Positive electrode active material for lithium secondary batteries, positive electrode for lithium secondary batteries, and lithium secondary battery

Patent metadata

Field	Value
Publication number	US-11024847-B2
Application number	US-201515538401-A
Country	US
Kind code	B2
Filing date	Dec 22, 2015
Priority date	Dec 25, 2014
Publication date	Jun 1, 2021
Grant date	Jun 1, 2021

Abstract

A positive electrode active material for a lithium secondary battery, including secondary particles formed by aggregation of primary particles capable of being doped and undoped with lithium ions, said positive electrode active material having: an α-NaFeO2 type crystal structure represented by formula: Li[Lix(NiaCobMncMd)1-x]O2 (I), wherein 0≤x≤0.1, 0.7<a<1, 0<b<0.2, 0≤c<0.2, 0<d<0.1, a+b+c+d=1, and M is at least one metal element selected from the group consisting of Fe, Cr, Ti, Mg, Al, Zr, Ca, Sc, V, Cr, Cu, Zn, Ga, Ge, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In and Sn; and a crystallite size α/crystallite size β ratio (α/β) of 1.60 to 2.40, wherein the crystallite size α is within a peak region of 2θ=18.7±1° and the crystallite size β is within a peak region of 2θ=44.4±1°, each determined by a powder X-ray diffraction measurement using Cu-Kα radiation.

First claim

The invention claimed is:

1. A positive electrode active material for a lithium secondary battery, comprising secondary particles that are aggregates of primary particles capable of being doped and undoped with lithium ions,
said positive electrode active material having:
an α-NaFeO 2 type crystal structure represented by formula (I) below:
Li[Li x (Ni a Co b Mn c M d ) 1-x ]O 2   (I)

wherein 0≤x≤0.1, 0.7<a<1, 0<b<0.2, 0≤c<0.2, 0<d<0.1, a+b+c+d=1, and M is at least one metal element selected from the group consisting of Fe, Cr, Ti, Mg, Al, Zr, Ca, Sc, V, Cr, Cu, Zn, Ga, Ge, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In and Sn; and
a crystallite size α/crystallite size β ratio (α/β) of 1.60 or more to 2.40 or less, wherein the crystallite size α is within a peak region of 2θ=18.7±1° and the crystallite size β is within a peak region of 2θ=44.4±1°, each determined by a powder X-ray diffraction measurement using Cu-Kα radiation, and wherein the crystallite size a is in a range of 400 Å to 900 Å.

2. The positive electrode active material according to claim 1 , wherein a product of a 10% cumulative diameter (D 10 ) and a tapped density of the positive electrode active material is 17 g·μm/mL or more to 25 g·μm/mL or less.

3. The positive electrode active material according to claim 1 , which has a BET specific surface area of 0.1 m 2 /g or more to 1.0 m 2 /g or less.

4. The positive electrode active material according to claim 1 , wherein an atomic ratio (c/b) of Mn to Co in the formula (I) is 0<c/b<1.3.

5. The positive electrode active material according to claim 1 , wherein M is Al.

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

7. A lithium secondary battery, comprising the positive electrode of claim 6 .

Assignees

• Sumitomo Chemical Co
• Tanaka Chemical Corp

Inventors

• Kageura Jun-Ichi
• Kurita Hiroyuki
• Imanari Yuichiro

Classifications

• C01G53/82

  Compounds containing nickel, with or without oxygen or hydrogen, and containing two or more other elements · 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 Primary

  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

• H01M10/0525

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