particles inside the secondary particles, and a weight of the first boron coating portion is greater than a weight of the second boron coating portion.

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 composite oxide,
wherein the positive active material comprises:
a secondary particle, in which a plurality of primary particles are aggregated,
a first boron coating portion on an outer surface of the secondary particle, and
a second boron coating portion on surfaces of the primary particles inside the secondary particle, and
wherein a weight of the first boron coating portion is greater than a weight of the second boron coating portion.

2 . The positive active material of claim 1 , wherein the first boron coating portion and the second boron coating portion each comprise boron oxide, lithium boron oxide, or a combination thereof.

3 . The positive active material of claim 1 , wherein the first boron coating portion is comprised in an amount of about 70 wt % to about 98 wt % and the second boron coating portion is comprised in an amount of about 2 wt % to about 30 wt %, each based on a total amount of the first boron coating portion and the second boron coating portion.

4 . The positive active material of claim 3 , wherein the first boron coating portion is comprised in an amount of about 80 wt % to about 95 wt % and the second boron coating portion is comprised in an amount of about 5 wt % to about 20 wt %, each based on a total amount of the first boron coating portion and the second boron coating portion.

5 . The positive active material of claim 1 , wherein a content of the first boron coating portion is about 200 ppm to about 5000 ppm based on the positive active material.

6 . The positive active material of claim 1 , wherein a content of the second boron coating portion is about 10 ppm to about 500 ppm based on the positive active material.

7 . The positive active material of claim 1 , wherein a total amount of the first boron coating portion and the second boron coating portion is about 0.1 mol % to about 5 mol % based on 100 mol % of the positive active material.

8 . The positive active material of claim 7 , wherein a total amount of the first boron coating portion and the second boron coating portion is about 0.1 mol % to about 1.3 mol % based on 100 mol % of the positive active material.

9 . The positive active material of claim 1 , wherein in the lithium nickel-based metal composite oxide, a content of nickel is greater than or equal to about 60 mol % based on 100 mol % of the lithium nickel-based metal composite oxide.

10 . The positive active material of claim 1 , wherein the lithium nickel-based metal composite oxide is represented by Chemical Formula 1:
Li a1 Ni x1 M 1 y1 M 2 1-x1-y1 O 2 , and  Chemical Formula 1
wherein, in Chemical Formula 1, 0.9≤a1≤1.8, 0.6≤x1≤1, 0≤y1≤0.4, and M 1 and M 2 are each independently selected from Al, B, Ba, Ca, Ce, Co, Cr, Cu, F, Fe, Mg, Mn, Mo, Nb, P, S, Si, Sr, Ti, V, W, Zr, and combinations thereof.

11 . The positive active material of claim 1 , wherein the lithium nickel-based metal composite oxide is represented by Chemical Formula 2 or Chemical Formula 3:
Li a2 Ni x2 Co y2 Al z2 M 3 1-x2-y2-z2 O 2 ,  Chemical Formula 2
wherein, in Chemical Formula 2, 0.9≤a2≤1.8, 0.6≤x2<1, 0<y2<0.4, 0<z2<0.4, and M 3 is selected from B, Ba, Ca, Ce, Co, Cr, Cu, F, Fe, Mg, Mn, Mo, Nb, P, S, Si, Sr, Ti, V, W, Zr, and combinations thereof,
Li a3 Ni x3 Co y3 M 4 1-x3-y3 O 2 , and  Chemical Formula 3

wherein, in Chemical Formula 3, 0.9≤a3≤1.8, 0.6≤x3<1, 0<y3≤0.4, and M 4 is selected from B, Ba, Ca, Ce, Co, Cr, Cu, F, Fe, Mg, Mn, Mo, Nb, P, S, Si, Sr, Ti, V, W, Zr, and a combination thereof.

12 . A method of preparing the positive active material of claim 1 , the method comprising:
mixing a nickel-based metal composite hydroxide, a lithium raw material and a boron raw material to obtain a mixture, and heat-treating the mixture.

13 . The method of claim 12 , wherein a content of the boron raw material is about 0.1 mol % to about 5 mol % based on 100 mol % of the nickel-based metal composite hydroxide.

14 . The method of claim 12 , wherein the heat-treating of the mixture is performed at a temperature of about 650° C. to about 850° C.

15 . The method of claim 12 , wherein the heat-treating of the mixture is performed for about 5 hours to about 15 hours.

16 . A rechargeable lithium battery, comprising:
a positive electrode comprising the positive active material of claim 1 , a negative electrode, and an electrolyte.

Assignees

• Samsung Sdi Co Ltd

Inventors

• Yun Pilsang
• Kim Hyunbeom
• Park Sangin
• You Yongchan

Classifications

• H01M4/366

  as layered products · CPC title

• H01M4/525 Primary

  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

• H01M4/362 Primary

  Composites · CPC title

• H01M4/48

  of inorganic oxides or hydroxides · CPC title