Cathode active material for li-ion secondary batteries and preparation method therefor

Abstract

The present disclosure provides a cathode active material, comprising Li, M' and oxygen, wherein M' has a formula: NixMnyCozQa, Q being another element than Ni, Mn, and Co, wherein : - 85.0 at% ≤ x ≤ 95.0 at%, - 0.0 at% ≤ y ≤ 5.0 at%, - 0.0 at% ≤ z ≤ 5.0 at%, and - 0.0 at% ≤ a ≤ 5.0 at%, with x+y+z+a = 100.0 at% as determined by ICP-OES, the cathode active material powder comprising secondary particles including a plurality of primary particles, wherein the primary particles have an aspect ratio of at least 4.0 and of at most 5.0, wherein the primary particle have a (110) / (108) ratio of at least 0.90 and of at most 0.95, or of at least 0.92 and of at most 0.93..

Description

CATHODE ACTIVE MATERIAL FOR LI-ION SECONDARY BATTERIES AND PREPARATION METHOD THEREFORTECHNICAL FIELD

[0001] The present disclosure relates to a cathode active material (hereafter referred to as CAM) powder comprising lithium (Li), nickel (Ni), manganese (Mn) and cobalt (Co). Such a CAM powder is also referred hereunder as NMC (NiMnCo) CAM powder. The terms 'CAM' and 'CAM powder' can be used interchangeably.

[0002] The term "comprising", as used herein and in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It needs to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression "a composition comprising components A and B" should not be limited to compositions consisting only of components A and B. It means that with respect to the present disclosure, the only relevant components of the composition are A and B. Accordingly, the terms "comprising" and "including" encompass the more restrictive terms "consisting essentially of" and "consisting of".

[0003] The term "a cathode active material" as used herein and claimed is defined as a material which is electrochemically active in a positive electrode or cathode. By active material, it must be understood to be a material capable of capturing and releasing Li ions when subjected to a predetermined voltage change over a predetermined period of time. The NMC CAM according to the present disclosure is suitable to be used in Li-ions secondary batteries (hereafter referred to as LIBs).

[0004] In particular, the present disclosure relates to a NMC CAM containing a high content of Ni, hereafter referred to as hNMC. For instance, an hNMC CAM comprises a Ni / (Ni + Mn+Co) ratio of at least 60.0 at% (e.g., NMC622) or even of at least 80.0 at% (e.g., NMC811). In the present disclosure, "at%" signifies atomic percentage. The at% or "atomic percent" of a given element means a percentage of atoms of said element among all atoms in a claimed composition. at% can be measured by inductively coupled plasma - optical emission spectrometry (hereafter referred to as ICP-OES).

[0005] The present disclosure also relates to a process for manufacturing the CAM from a precursor of the CAM (hereafter referred to as pCAM); to a battery comprising the CAM; and to an (hybrid) electric vehicle (hereafter referred to as (H)EV) including the battery as well as the use of the battery in the (hybrid) electric vehicle. The term "precursor (of a CAM) or (CAM) precursor" as used herein and claimed is defined as a material suitable for manufacturing of a cathode material. By precursor, it must be understood a material that requires to be reacted with a Li ions source to make the cathode active material.BACKGROUND

[0006] Along with the developments of EVs and HEVs, it comes a demand for LIBs eligible for such applications and hNMC CAMs are expected to be widely used materials therein, because of their high mass or volumetric energy density, and their higher (discharge) capacities at higher operating voltages.

[0007] In particular, hNMC CAM powders having a polycrystalline morphology, i.e. hNMC CAMs comprising secondary particles including a plurality of primary particles, have been extensively investigated. For instance, US11,837,722B2 (hereafter referred to as US'722) discloses a hNMC CAM powder wherein secondary particles have primary particles with an optimized radial distribution. US2020 / 0403240A1 (hereafter referred to as US'240) also contemplates a hNMC CAM powder which secondary particles include primary particles with an optimal orientation. According to US'722 and US'240, optimal orientation of primary particles is necessary to achieve high capacity hNMC CAM with increased lifespan. Nonetheless, battery cycling performances of the CAM according to prior art remain limited.

[0008] WO2021 / 047324 (or US20220185699) contemplates an hNMC CAM secondary particle including primary particles having an optimized aspect ratio of for instance 4.5. EP4149890A1 (or WO2021228662A1) also discloses an hNMC CAM secondary particles having an aspect ratio of at least 4.0.

[0009] Still, there is a need to further optimize electrochemical (hereafter referred to as EC) performances of hNMC CAMs.SUMMARY OF THE DISCLOSURE

[0010] Therefore, it is a first object of the present disclosure to provide a hNMC CAM having a lowered capacity fading rate, i.e., QF01C, while retaining high capacity, e.g. a high first cycle discharge capacity (DQ1).

[0011] A second object of the disclosures includes a process for manufacturing the hNMC CAM with improved EC performances.

[0012] A third object of the disclosure relates to a battery including the CAM according to the disclosure.

[0013] A fourth object of the disclosure covers an EV or a HEV including the battery according to the disclosure.

[0014] The first object of the disclosure is achieved by providing a cathode active material powder according to claim 1, comprising Li, M' and oxygen, wherein M' has a formula : NixMnyCozQa, Q being another element than Ni, Mn, and Co, wherein :- 80.0 at% < x < 100.0 at%,- 0.0 at% < y < 9.0 at%,- 0.0 at% < z < 9.0 at%, and- 0.0 at% < a < 1.0 at%, or:- 80.0 at% < x < 95.0 at%,- 0.0 at% < y < 9.0 at%,- 0.0 at% < z < 9.0 at%, and- 0.0 at% < a < 1.0 at%,, or:- 85.0 at% < x < 95.0 at%,- 0.0 at% < y < 5.0 at%,- 0.0 at% < z < 5.0 at%, and- 0.0 at% < a < 5.0 at%, with x+y+z+a = 100.0 at% as determined by ICP-OES, the cathode active material powder comprising secondary particles including a plurality of primary particles, wherein the primary particles have an aspect ratio of at least 4.0 and of at most 4.8, wherein the primary particle have a crystal size (110) / (108) ratio of at least 0.90 and of at most 0.95, or of at least 0.90 and of at most 0.93, or of at least 0.90 and of at most 0.92, or of at least 0.92 and of at most 0.93.

[0015] It is indeed observed that the CAM according to claim 1 allows a decrease of QF01C and an improved DQ1, as illustrated by examples of the present disclosure.

[0016] In the framework of the present disclosure, the terms "aspect ratio" refer to a L / D ratio, wherein :- L is a longest length (or length) of a primary particle and- D is a longest width (or width) of the primary particle.The aspect ratio is an averaged L / D of at least 20 primary particles and L and D are expressed in pm and measured based a on cross-section (hereafter referred to as CS) scanning electron microscopy (hereafter referred to as SEM) image of primary particles, according to the analysis method provided in Section G below. The aspect ratio can be of at least 4.0 and of at most 5.0, or of at least 4.0 and of at most 4.8, or even of at least 4.0 and at most 4.2.

[0017] The terms "crystal size (110) / (108) ratio" refer to a (110) to (108) crystallites sizes ratio. This crystal size (110) / (108) ratio is measured by XR.D. Crystallite size of (110) and (108) peaks are calculated by Scherrer equation and measured, as well as their ratio, according to the analysis method provided in Section E below. (110) and (108) crystallite sizes are also referred to as (110) and (108) crystal plane sizes since they each refer to the sizes of the planes (110) and (108) of a crystal, respectively.

[0018] The present disclosure includes the following aspects:CAM powder

[0019] In one aspect of the CAM, the secondary particles comprise Li, M' and oxygen, wherein M' has a formula NixMnyCozQa, wherein :- 80.0 at% < x < 100.0 at%,- 0.0 at% < y < 9.0 at%,- 0.0 at% < z < 9.0 at%, and- 0.0 at% < a < 1.0 at%, with x+y+z+a = 100.0 at% as determined by ICP- OES, or:- 80.0 at% < x < 95.0 at%,- 0.0 at% < y < 9.0 at%,- 0.0 at% < z < 9.0 at%, and- 0.0 at% < a < 1.0 at%, with x+y+z+a = 100.0 at% as determined by ICP- OES, or:85.0 at% < x < 95.0 at%,0.0 at% < y < 5.0 at%,0.0 at% < z < 5.0 at%, and0.0 at% < a < 5.0 at%, with x+y+z+a = 100.0 at% as determined by ICP- OES.

[0020] The secondary particles of the CAM powder according to the present disclosure may include Ni, Mn, Co and Q in respective contents as follows:- 90.0 at% < x < 95.0 at%,- 0.0 at% < y < 3.0 at%,- 0.0 at% < z < 3.0 at%, and- 0.0 at% < a < 4.0 at%, with x+y+z+a = 100.0 at% as determined by ICP- OES, or as follows:93.0 at% < x < 94.0 at%,- 0.0 at% < y < 3.0 at%,- 0.0 at% < z < 3.0 at%, and- 0.0 at% < a < 1.0 at%, with x+y+z+a = 100.0 at% as determined by ICP- OES.

[0021] Optionally Q in the secondary particles of the CAM powder according to the disclosure is at least one element of: Al, Mg, Zr, Nb, W, B, Si, Ba, Sr, Ca, Zn, Cr, V, Y, Sb, Ta, Mo, and Ti.

[0022] The secondary particles of the CAM powder according to the disclosure may have a Li / M' (at% / at%) ratio of at least 0.95 and at most 1.06, or of at least 0.99 and at most 1.05, or of 1.015. Optionally, the Li / M' (at% / at%) ratio is of at least 1.005 and at most 1.015, or of at least 1.00 or 1.009 and at most 1.014, or of 1.012. The Li / M' (at% / at%) is determined by ICP-OES.

[0023] Optionally, the secondary particles of the cathode active material of the disclosure may consist of Li, O and M, wherein M consists of Ni, Mn, Co, and Q, wherein each of the elements included in M is present in the CAM in any of abovedescribed contents.

[0024] The cathode active material powder according to the disclosure may have primary particles with an aspect ratio of at least 4.0 and of at most 4.5, or of at least 4.0 and of at most 4.2. The aspect ratio of CAM primary particles can be of at least 4.1 and of at most 4.5, or of at least 4.1 and of at most 4.2.

[0025] The cathode active material powder according to the disclosure may have a (110) crystallite size of at least 35 nm and at most 40 nm as measured by XR.D calculated by the Scherrer equation.

[0026] The cathode active material powder according to the disclosure may have a (108) crystallite size of at least 40 nm and at most 45 nm as measured by XR.D calculated by the Scherrer equation.

[0027] The cathode active material powder according to the disclosure may have a (110) crystallite size of at least 35 nm and at most 40 nm and a (108) crystallite size of at least 40 nm and at most 45 nm as measured by XR.D calculated by the Scherrer equation.

[0028] Optionally, the primary particles of the CAM powder according to the disclosure have an averaged degree of radial orientation of at least 15.0° and of at most 25.0°. The terms "averaged degree of radial orientation" refers to an average angle between: a) a reference line that is a first line connecting a first center portion of a secondary particle and a second center portion of a primary particle having an edge, the primary particle being provided at an outermost portion of the secondary particle, and b) a primary particle orientation line that is a second line passing through the second center portion of the primary particle located at the outermost portion of the secondary particle, and extending in parallel to an orientation direction of the primary particle, the orientation direction being a vector parallel to an orientation line connecting a first and a second points location on the edge of the primary particle that are most distant from one another. The averaged degree of orientation is measured according to the method described in Section F below.

[0029] The average radial angle can be of at least 20.0° and of at most 25.0°.

[0030] The cathode active material powder according to the present disclosure may include Ni, Mn, Co and Q in respective contents as follows:- 90.0 at% < x < 95.0 at%,- 2.0 at% < y < 3.0 at%,- 2.0 at% < z < 3.0 at%, and- 1.0 at% < a < 4.0 at%, or as follows:- 90.0 at% < x < 95.0 at%,- 2.5 at% < y < 3.0 at%,- 2.5 at% < z < 3.0 at%, and- 0.0 at% < a < 4.0 at%,or as follows:93.0 at% < x < 94.0 at%,- 3.0 at% < y < 3.0 at%,- 3.0 at% < z < 3.0 at%, and- 0.0 at% < a < 1.0 at%, or:- 80.0 at% < x < 100.0 at%,- 0.0 at% < y < 9.0 at%,- 0.0 at% < z < 9.0 at%, and- 0.0 at% < a < 1.0 at%, or:- 80.0 at% < x < 95.0 at%,- 2.5 at% < y < 9.0 at%,- 2.5.0 at% < z < 9.0 at%,- 0.0 at% < a < 1.0 at%, and or:- 80.0 at% < x < 95.0 at%,- 2.5 at% < y < 9.0 at%,- 2.0 at% < z < 9.0 at%,- 0.5 at% < a < 1.0 at%, and or:- 85.0 at% < x < 95.0 at%,- 2.5 at% < y < 5.0 at%,- 2.5 at% < z < 5.0 at%,- 0.0 at% < a < 5.0 at%, or:- 85.0 at% < x < 95.0 at%,- 1.5 at% < y < 5.0 at%,- 1.5 at% < z < 5.0 at%,- 2.0 at% < a < 5.0 at%.

[0031] x+y+z+a = 100.0 at% as determined by ICP-OES.

[0032] Optionally Q in the CAM powder according to the disclosure is at least one element of: Al, Mg, Zr, Nb, W, B, Si, Ba, Sr, Ca, Zn, Cr, V, Y, and Ti.

[0033] The CAM powder according to the disclosure may have a Li / M' (at% / at%) ratio of at least 0.95 and at most 1.06, or of at least 0.99 and at most 1.05, or of at most 1.015, or of at least 1.00 and at most 1.01.

[0034] Optionally, the Li / M' (at% / at%) ratio is of at least 1.005 and at most 1.015, or of at least 1.00 or at least 1.009 and at most 1.014, or of 1.012.

[0035] Optionally, the cathode active material of the disclosure may consist ofLi, 0 and M, wherein M consists of Ni, Mn, Co, and Q, wherein each of the elements included in M is present in the CAM in any of above-described contents.

[0036] The cathode active material powder of the disclosure or the secondary particles thereof may have the following formula:LicN i (ioo at%-(y+z+a))MnyCOzQaO2, with :- 80.0 at% < [x = (100 at%-(y+z+a))] < 100.0 at%,- 0.0 at% < y < 9.0 at%,- 0.0 at% < z < 9.0 at%, and- 0.0 at% < a < 1.0 at%,- 0.90 at% < c < 1.10 at%, or 1.00 at% < c < 1.015 at%, or:- 80.0 at% < [x = (100 at%-(y+z+a))] < 95.0 at%,- 2.5 at% < y < 9.0 at%,- 2.5.0 at% < z < 9.0 at%,- 0.0 at% < a < 1.0 at%, and- 0.90 at% < c < 1.10 at%, or 1.00 at% < c < 1.015 at%, or:- 80.0 at% < [x = (100 at%-(y+z+a))] < 95.0 at%,- 2.5 at% < y < 9.0 at%,- 2.0 at% < z < 9.0 at%,- 0.5 at% < a < 1.0 at%, and- 0.90 at% < c < 1.10 at%, or 1.00 at% < c < 1.015 at%, or:- 85.0 at% < [x = (100 at%-(y+z+a))] < 95.0 at%,- 2.5 at% < y < 5.0 at%,- 2.5 at% < z < 5.0 at%,- 0.0 at% < a < 5.0 at%, and- 0.90 at% < c < 1.10 at%, or 1.00 at% < c < 1.015 at%, or:- 85.0 at% < [x = (100 at%-(y+z+a))] < 95.0 at%,- 1.5 at% < y < 5.0 at%,- 1.5 at% < z < 5.0 at%,- 2.0 at% < a < 5.0 at%, and- 0.90 at% < c < 1.10 at%, or 1.00 at% < c < 1.015 at%, or with:- 90.0 at% < [x = (100 at%-(y+z+a))] < 95.0 at%,- 2.5 at% < y < 3.0 at%,- 2.5 at% < z < 3.0 at%,- 0.0 at% < a < 4.0 at%, and- 1.00 at% < c < 1.05 at%, or 1.00 at% < c < 1.015 at%, or even with:- 93.0 at% < [x = (100 at%-(y+z+a))] < 94.0 at%,- 3.0 at% < y < 3.0 at%,- 3.0 at% < z < 3.0 at%,- 0.0 at% < a < 1.0 at%, and- 1.00 at% < c < 1.05 at%. or 1.00 at% < c < 1.015 at%.

[0037] x, y, z, a, and c are determined by ICP-OES.

[0038] The cathode active material powder according to the disclosure may include S in a content of at least 2500 ppm and of at most 3000 ppm.

[0039] The cathode active material powder according to the disclosure may have a BET of at least 0.20 m2 / g and of at most 0.30 m2 / g, or of at least 0.20 m2 / g and of at most 0.25 m2 / g. The term "BET" refers to a specific surface area of the CAM powder that is measured with the Brunauer-Emmett-Teller method. Section D provides the detailed method used in this disclosure.

[0040] The secondary particles of the CAM powder according to the disclosure may be substantially free of void area. The term "void area" refers to a first empty area that is not occupied by a material. The terms "substantially free of void are" refers to a void area percentage that is close to 0.0%, or of at least 0.0 % and at most 10.0%. The void area percentage is a measure of the amount of the first empty area relative to a second predetermined area of a CS-SEM image of a secondary particle, with higher values indicating a higher proportion of void area. The second predetermined area can be referred to as a total area of the secondary particle including the void area within the secondary particle and a matrix area that is an area occupied with material. The void area percentage can also be understood as apercentage of an area of pores included in a secondary particle. The measurement method of the void area is provided in Section H.

[0041] The cathode active material of the disclosure may have a layered structure, for instance, a layered structure of the o-NaFeOz type, or a layered structure of the o-NaFeOz type having a R-3m space group. The (003) peak at around 18.6 degree is usually the particular peak which characterizes the layered structure of R-3 space group.Process for manufacturing the CAM powder

[0042] The second object of the disclosure is a process for manufacturing the CAM powder according to the disclosure comprising:- a 1ststep of providing a powder of a precursor of the cathode active material, the precursor including Ni, Mn, and Co, and comprising secondary particles including a plurality of primary particles having 20.0 < ARPCAM < 25.0,- a 2ndstep of providing a Li source and optionally, at least one Q source, Q being at least one element different than Ni, Mn, and Co,- a 3rdstep of mixing the precursor, the Li source, and optionally the Q source, together to obtain a first mixture. Optionally, the first mixture has a Li (at%) / Ni + Mn+Co+Q (at%) of at least 1.00 and of at most 1.015, and- a 4thstep of subjecting the mixture to a first heat treatment under oxidizing atmosphere at an initial predetermined temperature of at least 400 °C and at most 500 °C, for a duration of at least 4 hours, or at least 5 hours, to at most 6 hours, followed by a second heat treatment under oxidizing atmosphere at a subsequent predetermined temperature of more than 705 °C and at most 715 °C, or from at least 710 °C and at most 715 °C, for a duration of at least 8 hours, or at least 10 hours, to at most 12 hours, or, alternatively, the process includes : a 1ststep of providing a powder of a precursor of the cathode active material, the precursor including Ni, Mn, and Co, and comprising secondary particles including a plurality of primary particles having 25.0 < ARPCAM < 30.0,- a 2ndstep of providing a Li source and optionally, at least one Q source, Q being at least one element different than Ni, Mn, and Co.- a 3rdstep of mixing the precursor, the Li source, and optionally the Q source, together to obtain a second mixture. Optionally, the second mixture has a Li (at%) / Ni + Mn+Co+Q (at%) of at least 1.00 and of at most 1.015, and- a 4thstep of subjecting the mixture to a first heat treatment under oxidizing atmosphere at an initial predetermined temperature of at least 400 °C and at most 500 °C, for a duration of at least 4 hours, or at least 5 hours, to at most 6 hours, followed by a second heat treatment under oxidizing atmosphere at a subsequent predetermined temperature of more than 715 °C, or of at least 720 °C, and at most 725 °C, for a duration of at least 8 hours, or at least 10 hours, to at most 12 hours.

[0043] Alternatively, the process of the disclosure can comprise :- a 1ststep of providing a powder of a precursor of the cathode active material, the precursor including Ni, Mn, and Co, and comprising secondary particles including a plurality of primary particles having 20.0 < ARPCAM < 25.0,- a 2ndstep of providing a Li source and optionally, at least one Q source, Q being at least one element different than Ni, Mn, and Co.- a 3rdstep of mixing the precursor, the Li source, and optionally the Q source, together to obtain a first mixture. Optionally, the first mixture has a Li (at%) / Ni + Mn+Co+Q (at%) of at least 1.00 and of at most 1.015, and- a 4thstep of subjecting the mixture to a first heat treatment under oxidizing atmosphere at an initial predetermined temperature Tii of at least 400 °C and at most 500 °C, for a duration of at least 4 hours, or at least 5 hours, to at most 6 hours, followed by a second heat treatment under oxidizing atmosphere at a subsequent predetermined temperature Tia > Tii , with wherein Tia is of more than 705 °C and at most 715 °C, preferably Tia is of at least 710 °C and at most 715 °C, for a duration of at least 8 hours, or at least 10 hours, to at most 12 hours, or alternatively, the process can include : a 1ststep of providing a powder of a precursor of the cathode active material, the precursor including Ni, Mn, and Co, and comprising secondary particles including a plurality of primary particles having 25.0 < ARPCAM < 30.0,- a 2ndstep of providing a Li source and optionally, at least one Q source, Q being at least one element different than Ni, Mn, and Co.- a 3rdstep of mixing the precursor, the Li source, and optionally the Q source, together to obtain a second mixture, the mixture having optionally a Optionally, the mixture has a Li (at%) / Ni + Mn+Co+Q (at%) of at least 1.00 and of at most 1.015, and- a 4thstep of subjecting the mixture to a first heat treatment under oxidizing atmosphere at an initial predetermined temperature Ti2 of at least 400 °C and at most 500 °C, for a duration of at least 4 hours, or at least 5 hours, to at most 6 hours, followed by a second heat treatment under oxidizing atmosphere at a subsequent predetermined temperature T2a > Ti2 , and T2a = Tia + 10°C, optionally with T2a of more than 715°C, or of at least 720°C, and at most 725°C, for a duration of at least 8 hours, or at least 10 hours, to at most 12 hours.

[0044] Optionally, the process for making the CAM of the disclosure includes :- a 1ststep of providing a powder of a precursor of the cathode active material, the precursor including Ni, Mn, and Co, the precursor comprising secondary particles including a plurality of primary particles having 20.0 < ARPCAM < 25.0,- a 2ndstep of providing a Li source and optionally, at least one Q source, Q being at least one element different than Ni, Mn, and Co.- a 3rdstep of mixing the precursor, the Li source, and optionally the Q source, together to obtain a first mixture, wherein the first mixture has a Li (at%) / (Ni + Mn+Co+Q) (at%) of at least 1.00 and at most 1.015, and a 4thstep of subjecting the mixture to a first heat treatment under oxidizing atmosphere at an initial predetermined temperature Tii of at least 400°C and at most 500°C, for a duration of at least 4 hours to at most 6 hours, followed by a second heat treatment under oxidizing atmosphere at a subsequent predetermined temperature Tia > Tn, for a duration of at least 8 hours to at most 12 hours, wherein Tia is of more than 705 °C and at most 715 °C, or alternatively, the process to make the CAM of the disclosure includes : a 1ststep of providing a powder of a precursor of the cathode active material, the precursor including Ni, Mn, and Co, the precursor comprising secondary particles including a plurality of primary particles having 25.0 <ARPCAM < 30.0,- a 2ndstep of providing a Li source and optionally, at least one Q source, Q being at least one element different than Ni, Mn, and Co.- a 3rdstep of mixing the precursor, the Li source, and optionally the Q source, together to obtain a second mixture, wherein the second mixture has a Li (at%) / (Ni + Mn+Co+Q) (at%) of at least 1.00 and at most 1.015 and- a 4thstep of subjecting the mixture to a first heat treatment under oxidizing atmosphere at an initial predetermined temperature Ti2 of at least 400°C and at most 500°C, for a duration of at least 4 hours to at most 6 hours, followed by a second heat treatment under oxidizing atmosphere at a subsequent predetermined temperature T2a > Ti2 , and T2a = Tia + 10°C, for a duration of at least 8 hours to at most 12 hours.

[0045] In all above-mentioned processes, the precursor may include Ni, Co, and Mn. Contents of Ni, Mn, and Co in CAM can be adjusted by tuning these elements content in the pCAM composition. Li and Q contents in CAM are controlled by adjusting relative content of Li and at least one Q source in the process.

[0046] Alternatively, the precursor may include at least one and at most two of Ni, Co, and Mn, and at least one or at most two of Ni, Co, and Mn source element can be added to the mixture including the pCAM, the Li source and optionally the at least one Q source.

[0047] The aspect ratio of the pCAM is measured according to the analysis method provided in Section G below.

[0048] The pCAM may include M, wherein M comprises Ni, Co and Mn.

[0049] In the method according to the disclosure, the precursor of the CAM can be an oxide, a hydroxide or an oxyhydroxide of M.

[0050] Optionally, the process according to the disclosure includes an additional (fifth) step of sieving the first fired material, thereby obtaining the cathode active material.

[0051] The pCAM according to the disclosure may have a BET of at least 6.0 m2 / g and of at most 7.0 m2 / g, or of at least 6.4 m2 / g and of at most 6.6 m2 / g.

[0052] Various aspects according to the present disclosure are provided in the claims as well as in the specification. The aspects and examples recited in the claims and in the specification are mutually freely combinable unless otherwise explicitly stated.the

[0053] The third object of the disclosure is a battery or a cell including the CAM powder according to the disclosure. The CAM powder is included in an electrode ofthe battery. The battery can be for instance a coin (or button) cell. Section J below provides a non-limitative embodiment of a coin cell. The battery can be a cylindrical, a prismatic or a pouch cell.FiguresFigure 1 : CS-SEM image of a CAM secondary particle according to EXIFigure 2: CS-SEM image of CAM secondary particle according to EX2Figure 3 : CS-SEM image of CAM secondary particle according to EX3Figure 4 : CS-SEM image of pCAM secondary particle according to EXI, EX3, and CEX1Figure 5 : CS-SEM image of pCAM secondary particle according to EX2 and CEX3Figure 6: CS-SEM images of a CAM secondary particle according to CEX1Figure 7: CS-SEM images of a CAM secondary particle according to CEX3 Figure 8: XRD spectrum of EXI CAM showing peaks (108) and (110) Figure 9: XRD spectrum of CEX1 CAM showing peaks (108) and (110)DETAILED DESCRIPTIONEXPERIMENTAL ANALYSIS USED IN THE EXAMPLES AND THE COMPARATIVE EXAMPLES

[0054] The following analysis methods are used in the Examples and the Comparative Example:A) Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) measurement

[0055] The amount of Li, Ni, Co, and Mn in the positive electrode active material powder is measured with the ICP-OES method by using an Agilent ICP 720-ES (Agilent Technologies). 2 grams of powder sample is dissolved into 10 mL of high purity hydrochloric acid (at least 37 wt% of HCI with respect to the total weight of solution) in an Erlenmeyer flask. The flask is covered by a glass and heated on a hot plate at 380 °C until complete dissolution of the precursor. After being cooled to room temperature, the solution of the Erlenmeyer flask is poured into a 250 mL volumetric flask. Afterwards, the volumetric flask is filled with deionized water up to the 250 mL mark, followed by complete homogenization.

[0056] ICP-OES provides wt% of each element included in a material whose composition is determined by this technique. Conversion from wt% to at% is as follows: at% of a first element Ei Eati) in a material can be converted from a given wt% of said first element Ei Ewti) in said material by applying the following formula,wherein Eawi is a standard atomic weight (or molecular weight) of the first element Ei, Ewti is wt% of an ithelement Ei, Eawi is a standard atomic weight (molecular weight) of said ithelement Ei, and n is an integer which represents the number of types of all elements included in the cathode active material.B) Field Emission -Scanning Electron Microscopy (FE-SEM)

[0057] The primary particles or single particles sizes of the cathode active material powder are analyzed by a SEM technique. The measurement is performed with a Thermo Scientific Phenom XL G2 under a high vacuum environment of 9.6xl0'5Pa at 25 °C.

[0058] The SEM field of view is of at least 45 pm x at least 60 pm (i.e. of at least 2700 pm2), optionally of at least 100 pm x 100 pm (i.e. of at least 10,000 pm2). Standalone particles in the image should be well distributed therefore avoiding overlap between particles. This can be achieved by pouring a small amount of the CAM powder sample to an adhesive attached on a SEM sample holder and blowing air to remove an excess of powder.C) Cross section-Scanning Electron Microscopy (CS-SEM) analysisC-l) Cross-section preparation

[0059] The Cross-sections of the positive electrode active material examples and comparative examples as described herein below are prepared by an ion beam cross-section polisher (CP) instrument JEOL (IB-19530CP). The instrument uses argon gas as beam source.

[0060] To prepare the specimen, a small amount of a positive electrode active material powder is mixed with a resin and hardener, then the mixture is heated for 10 minutes on a hot plate. After heating, it is placed into the ion beam instrument for cutting and the settings are adjusted in a standard procedure, with a voltage of 6.5 kV for a 3-hour duration.C-2) Scanning Electron Microscope (SEM) analysis

[0061] The morphology, the primary particle size, aspect ratio, length and thickness, degree of radial orientation, and void area of the positive electrode active material and the precursor are analyzed by using the images from a scanning electron microscopy (SEM) technique. The measurement is performed with a JEOL JSM 7100F under a high vacuum environment of 9.6xl0'5Pa at 25 °C.D) Brunauer-Emmett-Teller (BET) measurement

[0062] The specific surface area is measured with the Brunauer-Emmett-Teller (BET) method using a Micromeritics Tristar 3000. 2g of material powder sample is first dried in an oven at 120 °C for 2h, followed by N2 purging. Then the material is degassed in vacuum at 120 °C for 1 hour prior to the measurement, in order to remove adsorbed species. Specifically, a higher temperature is not recommended in precursor BET measurements, since a precursor may oxidize at relatively high temperature, which could result in cracks or nano-sized holes, leading to an unrealistically high BET. 120 °C is therefore a suitable T°C for CAM and pCAM BET measurement.E) X-ray diffraction (XRD) measurement

[0063] The samples were subjected to XR.D investigations using a laboratory Bruker diffractometer (Cu Ko radiation, A = 1.5418 A) and an airtight sample holder, at room temperature, in the 20 range of 10-80°. FWHM of the peaks observed in the XR.D spectrum indicates a potential amorphization or the formation of nanocrystalline domains when FWHM, in particular of the highest peak, is at least about 1.5°. Furthermore, peaks shift observed between the starting material mixture and the product serve to confirm the formation of a new phase, rather than a simple physical mixture of starting materials.

[0064] The crystallite sizes or crystal sizes of the CAM are calculated from the diffraction angle and the full width at half maximum (FWHM) of the peak of the (108) and (110) planes obtained from the X-ray diffraction pattern using the known Scherrer equation:r: Crystallite size (nm), being the mean size of the ordered (crystalline) domains, which may be smaller or equal to the grain sizeK: Scherrer constant = 0.9A: X-ray wavelength (CuKa = 1.5418 A)6: XRD peak position, one half of 26

[0065] The crystallite size or crystal size of the CAM is calculated from the diffraction angle and the full width at half maximum (FWHM) of the peaks of the (108) and (110) plane (see for instance figure 9 for EXI) obtained from the X-ray diffraction pattern of the CAM powder using above Scherrer equation.

[0066] It is to be noted each of the CAMs according to the disclosure (in EXs and CEXs) exhibits a peak of the (110) plane that is observed at (around) 64.82±1° and a peak of the (108) plane (that can also be referred to as (018) plane) that is observed at (around) 64.43±1°, these peaks being assigned to a crystal structure having a space group R-3m or R3m (see figure 8 and 9 for EXI).

[0067] Article from Fangkun Li published in 2020 in Nanomaterials: "Ni-Rich Layered Oxide with Preferred Orientation (110) Plane as a Stable Cathode Material for High-Energy Lithium-Ion Batteries", 10, 2495 (doi : 10.3390 / nanol0122495) explains that Li diffusion of NMC CAM can be improved by optimizing (110) facet orientation of CAM. In particular, this article teaches that the ratio 1(110) / I(108) of XRD peak intensity (I) should be of more than 1.0 to achieve above-mentioned effect.

[0068] The (110) crystal plane is defined as lying within the a-b plane of a(n) (hexagonal) unit cell of the crystal structure, while the (108) crystal plane is defined as comprising contributions from both a-b plane and the c-axis of the (hexagonal) unit cell, thereby representing a composite crystallographic direction.

[0069] The respective size of each of the two crystal planes drives the electro chemical properties of the NMC CAM.

[0070] On one hand, the (110) plane size is indicative of a first (open layered) interspace spacing between (Ni, Co, Mn, Q)O2 slabs along the c-axis of the hexagonal unit cell. The longer the 1stinterspace distance, the more efficient Li+ions (de)intercalation (or Li ion pathways creation) along c-axis (from bulk to surface of CAM particles).

[0071] However, if the interspace distance is too long, this leads to an increase of the risk of crystal structure defect formation (e.g. increasing fraction of Ni atoms positioned on Li atoms site in the structure), thereby altering the Li ions pathways and ultimately causing structural degradation of the primary particle during repeatedcharge and discharge cycles. The (110) plane size drives aspect ratio of the primary particle, the larger the size, the higher the aspect ratio. Too high aspect ratio is therefore an indicator of above-mentioned issues.

[0072] On the other hand, the (108) plane size is indicative of a second interspace distance between (Ni, Co, Mn, Q)O2 slabs along the a-axis of the unit cell.

[0073] Whereas the (110) plane has an open layered interspace for Li ion transport, for the (108) plane, the Li, Ni, Co, Mn, O, and optionally Q atoms are densely packed and no straight channel is observed on this plane.

[0074] Therefore, the longer this 2ndinterspace distance, the less densely packed the (Ni, Co, Mn, Q)O2 slabs along the a-axis, thereby allowing creation of alternative a-axis Li ion channels compensating above-mentioned alteration of c-axis channels.

[0075] Thus, optimizing the (110) / (108) ratio (along with aspect ratio) is crucial for achieving balanced lithium-ion transport, structural stability, and improved electrochemical performance of (v)hNMC cathode materials.F) Degree of radial orientation calculation method

[0076] The below provided calculation method is documented in US'240.

[0251] of US'240 describes that the degree of radial orientation (DRO) means an average angle consisting of an angle value obtained by measuring several angles between a reference line (RFL) and a particle orientation line (POL) and by calculating an average value of measured angles.The reference line is a (virtual) line connecting: i. a first geometric centre (also called centroid) of a first closed two-dimensional (or plane) shape of a secondary particle having a first perimeter defined by an edge of a first cross-section of a secondary particle CS-SEM image, the secondary particle includes a set of several of primary particles and the CS- SEM image of the secondary particle includes several second closed plane shapes, each of the closed plane shapes having a second perimeter defined by an edge of a second cross-section of a primary particle of the set of several primary particles, andi i . a second centroid of a second closed plane shape related to a primary particle of the secondary particle, the primary particle being provided at an outermost portion of the first shape of the secondary particle.The RFL is therefore a virtual line connecting a first centroid of a CS-SEM image of a cross-section of a secondary particle and a second centroid of a cross-section of a primary particle in the CS-SEM image, the primary particle being a part of an outermost portion the secondary particle. The outermost portion is a portion of the first cross-section of the secondary particle CS-SEM image wherein the longest straight-lined distance between the first centroid associated to the secondary particle and the second centroid of the primary particle is measured.The particle orientation line is a (virtual) line penetrating the centroid of the primary particle cross section in the CS-SEM image and extending in parallel to an orientation direction of the primary particles. The orientation direction of the primary particle corresponds to a vector oriented along the longest length (L) of the primary particle. L is a straight-lined or rectilinear (and therefore shortest measurable) distance separating two outermost points located on the perimeter of the primary particle cross sectional SEM image. o is a smallest angle measured in degree (°) at a single intersection point of the RFL and POL. o / corresponds to a degree of radial orientation of a primary particle / . The intersection point is the centroid of the centroid of the primary particle cross section in the SEM image of the secondary particle.A G(ORFL-POL) or ARO corresponds to an average degree of radial orientation of primary particles of a secondary particle.wherein n = at least 30.AVG(o) or ARO is calculated by using Image J software (ImageJ 1.52a, National Institutes of Health, USA) and a protocol is provided here below.

[0077] As mentioned above, the average degree of radial orientation of primary particles are calculated by using Image J software (ImageJ 1.52a, National Institutesof Health, USA). The measurement in this disclosure is performed according to the following descriptions:Step 1) Open the file containing CS-SEM image of positive electrode active material with 5,000 times magnification and sufficient contrast.Step 2) Set scale according to the CS-SEM magnification.Step 3) Pick 'Area' box in the 'Select measurement'.Step 4) Select 'Angle tool' and select 1stpoint which is the center point (or geometric center) of a secondary particle and then select 2ndpoint which is the center point (or geometric center) of a primary particle provided at the outermost portion of the secondary particle to draw a first reference line.Step 5) Draw a second reference line which is a longest length or diameter (L) of the primary particle penetrating the 2ndpoint and select the 3rdpoint which is the edge point of the 2ndreference line closer to the 1stpoint.Step 6) Select 'Analyze' and 'Measure' to measure the degree of radial orientation.Step 7) Repeat Step 4~6) for at least 30 primary particles.Step 8) Save the image as JPEG.Step 9) Average the angle values of randomly selected primary particles.G) Aspect ratio analysis

[0078] The aspect ratio (AR) is an averaged U / D of at least 20 primary particles and L and D are expressed in pm and measured based a on a CS-SEM image of primary particles.

[0079] The L / D ratio corresponds to a ratio between : i. L that is the longest length (in pm) of the primary particle and ii. D that is the shortest width (in pm) of the primary particle. D is also referred to as the thickness t of a primary particle.L is a straight-lined or rectilinear (and therefore longest measurable) distance separating two outermost points located on the perimeter of the primary particle cross sectional SEM image. D is a straight-lined or rectilinear (and therefore shortest measurable) distance separating two nearest points located on the perimeter of the primary particle cross sectional SEM image. The width or L is perpendicular to L.wherein n' = at least 20.AR can be calculated by using Image J software (ImageJ 1.52a, National Institutes of Health, USA) and a protocol is provided here below:

[0080] The aspect ratio of primary particles is calculated based on a CS-SEM image of primary particles by using Image J software (ImageJ 1.52a, National Institutes of Health, USA) according to the following steps:Step 1) Open the file containing CS-SEM image of positive electrode active material with 5,000 times magnification and sufficient contrast.Step 2) Set scale according to the CS-SEM magnification.Step 3) Pick 'Area box' in the 'Select measurement'.Step 4) Select freehand selection and draw one primary particle and measure individual primary particle.Step 5) Save the measurement value of major for L and minor for D.Step 5) Repeat step 4 at least 20 and at most 30 primary particles.Step 6) Save the image as JPEG.Step 7) Calculate the aspect ratio of the individual primary particles using major value for L and minor value for D (or t).In this section G), the primary particles belong either to a CAM or a pCAM secondary particle.H) Void Area analysis

[0081] The void area or core porosity of a CAM corresponds to (A2 / Al)*100, wherein :- A2 is a total area (measured in pm2) of plane shaped pores measured in a CS-SEM image of a secondary particle of the CAM, and- Al is a total area (measured in pm2) of a plane closed shape having a perimeter defined by an edge of a CS-SEM image of the secondary particle of the CAM.US patent 11476460 provides a similar definition as the above one, in column 25, lines 33 to 38.A2 and Al can be measured by using Image J software (ImageJ 1.52a, National Institutes of Health, USA) and a protocol is provided here below.

[0082] The void area or core porosity of the CAM secondary particles are calculated by using ImageJ software (ImageJ 1.52a, National Institutes of Health, USA) according to the following steps:Step 1) Open the file containing SEM image of positive electrode active material with 5,000 times magnification and sufficient contrast.Step 2) 'Set scale' according to the SEM magnification.Step 3) Pick 'Area' box in the 'Select measurement'.Step 4) Select 'polygon tool' and select the outer edge of particle then click 'Analyze' - 'Measure' to get the area of a whole particle (Al). Equivalent radius of particle (R.1) is obtained by assuming the particle in the spherical shape following the below equation:Step 5) In the selected image, select 'Edit'-'Clear Outside' to remove the outer part of particle.Step 6) Select 'Process' - 'Binary' - 'Make Binary' to convert the cropped image to be a binary black and white image.Step 7) Save the image as .tiff.Step 8) Select 'Analyze' - 'Analyze particle' to obtain the area of black regions which are the pores of core. Total area is total pores area of core (A2).Core void area or core porsosity is calculated according to:I) Particle size distribution (PSD) analysis

[0083] The particle size distribution (hereafter referred to as PSD) of the positive electrode active material is measured by laser scattering method using a Malvern Mastersizer 3000 with a Hydro MV wet dispersion accessory after having dispersed each of the powder samples in an aqueous medium. In order to improve the dispersion of the powder, sufficient ultrasonic irradiation and stirring are applied, and an appropriate surfactant is introduced. PSD may be represented by D50 or avg,both defined as the particle size at 50 % of the cumulative volume% distributions, respectively, obtained from the Malvern Mastersizer 3000 with Hydro MV measurements.J) Coin cell TestingJ-l) Coin cell preparation

[0084] For the preparation of a positive electrode, a slurry that contains a positive electrode active material powder, conductor (Super P, Timcal), binder (KF#9305, Kureha) - with a formulation of 96.5: 1.5:2.0 by weight - in a solvent (NMP, Mitsubishi) is prepared by a high-speed homogenizer. The homogenized slurry is spread on one side of an aluminium foil using a doctor blade coater with a 170 pm gap. The slurry coated foil is dried in an oven at 120 °C and then pressed using a calendaring tool. Then it is dried again in a vacuum oven to completely remove the remaining solvent in the electrode film. A coin cell is assembled in an argon-filled glovebox. A separator (Celgard 2320) is located between a positive electrode and a piece of lithium foil used as a negative electrode. IM LiPF6 in EC / DMC (1 :2) is used as electrolyte and is dropped between separator and electrodes. Then, the coin cell is completely sealed to prevent leakage of the electrolyte.J-2) Testing Method

[0085] The testing method is a conventional "constant cut-off voltage" test. The conventional coin cell test in the present disclosure follows the schedule shown in Table 1. Each cell is cycled at 25 °C using a Toscat-3100 computer-controlled galvanostatic cycling station (from Toyo).

[0086] The initial discharge capacity (DQ1), discharge capacity after the 34thcycle (DQ34), and discharge capacity after the 35thcycle (DQ35) are measured in constant current mode (CC) at C rate of 0.1C in voltage range from 4.3 V to 3.0 V. The schedule uses a 1C current definition of 200 mA / g in the 4.3V to 3.0V / U metal range. The first cycle is evaluated at 0.1C.

[0087] The schedule uses a 1C current definition of 220 mA / g in the 4.3 V to 3.0 V / Li metal window range. The capacity fading rate (QF01C) is obtained according to the following equation below: 100QF01C(% / cycle) = 100 —Table 1 : cycling schedule for coin cell testing methodEXAMPLES AND COMPARATIVE EXAMPLES

[0088] The present disclosure is further illustrated in the following examples and comparative examples.

[0089] All the below CAM powder examples in scope of the disclosure are manufactured according to this process:1) A Nio.94Mno.o3Coo.o3(OH)2 precursor powder, having a primary particles aspect ratio (ARPCAM) of at least 20.0 and at most 30.0 is mixed with LiOH to obtain a mixture, the mixture has a Li (at%) / Ni + Mn+Co+Q (at%) of at least 1.00 and at most 1.015 (with Q = 0 at%),2) the mixture is firstly heat treated under oxygen atmosphere at an initial predetermined temperature (Ti) of at least 400 °C and at most 500 °C, for a duration of at least 4 hours to at most 6 hours, followed by a second heat treatment under oxidizing atmosphere at a subsequent predetermined temperature (T2): i. of more than 705 °C, preferably of at least 710 °C, and at most 715 °C, for a duration of at least 8 hours to at most 12 hours if pCAM has an AR. between 20.0 and 25.0,ii. or of more than 715 °C, preferably of at lest 720 °C, and at most 725 °C, for a duration of at least 8 hours to at most 12 hours if pCAM has an AR. of more than 25.0 and of at most 30.0.

[0090] pCAM, CAM and process parameters, as well as EC performances are summarized in Tables 2, 3, and 4. Table 2 summarizes relationship between claimed feature and process-related parameters.

[0091] A positive electrode active material CEX1 having an AR (A CAM) of 3.32 and a (110) / (108) ratio of 0.96 is obtained through following steps:1) First mixing : 165 grams of Nio.94Mno.o3Coo.o3(OH)2 having an aspect ratio of 29.7, and 43.43 grams of LiOH are mixed homogeneously to prepare a first mixture. The Li over (Ni + Mn+Co) at% ratio is of 1.005.2) First heating : The first mixture is heated at a first temperature of 455 °C (Ti) for 5 hours (1stduration - di), and the first temperature is raised up to a second temperature of 730 °C (T2) for additional lOh (2ndduration - d2). The heating is performed during 15 hours under oxygen atmosphere and is followed by cooling and sieving to prepare the cathode active material powder. The sieving was performed using a 270-mesh sieve. ositive electrode active material EXI is prepared according to the CEX 1 except that T2 = 720 °C, and Li / M ratio indicated in of Table

[0093] A positive electrode active material EX2 is prepared according to the same method as CEX1 except that a Nio.94Mno.o3Coo.o3(OH)2 having an aspect ratio of 24.2 is used in step 1) to prepare the first mixture. In EX2, T2 = 710 °C, and Li / M ratio indicated in of Table 5d.

[0094] A positive electrode active material CEX2 is prepared according to the same method as EX2 except that T2 = 720 °C, and Li / M ratio indicated in of Table 5d.

[0095] A positive electrode active material CEX3 is prepared according to the same method as EX2 except that Tz = 700 °C, and Li / M ratio indicated in of Table 5d.

[0096] A positive electrode active material is prepared according to the same method as EX2 except that T2 = 680 °C, and Li / M ratio indicated in of Table 5d.

[0097] A positive electrode active material CEX5 is prepared according to the same method as EXI except that a Nio.94Mno.o3Coo.o3(OH)2 having an aspect ratio of 10.1 was used to prepare the first mixture, and Li / M ratio indicated in of Table 5d.

[0098] A positive electrode active material CEX6 is prepared according to the same method as EXI except that a Nio.94Mno.o3Coo.o3(OH)2 having an aspect ratio of 5.2 was used to prepare the first mixture, and Li / M ratio indicated in of Table 5d.

[0099] A positive electrode active material CEX7 is prepared according to the same method as EXI except that a Nio.94Mno.o3Coo.o3(OH)2 having an aspect ratio of 3.1 was used to prepare the first mixture, and Li / M ratio indicated in of Table 5d.

[0100] A positive electrode active material EX3 is prepared according to the same method as EXI, and Li / M ratio indicated in of Table 5d.

[0101] A positive electrode active material CEX8 is prepared according to the same method as EX2 except that T2 = 705 °C, and Li / M ratio indicated in of Table 5d.

[0102] A positive electrode active material CEX9 is prepared according to the same method as EXI, and Li / M ratio indicated in of Table 5d.

[0103] Tables 2 to 5 provide a summary of CAM key- para meters for EXs and CEXs according to the disclosure.

[0104] Each of the (110) and (108) crystal planes corresponds to a distinct crystallographic direction (a-b plane and c-axis, respectively). Therefore, the (110) / (108) ratio is an indicator of the crystal structure anisotropy.

[0105] In the present disclosure, a (110) / (108) ratio of at most 0.95 means relatively high anisotropy, suggesting preferential crystallite growth along a specific direction (c-axis). Conversely, CAMs of CEXs with (relatively) high (110) / (108) ratios (e.g., a ratio of more than 0.95) exhibit relatively lower anisotropy (or relative high isotropy of their crystal structure).

[0106] In the framework of the present disclosure, it has been found that CAM having a (110) / (108) ratio < 0.90 (related to a relatively high crystal structure anisotropy) and an AR of < 0.4 cannot be synthetized according to any of the two- step firing manufacturing routes (illustrated in Tables 5a & b).

[0107] More specifically, starting from a pCAM having: 25.0 < A PCAM < 30.0, and in order to achieve a CAM having an AR value of more than 5.5, T2 must be higher than 725 °C. However, if T2 > 725 °C, then crystal structure will grow along c-axis so that the (110) / (108) ratio will be higher than 0.90. Therefore, a CAM having both (110) / (108) ratio < 0.90 and an AR < 4.0 cannot be synthetized.

[0108] Similarly, starting from a pCAM having: 20.0 < A PCAM s 25.0, and in order to achieve a CAM having an AR value of less than 4.0, T2 must be lower than 715 °C. However, if T2 < 715 °C, then crystal structure will grow along c-axis so that the (110) / (108) ratio will be lower than 0.90.

[0109] These two case-scenarios are flagged as CEX10 in the present disclosure.able 2a: pCAM, CAM, and process-related parameters of EXS and CEXsavgPcAM: D50 of pCAM (expressed in pm) * L: length of pCAM primary particle; t: thickness of pCAM primary particle (L and t are expressed in nm)able 2b: CAM AR. and (110) / (108) of EXS and CEXs vs claimed values4.0 < ARCAM < 5.5, and 0.90 < (110) / (108) < 0.95able 3: CAM properties of EXs and CEXsARO: averaged degree of radia orientation *avgcAM: D50 of CAM (expressed in pm) ** (110) : (110) peak (range) crystallite size calculated by Scherrer equation ** (108) : (108) peak (range) crystallite size calculated by Scherrer equationTable 4: CAM EC performances of EXs and CEXsTables 5a, b, c, and d : summary of the disclosure and the processes related thereto5b5d*M = Ni + Mn+Co+Q (at%) in the first or second mixture

[0110] The pCAM of EXs and CEXs are manufactured according to the following general protocol :1) An aqueous solution of Me including nickel, cobalt, and manganese sulfate as raw materials in a relative mol% ratio of 94.0: 3.0: 3.0 is prepared and labeled Pl. Me concentration in Pl solution is 2.0 mol / L.2) An alkaline solution of NaOH is prepared at a 10.0 mol / L concentration. This alkaline solution is labeled P2.3) A complexing agent solution P3 is prepared by incorporating NH3 (hereafter referred to as ammonia) to deionized water, so as to obtain a P3 ammonia solution at a concentration of 5.0 mol / L.4) A reaction kettle is preloaded with seed crystals at a solid content of 150.0 g / L, the seeds having an average size of between 1.0 and 5.0 pm.5) The Pl, P2, and P3 solutions were added dropwise into the reaction kettle, thereby obtaining a slurry stirred at a speed of around 600 rpm (rotation per minute).6) Reaction conditions in the kettle are as follows: i. a temperature in the kettle (reaction temperature) is set at 60.0 °C (Teo), ii. a predetermined pH (measured at 25.0 °C) value pHPthat is included in a range from 10.0 to 14.0,

[0111] a predetermined ammonia concentration NH3Pthat is included in a range from 0.50 mol / L to 0.90 mol / L, and N2 gas is injected at a flow rate of 50 ml / min. The feeding speed of the Pl to P3 solutions is controlled so that it is set to 0 ml / sec (e.g., feeding is stopped) when average size of particle in the slurry reaches a predetermined value Savg. Savg i s determined so as to achieve any of the avgpcAM provided in Table 2.1) The slurry is then discharged into an aging kettle, Teo, pHPand NHsPconditions are maintained in the aging kettle. In the aging kettle, the slurry is subjected to a rotation speed of around 300 rpm. The slurry stayed in the aging kettle during a period of at least 10 hours.2) The slurry is then washed with deionized water.

[0112] A PCAM of Table 2 can be achieved by adjusting a combination of pHPand NH3Pas follows:For instance, a desired ARPCAM value can be attained by increasing a predetermined pH value of the slurry from 10.0 to 14.0 and simultaneously by decreasing predetermined ammonia concentration in the slurry from 0.90 to 0.50 (mol / L).

[0113] Data provided in Tables 1 to 4 demonstrate that lower QF01C and higher DQ1 are achieved with CAM powders having claimed ARCAM and (110) / (108) ratio, e.g. :ARCAM = 4.14 and 4.18(110) / (108) = 0.92.These features are unique and achieved by peculiar process conditions that are summarized in Table 5.

[0114] In particular, it is observed that a CAM powder having an AR of about 4.20 ± 0.10 can be achieved with two-step heat treatment of pCAM powder satisfying any of the following requirements:- pCAM having an ARPCAM about 30.0 undergoes a two-step heating treatment at Ti (Ti2) = 455 °C and at T2 (T2a) = 720 °C, or:- pCAM having an ARPCAM about 24.0 undergoes a two-step heating treatment at Ti ( i ) = 455 °C and at T2(Tia) = 710 °C.

[0115] A pCAM having a high aspect ratio (i.e., of at least 20.0) of primary particles has to be used along with appropriate heat treatment temperatures to achieve a desirable aspect ratio of CAM's primary particles.

[0116] It has to be noticed that ARO of CAM particles according to the disclosure can be lower can substantially deviate from 0° w / o necessarily impairing key electrochemical parameters as supported by data in Tables 3 and 4.

[0117] Whereas CAM of the disclosure can only be achieved with conditions provided in Tables 5a to d, especially with a Li / M ratio of no more than 1.015

[0118] While this disclosure describes several examples, it will be understood by those skilled in the art that various changes can be made, and equivalents can be substituted for elements thereof without departing from the scope of the disclosed examples. In addition, many modifications can be made to adapt a particular situation or material to the teachings of this disclosure without departing from the scope thereof. Therefore, it is intended that this disclosure is not limited to the particular examples disclosed as the best mode contemplated for carrying out this disclosure. It should also be understood that the examples disclosed herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of featuresor aspects of each example should be considered as available for other similar features or aspects of other examples.

Claims

CLAIMS1. A cathode active material powder comprising Li, M' and oxygen, wherein M' has a formula : NixMnyCozQa, Q being another element than Ni, Mn, and Co, wherein:- 80.0 at% < x < 95.0 at%,- 2.5 at% < y < 9.0 at%,- 2.5 at% < z < 9.0 at%, and- 0.0 at% < a < 1.0 at%, with x+y+z+a = 100.0 at% as determined by ICP-OES, the cathode active material powder comprising secondary particles including a plurality of primary particles, wherein the primary particles have an aspect ratio of at least 4.0 and of at most 5.5, or of at least 4.0 and of at most 5.0, or of at least 4.0 and of at most 4.8, wherein the cathode active material has a crystal size ( 110) / ( 108) ratio of at least 0.90 and of at most 0.95, or of at least 0.90 and of at most 0.93, or of at least 0.90 and of at most 0.92, as measured by XR.D.

2. The cathode active material powder according to claim 1, wherein:- 90.0 at% < x < 95.0 at%,- 2.5 at% < y < 3.0 at%,- 2.5 at% < z < 3.0 at%, and- 0.0 at% < a < 4.0 at%.

3. The cathode active material powder according to claim 1 or 2, wherein Q is at least one element of: Al, Mg, Zr, Nb, W, B, Si, Ba, Sr, Ca, Zn, Cr, V, Y, Sb, Ta, Mo, and Ti.

4. The cathode active material powder according to any of the preceding claims, wherein the aspect ratio is of at most 4.5, or of at most 4.2.

5. The cathode active material powder according to any of the preceding claims, having a Li / M' (at% / at%) ratio of at least 1.00 or at least 1.005 and at most 1.015, or of at least 1.009 and at most 1.014, or of 1.012.

6. The cathode active material powder according to any of the preceding claims, wherein the primary particles have an averaged degree of radial orientation of at least 15.0° and of at most 35.0°.

7. The cathode active material powder according to any of the claims 1 to 5, wherein the primary particles have an averaged degree of radial orientation of at least 20.0° and of at most 25.0°.

8. The cathode active material powder according to any of the preceding claims, comprising S in a content of at least 2500 ppm and of at most 3000 ppm.

9. The cathode active material powder according to any of the preceding claims, having a BET of at least 0.20 m2 / g and of at most 0.30 m2 / g, or of at least 0.20 m2 / g and of at most 0.25 m2 / g.

10. The cathode active material powder according to any of the preceding claims, wherein the secondary particles are substantially free of void area.

11. The cathode active material according to any of the preceding claims, suitable for Li-ion secondary batteries.

12. The cathode active material according to any of the preceding claims, having a formula:LicNi(i-(y+z+a))MnyCOzQaO2, with :- 80.0 at% < [x = (100 at%-(y+z+a))] < 95.0 at%,- 2.5 at% < y < 9.0 at%,- 2.5.0 at% < z < 9.0 at%,- 0.0 at% < a < 1.0 at%, and- 1.00 at% < c < 1.015 at%, wherein:

13. A battery comprising the cathode active material according to any of the preceding claims.

14. An electric vehicle comprising the battery according to claim 13.

15. A process for manufacturing the cathode active material powder according to any of claims 1 to 12, comprising :- A first step of providing a powder of a precursor of the cathode active material, the precursor including Ni, Mn, and Co, the precursor comprising secondary particles including a plurality of primary particles having 20.0 <ARPCAM < 25.0,- a second step of providing a Li source and optionally, at least one Q source, Q being at least one element different than Ni, Mn, and Co.- a third step of mixing the precursor, the Li source, and optionally the Q source, together to obtain a first mixture, wherein the first mixture has a Li (at%) / (Ni + Mn+Co+Q) (at%) of at least 1.00 and at most 1.015, and- a fourth step of subjecting the mixture to a first heat treatment under oxidizing atmosphere at an initial predetermined temperature Tii of at least 400°C and at most 500°C, for a duration of at least 4 hours to at most 6 hours, followed by a second heat treatment under oxidizing atmosphere at a subsequent predetermined temperature Tia > Tn, for a duration of at least 8 hours to at most 12 hours, wherein Tia is of more than 705°C and at most 715°C, or: a first step of providing a powder of a precursor of the cathode active material, the precursor including Ni, Mn, and Co, the precursor comprising secondary particles including a plurality of primary particles having 25.0 <ARPCAM < 30.0,- a second step of providing a Li source and optionally, at least one Q source, Q being at least one element different than Ni, Mn, and Co.- a third step of mixing the precursor, the Li source, and optionally the Q source, together to obtain a second mixture, wherein the second mixture has a Li (at%) / (Ni + Mn+Co+Q) (at%) of at least 1.00 and at most 1.015 and- a fourth step of subjecting the mixture to a first heat treatment under oxidizing atmosphere at an initial predetermined temperature Ti2 of at least400°C and at most 500°C, for a duration of at least 4 hours to at most 6 hours, followed by a second heat treatment under oxidizing atmosphere at a subsequent predetermined temperature T2a > Ti2 , and T2a = Tia + 10°C, for a duration of at least 8 hours to at most 12 hours.

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