Metal oxide products for manufacturing positive electrode active materials for lithium-ion rechargeable batteries

Abstract

1. A metal oxide product for producing a positive electrode active material for a lithium ion rechargeable battery, the metal oxide product comprising one or more oxides of one or more metals M', M' being: Ni with a content x of 20.0 mol % to 100.0 mol % relative to M', Co with a content y of 0.0 mol % to 60.0 mol % relative to M', Mn with a content z of 0.0 mol % to 80.0 mol % relative to M', and D with a content a of 0.0 mol % to 5.0 mol % relative to the total atomic content of M', D being selected from the group consisting of Al, B, Ba, Ca, Cr, Fe, Mg, and D comprising at least one element from the group consisting of Mo, Nb, S, Si, Sr, Ti, Y, V, W, Zn, and Zr, wherein x, y, z, and a are measured by ICP such that x+y+z+a=100.0 mol%, and the metal oxide product comprises secondary particles each comprising a plurality of primary particles, the primary particles having a first particle size distribution determined by analysis of images taken by CS-SEM, the first particle size distribution having a first D50 at most 0.10 μm and a first D99 at most 0.30 μm.

Description

[Technical Field]

[0001] This invention relates to metal oxides applicable to the manufacture of positive electrode active materials for lithium-ion rechargeable batteries. In particular, this invention relates to nickel-based transition metal oxides applicable as precursors for positive electrode active materials. [Background technology]

[0002] In the production of such positive electrode active materials, precursors such as hydroxides, carbonates, or oxides containing the desired transition metal element are usually mixed with a Li source and then subjected to heat treatment to participate in solid-phase reactions, yielding lithiated transition metal oxides.

[0003] A very fine nickel-based transition metal oxide containing primary particles with an average size of 0.4 μm is known from U.S. Patent Application No. 2010196761. However, the properties of the precursor affect the properties of the final cathode active material produced therefrom. For example, the metal oxide containing primary particles from U.S. Patent Application Publication No. 2010196761 has a low primary discharge capacity DQ1 and a large capacity degradation QF. High DQ1 and QF are important for the use of cathode active materials in rechargeable lithium-ion batteries suitable for (hybrid) electric vehicle applications.

[0004] The object of the present invention is to provide a metal oxide for manufacturing a positive electrode active material that can produce a positive electrode active material with improved first discharge capacity and capacity reduction. [Overview of the project] [Means for solving the problem]

[0005] The object of the present invention is a metal oxide product for producing a positive electrode active material for a lithium-ion rechargeable battery, wherein the metal oxide product comprises one or more oxides of one or more metals M', where M' is: Ni with an content of x ranging from 20.0 mol% to 100.0 mol% relative to M', Co with a content of y ranging from 0.0 mol% to 60.0 mol% relative to M', Mn with a content z of 0.0 mol% to 80.0 mol% relative to M', A component D having a content a of 0.0 mol% to 5.0 mol% relative to the total atomic content of M', wherein D contains at least one element from the group consisting of Al, B, Ba, Ca, Cr, Fe, Mg, Mo, Nb, S, Si, Sr, Ti, Y, V, W, Zn, and Zr, and also includes x, y, z, and a were measured by ICP, and x + y + z + a = 100.0 mol%, and the metal oxide product contains secondary particles, each containing multiple primary particles. The primary particles are formed by a metal oxide product having a first particle size distribution, the first particle size distribution having a first D50 of up to 0.10 μm and a first D99 of up to 0.30 μm.

[0006] The first particle size distribution is determined in this case by cross-sectional SEM image analysis. The first particle size distribution is determined as a cumulative particle size distribution. This can be done automatically by image analysis software, but it can also be done manually. To obtain sufficient accuracy, the first particle size distribution is determined for at least 1000 primary particles.

[0007] To calculate the D50 and D99 values ​​of the first particle size distribution, cross-sectional SEM images of transition metal oxide precursor particles contained in the metal oxide product, showing the clear edges of primary particles, should be referenced. Primary particles are selected from the image while avoiding particles that are cut off by the frame. The area enclosed by the edges of individual primary particles is used to calculate the equivalent diameter, which is defined as the diameter of a disk whose area is equal to the area of ​​the particle.

[0008] D50 is defined as the equivalent diameter at the 50% number distribution of the cumulative particle size distribution. Similarly, D99 is defined as the equivalent diameter at the 99% of the cumulative particle size distribution.

[0009] Due to the fact that primary particles are part of larger secondary particles, this oxide product has much better fluidity compared to oxide products having only such primary particles. As a result, the oxide product according to the present invention has low cohesiveness and consequently high bulk density. This has the advantage that the oxide product occupies less space in the process apparatus, particularly in the apparatus for carrying out the heat treatment described above, and consequently the process apparatus has a higher processing capacity.

[0010] Various embodiments of the present invention are disclosed in the claims and specification. The embodiments and examples described in the claims and specification may be freely combined with each other unless expressly specified otherwise. Throughout this specification, where any numerical range is provided, the range includes the endpoint unless expressly specified otherwise.

[0011] In a preferred embodiment, the first D50 is at most 0.10 μm.

[0012] In a preferred embodiment, the first D99 is up to 0.30 μm.

[0013] In a preferred embodiment, the first D50 is at least 0.05 μm, preferably at least 0.06 μm.

[0014] In a preferred embodiment, the first D50 is up to 0.09 μm.

[0015] In a preferred embodiment, the first D99 is at least 0.15 μm, preferably at least 0.17 μm.

[0016] In a preferred embodiment, the first D50 is up to 0.27 μm.

[0017] As described above, the metal element content of the metal oxide product is represented as x, y, z, and a as defined above, and satisfies x + y + z + a = 100.0 mol%. This applies to all embodiments described in this specification.

[0018] In a preferred embodiment, x ≤ 99.0 mol%, for example, 85.0 mol% ≤ x ≤ 99.0 mol%.

[0019] In a preferred embodiment, x ≤ 95.0 mol% and y ≥ 5.0 mol%.

[0020] In a preferred embodiment, 75.0 mol% ≤ x ≤ 85.0 mol%, and 5.0 mol% ≤ y ≤ 15.0 mol%, and more preferably still, 5.0 mol% ≤ z ≤ 15.0 mol%.

[0021] In a preferred embodiment, 50.0 mol% ≤ x ≤ 80.0 mol%, for example, x is 55.0, 60.0, 65.0, 70.0, or 75.0 mol%, and 10.0 mol% ≤ y ≤ 40.0 mol%, for example, y is 15.0, 20.0, 25.0, 30.0, or 35.0 mol%.

[0022] In a preferred embodiment, 20.0 mol% ≤ x ≤ 45.0 mol%, for example, x is 25.0, 30.0, 35.0, or 40.0 mol%.

[0023] In a preferred embodiment, 0.0 mol% ≤ y ≤ 5.0 mol%, for example, y is 1.0, 2.0, 3.0, or 4.0 mol%.

[0024] In a preferred embodiment, 20.0 mol% ≤ x ≤ 25.0 mol%, and 1.0 mol% ≤ y ≤ 3.0 mol%, and more preferably still, 70.0 mol% ≤ z ≤ 80.0 mol%.

[0025] In a preferred embodiment, the one or more oxides of the one or more metals M' constitute at least 80% by weight, preferably at least 90% by weight, of the metal oxide product.

[0026] In a preferred embodiment, the primary particles consist of one or more oxides of the one or more metals M'.

[0027] In a preferred embodiment, x < 100 mol%, and the one or more oxides of the one or more metals M' are mixed metal oxides.

[0028] In this specification, a mixture of single metal oxides is not considered a mixed metal oxide; only oxide compounds containing cations of two or more different metal elements are considered mixed metal oxides.

[0029] Alternatively, a mixed metal oxide can be defined as a metal oxide in which metal elements exist in a mixed state at the atomic level.

[0030] Alternatively, a mixed metal oxide can be defined as a metal oxide in which each particle of the metal oxide contains all of the metal elements present in the metal oxide.

[0031] A mixed salt solution refers to a solution in which salts of different metal elements are present in the same solvent, regardless of whether a specific mixing process took place.

[0032] In a preferred embodiment, the metal oxide product has a second particle size distribution determined by laser diffraction particle size analysis, the second particle size distribution having a second D50, the second D50 being at least 2.0 μm, preferably at least 3.5 μm.

[0033] If this value is respected, it is ensured that the fluidity of the metal oxide product is sufficiently good to obtain a high bulk density.

[0034] In a preferred embodiment, the metal oxide product has a second particle size distribution determined by laser diffraction particle size analysis, the second particle size distribution having a second D50, the second D50 being at most 20 μm, preferably at most 15 μm, and more preferably at most 12.5 μm.

[0035] This ensures sufficiently good lithiation during subsequent heat treatment; otherwise, the long diffusion distance of Li could become a problem.

[0036] For completeness, note that D50 is defined as the equivalent diameter at 50% of the second particle size distribution when expressed as a cumulative volume particle size distribution. Similarly, D99 is defined as the equivalent diameter at 99% of that second particle size distribution.

[0037] In a preferred embodiment, the secondary particles are spherical. This further helps to obtain good fluidity.

[0038] The present invention further relates to a method for producing a positive electrode active material for a lithium-ion rechargeable battery, wherein a metal oxide product according to the present invention is used as a source of one or more metals M' in the positive electrode active material.

[0039] Preferably, in this method, the metal oxide product is mixed with a source of Li, and the mixture is heat-treated at 500°C or higher.

[0040] The present invention further relates to the use of metal oxide products according to the present invention in the production of positive electrode active materials for lithium-ion rechargeable batteries. [Brief explanation of the drawing]

[0041] [Figure 1a] This is a CS-SEM image of Example 1 (EX1). [Figure 1b] This is a CS-SEM image of Comparative Example 1 (CEX1). [Figure 1c] This is a CS-SEM image of Example 4 (EX4). [Figure 1d] This is a CS-SEM image of Example 5 (EX5). [Modes for carrying out the invention]

[0042] The following detailed description includes preferred embodiments to enable the implementation of the present invention. While the present invention is described with reference to these specific preferred embodiments, it will be understood that the present invention is not limited to these preferred embodiments. The present invention includes many alternatives, modifications, and equivalents, which will become apparent from the following detailed description and consideration of the accompanying drawings.

[0043] A) ICP analysis The amounts of metal elements, such as Ni, Mn, and Co, in the precursor, i.e., in the metal oxide product, are measured by inductively coupled plasma (ICP) using the Agilent ICP 720-ES (Agilent Technologies). Two grams of the powder sample are dissolved in 10 mL of high-purity hydrochloric acid (at least 37% by weight of HCl relative to the total weight of the solution) in an Erlenmeyer flask. The flask is covered with a glass and heated on a hot plate at 380°C until the precursor is completely dissolved. After cooling to room temperature, the solution from the Erlenmeyer flask is poured into a 250 mL volumetric flask. The volumetric flask is then filled to the 250 mL mark with deionized water and then homogenized completely. A suitable amount of the solution is pipetteed and transferred to a 250 mL volumetric flask for a second dilution. The volumetric flask is then filled to the 250 mL mark with an internal standard and 10% hydrochloric acid and then homogenized. Finally, this 50 mL solution is used for ICP measurement.

[0044] B) Particle size B1) Secondary particle size analysis The particle size distribution (PSD) of transition metal oxide precursor powders, i.e., metal oxide products, is measured by laser diffraction particle size analysis using a Malvern Mastersizer 3000 equipped with a Hydro MV wet dispersion attachment, after each powder sample is dispersed in an aqueous medium. To improve powder dispersion, sufficient ultrasonic irradiation and stirring are applied, and an appropriate surfactant is introduced. The median diameter, i.e., D50, is defined as the particle size at 50% of the cumulative volume % distribution obtained from the Malvern Mastersizer 3000 by measurement with Hydro MV. Similarly, D99 of this particle size distribution is defined as the equivalent diameter at 99% of this cumulative particle size distribution.

[0045] This particle size distribution is also referred to as the second particle size distribution in this specification.

[0046] B2) Primary particle size analysis The diameter of the primary particles is calculated using MountainsLab® Expert Version 8.0.9286 (Digital Surf) according to the following steps: Step 1) Perform CS-SEM (cross-sectional scanning electron microscope) analysis: The cross-sections of the transition metal oxide precursors described herein are prepared using the ion beam cross-section polishing (CP) instrument JEOL (IB-0920CP). This instrument uses argon gas as the beam source. To prepare the test specimen, a small amount of transition metal oxide precursor powder is mixed with resin and curing agent, and the mixture is then heated on a hot plate for 10 minutes. After heating, it is placed in the ion beam instrument for cutting, and the settings are adjusted to the standard procedure of a voltage of 6.5 kV for a duration of 3 hours. The morphology of the positive electrode active material is analyzed using scanning electron microscopy (SEM) technology. This measurement is performed at 25°C under conditions of 9.6 × 10⁻⁶ -5 This procedure is performed using a JEOL JSM7100F under a high vacuum environment of Pa. Step 2) Load the file containing the cross-sectional SEM image of the transition metal oxide precursor obtained from Step 1) at a magnification of 10,000x. The image should have suitable contrast and brightness so that the edges of the primary particles are clearly visible. Step 3) Set the scale according to the SEM magnification. Step 4) The central area of ​​the secondary particle is extracted by setting the position to 25% to the left and down, and 75% to the right and up. Step 5) In particle analysis, set edge detection, and then set no filter for pretreatment and height pruning < 5%. Step 6) Select Remove for particles on the edge, thereby refining the detection by removing particles that were cut off by the frame line. Step 7) The primary particle diameter is obtained by selecting statistical results and selecting equivalent diameter parameters.

[0047] When particles appear porous in CS-SEM images, pores with an equivalent diameter greater than 0.40 μm are excluded from the measurement, and the mechanical limit at which pores are calculated as particles is determined.

[0048] Here, the cumulative primary particle diameter distribution of primary particles is obtained based on the individual diameters of at least 1000 primary particles from at least one secondary particle.

[0049] This particle size distribution is also referred to as the first particle size distribution in this specification.

[0050] D50 in this particle size distribution is defined as the equivalent diameter at 50% of this cumulative particle size distribution. Similarly, D99 in this particle size distribution is defined as the equivalent diameter at 99% of this cumulative particle size distribution.

[0051] C) Coin cell test C1) Fabrication of coin cells For the preparation of the positive electrode, a slurry containing positive electrode active material powder, conductive agent (Super P, Timcal), and binder (KF#9305, Kureha) in a weight ratio of 90:5:5, along with a solvent (NMP, Mitsubishi), is prepared using a high-speed homogenizer. The homogenized slurry is spread onto one side of an aluminum foil using a doctor blade coater with a gap of 230 μm. The slurry-coated foil is dried in an oven at 120°C and then pressed using a calendering tool. It is then dried again in a vacuum oven to completely remove any residual solvent from the electrode film. The coin cell is assembled in a glove box filled with argon. A separator (Celgard 2320) is placed between the positive electrode and one piece of lithium foil to be used as the negative electrode. 1 M LiPF6 in EC:DMC (1:2) is used as the electrolyte and is dropped between the separator and the electrode. Next, the coin cell is completely sealed to prevent electrolyte leakage.

[0052] C2) Test Method Each coin cell was cycled at 25°C using a Toscat-3100 computer-controlled galvanostatic cycling station (Toyo). The coin cell test schedule used to evaluate the samples is detailed in Table 1. The definition of 1C current is 160 mA / g.

[0053] The first discharge capacity DQ1 is measured in constant current mode (CC). The capacity degradation rate (QF) is calculated using the following formula.

number

[0054] D) Bulk density The bulk density of the precursor material powder, i.e., the metal oxide product, is determined by measuring the mass of the powder flowing into a graduated cylinder of a specific volume. The precursor bulk density is calculated according to the following formula:

number

[0055] The present invention will be further illustrated by the following (non-limiting) embodiments.

[0056] Comparative Example 1 CEX1 was obtained by a spray pyrolysis and spray drying process carried out as follows. 1) Preparation of feed solution: A feed solution was prepared containing NiCl2, MnCl2, and CoCl2 solutions with a total concentration of 110 g / L, having Ni, Mn, and Co in a Ni:Mn:Co ratio of 0.6:0.2:0.2. 2) Spray pyrolysis: The supply solution prepared in step 1) was sprayed into a heating chamber at 650°C to oxidize the salt and form a mixed metal oxide powder. The chamber volume was approximately 8.8 m³. 3 The supply rate was 30 L / hour. 3) Washing: The mixed metal oxide powder from step 2) was washed with water (solid content 25% by weight) to remove impurities such as Cl residue. 4) Slurry composition: A slurry was prepared by mixing the washed powder from step 3) with a dispersant (Dolapix CA, Zschimmer & Schwarz, DE) so that it contained 70% by weight of solids and 2% by weight of dispersant in water. 5) Wet bead milling: The slurry prepared in step 4) was wet-milled in water using a bead mill with a specific grinding energy of 200 kWh / T. The milling medium was Y-stabilized ZrO2 beads (YSZ) with a diameter of 1 mm. The median diameter of the milled powder particles obtained by laser diffraction was 0.71 μm. 6) Spray drying: The milled slurry prepared in step 5) was spray dried using two fluid nozzles with an inlet temperature of 170°C and an outlet temperature of 100°C. 7) Heating: The spray-dried powder obtained from step 6) was heated in an oxygen atmosphere in a 500°C furnace for 5 hours. The result of this step was the heated precursor powder labeled as Comparative Example 1.

[0057] Comparative Example 1 consisted of secondary particles having multiple primary particles. The primary particle size (first particle size distribution) D50, determined according to the method described in the primary particle size analysis, was 0.11 μm, and D99 was 0.35 μm. The secondary particle size (second particle size distribution) D50 was 15.1 μm, and the bulk density was 0.8 gr / cm³. 3 That was the case.

[0058] CEX1 is not based on the present invention.

[0059] Example 1 EX1 was prepared according to the same method as CEX1, except that the wet bead mill specific grinding energy in step 5) was 1300 kWh / T. The median diameter of the milled powder particles in the slurry after step 5, obtained by laser diffraction, was 0.28 μm.

[0060] EX1 consists of secondary particles with multiple primary particles. The primary particle size (first particle size distribution) D50, determined according to the method described in the primary particle size analysis, was 0.08 μm, and D99 was 0.20 μm. The secondary particle size (second particle size distribution) D50 was 12.6 μm, and the bulk density was 1.5 gr / cm³. 3 That was the case.

[0061] Comparative Example 2 CEX2.1 was obtained by a solid-phase reaction between a lithium source and a transition metal precursor, which was carried out as follows. 1) Mixing: The precursor powder CEX1 and LiOH as a lithium source were homogeneously mixed in an industrial blending apparatus at a lithium-to-metallic Me (Li / Me) ratio of 1.05 to obtain a mixture (Me = Ni, Mn, Co). 2) Heating: The mixture from step 1) was heated at 840°C for 15 hours under an oxygen atmosphere. The heated powder was crushed, classified, and sieved to obtain a lithiated product, i.e., cathode active material powder.

[0062] CEX2.2 was prepared according to the same method as CEX2.1, except that the Li / Me ratio in step 1) was 1.03 and the heating temperature in step 2) was 860°C.

[0063] CEX2.1 and CEX2.2 are not based on the present invention.

[0064] Example 2 EX2.1 according to the present invention was prepared according to the same procedure as CEX2.1, except that the precursor powder used in step 1) was EX1 instead of CEX1.

[0065] EX2.2 according to the present invention was prepared according to the same procedure as CEX2.2, except that the precursor powder used in step 1) was EX1 instead of CEX1.

[0066] Example 3 EX3 was prepared according to the same method as EX1, except that the supply solution in step 1) contained only NiCl2. EX3 was 1.5 g / cm³ 3 It is a NiO precursor with a certain bulk density.

[0067] Example 4 EX4 was obtained by a spray pyrolysis and spray drying process carried out as follows. 1) Preparation of feed solution: A feed solution was prepared containing NiCl2, MnCl2, and CoCl2 solutions with a total concentration of 110 g / L, having Ni, Mn, and Co in a Ni:Mn:Co ratio of 0.8:0.1:0.1. 2) Spray pyrolysis: The supply solution prepared in step 1) was sprayed into a heating chamber at 680°C to oxidize the salt and form a mixed metal oxide powder. The chamber volume was approximately 8.8 m³. 3 The supply rate was 30 L / hour. 3) Washing: The mixed metal oxide powder from step 2) was washed with water (solid content 25% by weight) to remove impurities such as Cl residue. 4) Slurry composition: A slurry was prepared by mixing the washed powder from step 3) with a dispersant (Dolapix CA, Zschimmer & Schwarz, DE) so that it contained 60% by weight of solids and 2% by weight of dispersant in water. 5) Wet bead milling: The slurry prepared in step 4) was wet-milled in water using a bead mill with a specific grinding energy of 1500 kWh / T. The milling medium was Y-stabilized ZrO2 beads (YSZ) with a diameter of 0.3 mm. The median diameter of the milled powder particles obtained by laser diffraction was 0.25 μm. 6) Spray drying: The milled slurry prepared in step 5) was spray dried using a rotary sprayer at an inlet temperature of 250°C and an outlet temperature of 100°C. 7) Heating: The spray-dried powder obtained from step 6) was heated in an oxygen atmosphere in a 500°C furnace for 5 hours. The result of this step was a heated precursor powder labeled EX4.

[0068] EX4 consists of secondary particles with multiple primary particles. The primary particle size (first particle size distribution) D50, determined according to the method described in the primary particle size analysis, was 0.05 μm, and D99 was 0.28 μm. The secondary particle size (second particle size distribution) D50 was 12.4 μm, and the bulk density was 1.4 gr / cm³. 3 That was the case.

[0069] Example 5 EX5 was obtained by a spray pyrolysis and spray drying process carried out as follows. 1) Preparation of feed solution: A feed solution was prepared containing NiCl2, MnCl2, and CoCl2 solutions with a total concentration of 110 g / L, having Ni, Mn, and Co in a Ni:Mn:Co ratio of 0.22:0.76:0.02. 2) Spray pyrolysis: The supply solution prepared in step 1) was sprayed into a heating chamber at 600°C to oxidize the salt and form a mixed metal oxide powder. The chamber volume was approximately 8.8 m³. 3and the supply rate was 30 L / h. 3) Washing: The mixed metal oxide powder from Step 2) was washed with water (solid content 25 wt%) to remove impurities such as Cl residues. 4) Slurry formulation: A slurry was prepared by mixing the washed powder from Step 3) with a dispersant (Dolapix CA, Zschimmer & Schwarz, DE) so as to have a solid content of 67 wt% and a dispersant of 2 wt% in water. 5) Wet bead mill: The slurry prepared in Step 4) was wet bead milled in water with a specific grinding energy of 2130 kWh / T. The mill grinding medium was Y-stabilized ZrO2 beads (YSZ) with a diameter of 0.3 mm. The median diameter of the milled powder particles obtained by the laser diffraction method was 0.22 μm. 6) Spray drying: The milled slurry prepared in Step 5) was spray dried with a high-pressure nozzle at an inlet temperature of 250 °C and an outlet temperature of 100 °C. 7) Heating: The spray-dried powder obtained from Step 6) was heated in a furnace at 500 °C for 5 hours in an oxygen atmosphere. The result of this step was the heated precursor powder labeled EX5.

[0070] EX5 was composed of secondary particles having a plurality of primary particles, and the primary particle diameter (first particle size distribution) D50 determined according to the method described in the primary particle diameter analysis was 0.067 μm, and D99 was 0.159 μm. The secondary particle (second particle size distribution) D50 was 7.6 μm, and the bulk density was 0.8 gr / cm 3 was.

Table 2

[0071] Table 2 summarizes the primary particle size distributions of precursors CEX1 and EX1, as well as the preparation conditions and electrochemical properties of CEX2.1, CEX2.2, EX2.1, and EX2.2. The average primary particle size distribution D50 of EX1 is 0.08 μm, which is smaller than the average primary particle size distribution of CEX1, which is 0.11 μm. Primary particle SEM images of EX1 and CEX1 are shown in Figures 1b and 1a, respectively.

[0072] The positive electrode active materials EX2.1 and EX2.2 produced from precursor EX1 exhibit higher DQ1 and lower QF compared to the positive electrode active materials CEX2.1 and CEX2.2 produced from precursor CEX1. A precursor having a first particle size distribution D50 of at least 0.05 μm and a maximum of 0.10 μm and a D99 of at least 0.15 μm and a maximum of 0.30 μm is suitable for achieving the objectives of the present invention and provides a positive electrode active material having an improved first discharge capacity of at least 174 mAh / g and a capacity degradation of up to 17% / 100 cycles.

Claims

1. A metal oxide product for producing a positive electrode active material for a lithium-ion rechargeable battery, wherein the metal oxide product comprises one or more oxides of one or more metals M', and M' is: Ni with an content x of 20.0 mol% to 88.0 mol% relative to M', Co with a content of y ranging from 2.0 mol% to 60.0 mol% relative to M', Mn with a content z of 10.0 mol% to 78.0 mol% relative to M', A D having a content a of 0.0 mol% to 5.0 mol% relative to the total atomic content of M', wherein D contains at least one element from the group consisting of Al, B, Ba, Ca, Cr, Fe, Mg, Mo, Nb, S, Si, Sr, Ti, Y, V, W, Zn, and Zr, and also includes D, x, y, z, and a are measured by ICP and x + y + z + a = 100.0 mol%, and the metal oxide product contains secondary particles each containing a plurality of primary particles. The primary particles have a particle size distribution of primary particles, A metal oxide product having a particle size distribution of primary particles, where D50 consists of primary particles with a size of at least 0.08 μm and a maximum of 0.10 μm, and D99 consists of primary particles with a size of at least 0.08 μm and a maximum of 0.30 μm.

2. The metal oxide product according to claim 1, wherein the D99 of the primary particles is at least 0.15 μm.

3. The metal oxide product according to claim 1, wherein the D50 of the primary particles is at most 0.09 μm.

4. The metal oxide product according to claim 1, wherein the D99 of the primary particles is at least 0.17 μm and at most 0.28 μm.

5. The metal oxide product according to claim 1, wherein x ≤ 85.0 mol% and y ≥ 5.0 mol%.

6. The metal oxide product according to claim 1, wherein 50.0 mol% ≤ x ≤ 80.0 mol% and 10.0 mol% ≤ y ≤ 40.0 mol%.

7. The metal oxide product according to claim 1, wherein the one or more oxides of the one or more metals M' constitute at least 80% by weight of the metal oxide product.

8. The metal oxide product according to claim 1, wherein the primary particles consist of one or more oxides of one or more metals M'.

9. The metal oxide product according to claim 1, wherein x < 100 mol%, and the one or more oxides of the one or more metals M' are mixed metal oxides.

10. The metal oxide product according to claim 1, wherein the metal oxide product has a particle size distribution of secondary particles determined by laser diffraction particle size analysis, the particle size distribution of secondary particles has a D50 of secondary particles, and the D50 of secondary particles is at least 2 μm.

11. The metal oxide product according to claim 1, wherein the metal oxide product has a particle size distribution of secondary particles determined by laser diffraction particle size analysis, the particle size distribution of secondary particles has a D50 of secondary particles, and the D50 of secondary particles is at most 15 μm.

12. The metal oxide product according to claim 1, wherein the secondary particles are spherical.

13. A method for producing a positive electrode active material for a lithium-ion rechargeable battery, wherein a metal oxide product according to any one of claims 1 to 12 is used as a source of one or more metals M'.

14. The method according to claim 13, wherein the metal oxide product is mixed with a source of Li and heat-treated at 500°C or higher.

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