Lithium complex oxide for lithium secondary battery positive active material and method of preparing the same

Patent metadata

Field	Value
Publication number	US-10693136-B2
Application number	US-201715459567-A
Country	US
Kind code	B2
Filing date	Mar 15, 2017
Priority date	Jul 11, 2016
Publication date	Jun 23, 2020
Grant date	Jun 23, 2020

Abstract

Disclosed is a lithium complex oxide and method of manufacturing the same, more particularly, a lithium complex oxide effective in improving the characteristics of capacity, resistance, and lifetime with reduced residual lithium and with different interplanar distances of crystalline structure between a primary particle locating in a internal part of secondary particle and a primary particle locating on the surface part of the secondary particle, and a method of preparing the same.

First claim

What is claimed is:

1. A lithium complex oxide secondary particle which is formed by coagulation of a plurality of primary particles and configured to satisfy a relation as follows,
d 1> d 2  <Relation>

wherein
the d1 is an interplanar distance of a crystalline structure in a primary particle locating in the internal part of secondary particle among the plurality of primary particles measured from diffraction patterns, and
the d2 is an interplanar distance of a crystalline structure in a primary particle locating on a surface part of the secondary particle measured from diffraction patterns,

wherein the surface part of the secondary particle has a gradient of concentration of Co ions,
wherein a boundary of the primary particle located in the internal part of secondary particle has a gradient of concentration of Co ions, and
wherein a boundary of the primary particle located on the surface part of the secondary particle has a gradient of concentration of Co ions.

2. The lithium complex oxide secondary particle of claim 1 , wherein the d1, which is the interplanar distance of the crystalline structure in the primary particle locating in the internal part of secondary particle, is configured to be equal to or larger than 4.8 nm to 5.0 nm.

3. The lithium complex oxide secondary particle of claim 1 , wherein the d2, which is the interplanar distance of the crystalline structure in the primary particle locating on the surface part of the secondary particle, is configured to be equal to or smaller than 4.75 nm.

4. The lithium complex oxide secondary particle of claim 1 ,
wherein the lithium complex oxide secondary particle is configured in a hexagonal structure,
wherein a lithium ion pathway is formed toward the center from the surface of the secondary particle.

5. The lithium complex oxide secondary particle of claim 1 , wherein a thickness of the surface part of the secondary particle is 0.3 to 1 μm.

6. The lithium complex oxide secondary particle of claim 1 , wherein the secondary particle has at least one peak at positions (104), (110), (113), (101), (102), and (003) during XRD analysis.

7. The lithium complex oxide secondary particle of claim 1 , wherein the secondary particle has a bound energy (P1) of spin-orbit-spit 2p3/2 peak and a bound energy (P2) of 2p1/2 peak in a Co 2p core-level spectrometry obtained through XPS measurement, and
wherein the P1 and the P2 are ranged in 779 eV≤P1≤780 eV and 794 eV≤P2≤795 eV.

8. The lithium complex oxide secondary particle of claim 1 ,
wherein the secondary particle has a ratio of peak intensity (I 531 ) around 531 eV and peak intensity (I 528 ) around 528.5 eV during an O 1s core-level spectrometry that is obtained through XPS measurement, and
wherein the ratio is I 531 /I 528 ≤2.

9. The lithium complex oxide secondary particle of claim 1 , wherein the secondary particle has a ratio between peak intensity (I 289 ) around 289 eV and peak intensity (I 284 ) around 284.5 eV during a C 1s core-level spectrometry that is obtained through XPS measurement, and
wherein the ratio is I 289 /I 284 ≤0.9.

10. The lithium complex oxide secondary particle of claim 1 , wherein the secondary particle is given by the following Formula 1,
Li X1 Ni 1−(x1+y1+z1) Co x1 M1 y1 M2 z1 M3 r1 O a ,  [Formula 1]

wherein, in the Formula 1,
M1 is Mn or Al, and
M2 and M3 are metals selected from a group of Al, Ba, B, Co, Ce, Cr, F, Li, Mg, Mn, Mo, P, Sr, Ti, and Zr, and
wherein
0.95≤X1≤1.05,
1.50≤a≤2.1,
0.02≤x1≤0.25,
0.01≤y1≤0.20,
0≤z≤0.20, and
0≤r1≤0.20.

11. A method of preparing a lithium complex oxide secondary particle by claim 1 , the method comprising:
manufacturing precursors of a lithium complex oxide secondary particle given by the following Formula 2,
Ni 1−(x2+y2+z2) Co x2 M1 y2 M2 z2 (OH) 2 ,  [Formula 2]

wherein, in Formula 2,
M1 is Mn or Al, and
M2 is a metal selected from a group of Al, Ba, B, Co, Ce, Cr, F, Li, Mg, Mn, Mo, P, Sr, Ti, and Zr, and wherein 0≤x2≤0.25, 0≤y2≤0.20, and 0≤z2≤0.20;

reacting precursors of a lithium complex oxide secondary particle with a lithium compound and manufacturing a positive active material by first thermal treating the reactant;
washing the positive active material with distilled water or an alkaline solution;
reactively coating the washed positive active material with a solution containing M2 that is a metal selected from the group of Al, Ba, B, Co, Ce, Cr, F, Li, Mg, Mn, Mo, P, Sr, Ti, and Zr;
drying particles of the positive active material; and
mixing the dried positive active material with M3 that is a metal selected from the group of Al, Ba, B, Co, Ce, Cr, F, Li, Mg, Mn, Mo, P, Sr, Ti, and Zr and doping the metal M3 into the particles by second thermally treating the mixture.

12. The method of claim 11 , wherein the reactively coating comprises:
reactively coating the washed positive active material with the solution including Co.

13. A lithium secondary battery comprising a lithium complex oxide secondary particle of claim 1 .

14. The lithium secondary battery of claim 13 , wherein the lithium secondary battery is configured to have residual lithium equal to or smaller than 6,000 ppm.

15. A lithium complex oxide secondary particle formed by a method comprising:
manufacturing precursors of a lithium complex oxide secondary particle given by the following Formula 2,
Ni 1−(x2+y2+z2) Co x2 M1 y2 M2 z2 (OH) 2 ,  [Formula 2]

wherein,
M1 is Mn or Al, and
M2 is a metal selected from a group of Al, Ba, B, Co, Ce, Cr, F, Li, Mg, Mn, Mo, P, Sr, Ti, and Zr, and wherein 0≤x2≤0.25, 0≤y2≤0.20, and 0≤z2≤0.20;

reacting precursors of a lithium complex oxide secondary particle with a lithium compound and manufacturing a positive active material by first thermal treating the reactant;
washing the positive active material with distilled water or an alkaline solution;
reactively coating the washed positive active material with a solution containing M2 that is a metal selected from the group of Al, Ba, B, Co, Ce, Cr, F, Li, Mg, Mn, Mo, P, Sr, Ti, and Zr;
drying particles of the positive active material; and
mixing the dried positive active material with M3 that is a metal selected from the group of Al, Ba, B, Co, Ce, Cr, F, Li, Mg, Mn, Mo, P, Sr, Ti, and Zr and doping the metal M3 into the particles by second thermally treating the mixture, and
wherein,
the lithium complex oxide secondary particle is configured to satisfy a relation as follows,
d 1> d 2  <Relation>

wherein,
the d1 is an interplanar distance of a crystalline structure in a primary particle locating in the internal part of secondary particle among the plurality of primary particles measured from diffraction patterns;
the d2 is an interplanar distance of a crystalline structure in a primary particle locating on a surface part of the secondary particle measured from diffraction patterns;
the surface part of the secondary particle has a gradient of concentration of Co ions;
a boundary of the primary particle located in the internal part of secondary particle has a gradient of concentration of Co ions; and
a boundary of the primary particle located on the surface part of the secondary particle has a gradient of concentration of Co ions.

Assignees

• Ecopro Bm Co Ltd

Inventors

• Choi Moon Ho
• Shin Jong Seung
• Kim Dong Hee
• Jeon Suk Yong
• Yu Hyun Jong
• Lee Kyoung Jun
• Park Young Nam

Classifications

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M10/0525

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

• C01G53/42

  containing alkali metals, e.g. LiNiO2 · CPC title

• C01G51/42

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