Positive electrode material for rechargeable lithium ion batteries

Patent metadata

Field	Value
Publication number	US-11522186-B2
Application number	US-202016909179-A
Country	US
Kind code	B2
Filing date	Jun 23, 2020
Priority date	Dec 22, 2017
Publication date	Dec 6, 2022
Grant date	Dec 6, 2022

Abstract

A positive electrode active material for a lithium ion battery comprises a lithium transition metal-based oxide powder, the powder comprising single crystal monolithic particles comprising Ni and Co and having a general formula Li 1+a (Ni z Mn y Co x Zr q A k ) 1−a O 2 , wherein A is a dopant, −0.025≤a<0.005, 0.60≤z≤0.95, y≤0.20, 0.05≤x≤0.20, k≤0.20, 0≤q≤0.10, and x+y+z+k+q=1. The particles have a cobalt concentration gradient wherein the particle surface has a higher Co content than the particle center.

First claim

The invention claimed is:

1. A positive electrode active material for a lithium ion battery, comprising a lithium transition metal-based oxide powder, the powder comprising single crystal monolithic particles, said particles having a particle center and a particle surface and comprising Ni and Co and having a general formula Li 1+a (Ni z Mn y Co x Zr q A k ) 1−a O 2 , wherein A is a dopant, −0.025≤a<0.005, 0.60≤z≤0.95, y≤0.20, 0.05≤x≤0.20, k≤0.20, 0<q≤0.10, and x+y+z+k+q=1, the particles having a cobalt concentration gradient wherein the particle surface has a higher Co content than the particle center and wherein the particles have a Zr concentration gradient wherein the particle surface has a higher Zr content than the particle center and wherein either
when Mn is present, a ratio between a Co/Mn molar ratio at the particle surface and a Co/Mn molar ratio at a distance d from the surface is between 1.1 and 1.4, whereby d=¼ of the distance from the particle surface to the particle center, or
when Mn is absent, a ratio between C(4)/C(3) is between 1.1 and 1.4, wherein C(4) is the Co/(Ni+Co) molar ratio at the particle surface and C(3) is the Co/(Ni+Co) molar ratio at a distance d from the surface, whereby either d=¼ or d=¾ of the distance from the particle surface to the particle center.

2. The positive electrode active material of claim 1 , wherein the powder has a particle size distribution with D50<10 μm.

3. The positive electrode active material of claim 1 , when Mn is present, wherein the ratio between the Co/Mn molar ratio at the particle surface and the Co/Mn molar ratio at the particle center is between 1.4 and 1.5.

4. The positive electrode active material of claim 1 , wherein the cobalt concentration gradient varies continuously from the surface to the center of the particles.

5. The positive electrode active material of claim 1 , wherein the particles have a morphology with multiple flat surfaces and an aspect ratio of at least 0.8.

6. The positive electrode active material of claim 1 , wherein the particles have a surface layer comprising LiCoO 2 .

7. A solid state lithium ion battery or a lithium ion battery provided with a liquid electrolyte, comprising the powderous positive electrode material of claim 1 being cycled up to a voltage of at least 4.35V.

Assignees

• Umicore Nv
• Umicore Korea Ltd

Inventors

• Paulsen Jens
• Yang Hyejeong
• Kim Jihye

Classifications

• C01P2004/84

  one phase coated with the other · CPC title

• H01M4/131

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

• C01P2004/54

  Particles characterised by their aspect ratio, i.e. the ratio of sizes in the longest to the shortest dimension · CPC title

• H01M4/505

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

• C01P2002/54

  one element only · CPC title