Positive Electrode Active Material for Secondary Battery and Lithium Secondary Battery Including the Same

Patent metadata

Field	Value
Publication number	US-2021305566-A1
Application number	US-202017263383-A
Country	US
Kind code	A1
Filing date	Jan 31, 2020
Priority date	Feb 1, 2019
Publication date	Sep 30, 2021
Grant date	—

Abstract

A positive electrode active material for a secondary battery which includes a nickel-based lithium composite transition metal oxide including nickel (Ni), wherein the lithium composite transition metal oxide satisfies Equation 1 and Equation 2 below80 nm≤crystallite sizeFWHM≤150 nm   [Equation 1]Δ size(|crystallite sizeIB−crystallite sizeFWHM|)≤20   [Equation 2]wherein, in Equation 1 and Equation 2, crystallite sizeFWHM is a crystallite size obtained by calculating from X-ray diffraction (XRD) data using a full width at half maximum (FWHM) method, and crystallite sizeIB is a crystallite size obtained by calculating from XRD data using an integral breadth (IB) method.

First claim

1 . A positive electrode active material for a secondary battery, comprising:
a lithium composite transition metal oxide comprising nickel (Ni), wherein the lithium composite transition metal oxide satisfies Equation 1 and Equation 2:
80 nm≤crystallite size FWHM ≤150 nm   [Equation 1]

Δ size(|crystallite size IB −crystallite size FWHM |)≤20   [Equation 2]

wherein, in Equation 1 and Equation 2, crystallite size FWHM is a crystallite size obtained by calculating from X-ray diffraction (XRD) data using a full width at half maximum (FWHM) method, and crystallite size IB is a crystallite size obtained by calculating from XRD data using an integral breadth (IB) method.

2 . The positive electrode active material for a secondary battery of claim 1 , wherein the lithium composite transition metal oxide further comprises at least one selected from the group consisting of cobalt (Co), manganese (Mn), and aluminum (Al).

3 . The positive electrode active material for a secondary battery of claim 1 , wherein an amount of the nickel (Ni) among metals excluding lithium is 60 mol % or more in the lithium composite transition metal oxide.

4 . The positive electrode active material for a secondary battery of claim 1 , wherein a particle of the lithium composite transition metal oxide is a secondary particle in which primary particles are aggregated.

5 . The positive electrode active material for a secondary battery of claim 1 , wherein the lithium composite transition metal oxide is represented by Formula 1:
Li a Ni 1−(x+y+z) Co x M′ y M″ z O 2+δ   [Formula 1]
wherein, in Formula 1, M′ is at least one selected from the group consisting of Mn and Al, M″ is at least one selected from the group consisting of barium (Ba), calcium (Ca), zirconium (Zr), titanium (Ti), magnesium (Mg), tantalum (Ta), niobium (Nb), and molybdenum (Mo), 1.0≤a≤1.5, x<y, 0≤z≤0.1, 0.1≤x+y+z≤0.4, and 0≤δ≤1.0.

6 . The positive electrode active material for a secondary battery of claim 1 , wherein the crystallite size FWHM in Equation 1 is in a range of 130 nm to 132 nm.

7 . The positive electrode active material for a secondary battery of claim 1 , wherein the Δ size(|crystallite size IB −crystallite size FWHM |) in Equation 2 is 17 or less.

8 . A method of preparing the positive electrode active material for a secondary battery of claim 1 , comprising:
mixing a lithium source and a positive electrode active material precursor including nickel (Ni), and performing primary sintering at 450° C. to 500° C.; and performing secondary sintering at 730° C. to 780° C. after the primary sintering, wherein a total sintering time of the primary sintering and the secondary sintering is 30 hours or more.

9 . The method of claim 8 , wherein the lithium source is LiOH.

10 . The method of claim 8 , wherein an amount of the nickel (Ni) among total metals is 60 mol % or more in the positive electrode active material precursor.

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

12 . A lithium secondary battery comprising the positive electrode of claim 11 .

Assignees

• Lg Chemical Ltd

Inventors

• Baek So Ra
• Lho Eun Sol
• Jung Wang Mo
• Lee Sang Wook
• Jo Eun

Classifications

• H01M10/052

  Li-accumulators · CPC title

• H01M4/131

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

• 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

• H01M4/505

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