Positive electrode active material for a rechargeable lithium-ion battery

Patent metadata

Field	Value
Publication number	US-2024339605-A1
Application number	US-202218293819-A
Country	US
Kind code	A1
Filing date	Jul 30, 2022
Priority date	Aug 2, 2021
Publication date	Oct 10, 2024
Grant date	—

Abstract

The present invention relates to positive electrode active materials in rechargeable lithium-ion batteries having a difference in cobalt and nickel concentration between the center and the edge of secondary particle and having a specific range of crystallite size.

First claim

1 - 17 . (canceled)

18 . A positive electrode active material suitable for lithium-ion rechargeable batteries, said positive electrode active material comprising Li, M′, and oxygen, wherein M′ comprises:
Ni in a content x between 75.0 mol % and 95.0 mol %, relative to M′,
Co in a content y between 1.0 mol % and 25.0 mol %, relative to M′,
Mn in a content z between 0.0 mol % and 25.0 mol %, relative to M′,
Al in a content b between 0.0 mol % and 5.0 mol %, relative to M′,
Element other than Li, Ni, Mn, Co, O and Al in a content a between 0.0 mol % and 5.0 mol %, relative to M′,

wherein x, y, z, a, and b contents are measured by ICP,
wherein x+y+z+a+b is 100.0 mol %,
wherein said positive electrode active material comprises secondary particles comprising a plurality of primary particles,
wherein the positive electrode active material has a Ni content Ni edge and Co content Co edge as measured by cross-sectional EDS (CS-EDS) at the edge of the secondary particle of the positive electrode active material, wherein Ni and Co contents are expressed as mol % relative to the sum of Ni, Mn, and Co content as measured by CS-EDS at the edge of the secondary particle of the positive electrode active material,
wherein the positive electrode active material has a Ni content Ni center and Co content Co center measured by CS-EDS at the center of the secondary particle of the positive electrode active material, wherein Ni and Co contents are expressed as mol % relative to the sum of Ni, Mn, and Co content as measured by CS-EDS at the center of the secondary particle of the positive electrode active material,
wherein the ratio Ni edge /Ni center <0.98,
wherein the ratio Co edge /Co center >1.10,
wherein said secondary particles have an average crystallite size of at least 15 nm and at most 40 nm, as determined by XRD.

19 . The positive electrode active material according to claim 18 , wherein Al has a content b between 0.1 mol % and 3.0 mol %, relative to M′.

20 . The positive electrode active material according to claim 18 , wherein Ni edge /Ni center <0.97 and Co edge /Co center >1.15.

21 . The positive electrode active material according to claim 18 , wherein Ni edge /Ni center ≤0.96 and Co edge /Co center >1.30.

22 . The positive electrode active material according to claim 18 , wherein the difference between Ni edge and Ni center is at least 5 mol % and the difference between Co edge and Co center is at least 2 mol %, as determined by CS-EDS analysis.

23 . The positive electrode active material according to claim 18 , wherein a Mn content Mn edge as measured by cross-sectional EDS (CS-EDS) at the edge of the secondary particle of the positive electrode active material, wherein a Mn content is expressed as mol % relative to the sum of Ni, Mn, and Co content as measured by CS-EDS at the edge of the secondary particle of the positive electrode active material, and wherein Mn edge is higher than 0 mol %.

24 . The positive electrode active material according to claim 18 , wherein the Ni content x≥77.0 mol %, relative to M′.

25 . The positive electrode active material according to claim 18 , wherein the Ni content x≤93.0 mol %, relative to M′.

26 . The positive electrode active material according to claim 18 , wherein the Co content is 3 mol % ≤y≤20 mol %, relative to M′.

27 . The positive electrode active material according to claim 18 , wherein the element other than Li, O, Ni, Co, Mn, and Al in content a is between 0.01 mol % and 5.0 mol %, relative to M′.

28 . The positive electrode active material according to claim 18 , wherein the element other than Li, O, Ni, Co, Mn, and Al is selected from the group consisting of: B, Ba, Ca, Cr, Fe, Mg, Mo, Nb, S, Si, Sr, Ti, Y, V, W, Zn and Zr.

29 . The positive electrode active material according to claim 18 , wherein the ratio Co edge /Co 3/4 is smaller than the ratio Co edge /Co center , wherein Co 3/4 is a Co content expressed as mol % relative to the sum of Ni, Mn, and Co content as measured by CS-EDS at ¾ distance from the edge of the secondary particle to the center of the secondary particle.

30 . The positive electrode active material according to claim 18 , wherein the ratio Ni edge /Ni 3/4 is larger than the ratio Ni edge /Ni center , wherein Ni 3/4 is a Ni content expressed as mol % relative to the sum of Ni, Mn, and Co content as measured by CS-EDS at ¾ distance from the edge of the secondary particle to the center of the secondary particle.

31 . The positive electrode active material according to claim 18 , wherein 0.2≤cobalt gradient slope (mol %/μm)≤1.0 and the cobalt gradient slope is represented by the following formula:

Co
⁢

gradient
⁢

slope
⁢

(

mol
⁢

%
/
μm

)

=

Co
edge

-

Co
center

⁢

in
⁢

mol
⁢

%

distance
⁢

between
⁢

edge

-

center
⁢

in
⁢

μm

.

32 . A method for manufacturing positive the electrode active material according to claim 18 wherein the method comprises the following consecutive steps:
co-precipitating of first metal sources with a base to obtain a first M′-based intermediate precursor;
co-precipitating of first metal sources with a base and then adding said first M′-based intermediate precursor to obtain a second M′-based intermediate precursor;
precipitating second metal source with a base onto the second M′-based intermediate precursor to obtain a third M′-based precursor having a difference in cobalt and nickel concentration between their center and their edge;
mixing the obtained third M′-based precursor, having a difference in cobalt and nickel concentration between their center and their edge, with a lithium source to obtain a mixture; and
heating the mixture in an oxidizing atmosphere, at a temperature of between 650° C. and 750° C. to obtain a lithium transition metal oxide powder.

33 . A battery comprising the positive electrode active mat

Assignees

• Umicore Nv

Inventors

• Blangero Maxime
• Karakulina Olesia

Classifications

• H01M2004/028

  Positive electrodes · CPC title

• H01M10/0525

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

• C01P2006/40

  Electric properties · CPC title

• C01P2002/85

  by XPS, EDX or EDAX data · CPC title

• C01P2002/72

  by d-values or two theta-values, e.g. as X-ray diagram · CPC title