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

Patent metadata

Field	Value
Publication number	US-2024258501-A1
Application number	US-202118008934-A
Country	US
Kind code	A1
Filing date	Jun 11, 2021
Priority date	Jun 11, 2021
Publication date	Aug 1, 2024
Grant date	—

Abstract

Provided are a positive active material for a rechargeable lithium battery including a single particle including a lithium nickel-based composite oxide, and a coating portion disposed on a surface of the single particle and containing S and Si, a preparing method thereof, and a rechargeable lithium battery including the same.

First claim

1 . A positive active material for a rechargeable lithium battery, comprising
a single particle including a lithium nickel-based composite oxide, and a coating portion disposed on a surface of the single particle and containing S and Si.

2 . The positive active material for the rechargeable lithium battery of claim 1 , wherein
the coating portion includes a sulfur-containing compound represented by Chemical Formula 1 and a silicon-containing compound represented by Chemical Formula 2:

wherein, in Chemical Formula 1, A is an alkali metal, 0≤a1≤2, and 0≤z1≤4, and

wherein, in Chemical Formula 2, A is an alkali metal, 0≤a2≤5, 1≤x2≤2, and 0≤z2≤4.

3 . The positive active material for the rechargeable lithium battery of claim 2 , wherein
the silicon-containing compound represented by Chemical Formula 2 is distributed on the surface of the single particle, and it exists in the form of an island having a thickness of 1 nm to 50 nm, and/or is present in a crack portion inside the single particle.

4 . The positive active material for the rechargeable lithium battery of claim 1 , wherein
the coating portion includes a sulfur-silicon-containing compound represented by Chemical Formula 3:

wherein, in Chemical Formula 3, A is an alkali metal, 0≤a3≤5, 0<x3≤2, 0<y3≤5, and 0≤z3≤10.

5 . The positive active material for the rechargeable lithium battery of claim 1 , wherein
the coating portion includes at least one of a sulfur-containing compound represented by Chemical Formula 1-1 and a silicon-containing compound represented by Chemical Formula 2-1:

wherein, in Chemical Formula 1-1, A is an alkali metal, 0≤a1≤2, 0≤z1≤4, and 0≤n1≤5,

wherein, in Chemical Formula 2-1, A is an alkali metal, 0≤a2≤2, 1≤x2≤2, 0≤z2≤4, and 0≤n2≤5.

6 . The positive active material for the rechargeable lithium battery of claim 1 , wherein
the coating portion includes a sulfur-silicon-containing compound represented by Chemical Formula 3-1:

wherein, in Chemical Formula 3-1, A is an alkali metal, 0≤a3≤5, 0<x3≤2, 0<y3≤5, 0≤z3≤10, and 0≤n3≤5.

7 . The positive active material for the rechargeable lithium battery of claim 1 , wherein
the coating portion further includes at least one element selected from P, Co, and Zr.

8 . The positive active material for the rechargeable lithium battery of claim 1 , wherein
the coating portion further includes a phosphorus-containing compound represented by Chemical Formula 4:

wherein, in Chemical Formula 4, A is an alkali metal, 0≤a4≤3, and 0≤z4≤4.

9 . The positive active material for the rechargeable lithium battery of claim 1 , wherein
the lithium nickel-based composite oxide is represented by Chemical Formula 11:

wherein, in Chemical Formula 11, 0.9≤a11≤1.8, 0.6≤x11≤1, 0≤y11≤0.4, and M 1 and M 2 are each independently selected from Al, B, Ce, Co, Cr, F, Mg, Mn, Mo, Nb, P, S, Si, Sr, Ti, V, W, Zr, and a combination thereof.

10 . A method of preparing a positive active material for a rechargeable lithium battery, comprising
mixing a precursor including a nickel-based transition metal hydroxide, a nickel-based transition metal oxide, or a combination thereof; a lithium raw material; a flux agent including an alkali metal sulfate; and silica and performing first heat treatment, and obtaining a positive active material including a single particle including a lithium nickel-based composite oxide and a coating portion disposed on the surface and containing S and Si.

11 . The method of preparing the positive active material for the rechargeable lithium battery of claim 10 , wherein
100 parts by mole to 130 parts by mole of lithium raw material, 0.1 parts by mole to 10 parts by mole of the flux agent, and 0.05 parts by mole to 5 parts by mole of the silica based on 100 moles of the transition metal including nickel of the precursor are mixed.

12 . The method of preparing the positive active material for the rechargeable lithium battery of claim 10 , wherein
the first heat treatment is performed at 750° C. to 900° C.

13 . The method of preparing the positive active material for the rechargeable lithium battery of claim 10 , wherein
the silica is hydrophobic silica.

14 . The method of preparing the positive active material for the rechargeable lithium battery of claim 10 , wherein
the first heat treatment is performed by further mixing the alkali metal phosphate

15 . The method of preparing the positive active material for the rechargeable lithium battery of claim 10 , wherein
the method of preparing the positive active material further includes washing the obtained product and performing a second heat treatment after the first heat treatment.

16 . The method of preparing the positive active material for the rechargeable lithium battery of claim 15 , wherein
the second heat treatment is performed at 600° C. to 780° C.

17 . The method of preparing the positive active material for the rechargeable lithium battery of claim 10 , wherein
the method of preparing the positive active material further includes performing cobalt coating and/or zirconium coating, and performing second heat treatment.

18 . The method of preparing the positive active material for the rechargeable lithium battery of claim 10 , wherein
in the precursor, the nickel-based transition metal oxide is represented by Chemical Formula 21 and the nickel-based transition metal hydroxide is represented by Chemical Formula 31:

wherein, in Chemical Formula 21, 0.6≤x21≤1, 0≤y21≤0.4, and M 21 and M 22 are each independently selected from Al, B, Ce, Co, Cr, F, Mg, Mn, Mo, Nb, P, S, Si, Sr, Ti, V, W, Zr, and a combination thereof, and

wherein, in Chemical Formula 31, 0.6≤x31≤1, 0≤y31≤0.4, and M 31 and M 32 are each independently selected from Al, B, Ce, Co, Cr, F, Mg, Mn, Mo, Nb, P, S, Si, Sr, Ti, V, W, Zr, and a combination thereof.

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

20 . A rechargeable lithium battery, comprising
a positive electrode including a positive active material prepared according to the method of claim 10 , a negative electrode, and an electrolyte.

Assignees

• Samsung Sdi Co Ltd

Inventors

• Kim Youngsoo
• Choi Byungjin
• Hong Suk-Gi
• Lee Changwook
• Park Jinhwan
• Yeon Dong Hee

Classifications

• H01M2004/028

  Positive electrodes · 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

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title

• C01P2006/40

  Electric properties · CPC title

• C01P2004/80

  Particles consisting of a mixture of two or more inorganic phases · CPC title