Composite cathode active material, method of preparing the same, and cathode and lithium battery including the composite cathode active material

Patent metadata

Field	Value
Publication number	US-2019067689-A1
Application number	US-201816102087-A
Country	US
Kind code	A1
Filing date	Aug 13, 2018
Priority date	Aug 30, 2017
Publication date	Feb 28, 2019
Grant date	—

Abstract

A composite cathode active material including: a secondary particle including a plurality of primary particles including a lithium transition metal oxide having a layered crystal structure; and a coating layer disposed on a surface of the secondary particle and between the primary particles of the plurality of primary particles, wherein the coating layer includes a lithium cobalt composite oxide having a spinel crystal structure, and wherein the lithium cobalt composite oxide includes cobalt (Co) and a Group 2 element, a Group 12 element, a Group 13 element, or a combination thereof.

First claim

What is claimed is:

1 . A composite cathode active material, comprising:
a secondary particle comprising
a plurality of primary particles comprising a lithium transition metal oxide having a layered crystal structure; and
a coating layer disposed on a surface of the secondary particle and between primary particles of the plurality of primary particles,
wherein the coating layer comprises a lithium cobalt composite oxide having a spinel crystal structure, and
wherein the lithium cobalt composite oxide comprises cobalt, and a Group 2 element, a Group 12 element, a Group 13 element, or a combination thereof.

2 . The composite cathode active material of claim 1 , wherein the coating layer is present in a grain boundary between adjacent primary particles of the plurality of primary particles, and on the surface of the secondary particle.

3 . The composite cathode active material of claim 1 , wherein the lithium cobalt composite oxide having a spinel crystal structure comprises a compound represented by Formula 1:
Li x Co a Me b O 4+δ   Formula 1
wherein, in Formula 1, Me is a Group 2 element, a Group 12 element, a Group 13 element, or a combination thereof, and wherein 1.0≤x≤1.1, 0<a<2, 0<b<2, 0<a+b≤2, and −1.5≤δ≤0.

4 . The composite cathode active material of claim 3 , wherein Me in Formula 1 is Al, Ga, Mg, Ca, Ba, Zn, or a combination thereof.

5 . The composite cathode active material of claim 1 , wherein the lithium cobalt composite oxide having a spinel crystal structure is Li x Co a Al b O 4+δ , Li x Co a Zn b O 4+δ , Li x LiCo a Mg b O 4+δ , Li x Co a Ga b O 4+δ , Li x Co a Ca b O 4+δ , or Li x Co a Ba b O 4+δ , wherein 1.0≤x≤1.1, 0<a<2, 0<b<2, 0<a+b≤2, and −1.5≤δ≤0.

6 . The composite cathode active material of claim 1 , wherein the lithium cobalt composite oxide having a spinel crystal structure is LiCo 1.5 Al 0.5 O 4+δ wherein −0.5≤δ≤0, LiCo 1.5 Ga 0.5 O 4+δ wherein −0.5≤δ≤0, LiCo 1.33 Zn 0.67 O 4+δ wherein −0.835≤δ≤0, LiCo 1.33 Ca 0.67 O 4+δ wherein −0.835≤δ≤0, LiCo 1.33 Ba 0.67 O 4+δ wherein −0.835≤δ≤0, LiCo 1.33 Ga 0.67 O 4+δ wherein −0.835≤δ≤0, LiCo 1.2 Mg 0.8 O 4+δ wherein −0.9≤δ≤0, LiCo 1.2 Ga 0.8 O 4+δ wherein −0.9≤δ≤0, LiCo 1.2 Ca 0.8 O 4+δ wherein −0.9≤δ≤0, LiCo 1.2 Ba 0.8 O 4+δ wherein −0.9≤δ≤0, LiCo 1.2 Zn 0.8 O 4+δ wherein −0.9≤δ≤0, LiCo 1.6 Mg 0.4 O 4+δ wherein −0.7≤δ≤0, LiCo 1.6 Ga 0.4 O 4+δ wherein −0.7≤δ≤0, LiCo 1.6 Ca 0.4 O 4+δ wherein −0.7≤δ≤0, LiCo 1.6 Ba 0.4 O 4+δ wherein −0.7≤δ≤0, LiCo 1.6 Zn 0.4 O 4+δ wherein −0.7≤δ≤0, LiCo 0.8 Mg 1.2 O 4+δ wherein −1.1≤δ≤0, LiCo 0.8 Ga 1.2 O 4+δ wherein −1.1≤δ≤0, LiCo 0.8 Ca 1.2 O 4+δ wherein −1.1≤δ≤0, LiCo 0.8 Ba 1.2 O 4+δ wherein −1.1≤δ≤0, LiCo 0.8 Zn 1.2 O 4+δ wherein −1.1≤δ≤0, LiCo 0.4 Mg 1.6 O 4+δ wherein −1.3≤δ≤0, LiCo 0.4 Ga 1.6 O 4+δ wherein −1.3≤δ≤0, LiCo 0.4 Ca 1.6 O 4+δ wherein −1.3≤δ≤0, LiCo 0.4 Ba 1.6 O 4+δ wherein −1.3≤δ≤0, or LiCo 0.4 Zn 1.6 O 4+δ wherein −1.3≤δ≤0.

7 . The composite cathode active material of claim 1 , wherein the lithium transition metal oxide having a layered crystal structure has a rock-salt layered structure and belongs to space group R-3m, and
wherein the lithium cobalt composite oxide belongs to space group Fd-3m.

8 . The composite cathode active material of claim 1 , further comprising a mixed phase between the lithium transition metal oxide and the coating layer, wherein the mixed phase comprises a combination of the lithium transition metal oxide and the lithium cobalt composite oxide.

9 . The composite cathode active material of claim 1 , further comprising, between the primary particles, a compound having an amorphous structure, a compound having a layered crystal structure, or a combination thereof.

10 . The composite cathode active material of claim 1 , wherein the lithium transition metal oxide having a layered crystal structure comprises at least one compound represented by Formulae 2 to 4:
Li x Co 1-y M y O 2-α X α ,  Formula 2
Li x Ni 1-y Me y O 2-α X α , and  Formula 3
Li x Ni 1-y-z Mn y Ma z O 2-α X α ,  Formula 4
wherein, in Formulae 2 to 4, 0.95≤x≤1.1, 0≤y≤0.9, 0<z≤0.2, and 0≤α≤2, M is Ni, Mn, Zr, Al, Mg, Ag, Mo, Ti, V, Cr, Fe, Cu, B, or a combination thereof, Me is Co, Zr, Al, Mg, Ag, Mo, Ti, V, Cr, Mn, Fe, Cu, B, or a combination thereof, Ma is Co, Zr, Al, Mg, Ag, Mo, Ti, V, Cr, Fe, Cu, B, or a combination thereof, and X is F, S, P, or a combination thereof.

11 . The composite cathode active material of claim 1 , wherein the lithium transition metal oxide having a layered crystal structure comprises at least one compound represented by Formulae 5 to 7:
Li[Li 1-a Me a ]O 2+d ,  Formula 5
wherein, in Formula 5, 0.85≤a<1, and 0≤d≤0.1, and Me is Ni, Co, Mn, Al, V, Cr, Fe, Zr, Re, B, Ge, Ru, Sn, Ti, Nb, Mo, Pt, or a combination thereof,
Li[Li 1-x-y-z Ma x Mb y Mc z ]O 2+d ,  Formula 6

wherein, in Formula 6, 0.8≤x+y+z<1, 0<x<1, 0<y<1, 0<z<1, and 0≤d≤0.1, and Ma, Mb, and Mc are each independently Mn, Co, Ni, or Al,
Li[Li 1-x-y-z Ni x Co y Mn z ]O 2+d ,  Formula 7

wherein, in Formula 7, 0.8≤x+y+z<1, 0<x<1, 0<y<1, 0<z<1, and 0≤d≤0.1.

12 . The composite cathode active material of claim 1 , wherein the lithium transition metal oxide is represented by Formula 8:
a Li 2 MnO 3- (1− a )LiMO 2   Formula 8
wherein, in Formula 8, 0<a<1; and M is nickel and cobalt, manganese, vanadium, chrome, iron, zirconium, rhenium, aluminum, boron, germanium, ruthenium, tin, titanium, niobium, molybdenum, platinum, or a combination thereof.

13 . The composite cathode active material of claim 1 , wherein the lithium transition metal oxide having a layered crystal structure is represented by Formula 9:
Li x Ni 1-y-z M y Co z O 2   Formula 9
wherein, in Formula 9, 0.90≤x≤1.1, 0≤y≤0.2, 0<z≤0.2, and 0.7≤1−y−z≤0.99; and M is manganese, aluminum, titanium, calcium, or a combination thereof.

14 . The composite cathode active material of claim 1 , wherein an average particle diameter of the secondary particle is about 10 micrometers to about 20 micrometers.

15 . The composite cathode active material of claim 1 , wherein the lithium transition metal oxide having a layered crystal structure is a compound represented by Formula 9a:
Li x Ni 1-y-z Mn x Co y O 2   Formula 9a
wherein, in Formula 9a, 0.80≤x≤1.1, 0=y≤0.2, 0<z≤0.2, and 0.8≤1−y−z≤0.99.

16 . The composite cathode active material of claim 1 , wherein the nickel containing lithium transition metal oxide having a layered crystal structure is Li 1.03 [Ni 0.91 Co 0.06 Mn 0.03 ]O 2 , Li 1.03 [Ni 0.88 Co 0.08 Mn 0.04 ]O 2 , Li 1.03 [Ni 0.85 Co 0.15 Mn 0.05 ]O 2 , Li 1.03 [Ni 0.85 Co 0.10 Mn 0.05 ]O 2 , Li 1.03 [Ni 0.91 Co 0.05 Mn 0.04 ]O 2 , Li 1.05 [Ni 0.91 Co 0.06 Mn 0.03 ]O 2 , Li 1.06 [Ni 0.91 Co 0.06 Mn 0.03 ]O 2 , Li 1.06 [Ni 0.88 Co 0.08 Mn 0.04 ]O 2 , Li 1.06 [Ni 0.8 Co 0.15 Mn 0.05 ]O 2 , Li 1.06 [Ni 0.85 Co 0.10 Mn 0.05 ]O 2 , Li 1.06 [Ni 0.91 Co 0.05 Mn 0.04 ]O 2 , Li 1.09 [Ni 0.91 Co 0.06 Mn 0.03 ]O 2 , Li 1.09 [Ni 0.88 Co 0.08 Mn 0.04 ]O 2 , Li 1.09 [Ni 0.8 Co 0.15 Mn 0.05 ]O 2 , Li 1.09 [Ni 0.85 Co 0.10 Mn 0.05 ]O 2 , or Li 1.09 [Ni 0.91 Co 0.05 Mn 0.04 ]O 2 .

17 . The composite cathode active material of claim 1 , wherein an amount of the lithium cobalt composite oxide or a total amount of cobalt and metal (M) in the coating layer is about 0.01 parts to about 20 parts by weight, based on 100 parts by weight of the lithium transition metal oxide having a layered crystal structure.

18 . The composite cathode active material of claim 1 , wherein a residual lithium content of the composite cathode act

Assignees

• Samsung Electronics Co Ltd
• Samsung Sdi Co Ltd

Inventors

• Hong Sukgi
• Son Youhwan
• Yu Byongyong
• Park Kwangjin
• Park Junho
• Park Jinhwan
• Choi Byungjin

Classifications

• H01M4/485

  of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence) · CPC title

• H01M10/0525

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

• H01M2004/021

  Physical characteristics, e.g. porosity, surface area · 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

• H01M4/0471

  involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis · CPC title