Positive active material and lithium-ion battery

Patent metadata

Field	Value
Publication number	US-2019245199-A1
Application number	US-201916249888-A
Country	US
Kind code	A1
Filing date	Jan 16, 2019
Priority date	Feb 7, 2018
Publication date	Aug 8, 2019
Grant date	—

Abstract

The present application provides a positive active material, a positive electrode and a lithium-ion battery. The positive active material comprising a first particle and a second particle, wherein the first particle has a chemical formula of Li e Co g M 1-g O 2-i , and the second particle has a chemical formula of Li f Co h N 1-h O 2-j , the element M is at least two selected from a group consisting of Ni, Mn, Al, Mg, Ti, La, Y and Zr, the element N is at least one selected from a group consisting of Ni, Mn, Al, Mg, Ti, La, Y and Zr, and 0.8≤e≤1.2, 0<g<1, −0.1≤i≤0.2, 0.8≤f≤1.2, 0<h<1, −0.1≤j≤0.2, the number of types of the element M in the first particle is greater than the number of types of the element N in the second particles. The positive active material of the present application has a good stability and can improve the capacity retention rate of the lithium-ion battery.

First claim

What is claimed is:

1 . A positive active material, comprising a first particle and a second particle, wherein the first particle has a chemical formula of Li e Co g M 1-g O 2-i , and the second particle has a chemical formula of Li f Co h N 1-h O 2-j , the element M is at least two selected from a group consisting of Ni, Mn, Al, Mg, Ti, La, Y and Zr, the element N is at least one selected from a group consisting of Ni, Mn, Al, Mg, Ti, La, Y and Zr, and 0.8≤e≤1.2, 0<g<1, −0.1≤i≤0.2, 0.8≤f≤1.2, 0<h<1, −0.1≤j≤0.2, the number of types of the element M in the first particle is greater than the number of types of the element N in the second particles.

2 . The positive active material according to claim 1 , wherein the first particle has a chemical formula of Li n Co x M 1-x O 2-y , and the second particle has a chemical formula of Li n Co x N 1-x O 2-y , and 0.8≤n≤1.2, 0<x<1, −0.1≤y≤0.2.

3 . The positive active material according to claim 1 , wherein the particle diameter of the first particle is smaller than the particle diameter of the second particle.

4 . The positive active material according to claim 3 , wherein the particle diameter of the first particle is smaller than Dv50 of the positive active material, and the particle diameter of the second particle is larger than Dv50 of the positive active material.

5 . The positive active material according to claim 1 , wherein each of the elements M is contained in the first particle in an amount of more than 200 ppm, and each of the elements N is contained in the second particle in an amount of more than 200 ppm.

6 . The positive active material according to claim 1 , wherein the positive active material meets the following formula (1):
( a/b )/( c/d )>1   formula (1)
a represents the total mass of the element M in the first particle; b represents the mass of the element Co in the first particle; c represents the total mass of the element N in the second particle; d represents the mass of the element Co in the second particle.

7 . The positive active material according to claim 1 , wherein the positive active material meets the following formula (2):
( A/B )/( C/D )>1   formula (2)
A represents the total molar amount of the element M in the first particle; B represents the molar amount of the element Co in the first particle; C represents the total molar amount of the element N in the second particle; D represents the molar amount of the element Co in the second particle.

8 . The positive active material according to claim 6 , wherein the positive active material has a value of (a/b)/(c/d) of 1.3 to 10.

9 . The positive active material according to claim 1 , wherein the volume-based particle size distribution curve of the positive active material comprises a first peak and a second peak.

10 . The positive active material according to claim 9 , wherein the peak height of the second peak is greater than the peak height of the first peak.

11 . The positive active material according to claim 1 , wherein the particle diameter of the positive active material meets the following formula (3):
( Dv 90− Dv 50)−( Dv 50− Dv 10)≤2.5   formula (3).

12 . A positive electrode, wherein comprising a positive active material, wherein the positive active material comprising a first particle and a second particle, wherein the first particle has a chemical formula of Li e Co g M 1-g O 2-i , and the second particle has a chemical formula of Li f Co h N 1-h O 2-j , the element M is at least two selected from a group consisting of Ni, Mn, Al, Mg, Ti, La, Y and Zr, the element N is at least one selected from a group consisting of Ni, Mn, Al, Mg, Ti, La, Y and Zr, and 0.8≤e≤1.2, 0<g<1, −0.1≤i≤0.2, 0.8≤f≤1.2, 0<h<1, −0.1≤j≤0.2, the number of types of the element M in the first particle is greater than the number of types of the element N in the second particles.

13 . The positive electrode according to claim 12 , wherein the particle diameter of the first particle is smaller than the particle diameter of the second particle.

14 . The positive electrode according to claim 13 , wherein the particle diameter of the first particle is smaller than Dv50 of the positive active material, and the particle diameter of the second particle is larger than Dv50 of the positive active material.

15 . The positive electrode according to claim 12 , wherein each of the elements M is contained in the first particle in an amount of more than 200 ppm, and each of the elements N is contained in the second particle in an amount of more than 200 ppm.

16 . The positive electrode according to claim 12 , wherein the positive active material meets the following formula (1):
( a/b )/( c/d )>1   formula (1)
a represents the total mass of the element M in the first particle; b represents the mass of the element Co in the first particle; c represents the total mass of the element N in the second particle; d represents the mass of the element Co in the second particle.

17 . The positive electrode according to claim 12 , wherein the positive active material meets the following formula (2):
( A/B )/( C/D )>1   formula (2)
A represents the total molar amount of the element M in the first particle; B represents the molar amount of the element Co in the first particle; C represents the total molar amount of the element N in the second particle; D represents the molar amount of the element Co in the second particle.

18 . A lithium-ion battery, wherein comprising a positive electrode with a positive active material, wherein the positive active material comprising a first particle and a second particle, wherein the first particle has a chemical formula of Li e Co g M 1-g O 2-i , and the second particle has a chemical formula of Li f Co h N 1-h O 2-j , the element M is at least two selected from a group consisting of Ni, Mn, Al, Mg, Ti, La, Y and Zr, the element N is at least one selected from a group consisting of Ni, Mn, Al, Mg, Ti, La, Y and Zr, and 0.8≤e≤1.2, 0<g<1, −0.1≤i≤0.2, 0.8≤f≤1.2, 0<h<1, −0.1≤j≤0.2, the number of types of the element M in the first particle is greater than the number of types of the element N in the second particles.

19 . The lithium-ion battery according to claim 18 , wherein the compact density of the positive electrode is g/cm 3 .

20 . The lithium-ion battery according to claim 18 , wherein the particle diameter of the first particle is smaller than the particle diameter of the second particle.

Assignees

• Ningde Amperex Technology Ltd

Inventors

• Zeng Qiao
• Wang Kefei

Classifications

• C01P2004/51

  Particles with a specific particle size distribution · CPC title

• C01G51/50

  of the type (MnO2)n-, e.g. Li(CoxMn1-x)O2 or Li(MyCoxMn1-x-y)O2 · CPC title

• C01G51/42

  containing alkali metals, e.g. LiCoO2 · CPC title

• C01P2006/40

  Electric properties · CPC title

• C01P2004/61

  Micrometer sized, i.e. from 1-100 micrometer · CPC title