Method for manufacturing a cathode active material powder

Abstract

The present disclosure provides a method for manufacturing a cathode active material comprising Li, O, M', wherein M' includes : - Ni in a content x, wherein 60.0 at% ≤ x < 80.0 at%, relative to M', - Mn in a content y, wherein 20.0 at% ≤ y ≤ 30.0 at%, relative to M', - Co in a content z, wherein 5.0 at% ≤ z ≤ 8.0 at%, relative to M', - Al in a content a, wherein 0.4 at% < a ≤ 0.80 at%, relative to M', - Zr in a content b, wherein 0.0 at% ≤ b ≤ 0.50 at%, relative to M', - B in a content c, wherein 0.2 at% < c ≤ 0.50 at%, relative to M', and - W in a content d, wherein 0.05 < d ≤ 0.20 at%, relative to M', wherein x+y+z+a+b+c+d is 100.0 at% as determined by ICP-OES.

Description

METHOD FOR MANUFACTURING A CATHODE ACTIVE MATERIAL POWDER TECHNICAL FIELD

[0001] The present disclosure relates to i) a process for manufacturing a cathode active material or positive electrode active material (hereafter referred to as CAM) comprising Al, B and W elements, and to ii) the CAM obtained from the process.

[0002] In the present disclosure the terms “cathode active material” or “positive electrode active material” can be used interchangeably. Also, in the present disclosure the terms “CAM powder” or “CAM” can be used interchangeably. The CAM is made from a precursor (hereafter referred to as pCAM) thereof. 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. The precursor of the CAM can be an oxide, a hydroxide or an oxyhydroxide of M, with M comprising at least one transition metal element included in the CAM.

[0003] 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”.

[0004] 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 CAM from the process according to the present disclosure is suitable to be used in Li-ions secondary batteries. BACKGROUND

[0005] A process for manufacturing a CAM with Al, B and W is already known from EP4263437 (hereafter referred to as EP’437). This document discloses a process for manufacturing a CAM also comprising lithium (Li), nickel (Ni), manganese (Mn) and cobalt (Co). Such a CAM powder is also referred hereunder as NMC (NiMnCo) CAM powder. In particular, the present disclosure relates to a process for manufacturing a NMC CAM containing a high content of Ni, hereafter referred as hNMC, e.g. a hNMC CAM comprises a Ni / (Ni+Mn+Co) ratio of at least 60.0 at%, each of Co / (Ni+Mn+Co) and Mn / (Ni+Mn+Co) ratios being of 20 at% (e.g., NMC622). 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 several (or at most all) atoms in a claimed composition. at% can be measured by inductively coupled plasma - optical emission spectrometry (hereafter referred to as ICP-OES).

[0006] The process disclosed in EP’437 (for instance EX1) includes three heat treatment steps. More specifically, it comprises : - a first step of mixing an oxidized hydroxide [Oa(OH)(2-a), with a < 2] of Ni0.68Mn0.27Co0.05as pCAM with a LiOH as Li source so as to obtain a first mixture, - a second step of heat treating the first mixture at a first temperature of 925°C during 10 hours, so as to obtain a first fired material, - a third step of mixing the first fired material with LiOH, ZrO2, Co3O4and Al2O3so as to obtain a second mixture, - a fourth step of heat treating the second mixture at a second temperature of 775°C during 12 hours, so as to obtain a second fired material, - a fifth step wherein the second fired material is mixed with WO3and H3BO3, so as to obtain third mixture that is subsequently heat treated at 375°C during 7 hours, and - a final step of grinding an sieving in presence of a free flowing agent like Al2O3.

[0007] The CAM from the process of EP’437 has low initial charge and discharge capacities (hereafter respectively referred to as CQ1 and DQ1), and leads to high bulging when used in a LiB. Moreover, the process according to EP’437 has three heat treatment steps and bears therefore a relatively high operating expense (hereafter referred to as OPEX).

[0008] It is therefore an object of the present disclosure to provide a process which bears less OPEX and leads to a CAM with improved electrochemical (hereafter referred to as EC) properties. SUMMARY OF THE DISCLOSURE

[0009] This first object is achieved by providing a process according to claim 1.

[0010] The subject-matter of claim 1 refers to a process for manufacturing a cathode active material powder comprising Li, O, M’, wherein M’ includes Mn, Co, and Ni. Ni is present in M’ in a content (x) of at least 60.0 at% and of less than 80.0 at%, or of at least 60.0 at% and at most 70.0 at%, or even of at least 65.0 at% and at most 75.0 at%, relative to M’ and as measured by ICP-OES, said process comprising: - a first step of mixing a precursor of the cathode active material with a Li source, a first source of Al and optionally, a Zr source, to obtain a first mixture, - a second step of heat treating the first mixture powder, optionally under oxidizing atmosphere, at a first temperature of at least 800°C and at most 1000°C, thereby obtaining a first fired material, - a third step of milling the first fired material, thereby obtaining a first intermediate powder, - a fourth step of mixing the first intermediate powder with a second source of Al, a B source, and a W source, thereby obtaining a second mixture, - a fifth step of either: o mixing the second mixture powder with a third source of Al and with water, or o mixing the second mixture powder with an aqueous source of Al, thereby obtaining a third mixture, - a sixth step of heat treating the third mixture, optionally under oxidizing atmosphere, at a second temperature of at least 300°C and of at most 500°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.

[0011] Alternatively, the fourth and fifth steps may be a single step wherein first intermediate powder is mixed with the second source of Al, the B source, and the W source, and with either the third source of Al and with water or with the aqueous source of Al.

[0012] It is indeed observed that the cathode active material obtained from the process of the disclosure has high CQ1. Moreover, relatively high initial discharge capacity (hereafter referred as to DQ1), as well as Eff. and low bulging are achieved with the CAM manufactured according to the process of the disclosure, as supported by the results provided in Tables 1(a, b, & c) to 3.

[0013] The process according to disclosure allows to achieve a CAM having Al, B, and W with only two heat treatment steps, and is therefore less costly.

[0014] The process according to the disclosure includes the following aspects:

[0015] The process can have at most two steps of heat treating a mixture at a temperature of at least 300°C and at most 1000°C.

[0016] The Ni content x of the CAM can be: 65.0 at% ≤ x ≤ 75.0 at%, or 60.0 at% ≤ x ≤ 70.0 at%, or 60.0 at% ≤ x ≤ 75.0 at%, relative to M’.

[0017] The third step of milling may consist of jet milling the first fired material.

[0018] The first Al source can be replaced or added in combination with by at least any of a Si (like SiO2) or W source (like WO3).

[0019] The first mixture can have a (at% / at%) ratio of CLi / (∑i=ni=1 Ei ) of at least1.00 and of at most 1.10, or equal to 1.05 ± 0.05 as determined by ICP-OES, whereinCLi (expressed in at%) is a Li content in the first mixture and ∑i=ni=1 Ei is a sum ofindividual content Ei(expressed in at%) of each of the elements different than Li in the first mixture. Eiis at least one of Al, Ni, Co, and Mn, or at least one of Al, Ni, Co, Mn, and optionally Zr, Si and W. Therefore Eiis not Li and / or O.

[0020] The second mixture can have a (at% / at%) ratio of CLi2 / (∑i=ni=1 E′i ) of atleast 1.00 and of at most 1.10, or equal to 1.05 ± 0.05 as determined by ICP-OES,wherein CLi2 (expressed in at%) is a Li content in the second mixture and ∑i=ni=1 E′i is asum of individual content E’i(expressed in at%) of each of the elements different than Li in the first mixture. E’ican be at least one of Al, B, W, Ni, Co, and Mn or at least one of Zr, Al, B, W, Ni, Co, and Mn, or even at least one of Si, Zr, Al, B, W, Ni, Co, and Mn. Therefore E’iis not Li and / or O.

[0021] The first and / or the second mixture may be a powder. The third mixture obtained from the seventh step can be a slurry comprising a solid phase including the second mixture powder and an aqueous liquid phase.

[0022] Optionally, in the seventh step, a fourth source of Al is added to the second fired material during grinding. The fourth source of Al can be replaced or added in combination with by at least any of a Si (like SiO2) or W source (like WO3).

[0023] The second step of heat treating the first mixture powder may be performed at a first temperature of at least 900°C and at most 950°C.

[0024] The second step of heat treating the first mixture powder is performed during a first time period of at least 9 hours and at most 10 hours.

[0025] The sixth step of heat treating the third mixture can be a step of heating and drying the slurry so as to obtain the second fired material.

[0026] The sixth step of heat treating the third mixture may be performed at a second temperature of at least 350°C and at most 390°C.

[0027] The sixth step of heat treating the third mixture may be performed during a second time period of at least 6 hours and at most 8 hours.

[0028] The Li source can be at least one of LiOH, LiF, LiNO3, Li2SO4, LiPF6, LiI, Li2S, LiBr, and LiCl.

[0029] The Li source can be LiOH or Li2CO3.

[0030] The Zr source can be at least one of: ZrO2, ZrH2, ZrF4, ZrN, Zr(NO3)4, ZrCl4, ZrC, and Zr(OH)4.

[0031] The B source can be at least one of : H3BO3, BN, B4C, and B(OH)3.

[0032] The W source can be at least one of : WO3, WO2, W2N, and WCl6.

[0033] Any of the first, second and fourth sources of Al can be at least one of: Al2O3, AlOOH, AlN, Al(NO3)3, AlCl3, and AlF3.

[0034] The Zr source can be at least one of ZrO2, ZrH2, ZrF4, ZrN, Zr(NO3)4, ZrCl4, ZrC, and Zr(OH)4. The B source can be H3BO3, BN, B4C, and B(OH)3. The W source can be at least one of WO3, WO2, W2N, and WCl6.

[0035] The first, second and fourth sources of Al can be at least one of Al2O3, , Al(NO3)3, AlCl3, and AlF3. The third source of Al can be Al2(SO4)3. The aqueous source of Al can be an aqueous solution of Al2(SO4)3. Optionally, the aqueous solution of Al2(SO4)3comprises SO4at a concentration of at least 0.020 mol% and at most 0.030 mol%, or of at least 0.025 mol% and at most 0.030 mol%. The aqueous solution of Al2(SO4)3may equivalently comprise Al at a concentration of at least 0.030 mol% or at% and at most 0.060 mol% or at%, or of at least 0.0350 mol% or at% and at most 0.045 mol% or at%. The term “mol%” means a percental of moles or mol of an element or compound in a composition, e.g. Al or SO4.

[0036] The third step of milling can be performed with an air jet miller with air injected at a pressure of 0.25 MPa (megapascal) with a vortex speed calibrated at3000 rpm (revolution per minute) at a room temperature. Jet milling conditions can be adjusted to achieve D50 values according to disclosure.

[0037] The process of the disclosure may consist of: - a first step of mixing a precursor of the cathode active material with a Li source, a first source of Al and optionally, a Zr source, to obtain a first mixture, - a second step of heat treating the first mixture powder, optionally under oxidizing atmosphere, at a first temperature of at least 800°C and at most 1000°C, thereby obtaining a first fired material, - a third step of milling the first fired material, thereby obtaining a first intermediate powder, - a fourth step of mixing the first intermediate powder with a second source of Al, a B source, and a W source, thereby obtaining a second mixture, - a fifth step of either: o mixing the second mixture powder with a third source of Al and with water, or o mixing the second mixture powder with an aqueous source of Al, thereby obtaining a third mixture, - a sixth step of heat treating the third mixture, optionally under oxidizing atmosphere, at a second temperature of at least 300°C and of at most 500°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.

[0038] M’ of the CAM obtained from the process according to the disclosure may comprise: - Ni in a content x, wherein 60.0 at% ≤ x < 80.0 at%, relative to M’, - Mn in a content y, wherein 20.0 at% ≤ y ≤ 30.0 at%, relative to M’, - Co in a content z, wherein 5.0 at% ≤ z ≤ 8.0 at%, relative to M’, - Al in a content a, wherein 0.40 at% < a ≤ 0.80 at%, relative to M’, - Zr in a content b, wherein 0.0 at% ≤ b ≤ 0.50 at%, relative to M’, - B in a content c, wherein 0.2 at% < c ≤ 0.50 at%, relative to M’, and - W in a content d, wherein 0.05 < d ≤ 0.20 at%, relative to M’, wherein x+y+z+a+b+c+d is 100.0 at% as determined by ICP-OES.

[0039] The cathode active material obtained from the process of the disclosure may have a Li / (x+y+z+a+b+c+d) (at% / at%) ratio of ≥ 1.00, or ≥ 1.01, or ≤1.10, or ≤ 1.05 as determined by ICP-OES. The Li / (x+y+z+a+b) (at% / at%) ratio can beof at least 1.00 and of at most 1.10, or of at least 1.01 and of at most 1.05, or of at least 1.01 and of at most 1.03, or of 1.03 ± 0.03 as determined by ICP-OES.

[0040] The CAM according to the disclosure may consist essentially of Li, O and M’ wherein M’ may consist essentially of: - Ni in a content x, wherein 60.0 at% ≤ x < 80.0 at%, relative to M’, - Mn in a content y, wherein 20.0 at% ≤ y ≤ 30.0 at%, relative to M’, - Co in a content z, wherein 5.0 at% ≤ z ≤ 8.0 at%, relative to M’, - Al in a content a, wherein 0.4 at% < a ≤ 0.80 at%, relative to M’, - Zr in a content b, wherein 0.0 at% ≤ b ≤ 0.50 at%, relative to M’, - B in a content c, wherein 0.2 at% < c ≤ 0.50 at%, relative to M’, and - W in a content d, wherein 0.05 < d ≤ 0.20 at%, relative to M’, wherein x+y+z+a+b+c+d is 100.0 at% as determined by ICP-OES.

[0041] Al, Zr, B, W, and Si can be encompassed in a group of elements Q.

[0042] In the process of the disclosure, 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.

[0043] 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 elements can be added to the mixture including the pCAM, the Li source and optionally the at least one Q source.

[0044] The cathode active material according to the disclosure 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 sulfates, 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, as described above, thereby obtaining the CAM that includes S. Such a CAM therefore comprises not only Li, O, Ni, Mn, Al, Zr, B and W, 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.

[0045] The cathode active material obtained from the process of the disclosure may have a layered structure. For instance, a layered structure of the α-NaFeO2type, or a layered structure of the α-NaFeO2type having a R-3m or R3m space group.

[0046] The cathode active material obtained from the process of the disclosure may be a monolithic powder. In the present disclosure the terms “monolithic powder” or “powder having a monolithic morphology” are equivalent. The terms monolithic powder refer to a powder including single or secondary particles, each of the secondary particles consisting of no more than twenty primary particles. The number of primary particles constituting the secondary particles is determined based upon a scanning electron microscopy (hereafter referred as to SEM) image, for instance, in a field of view of at least 45 μm x at least 60 μm (i.e. of at least 2700 μm²), preferably of at least 30 μm x 100 μm (i.e. of at least 3000 μm²). The secondary particles in the image should be well distributed therefore avoiding overlap between secondary particles. This can be achieved by pouring a small amount of powder sample to the adhesive attached on the SEM sample holder and blowing air to remove the excess powder. In the context of the present invention primary particles are distinguished from each other in a SEM image by observing grain boundaries between the primary particles. A grain boundary is defined as the interface between two primary particles, for instance wherein the atomic planes of the two primary particles are aligned to different orientations and meet as a crystalline discontinuity.

[0047] Single particles are grain free and each of them consists of solely one standalone particle.

[0048] The jet milling step of the process of the disclosure confers the monolithic morphology to the CAM powder of the disclosure.

[0049] Various aspects according to the present disclosure are provided in the claims 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. DETAILED DESCRIPTION OF THE DISCLOSURE EXPERIMENTAL ANALYSIS USED IN THE EXAMPLES AND THE COMPARATIVE EXAMPLES

[0050] The following analysis methods are used in the Examples and the Comparative Examples. A) ICP-OES measurement

[0051] The amount of Li, Ni, Co, Mn, Al, W, B, and Zr 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 HCl 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. Finally, 50mL of this solution is used for ICP-OES measurement.

[0052] 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 E1(Eat1) in a material can be converted from a given wt% of said first element E1(Ewt1) in said material by applying the following formula, ^^^^(^^^^^^^^^^^^1 / ^^^^^^^^^^^^1)^^^^^^^^1=∑^^^^^^^^=1 (^^^^^^^^^^^^^^^^ / ^^^^^^^^^^^^^^^^) × 100%,wherein Eaw1is a standard atomic weight (or molecular weight) of the first element E1, Ewtiis wt% of an ithelement Ei, Eawiis 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. In the framework of the present disclosure the term wt% means weight %. ppm stands for parts per million and is also used to express the concentration of an element in a material or mixture measured by ICP-OES. Ppm = weight (%) x 10000 or weight (%) = ppm / 10000, so that, for instance: 10000 ppm = 1 wt% and 5000 ppm = 0.5 wt%. B) Particle size distribution (PSD)

[0053] 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 is represented by D50 that is defined as the particle size at 50% of the cumulative volume% distributions, respectively, obtained from the Malvern Mastersizer 3000 with Hydro MV measurements.C) Brunauer-Emmett-Teller (BET) measurement

[0054] The specific surface area is measured with the Brunauer-Emmett-Teller (BET) method using a Micromeritics Tristar 3000. 2g of CAM powder sample is first dried in an oven at 120°C for 2h, followed by N2purging. Then the oven is degassed in vacuum at 120ºC for 1 hour prior to the measurement, in order to remove adsorbed species. D) X-ray diffraction (XRD) measurement

[0055] The X-ray diffraction pattern of the positive electrode material is collected with a Rigaku X-Ray Diffractometer (Ultima IV) using a Cu Kα radiation source (40kV, 40mA) emitting at a wavelength of 1.5418 Å. 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° (2θ) with a scan speed of 1° per min and a step-size of 0.02° per scan. E) pH titration-soluble base content measurements

[0056] The base content is a material surface property that can be quantitatively measured by the analysis of reaction products between the surface and water. If powder is immersed into water a surface reaction occurs. During the reaction the pH of the water increases (as basic compounds dissolve) and the base is quantified by a pH titration. The result of the titration is the “soluble base content” (SBC). The content of soluble base can be measured as follows: 100 ml of de-ionized (DI) water is added to 4g of cathode active material powder followed by stirring for 10 minutes. The aqueous solution is then removed by using Buchner filtration with suction, thereby achieving > 90g of clear filtered solution which contains the soluble base.

[0057] The content of soluble base is titrated by logging the pH profile during addition of 0.1 M HCl at a rate of 0.5 ml / min until the pH reaches 3.0 under stirring. A reference voltage profile is obtained by titrating suitable mixtures of LiOH and Li2CO3dissolved in low concentration in DI water. In almost all cases two distinct plateaus are observed. The upper plateau with endpoint γ1 (in mL) in a range of pH values between 8 and 9 corresponds to OH- / H2O couple, followed by CO32- / HCO3- couple, the lower plateau with endpoint γ2 (in mL) included in a range of pH values between 4 and 6 is associated to HCO3- / H2CO3couple. The inflection points betweenthe first and second plateau γ1 as well as the inflection point after the second plateau γ2 are obtained from the corresponding minima of the derivative dpH / dVol of the pH profile. The second inflection point generally is near to a pH value of 4.7.

[0058] Results are then expressed in LiOH and Li2CO3weight percent as follows: ^^^^^^^^2^^^^^^^^73.8909 3^^^^^^^^% =1000× (^^^^1 − ^^^^2);^^^^^^^^^^^^^^^^ ^^^^^^^^% =23.9483 1000× (2 × ^^^^1 − ^^^^2);F) Carbon analysis

[0059] The contents of carbon of the cathode materials are measured by Horiba EMIA-20E Carbon / Sulfur analyzer. 1 g of NMC sample is placed in a ceramic crucible in a high frequency induction furnace. 2.1g of Tungsten and 0.9g of Tin as accelerators are added into the crucible. The sample is heated at a programmable temperature. Gases produced during the combustion are then analyzed by four Infrared detectors. The analysis of low and high CO2and CO determines carbon concentration. G) Coin cell test G-1) Coin cell preparation

[0060] 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 90:5:5 by weight - in a solvent (NMP, Mitsubishi) is prepared by a high-speed homogenizer. The homogenized slurry is spread on one side of an aluminum foil using a doctor blade coater with a 230 µm gap. The slurry coated foil is dried in an oven at 120°C and then pressed using a calendaring tool with 40 μm gap.

[0061] 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. 1 M 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. G-2) Testing method

[0062] The testing method is a conventional “constant cut-off voltage” test. The conventional coin cell test in the present invention follows the schedule shown in Table 1. Each cell is cycled at 25°C using a Toscat-3100 computer-controlledgalvanostatic cycling station (from Toyo, http: / / www.toyosystem.com / image / menu3 / toscat / TOSCAT-3100.pdf).

[0063] 1C current definition is 160 mAh / g. The initial charge capacity (CQ1) and discharge capacity (DQ1) are measured in constant current mode (CC) at C rate of 0.1C in the 4.3 V to 3.0 V / Li metal window range.

[0064] The irreversible capacity IRRQ is expressed in % as follows: ^^^^^^^^^^^^^^^^ (%) = ^^^^^^^^1 − ^^^^^^^^1^^^^ 100 ^^^^^^^^1

[0065] The efficiency is represented by the following equation:H) Full cell testing H-1) Full cell preparation

[0066] 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 binder is 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 µm thick aluminum 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 aluminum plate serving as a positive electrode current collector tab is arc-welded to an end portion of the positive electrode.

[0067] 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.

[0068] Non-aqueous electrolyte is obtained by dissolving lithium hexafluorophosphate (LiPF6) salt at a concentration of 1.2 mol / L in a mixed solventof 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 (LiPO2F2), and 1.0 wt.% vinylene carbonate (VC) as additives.

[0069] A sheet of the positive electrode, a sheet of the negative electrode, and a sheet of the microporous polymer separator (13 µm) 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 aluminum laminated pouch in an air-dry room with dew point of -50°C, so that a flat pouch-type lithium secondary battery is prepared. The design capacity of the secondary battery is 2000 mAh when charged at 4.25V for a first set of data and at 4.35 V for a second set of data. The full cell testing procedure uses a 1 C current definition of 2000 mA / g. H-2) Cycle life test A. Pre-charging and formation

[0070] 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 30 seconds, and the aluminum pouch is sealed. During measurement, the pouch is assembled in a press jig provided with silicon pad.

[0071] The battery is charged with a current of 0.2 C in CC mode (constant current) up to 4.25V for the first data set and 4.35 V for the second data set, respectively 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 4.25 V and 4.35 V and CV mode until a cut-off current of C / 20 is reached.

[0072] 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 4.25 V and 4.35 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

[0073] The lithium secondary full cell batteries are charged and discharged continuously under the following conditions at 45°C, to determine their charge- discharge cycle performance:- Charge is performed in CC mode under 1 C rate up to 4.25V and to 4.35 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.

[0074] The cycle life is defined as the number of charge-discharge cycles when the capacity degrades to 80%.

[0075] The efficiency is represented by the following equation:H-3) Bulging test

[0076] 2000mAh pouch-type batteries prepared by above preparation method are fully charged until 4.25V 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. EXAMPLES

[0077] The present disclosure is further illustrated in the following examples and comparative examples.

[0078] Tables 1(a&b) and 2 provide a summary of the EC performances of the EX1 and CEXs whereas in Table 3, physicochemical properties of the CAM’s according to the EX1, CEXs, and prior art are provided. Comparative Example 1 (CEX1)

[0079] A positive electrode active material CEX1 is obtained through following steps: 1) First Mixing : the pCAM Ni0.68Mn0.27Co0.05(OH)2and LiOH (Li / Me=1.02) are mixed homogeneously to obtain a first mixture. 2) First heating and milling: the first mixture obtained from step 1) is heated at 925°C under oxygen atmosphere to obtain a first heated material.The sintered material is then milled by using jet milling under 0.25MPa for 3000rpm. 3) Second mixing: the jet milled material from step 2) is dry mixed with 2.0mol% of Co (Co to metal (Ni, Mn, Co) atomic ratio of 0.02) from Co3O4powder, 500 ppm of Al (Al to metal (Ni, Mn, Co) atomic ratio of 0.0017) from Al2O3powder , and 0.25 mol% of Zr (Zr to metal (Ni, Mn, Co) atomic ratio of 0.0025) from ZrO2powder to obtain a second mixture. 4) Second heating: the second mixture obtained from step 3) is heated at 775°C under oxygen atmosphere followed by crushing and sieving process together with alumina (Al2O3) powder, thereby obtaining a second heated powder. 5) Third mixing and heating: the second heated powder obtained from the step 4) is mixed with 500ppm B (B to metal (Ni, Mn, Co) atomic ratio of 0.0041) from H3BO3powder and 2000ppm of W (W to metal (Ni, Mn, Co) atomic ratio of 0.0010) from WO3powder. The mixture was then sintered at 375°C followed by crushing and then sieving process together with alumina (Al2O3) powder to obtain a positive electrode active material powder CEX1. Example 1 (EX1)

[0080] A positive electrode active material EX1 is obtained through following steps: 1) First Mixing: the pCAM with a formula Ni0.67Mn0.26Co0.07(OH)2, LiOH (Li / Me=1.02), 0.25 mol% of Zr (Zr to metal (Ni, Mn, Co) atomic ratio of 0.0025) from ZrO2powder and 500 ppm Al (Al to metal (Ni, Mn, Co) atomic ratio of 0.0017) from Al2O3powder are mixed homogeneously to obtain a first mixture. 2) First heating and milling: the first mixture obtained from step 1) is heated at 920°C under oxygen atmosphere to obtain a first heated material. The sintered material is then milled by using jet milling, thereby obtaining a jet milled material. 3) Second mixing: the jet milled material from step 2) is dry mixed with 250ppm Al (Al to metal (Ni, Mn, Co) atomic ratio of 0.008) from Al2O3powder, 500ppm of B (B to metal (Ni, Mn, Co) atomic ratio of 0.0042) from H3BO3powder and 2000ppm of W (W to metal (Ni, Mn, Co) atomic ratio of 0.0002) from WO3 powder and the 250ppm of Al (Al to metal (Ni, Mn, Co) atomic ratioof 0.0008) from aqueous solution Al2(SO4)3was added to the dry mixed material by using an Eirich mixer, thereby obtaining a second mixture. 4) 2ndsintering: the second mixture obtained from the step 3) was sintered at 375°C under air atmosphere followed by crushing and then sieving process together with alumina (Al2O3) powder to obtain a positive electrode active material powder EX1. Comparative Example 2 (CEX2)

[0081] A positive electrode active material CEX2 is obtained through following steps: 1) First Mixing: the pCAM having the formula Ni0.67Mn0.26Co0.07(OH)2, LiOH (Li / Me=1.02), 0.25mol% of Zr (Zr to metal (Ni, Mn, Co) atomic ratio of 0.0025) from ZrO2powder and 500ppm of Al (Al to metal (Ni, Mn, Co) atomic ratio of 0.0017) from Al2O3powder are mixed homogeneously to obtain a first mixture. 2) First heating and milling: the first mixture obtained from step 1) is heated at 920°C under oxygen atmosphere to obtain a first heated material. The sintered material is then milled by using jet mill process. 3) Second mixing: the jet milled materials from step 2) is dry mixed with 500ppm of Al (Al to metal (Ni, Mn, Co) atomic ratio of 0.0017) from Al2O3powder, 500ppm of B (B to metal (Ni, Mn, Co) atomic ratio of 0.0042) from H3BO3powder and 2000ppm of W (W to metal (Ni, Mn, Co) atomic ratio of 0.0010) from WO3powder. 4) 2ndsintering: the mixture obtained from the step 3) was sintered at 375°C under air atmosphere followed by crushing and then sieving process together with alumina (Al2O3) powder to obtain a positive electrode active material powder CEX2.

[0082] In any of the above-mentioned EX1 and CEXs, the pCAM with the formula Ni0.67Mn0.26Co0.07(OH)2is prepared by a co-precipitation 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.

[0083] Table 1c provides ppm and at% contents of additives for each of the EX1 and CEXs.Table 1a: CAM’s EC performances of the EX1 and CEXs *cycle test at 4.35V CAM composition (at%) Full Cell* EX IDs M’ CQ1 DQ1 Eff.** Li / M’ Ni Mn Co Zr Al B W mAh / g mAh / g % EX1 1.01 66.46 25.31 6.91 0.22 0.50 0.446 0.104 219.9 190.2 86.5 CEX1 1.01 66.30 25.61 6.80 0.22 0.50 0.453 0.103 217.0 188.9 87.0 CEX2 1.02 67.01 25.27 6.39 0.22 0.56 0.459 0.106 218.3 188.6 86.4 **(DQ1 / CQ1) x 100 Table 1b: CAM’s EC performances of the EX1 and CEX Full cell* EX IDs Bulging ** % EP’437 25.9 EX1 EX1 14.3 CEX1 15.8 CEX2 69.2 *cycle test in 4.25V **after 20 hours**t tnse. .oapmt.Oa.anNnert*.a21.tn %t .4. .a.ua n 0 0 ng onimxa §im.a00Mp . 00.a50 .drp n 2 n3 se) vit.3) ia 3.d.O B OadnB H3W.W( na (**t tnseS S S o pmtEaYEYEYert*8 7 2 5 7 0 7 2t%0nt .0.4.1.2.1 0.1 4ua 0 0 0 0 0.02.0.0os gX nm i A§Exm0 00 000Ci5 0000 0 0051000 mpp2 2 50252535 5dnd 1an21s) ) )3) ) ) )Xev3 4 3)3)2 3 4)3 3E irtildAlO2 lO O AS(B B3WOrOWZr lAO2 oO3 lO2O B B ZlCoAl 3of d Aa( l 2H( ( (A(C(A(H(o At (ere**htt t nds eS O Seo mtEY NEtpaYale er rttnu*o5 7%2 15271mt t . . . .an a 0 0 0 0d un oag §ms nimexam08000 .8 ppvip 4iti mp 2 5 a. 4200d t ns5d1asf ev ) ) ) ) i2 l 3 2 3orOOrOlOttsii ldZrA2dZlZrA2Zla (A( (A(:c1 1 2el D1IX X Xb E E EaC CTlatotno p udesa b§;)3O l2A(ecru osl A f o m p p 0 0 5gnisude0t1c.u0dn ocs0a00 w 2tn e mt)a3eOrWtW(tso P * *;)n M + o C +iN(.svdetaluclacere wtn ecM r A e pCfci otm ohtgiae*wTable 2a: CAM’s EC performances of the EX1, CEX1 and EP’437 EX1 CAM EC composition Coin cell EX IDs (at%) M’ CQ1 DQ1 IRRQ* Efficiency Ni mAh / g mAh / g % (%) EX1 64.5 201.9 173.2 14.2 85.79 EP’437 86.13 66.5 201.2 173.3 13.9 EX1 CEX1 66.3 202.6 173.1 14.7 85.44 *IRRQ(%) = 100% x (CQ1-DQ1) / CQ1 Table 3: CAM’s physicochemical properties CAM PSD EX IDs Carbon SBC BET D50 ppm μmol / g m2 / g μm EX1 204 151 0.799 3.90 CEX1 199 171 0.625 4.29 CEX2 187 113 0.797 4.09

[0084] The Al, Zr, B, and Zr were converted to at% from ppm based on a molar (or atomic) mass of each of the elements of a reference composition of the pCAM, intermediate, and CAM (pCAM relates to the 1stmixing step whereas intermediate and CAM relates to the 2ndand 3rdmixing steps).

[0085] For instance, in EX1, 500ppm of Al was added to a pCAM reference composition of Ni₀.₆₇Mn₀.₂₆Co₀.₀₇(OH)₂ (molar mass = 91.748 g / mol). Based on the molar mass related to the pCAM composition and the atomic mass of Al (atomic mass=26.98 g / mol), the corresponding atomic percent was calculated at approximately 0.17at%. The atomic percent of Zr, B, and W was calculated using the same method as described above for Al. The reference composition varies depending on the elements added and specific EX and CEXs used.

[0086] The CAM powder according to the disclosure allows reduced bulging and increased safety, due to limited C content, SBC and BET (cf. Tables 1(a & b) and 3).

[0087] Compared to prior art, the CAM powder obtained by the process of the disclosure has improved CQ1, DQ1 and IRRQ (Table 2). This comparison is made at equivalent Ni content (i.e. Ni content of at least 64 at% and no more than 67 at%). As show in Table 3, the process according to the disclosure allows production of R- 3m CAM powders with: 1) limited SBCs and C contents, and 3) controlled BET. Limited SBC is desired to minimize presence of Li salt impurities (LiOH and / or Li2CO3) at a surface of CAM particles.

[0088] A high SBC, for instance a content of more than 160 µmol / g, is related to several highly undesired phenomena. First, the large scale preparation of electrodes by coating requires that coating slurries (containing amongst others the cathode active material and a binder in a solvent) are stable. We refer to this property as “slurry stability”. A good slurry stability means that the viscosity does not change dramatically during coating. In a worst case scenario “gelation” of the slurry can occur, making the coating impossible. A good slurry stability also means that the quality of the dispersion of cathode powder, conductive additives, etc. in the binder solution does not change. In a worst case scenario flocculation can occur, causing carbon-carbon and / or cathode-cathode agglomeration. It was observed that high SBC tends to cause a poor slurry stability.

[0089] Furthermore, if the CAM contains high SBC then the high temperature performance of batteries is influenced. During high temperature exposure of charged batteries gas evolves. This gas evolution is highly undesirable because it causes bulging of the cells.

[0090] In the present disclosure, it is demonstrated that the claimed process allows to manufacture CAM powders with limited SBC, compared to a process comprising three heating steps (CEX1). BET of EX1 remains close to CEX1 one. It is key: as the surface area of the positive electrode active material powder increases, the area of a region in which a side reaction may occur also increases. This side reaction may cause a phase transformation in which the crystal structure of the lithium composite oxide constituting the positive electrode active material powder is changed. Such a phase transformation of the crystal structure in the surface of the positive electrode active material powder is one of the causes of reducing the electrochemical characteristics, such as the lifespan characteristics like IRRQ, of the lithium secondary battery. A BET from 0.6 to 0.8 remains acceptable.

[0091] C content in a CAM should be minimal, since this element is a non- electrochemically active impurity. The process of the disclosures allows to manufacture a CAM with limited C content. C content is also linked to Li2CO3part of SBC. Therefore, the higher the SBC, the higher the C content is measured in the CAM.)S3O g Whn: 7it e+C° :a r 3e- -uO5 nhtB733oiM t A- -dxiH: arC r 3 M + 2T 3u _tD nI(**) L) 34 O**Ss( *)3l 2)SOA +3O2 l 2rA + O Z32gni : lht eAC8+4hOhC8C8+° : :e O3 ° : :e W° :a reu35O7no MruoC57n2 o_r+35 ndh txtuO7 oM niW3 i+:tAtCxi+37 i:tntxiB33 i:tA C 32ar O 2ar IH2ar2 M OTu Ml 2 Tu M +Tu B D A D H3H D + 1 Oi+_ LHtn+ Oi I 1_L (t+nI1(_tnI(ygr tnis1 _s1 _s1 _ Dejlli eYtneYt eYtInInsmIet*S*u) )Sor 303sO H Oi l2_)Ol2seAhtih+0nL h0Ah+0tg:2C 1I(+C1:2C 1nni e Or °: M° :0e O°:yt rZ02n et A5 nr r0 n0sas eut+9oi aiCp 29oi _tuZ2X h x nt+9o_itnE tsiH:tO1a d::t IxiH:tr ee1arO1aIC1 MiL Tumr Tu MiL T rdrutu +nD D +aMeAtxniD M A1CIM CXp pE( (:4l1 1 2ebX X XaE ECECT)S3O g Whn: 7it e+C° :a r 3O5 ne utB7M 3oidhxriH3:tA a C M +2 r32Tu _tD nI(*)S O2rZ +4O go 3 h2ni :teCC° 1a r+ eu35:2 O7no_tdh txni l 27 iA:tanI2 M + HT 2 ru OiD L + 1_tnI(ygr tniDejl s1 li e_YtmnIH OiL hg+0nitM CA° 1e5: sn 0aaeCp 29oi _tt hne p-th:: aI sss er 1 rah u1uTtup oxD- eidiulqMoas ssnnaae7e3m41m ’X””LPES“E”***Tables 1c and 4 provide an overview of synthesis route for each of the example and comparative examples : compared to prior art, the process of the disclosure has the additional advantage to achieve incorporation of Al, B and W elements in the CAM with only two heat treatment steps. 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 not be 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 examples should be considered as available for other similar features or aspects of other examples.

Claims

CLAIMS 1. A process for manufacturing a cathode active material powder comprising Li, O, M’, wherein M’ includes Al, B, W, Mn, Co, and Ni, Ni being included in M’ in a content of at least 60.0 at% and of less than 80.0 at%, or at least 60.0 at% and at most 70.0 at%, or at least 65.0 at% and of at most 75.0 at%, relative to M’ as measured by ICP-OES, said process comprising: - a first step of mixing a precursor of the cathode active material with a Li source, a first source of Al and optionally, a Zr source, to obtain a first mixture powder, - a second step of heat treating the first mixture powder, optionally under oxidizing atmosphere, at a first temperature of at least 800°C and at most 1000°C, thereby obtaining a first fired material, - a third step of milling the first fired material, thereby obtaining a first intermediate powder, - a fourth step of mixing the first intermediate powder with a second source of Al, a B source, and a W source, thereby obtaining a second mixture powder, - a fifth step of either: o mixing the second mixture powder with a third source of Al and with water, or o mixing the second mixture powder with an aqueous source of Al, thereby obtaining a third mixture, - a sixth step of heat treating the third mixture, optionally under oxidizing atmosphere, at a second temperature of at least 300°C and of at most 500°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.

2. The process according to claim 1, wherein in the seventh step, a fourth source of Al is added to the second fired material during grinding.

3. The process according to claim 1 or 2, wherein M’ comprises: - Ni in a content x, wherein 60.0 at% ≤ x < 80.0 at%, or 65.0 at% ≤ x ≤ 75.0 at%, or 60.0 at% ≤ x ≤ 70.0 at%, relative to M’, - Mn in a content y, wherein 20.0 at% ≤ y ≤ 30.0 at%, relative to M’, - Co in a content z, wherein 5.0 at% ≤ z ≤ 8.0 at%, relative to M’,- Al in a content a, wherein 0.4 at% < a ≤ 0.80 at%, relative to M’, - Zr in a content b, wherein 0.0 at% ≤ b ≤ 0.50 at%, relative to M’, - B in a content c, wherein 0.2 at% < c ≤ 0.50 at%, relative to M’, and - W in a content d, wherein 0.05 < d ≤ 0.20 at%, relative to M’, wherein x+y+z+a+b+c+d is 100.0 at% as determined by ICP-OES.

4. The process according to any of the preceding claims, wherein the second step of heat treating the first mixture powder is performed at a first temperature of at least 900°C and at most 950°C.

5. The process according to any of the preceding claims, wherein the second step of heat treating the first mixture powder is performed during a first time period of at least 9 hours and at most 10 hours.

6. The process according to any of the preceding claims, wherein the sixth step of heat treating the third mixture is performed at a second temperature of at least 350°C and at most 390°C.

7. The process according to any of the preceding claims, wherein the sixth step of heat treating the third mixture is performed during a second time period of at least 6 hours and at most 8 hours.

8. The process according to any of the preceding claims, wherein the Li source is LiOH or Li2CO3.

9. The process according to any of the preceding claims, wherein the Zr source is at least one of: ZrO2, ZrH2, ZrF4, ZrN, Zr(NO3)4, ZrCl4, ZrC, and Zr(OH)4.

10. The process according to any of the preceding claims, wherein the B source is at least one of : H3BO3, BN, B4C, and B(OH)3. 11.The process according to any of the preceding claims, wherein the W source is at least one of : WO3, WO2, W2N, and WCl6.12.The process according to any of the preceding claims, wherein any of the first, second and fourth sources of Al is at least one of: Al2O3, AlOOH, AlN, Al(NO3)3, AlCl3, and AlF3.

13. The process according to any of the preceding claims, wherein the third source of Al is Al2(SO4)3.

14. The process according to any of the preceding claims, wherein the aqueous source of Al is an aqueous solution of Al2(SO4)3. 15.The process according to any of the preceding claims, wherein the third step of milling is performed with a jet miller.

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