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

Abstract

The present disclosure provides a cathode active material powder suitable for Li-ion secondary batteries, comprising Li, M, and O, wherein M includes: - Ni in a content x, with 85.0 at% ≤ x < 100.0 at% relative to M, - Mn in a content y, with 0.0 at% ≤ y ≤ 5.0 at% relative to M, - Co in a content z, with 0.0 at% ≤ z ≤ 5.0 at% relative to M, - Ce in a content a, with 0.0 at% < a ≤ 3.0 at% relative to M, - Zr in a content b, with 0.0 at% < b ≤ 1.0 at% relative to M, and - D in a content c, with 0.0 at% < c ≤ 1.0 at% relative to M, wherein D is an element different than Ni, Mn, Co, Ce and Zr, the cathode active material powder comprising particle comprising at least one primary particle and at most twenty primary particles.

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. In the present disclosure, 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 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 very high content of Ni, hereafter referred as vhNMC. For instance, a vhNMC CAM comprises a Ni / (Ni + Mn+Co) ratio of more than 80.0 at%. 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, including therefore the use of the lithium ion battery including the CAM of the disclosure in an 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 vhNMC CAMs are 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, this disclosure concerns vhNMC CAM powders comprising- standalone (secondary) particles including at least one primary particle and at most twenty primary particles. Optionally, each of the standalone particles include at least one primary particle and at most twenty primary particles, and- the powder has a DSEM / D50 ratio of at least 0.60, wherein D50 is a volumetricbased median particle size or a predefined particle size at 50% of a cumulative volume % distribution of standalone particles in the CAM powder and DSEM is the average primary particle size of the standalone secondary particles.

[0008] Such CAM powders are known, for instance from : US 2021 / 0143423 (hereafter referred to as US'423) that discloses a process for manufacturing a powder including standalone particles having a D50 of at least 2.0 pm and at most 8.0 pm, and a span (defined as D90-D10 / D5, wherein DIO and D90 are defined as a predefined particle size at respectively 10% and 90% of the cumulative volume % distribution of standalone particles in the CAM powder.

[0009] This type of particles can be called either "monolithic" or "single" particle when the standalone particle consists of one primary particle, or "semi monolithic" particle when the standalone particle includes more than one and at most twenty primary particles. A CAM powder having single standalone particles can be referred to as a monolithic morphology CAM. A CAM powder having semi monolithicstandalone particles or includes a combination of single and semi monolithic standalone particles can be referred to as a CAM having a semi monolithic morphology.

[0010] Advantages of a CAM powder comprising monolithic or semi monolithic particles are described in US'423, in

[0016] to

[0018] :- Safety: (semi) monolithic particles-based CAM allow to achieve improved safety, for instance with respect to CAM including polycrystalline particles,- Packaging density: the (semi) monolithic particles allow a dense CAM powder packing, and- Mechanical strength: the (semi) monolithic particles can better withstand mechanical strains caused by volume change during cycling in a battery.

[0011] According to US'423, the D50 and span of the (semi) monolithic particles are critical design parameter driving above-mentioned advantages.

[0012] For instance, US'423 warns that for small D50 values (e.g. D50 of about 3.0 pm), safety of CAM powder including (semi) monolithic particles may deteriorate, mainly due to increasing specific surface area. Whereas it is declared in US'423 that 2.0 pm < D50 < 8.0 pm is optimal for automotive battery- related applications, safety improvement is still required for CAM powder designs exploring a low side of the above-mentioned D50 range (e.g. D50 2.0 pm < D50 < 4.0 pm), especially for vhNMC CAM compositions wherein safety issues may be exacerbated due to the (relative) very high at% of Ni.

[0013] CN118117075 (CN'075) discloses several positive electrode active materials (e.g., EXs 1 to 4 and EX9) having non-monolithic morphology.

[0014] A CAM powder having a monolithic morphology differs from those having a polycrystalline morphology in that: i. it includes (standalone) secondary particles comprising no more than twenty primary particles, and ii. it has a DSEM / D50 ratio of at least 0.60.For instance, CN117878265 (CN'265) discloses CAM powders having a non- monolithic morphology with a DSEM / D50 of less than 0.60.

[0015] Therefore, it is a first object of the present disclosure to provide a vhNMC CAM having semi (monolithic) allowing to achieve improved safety when used in a battery.

[0016] A second object of the disclosures includes a process for manufacturing the CAM according to the disclosure.

[0017] A third object of the disclosure relates to a battery including the CAM according to the disclosure.

[0018] A fourth object of the disclosure covers an EV or a HEV including the battery according to the disclosure.SUMMARY OF THE DISCLOSURE

[0019] The first object of the disclosure is achieved by providing a cathode active material powder according to claim 1, comprising Li, M, and 0, wherein M includes :- Ni in a content x, with 80.0 at% < x < 100.0 at% or 85.0 at% < x < 100.0 at%, or 85.0 at% < x < 95.0 at%, or 90.0 at% < x < 95.0 at%, relative to M,- Mn in a content y, with 0.0 at% < y < 7.5 at%, or 0.0 at% < y < 5.0 at%, 0.0 at% < y < 2.5 at%, or 0.0 < y < 1.5 at%, or 0.0 < y < 1.0 at% relative to M,- Co in a content z, with 0.0 at% < z < 7.5 at%, or 0.0 at% < z < 5.0 at%, or 2.5 at% < z < 5.0 at%, or 4.0 at% < z < 5.0 at% relative to M,- Ce in a content a, with 0.0 at% < a < 3.0 at%, or 0.0 at% < a < 1.0 at%, or 0.05 at% < a < 0.15 at%, or 0.10 at% < a < 0.15 at% relative to M,- Zr in a content b, with 0.0 at% < b < 1.0 at%, or 0.05 at% < b < 0.50 at%, or 0.10 at% < b < 0.15 at% relative to M, and- D in a content c, with 0.0 at% < c < 1.0 at%, or 0.0 at% < c < 0.75 at%, or 0.0 at% < c < 0.50 at%, or 0.25 at% < c < 0.50 at% relative to M, wherein D is an element different than Ni, Mn, Co, Ce and Zr, wherein x+y+z+a + b = 100.0 at%, x, y, z, a, b, and c being measured by ICP-OES, the cathode active material powder comprising (standalone) particles comprising at least one primary particle and at most twenty primary particles, the cathode active material powder having a DSEM / D50 ratio of at least 0.60.

[0020] Optionally, each of the (standalone) particles includes at least one primary particle and at most twenty primary particles.

[0021] The CAM powder is suitable for Li-ion secondary batteries.

[0022] It is indeed observed that limited bulging is achieved for a battery including the CAM according to claim 1, as illustrated by examples of the present disclosure.

[0023] The present disclosure includes the following aspect:CAM powder

[0024] In the present disclosure, the particle comprising the primary particles can be a standalone particle.

[0025] The CAM powder of the disclosure may have a DSEM / D50 ratio of at least 0.80, or of at least 0.85.

[0026] Optionally :0.600 < DSEM / D50 < 1.00, or- 0.600 < DSEM / D50 < 0.95.

[0027] The disclosure may also include a CAM powder wherein the standalone particles include Li, M, and O, wherein M includes :- Ni in a content x, with 80.0 at% < x < 100.0 at% or 85.0 at% < x < 100.0 at%, or 85.0 at% < x < 95.0 at%, or 90.0 at% < x < 95.0 at%, relative to M,- Mn in a content y, with 0.0 at% < y < 7.5 at%, or 0.0 at% < y < 5.0 at%, 0.0 at% < y < 2.5 at%, or 0.0 < y < 1.5 at%, or 0.0 < y < 1.0 at% relative to M,- Co in a content z, with 0.0 at% < z < 7.5 at%, or 0.0 at% < z < 5.0 at%, or 2.5 at% < z < 5.0 at%, or 4.0 at% < z < 5.0 at% relative to M,- Ce in a content a, with 0.0 at% < a < 3.0 at%, or 0.0 at% < a < 1.0 at%, or 0.05 at% < a < 0.15 at%, or 0.10 at% < a < 0.15 at% relative to M,- Zr in a content b, with 0.0 at% < b < 1.0 at%, or 0.05 at% < b < 0.50 at%, or 0.10 at% < b < 0.15 at% relative to M, and- D in a content c, with 0.0 at% < c < 1.0 at%, or 0.0 at% < c < 0.75 at%, or 0.0 at% < c < 0.50 at%, or 0.25 at% < c < 0.50 at% relative to M, wherein D is an element different than Ni, Mn, Co, Ce and Zr, wherein x+y+z+a+b = 100.0 at%, x, y, z, a, b, and c being measured by ICP-OES or EDX (energy-dispersive X-ray spectroscopy).

[0028] Optionally:- Ni is present in a content x: 90.0 at% < x < 95.0 at% relative to M,- Mn is present in a content y: 0.5 at% < y < 2.0 at% relative to M,- Co in a content c: 4.4 at% < z < 6.0 at% relative to M,- Ce is present in the CAM in a content a : 0.05 at% < a < 0.50 at% relative to M,- Zr is present in the CAM in a content b : 0.05 at% < b < 0.50 at% relative to M, and- D is present in the CAM in a content c :0.0 at% < c < 1.0 at% relative to M.

[0029] Optionally:- 85.0 at% < x < 95.0 at% relative to M,- 0.5 at% < y < 4.0 at% relative to M,- 4.4 at% < z < 8.0 at% relative to M,- 0.05 at% < a < 1.0 at% relative to M,- 0.05 at% < b < 1.0 at% relative to M, and- 0.0 at% < c < 1.0 at% relative to M.

[0030] Optionally:- 80.0 at% < x < 95.0 at% relative to M,- 0.5 at% < y < 9.0 at% relative to M,- 4.4 at% < z < 8.0 at% relative to M,- 0.05 at% < a < 1.0 at% relative to M,- 0.05 at% < b < 1.0 at% relative to M, and0.0 at% < c < 1.0 at% relative to M.

[0031] Optionally,- 80.0 at% < x < 100.0 at% relative to M,- 0.0 at% < y < 9.0 at% relative to M,- 0.0 at% < z < 8.0 at% relative to M,- 0.0 at% < a < 1.0 at% relative to M,- 0.0 at% < b < 1.0 at% relative to M, and0.0 at% < c < 1.0 at% relative to M.

[0032] D may include at least one element of: Ti, Al, Sr, Ba, Ca, B, Cr, Fe, Mg, Mo, Na, Nb, S, Si, V, W, Y, and Zn. D can be at least one element of Nb and Al, or is Nb and Al.

[0033] The cathode active material powder of the disclosure may have a D50 of at least 2.0 pm, or of at least 2.5 pm, or even of at least 3.0 pm.

[0034] The cathode active material powder according to the disclosure may have a D50 of at most 4.0 pm, or of no more than 3.5 pm.

[0035] The cathode active material powder according to the disclosure may have a span of more than 1.0 and less than 1.2, or of at least 1.0 and of at most 1.5, or of at least 1.1 and of at most 1.5.

[0036] The span of the CAM powder according to the disclosure may be in any of :- 1.1 < span < 1.4, or- 1.1 < span < 1.3, or- 1.1 < span < 1.2, or- span = 1.1.

[0037] The Li / (x+y+z+a+b+c) (at% / at%) ratio may be of < 1.00.

[0038] The Li / (x+y+z+a+b+c) (at% / at%) ratio may be of < 0.99.

[0039] The Li / (x+y+z+a+b+c) (at% / at%) ratio may be of > 0.95.

[0040] The Li / (x+y+z+a+b+c) (at% / at%) ratio can be of at least 0.95 and of at most 0.99, or of at least 0.95 and of at most 0.99.

[0041] The cathode active material powder or its sta ndalone particles may have M consisting (essentially) of:- Ni in a content x, with 80.0 at% < x < 100.0 at% or 85.0 at% < x < 100.0 at%, or 85.0 at% < x < 95.0 at%, or 90.0 at% < x < 95.0 at%, relative to M,- Mn in a content y, with 0.0 at% < y < 7.5 at%, or 0.0 at% < y < 5.0 at%, 0.0 at% < y < 2.5 at%, or 0.0 < y < 1.5 at%, or 0.0 < y < 1.0 at% relative to M,- Co in a content z, with 0.0 at% < z < 7.5 at%, or 0.0 at% < z < 5.0 at%, or 2.5 at% < z < 5.0 at% relative to M,- Ce in a content a, with 0.0 at% < a < 3.0 at%, or 0.0 at% < a < 1.0 at%, or 0.05 at% < a < 0.15 at%, or 0.10 at% < a < 0.15 at% relative to M,- Zr in a content b, with 0.0 at% < b < 1.0 at%, or 0.05 at% < b < 0.50 at%, or 0.10 at% < b < 0.15 at% relative to M, and- D in a content c, with 0.0 at% < c < 1.0 at%, or 0.0 at% < c < 0.75 at%, or 0.0 at% < c < 0.50 at%, or 0.25 at% < c < 0.50 at% relative to M, wherein D is an element different than Ni, Mn, Co, Ce and Zr, wherein x+y+z+a+b = 100.0 at%, x, y, z, a, b, and c being measured by ICP-OES or EDX.

[0042] Optionally, the cathode active material of the disclosure or the standalone particles may consist essentially of Li, O and M, wherein M consists essentially of Ni, Mn, Co, Ce, Zr, and D, wherein each of the elements included in M is present in the CAM in any of above-described contents.

[0043] The cathode active material according to the disclosure or the standalone particles may include more elements than Li, M and O. Additional elements can be for instance Na and S. Na and S maybe present in the pCAM as a results of its synthesis route: pCAM can be prepared following a co-precipitation process in a large-scale continuous stirred tank reactor (hereafter referred to as CSTR), with mixed nickel manganese cobalt sulfate(s), sodium hydroxide, and ammonia. After co-precipitation, the pCAM resulting from CSTR. synthesis includes S, respectively from raw NaOH and sulfate(s) of Ni, Mn and Co. The pCAM including S can be reacted with the Li source, the QI source, and optionally the Q2 source, as described above, thereby obtaining the CAM that includes S. Such a CAM therefore comprises not only Li, O, Ni, Mn, Zr, Ce, Al, Nb, and Co but also S. Indicatively, S can be present in the pCAM in a content of more than 0.0 at% and of at most 0.10 at%, relative to a sum of Ni, Mn and Co content in the pCAM. This element does not affect CAM claimed parameters.

[0044] The cathode active material according to the disclosure or the standalone particles may have a formula:LidN i(i-(y+z+a+b+c))M nyCOzCeaZrbDcO2, with 0.95 < d < 0.99, or 0.96 < d < 0.99 and wherein :- Ni in a content x, with 80.0 / 100 < x < 100.0 / 100 or 85.0 / 100 < x < 100.0 / 100, or 85.0 / 100 < x < 95.0 / 100, or 90.0 / 100 < x < 95.0 / 100, relative to M,- Mn in a content y, with 0.0 / 100 < y < 7.5 / 100, or 0.0 / 100 < y < 5.0 / 100, 0.0 / 100 < y < 2.5 / 100, or 0.0 < y < 1.5 / 100, or 0.0 < y < 1.0 / 100 relative to M,- Co in a content z, with 0.0 / 100 < z < 7.5 / 100, or 0.0 / 100 < z < 5.0 / 100, or 2.5 / 100 < z < 5.0 / 100 relative to M,- Ce in a content a, with 0.0 / 100 < a < 3.0 / 100, or 0.0 / 100 < a < 1.0 / 100, or 0.05 / 100 < a < 0.15 / 100, or 0.10 / 100 < a < 0.15 / 100 , or of 0.01 ± 0.009 relative to M,- Zr in a content b, with 0.0 / 100 < b < 1.0 / 100, or 0.05 / 100 < b < 0.50 / 100, or 0.10 / 100 < b < 0.15 / 100 relative to M, and- D in a content c, with 0.0 / 100 < c < 1.0 / 100, or 0.0 / 100 < c < 0.75 / 100, or 0.0 / 100 < c < 0.50 / 100, or 0.25 / 100 < c < 0.50 / 100 relative to M, wherein D is an element different than Ni, Mn, Co, Ce and Zr.

[0045] Ce content a can be 0.10 at% ± 0.09 at%.

[0046] Optionally, Ce content a can be any of the following range:- 0.0 at% < a < 2.0 at%,- 0.0 at% < a < 1.0 at%,- 0.0 at% < a < 0.90 at%,- 0.0 at% < a < 0.80 at%,- 0.0 at% < a < 0.70 at%,- 0.0 at% < a < 0.60 at%,- 0.0 at% < a < 0.50 at%,- 0.0 at% < a < 0.40 at%,- 0.0 at% < a < 0.30 at%,- 0.0 at% < a < 0.20 at%,- 0.0 at% < a < 0.15 at%, or 0.05 at% < a < 0.15 at%, and- 0.0 at% < a < 0.10 at%.

[0047] Zr content a can be any of the following range:- 0.0 at% < b < 0.90 at%,- 0.0 at% < b < 0.80 at%,- 0.0 at% < b < 0.70 at%,- 0.0 at% < b < 0.60 at%,- 0.0 at% < b < 0.50 at%,- 0.0 at% < b < 0.40 at%,- 0.0 at% < b < 0.30 at%,- 0.0 at% < b < 0.20 at%,- 0.0 at% < b < 0.15 at% or 0.10 at%, and- 0.05 at% < b < 0.15 at% or 0.05 at% < b < 0.15 at%.

[0048] Optionally, the CAM of the disclosure has a second formula LidNifioo at%- (y+z+a+b+c))MnyCozCeaZrbDcO2, with 95.0 at% < d < 99.0 at%, or 96 at% < d < 99 at% and with Ni+Co+Mn+Zr+Ce+D = M, and wherein :- Ni is present in a content x: 90.0 at% < x < 95.0 at% relative to M,- Mn is present in a content y: 0.5 at% < y < 2.0 at% relative to M,- Co in a content c: 4.4 at% < z < 6.0 at% relative to M,- Ce is present in the CAM in a content a : 0.05 at% < a < 0.50 at% relative to M,- Zr is present in the CAM in a content b : 0.05 at% < b < 0.50 at% relative to M, and- D is present in the CAM in a content c :0.0 at% < c < 1.0 at% relative to M, wherein x = 100 at%-(y+z+a+b+c)

[0049] Optionally:- 85.0 at% < x < 95.0 at% relative to M,- 0.5 at% < y < 4.0 at% relative to M,- 4.4 at% < z < 8.0 at% relative to M,- 0.05 at% < a < 1.0 at% relative to M,- 0.05 at% < b < 1.0 at% relative to M, and- 0.0 at% < c < 1.0 at% relative to M.

[0050] Optionally:- 80.0 at% < x < 95.0 at% relative to M,- 0.5 at% < y < 9.0 at% relative to M,- 4.4 at% < z < 8.0 at% relative to M,- 0.05 at% < a < 1.0 at% relative to M,- 0.05 at% < b < 1.0 at% relative to M, and- 0.0 at% < c < 1.0 at% relative to M.

[0051] Optionally- 80.0 at% < x < 100.0 at% relative to M,- 0.0 at% < y < 9.0 at% relative to M,- 0.0 at% < z < 8.0 at% relative to M,- 0.0 at% < a < 1.0 at% relative to M,- 0.0 at% < b < 1.0 at% relative to M, and- 0.0 at% < c < 1.0 at% relative to M.

[0052] 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.Process for manufacturing the CAM powder

[0053] The second object of the disclosure is a process for manufacturing the CAM powder according to the disclosure comprising:- a (first) step of mixing a precursor of the cathode active material with a Li source (for instance LiOH or U2CO3), a Zr source (e.g., ZrOz) and a Ce source (e.g., CeOz), thereby obtaining a first mixture powder,- a (second) step of heat treating the first mixture, optionally under oxidizing atmosphere, at a first temperature (Ti) of at least 700°C and at most 850°C, thereby obtaining a first fired material,- a (third) step of milling said first fired material, optionally together with an aqueous solution of Co, thereby obtaining a first intermediate material,- an optional (fourth) step of drying said first intermediate material, thereby obtaining a dried second intermediate material,- a (fifth) step of mixing the first intermediate material or the dried second intermediate material with a source of Co and optionally at least one source of D, thereby obtaining a second mixture,- a (sixth) step of heat treating the second mixture, optionally under oxidizing atmosphere, at a second temperature (T2) of at least 700°C and of at most 800°C, thereby obtaining a second fired material, and- a (seventh) step of grinding and sieving the second fired material, thereby obtaining the cathode active material powder.

[0054] During the second step, the first mixture may undergo:- an initial heat treatment at an initial temperature of at least 790°C and of at most 810°C, followed by- a subsequent heat treatment at a lower temperature than the initial temperature.

[0055] The fourth step may be performed by vacuum drying the first intermediate material at a drying temperature of at least 100°C and at most 200°C. The vacuum drying temperature can be of at least 150°C.

[0056] The source of D can be at least one of: Al, Sr, Ba, Ca, B, Cr, Fe, Mg, Mo, Na, Nb, S, Si, V, W, Y, and Zn.

[0057] In the fifth step, the at least one source of D can be: a Nb source, or and Al source, or a Co source, or any combination thereof. Optionally, the at least one source of D is:- a Nb source, and- a Co source, and- an Al source.

[0058] Nb, Co and Al sources can be an oxide of Nb, Co and Al. Nb source can be NbzOs. Co source can be CO3O4.

[0059] The third step may consist of a bead milling step of the first fired material.

[0060] During the third step, the first fired material can be milled together with an aqueous solution of cobalt sulphate (e.g., Co2(SO4)3 or COSO4).

[0061] The 3rdstep of milling the first fired material leads to the monolithic morphology of the CAM powder according to the disclosure, i.e., the milling step allows to achieve the cathode active material powder according to disclosure that includes (standalone) particles comprising at least one primary particle and at most twenty primary particles.

[0062] The grinding step can be performed on a third mixture powder of :- the second fired material, and- at least one source of Q, wherein Q is at least one of : Mg, Al, Nb, Zr, W, B, Ti, and Si, or at least one of : Al, W, and Si.

[0063] In the method of the disclosure, Al source can be an oxide like AI2O3. The source of W can be WO3. The source of Si can be SiO or SiO2.

[0064] Optionally, in the method of the disclosure: 720°C < Ti < 810°C, optionally during a period of at least 10 hours and at most 20 hours. The period ofthe heat treatment in the second step can be of at least 10 hours and at most 15 hours.

[0065] Optionally, in the method of the disclosure: 720°C < T2 < 740°C, or 730°C < T2 < 750°C, or even 730°C < T2 < 740°C, optionally during a period of at least 11 hours and at most 14 hours, or at least 12 hours and at most 13 hours.

[0066] During the second step, the first mixture may undergo:- an initial heat treatment at an initial temperature T3 of at least 790°C and of at most 810°C, or of at least 980°C and at most 810°C, followed by- a subsequent heat treatment at a lower temperature T4 than the initial temperature.

[0067] In the process according to the disclosure, Ti, T3, and T4 may relate to each other as follows:- T4< T3,- T3< 850°C or 810°C, and- 700°C < T4< 720°C.

[0068] Prior to the third step of milling, the first fired material may be air classified milled and sieved.

[0069] The third step of milling leads to the monolithic or the semi monolithic morphology of the CAM according to the disclosure.

[0070] The precursor of the CAM includes Ni, Mn and Co. The precursor of the CAM may be an oxide, hydroxide or oxyhydroxide of a compound comprising Ni, Mn, and Co. The content of Ni, Mn and Co in The CAM can be fine-tuned by adjusting contents of these elements in the pCAM. Ce, Zr and D relative contents are controlled during the first and optional fourth steps of the CAM manufacturing process, by adjusting relative weights of these elements in the first and second mixtures.Battery including the CAM powder and vehicle including the battery

[0071] 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 of the battery. The battery can be for instance a coin (or buttonjcell. Section C below provide a non-limitative embodiment of a coin cell. The battery can be a cylindrical, a prismatic or a pouch cell.

[0072] Various aspects according to the present disclosure are provided in the claims well as in the specification. The aspects and examples recited in the claimsand in the specification are mutually freely combinable unless otherwise explicitly stated.FIGURESFigure 1 : SEM images of a (secondary) particle according to EXI (a), 2 (b) and 3(c)EXPERIMENTAL ANALYSIS USED IN THE EXAMPLES AND THECOMPARATIVE EXAMPLE

[0073] The following analysis methods are used in the Examples and the Comparative Example.A) Inductively Coupled Plasma Optical Emission Spectrometry (ICP- OES) measurements

[0074] The amount of Li, Ni, Co, Mn, Al, Nb, Zr, and Ce 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.

[0075] 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 material.B) Particle sizeB-l) Particle size distribution analysis

[0076] 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 D99 / D50 or span = (D90-D10) / D50, where D10, D50, D90 and D99 are defined as the particle size at 10%, 50%, 90% and 99% of the cumulative volume% distributions, respectively, obtained from the Malvern Mastersizer 3000 with Hydro MV measurements. The <3pm (%) is defined as the particle size below 1pm expressed in %.B-l) Primary particle size analysis - DSEM

[0077] The average diameter of primary particles or single particles constituting the (secondary) particle of the CAM powder according to the disclosure can be defined as DSEM = ^‘=1 ppSsEM / n, wherein:" PPSSEMis a sizeofaprimary particle ( / ) of a (secondary) particle or a single (primary) particle of the CAM powder according to the disclosure, the pps being measured from a SEM image of the (secondary) particle an expressed in pm, and- n is a predetermined number of primary particles ( / ) which size is measured and n > 30.

[0078] The size pps of each of the n > / = 30 primary particles, and therefore the average size ( DSEM) can be measured according to the protocol provided below.

[0079] The average diameter of primary particles or single particles is calculated by using ImageJ software (ImageJ 1.52a, National Institutes of Health, USA) according to a protocol comprising:- a step 1) consisting of opening a file containing TT-SEM image (e.g. Figs la, lb, and lc) of a cathode active material including: a standalone (secondary) particle including several primary particles, or several single (primary particles), or at least one single (primary) particles and at least one standalone (secondary) particle particles obtained according to FE- SEM measurement method mentioned in section C) with 5000 timesmagnification wherein the image is taken to contain at least 30 primary particles,- a step 2) consisting of setting a scale according to the TT-SEM magnification, and- a step 3) consisting of drawing a line following primary particle's edge using 'polygon selections' tool for at least 30 primary particles that are not overlapped with other primary particles, thereby obtaining dawn primary particles perimeter based on a polygon approach from aforementioned 'polygon selections' tool. The primary particles at the edges of the TT-SEM image must be excluded if they are truncated,- a step 4) consisting of picking the 'Area' box tool from 'Set Measurements' menu, and measuring an area associated to each of the drawn primary particle perimeters.- a step 5) consisting of calculating a diameter d of each measured areas (associated to the primary particles) by assuming that each of the primary particles has a spherical shape, with d = 2 x ^ , thereby obtaining an average primary particles diameter (also referred to as average primary particle size) for at least 30 primary particles.C) X-ray diffraction (XRD) measurement

[0080] The X-ray diffraction pattern of the positive electrode material is collected with a Rigaku X-Ray Diffractometer (Ultima IV) using a Cu Ko radiation source (40kV, 40mA) emitting at a wavelength of 1.5418 A. The instrument configuration is set at: a 1° Soller slit (SS), a 10mm divergent height limiting slit (DHLS), a 1° divergence slit (DS) and a 0.3 mm reception slit (RS). The diameter of the goniometer is 158mm. For the XRD, diffraction patterns are obtained in the range of 5 - 85° (20) with a scan speed of 1° per min and a step-size of 0.02° per scan.D) Table Top SEM analysis

[0081] The morphology of positive electrode material powders is analyzed using a Table Top Scanning Electron Microscopy (TT-SEM) technique. The measurement is performed with a JEOL JSM 6000 scanning electron microscope equipment under a high vacuum environment of 9.6xl0‘5Pa at 25°C. The samples are prepared as follows:(1) CAM powder is placed and attached with carbon tape onto a mount(2) gold sputter coating is then applied on the CAM powder loaded on the mount.(3) The holder is inserted and fixed in the vacuum chamber of the measurement equipment wherein the vacuum atmosphere created.

[0082] The settings are adjusted according to the standard procedure (15kV) The images of samples are recorded with magnification (x5000).E) Coin cellE-l) Coin cell preparation

[0083] For the preparation of a positive electrode, a homogeneous slurry that contains a mixture of : i) a positive electrode active material powder, ii) a conductive material (Carbon black with dispersant, ANP), iii) a binder (KF#9700, Kureha) - with a formulation of 96.22: 1.98: 1.8 by weight, and iv) a solvent (NMP, Mitsubishi). The slurry is prepared by mixing the above-mentioned i) to iv) components in a high-speed homogenizer. The obtained 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 to obtain a pressed electrode that is subsequently is punched by 14pi puncher, thereby obtaining a coin cell electrode. Then, a coin cell electrode is dried in a vacuum oven in order to completely remove the remaining solvent present in the electrode film.

[0084] 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.

[0085] Herein, the coin cell electrode is a foil coated with the slurry (i.e. a mixture constituted of the CAM powder, the conductive material, the binder, and the solvent) whereas the coin cell is constituted of the coated foil as positive electrode, the separator, and the lithium foil.E-2) Coin cell testing Method

[0086] The testing method is a conventional "constant cut-off voltage" test. The conventional coin cell test in the present invention follows the schedule shownin Table 1. Each cell is cycled at 25°C using a Toscat-3100 computer-controlled galvanostatic cycling station (from Toyo).

[0087] The initial discharge capacity (DQ1) are measured in constant current mode (CC) at C rate of 0.1C in voltage range from 4.3V to 2.5V. The schedule uses a 1C current definition of 200 mA / g in the 4.3V to 2.5V / U metal range. The first cycle is evaluated at 0.1C.

[0088] The irreversible capacity QIRR. is expressed in % as follows:CQ1 - DQ1QIRR (%) = x 100CQ1

[0089] The difference between the average voltage at the initial charge (CV1) and the average voltage at the initial discharge (DV1) is an indicator of polarization of the positive electrode comprising the CAM powder under battery operation :CVl(m,V) DVl (mV) ^initial charge, average initial discharge, average

[0090] CV1 = WC1 / CQ1, wherein WC1 is a capacity in terms of power of the discharge during the first cycle (Wh). The capacity in terms of power is calculated from an area (integral) beneath the plotted graph of voltage (V) versus capacity (mAh / g) over the first discharge cycle of the battery.

[0091] DV1 is calculated by dividing the capacity in terms of power of the discharge during the first cycle (WD1) with DQ1, so that DV1 = WC1 / DQ1.

[0092] Low polarization means lower internal resistance and then limited electrochemical reactions between the positive electrode and the electrolyte. Therefore, the lowest the parameter CV1-DV1, the most performant the battery.F) Full cell TestingF-l) Full cell preparation

[0093] 2000 mAh pouch-type cells are prepared as follows: the positive electrode active material powder, Super-P (Super-P, Imerys Graphite & Carbon) as positive electrode conductive agents, and polyvinylidene fluoride (PVDF S5130, Solvay) as a positive electrode binder are added to N-methyl-2-pyrrolidone (NMP) as a dispersion medium so that the mass ratio of the positive electrode active material powder, the positive electrode conductive agents: super P: positive electrode binderis set at 95 / 3 / 2. Thereafter, the mixture is kneaded to prepare a positive electrode mixture slurry. The resulting positive electrode mixture slurry is then applied onto both sides of a positive electrode current collector, made of a 20 pm thick aluminium foil. The width of the applied area is 88.5 mm and the length is 425 mm. Typical loading weight of a positive electrode active material is about 14.8±1 mg / cm2. The electrode is then dried and calendared using a pressure of 4.5 MPa. In addition, an aluminium plate serving as a positive electrode current collector tab is arc-welded to an end portion of the positive electrode.

[0094] Commercially available negative electrodes are used. In short, a mixture of artificial graphite, carbon (Super P (Imerys)), carboxy-methyl-cellulose- sodium, and styrene-butadiene-rubber, in a mass ratio of 95.0 / 1 / 1.5 / 2.5, is applied on both sides of a copper foil. A nickel plate serving as a negative electrode current collector tab is arc-welded to an end portion of the negative electrode. Typical loading weight of a negative electrode active material is about 10 ± 1 mg / cm2.

[0095] Non-aqueous electrolyte is obtained by dissolving lithium hexafluorophosphate (LiPFe) salt at a concentration of 1.2 mol / L in a mixed solvent of ethylene carbonate (EC), ethyl methyl carbonate (EMC), and diethyl carbonated (DEC) in a volume ratio of 1 : 1 : 1. It contains 1.0 wt.% lithium difluorophosphate (UPO2F2), and 1.0 wt.% vinylene carbonate (VC) as additives.

[0096] A sheet of the positive electrode, a sheet of the negative electrode, and a sheet of the microporous polymer separator (13 pm) interposed between them are spirally wound using a winding core rod in order to obtain a spirally wound electrode assembly. The assembly and the electrolyte are then put in an aluminium laminated pouch in an air-dry room with dew point of -50°C, so that a flat pouchtype lithium secondary battery is prepared. The design capacity of the secondary battery is 2000 mAh when charged to 4.40 V. The full cell testing procedure uses a 1 C current definition of 2000 mA / g.F-2) Cycle life testA. Pre-charging and formation

[0097] The non-aqueous electrolyte solution is impregnated into the prepared dry battery for 8 hours at room temperature. The battery is pre-charged with the current of 0.25 C until 14% of its theoretical capacity and aged for a day at room temperature. The battery is then degassed using a pressure of -760 mmHg for 30seconds, and the aluminum pouch is sealed. During measurement, the pouch is assembled in a press jig provided with silicon pad.

[0098] The battery is charged with a current of 0.2 C in CC mode (constant current) up to 4.4 V and CV mode (constant voltage) until a cut-off current of C / 20 is reached. The battery is discharged with a current of 0.2 C in CC mode down to 2.7 V. Then, it is fully charged with a current of 0.50 C in CC mode up to 4.4 V and CV mode until a cut-off current of C / 20 is reached.

[0099] Afterwards, cell is discharged with a current of 0.50 C in CC mode down to 2.7 V. It is again charged with a current of 0.5 C in CC mode up to 4.4 V and CV mode until a cut-off current of C / 20 is reached. The final charging step is done in 25°C.B. Cycle life test

[0100] The lithium secondary full cell batteries are charged and discharged continuously under the following conditions at 25°C, to determine their chargedischarge cycle performance:- Charge is performed in CC mode under 1 C rate up to 4.4 V, then CV mode until C / 20 is reached,- The cell is then set to rest for 10 minutes,- Discharge is done in CC mode at 1 C rate down to 2.7 V,- The cell is then set to rest for 10 minutes,- The charge-discharge cycles proceed until 600 cycles. Every 100 cycles, the discharge is done at 0.1 C rate in CC mode down to 2.7 V.

[0101] The internal resistance or direct current resistance (DCR.) is measured at 1.5C for 10 s at the beginning of every 100 cycles repetition and the end of 600th cycles.

[0102] The cycle life is defined as the number of charge-discharge cycles when the capacity degrades to 80%.C. Bulging test

[0103] 650 mAh pouch-type batteries prepared by above preparation method are fully charged until 4.4V and inserted in an oven which is heated to 90°C, then stays for 4 hours. At 90°C, the charged positive electrode reacts with an electrolyte and creates gas. The evolved gas creates a bulging. The increase of thickness ((thickness after storage-thickness before storage) / thickness before storage)) is measured after 20 hours.EXAMPLESThe present disclosure is further illustrated in the following examples.Comparative Example 1 (CEX1)

[0104] A positive electrode active material CEX1 is obtained through following steps:1) Precursor preparation: a transition metal-based precursor having a formula: Nio.96Mno.oiCoo.o3(OH)2 was prepared by a coprecipitation process in a large- scale continuous stirred tank reactor (CSTR.) with mixed nickel-manganese- cobalt sulfates, sodium hydroxide, and ammonia followed by filtering, washing, drying, and post treating to obtain precursor.2) First mixing: the pCAM Nio.96Mno.oiCoo.o3(OH)2 prepared from the step 1) and LiOH are mixed homogeneously to prepare a first mixture.3) First heating and milling: The first mixture is heated at 805°C for lOh and step cooling to 720°C for 5h under oxygen atmosphere followed by ACM and sieving using 200mesh. The sintered material is bead milled (solid content of 65%) with 0.5mol% of Co from C0S04 (Co to metal (Ni, Mn, Co) atomic ratio of 0.03) to achieve the D50 value in Table 1 for in-situ coating and vacuum dried at 150°C.4) Second mixing and second firing: The dried obtained powder is dry mixed with 500ppm of Al from AI2O3 powder, 500ppm of Nb from Nb20s powder, and 1.5mol% of Co from CO3O4 powder. The mixed powder is fired at 730°C for 13h under oxygen atmosphere followed by grinding and sieving process together with AI2O3 powder using 270mesh.Example 1 (EXI)

[0105] A positive electrode active material EXI is prepared according to the same method as CEX1 except that the 0.1mol% of Zr from ZrO2 powder and 0.1mol% of Ce from CeC powder were homogeneously mixed with the precursor and LiOH in step 1).Example 2 (EX2)

[0106] A positive electrode active material EX2 is prepared according to the same method as CEX1 except that the 0.2mol% of Zr from ZrO2 powder and 0.13mol% of Ce from CeC powder were homogeneously mixed with the precursor and LiOH in step 1).Example 3 (EX3)

[0107] A positive electrode active material EX3 is prepared according to the same method as CEX1 except that the 0.3mol% of Zr from ZrO2 powder and 0.2 mol% of Ce from CeO2 powder were homogeneously mixed with the precursor and LiOH in step 1).Comparative Example 2 (CEX2)

[0108] A positive electrode active material CEX2 is obtained prepared according to the same method as CEX1 except that the 0.2mol% of Zr from ZrO2 powder were mixed with the precursor and LiOH in step 1).Comparative Example 3 (CEX3)

[0109] A positive electrode active material CEX3 is obtained prepared according to the same method as CEX1 except that the 0.2mol% of Ce from CeO2 powder were mixed with the precursor and LiOH in step 1).Comparative Example 4 (CEX4)

[0110] A positive electrode active material CEX4 is obtained prepared according to the same method as EXI except that the bead milling process of step 3) was not implemented.

[0111] All CAMS according to EXI, EXI', and EX2 and CEX1 to CEX3 results from a process including a step of bead milling the sintered material.Table la: CAM's physicochemical properties (1 / 2)Table lb: CAM's physicochemical properties (2 / 2)* DSEM is the average primary particle size value expressed in pm (measured over 30 primary particles) and measured according to Section B-l** According to CN'075's disclosure*** Cannot be measured according to protocol in Section B-l since no SEM image is available for this EX in CN'075&From SEM images of Figs. 1 to 4 of CN'705Table lc. CAM's propertiesTable 2a: CAM EC performances of Ex and CEXs.*Cycle life: 600cycle at 25°CTable 2b. CAM EC performances of EX and CEXs.

[0112] Results in Tables 2a and b demonstrate synergistical improvement of bulging for a monolithic CAM powder including Ce and Zr. This improvement includes:- lower CV1-DV1, i.e. low polarization when CAM powder of the disclosure is used in a battery, and therefore limited electrochemical reactions between the positive electrode including the CAM of the disclosure and the electrolyte;- thereby resulting in limited bulging of a battery using the CAM powders of the disclosure.

[0113] Such performances cannot be achieved with the CAM powder of CN'075, because they exhibit a smaller DSEM / D50 ratio values. Such small ratio values negatively affect cycle stability of a battery including such a CAM powder.

[0114] A small DSEM / D50 ratio value leads to increased side reactions with the electrolyte and the formation of unstable or excessive SEI layers, when the CAM is used in a battery. These reactions consume the electrolyte, leading to a degradation of battery electro-chemical performance (like cycling performance) over time, such as capacity fading.

[0115] Moreover, cycle life and DQ1 remain high and unaffected by the join addition of Ce and Zr.

[0116] 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 features or 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 suitable for Li-ion secondary batteries, comprising Li, M, and 0, wherein M includes :- Ni in a content x, with 80.0 at% < x < 100.0 at% or 85.0 at% < x < 100.0 at%, or 85.0 at% < x < 95.0 at%, or 90.0 at% < x < 95.0 at%, relative to M,- Mn in a content y, with 0.0 at% < y < 7.5 at%, or 0.0 at% < y < 5.0 at%, 0.0 at% < y < 2.5 at%, or 0.0 < y < 1.5 at%, or 0.0 < y < 1.0 at% relative to M,- Co in a content z, with 0.0 at% < z < 7.5 at%, or 0.0 at% < z < 5.0 at%, or 2.5 at% < z < 5.0 at% relative to M,- Ce in a content a, with 0.0 at% < a < 3.0 at%, or 0.0 at% < a < 1.0 at%, or 0.05 at% < a < 0.15 at%, or 0.10 at% < a < 0.15 at% relative to M,- Zr in a content b, with 0.0 at% < b < 1.0 at%, or 0.05 at% < b < 0.50 at%, or 0.10 at% < b < 0.15 at% relative to M, and- D in a content c, with 0.0 at% < c < 1.0 at%, or 0.0 at% < c < 0.75 at%, or 0.0 at% < c < 0.50 at%, or 0.25 at% < c < 0.50 at% relative to M, wherein D is an element different than Ni, Mn, Co, Ce and Zr, wherein x+y+z+a+b = 100.0 at%, x, y, z, a, b, and c being measured by ICP- OES, the cathode active material powder comprising particles comprising at least one primary particle and at most twenty primary particles, the cathode active material powder having a DSEM / D50 ratio of at least 0.

602. The cathode active material powder according to claim 1, wherein D includes at least one element of: Sr, Ba, Ca, Al, B, Cr, Fe, Mg, Mo, Na, Nb, S, Si, V, W, Y, and Zn.

3. The cathode active material powder according to claim 1 or 2, having a D50 of at least 2.5 pm.

4. The cathode active material powder according to claim 3, having a D50 of at most 4.0 pm.

5. The cathode active material powder according to any of the preceding claims, having a span of more than 1.0 and less than 1.2.

6. The cathode active material according to any of the preceding claims, having a Li / (x+y+z+a+b+c) (at% / at%) ratio of < 1.00.

7. The cathode active material according to any of the preceding claims, having a Li / (x+y+z+a+b+c) (at% / at%) ratio of < 0.99.

8. The cathode active material according to any of the preceding claims, having a Li / (x+y+z+a+b+c) (at% / at%) ratio of > 0.95.

9. The cathode active material according to any of the preceding claims, wherein D is at least one element of Nb and Al, or is Nb and Al.

10. A process for manufacturing the cathode active material powder according to any of the preceding claims, comprising:- a first step of mixing a precursor of the cathode active material with a Li source, a Zr source and a Ce source, thereby obtaining a first mixture powder,- a second step of heat treating the first mixture, optionally under oxidizing atmosphere, at a first temperature of at least 700°C and at most 850°C, thereby obtaining a first fired material,- a third step of milling said first fired material together with an aqueous solution of Co, thereby obtaining a first intermediate material,- a fourth step of drying said first intermediate material, thereby obtaining a dried second intermediate material,- a fifth step of mixing the dried second intermediate with a source of Co and optionally at least one source of D, thereby obtaining a second mixture,- a sixth step of heat treating the second mixture, optionally under oxidizing atmosphere, at a second temperature of at least 700°C and of at most 800°C, thereby obtaining a second fired material, and- a seventh step of grinding and sieving the second fired material, thereby obtaining the cathode active material powder.

11. The process according to claim 10, wherein during the second step, the first mixture undergoes:- an initial heat treatment at an initial temperature of at least 790°C and of at most 810°C, followed by- a subsequent heat treatment at a lower temperature than the initial temperature.

12. The process according to claim 10 and 11, wherein the fourth step is performed by vacuum drying the first intermediate material at a drying temperature of at least 100°C and at most 200°C.

13. A battery comprising the cathode active material according to any of the claims 1 to 9.

14. An electric vehicle comprising the battery of claim 13.

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