Lithium nickel-based complex oxides as positive electrode active materials for solid-state lithium-ion rechargeable batteries

Abstract

The present invention relates to a lithium nickel-based composite oxide as a positive electrode active material for lithium-ion rechargeable batteries suitable for electric vehicles and hybrid electric vehicles, the lithium nickel-based composite oxide comprising lithium nickel-based oxide particles containing tungsten.

Description

[0001] TECHNICAL FIELD AND BACKGROUND

[0002] The present invention relates to a lithium nickel-based complex oxide as a positive electrode active material for lithium-ion rechargeable batteries suitable for electric vehicle (EV) and hybrid electric vehicle (HEV) applications, the lithium nickel-based complex oxide comprising lithium nickel-based oxide particles, the lithium nickel-based oxide particles comprising tungsten (W).

[0003] A positive electrode active material is defined as a material that has electrochemical activity in a positive electrode. For an active material, it must be understood that the material is able to capture and release lithium ions when subjected to a voltage change over a predetermined period of time.

[0004] In the framework of the present invention, at% means atomic percentage. at% or "atomic percentage" in the expression of the concentration of a given element means how many percent of all atoms in the compound concerned are atoms of the element in question. Specifying at% is equivalent to specifying mol%.

[0005] The use of W-coated positive electrode materials for solid-state rechargeable batteries was investigated by Lim, C. B. and Park, Y. J. in Sci Rep 10, 10501 (2020).

[0006] However, when applied in solid-state batteries, this positive electrode active material comprising W has a high leakage capacity (Q 总 ).

[0007] It is an object of the present invention to provide a positive electrode active material having an improved Q 总 in solid-state batteries, preferably in solid-state lithium-ion rechargeable batteries obtained by the method of the present invention. SUMMARY

[0008] This object is achieved by providing a positive electrode active material for solid-state batteries, wherein the positive electrode active material comprises Li, M' and oxygen, wherein M' comprises:

[0009] - Ni, the content x of Ni is between 50.0 mol% and 95.0 mol% with respect to M';

[0010] - Co, the content y of Co is between 0.0 mol% and 40.0 mol% with respect to M';

[0011] - Mn, the content z of Mn is between 0.0 mol% and 70.0 mol%, preferably between 0.0 mol% and 40.0 mol% with respect to M';

[0012] - W, the content w of W is between 0.05 mol% and 2.0 mol% with respect to M'

[0013] - Al, the content v of Al being between 0.1 mol% and 3.0 mol%,

[0014] - F, the content f of F being less than 2.0 mol%,

[0015] - Q, the content q of Q being less than 3.0 mol% with respect to the total atomic content of M', wherein Q comprises at least one element of the group consisting of B, Ba, Ca, Cr, Fe, Mg, Mo, Nb, S, Si, Sr, Ti, Y, V and Zr,

[0016] - wherein x, y, z, v, w and q are measured by ICP and wherein f is measured by IC,

[0017] - wherein (x+y+z+v+w+f+q) = 100.0 mol%,

[0018] wherein the ratio Al B / v > 25.0, preferably > 50.0, and W B / w > 5.0, preferably > 10.0,

[0019] wherein Al B and W B are determined by XPS analysis, wherein Al B and W B are expressed as mol% compared to the sum of Ni, Co, Mn, Al, W and F measured by XPS analysis.

[0020] Such material has improved electrochemical properties, in particular a strongly reduced capacity leakage at higher temperatures.

[0021] Preferably, Al B / v > 60.0, more preferably Al B / v > 70.0.

[0022] Preferably, Al B / v < 250.0, more preferably Al B / v < 200.0.

[0023] In certain preferred embodiments, Alb / v is between 60 and 250, preferably between 70 and 200, more preferably between 80 and 135.

[0024] Preferably, W B / w > 21.0, more preferably W B / w > 22.0.

[0025] Preferably, W BW < 150.0, more preferably, W < 100.0. B W < 150.0, more preferably, W < 100.0.

[0026] In certain preferred embodiments, Wb / w is comprised between 21.0 and 150.0, preferably between 22.0 and 100.0, more preferably between 30.0 and 50.0.

[0027] A preferred embodiment is the positive electrode active material of the application wherein the content x of Ni with respect to M' is 55.0 mol% < x < 75.0 mol%, preferably 60.0 mol% < x < 70.0 mol%, more preferably 62.0 mol% < x < 68.0 mol%.

[0028] A preferred embodiment is the positive electrode active material of the application wherein the content x of Ni with respect to M' is 55.0 mol% < x < 75.0 mol%, preferably 60.0 mol% < x < 70.0 mol%, more preferably 62.0 mol% < x < 68.0 mol%.

[0029] As understood by the person skilled in the art, the amount of Li and M', preferably Li, Ni, Mn, Co, W, Al and Q in the positive electrode active material is measured with Inductively Coupled Plasma (ICP). For example, but not limited to the application, Agilent ICP 720-ES is used in the ICP analysis. In the frame of the application, the term "atomic content" or "at%" in the expression of the concentration of a given element means how many percent of all atoms in the compound of interest are atoms of the element in question. The designation mol% is equivalent to "mole percent" or "at%".

[0030] In preferred embodiments, the content z of Mn is 0.0 mol% < z < 40.0 mol%, preferably 3.0 mol% < z < 20.0 mol%, more preferably 5.0 mol% < z < 10.0 mol%.

[0031] In preferred embodiments, the content y of Co with respect to M' is 0.0 mol% < z < 40.0 mol%, preferably 3.0 mol% < z < 20.0 mol%, more preferably 5.0 mol% < z < 10.0 mol%.

[0032] In preferred embodiments, the content w of W with respect to M' is comprised between 0.05 mol% and 2.0 mol%, preferably between 0.1 mol% and 1.0 mol%, more preferably between 0.2 mol% and 0.5 mol% with respect to M'.

[0033] In a preferred embodiment, the content v of Al is between 0.1 and 3.0 mol% with respect to M', preferably between 0.2 and 1.5 mol%, more preferably between 0.3 and 0.5 mol% with respect to M'.

[0034] In a preferred embodiment, the content f of F is less than 2.0 mol% with respect to M', preferably less than 1.5 mol%, more preferably less than 1.2 mol% with respect to M'. In a preferred embodiment, the content f of F is higher than 0.0 mol% with respect to M', preferably higher than 0.5 mol%, more preferably higher than 0.8 mol% with respect to M'. In a certain preferred embodiment, f = 0.0 mol% with respect to M'. As understood by the person skilled in the art, the amount of f is determined with Ion Chromatography (IC) analysis. For example, but not limited to the present application, a Dionex ICS-2100 (Thermo scientific) is used in the IC analysis.

[0035] In a preferred embodiment, the content q of Q is less than 3.0 mol% with respect to the total atomic content of M'. In a preferred embodiment, the content q of Q is less than 2.0 mol% with respect to M', preferably less than 1.0 mol%. In a preferred embodiment, the content q of Q is greater than 0.0 mol% with respect to the total atomic content of M'. In a preferred embodiment, the content q of Q is greater than 0.5 mol% with respect to M', preferably greater than 0.8 mol% with respect to M'. In a certain preferred embodiment, the content q of Q is = 0.0 mol% with respect to M'.

[0036] In a preferred embodiment, f > 0, wherein the ratio F B / f > 10.0, preferably > 12.0, more preferably > 14.0, wherein F B is determined by XPS analysis, wherein F B is expressed as mol% compared to the sum of Ni, Co, Mn, Al, W and F measured by XPS analysis. In a preferred embodiment, f > 0, wherein the ratio F B / f < 30.0, preferably < 20.0, more preferably < 17.0, wherein F B is determined by XPS analysis, wherein F B is expressed as mol% compared to the sum of Ni, Co, Mn, Al, W and F measured by XPS analysis. In a preferred embodiment, f > 0, wherein the ratio F B / f is between 10.0 and 20, preferably between 12.0 and 17.0, more preferably between 14.0 and 16.0, wherein F BIt was determined through XPS analysis, where F B Expressed as mol% compared to the sum of Ni, Co, Mn, Al, W, and F, as measured by XPS analysis.

[0037] In particular, Al B W B and F B These are the average mole fractions of Al, W, and F, respectively, measured in a region of the particles of the cathode material powder according to the invention. This region is defined between a first point at the outer edge of the particles and a second point at a distance from the first point, the distance separating the first and second points being equal to the penetration depth of the XPS, which is included between 1.0 and 10.0 nm. Specifically, the penetration depth is a distance along an axis perpendicular to an imaginary line tangent to the outer edge and passing through the first point.

[0038] In the framework of this invention, the outer edge of a particle is the boundary or external limit that distinguishes the particle from its external environment.

[0039] In a preferred embodiment, the positive electrode active material according to the first aspect comprises secondary particles, which contain more than one primary particle.

[0040] In another preferred embodiment, the positive electrode active material according to the first aspect comprises single crystal particles.

[0041] In some preferred embodiments, if a particle is observed by SEM or TEM, preferably by observing grain boundaries, and the particle consists of only one grain or at most five, preferably at most three, constituent grains, then the particle is considered to be single-crystal.

[0042] In the context of this invention, a grain boundary is defined as the interface between two grains in a particle, preferably wherein the atomic planes of the two grains are aligned with different orientations and meet as a crystallographic discontinuity.

[0043] As will be understood by those skilled in the art and in the context of this invention, the positive electrode active material comprises single-crystal particles, wherein the particles are at least 45 μm × at least 60 μm (i.e., at least 2700 μm) in SEM images. 2 Preferably at least 100μm × 100μm (i.e., at least 10,000μm) 2 In the field of view, 80% or more of the particles are single crystals.

[0044] To identify single-crystal particles, grains with a maximum linear size observed by SEM that is less than 20% of the median grain size D50 determined by laser diffraction are ignored. This avoids particles that are essentially single-crystal but may have several other very small grains deposited on them being mistakenly identified as not being single-crystal.

[0045] In certain preferred embodiments of the invention and in the context of the invention, single-crystal particles are monolithic particles. As those skilled in the art will understand, in these preferred embodiments, all embodiments involving single-crystal particles are equally applicable to monolithic particles.

[0046] In another preferred embodiment, the positive electrode active material according to the first aspect comprises polycrystalline particles. As those skilled in the art will understand, the polycrystalline particles are formed by the aggregation of 5 or more single-crystal particles, preferably 10 or more single-crystal particles, more preferably 50 or more single-crystal particles. This can be observed by observing grain boundaries using suitable microscopy techniques such as scanning electron microscopy (SEM). Aggregation of single-crystal particles to polycrystalline particles occurs during post-processing steps (such as heat treatment).

[0047] In a preferred embodiment, Q comprises at least one element selected from the group consisting of: B, Ba, Ca, Cr, Fe, Mg, Mo, Nb, S, Si, Sr, Ti, Y, V, and Zr. Preferably, Q is at least one element selected from the group consisting of: B, Ba, Ca, Cr, Fe, Mg, Mo, Nb, S, Si, Sr, Ti, Y, V, and Zr. More preferably, it is B, Cr, Nb, S, Si, Ti, Y, and Zr. Most preferably, it is Zr.

[0048] The present invention also relates to a positive electrode for a lithium-ion rechargeable battery comprising a positive electrode active material according to the invention as defined above.

[0049] Preferably, the present invention provides a polymer battery cell for a lithium-ion rechargeable battery, comprising a positive electrode active material according to a first embodiment.

[0050] The present invention also relates to a polymer battery cell for a lithium-ion rechargeable battery, the polymer battery cell comprising a positive electrode active material according to the present invention as defined above.

[0051] The present invention also relates to a lithium-ion rechargeable battery comprising a positive electrode active material according to the invention as defined above.

[0052] The present invention also relates to a method for manufacturing a positive electrode active material for solid-state batteries, the method comprising the following sequential steps:

[0053] -Preparation of lithium transition metal-based oxide compounds

[0054] - The lithium transition metal-based oxide compound is mixed with an Al source and a W source to obtain a mixture, and

[0055] - The mixture is heated in an oxidizing atmosphere in a furnace at a temperature of 250°C to less than 500°C, preferably up to 450°C, for a period of 1 hour to 20 hours in order to obtain the positive electrode active material powder.

[0056] In a preferred embodiment of the method, the lithium transition metal-based oxide compound comprises Li, M' and oxygen, wherein M' comprises Ni, Mn, Co and Q.

[0057] Preferably, the lithium transition metal oxide compound used is also typically prepared according to a lithiation method, i.e., a method in which a mixture of a transition metal precursor and a lithium source is heated at a temperature preferably at least 500°C. Typically, the transition metal precursor is prepared by co-precipitation of one or more transition metal sources (such as salts, and preferably sulfates of elements M', Ni, Mn, and / or Co) in the presence of a basic compound (such as alkali metal hydroxides, for example, sodium hydroxide and / or ammonia).

[0058] Preferably, the lithium transition metal-based oxide compound is mixed with an additional F source to obtain a mixture.

[0059] Preferably, the positive electrode active material is the positive electrode active material according to the present invention as defined above.

[0060] As understood by those skilled in the art, Al B The / v ratio can be increased or decreased, for example, by mixing higher or lower amounts of Al source with lithium transition metal-based oxide compounds.

[0061] As understood by those skilled in the art, W B The / w ratio can be increased or decreased, for example, by mixing higher or lower amounts of W source with lithium transition metal-based oxide compounds.

[0062] As understood by those skilled in the art, F B The / f ratio can be increased or decreased, for example, by mixing higher or lower amounts of the F source with the lithium transition metal-based oxide compound.

[0063] The present invention also relates to a method for manufacturing a polymer battery cell for a solid-state lithium-ion rechargeable battery, wherein the method includes the following steps:

[0064] - The step of preparing a solid polymer electrolyte membrane by mixing a first polyethylene oxide with a molecular weight of less than 1,500,000 g / mol and greater than 500,000 g / mol with a lithium salt in a non-aqueous solvent;

[0065] - The step of preparing a positive electrode by mixing a second polyethylene oxide, a lithium salt, a positive electrode active material and a conductor powder in a non-aqueous solvent, wherein the molecular weight of the second polyethylene oxide is less than 300,000 g / mol and greater than 50,000 g / mol;

[0066] - The steps for preparing a negative electrode containing lithium metal; and

[0067] - The step of assembling a solid polymer electrolyte membrane, a positive electrode, and a negative electrode to form a polymer battery cell for a solid-state rechargeable battery.

[0068] Preferably, the positive electrode active material is the positive electrode active material according to the present invention as defined above.

[0069] The polymer battery cells manufactured according to the present invention are particularly suitable for reliable testing of electrochemical properties. Attached Figure Description

[0070] As further guidance, the accompanying drawings are included to better understand the teachings of the invention. These drawings are intended to aid in describing the invention and are not intended to be limiting of the invention currently disclosed. The drawings and symbols contained herein have the meaning commonly understood by one of ordinary skill in the art to which this invention pertains.

[0071] Figure 1 A scanning electron microscope (SEM) image of a positive electrode active material powder with a polycrystalline morphology according to EX1 is shown.

[0072] Figure 2 SEM images of positive electrode active material powder with single-crystal morphology according to EX2 are shown.

[0073] Figure 3 An X-ray photoelectron spectroscopy (XPS) spectrum is shown, which indicates the presence of Al2p and W4f peaks in EX1 compared to CEX1 and CEX2. Detailed Implementation

[0074] Preferred embodiments are described in detail in the accompanying drawings and the following detailed description to enable practice of the invention. Although the invention has been described with reference to these specific preferred embodiments, the invention includes many alternatives, modifications, and equivalents that will become apparent from the following detailed description and drawings.

[0075] A) Inductively coupled plasma (ICP) analysis

[0076] The amounts of Li, Ni, Mn, Co, Al, B, Ba, Ca, Cr, Fe, Mg, Mo, Nb, S, Si, Sr, Ti, Y, V, W, and Zr in the positive electrode active material powder were measured by inductively coupled plasma (ICP) using an Agilent ICP 720-ES (Agilent Technologies, https: / / www.agilent.com / cs / library / brochures / 5990-6497EN%20720-725_ICP-OES_LR.pdf). Two grams of the powder sample were dissolved in 10 mL of high-purity hydrochloric acid (at least 37% by weight HCl relative to the total weight of the solution) in an Erlenmeyer flask. The flask was covered with a glass slide and heated on a hot plate at 380°C until the precursor was completely dissolved. After cooling to room temperature, the solution in the Erlenmeyer flask was poured into a 250 mL volumetric flask. The volumetric flask was then filled with deionized water to the 250 mL mark and completely homogenized. Take an appropriate amount of solution using a pipette and transfer it to a 250 mL volumetric flask for a second dilution. Fill the flask with internal standard and 10% hydrochloric acid up to the 250 mL mark, then homogenize. Finally, use this 50 mL solution for ICP measurement.

[0077] B) Ion chromatography (IC) analysis

[0078] The amount of F in the positive electrode active material powder was measured using ion chromatography (IC) with a Dionex ICS-2100 (Thermo Scientific). Before use, 250 mL and 100 mL volumetric flasks were rinsed with a 1:1 mixture of 65 wt% HNO3 and deionized water, and then rinsed with deionized water at least five times. A solvent was prepared by mixing 2 mL of HNO3, 2 mL of H2O2, and 2 mL of deionized water. 0.5 g of the powder sample was dissolved in the mixed solvent. The solution was completely transferred from the container to a 250 mL volumetric flask, and the flask was filled to the 250 mL mark with deionized water. The filled flask was shaken thoroughly to ensure homogeneity of the solution. 9 mL of the solution from the 250 mL flask was transferred to a 100 mL volumetric flask. The 100 mL volumetric flask was filled to the 100 mL mark with deionized water, and the diluted solution was shaken thoroughly to obtain a homogeneous sample solution. Insert 2 mL of sample solution into a 5 mL IC vial using a syringe-onguard cartridge for IC measurement.

[0079] C) Scanning electron microscopy (SEM) analysis

[0080] The morphology of the positive electrode active material was analyzed using scanning electron microscopy (SEM). Measurements were performed at 25°C under a high vacuum of 9.6 x 10⁻⁵ Pa using a JEOL JSM7100F (https: / / www.jeolbenelux.com / JEOL-BV-News / jsm-7100f-thermal-field-emission-electron-microscope).

[0081] D) X-ray photoelectron spectroscopy (XPS) analysis

[0082] In this invention, X-ray photoelectron spectroscopy (XPS) is used to analyze the surface of the positive electrode active material powder particles. In XPS measurements, signals are acquired from the first few nanometers (e.g., 1 nm to 10 nm) of the uppermost portion of the sample (i.e., the surface layer). Therefore, all elements measured by XPS are contained within the surface layer.

[0083] For surface analysis of the positive electrode active material powder particles, XPS measurements were performed using a Thermo K-α+ spectrometer (ThermoScientific, https: / / www.thermofisher.com / order / catalog / product / IQLAADGAAFFACVMAHV). Monochromatic Al Kα radiation (hν = 1486.6 eV) was used with a spot size of 400 μm and a measurement angle of 45°. Wide-range measurements were performed at a pass energy of 200 eV to identify elements present on the surface. The C1s peak with maximum intensity (or intermediate intensity) at a binding energy of 284.8 eV was used as the calibration peak position after data collection. Subsequently, at least 10 precise narrow-range scans were performed at 50 eV for each identified element to determine the accurate surface composition.

[0084] Curve fitting was performed using CasaXPS 2.3.19PR1.0 (Casa Software, http: / / www.casaxps.com / ) with Shirley-type background processing and Scofield sensitivity factor. Fitting parameters were based on Table 1a. The line shape GL(30) is a Gaussian / Lorentz product formula with a 70% Gaussian line and a 30% Lorentz line. LA(α,β,m) is an asymmetric line shape, where α and β define the tail extension of the peak, and m defines the width.

[0085] Table 1a. XPS fitting parameters for Ni2p3, Mn2p3, Co2p3, Al2p, W4f and F1s .

[0086]

[0087] For the Al peak within the fitted range of 64.1 ± 0.1 eV to 78.5 ± 0.1 eV, constraints were set for each defined peak according to Table 1b. The Ni3p peak was not included in the quantification.

[0088] Table 1b. XPS fitting constraints for Al2p peak fitting

[0089] Peak Fitting range (eV) FWHM (eV) Area Al2p 72.0-78.5 0.5-3.0 Unconstrained set Ni3p1 68.0-70.5 0.5-2.9 50% of Ni3p3 area Ni3p3 65.3-68.0 0.5-2.9 Unconstrained set Ni3p1 satellite 72.5-75.0 0.5-2.9 20% of Ni3p3 area Ni3p3 satellite 70.5-72.5 0.5-2.9 40% of Ni3p3 area

[0090] The surface contents of Al, W, and F determined by XPS are expressed as the molar percentages of Al, W, and F on the particle surface divided by the total contents of Ni, Mn, Co, Al, W, and F in the surface. They are calculated as follows:

[0091]

[0092]

[0093]

[0094] E) Polymer solid state testing

[0095] E1) Polymer solid state battery preparation

[0096] E1-1) Solid polymer electrolyte (SPE) preparation

[0097] Solid polymer electrolytes (SPEs) are prepared according to the following process:

[0098] Step 1) Using a mixer, mix polyethylene oxide (PEO, 1,000,000 g / mol, Alfa Aesar) with lithium bis(trifluoromethanesulfonyl)imide salt (LiTFSI, >98.0%, TCI) in anhydrous 99.8% wt% acetonitrile (Aldrich) for 30 minutes at 2000 rpm. The mass ratio of polyethylene oxide to LiTFSI is 3.0.

[0099] Step 2) Pour the mixture obtained from Step 1) into a Teflon dish and dry at 25°C for 12 hours.

[0100] Step 3) Separate the dried SPE from the dish and stamp the dried SPE to obtain an SPE disk with a thickness of 300 μm and a diameter of 19 mm.

[0101] E1-2) Positive electrode preparation

[0102] The positive electrode is prepared according to the following process:

[0103] Step 1) Prepare a polymer electrolyte mixture comprising a polyethylene oxide (PEO, 100,000 g / mol, Alfa Aesar) solution in 99.7 wt% (Sigma-Aldrich) anhydrous anisole and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI, >98.0%, TCI) in acetonitrile. The PEO:LiTFSI weight ratio of the mixture is 74:26.

[0104] Step 2) The polymer electrolyte mixture prepared in Step 1), the positive electrode active material, and the conductor powder (Super P, Timcal) are mixed in an acetonitrile solution at a weight ratio of 21:75:4 to prepare a slurry mixture. The mixture is homogenized at 5000 rpm for 45 minutes.

[0105] Step 3) The slurry mixture obtained from Step 2) is cast onto one side of a 20 μm thick aluminum foil, wherein the coating machine slit is 100 μm.

[0106] Step 4) Dry the foil cast from the slurry at 30°C for 12 hours, and then press it to obtain a cathode electrolyte electrode with a diameter of 14 mm.

[0107] E1-3) Negative electrode preparation

[0108] A Li foil (16 mm in diameter and 500 μm in thickness) was prepared as the negative electrode.

[0109] E1-3) Polymer battery cell assembly

[0110] Assemble the button cell polymer battery in an argon-filled glove box in the following order from bottom to top: 2032 button cell casing, positive electrode prepared by section E1-2, SPE prepared by section E1-1, gasket, negative electrode prepared by section E1-3, spacer, wave spring, and battery cap. Then, completely seal the button cell to prevent electrolyte leakage.

[0111] E2) Test methods

[0112] Each coin-type polymer battery cell was cycled at 80°C using a Toscat-3100 computer-controlled constant current cycling station (from Toyo). The coin cell test procedure was performed according to the following schedule, which uses a 1C current definition of 160 mA / g within a metallographic window of 4.4V / Li-3.0V / Li:

[0113] Step 1) Charge in constant current mode with a C rate of 0.05 and a termination condition of 4.4V, then let stand for 10 minutes.

[0114] Step 2) Discharge in constant current mode with a C rate of 0.05 and a termination condition of 3.0V, then let it stand for 10 minutes.

[0115] Step 3) Charge in constant current mode with a C rate of 0.05 and a termination condition of 4.4V.

[0116] Step 4) Switch to constant voltage mode and maintain 4.4V for 60 hours.

[0117] Step 5) Discharge in constant current mode with a C rate of 0.05 and a termination condition of 3.0V.

[0118] Q 总 It is defined as the total leakage capacity under high voltage and high temperature in step 4) according to the test method described above. Q 总 A low value indicates high stability of the positive electrode active material powder during high-temperature operation.

[0119] Example 1

[0120] Polycrystalline positive electrode active material EX1 was prepared according to the following procedure.

[0121] 1) Coprecipitation: Ni metal with a specific composition is prepared by coprecipitation in a large continuous stirred tank reactor (CSTR) containing a mixture of manganese cobalt sulfate, sodium hydroxide, and ammonia. 0.835 Mn 0.080 Co 0.085 A transition metal-based oxidized hydroxide precursor.

[0122] 2) First mixing: The transition metal-based oxidized hydroxide precursor and LiOH as a lithium source are uniformly mixed in an industrial blending device at a lithium to metal M' (Li / M') ratio of 0.98 to obtain a first mixture, wherein M' is the total molar content of Ni, Mn and Co.

[0123] 3) First heating: The first mixture from step 2) was heated at 770°C for 10 hours under an oxygen atmosphere. The heated powder was crushed, graded, and sieved to obtain lithium transition metal composite oxide P1.

[0124] 4) Second mixing: Mix 60 g of P1 with 0.12 g of alumina (Al2O3) nanoparticles and 0.34 g of WO3 to obtain a second mixture.

[0125] 5) Second heating: The second mixture from step 4) is heated at 350°C for 6 hours under an oxygen atmosphere. The heated powder is labeled EX1. This powder contains secondary particles composed of multiple primary particles.

[0126] Example 2

[0127] The single-crystal positive electrode active material EX2 was prepared according to the following procedure.

[0128] 1) Coprecipitation: Ni metal with a specific composition is prepared by coprecipitation in a large continuous stirred tank reactor (CSTR) containing a mixture of manganese cobalt sulfate, sodium hydroxide, and ammonia. 0.850 Mn 0.070 Co 0.080 A transition metal-based oxidized hydroxide precursor.

[0129] 2) First mixing: The transition metal-based oxidized hydroxide precursor and LiOH as the lithium source are uniformly mixed in an industrial blending device at a lithium to metal M' (Li / M') ratio of 0.99 to obtain a first mixture, wherein M' is the total molar content of Ni, Mn and Co.

[0130] 3) First heating: The first mixture from step 2) was heated at 890°C for 11 hours under an oxygen atmosphere. The heated powder was crushed and sieved to obtain lithium transition metal composite oxide P2a.

[0131] 4) Wet milling: 0.50 mol% CoSO4 was added relative to the total amount of Ni, Mn and Co in P2a, and P2a was milled under aqueous conditions. After filtering the solution, the slurry was dried at 175°C for 15 hours in a dry air atmosphere to obtain P2b.

[0132] 5) Second mixing: P2b is uniformly mixed with ZrO2, Co3O4 and LiOH in an industrial blending device to obtain a second mixture, wherein the amounts of ZrO2 and Co3O4 are 0.25 mol% and 0.50 mol% respectively relative to the total amount of Ni, Mn and Co in P2b, and the molar ratio of lithium to metal M' (Li / M') in the second mixture is 0.99, where M' is the total molar content of Ni, Mn and Co in the second mixture.

[0133] 6) Second heating: The second mixture from step 5) was heated at 760°C for 12 hours and 30 minutes under an oxygen atmosphere. The heated powder was crushed and sieved to obtain lithium transition metal composite oxide P2c.

[0134] 7) Third mixing: 60 g of P2c was mixed with 0.12 g of alumina (Al2O3) nanoparticles and 0.34 g of WO3 to obtain the third mixture.

[0135] 8) Third heating: The third mixture from step 7) is heated at 350°C for 6 hours under an oxygen atmosphere. The heated powder is labeled EX2. This powder contains single-crystal particles.

[0136] Example 3

[0137] 60 g of polycrystalline P1 from Example 1 was mixed with 0.12 g of alumina (Al2O3) nanoparticles, 0.34 g of WO3, and 0.18 g of PVDF to obtain a mixture. The mixture was heated at 350 °C for 6 hours in an oxygen-containing atmosphere. The heated powder was labeled EX3.

[0138] Example 4

[0139] 60 g of single-crystal P2c from Example 2 was mixed with 0.12 g of alumina (Al2O3) nanoparticles, 0.34 g of WO3, and 0.18 g of PVDF to obtain a mixture. The mixture was heated at 350 °C for 6 hours in an oxygen-containing atmosphere. The heated powder was labeled EX4.

[0140] Comparative Example 1

[0141] 60 g of P1 from Example 1 was mixed with 0.12 g of alumina (Al2O3) nanoparticles and 0.18 g of PVDF to obtain a mixture. The mixture was heated at 375 °C for 7 hours in an oxygen-containing atmosphere. The heated powder was labeled CEX1.

[0142] Comparative Example 2

[0143] 60 g of P1 from Example 1 was mixed with 0.34 g of WO3 to obtain a mixture. The mixture was heated at 375°C for 7 hours under an oxygen atmosphere. The heated powder was labeled CEX2.

[0144] Table 2 summarizes the chemical composition of the products of the various embodiments and comparative examples, such as Ni, Mn, Co, Al, and W as measured by ICP, and F as measured by IC. Since these products do not contain any other dopants, the compositions in Table 2 are equivalent to the parameters x, y, z, v, w, and f as defined in the claims.

[0145] Table 2.

[0146]

[0147] Table 3 summarizes the chemical composition of the products from the various embodiments and comparative examples, such as Ni, Mn, Co, Al, W, and F as measured by XPS. Since these products contain no other dopants, the composition in Table 3 is equivalent to the parameter Ni as defined in the claims. B Mn B Co B Al B W B and FB .

[0148] Table 3.

[0149]

[0150] Table 4 summarizes the addition amounts of Al2O3, WO3, and PVDF in the examples and comparative examples, the ratio of mole fractions analyzed by XPS and ICP, and the corresponding Q values. 总 EX1, EX2, EX3, and EX4 contain both Al and W, while CEX1 contains Al and F, and CEX2 contains only W. For example... Figure 1 As shown, the positive electrode active material EX1, which contains polycrystalline morphology, was observed by SEM. Figure 2 This is a representative SEM image of EX2, a single-crystal positive electrode active material.

[0151] Table 4. Added amounts of Al2O3, WO3 and PVDF, molar fractions from XPS and ICP analysis for Examples and Comparative Examples Ratios and corresponding Q 总 Summary of Results .

[0152]

[0153] *n / a = Not applicable

[0154] In Table 4, Al(Al) B ), W(W B ) and F(F B The XPS analysis results of Al(v), W(w), and F(f) were compared with the ICP results of Al(v), W(w), and F(f). B W B and F B A value higher than 0 indicates that the Al, W, and F are present on the surface of the positive electrode active material, which is associated with XPS measurements, where the signal is obtained from the first few nanometers (e.g., 1 nm to 10 nm) of the topmost part of the sample (i.e., the surface layer). On the other hand, ICP measurements of v, w, and f originate from the entire particle. Therefore, the ratio of XPS to ICP (such as Al...) B / v、W B / w and F B A / f) value higher than 1 indicates that the elements Al, W, and F are mainly present on the surface of the positive electrode active material. Al B / v、W B / w and F B The higher the / f value, the more Al, W, and F are present on the surface of the positive electrode active material. Al in each embodiment except CEX2 B / v is above 50, W in every embodiment except CEX1 B / w is higher than 20, and F in EX3, EX4 and CEX1 BThe fact that / f is greater than 10 confirms the effectiveness of the Al, W and / or F treatment according to the present invention. Figure 3 The paper presents a representative XPS spectrum of EX1 compared to CEX1 or CEX2, showing the Al2p, W4f5, and W4f7 peaks.

[0155] In some cases, the use of dopants (e.g., one or more of elements B, Ba, Ca, Cr, Fe, Mg, Mo, Nb, S, Si, Sr, Ti, Y, V, or Zr) can be beneficial to battery characteristics. As is well known to those skilled in the art, such materials can be readily introduced by several methods, such as co-precipitation, as in step 1 of Examples 1 and 2; or by adding the desired element source in a mixing step with a Li source, as in step 2 of Examples 1 and 2; and by many other methods known in the art.

Claims

1. A positive electrode active material for a solid-state battery, wherein the positive electrode active material comprises Li, M' and oxygen, wherein M' comprises: -Ni, the Ni content x relative to M' is between 50.0 mol% and 95.0 mol%; -Co, the content of Co y relative to M' is between 0.0 mol% and 40.0 mol%; -Mn, the content of Mn z relative to M' is between 0.0 mol% and 70.0 mol%; -Al, the Al content v is between 0.1 mol% and 3.0 mol%; -W, the content of W is between 0.05 mol% and 2.0 mol%; -F, the content of F is less than 2.0 mol%. - Elements other than Li, O, Ni, Co, Mn, Al, W and F, the content of said elements q is less than 3.0 mol% relative to M' - wherein x, y, z, v, w and q are measured by inductively coupled plasma ICP, and wherein f is measured by ion chromatography IC; -where (x+y+z+v+w+f+q)=100.0mol%; The ratio of the positive electrode active material to Al B / v>25.0 and W B 5.0, Among them Al B and W B It was determined by X-ray photoelectron spectroscopy (XPS) analysis, in which Al B and W B Expressed as mol% of Al and W as measured by X-ray photoelectron spectroscopy (XPS) compared to the sum of Ni, Co, Mn, Al, W, and F.

2. The positive electrode active material according to claim 1, wherein the ratio Al B / v is higher than 50.

0.

3. The positive electrode active material according to claim 1 or claim 2, wherein the content of Mn z relative to M' is between 0.0 mol% and 40.0 mol%.

4. The positive electrode active material according to claim 1 or 2, wherein the ratio Al B / v is below 250.

0.

5. The positive electrode active material according to claim 1 or 2, wherein the ratio W B / w is higher than 10.

0.

6. The positive electrode active material according to claim 1 or 2, wherein the ratio W B / w is below 150.

0.

7. The positive electrode active material according to claim 1 or 2, where f > 0, and the ratio F of the positive electrode active material is... B / f>10.0, where F B It was determined by X-ray photoelectron spectroscopy (XPS) analysis, where F B Expressed as mol% of F as measured by X-ray photoelectron spectroscopy (XPS) analysis compared to the sum of Ni, Co, Mn, Al, W, and F.

8. The positive electrode active material according to claim 1 or 2, wherein the positive electrode active material comprises secondary particles, and the secondary particles comprise more than one primary particle.

9. The positive electrode active material according to claim 1 or 2, wherein the positive electrode active material comprises single crystal particles.

10. A positive electrode for a lithium-ion rechargeable battery, the positive electrode comprising a positive electrode active material according to any one of the preceding claims.

11. A polymer battery cell for a lithium-ion rechargeable battery, the polymer battery cell comprising a positive electrode active material according to any one of claims 1 to 9.

12. A lithium-ion rechargeable battery, the lithium-ion rechargeable battery comprising the positive electrode active material according to any one of claims 1 to 9.

13. A method for manufacturing a positive electrode active material for a solid-state battery, wherein the positive electrode active material is the positive electrode active material according to any one of claims 1 to 9, the method comprising the following sequential steps: -Preparation of lithium transition metal-based oxide compounds - The lithium transition metal-based oxide compound is mixed with an Al source and a W source to obtain a mixture, and - The mixture is heated in an oxidizing atmosphere in a furnace at a temperature of 250°C to less than 500°C for 1 to 20 hours to obtain the positive electrode active material powder.

14. The method of claim 13, wherein the lithium transition metal-based oxide compound is mixed with an Al source, a W source and an additional F source to obtain a mixture.

15. A method for manufacturing a polymer battery cell for a solid-state lithium-ion rechargeable battery, wherein the method comprises the following steps: - The step of preparing a solid polymer electrolyte membrane by mixing a first polyethylene oxide with a molecular weight of less than 1,500,000 g / mol and greater than 500,000 g / mol with a lithium salt in a non-aqueous solvent; - The step of preparing a positive electrode by mixing a second polyethylene oxide, a lithium salt, a positive electrode active material and a conductor powder in a non-aqueous solvent, wherein the second polyethylene oxide has a molecular weight of less than 300,000 g / mol and greater than 50,000 g / mol, and wherein the positive electrode active material is the positive electrode active material according to any one of claims 1 to 9. - The steps for preparing a negative electrode containing lithium metal; and - The step of assembling the solid polymer electrolyte membrane, the positive electrode and the negative electrode to form a polymer battery cell for a solid-state rechargeable battery.

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