Positive electrode active material for secondary battery, method of preparing the same, and lithium secondary battery including the positive electrode active material

Patent metadata

Field	Value
Publication number	US-11424436-B2
Application number	US-201816617273-A
Country	US
Kind code	B2
Filing date	Oct 17, 2018
Priority date	Oct 26, 2017
Publication date	Aug 23, 2022
Grant date	Aug 23, 2022

Abstract

A method of preparing a positive electrode active material for a secondary battery includes preparing a precursor of a composite transition metal oxide compound represented by Formula 1, and mixing the precursor, a lithium source, and a doping element source and sintering the mixture to form a doped lithium composite transition metal oxide, wherein the doping element source is a hydroxide-based compound.Ni1−(x1+y1)Cox1May1(OH)2  [Formula 1]wherein, Ma is at least one element selected from the group consisting of manganese (Mn) and aluminum (Al), and 0<x1≤0.4, 0<y1≤0.4, and 0<x1+y1≤0.4. The positive electrode active material satisfies a weight loss ratio at 600° C. of 1.0% or less and a weight loss ratio at 900° C. of 2.0% or less during thermogravimetric analysis (TGA).

First claim

The invention claimed is:

1. A positive electrode active material for a secondary battery, comprising a lithium composite transition metal oxide which includes nickel (Ni), cobalt (Co), at least one doping element, and at least one selected from the group consisting of manganese (Mn) and aluminum (Al),
wherein an amount of nickel (Ni) among total transition metals in the lithium composite transition metal oxide is 60 mol % or more,
wherein the at least one doping element comprises zirconium (Zr), magnesium (Mg), titanium (Ti), or barium (Ba), tantalum (Ta), niobium (Nb), molybdenum (Mo), tungsten (W), and chromium (Cr),
wherein 30 mol % or more of a total amount of the at least one doping element is contained in a core region corresponding to 50% of a radius from a center of a particle of the lithium composite transition metal oxide to a surface thereof which is located near the center, and
wherein the positive active material has a weight loss ratio at 600° C. and a weight loss ratio at 900° C. of 1.0% or less and 2.0% or less, respectively, when measured by thermogravimetric analysis (TGA) at a heating rate of 20° C. per minute under ambient air flow of 50 milliliters per minute.

2. The positive electrode active material for a secondary battery of claim 1 , wherein the at least one doping element is included in an amount of 1,000 ppm to 10,000 ppm.

3. The positive electrode active material for a secondary battery of claim 1 , wherein the lithium composite transition metal oxide is represented by Formula 2:
Li p Ni 1−(x2+y2+z2) Co x2 M a y2 M b z2 M c q2 O 2   [Formula 2]

wherein, M a is at least one element selected from the group consisting of Mn and Al, M b is at least one element selected from the group consisting of Zr, Mg, Ti, and Ba, M c is at least one element selected from the group consisting of, Zr, Ti, Mg, Ta, Nb, Mo, W, and Cr, and 0.9≤p≤1.5, 0<x2≤0.4, 0<y2≤0.4, 0≤z2≤0.1, 0≤q2≤0.1, and 0<x2+y2+z2≤0.4.

4. The positive electrode active material for a secondary battery of claim 1 , wherein an amount of residual lithium by-products present in the lithium composite transition metal oxide is 0.6 wt % or less.

5. The positive electrode active material for a secondary battery of claim 1 , wherein cation disorder of Ni cations of a lithium layer in a lithium composite transition metal oxide structure is 0.5% or less.

6. The positive electrode material for a secondary battery of claim 1 , wherein 40 mol % to 60 mol % of a total amount of the at least one doping element is contained in a core region corresponding to 50% of a radius from a center of a particle of the lithium composite transition metal oxide to a surface thereof which is located near the center.

7. A positive electrode for a secondary battery comprising the positive electrode active material of claim 1 .

8. A lithium secondary battery comprising the positive electrode of claim 7 .

Assignees

• Lg Chern Ltd
• Lg Chemical Ltd

Inventors

• Park Na Ri
• Park Sung Soon

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

• H01M10/0525

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

• H01M4/505

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

• C01G53/44 Primary

  containing manganese · CPC title

• H01M2004/028

  Positive electrodes · CPC title