High-compacted-density positive electrode material and electrochemical energy storage apparatus

Patent metadata

Field	Value
Publication number	US-2021126242-A1
Application number	US-202017135552-A
Country	US
Kind code	A1
Filing date	Dec 28, 2020
Priority date	Dec 29, 2018
Publication date	Apr 29, 2021
Grant date	—

Abstract

This application relates to the field of battery technologies, and in particular, to a high-compacted-density positive electrode material and an electrochemical energy storage apparatus. The positive electrode material includes a lithium-nickel transition metal oxide A and a lithium-nickel transition metal oxide B. The lithium-nickel transition metal oxide A is secondary particles, whose chemical formula is shown in formula I: Lia1(Nib1Coc1Mnd1)x1M1-x1O2-e1Xe1. The lithium-nickel transition metal oxide B is a monocrystalline structure or a monocrystalline-like structure, whose chemical formula is shown in formula II: Lia2(Nib2Coc2Mnd2)x2M′1-x2O2-e2X′e2 (II). The positive electrode material of this application includes the large-particle lithium-nickel transition metal oxide A and the small-particle lithium-nickel transition metal oxide B to improve an energy density of the battery. A degree of crystallinity and particle size distribution of the mixed positive electrode material can improve a compacted density of the high-nickel active material, and ensure lower gassing and good cycle performance.

First claim

What is claimed is:

1 . A positive electrode material, wherein the positive electrode material includes a lithium-nickel transition metal oxide A and a lithium-nickel transition metal oxide B, the lithium-nickel transition metal oxide A is secondary particles, and a chemical formula of the lithium-nickel transition metal oxide A is shown in Formula I:
Li a1 (Ni b1 Co c1 Mn d1 ) x1 M 1-x1 O 2-e1 X e1   (I)
in Formula I, 0.9≤a1≤1.05, 0.7≤b1≤0.98, 0.01≤c1≤0.15, 0.01≤d1≤0.3, 0.95≤x1≤1, and 0≤e1≤0.1, wherein M is selected from any one or a combination of Al, Ti, Zr, Nb, Sr, Sc, Sb, Y, Ba, B, C, Co, and Mn, and X is selected from F and/or Cl; the lithium-nickel transition metal oxide B is monocrystalline or monocrystalline-like particles, and a chemical formula of the lithium-nickel transition metal oxide B is shown in Formula II:
Li a2 (Ni b2 Co c2 Mn d2 ) x2 M′ 1-x2 O 2-e2 X′ e2   (II)

in Formula II, 0.95≤a2≤1.05, 0.7≤b2≤0.98, 0.01≤c2≤0.15, 0.01≤d2≤0.3, 0.95≤x2≤1, and 0≤e2≤0.1, wherein M′ is selected from any one or a combination of Al, Ti, Zr, Nb, Sr, Sc, Sb, Y, Ba, B, C, Co, and Mn, and X is selected from F and/or Cl; and a crystal size D 104 of the positive electrode material and a particle size distribution change rate ΔPSD of the positive electrode material satisfy:
50 nm≤ D 104 ×ΔPSD≤450 nm, wherein

ΔPSD is a particle size distribution change rate calculated according to the formula ΔPSD=(D v 90−D v 10)/D v 50 based on a measured particle size of volume particle distribution of the positive electrode material, and D 104 is a crystal size obtained by fitting a peak value of a 104 crystal plane through XRD ray diffraction testing on the positive electrode material.

2 . The positive electrode material according to claim 1 , wherein the positive electrode material satisfies: 80 nm≤D 104 ×ΔPSD≤250 nm.

3 . The positive electrode material according to claim 1 , wherein ΔPSD is within a range of 1.2 to 3.1.

4 . The positive electrode material according to claim 1 , wherein ΔPSD is within a range of 1.5 to 2.2.

5 . The positive electrode material according to claim 1 , wherein the lithium-nickel transition metal oxide A has a single-particle pressure-resistant strength of ≥100 MPa, and the lithium-nickel transition metal oxide B has a single-particle pressure-resistant strength of ≥50 MPa.

6 . The positive electrode material according to claim 1 , wherein the lithium-nickel transition metal oxide A has D v 50 of 8 μm to 15 μm, D v 10 of 3 μm to 8 μm, and D v 90 of 15 μm to 25 μm.

7 . The positive electrode material according to claim 1 , wherein the lithium-nickel transition metal oxide A comprises secondary particles composed of primary particles, and the primary particles have a particle size of 30 nm to 800 nm.

8 . The positive electrode material according to claim 1 , wherein the lithium-nickel transition metal oxide A comprises secondary particles composed of primary particles, and the primary particles have a particle size of 200 nm to 500 nm.

9 . The positive electrode material according to claim 1 , wherein the lithium-nickel transition metal oxide B has D v 50 of 1 μm to 7 μm, D v 10 of 1 μm to 3 μm, and D v 90 of 5 μm to 10 μm.

10 . The positive electrode material according to claim 1 , wherein the lithium-nickel transition metal oxide B has D v 50 of 3 μm to 5 μm, D v 10 of 1 μm to 3 μm, and D v 90 of 5 μm to 10 μm.

11 . The positive electrode material according to claim 1 , wherein a mass ratio of the lithium-nickel transition metal oxide A to the lithium-nickel transition metal oxide B is 10:1 to 1:1.

12 . The positive electrode material according to claim 1 , wherein a mass ratio of the lithium-nickel transition metal oxide A to the lithium-nickel transition metal oxide B is 4:1 to 2:1.

13 . The positive electrode material according to claim 1 , wherein a specific surface area of the positive electrode material is 0.5 m 2 /g to 1.5 m 2 /g.

14 . The positive electrode material according to claim 1 , wherein a specific surface area of the positive electrode material is 0.6 m 2 /g to 1.0 m 2 /g.

15 . The positive electrode material according to claim 1 , wherein the positive electrode material has a compacted density of 3.3 g/cm 3 to 3.7 g/cm 3 .

16 . The positive electrode material according to claim 1 , wherein the lithium-nickel transition metal oxide A and/or the lithium-nickel transition metal oxide B are surface-modified, the surface modification method comprising one or a combination of doping the particle surface, oxide coating the particle surface, and carbon coating the particle surface, wherein doping and coating elements are selected from one or a combination of Mg, Al, Ti, Co, Fe, Cd, Zr, Mo, Zn, B, P, Cu, V, and Ag.

17 . An electrochemical energy storage apparatus, comprising the positive electrode material according to claim 1 .

Assignees

• Contemporary Amperex Technology Co Ltd

Inventors

• Du Rui
• Liu Yongchao
• Zhao Deyu
• Liu Na

Classifications

• C01G53/82

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

• C01P2004/61

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

• C01G53/42

  containing alkali metals, e.g. LiNiO2 · CPC title

• C01P2002/60

  Compounds characterised by their crystallite size · CPC title

• C01P2004/51

  Particles with a specific particle size distribution · CPC title