Positive active material for lithium secondary battery and lithium secondary battery comprising same

Patent metadata

Field	Value
Publication number	US-11901552-B2
Application number	US-201816770248-A
Country	US
Kind code	B2
Filing date	Dec 7, 2018
Priority date	Dec 8, 2017
Publication date	Feb 13, 2024
Grant date	Feb 13, 2024

Abstract

The present disclosure relates to a positive active material for a lithium rechargeable battery and a lithium rechargeable battery including the same, which include a first compound represented by Chemical Formula 1 and a second compound represented by Chemical Formula 2, and a content of the first compound is 65 wt % or more based of the positive active material of 100 wt %.Lia1Nib1Coc1Mnd1M1e1M2f1O2-f1[  Chemical Formula 1]Lia2Nib2COc2Mnd2M3e2M4f2O2-f2[  Chemical Formula 2]Chemical Composition 1 and 2 of each composition and molar ratio is as defined in the specification. Each composition and molar ratio of Chemical Formula 1 and 2 is as defined in the specification.

First claim

What is claimed is:

1. A positive active material for a lithium rechargeable battery, comprising:
a nickel-based lithium metal oxide particle doped with Zr and Al; and
a coating layer disposed on the surface of the nickel-based lithium metal oxide particle,
wherein
the nickel-based lithium metal oxide particle includes
a core portion, and
a shell portion surrounding the core portion and forming a concentration gradient in which a concentration of nickel gradually decreases from an interface with the core portion toward an outer direction,

the coating layer includes an oxyhydroxide of a rare earth element, wherein the rare earth element is cerium (Ce),
the nickel-based lithium metal oxide particle includes:
a first particle having an average particle diameter of 10 μm to 30 μm, and
a second particle having an average particle diameter of 1 μm to 6 μm,

a molar ratio of Zr:Al in the nickel-based lithium metal oxide particles is 10:1 to 2:1.

2. The positive active material for the lithium rechargeable battery of claim 1 , wherein
a primary particle of the nickel-based lithium metal oxide particle has a rod shape with an aspect ratio of 1 or more.

3. The positive active material for the lithium rechargeable battery of claim 1 , wherein
the nickel-based metal oxide particle including the core portion and the shell portion has an average composition represented by Chemical Formula 4 below:
Li m4 [Ni 1-w4-x4-y4-z4 Co w4 M1 x4 M2 y4 M3 z4 ] n4 O 2-p4 X p4   [Chemical Formula 4]

M 1 is one element selected from a group including Mn, Mg, Sn, Ca, Ge, and Ga,
M2 is Zr,
M3 is Al,
X is one element selected from a group including F, N, and P,
w4, x4, y4, z4, and p4 are respectively 0<w4≤0.2, 0<x4≤0.2, 0<y4≤0.006, 0<z4 ≤0.006, 0<w4+x4+y4+z4≤0.4 and 0≤p4≤0.1, 0.95≤m4≤1.1, and 0.95≤n4≤1.1).

4. The positive active material for the lithium rechargeable battery of claim 1 , wherein
a doping amount of Zr in the nickel-based lithium metal oxide particle is 2000 ppm to 5000 ppm.

5. The positive active material for the lithium rechargeable battery of claim 1 , wherein
a doping amount of Al in the nickel-based lithium metal oxide particle is 100 ppm to 1500 ppm.

6. The positive active material for the lithium rechargeable battery of claim 1 , wherein
a molar ratio of Zr:Al in the nickel-based lithium metal oxide particles is 15:1 to 0.4:1.

7. The positive active material for the lithium rechargeable battery of claim 1 , wherein
the composition of the core portion of the nickel-based lithium metal oxide particle is represented by Chemical Formula 5 in the entire region:
Li m5 [Ni 1-w5-x5-y5-z5 Co w5 M1 x5 M2 y5 M3 z5 ] n5 O 2-p5 X p5   [Chemical Formula 5]

(in Chemical Formula 5,
M1 is one element selected from a group including Mn, Mg, Sn, Ca, Ge, and Ga,
M2 is Zr, M3 is Al,
X is one element selected from a group including F, N, and P,
w5, x5, y5, z5, and p5 are respectively 0≤w5≤0.1, 0≤x5≤0.1, 0<y5≤0.005, 0<z5 ≤0.006, 0≤w5+x5+y5+z5≤0.2, and 0<p5<0.1, 0.95≤m5≤1.1, and 0.95≤n5≤1.1).

8. The positive active material for the lithium rechargeable battery of claim 7 , wherein
the composition of the shell portion of the nickel-based lithium metal oxide particle is represented by Chemical Formula 5 in the interface with the core portion, is represented by Chemical Formula 6 at the outermost part of the shell portion, and each molar content of the nickel (Ni), M1, M2, and M3 is gradually changed from the interface to the outermost part:
Li m6 [Ni 1-w6-x6-y6-z6 Co w6 M1 x6 M2 y6 M3 z6 ] n6 O 2-p6 X p6 [  Chemical Formula 6]

(in Chemical Formula 6,
M1 is one element selected from a group including Mn, Mg, Sn, Ca, Ge, and Ga,
M2 is Zr, M3 is Al,
X is one element selected from a group including F, N, and P,
w6, x6, y6, z6, and p6 are respectively 0<w6≤0.3, 0<x6≤0.3, 0<y6≤0.007, 0<z6 ≤0.006, 0<w6+x6+y6+z6≤0.5, and 0≤p6≤0.1, 0.95≤m6≤1.1, and 0.95≤n6≤1.1).

9. The positive active material for the lithium rechargeable battery of claim 1 , wherein
the first particle has an average particle diameter of 12 1μm to 20 μm and
the second particle has an average particle diameter of 41μm to 6 μm.

10. The positive active material for the lithium rechargeable battery of claim 1 , wherein
a mixture weight ratio of the first particle and second particle is 60:40 to 90:10.

11. The positive active material for the lithium rechargeable battery of claim 1 , wherein
the nickel-based lithium metal oxide particle has 50% or more of a value of Equation 3 below:
R 2/( R 2+ D 2)*100%  [Equation 3]

in Equation 3, R2 is a radius of the core portion in the nickel-based metal oxide particle, and D2 is a thickness of the shell portion in the nickel-based metal oxide particle.

12. The positive active material for the lithium rechargeable battery of claim 11 , wherein
the nickel-based lithium metal oxide particle has 75% or more of a value of Equation 3 above.

13. A lithium rechargeable battery comprising:
a negative electrode;
a positive electrode including the positive active material for the lithium rechargeable battery of claim 1 ; and
an electrolyte.

14. The positive active material for the lithium rechargeable battery of claim 1 , wherein
a doping amount of Zr in the nickel-based lithium metal oxide particle is 2200 ppm to 3800 ppm.

15. The positive active material for the lithium rechargeable battery of claim 1 , wherein
a doping amount of Al in the nickel-based lithium metal oxide particle is 120 ppm to 320 ppm.

16. The positive active material for the lithium rechargeable battery of claim 1 , wherein
a mixture weight ratio of the first particle to the second particle is 60:40 to 90:10.

Assignees

• Posco Holdings Inc
• Res Inst Ind Science & Tech
• Posco Future M Co Ltd

Inventors

• Choi Kwon Young
• Park Jong Il
• Nam Sang Cheol
• Lee Sang Hyuk

Classifications

• 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

• H01M4/131

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

• H01M4/366 Primary

  as layered products · CPC title

• H01M4/505

  of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy · CPC title

• H01M10/0525

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