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

Abstract

A cathode active material powder compound having a formula: LiaNixMnyCOzCacSdQbBwO2, wherein : - 90.00 at% ≤ a ≤ 110.00 at%, - 70.00 at% < x ≤ 95.00 at%, - 0.0 at% < y ≤ 10.00 at%, - 0.0 at% ≤ z ≤ 15.00 at%, - 0.00 at% < c ≤ 0.75 at%, - 0.040 at% ≤ d ≤ 0.75 at%, - 0.00 at% < w ≤ 0.75 at%, and - 0.00 at% ≤ b ≤ 2.75 at%, with x+y+z+b+c+d+w = 100.00 at% as determined by ICP-OES, wherein Q is at least one element of a list consisting of: Na, Mg, Zr, Nb, W, Si, Ba, Sr, Zn, Cr, V, Y, Sb, Ta, Mo, Ti, wherein the cathode active material powder has a specific surface area of more than 0.50 m2 / g and of at most 0.75 m2 / g as determined by BET analysis.

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 or powderous CAM is also referred hereunder as NMC (NiMnCo) CAM powder. The terms 'CAM' and 'CAM powder', or 'powderous CAM' 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 term "consisting of".

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

[0004] In particular, the present disclosure relates to a NMC CAM containing a high content of Ni, hereafter referred to as hNMC. For instance, a hNMC CAM comprises a Ni / (Ni + Mn+Co) ratio of at least 70.0 at% / at% (e.g. NMC712) or 80.0 at% / at% (e.g., NMC811). In the present disclosure, "at%" signifies atomic percentage. The at% or "atomic percent" of a given element means a percentage of atoms of said element among all atoms in a claimed composition. at% can be measured by inductively coupled plasma - optical emission spectrometry (hereafter referred to as ICP-OES).

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

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

[0007] hNMC CAMs and methods of manufacturing thereof are known. For example, each of CN111422916A (hereafter referred to as CN'916) or WO2023 / 274867 (hereafter referred to as WO'867) discloses a method for manufacturing a hNMC CAM including a first step of mixing a pCAM and a Li source to obtain a mixture, a second step of heat treating (or sintering) the mixture followed by grinding to obtain a sintered material powder including particles, each of the particles having a surface, and a third step of subjecting the sintered material powder to a water-based washing treatment during which the surface of the sintered material particles is put into contact with an aqueous solution.

[0008] Conventionally, this washing treatment is carried out to reduce a concentration of residual alkali present at the surface of the sintered material particles. Residual alkali are for instance LiOH and / or U2CO3. These compounds are undesired and their content should be minimized. For instance, as mentioned in US9698418 (hereafter referred to as US'418), presence of U2CO3 in the CAM may lead to a poor slurry stability and an excessive bulging of the battery containing the CAM is observed. Also, US'418 explains that presence of LiOH tends to cause a poor slurry stability.

[0009] The washing treatment may alter electrochemical (hereafter referred to as EC) performances of CAMs. For instance, CAMs made according to above- mentioned process generally have high capacity fading rate (hereafter referred to as QF). QF is a parameter indicating a capacity fading after multiple charging and discharging cycles of a CAM embedded in a positive electrode of a battery. A low QFvalue means a good cycle life of the battery. Poor first discharge capacity (DQ1) is also observed for CAMs manufactured with a process including the washing treatment.

[0010] For instance, CN'916 contemplates a CAM that manufactured according to above-mentioned process and having a high QF of 20% / 100 cycles with a low DQ1 of 211.1 mAh / g. DQ1 of CAMs manufactured by washing treatment can be improved by adding B to their composition. In WO'867, several CAMs obtained from a washing-based process and containing B show improved DQ1 values.

[0011] Still, there is a need to further optimize hNMC CAM production.

[0012] Therefore, it is a first object of the present disclosure to provide a hNMC CAM having a lowered QF.

[0013] A second object of the disclosures includes a process for manufacturing the hNMC CAM according to the disclosure.

[0014] A third object of the disclosure relates to a battery including the CAM according to the disclosure.

[0015] The present disclosure relates to a cathode active material suitable for use in a (Li ion) rechargeable battery across a wide range of applications. Thus, a fourth object of the disclosure covers an electrically powdered device comprising the battery including the CAM according to the disclosure. The battery may be incorporated into an electrically powered device (hereafter referred to as EPD) that relates to various application:- Consumer electronic, wherein the EPD can be at least one of: a portable computer, a tablet, a mobile phone, and a telecommunication device. The integration of the battery of the disclosure into one of the above-mentioned consumer electronic devices may provide compact and lightweight energy sources that support high energy density and long operational life;- Industrial application, wherein the EPD can be at least one of a power tool, a mobile machinery, and a robotic device. The integration of the battery of the disclosure into one of the above-mentioned industrial devices may contribute to improved productivity and operational flexibility, because of high discharge rates and robust performances of ten battery of the disclosure;- Energy application, wherein the EPD can be at least one of an energy storage device (also called energy storage system) and an uninterruptible power supply device or system, thereby ensuring a stable and scalable energy management, supporting grid resilience and backup power reliability;- Transportation applications, wherein the EPD can be at least one of an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicles (pHEV), an extended-range electric vehicle (ER.EV), and a fuel cell electric vehicles (FCEV). Additionally, the EPD can be a two-wheeler transportation vehicle. Any of these vehicles may be designed for passenger or freight transport and may operate on ground, rail, marine, aerospace, or aviation platforms. These applications benefit from the battery's ability to deliver consistent power output, fast charging capability, and thermal stability;- Further applications, wherein the EPD can be a defence device or a medical device. The battery of the disclosure may provide a secure and uninterrupted power for mission-critical systems, where reliability, compactness, and energy density are paramount. The cathode active material of the disclosure used in the battery contributes to enhanced cycle life, reduced degradation, and improved electrochemical stability, thereby extending the operational lifespan of the devices and systems in which it is deployed.

[0016] Therefore, the EPD of the disclosure (including the battery of the disclosure) may be selected from the group consisting of: a portable computer, a tablet, a mobile phone, a telecommunication device, a power tool, mobile machinery, a robotic device, an energy storage system, an uninterruptible power supply system, an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an extended-range electric vehicle, a fuel cell electric vehicle, a two-wheeler transportation vehicle, a rail vehicle, a marine vehicle, an aircraft, an aerospace system, a defence device, and a medical device.

[0017] In particular, the 4thobject covers an electric vehicle (EV) or a (plugin) hybrid electric vehicle ((p)HEV) including the battery according to the disclosure.

[0018] A fifth object of the disclosure covers the use of the battery according to the disclosure and comprising the cathode active material of the disclosure in an EPD. The EPD is optionally selected from the group consisting of: a portable computer, a tablet, a mobile phone, a telecommunication device, a power tool, mobile machinery, a robotic device, an energy storage system, an uninterruptible power supply system, an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an extended-range electric vehicle, a fuel cell electric vehicle, a two-wheeler transportation vehicle, a rail vehicle, a marine vehicle, an aircraft, an aerospace system, a defence device, and a medical device.SUMMARY OF THE DISCLOSURE

[0019] The first object of the disclosure is achieved by providing a cathode active material powder according to claim 1, having a formula:LiaNixMnyCOzCacSdQbBwO2, wherein :- 90.00 at% < a < 110.00 at%,- 70.00 at% < x < 95.00 at%,- 0.0 at% < y < 10.00 at%,- 0.0 at% < z < 15.00 at%,- 0.00 at% < c < 0.75 at%,- 0.00 at% < d < 0.75 at%, or 0.040 at% < d < 0.75 at%, or optionally:0.050 at% < d < 0.75 at%, or 0.55 at% < d < 0.75 at%,- 0.00 at% < w < 0.75 at%, and- 0.00 at% < b < 2.75 at%, with x+y+z+b+c+d+w = 100.00 at% as determined by ICP-OES, wherein Q is at least one element of a list consisting of: Na, Mg, Zr, Nb, W, Si, Ba, Sr, Zn, Cr, V, Y, Sb, Ta, Mo, Ti, wherein the cathode active material powder has a specific surface area (also referred as to SSA) of more than 0.50 m2 / g and of at most 0.75 m2 / g as determined by BET analysis.

[0020] Alternatively, the CAM powder has a formula : LiaNixMnyCOzCacSdQbBwO2, wherein :- 90.00 at% < a < 110.00 at%,75.0 at% < x < 85.0 at%,3.0 at% < y < 6.0 at%, and5.0 at% < z < 14.0 at%0.00 at% < c < 0.75 at%,0.00 at% < w < 0.75 at%,0.040 at% < d < 0.75 at%, or optionally: 0.050 at% < d < 0.75 at%, and- 0.00 at% < b < 2.75 at%, with x+y+z+b+c+d+w = 100.00 at% as determined by ICP-OES, wherein Q is at least one element of a list consisting of: Na, Mg, Zr, Nb, W, Si, Ba, Sr, Zn, Cr, V, Y, Sb, Ta, Mo, Ti,wherein the cathode active material powder has a specific surface area of more than 0.50 m2 / g and of at most 0.75 m2 / g as determined by BET analysis.

[0021] Alternatively:- 90.00 at% < a < 110.00 at%,- 70.00 at% < x < 95.00 at%,- 0.0 at% < y < 10.00 at%,- 0.0 at% < z < 15.00 at%,- 0.00 at% < c < 0.75 at%,- 0.55 at% < d < 0.75 at%,- 0.00 at% < w < 0.75 at%, and- 0.00 at% < b < 2.75 at%, with x+y+z+b+c+d+w = 100.00 at% as determined by ICP-OES

[0022] Alternatively, the CAM powder has a formula : LiaNixMnyCOzCacSdQbBwO2, wherein :- 90.00 at% < a < 110.00 at%,75.0 at% < x < 87.0 at%,3.0 at% < y < 6.0 at%, and5.0 at% < z < 14.0 at%0.00 at% < c < 0.75 at%,0.00 at% < w < 0.75 at%,0.040 at% < d < 0.75 at%, or optionally: 0.050 at% < d < 0.75 at%, and- 0.00 at% < b < 2.75 at%, with x+y+z+b+c+d+w = 100.00 at% as determined by ICP-OES, wherein Q is at least one element of a list consisting of: Na, Mg, Zr, Nb, W, Si, Ba, Sr, Zn, Cr, V, Y, Sb, Ta, Mo, Ti, wherein the cathode active material powder has a specific surface area of more than 0.50 m2 / g and of at most 0.75 m2 / g as determined by BET analysis, and a D50 of at least 1.5 pm and of at most 20 pm.

[0023] It is indeed observed that the CAM according to claim 1 allows a decrease of QF, as illustrated in the present disclosure. Additionally

[0024] In one aspect of the CAM compound according to the present disclosure:- 75.0 at% < x < 85.0 at%,- 3.0 at% < y < 6.0 at%, and- 5.0 at% < z < 14.0 at%.

[0025] Optionally, 95.00 at% < a < 105.00 at%.

[0026] Optionally: 0.050 at% < d < 0.75 at%.

[0027] Alternatively:- 75.0 at% < x < 85.0 at%,- 3.0 at% < y < 6.0 at%,- 7.20 at% < z or 10.65 at% < z,- z < 14.0 at%,- 0.00 at% < c < 0.75 at%,- 0.00 at% < d + b < 3.50 at%, or 0.050 at% < d + b < 3.50 at%,- 0.55 at% < w < 0.75 at%, and wherein :- 0.00 at% < b < 2.75 at%, with :- 0.00 at% < d < 0.75 at% or 0.050 at% < d < 0.75 at%.

[0028] Alternatively:- 75.0 at% < x < 85.0 at%,- 3.0 at% < y < 6.0 at%,- 7.20 at% < z or 10.66 at% < z,- z < 14.0 at%,- 0.00 at% < c < 0.75 at%,- 0.00 at% < d + b < 3.50 at%, or 0.040 at% < d + b < 3.50 at%,- 0.55 at% < w < 0.75 at%, and wherein :- 0.00 at% < b < 2.75 at%, with :- 0.040 at% < d < 0.75 at%.

[0029] The cathode active material powder may have a content of Ca is of at least 0.45 at% and of at most 0.65 at% as determined by ICP-OES. Alternatively, the content of Ca is of at least 0.50 at% as determined by ICP-OES.

[0001] The CAM powder may have S in a content of at least 0.55 at% and at most 0.75 at% or of at least 0.65 at% and at most 0.70 at% as determined by ICP- OES. Furthermore, the S content in the CAM powder can be of :- 0.00 at% < d < 0.75 at%, or of:- 0.01 at% < d < 0.75 at%, or of:- 0.02 at% < d < 0.75 at%, or of:- 0.03 at% < d < 0.75 at%, or of:- 0.04 at% < d < 0.75 at%, or of:- 0.05 at% < d < 0.75 at%, or of:- 0.04 at% < d < 0.10 at%, or of:- 0.00 at% < d < 0.20 at%, or of:- 0.01 at% < d < 0.15 at%, or of:- 0.02 at% < d < 0.10 at%, or of:- 0.03 at% < d < 0.10 at%, or of:- 0.04 at% < d < 0.10 at%, or of:- 0.05 at% < d < 0.10 at%.

[0002] In a second aspect of the CAM according to the disclosure, the CAM powder has a specific surface area of at most 0.65 m2 / g. The CAM powder may have a specific surface area of at least 0.60 m2 / g.

[0003] In a third aspect of the cathode active material powder according to the disclosure, S is present in a content of at least 0.040 at%.

[0004] Optionally, S maybe present in a content of at most 0.050 at%.

[0005] In a fourth aspect of the cathode active material powder according to the disclosure, B is present in a content w of at least 0.55 at% and of at most 0.65 at% or of at least 0.60 at% and of at most 0.65 at% as determined by ICP-OES.

[0006] Furthermore, the CAM of the disclosure may be expressed according to the following formula: LiaNixMnyCOzCacSdQbBwC , wherein: 0.90 < a < 1.10, 0.70 < x < 0.95, 0.0 < y < 0.10, 0.00 < z < 0.15, 0.00 < c < 0.0075, 0.00 < d < 0.0075, 0.00 < w < 0.0075, and 0.00 < b < 0.0275, wherein x+y+z+c+d+b+w=1.00. Optionally, 0.95 < a < 1.05.

[0007] x+y+z+b+c+d+w = 1.00 mol% / mol% or = 1.00 mole (or mol.) or = 1.00 at% / at% or 1.00 atom (or at.). Optionally : 0.95 at% / at% < a < 1.05 at% / at%.

[0008] Optionally: 0.75 < x < 0.85, 0.03 < y < 0.06, and 0.05 < z < 0.14.

[0009] Alternatively, the CAM powder has the formula :LiaNixMnyCOzCacSdQbBwO2, and :- 0.75 < x < 0.85,- 0.03 < y, and y < 0.06,- 0.05 < z < 0.14,- 0.00 < c < 0.0075,- 0.00 < d + b < 0.035,- 0.00 < w < 0.0075, and 0.00 < d < 0.0075, and wherein:- 0.00 at% < b < 0.0275, with x+y+z+b+c+d+w = 1.00 mo% / mol%.

[0010] Optionally : 0.00040 < d < 0.0075 or 0.00050 < d < 0.0075.

[0011] Alternatively, the CAM compound powder composition can have a formula : LiaNixMnyCOzCacSdQbBwC wherein:- 0.75 < x < 0.85,- 0.0450 < y < 0.06,- 0.0916 < z < 0.14,- 0.0055 < c < 0.0075,- 0.00040 < d < 0.0075,- 0.00040 < d + b < 0.035,- 0.00 < w < 0.0075, and:- 0.00 < b < 0.0275, with x+y+z+b+c+d+w = 1.00 mo% / mol%.

[0012] Alternatively:- 0.75 < x < 0.85,- 0.0395 < y < 0.06,- 0.0916 < z < 0.14,- 0.0055 < c < 0.0075,- 0.00040 < d < 0.0075,- 0.00040 < d + b < 0.035,- 0.0055 < w < 0.0075, and:- 0.00 < b < 0.0275, with x+y+z+b+c+d+w = 1.00 mo% / mol%.

[0013] In a fifth aspect of the disclosure, cathode active material has a BXPS value of more than 0.00 and of less than 1.00. This value of BXPS can be of at least 0.50 and of no more than 0.70. Alternatively, this value of BXPS can be of at least 0.60 and of no more than 1.00.

[0014] In a sixth aspect of the disclosure, cathode active material has a median particle size D50 of at least 1.5 pm or of at least 2.0 pm or of at least 3.0|jm.

[0015] Optionally, the D50 is of at most 20.0 pm.

[0016] Alternatively:- 1.0 pm < D50 < 20.0 pm; or- 1.0 pm < D50 < 15.0 pm; or- 1.0 pm < D50 < 10.0 pm : or- 1.0 pm < D50 < 5.0 pm; or- 1.50 pm < D50 < 20.0 pm; or- 1.50 pm < D50 < 15.0 pm; or- 1.50 pm < D50 < 10.0 pm; or- 1.50 pm < D50 < 5.0 pm; or- 2.50 pm < D50 < 20.0 pm; or- 2.50 pm < D50 < 15.0 pm; or- 2.50 pm < D50 < 10.0 pm; or- 2.50 pm < D50 < 5.0 pm.

[0017] Optionally, 3.0 pm < D50.

[0018] The CAM powder may have at least one distinct peak in a range of 20 = 37.5±0.5° or in a range of at least 37.0° and at most 38.0°, wherein a peak intensity ratio of the distinct peak over a (101) peak at 20 = 36.5° is equal to or higher than 0.010 and lower than 0.100, as measured by X-ray diffraction measurement using a Cu-Ko radiation source.

[0019] The at least one distinct peak can be indexed as a Ca oxide compound- related peak, the Ca oxide compound-related peak being possibly associated to CaO.

[0020] The CAM powder may have a Li / M" (at% / at%) ratio of at least 0.90 and at of most 1.10, or of at least 0.95 and of at most 1.00, or of at least 0.99, as determined by ICP-OES. In this ratio, M" = NixMnyCoz.

[0021] The CAM may be an Al-free CAM.Process for manufacturing the CAM oowder

[0022] The second object of the disclosure is a process for manufacturing the CAM powder according to the disclosure comprising:- a step of providing a precursor of the cathode active material,- a step of providing a Li source, a Ca source, and optionally at least one Q source, the at least one Q source including at least one of the following elements: Na, Mg, Zr, Nb, W, Si, Ba, Sr, Zn, Cr, V, Y, Sb, Ta, Mo, Ti,- a step of mixing the precursor, the Li source, the Ca source, and optionally the at least one Q source together to obtain a first mixture,- a step of subjecting the first mixture to a first heat treatment under an oxidizing atmosphere at a first temperature of at least 400 °C and at most 900 °C for a first duration of at least 5 hours to at most 20 hours to obtain a first heated material,- a step of crushing and sieving the first heated material into a crushed material powder,- a step of mixing the crushed material powder with a water-based liquid wherein the weight ratio of water over the crushed material powder is higher than or equal to 20% to obtain a slurry,- a step of removing water from the slurry by filtering it to obtain a filtered powder,- a step of drying the filtered powder to obtain a dried powder, and- a step of mixing the dried powder with a B source to obtain a second mixture,- a step of subjecting the second mixture to a second heat treatment under an oxidizing atmosphere at a second temperature of at least 100 °C and at most 500 °C for a second duration of at least 1 hour to at most 10 hours.

[0023] The (first) temperature of the first heat treatment can be of at least 700 °C and at most 850 °C, or of at least 750 °C and at most 800 °C, or even of at least 780 °C and at most 850 °C, or of at least 780 °C and at most 800 °C.

[0024] The (first) duration of the first heat treatment can be of at least 6 hours and at most 8 hours.

[0025] The (second) temperature of the second heat treatment can be of at least 250 °C and at most 350 °C.

[0026] The (second) duration of the second heat treatment can be of at least 6 hours and at most 8 hours.

[0027] A step of sieving of the dried powder can be performed before the step of mixing the dried powder with a B source to obtain a second mixture.

[0028] The oxidizing atmosphere in the first and second heating treatment steps is an oxygen based atmosphere. It can be air.

[0029] The 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 may include S.

[0030] The pCAM may include S and Na and / or Mg, respectively from raw NaOH and sulfate(s) of Ni, Mn and Co. A pCAM including S can be reacted with the Li source, as described above, thereby obtaining the CAM that includes these elements.

[0031] The precursor of the cathode active material may include Ni, Mn, Co and optionally S.

[0032] The pCAM can be an oxidized hydroxide precursor. Such an oxidized hydroxide precursor may be expressed as M"-0x(0H)2-x with 0<x<2 and M" including at least one of the following elements: Ni, Mn, Co, and optionally S.

[0033] Presence of Ni, Mn, Co and S in the pCAM can be detected by ICP-OES.Battery including the CAM powder and vehicle including the battery

[0034] 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 button) cell. Section D below provide a non-limitative embodiment of a coin cell. The battery can be a cylindrical, a prismatic or a pouch cell.

[0035] The battery can be incorporated in a vehicle.FIGUREFigure 1. : XRD pattern of the CAM powder according to EXIDETAILED DESCRIPTION OF THE DISCLOSUREEXPERIMENTAL ANALYSIS USED IN THE EXAMPLES AND THECOMPARATIVE EXAMPLE

[0036] The following analysis methods are used in the Example (EX) and the Comparative Examples (CEXs).A) Inductively Coupled Plasma Optical Emission Spectrometry (ICP- OES) measurements

[0037] The amount of Li, Ni, Co, Mn, Ca, S, and B in the cathode active material powder is measured with the ICP-OES method by using an Agilent ICP 720-ES (Agilent Technologies). 2.0 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.

[0038] 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 Eawiis a standard atomic weight (or molecular weight) of the first element Ei, Ewti is wt% of an ithelement Ei, Eawiis a standard atomic weight (molecular weight) of said ithelement , and n is an integer which represents the number of types of all elements included in the material.B) X-ray Photoelectron Spectroscopy (XPS) measurement

[0039] The surface of the cathode active material powder is analyzed by using X-ray photoelectron spectroscopy (XPS). In XPS measurement, the signal is acquired from the first few nanometers (e.g. 1 nm to 10 nm) of the uppermost part of a sample, i.e. surface layer. Therefore, all elements measured by XPS are contained in the surface layer.

[0040] For the surface analysis of the cathode active material powder particles, XPS measurement is carried out using a Nexsa G2 surface analysis system (Thermo Scientific, https: / / www.thermofisher.com / kr / ko / home / electron- microscopy / products / xps-instruments / nexsa.html). Monochromatic Al Ko radiation (hv=1486.6 eV) is used with a spot size of 400 pm and measurement angle of 45°. A wide survey scan to identify elements present at the surface is conducted at 200 eV pass energy. Cis peak having a maximum intensity (or centered) at a binding energy of 284.8 eV is used as a calibrate peak position after data collection. Accurate narrow-scans are performed afterwards at 50 eV for at least 10 scans for each identified element to determine the precise surface composition.

[0041] Curve fitting is done with CasaXPS Version2.3.25PR1.0 (Casa Software, http: / / www.casaxps.com / ) using a Shirley-type background treatment and Scofieldsensitivity factors. The fitting parameters are according to Table 2a. Line shape GL(30) is the Gaussian / Lorentzian product formula with 70 % Gaussian line and 30 % Lorentzian line. GL(30)T(k) is Gaussian / Lorentzian product formula modified by the exponential blend. Table la. XPS fitting parameter for Ni2p3, Mn2p, Co2pl, Bls, and Ca2p.

[0042] For Ni, Mn, Co, Ca, B peaks, constraints are set for each defined peak according to Table lb.Table lb. XPS fitting Constraints for Ni, Mn2p, Co2p, Bls, and Ca2p.

[0043] The B surface contents (BXPS) as determined by XPS is expressed as a atomic content of B in the surface layer of the particles divided by the total content of Ni, Co, Mn, B, and Ca in said surface layer. It is calculated as follow:

[0044] The information of XPS peak position can be easily obtained in the regions and components report specification after fitting is conducted.C) Brunauer-Emmett-Teller (BET) measurement

[0045] The specific surface area is measured with the Brunauer-Emmett- Teller (BET) method using a Micromeritics Tristar 3000. 2.0 g of precursor powder sample is first dried in an oven at 120 °C for 2 hours, followed by N2 purging. Then the precursor is degassed in vacuum at 120 °C for 1 hour prior to the measurement, in order to remove adsorbed species. A higher drying temperature is not recommended in precursor BET measurements, since a precursor may oxidize at relatively high temperature, which could result in cracks or nano-sized holes, leading to an unrealistically high BET.D) Coin Cell TestingD-l) Coin Cell preparation

[0046] For the preparation of a cathode, a slurry that contains a cathode active material powder, conductor (Li-435, ANP), binder (KF#9700, Kureha) - with a formulation of 96.22: 1.98: 1.8 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 170 pm gap. The slurry coated foil is dried in an oven at 120 °C and then pressed using a calendaring tool. Then it is dried again in a vacuum oven to completely remove the remaining solvent in the electrode film. A coin cell is assembled in an argon-filled glovebox. A separator (Celgard 2320) is located between a cathode and a piece of lithium foil used as an anode. IM LiPF6in EC / DMC (1 :2) + FEC is used as electrolyte and is dropped between separator and electrodes. Then, the coin cell is completely sealed to prevent leakage of the electrolyte.D-2) Testing Method

[0047] The testing method is a conventional "constant cut-off voltage" test. The conventional coin cell test in the present invention follows the schedule shown inTable 2. Each cell is cycled at 25 °C using a Toscat-3100 computer-controlled galvanostatic cycling station (from Toyo).

[0048] The schedule uses a 1C current definition of 200 mA / g in the 4.3 V to2.5 V / Li metal window range. The capacity fading rate (QF) at O.lC-rate is obtained according to below equation :QF (% / 100 cycles') = 100 100

[0049] The DQ6 and DQ33 are the discharge capacity of 6thand 33thcycle, respectively.Table 2. Cycling schedule for Coin cell testing methodE) X-ray diffraction (XRD) measurement

[0050] The X-ray diffraction pattern of the cathode active material is conducted by using a Bruker D8 Advance X-ray diffractometer (CuKo radiation = 1.5418 A) in the 20 range of 10-100° with a scan step of 0.015°. 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. A peak intensity ratio of a distinct peak at around 37.5°is calculated after removing a background baseline wherein the baseline is calculated using a straight background line from 20=35° to 20=40°.F) PSD measurement

[0051] A particle-size distribution (PSD) is measured by laser diffraction particle size analysis using a Malvern Mastersizer 3000 with Hydro MV wet dispersion accessory after having dispersed each of the positive electrode active materials in a solvent. In order to improve the dispersion of the powder, sufficient ultrasonic irradiation and stirring or flowing compressed air is applied. ), and a surfactant is introduced. The sodium hexametaphosphate (10 %, 3 mL) solution was used as the surfactant and deionized water with ultrasonic irradiation was used as the solvent to disperse each powder sample. D50 is defined as the particle size at 50% of the cumulative volume% distribution.EXAMPLESThe present disclosure is further illustrated in the following (comparative) example(s). Comparative Example 1 (CEX1)

[0052] A cathode active material CEX1 was obtained through following steps:1) Co-precipitation: a transition metal-based oxidized hydroxide precursor with metal composition of Ni0.82Mn0.06Co0.12 was prepared by a co-precipitation process in a large-scale CSTR with mixed nickel-manganese-cobalt sulfates, sodium hydroxide, and ammonia.2) First Mixing: the oxidized hydroxide precursor with metal composition of Ni0.82Mn0.06Co0.12, and LiOH (Li over (Ni + Mn+Co) atomic ratio of 1.03) were mixed homogeneously to prepare a first mixture by using a Henschel mixer.3) First Heating: the first mixture from Step 2) was heated at a first temperature of 550 °C for 5 hours and a second temperature of 805 °C for 8 hours under an oxygen atmosphere followed by and sieving to prepare the first heated material. The sieving was done by using a 270 mesh (according to the US standard mesh size).4) Washing: the first heated material from Step 3) was washed with water with powder to water ratio of 1.0: 0.7 at 15 °C for 5 minutes. The powder was filtered and dried at 140 °C in vacuum and post-treated followed by sieving. The sieving was followed by 270 mesh (according to the US standard mesh size).5) Second Mixing : the washed material obtained from step 4) was homogenously mixed with H3BO3 powder to obtain a second mixture. The second mixture had around 600 ppm of B relative to the total weight of the second mixture.6) Second Heating : The second mixture obtained from step 5) was heated at 310 °C for 8 hours under oxygen atmosphere to obtain a cathode active material powder CEX1.Example 1 (EXI)

[0053] A cathode active material EXI was obtained through following steps:1) Co-precipitation : a transition metal-based oxidized hydroxide precursor with metal composition of Ni0.82Mn0.06Co0.12 was prepared by a co-precipitation process in a large-scale continuous stirred tank reactor with mixed nickel- manganese-cobalt sulfates, sodium hydroxide, and ammonia.2) First Mixing : the oxidized hydroxide precursor with metal composition of Ni0.82Mn0.06Co0.12, LiOH (Li over (Ni + Mn+Co) atomic ratio of 1.03), and Ca(OH)2(Ca over (Ni + Mn+Co) atomic ratio of 0.006) were mixed homogeneously to prepare a first mixture by using a Henschel mixer.3) First Heating : the first mixture from Step 2) was heated at a first temperature of 500°C for 5 hours and a second temperature of 800 °C for 8 hours under an oxygen atmosphere followed by and sieving to prepare the first heated material. The sieving was done by using a 270 mesh (according to the US standard mesh size).4) Washing: the first heated material from Step 3) was washed with water with powder to water ratio of 1 :0.7 at 15 °C for 5 minutes. The powder was filtered and dried at 140 °C in vacuum followed by sieving. The sieving was followed by 270 mesh.5) Second Mixing : The washed material obtained from step 4) was homogenously mixed with H3BO3 powder to obtain a second mixture. The second mixture had around 600 ppm of B relative to the total weight of the second mixture.6) Second Heating : The second mixture obtained from step 5) was heated at 310 °C for 8 hours under oxygen atmosphere to obtain a 2ndheated material.7) Grinding : the 2ndheated material is grinded to achieve a D50 value of 3.0 pm, thereby obtaining the cathode active material powder EXI .

[0054] EXI has a BXPS value of 0.65 as measured by XPS.Comparative Example 2 (CEX2)

[0055] A cathode active material CEX2 was prepared according to the same method as CEX1 except that Step5) and Step 6) were not conducted.

[0056] CEX2 has atomic ratios of Li to (Ni + Mn+Co) of 0.988, Ni to (Ni + Mn+Co) of 0.83, Mn to (Ni + Mn+Co) of 0.05, Co to (Ni + Mn+Co) of 0.12 as measured by ICP-OES analysis.Comparative Example 3 (CEX3)

[0057] A cathode active material CEX3 was prepared according to the same method as EXI except that Step5) and Step 6) were not conducted.Table 3. Properties of cathode active materials**at.% / at.% vs. Ni + Mn+CoTable 5. ICP contents of N i, Mn, and Co*al% vs. Ni + Mn+Co+Ca + B+STable 6. Embodiments according to the disclosure and WO'867

[0058] All examples according to the disclosure relate to CAMs having no Al (i.e., Al-free cathode active materials).

[0059] Presence of S in all EXs and CEXs is from the pCAM that has been synthetized by the CSTR. route.

[0060] CEXl's CAM combines i) removal of Li containing surface impurities by washing and ii) incorporation of boron (B) in its CAM composition for preparing a hNMC CAM. CAM according to CEX1 has a QF value of 17.9%.

[0061] CEX2's CAM is prepared by a same process as CEX1 except skipping the B incorporation. CEX2's CAM has a higher QF than CEX1, meaning that its cycle life is worse than CAM of CEX1. CAM of CEX3 was prepared by a same process as CEX2 except adding a Ca source before the first heating. CAM of CEX3 has a worse cycle life than CAM of CEX2 indicating that the addition of Ca deteriorates the cyclelife. CEX2's CAM has a relatively high specific surface area due to the washing process and skipping B incorporation in its CAM composition.

[0062] EXl's CAM, which is prepared by a same process as CEX1 except adding a Ca source before the first heating, has a better cycle life than CEXl's CAM. It indicates that there is a unexpected synergistic effect among presence of B, Ca, and S in CAM's composition combined with a lower specific surface area for this high Ni cathode active material.

[0063] Figure 1 shows a XRD pattern of EXI as measured by XRD analysis (wherein diffraction peak intensity values are provided in arbitrary unit, i.e. a.u.). It is observed that there is an impurity peak at around 37.3°. The peak is indexed as a Ca oxide-related peak wherein the Ca oxide related peak is associated to CaO.

[0064] EXl's CAM has a BXPS of 0.65. BXPS provides an indication of a degree of CAM's particles surface coverage with B, the highest the BXPS, the more the particles surface is covered with B. Relatively low SSA value of EXl's CAM (BET = 0.610 m2 / g) is correlated with its BXPS value of 0.65. relatively low SSA (at most 0.75 m2 / g) in CAMs according to the disclosure allows to limit occurrence of side reactions between the surface of the CAM secondary particles, thereby impairing microcrack formation and collapse of secondary particles which are primary reasons behind poor cycling performances of a CAM in a battery.

[0065] The low SSA of EXI allows to reduce microcracks formation in CAM secondary particles.

[0066] 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 compound having a formula:LiaNixMnyCOzCacSdQbBwO2, wherein :- 90.00 at% < a < 110.00 at%,75.0 at% < x < 85.0 at%,3.0 at% < y < 6.0 at%, and5.0 at% < z < 14.0 at%0.00 at% < c < 0.75 at%,0.00 at% < w < 0.75 at%,0.040 at% < d < 0.75 at%, or optionally: 0.040 at% < d < 0.55 at%, or optionally: 0.050 at% < d < 0.55 at%, and- 0.00 at% < b < 2.75 at%, with x+y+z+b+c+d+w = 100.00 at% as determined by ICP-OES, wherein Q is at least one element of a list consisting of: Na, Mg, Zr, Nb, W, Si, Ba, Sr, Zn, Cr, V, Y, Sb, Ta, Mo, Ti, wherein the cathode active material powder has a specific surface area of more than 0.50 m2 / g and of at most 0.75 m2 / g as determined by BET analysis, and has a D50 of at least 1.5 pm and of at most 20 pm.

2. The cathode active material powder according to claim 1, wherein the content of Ca is of at least 0.45 at% and of at most 0.65 at% as determined by ICP- OES.

3. The cathode active material powder according to any of the preceding claims, wherein the content of Ca is of at least 0.50 at% and of at most 0.60 at% as determined by ICP-OES.

4. The cathode active material powder according to any of the preceding claims, having a specific surface area of at most 0.65 m2 / g5. The cathode active material powder according to any of the preceding claims, having a Li / M' (at% / at%) ratio of at least 0.90 and at of most 1.10, or of at least 0.95 and of at most 0.99, as determined by ICP-OES.

6. The cathode active material powder according to any of the preceding claims, wherein B is present in a content w of at least 0.55 at% and of at most 0.65at% or of at least 0.60 at% and of at most 0.65 at% as determined by ICP- OES.

7. The cathode active material according to any of the preceding claims, having a specific surface area of at least 0.60 m2 / g or of at most 0.65 m2 / g.

8. The cathode active material powder according to any of the preceding claims, having at least one distinct peak at 20 of at least 37.0° and at most 38.0°, or 20 = 37.5±0.5° wherein a peak intensity ratio of the distinct peak over a (101) peak at 20 = 36.5° is equal to or higher than 0.010 and lower than 0.100, as measured by X-ray diffraction measurement using a Cu-Ko radiation source.

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

10. An electrically powered device including the battery of claim 10.

11. The electrically powered device according to claim 11, selected from the group consisting of: a portable computer, a tablet, a mobile phone, a telecommunication device, a power tool, mobile machinery, a robotic device, an energy storage system, an uninterruptible power supply system, an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an extended- range electric vehicle, a fuel cell electric vehicle, a two-wheeler transportation vehicle, a rail vehicle, a marine vehicle, an aircraft, an aerospace system, a defence device, and a medical device.

12. A process for manufacturing the cathode active material according to any of claims 1 to 8, comprising :- a step of providing a precursor of the cathode active material including Ni, Mn, Co, and S,- a step of providing a Li source, a Ca source, and optionally at least one Q source, the at least one Q source including at least one of the following elements: Na, Mg, Zr, Nb, W, Si, Ba, Sr, Zn, Cr, V, Y, Sb, Ta, Mo, Ti,- a step of mixing the precursor, the Li source, the Ca source, and optionally the at least one Q source together to obtain a first mixture,- a step of subjecting the first mixture to a first heat treatment under an oxidizing atmosphere at a temperature of at least 400°C and at most 900°C for a duration of at least 5 hours to at most 20 hours to obtain a first heated material,- a step of crushing and sieving the first heated material into a crushed material powder,- a step of mixing the crushed material powder with a water-based liquid wherein the weight ratio of water over the crushed material powder is higher than or equal to 20% to obtain a slurry,- a step of removing water from the slurry by filtering and subsequently drying it to obtain a filtered powder,- a step of drying the filtered powder to obtain a dried powder,- a step of mixing the dried powder with a B source to obtain a second mixture, - a step of subjecting the second mixture to a second heat treatment under an oxidizing atmosphere at a temperature of at least 100°C and at most 500°C for a duration of at least 1 hour to at most 10 hours.

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