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 a process for manufacturing a cathode active material or positive electrode active material (hereafter referred to as CAM) comprising Al, B and W elements. 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.

[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 apredetermined period of time. The CAM from the process according to the present disclosure is suitable to be used in Li-ions secondary batteries. BACKGROUND

[0004] A process for manufacturing 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).

[0005] The process disclosed in EP’437 includes three heat treatment steps. More specifically, it comprises : - a first step of mixing a Ni0.68Mn0.27Co0.05(OH)2as 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 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 H3BO3, so as to obtain a third mixture that is subsequently heat treated at 375°C during 7 hours, and- a final step of grinding and sieving with Al2O3.

[0006] The CAM from the process of EP’437 has low initial charge and discharge capacities (hereafter respectively referred to as CQ1 and DQ1), and may lead to high IRRQ.

[0007] It is therefore an object of the present disclosure to provide a process which leads to a CAM with improved electrochemical (hereafter referred to as EC) properties. SUMMARY OF THE DISCLOSURE

[0008] This first object is achieved by providing a process according to claim 1.

[0009] 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 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 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, or of at least 900°C and 950°C, - 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 first source of Al, thereby obtaining a second mixture powder, - a fifth step of heat treating the third mixture, optionally under oxidizing atmosphere, at a second temperature of at least 700°C and of at most 900°C, or of at least 750°C and at most 800°C, thereby obtaining a second fired material,- a sixth step of grinding and sieving the second fired material, thereby obtaining a second intermediate powder, - a seventh step of mixing the second intermediate powder with a B source, a W source, thereby obtaining a third mixture powder, - an eighth step of heat treating the third mixture at a temperature of at least 300°C and at most 500°C, or of at least 350°C and at mots 400°C, thereby obtaining a third fired material, and - a ninth step of grinding and sieving the third fired material to obtain the cathode active material, wherein during the fourth step, and optionally the seventh step, no more Li source is added to the first intermediate powder (and optionally to the second intermediate powder).

[0010] 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 and 2.

[0011] Compared to prior art, the process according to the disclosure does include only one Li source addition during the first step, whereas the process according to EX1 of EP’437 (hereafter referred to as CEX1) contemplates usage of several Li sources for manufacturing the CAM.

[0012] The process according to the disclosure includes the following aspects:

[0013] Optionally, during the fourth and seventh steps, no more Li source is added to the first and second intermediate powders.

[0014] Optionally, during the eighth step, no more Li source is added to the third mixture powder.

[0015] 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%.

[0016] In the sixth step, a second source of Al maybe added to the second fired material during grinding. The second Al source can be replacedor added in combination with by at least any of a Si (like SiO2) or W source (like WO3).

[0017] In the fourth step, a Co source may be mixed with the first intermediate powder and with the first source of Al, and wherein the second mixture powder may include Al and Co.

[0018] In the fourth step, a Zr source may be mixed with the first intermediate powder and with the first source of Al, and wherein the second mixture powder may include Al and Zr.

[0019] In the fourth step, a Zr source may be mixed with the first intermediate powder and with the first source of Al and a second source of Co, and wherein the second mixture powder may include Al, Co, and Zr.

[0020] Optionally, the second step of heat treating the first mixture powder can be performed at a first temperature of at least 900°C and at most 950°C.

[0021] The second step of heat treating the first mixture powder may be performed during a first time period of at least 9 hours and at most 10 hours.

[0022] The fifth step of heat treating the third mixture may be performed at a second temperature of at least 750°C and at most 800°C.

[0023] The fifth 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.

[0024] The Li source can be at least one of LiOH or Li2CO3.

[0025] The Zr source can be at least one of ZrO2, ZrH2, ZrF4, ZrN, Zr(NO3)4, ZrCl4, ZrC, Zr(OH)4.

[0026] The B source can be at least one of H3BO3, B2H6, BN, B4C, B(OH)3, an BH3O3.

[0027] The W source can be at least one of WO3, WO2, WN, W2N, WN2, WCl6, and WC.

[0028] Any of the previously mentioned Al sources can be at least one of Al2O3, AlOOH, AlN, Al(NO3)3, AlCl3, and AlF3.

[0029] The third step of milling may consist of jet milling the first fired material.

[0030] 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 at 3000 rpm (revolution per minute) at a room temperature. Jet milling conditions can be adjusted to achieve D50 values according to disclosure.

[0031] 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).

[0032] The first mixture can have a (at% / at%) ratio of CLi / (∑i=ni=1 Ei ) of atleast 1.00 and of at most 1.10, or equal to 1.05 ± 0.05 as determined by ICP-OES, wherein CLi(expressed in at%) is a Li content in the first mixtureand Ei is a sum of individual content Ei (expressed in at%) of each of theelements 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.

[0033] 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 isa sum of individual content E’i(expressed in at%) of each of the elements different than Li in the first mixture. E’iis either 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.

[0034] 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).

[0035] 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.

[0036] 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 be of 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.

[0037] 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.

[0038] Al, Zr, W, B, and Si can be encompassed in a group of elements Q.

[0039] 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.

[0040] 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 can be added to the mixture including the pCAM, the Li source and optionally the at least one Q source.

[0041] The cathode active material according to the disclosure may include more elements than Li, M and O. Additional elements can be forinstance 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.

[0042] 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.

[0043] 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, forinstance wherein the atomic planes of the two primary particles are aligned to different orientations and meet as a crystalline discontinuity.

[0044] Single particles are grain free and each of them consists of solely one standalone particle.

[0045] 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

[0046] The following analysis methods are used in the Example and the Comparative Example. A) ICP-OES measurement

[0047] 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.

[0048] 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 beconverted from a given wt% of said first element E1(Ewt1) in said material by applying the following formula,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)

[0049] The particle size distribution (hereafter referred to as PSD) of the positive electrode active material is measured by laser scattering method using a Malvern Mastersizer 3000 with a Hydro MV wet dispersion accessory after having dispersed each of the powder samples in an aqueous medium. In order to improve the dispersion of the powder, sufficient ultrasonic irradiation and stirring are applied, and an appropriate surfactant is introduced. PSD may be represented by D50 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

[0050] The specific surface area is measured with the Brunauer- Emmett-Teller (BET) method using a Micromeritics Tristar 3000.2g of material powder sample is first dried in an oven at 120°C for 2h, followed by N2 purging. Then the oven is degassed in vacuum at 120ºC for 1 hour prior to the measurement, in order to remove adsorbed speciesD) X-ray diffraction (XRD) measurement

[0051] 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.

[0052] The peak of the (104) plane is observed at (around) 44.5±1° and (003) peak observed at (around) 18.6±1° which are assigned to a crystal structure with space group R-3m. E) pH titration-soluble base content measurements

[0053] 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.

[0054] 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 withendpoint γ2 (in mL) included in a range of pH values between 4 and 6 is associated to HCO3- / H2CO3couple. The inflection points between the 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.

[0055] Results are then expressed in LiOH and Li2CO3weight percent as follows:23.9483 ^^^^^^^^^^^^^^^^ ^^^^^^^^% =1000× (2 × ^^^^1 − ^^^^2);F) Full cell testing F-1) Full cell preparation

[0056] 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.

[0057] 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 servingas 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.

[0058] Non-aqueous electrolyte is obtained by dissolving lithium hexafluorophosphate (LiPF6) 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 (LiPO2F2), and 1.0 wt.% vinylene carbonate (VC) as additives.

[0059] 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 to 4.25 V for a first set of data and to 4.35 V for a 2ndset of data, respectively. The full cell testing procedure uses a 1 C current definition of 2000 mA / g. F-2) Cycle life test A. Pre-charging and formation

[0060] 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.

[0061] The battery is charged with a current of 0.2 C in CC mode (constant current) up to 4.25V and 4.35 V and CV mode (constant voltage) until a cut-off current of C / 20 is reached. The battery is discharged with acurrent 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 4.25V and 4.35 V and CV mode until a cut-off current of C / 20 is reached.

[0062] 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 4.25V 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

[0063] 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 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.

[0064] 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.

[0065] The cycle life is defined as the number of charge-discharge cycles when the capacity degrades to 80%. F-3) Bulging test

[0066] 650mAh pouch-type batteries prepared by above preparation method are fully charged until 4.25V and 4.35V 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

[0067] The present disclosure is further illustrated in the following examples and comparative examples.

[0068] Tables 1 and 2 provide a summary of the EC performances of the (C)EXs whereas in Table 3, physicochemical properties of the CAM’s according to the EX1 and prior art (CEX1) are provided. Example 1 (EX1)

[0069] A positive electrode active material EX1 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 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 Al2O3 powder , and 0.25 mol% of Zr (Zr to metal (Ni, Mn, Co) atomic ratio of 0.0025) from ZrO2 powder to obtain a second mixture. 4) Second heating: The second mixture obtained from step 3) is heated at 775°C followed by crushing and sieving process together with alumina (Al2O3) powder, thereby obtaining a second heated powder.

[0070] 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 sieving process together with alumina (Al2O3) powder to obtain a positive electrode active material powder EX1.

[0071] In any of the above-mentioned (C)EXs, 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.

[0072] Table 1c provides ppm and at% contents of additives for EX1. 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). 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.***gn7ig%.l 8 u B * **l.lf0f%.7 ec E8 lluF 1 g / h9.Q A 8 D 8 m 1 1g / h0.Q 7 C A 1 m 2*l*l*3ecgn9i.8.0 ll%5 5W1. ug0 Fl2 1uB 3 B54.0l0A5.0)%ta(2n o’ r 2tM Z.i01isXoEp 1X Ee mh o0t coC8. ehfM6toAfCosescn1ecan6 nmM.5ar 2morforfer 7pe 30p 41X1Ci3’EN.6V5 CPEXEs’ 603. srEEVs5’2sM0 4uo .M4 ruA’1* tahAn oC:M 1 ) t 0Cith / a i0L.1 s1Qe2 : s 01Ce / t re 2eetb1trelb 1 1lcfa XQya elelctE Dyfa(c * bacT ***** T ***5**t tnds eO o Nespmtaaber§t ;) t%234.1.O0 l 2ntua * 0Ao(gnimea m §crxipp 0000u50oM2sdr slA 3evit) i3)f3od O B B O daH3W W m ((pp*0t0tn 5sego*Snipmta EYseurtdetc*udt % nt 527 0 n.1.0 oua 0 0.2cosga1nm§w i AXxim p0 tnE-0- ero dmp 5mtf n2saot eev) )rte i)r tir 2 l 3 4OtZOed rAO l2 o 3 shd ZCo(A C oPta ( (*d*et *;t)annlMetrs eO+t o mt * on paN Cueort+iN(ma*.sdnt%vt danua etse g o alvinimxa § umcltiipOaMdmpNcAdtser Caf1sefooev wtt itt hsii ld negie: dcar wcepla1citoetlbD1IXmnaEot oTa*pu5Table 2: CAM’s EC performances of the EX1, CEX1 and EP’437 CAM composition (at%)ECM’ CQ1 DQ1 IRRQ* Ni mAh / g mAh / g % EX1 66.3 217.0 188.9 12.90 EP’437 66.5 201.16 173.3 13.92 EX1** *IRRQ(%) = 100%*(CQ1-DQ1) / CQ1 **EX1 of EP’437 is CEX1 in the present disclosure

[0073] CAM powder according to the disclosure allows reduced bulging and increased safety.

[0074] 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 66 at% and no more than 66.5 at%).)S S3)3O g WhO n: 7Wh7it e+C° : :e +C° :a r 3O5 ne utB7 oiMr 3utO5 nB7 oiM dhx33:tA Cx33tA C riHaiH: a+3 r 2 r3 M2Tu M +Tu _tD2_D ntIn(I(*)S *O2)SrO2Z r + Z4+ O3h g ni : 4hOC8 : oCC2 te3 ° °1 areuo5:7n2e+ o_ru35:2 7n _dh tC xni+37 i:t t t Oan xi l 27o:ittn2 MOl 2 2 r IA M2aIrATu + D HTu + OiD 1_tLn+ I(1_tnI(gnillims1 e_s1 _s tY te et j n eIY tnIuyorrDsisehth hnygsni:H teOC 0i° 1 :H :eOC 0i° 1:es1aruL5Xe t+2n0r L5o_tu+2n0 o_tahE th xiM9: itntIxiM9: itnIesp-sCsA 1 MC1arA1ard p Tu MCp Tuah uponD D- eadiulq1 oaXs sE sna: 7n3ae3 1X41 emelE ’XEm”bPE ” L“aST”***5

[0075] Table 3 provides an overview of synthesis route for each of the examples and comparative examples. Compared to prior art, EX1 of the disclosure has the following advantages: i) It allows production of CAM with improved EC performances as demonstrated in Table 2; and ii) It bears lower costs because it allows easier production since the 2ndheating step is performed without additional Li source and at a shorter duration (e.g. at most 8 hours versus 12 hours according to process of EX1 of EP’437).

[0076] 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 present 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 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 first source of Al, thereby obtaining a second mixture powder, - a fifth step of heat treating the third mixture, optionally under oxidizing atmosphere, at a second temperature of at least 700°C and of at most 900°C, thereby obtaining a second fired material, - a sixth step of grinding and sieving the second fired material, thereby obtaining a second intermediate powder, - a seventh step of mixing the second intermediate powder with a B source, a W source, thereby obtaining a third mixture powder, - an eighth step of heat treating the third mixture at a temperature of at least 300°C and at most 500°C, thereby obtaining a third fired material, and - a ninth step of grinding and sieving the third fired material to obtain the cathode active material, wherein during the fourth step, no more Li source is added to the first intermediate powder.

2. The process according to claim 1, wherein in the sixth step, a second 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 in the fourth step, a Co source and / or a Zr source is mixed with the first intermediate powder and with the first source of Al, and wherein the second mixture powder includes Al and Co.

5. The process according to any of claims 1 to 3, wherein in the fourth step, a Zr source is mixed with the first intermediate powder and with the first source of Al, and wherein the second mixture powder includes Al and Zr.

6. The process according to any of claims 1 to 3, wherein in the fourth step, a Zr source is mixed with the first intermediate powder and with the first source of Al and a second source of Co, and wherein the second mixture powder includes Al, Co, and Zr.

7. 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.

8. 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.

9. The process according to any of the preceding claims, wherein the fifth step of heat treating the third mixture is performed at a second temperature of at least 750°C and at most 800°C.

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

11. 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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