Positive electrode active material for nonaqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-2020203728-A1
Application number	US-202016808525-A
Country	US
Kind code	A1
Filing date	Mar 4, 2020
Priority date	Mar 31, 2016
Publication date	Jun 25, 2020
Grant date	—

Abstract

A positive electrode active material for a nonaqueous electrolyte secondary battery includes particles of a lithium-transition metal composite oxide that contains nickel in the composition thereof and has a layered structure. The particles have an average particle size D SEM based on electron microscopic observation in a range of 1 μm to 7 μm in which a ratio D 50 /D SEM of a 50% particle size D 50 in volume-based cumulative particle size distribution to the average particle size based on electron microscopic observation is in a range of 1 to 4, and a ratio D 90 /D 10 of a 90% particle size D 90 to a 10% particle size D 10 in volume-based cumulative particle size distribution is 4 or less.

First claim

What is claimed is:

1 . A positive electrode active material for a nonaqueous electrolyte secondary battery, comprising particles of a lithium-transition metal composite oxide that contains nickel in the composition thereof and has a layered structure, the particles having an average particle size D SEM based on electron microscopic observation in a range of 1 μm to 7 μm, wherein
a ratio D 50 /D SEM of a 50% particle size D 50 in volume-based cumulative particle size distribution to the average particle size based on electron microscopic observation is in a range of 1 to 4, and
a ratio D 90 /D 10 of a 90% particle size D 90 to a 10% particle size D 10 in volume-based cumulative particle size distribution is 4 or less; and wherein the D SEM is to be determined as follows: observing an image at a magnification of 1,000 to 10,000 using a scanning electron microscope (SEM), selecting 100 particles having recognizable outlines, calculating the equivalent spherical diameters of the selected particles using an image processing software, and determining the arithmetic average of the obtained equivalent spherical diameters as D SEM .

2 . The positive electrode active material according to claim 1 , wherein the ratio D 50 /D SEM of the D 50 to the D SEM is 1 to 3.

3 . The positive electrode active material according to claim 1 , wherein the lithium-transition metal composite oxide has a composition represented by the following formula (1):
Li p Ni x Co y M 1 Z O 2+α   (1),
wherein p, x, y, z, and a satisfy 1.0≤p≤1.3, 0.3≤x≤0.95, 0≤y≤0.4, 0≤z≤0.5, x+y+z=1, and −0.1≤α≤0.1, and M 1 represents at least one of Mn and Al.

4 . The positive electrode active material according to claim 3 , wherein 0.3≤x<0.8, and the ratio D 50 /D SEM of the D 50 to the D SEM is in a range of 1 to 2.

5 . The positive electrode active material according to claim 3 , wherein 0.3≤x<0.6, and a disorder of nickel element in the lithium-transition metal composite oxide particles determined by X-ray diffractometry is 1.5% or less.

6 . The positive electrode active material according to claim 3 , wherein 0.3≤x<0.6, and the ratio D 90 /D 10 of the D 90 to the D 10 is 3 or less.

7 . The positive electrode active material according to claim 3 , wherein 0.3≤x<0.6, and the ratio D 90 /D 10 of the D 90 to the D 10 is 2.5 or less.

8 . The positive electrode active material according to claim 3 , wherein 0.3≤x<0.6, and the D 50 is in a range of 1 μm to 5.5 μm.

9 . The positive electrode active material according to claim 3 , wherein 0.3≤x<0.6, and the D 50 is in a range of 1 μm to 3 μm.

10 . The positive electrode active material according to claim 3 , wherein, when 0.3≤x<0.6, 1.1<p<1.2.

11 . The positive electrode active material according to claim 3 , wherein 0.6≤x<0.8, and the disorder of elemental nickel in the lithium-transition metal composite oxide particles determined by X-ray diffractometry is 2.0% or less.

12 . The positive electrode active material according to claim 3 , wherein 0.6≤x<0.8, and the ratio D 90 /D 10 of the D 90 to the D 10 is 2.3 or less.

13 . The positive electrode active material according to claim 3 , wherein 0.6≤x<0.8, and the D 50 is in a range of 1 μm to 5.5 μm.

14 . The positive electrode active material according to claim 3 , wherein 0.8≤x≤0.95, and the disorder of elemental nickel determined by X-ray diffractometry is 4.0% or less.

15 . The positive electrode active material according to claim 3 , wherein 0.8≤x≤0.95, and the ratio D 90 /D 10 of the D 90 to the D 10 is 3 or less.

16 . The positive electrode active material according to claim 3 , wherein 0.8≤x≤0.95, and the D 50 is in a range of 1 μm to 5.5 μm.

17 . An electrode for a nonaqueous electrolyte secondary battery, comprising:
a current collector; and a positive electrode active material layer that is disposed on the current collector and contains the positive electrode active material according to claim 1 .

18 . A nonaqueous electrolyte secondary battery comprising the electrode according to claim 17 .

Assignees

• Honda Motor Co Ltd
• Nichia Corp

Inventors

• Ogawa Atsushi
• Kawamura Soshi
• Sukigara Toru
• Maeyama Hiroto
• Kobayashi Kenichi

Classifications

• Y02E60/10

  Energy storage using batteries · CPC title

• C01P2006/40

  Electric properties · CPC title

• C01P2002/50

  Solid solutions · CPC title

• H01M2220/20

  Batteries in motive systems, e.g. vehicle, ship, plane · CPC title

• C01P2002/20

  Two-dimensional structures · CPC title