Lithium-nickel composite oxides as cathode active materials for rechargeable solid-state batteries

Abstract

The present invention relates to a cathode active material for a solid-state battery, the cathode active material comprising Li, M', and oxygen, M' comprising Ni with a content x such that 55.0 mol%≦x≦95.0 mol%, Mn with a content y such that 0.0 mol%≦y≦40.0 mol%, Co with a content z such that 0.0 mol%≦z≦40.0 mol%, D with a content a such that 0.0 mol%≦a≦2.0 mol%, D being at least one element other than Li, Ni, Mn, Co, and O, and Zr with a content b such that 0.01 mol%≦b≦5.0 mol%, where x, y, z, a, and b are measured by ICP-OES, and x+y+z+a+b is 100.0 mol%, and the cathode active material comprises a Zr content Zr x and Zr x was determined by XPS analysis, and Zr x is expressed as a mole fraction relative to the sum of the mole fractions of Co, Mn, Ni, and Zr as measured by XPS analysis, the positive electrode active material contains carbon with a content C as measured by a carbon analyzer, C being in weight percent based on the total weight of the positive electrode active material, and Zr x The ratio of Zn to C is 52-0.413 x to 42-0.413 x (wt%). -1 The present invention relates to a positive electrode active material,

Description

[Technical Field]

[0001] The present invention relates to a cathode active material for solid-state rechargeable batteries. More specifically, the present invention relates to a cathode active material containing Zr for solid-state batteries, preferably sulfide-based all-solid-state batteries. The present invention also relates to a method for producing the cathode active material. Furthermore, the present invention relates to a solid-state battery including the cathode active material and the use of the cathode active material in a solid-state battery. [Background technology]

[0002] Lithium nickel-based oxide cathode active materials containing Zr compounds applicable to solid-state batteries are already known, for example, from the literature ACS Appl. Mater. Interfaces 2020, 12, 51, 57146-57154. This literature discloses a cathode active material containing Li, M', and O mixed with Zr ethoxide in an ethanol solvent, where M' is Ni 0.6 Co 0.2 Mn 0.2 This treatment with Zr ethoxide produces a low-efficiency cathode active material when applied to solid-state batteries. Therefore, there is a need to provide a lithium nickel-based oxide cathode active material containing a Zr compound that has improved efficiency in solid-state batteries.

[0003] An object of the present invention is to provide a positive electrode active material containing Zr.

[0004] A further object of the present invention is to provide a method for producing the positive electrode active material.

[0005] A further object of the present invention is to provide a solid-state battery containing the positive electrode active material.

[0006] A further object of the present invention is to provide the use of the cathode active material in a solid-state battery. Summary of the Invention

[0007] The object is to provide a cathode active material for a solid-state battery, the cathode active material comprising Li, M' and oxygen, wherein M' is Ni with a content x of 55.0 mol%≦x≦95.0 mol% relative to M'; Mn with a content y of 0.0 mol%≦y≦40.0 mol%; Co with a content z of 0.0 mol%≦z≦40.0 mol%; D with a content a of 0.0 mol%≦a≦2.0 mol%, where D is at least one element other than Li, Ni, Mn, Co, and O; Zr with a content b of 0.01 mol%≦b≦5.0 mol%, x, y, z, a, and b are measured by ICP-OES; x+y+z+a+b is 100.0 mol%, The positive electrode active material has a Zr content of Zr x and Zr x was determined by XPS analysis, and Zr x is expressed as a mole fraction compared to the sum of the mole fractions of Co, Mn, Ni, and Zr as determined by XPS analysis, the positive electrode active material contains carbon in a content C as measured by a carbon analyzer, C being in wt%; Zr x This is achieved by providing a cathode active material in which the ratio of Cr to C is between 52-0.413·x and 42-0.413·x.

[0008] The present inventors have surprisingly found that by mixing a slurry of a lithium transition metal-based oxide compound, a Zr source in alcohol, and water, followed by filtering the mixture, the resulting active cathode material has a lower ratio of Zr content to carbon content, as compared to active cathode materials conventionally produced by preparing a mixture of a lithium transition metal-based oxide compound and a Zr alkoxide in ethanol, followed by evaporating the ethanol from the mixture, as demonstrated in the accompanying examples. [Brief explanation of the drawings]

[0009] [Figure 1] The graph shows the Ni / M' content (x) of the positive electrode active material in atomic % (x-axis) versus Zr / C (the ratio of Zr / (Ni+Mn+Co+Zr) to the carbon content (wt%) as measured by XPS; y-axis). The patterned areas represent the areas claimed in this invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] In order to enable the practice of the invention, preferred embodiments will be described in detail in the drawings and the following detailed description. While the invention has been described with reference to these specific preferred embodiments, it will be understood that the invention is not limited to these preferred embodiments. On the contrary, the invention encompasses numerous alternatives, modifications and equivalents, as will become apparent from consideration of the following detailed description and the accompanying drawings.

[0011] The term "comprising" as used in the present specification and claims should not be interpreted as being limited to the means listed thereafter, nor does it exclude other elements or steps. It should be interpreted as specifying the presence of the mentioned features, integers, steps, or components as mentioned, but without excluding 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 a composition consisting only of components A and B. It means that, in the context of the present invention, the only relevant components of the composition are A and B. Thus, the terms "comprising" and "including" encompass the more restrictive terms "consisting essentially of" and "consisting of."

[0012] The positive electrode active material is defined as a material that is electrochemically active in the positive electrode, and is understood to be a material that can capture and release Li ions when exposed to a voltage change over a period of time.

[0013] positive electrode active material In a first aspect, the present invention provides a cathode active material for a solid state battery, the cathode active material comprising Li, M′, and oxygen, wherein M′ is Ni with a content x of 55.0 mol%≦x≦95.0 mol%; Mn with a content y of 0.0 mol%≦y≦40.0 mol%; Co with a content z of 0.0 mol%≦z≦40.0 mol%; D with a content a of 0.0 mol%≦a≦2.0 mol%, where D is at least one element other than Li, Ni, Mn, Co, and O; Zr with a content b of 0.01 mol%≦b≦5.0 mol%, x, y, z, a, and b are measured by ICP-OES; x+y+z+a+b is 100.0 mol%, The positive electrode active material has a Zr content of Zr x and Zr x was determined by XPS analysis, and Zr x is expressed as a mole fraction compared to the sum of the mole fractions of Co, Mn, Ni, and Zr as determined by XPS analysis, The positive electrode active material contains carbon in an amount C as measured by a carbon analyzer, where C is in weight percent based on the total weight of the positive electrode active material; Zr x The ratio of C to SiO2 is 52-0.413·x to 42-0.413·x.

[0014] Zr, 52-0.413 x ~ 42-0.413 x x The ratio of C to is shown in Figure 1.

[0015] Preferably, Zr xThe ratio of Zr to C is 50 - 0.413·x to 43 - 0.413·x.

[0016] As will be understood by those skilled in the art, Zr x The unit of the ratio of Zr to C is (wt%). -1 It is.

[0017] In a preferred embodiment, Ni has a content of x ≥ 60.0 mol%, preferably x ≥ 61.0 mol%, more preferably x ≥ 62.0 mol%. In a preferred embodiment, x ≤ 90.0 mol%, preferably x ≤ 88 mol%, more preferably x ≤ 85.0 mol%.

[0018] A more preferred embodiment is the positive electrode active material of the present invention, wherein the content x of Ni 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%.

[0019] A more preferred embodiment is the positive electrode active material of the present invention, wherein the content x of Ni is 75.0 mol% < x ≤ 95.0 mol%, preferably 76.0 mol% ≤ x ≤ 90.0 mol%, more preferably 77.0 mol% ≤ x ≤ 88.0 mol%.

[0020] As will be understood by those skilled in the art, the amounts of Li and M' in the positive electrode active material, preferably Li, Ni, Mn, Co, D and Zr, are measured by Inductively Coupled Plasma - Optical Emission Spectroscopy (ICP - OES). For example, without limiting the present invention, Agilent ICP 720 - ES is used in ICP - OES analysis.

[0021] In a preferred embodiment, Mn has a content of y > 0.0 mol%, more preferably y ≥ 5.0 mol%, still more preferably y ≥ 8.0 mol%. In a preferred embodiment, the content is y ≤ 40.0 mol%, preferably y ≤ 30.0 mol%, more preferably y ≤ 25.0 mol%. In a preferred embodiment, the content is 0.0 mol% < y ≤ 40.0 mol%, preferably 5.0 mol% ≤ y ≤ 8.0 mol%, more preferably 8.0 mol% ≤ y ≤ 25.0 mol%.

[0022] In a preferred embodiment, Co has a content of z > 0.0 mol%, more preferably z ≥ 1.0 mol%, still more preferably z ≥ 3.0 mol%. In a preferred embodiment, the content is z ≤ 40.0 mol%, more preferably z ≤ 30.0 mol%, still more preferably z ≤ 25.0 mol%. In a preferred embodiment, the content is 0.0 mol% < z ≤ 40.0 mol%, preferably 1.0 mol% ≤ z ≤ 30.0 mol%, more preferably 3.0 mol% ≤ z ≤ 25.0 mol%.

[0023] In a preferred embodiment, D is at least one element other than Li, Ni, Mn, Co, Zr, and O.

[0024] In a preferred embodiment, D includes at least one element selected from the group consisting of Al, B, Ba, Ca, Cr, Fe, Mg, Mo, Nb, S, Si, Sr, Ti, Y, V, W, and Zn, preferably at least one element selected from the group consisting of Al, B, Cr, Nb, S, Si, Ti, Y, and W.

[0025] In a highly preferred embodiment, D is at least one element selected from the group consisting of Al, B, Ba, Ca, Cr, Fe, Mg, Mo, Nb, S, Si, Sr, Ti, Y, V, W, and Zn, preferably Al, B, Cr, Nb, S, Si, Ti, Y, and W, more preferably at least one element selected from the group consisting of Al, B, Nb, Ti, and W.

[0026] In a preferred embodiment, D has a content of a > 0.0 mol%, more preferably a ≥ 0.25 mol%, even more preferably a ≥ 0.5 mol%. In a preferred embodiment, the content is a ≤ 2.0 mol%, preferably a ≤ 1.75 mol%, more preferably a ≤ 1.5 mol%. In a preferred embodiment, the content is 0.0 mol% < a ≤ 2.0 mol%, preferably 0.25 mol% ≤ a ≤ 1.75 mol%, more preferably 0.5 mol% ≤ a ≤ 1.5 mol%.

[0027] A preferred embodiment is a positive active material of the present invention in which Zr has a content of b > 0.01 mol%, preferably b ≥ 0.05 mol%, more preferably b ≥ 0.10 mol%. In a preferred embodiment, b ≤ 2.5 mol%, preferably b ≤ 2.0 mol%, more preferably b ≤ 2 mol%. In a preferred embodiment, 0.05 mol% ≤ b ≤ 2.5 mol%, preferably 0.10 mol% ≤ b ≤ 2.0 mol%, more preferably 0.15 mol% ≤ b ≤ 2.0 mol%.

[0028] A specific preferred embodiment is a positive active material of the present invention in which Zr has a content of b > 0.01 mol%, preferably b ≥ 0.05 mol%, more preferably b ≥ 0.10 mol%. In a preferred embodiment, b ≤ 2.5 mol%, preferably b ≤ 2.0 mol%, more preferably b ≤ 1.5 mol%. In a preferred embodiment, 0.05 mol% ≤ b ≤ 2.5 mol%, preferably 0.10 mol% ≤ b ≤ 2.0 mol%, more preferably 0.15 mol% ≤ b ≤ 1.5 mol%.

[0029] In particular, Zr xis the mole fraction of Zr measured in a region of a secondary particle or single-crystal particle of the positive electrode active material according to the present invention, defined between a first point on the outer edge of the particle and a second point at a certain distance from the first point. The distance separating the first point and the second point is equal to the XPS penetration depth, D, which is 1.0 to 10.0 nm. In particular, the penetration depth is the distance along an axis perpendicular to an imaginary line tangent to the outer edge and passing through the first point.

[0030] The outer edge of a particle is, in the framework of the present invention, the boundary or outer limit that distinguishes the particle from its external environment.

[0031] Therefore, XPS analysis provides the atomic content of an element in the top layer of a particle with a penetration depth of about 10.0 nm from the outer boundary of the particle. The outer boundary of a particle is also called the "surface." In the framework of the present invention, atomic % means atomic percentage. Atomic % or "atomic percent" as an expression of the concentration of a given element means what percentage of all atoms in the relevant compound are atoms of that element. The term atomic % is equivalent to mol % or "mole percent." For example, and not limiting to the present invention, XPS analysis is performed using a Thermo K-α+ spectrometer (Thermo Scientific).

[0032] A preferred embodiment is a ratio of Zr x / b>100, preferably with a ratio of Zr x / b>150, more preferably Zr x / b>200. x / b<1000, preferably with a ratio of Zr x / b<500, more preferably Zr x A preferred embodiment is a positive electrode active material in which the ratio Zrx / b is 100 <Zr x / b<1000, preferably 150 <Zr x / b<500, preferably 200 <Zr x / b<350.

[0033] As will be appreciated by those skilled in the art, the defined ratio Zr x The positive electrode active material of the present invention has an enriched amount of Zr in the surface layer of the positive electrode active material. The surface layer of the positive electrode active material is the top 1 to 10 nm of the positive electrode active material. In other words, the positive electrode active material of the present invention includes a coating layer of Zr. In the context of the present invention, the positive electrode active material may include an additional coating layer containing D, where D is at least one element selected from the group consisting of Al, B, Ba, Ca, Cr, Fe, Mg, Mo, Nb, S, Si, Sr, Ti, Y, V, W, and Zn, preferably Al, B, Cr, Nb, S, Si, Ti, Y, and W. The coating layer of Zr may be disposed on the additional coating layer, and / or the additional coating layer may be disposed on the Zr coating layer, and / or the positive electrode active layer may include a mixed coating layer including the coating layer of Zr and the additional coating layer.

[0034] A preferred embodiment of the present invention is a cathode active material in which C≦0.15 wt %, preferably C≦0.12 wt %, and more preferably C≦0.11 wt %, based on the total weight of the cathode active material. A preferred embodiment of the present invention is a cathode active material in which C≧0.01 wt %, preferably C≧0.02 wt %, and more preferably C≧0.03 wt %, based on the total weight of the cathode active material. A preferred embodiment of the present invention is a cathode active material in which C is present in an amount of 0.01 wt % to 0.15 wt %, preferably 0.02 wt % to 0.12 wt %, and more preferably 0.03 wt % to 0.11 wt %, based on the total weight of the cathode active material. As will be understood by those skilled in the art, the carbon content of the cathode active material of the present invention can be measured using a carbon analyzer. For example, without limiting the present invention, the carbon content C can be measured using a Horiba Emia-Expert carbon / sulfur analyzer.

[0035] In a preferred embodiment, the positive electrode active material is 0.15 m 2 / g, preferably greater than 0.25m 2 / g, more preferably 0.45m 2 / g.

[0036] In a preferred embodiment, the positive electrode active material is 2 / g, preferably less than 0.90m 2 / g, more preferably less than 85m 2 In a preferred embodiment, the positive electrode active material has a surface area SA of less than 0.15 m 2 / g~1m 2 / g, preferably 0.25m 2 / g~0.90m 2 / g, more preferably 0.45m 2 / g~0.85m 2 / g。 As will be understood by those skilled in the art, the surface area SA is determined by BET measurement. For example, without limiting the present invention, the surface area can be determined using a Micromeritics Tristar II 3020.

[0037] In a preferred embodiment, the cathode active material of the present invention has a secondary particle median diameter D50 of at least 1.0 μm, preferably at least 2.0 μm, and more preferably at least 3.0 μm. In a preferred embodiment, the cathode active material of the present invention has a secondary particle median diameter D50 of at most 20.0 μm, preferably at most 15.0 μm, and more preferably at most 10.0 μm. In a preferred embodiment, the cathode active material of the present invention has a secondary particle median diameter D50 in an amount of 1.0 μm to 20.0 μm, preferably in an amount of 2.0 μm to 15.0 μm, and more preferably in an amount of 3.0 μm to 10.0 μm. As will be understood by those skilled in the art, the secondary particle median diameter D50 is determined by laser diffraction particle size analysis. For example, and without limitation, the secondary particle median diameter D50 can be determined using a Malvern Mastersizer 3000.

[0038] In a preferred embodiment, the positive electrode active material is a single crystal powder, or, in a more preferred embodiment, the positive electrode active material is a polycrystalline powder.

[0039] The concept of single-crystal powder is well known in the art of cathode active materials. It refers to powders having primarily single-crystal particles. Such powders are a distinct type of powder compared to polycrystalline powders, which are made from primarily polycrystalline particles. Those skilled in the art can easily distinguish between these two types of powders based on microscopic images.

[0040] Single crystal particles are also known in the art as monolithic particles, integral particles or / and monocrystalline particles.

[0041] Although a technical definition of a single crystal powder is not necessary, as one skilled in the art can easily recognize such powders using an SEM, in the context of the present invention, a single crystal powder may be considered to be defined as a powder in which 80% or more of the particles by number are single crystal particles. This means that the powder has a size of at least 45 μm by at least 60 μm (i.e., at least 2700 μm). 2 ), preferably at least 100 μm×100 μm (i.e., at least 10,000 μm 2 ) can be determined on SEM images with a field of view.

[0042] A single crystal particle is a particle that is an individual crystal or is formed from fewer than five, preferably a maximum of three, primary particles that are themselves individual crystals. This can be observed by observing the grain boundaries with a suitable microscopic technique, such as a scanning electron microscope (SEM). Therefore, as will be appreciated by those skilled in the art, the determination of the median secondary particle diameter D50 is also applicable to single crystal powders.

[0043] In determining whether a particle is a single crystal particle, grains having a largest linear dimension observed by SEM that is smaller than 20% of the median diameter D50 of the powder as determined by laser diffraction are ignored. This avoids inadvertently assuming that particles that are essentially single crystal but have some very small other grains, e.g., polycrystalline coatings deposited on them, are not single crystal particles.

[0044] As will be appreciated by those skilled in the art, polycrystalline powders are comprised of secondary particles that include a plurality of primary particles, preferably greater than 20 primary particles, preferably greater than 10 primary particles, and most preferably greater than 5 primary particles.

[0045] As will be appreciated by those skilled in the art, the secondary particles that make up the polycrystalline powders defined herein are polycrystalline particles, and all embodiments relating to secondary particles apply equally to polycrystalline particles as defined herein.

[0046] In a highly preferred embodiment, the cathode active material of the material of the present invention is a single crystal powder having a C to SA ratio greater than 0.01, preferably greater than 0.03, more preferably greater than 0.06. In a highly preferred embodiment, the cathode active material of the material of the present invention is a single crystal powder having a C to SA ratio less than 0.20, preferably less than 0.15, more preferably less than 0.12. In a highly preferred embodiment, the cathode active material of the material of the present invention is a single crystal powder having a C to SA ratio in the range of 0.01 to 0.20, preferably in the range of 0.03 to 0.15, more preferably in the range of 0.06 to 0.12.

[0047] Certain highly preferred cathode active materials of the present invention are single-crystal powders having a primary particle median D50 value of less than 10.0 μm, preferably less than 8.0 μm, and more preferably less than 7.0 μm. In certain preferred embodiments, the cathode active materials of the present invention are single-crystal powders having a primary particle median D50 value of greater than 1.0 μm, preferably greater than 2.0 μm, and more preferably greater than 3.0 μm. In certain preferred embodiments, the cathode active materials of the present invention are single-crystal powders having a primary particle median D50 value of 1.0 μm to 10.0 μm, preferably 2.0 μm to 8.0 μm, and more preferably 3.0 μm to 5.0 μm. As will be appreciated by those skilled in the art, the particle size distribution (PSD) D50 of cathode active material powders is measured by laser diffraction particle size analysis. For example, and not by way of limitation, particle median D50 can be measured using a Malvern Mastersizer 3000.

[0048] In a highly preferred embodiment, the cathode active material of the present invention is a polycrystalline powder having a C to SA ratio greater than 0.10, preferably greater than 0.12, more preferably greater than 0.15. In a highly preferred embodiment, the cathode active material of the present invention is a polycrystalline powder having a C to SA ratio less than 0.25, preferably less than 0.22, more preferably less than 0.20. In a highly preferred embodiment, the cathode active material of the present invention is a polycrystalline powder having a C to SA ratio in the range of 0.10 to 0.25, preferably in the range of 0.12 to 0.22, more preferably in the range of 0.15 to 0.20.

[0049] Certain highly preferred cathode active materials of the present invention are polycrystalline powders having a median secondary particle size D50 of at least 1.0 μm, preferably at least 2.0 μm, and more preferably at least 3.0 μm. In certain highly preferred embodiments, the cathode active materials of the present invention are polycrystalline powders having a median secondary particle size D50 of at most 20.0 μm, preferably at most 15.0 μm, and more preferably at most 10.0 μm. In preferred embodiments, the cathode active materials of the present invention are polycrystalline powders having a median secondary particle size D50 in the range of 1.0 μm to 20.0 μm, preferably in the range of 2.0 μm to 15.0 μm, and more preferably in the range of 3.0 μm to 10.0 μm. As will be appreciated by those skilled in the art, the median secondary particle size D50 can be determined by laser diffraction particle size analysis. For example, and not by way of limitation, the median secondary particle size D50 can be determined using a Malvern Mastersizer 3000.

[0050] As will be appreciated by those skilled in the art, the ratio of C to SA is expressed in units of weight percent (g / m 2 )

[0051] In a second aspect, the present invention provides a cathode active material for a solid-state battery, the cathode active material comprising Li, M′, and oxygen, wherein M′ is: Ni with a content x of 55.0 mol%≦x≦75.0 mol%, preferably 60.0 mol%≦x≦70.0 mol%, more preferably 62.0 mol%≦x≦68.0 mol%, Mn with a content y of 0.0 mol%≦y≦40.0 mol%; Co with a content z of 0.0 mol%≦z≦40.0 mol%; D with a content a of 0.0 mol%≦a≦2.0 mol%, where D is at least one element other than Li, Ni, Mn, Co, and O; Zr with a content b of 0.01 mol%≦b≦5.0 mol%, x, y, z, a, and b are measured by ICP-OES; x+y+z+a+b is 100.0 mol%, The positive electrode active material has a Zr content of Zr x and Zr x is determined by XPS analysis, and Zr x is expressed as a molar fraction compared to the total molar fractions of Co, Mn, Ni, and Zr determined by XPS analysis, The positive electrode active material contains carbon with a content C measured by a carbon analyzer, and C is in units of weight%, Zr x The ratio of Zr -1 to C is 10 to 30 (weight%), -1 preferably 15 to 25 (weight%), -1 more preferably 18 to 22 (weight%).

[0052] A very preferred embodiment is the positive electrode active material of the present invention in which D is at least one element other than Li, Ni, Mn, Co, Zr, and O.

[0053] As will be understood by those skilled in the art, all embodiments related to the positive electrode active material according to the first aspect are applied by making the necessary changes to the positive electrode active material according to the second aspect.

[0054] In a third aspect, the present invention is a positive electrode active material for a solid battery, wherein the positive electrode active material contains Li, M' and oxygen, and M' is Ni with a content x of 75.0 mol% < x ≤ 95.0 mol%, preferably 76.0 mol% ≤ x ≤ 90.0 mol%, more preferably 77.0 mol% ≤ x ≤ 88.0 mol%, Mn with a content y of 0.0 mol% ≤ y ≤ 40.0 mol%, Co with a content z of 0.0 mol% ≤ z ≤ 40.0 mol%, D with a content a of 0.0 mol% ≤ a ≤ 2.0 mol%, where D is at least one element other than Li, Ni, Mn, Co, and O, and Zr with a content b of 0.01 mol% ≤ b ≤ 5.0 mol%, where x, y, z, a, and b are measured by ICP - OES, x+y+z+a+b is 100.0 mol%, The positive electrode active material has a Zr content of Zr x and Zr x was determined by XPS analysis, and Zr x is expressed as a mole fraction relative to the sum of the mole fractions of Co, Mn, Ni, and Zr as determined by XPS analysis; the positive electrode active material contains carbon with a content C as measured by a carbon analyzer, where C is in wt.%; Zr x The ratio of C to SiO2 is 7 to 30 (wt%). -1 , preferably 8 to 25 (wt%) -1 , more preferably 9 to 20 (wt%) -1 The present invention relates to a positive electrode active material,

[0055] A highly preferred embodiment is a cathode active material of the present invention in which D is at least one element other than Li, Ni, Mn, Co, Zr, and O.

[0056] As will be appreciated by those skilled in the art, all embodiments relating to the active cathode material according to the first aspect apply mutatis mutandis to the active cathode material according to the third aspect.

[0057] Manufacturing method In a fourth aspect, the present invention also provides a method for producing a positive electrode active material, comprising: preparing a slurry of a lithium transition metal-based oxide compound, Li, water, and alcohol; mixing the slurry with a Zr source to obtain a mixture; and heating the mixture at a temperature between 250° C. and 500° C. in an oxidizing atmosphere for a time between 1 hour and 20 hours.

[0058] A highly preferred embodiment is a method for making an active cathode material, wherein the active cathode material is according to the first aspect of the invention, according to the second aspect of the invention, and / or according to the third aspect of the invention.

[0059] 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 D, wherein D is Al, B, Ba, Ca, Cr, Fe, Mg, Mo, Nb, S, Si, Sr, Ti, Y, V, W and Zn; preferably at least one element from the group consisting of Al, B, Cr, Nb, S, Si, Ti, Y, W.

[0060] Preferably, the lithium transition metal oxide powders used are also typically prepared according to a lithiation process, i.e., a process in which a mixture of a transition metal precursor and a lithium source is heated, preferably at a temperature of at least 500° C. Typically, the transition metal precursor is prepared by co-precipitation of one or more transition metal sources, such as salts, preferably sulfates, of the M′ elements Ni, Mn and / or Co, in the presence of an alkali compound, such as an alkali hydroxide, for example sodium hydroxide and / or ammonia.

[0061] Preferably, the method comprises the further step of filtering and drying the mixture before heating it, preferably under vacuum or a constant flow of N2 gas for at least 4 hours and at most 20 hours.

[0062] In a preferred embodiment of the present method, the Zr source is a Zr alkoxide, preferably Zr ethoxide, Zr propoxide, or Zr butoxide, more preferably Zr propoxide. In a preferred embodiment, the Zr alkoxide is mixed with the mixture as a solid. Alternatively, more preferably, the Zr alkoxide is mixed with the slurry as a solution, the solution comprising the Zr alkoxide and an additional alcohol, the alkoxide group being the conjugate base of the additional alcohol. For example, the Zr alkoxide is Zr propoxide dissolved in propanol. Typically, the solution contains 50 to 90 wt. % of the Zr alkoxide based on the total weight of the solution. Examples of such solutions are 70 wt. % Zr propoxide in 1-propanol or 80 wt. % Zr butoxide in 1-butanol.

[0063] Preferably, the alcohol solvent is methanol, ethanol, propanol or butanol, preferably ethanol.

[0064] In a preferred embodiment, the amount of water in the slurry is 0.5 mol% to 25.0 mol%, preferably 0.7 mol% to 10.0 mol%, more preferably 1 mol% to 5 mol%, based on the metal content in the lithium transition metal oxide compound. In a preferred embodiment, the molar ratio of water to Zr alkoxide in the slurry is at least 2:1, preferably at least 3:1, more preferably at least 4:1. In a preferred embodiment, the molar ratio of water to Zr alkoxide in the slurry is at most 10:1, preferably at most 8:1, more preferably at most 6:1. In a preferred embodiment, the molar ratio of water to Zr alkoxide in the slurry is 2:1 to 10:1, preferably 3:1 to 8:1, more preferably 4:1 to 6:1.

[0065] A preferred embodiment of the method is to heat the mixture at a temperature of 275°C to 450°C, preferably 300 to 400°C, more preferably 325 to 375°C.

[0066] A preferred embodiment of the method is to heat the mixture, and the oxidizing atmosphere comprises or consists of oxygen, such as air.

[0067] Product by Process In a fifth aspect, the present invention relates to a positive electrode active material obtainable by the method according to the fourth aspect of the present invention.

[0068] As will be appreciated by those skilled in the art, all embodiments relating to the positive electrode active material according to the first aspect of the invention, the second aspect of the invention, the third aspect of the invention, and / or the method according to the fourth aspect of the invention apply mutatis mutandis to the positive electrode active material obtainable by the method according to the invention. For example, the Li, M', Zr content Zr described herein in the context of the positive electrode active material may be used.x The various embodiments regarding the identity and amount of the carbon content C are equally applicable to the positive electrode active material obtainable by the method for preparing the positive electrode active material.

[0069] battery In a sixth aspect, the present invention relates to a battery comprising an active cathode material according to the first aspect of the invention, the second aspect of the invention, and / or the third aspect of the invention.

[0070] In a preferred embodiment, the battery is a solid-state battery. Preferably, the solid-state battery comprises a sulfide-based electrolyte. Preferably, the electrolyte is a sulfide-based solid electrolyte, more preferably, the electrolyte comprises Li, P, and S. In a highly preferred embodiment, the battery is a sulfide solid-state battery.

[0071] In a preferred embodiment, the battery according to the present invention has an efficiency of at least 88%, preferably at least 90%, more preferably at least 92%, and most preferably at least 94%. As will be appreciated by those skilled in the art, the efficiency of a battery is determined as described under section D) of the Examples.

[0072] use In a seventh aspect, the present invention relates to the use of an active cathode material according to the first aspect of the invention, the second aspect of the invention, and / or the third aspect of the invention in a battery.

[0073] A preferred embodiment is the use of the cathode active material in a battery, preferably a solid-state battery, more preferably a sulfide solid-state battery, to increase the efficiency of the battery.

[0074] In an eighth aspect, the present invention relates to the use of a battery according to the present invention in any one of a portable computer, a tablet, a mobile phone, an energy storage system, an electric vehicle or a hybrid electric vehicle, preferably in an electric vehicle or a hybrid electric vehicle. [Example]

[0075] A) ICP analysis The amounts of Li, Ni, Mn, Co, and Zr in the positive electrode active material powder were measured by inductively coupled plasma (ICP-OES) using an Agilent ICP 720-ES. Two grams of powder sample was dissolved in 10 mL of high-purity hydrochloric acid (at least 37 wt.% HCl based on the total weight of the solution) in an Erlenmeyer flask. The flask was covered with glass and heated on a hot plate at 380 °C until the powder 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 to the 250 mL mark with deionized water and then thoroughly homogenized. An appropriate amount of the solution was removed with a pipette and transferred to a 250 mL volumetric flask for the second dilution. The volumetric flask was then filled to the 250 mL mark with an internal standard and 10% hydrochloric acid, followed by homogenization. Finally, this 50 mL solution was used for ICP-OES measurement.

[0076] B) Particle size The particle size distribution (PSD) of the positive electrode active material powders was measured by laser diffraction particle size analysis using a Malvern Mastersizer 3000 equipped with a Hydro MV wet dispersion accessory after dispersing each powder sample in an aqueous medium. Sufficient ultrasonic irradiation and stirring were applied to improve the dispersion of the powder, and a suitable surfactant was introduced. D50 was defined as the particle size at 50% of the cumulative volume percent distribution obtained from the Malvern Mastersizer 3000 using Hydro MV measurements.

[0077] C) X-ray photoelectron spectroscopy In the present invention, X-ray photoelectron spectroscopy (XPS) is used to analyze the surface of positive electrode active material powder particles. In XPS measurements, signals are obtained from the top of the sample, i.e., the first few nanometers (e.g., 1 nm to 10 nm) of the surface layer. Therefore, all elements measured by XPS are contained in the surface layer.

[0078] For surface analysis of the positive electrode active material powder particles, XPS measurements were performed using a Thermo K-α+ spectrometer (Thermo Scientific). Monochromated Al Kα radiation (hυ = 1486.6 eV) was used with a spot size of 400 μm and a measurement angle of 45°. A broad survey scan to identify the elements present on the surface was performed with a pass energy of 200 eV. The C1s peak with maximum intensity (or center) at a binding energy of 284.8 eV was used as the calibration peak position after data collection. Then, for each identified element, at least 10 precise narrow scans at 50 eV were performed to determine the exact surface composition.

[0079] Curve fitting was performed with CasaXPS version 2.3.19PR1.0 (Casa Software) using Shirley-type background processing and Scofield sensitivity coefficients. Fitting parameters are given in Table 1a. The line shape GL(30) is the Gaussian / Lorentzian product formula for the 70% Gaussian and 30% Lorentzian lines.

[0080] [Table 1]

[0081] For Zr and Co peaks, limits are set for each specified peak according to Table 1b.

[0082] [Table 2]

[0083] The surface content of Zr determined by XPS is expressed as the mole fraction of Zr in the surface layer of a particle divided by the total content of Ni, Mn, Co and Zr in that surface layer, which is calculated as follows:

[0084]

number

[0085] D) Sulfide solid-state battery testing D1) Preparation of sulfide solid-state batteries Preparation of the positive electrode: To prepare the positive electrode, a slurry containing the positive electrode active material powder, Li-PS solid electrolyte, carbon (Super-P, Timcal), and binder (RC-10, Arkema) in a weight ratio of 64.0:30.0:3.0:3.0 in butyl acetate solvent was mixed in an Ar-filled glove box. The slurry was cast onto one side of aluminum foil, and the coated foil was then dried in a vacuum oven to obtain the positive electrode. The resulting positive electrode was punched out to a diameter of 10 nm, with an active material loading of approximately 4 mg / cm. 2 is.

[0086] Preparation of the negative electrode: To prepare the negative electrode, a Li foil (3 mm diameter, 100 μm thickness) is placed centered on an In foil (10 nm diameter, 100 μm thickness) and pressed to form a Li-In alloy negative electrode.

[0087] Separator For the preparation of a separator that also functions as a solid electrolyte in a battery, the Li-PS-based solid electrolyte is pelletized under a pressure of 250 MPa to obtain a pellet thickness of 100 μm.

[0088] Cell assembly The sulfide solid-state battery was assembled in an argon-filled glove box from bottom to top: cathode with Al current collector with a coated portion on top, separator, anode with Li side up, and Cu current collector. The stacked components were pressed together at a pressure of 250 MPa and placed in an external cage to prevent air exposure.

[0089] D2) Test method The test method is a conventional "constant cut-off voltage" test. Conventional cell testing in this invention follows the schedule shown in Table 2. Each cell is cycled at 60°C using a Toscat-3100 computer-controlled galvanostatic cycling station (manufactured by Toyo).

[0090] This schedule uses a 1C current definition of 160mA / g. The initial charge capacity (CQ1) and discharge capacity (DQ1) are measured from 4.3V to 2.5V (Li / Li + ) or 3.7V~1.9V(InLi / Li + ) voltage range, at a C rate of 0.1C, in constant current mode (CC).

[0091] The efficiency EF is expressed as a percentage as follows:

[0092]

number

[0093] [Table 3]

[0094] E) Carbon analyzer The carbon content of the cathode active material powder is measured using a Horiba Emia-Expert carbon / sulfur analyzer. 1 g of cathode active material powder is placed in a ceramic crucible in a high-frequency induction furnace. 1.5 g of tungsten and 0.3 g of tin as promoters are added to the crucible. The powder is heated at a programmable temperature where the gases produced during combustion are analyzed by an infrared detector. The carbon concentration is determined by CO2 and CO2 analysis.

[0095] F) Surface area analysis The specific surface area of ​​the positive electrode active material is measured by the Brunauer-Emmett-Teller (BET) method using a Micromeritics Tristar II 3020. To remove adsorbed species, the powder sample is heated at 300 °C for 1 hour before measurement under nitrogen (N2) gas. The dried powder is placed in a sample tube. The sample is then degassed at 30 °C for 10 minutes. The nitrogen adsorption test is performed at 77 K with this device. The nitrogen adsorption / desorption isotherm is obtained to determine the m 2 The total specific surface area of ​​the sample in units of / g is derived.

[0096] The invention is further illustrated by the following (non-limiting) examples.

[0097] Comparative Example 1 A single crystalline positive electrode active material labeled CEX (Comparative Example) 1 was prepared according to the following steps. Step 1) Preparation of transition metal oxide hydroxide precursor: Metal composition Ni 0.8 Mn 0.1 Co 0.1 A nickel-based transition metal oxide hydroxide powder (TMH1) with ##STR10## was prepared by a co-precipitation process in a large-scale continuous stirred tank reactor (CSTR) containing mixed nickel manganese cobalt sulfate, sodium hydroxide, and ammonia. Step 2) Oxidation of precursor: TMH1 prepared in step 1) was heated at 400°C for 7 hours in an oxidizing atmosphere to obtain a heated product. Step 3) First Mixing: The transition metal-based oxide hydroxide precursor and LiOH as the lithium source were homogeneously mixed in an industrial blending device at a lithium to metal M′ (Li / M′) ratio of 1.02 to obtain a first mixture. Step 4) First heating: The first mixture from step 3) was heated at 730°C for 10 hours under an oxygen atmosphere. The heated product was crushed, classified and sieved to obtain a first heated product. Step 5) Second heating: The first heating product from step 4) was heated at 920° C. for 10 hours under an oxygen atmosphere to obtain a second heating product. Step 6) Wet bead milling: The second-heated product from step 5) was bead milled in a solution containing 0.5 mol% Co relative to the total molar content of Ni, Mn, and Co in the second-heated product, followed by drying and sieving to obtain a milled product. The weight ratio of solid to solution for bead milling was 1:1, and the bead milling was carried out for 20 minutes. Step 7) Second Mixing: The milled product obtained from step 6) was mixed in an industrial blender with 1.5 mol % Co from CO3O4 and 4 mol % Li from LiOH, each relative to the total molar content of Ni, Mn, and Co in the milled product, to obtain a second mixture. Step 8) Third heating: The second mixture from step 7) was heated at 760°C for 10 hours under an oxidizing atmosphere, followed by grinding and sieving with the addition of 250 ppm alumina powder to obtain an intermediate product. Step 9) Wet mixing: Zr was introduced into the positive electrode active material by applying the following steps 9a) to 9c). Step 9a) Preparation of Zr solution: 0.8 mol% Zr from Zr propoxide (70 wt% Zr propoxide in n-propanol solution), 1.6 mol% Li from Li ethoxide powder, and ethanol solvent were mixed to form a solution, based on the total molar contents of Ni, Mn, and Co in the intermediate product, respectively. The amount of ethanol solvent was 55 wt% of the total weight of the designated intermediate product to be mixed in Step 9b). Step 9b) Mixing: The intermediate product obtained from step 8) was mixed with the Zr solution prepared in step 9a) in a heatable reactor for 20 minutes. Step 9c) Heating: Heat of 70°C was applied to the reactor of step 9b) while the reactor was connected to a vacuum pump to evaporate the volatile phase. A dry powder was obtained from this step. Step 10) Fourth Heating: The dried powder from step 9c) was heated at 350°C for 6 hours under oxygen atmosphere to obtain CEX1 with M' containing Ni, Mn, Co, and Zr, with a Ni:Mn:Co:Zr ratio of 0.79:0.10:0.11:0.007 as determined by ICP-OES. CEX1 has a D50 of 4 μm.

[0098] Example 1 A single crystalline positive electrode active material labeled EX (Example) 1 was prepared according to the following steps. Step 1) Preparation of Zr solution: 0.8 mol% Zr from Zr propoxide (70 wt% Zr-propoxide in n-propanol solution) was dissolved in 3 grams of ethanol. Step 2) Slurry preparation: 70 grams of the intermediate product obtained from step 8) in the preparation of CEX1 was mixed with 1.6 mol % LiOH and 4 mol % water, both relative to M', and 26 grams of ethanol to form a slurry. Step 3) Mixing: The Zr solution prepared from step 1) and the slurry prepared from step 2) were mixed and stirred at room temperature for 15 hours, followed by filtration and drying in vacuum at 80°C for 6 hours. Step 4) Heating: The dried powder from step 3) was heated at 350°C for 6 hours under oxygen atmosphere to obtain EX1 with M' containing Ni, Mn, Co, and Zr, with a Ni:Mn:Co:Zr ratio of 0.79:0.10:0.11:0.007 as determined by ICP-OES. EX1 has a D50 of 4 μm.

[0099] Comparative Example 2 A single-crystalline positive electrode active material, labeled CEX2, was prepared according to the following steps. Step 1) Preparation of transition metal oxide hydroxide precursor: Metal composition Ni 0.85 Mn 0.07 Co 0.08 Nickel-based transition metal oxide hydroxide powder (TMH2) with SiO2 was prepared by a co-precipitation process in a large-scale continuous stirred tank reactor (CSTR) containing mixed nickel manganese cobalt sulfate, sodium hydroxide, and ammonia. Step 2) Oxidation of the precursor: The TMH2 prepared in step 1) was heated at 400°C for 7 hours in an oxidizing atmosphere to obtain a heated product. Step 3) First Mixing: The heated product prepared in step 2) was mixed with LiOH in an industrial blender to obtain a first mixture with a lithium to metal M' (Li / M') ratio of 0.96. Step 4) First heating: The first mixture from step 3) was heated at 890° C. for 11 hours under an oxidizing atmosphere to obtain a first heating product. Step 5) Wet bead milling: The first-heated product from step 4) was bead milled in a solution containing 0.5 mol% Co relative to the total molar content of Ni, Mn, and Co in the first-heated product, followed by drying and sieving to obtain a milled product. The weight ratio of solid to solution for bead milling was 6:4, and the bead milling was carried out for 20 minutes. Step 6) Second Mixing: The milled product obtained from step 5) was mixed in an industrial blender with 1.5 mol % Co from CO3O4 and 7.5 mol % Li from LiOH, each relative to the total molar content of Ni, Mn, and Co in the milled product, to obtain a second mixture. Step 7) Second heating: The second mixture from step 6) was heated at 760°C for 10 hours under an oxidizing atmosphere, followed by grinding and sieving with the addition of 250 ppm alumina powder to obtain an intermediate product. Step 8) Wet mixing: Zr was introduced into the positive electrode active material by applying the following steps 8a) to 8c). Step 8a) Preparation of Zr solution: 0.75 mol% Zr from Zr propoxide (70 wt% Zr propoxide in n-propanol solution), 1.5 mol% Li from Li ethoxide powder, and ethanol solvent were mixed to form a solution, based on the total molar contents of Ni, Mn, and Co in the intermediate product, respectively. The amount of ethanol solvent was 55 wt% of the total weight of the designated intermediate product to be mixed in Step 8b). Step 8b) Mixing: The intermediate product obtained from step 7) was mixed with the Zr solution prepared in step 7a) in a heatable reactor for 20 minutes. Step 8c) Heating: Heat of 70°C was applied to the reactor of step 8b) while the reactor was connected to a vacuum pump to evaporate the volatile phase. A dry powder was obtained from this step. Step 9) Third Heating: The dried powder from step 8c) was heated at 350°C for 6 hours under oxygen atmosphere to obtain CEX2 with M' containing Ni, Mn, Co, and Zr, with a Ni:Mn:Co:Zr ratio of 0.84:0.07:0.09:0.007 by ICP-OES. CEX2 has a D50 of 4 μm.

[0100] Example 2 A single crystalline positive electrode active material labeled EX2.1 was prepared according to the following steps. Step 1) Preparation of Zr solution: 0.75 mol% Zr from Zr propoxide (70 wt% Zr-propoxide in n-propanol solution) was dissolved in 3 grams of ethanol. Step 2) Slurry preparation: 70 grams of the intermediate product obtained from step 7) in the preparation of CEX2 was mixed with 1.5 mol % LiOH and 3.75 mol % water, both relative to M', and 26 grams of ethanol to form a slurry. Step 3) Mixing: The Zr solution prepared from step 1) and the slurry prepared from step 2) were mixed and stirred at room temperature for 15 hours, followed by filtration and drying in vacuum at 80°C for 6 hours. Step 4) Heating: The dried powder from step 3) was heated at 350°C for 6 hours under oxygen atmosphere to obtain EX2.1, which has M' containing Ni, Mn, Co, and Zr with a Ni:Mn:Co:Zr ratio of 0.84:0.07:0.09:0.007 by ICP-OES. EX2.1 has a D50 of 4 μm.

[0101] EX2.2 was prepared according to the same method as EX2.1, except that 0.6 mol% Zr from Zr propoxide was used in step 1) and 1.2 mol% Li from LiOH and 3 mol% HO were used in step 2). EX2.2 has an M' containing Ni, Mn, Co, and Zr, with a Ni:Mn:Co:Zr ratio of 0.84:0.07:0.09:0.006 obtained by ICP-OES. EX2.2 has a D50 of 4 μm.

[0102] EX2.3 was prepared according to the same method as EX2.1, except that 0.45 mol% Zr from Zr propoxide was used in step 1) and 0.9 mol% Li from LiOH and 2.25 mol% HO were used in step 2). EX2.3 has an M' containing Ni, Mn, Co, and Zr, with a Ni:Mn:Co:Zr ratio of 0.84:0.07:0.09:0.004 as determined by ICP-OES. EX2.3 has a D50 of 4 μm.

[0103] Comparative Example 3 A single-crystalline positive electrode active material, labeled CEX3, was prepared according to the following steps. Step 1) Preparation of transition metal oxide hydroxide precursor: Metal composition Ni 0.63 Mn 0.22 Co 0.15 Nickel-based transition metal oxide hydroxide powder (TMH3) with SiO2 was prepared by a co-precipitation process in a large-scale continuous stirred tank reactor (CSTR) containing mixed nickel manganese cobalt sulfate, sodium hydroxide, and ammonia. Step 2) First Mixing: The TMH3 prepared in step 1) was mixed with Li2CO3 in an industrial blender to obtain a first mixture with a lithium to metal M' (Li / M') ratio of 0.85. Step 3) First heating: The first mixture from step 2) was heated at 900°C for 10 hours under a dry air atmosphere to obtain a first heating cake. Step 4) Second Mixing: The first cooked cake from step 3) was mixed with LiOH in an industrial blender to obtain a second mixture with a lithium to metal M' (Li / M') ratio of 1.05. Step 5) Second Heating: The second mixture from step 4) was heated at 950°C under dry air for 10.2 hours, followed by wet milling, drying, and sieving to obtain the second heating product. Step 6) Third Mixing: The second heating product from step 5) was mixed with 2 mol% CO3O4 and 5 mol% LiOH, relative to the total molar contents of Ni, Mn, and Co, respectively, to obtain a third mixture. Step 7) Third Heating: The third mixture from step 6) was heated at 775° C. for 12 hours under dry air to produce an intermediate product. Step 8) Wet mixing: Zr was introduced into the positive electrode active material by applying the following steps 8a) to 8c). Step 8a) Preparation of Zr solution: 0.46 mol% Zr from Zr propoxide (70 wt% Zr propoxide in n-propanol solution), 0.92 mol% Li from Li ethoxide powder, and ethanol solvent were mixed to form a solution, based on the total molar contents of Ni, Mn, and Co in the intermediate product, respectively. The amount of ethanol solvent was 55 wt% of the total weight of the designated intermediate product to be mixed in Step 8b). Step 8b) Mixing: The intermediate product obtained from step 7) was mixed with the Zr solution prepared in step 8a) in a heatable reactor for 20 minutes. Step 8c) Heating: Heat of 70°C was applied to the reactor of step 8b) while the reactor was connected to a vacuum pump to evaporate the volatile phase. A dry powder was obtained from this step. Step 9) Fourth Heating: The dried powder from step 8c) was heated at 350°C for 6 hours under oxygen atmosphere to obtain CEX3 with M' containing Ni, Mn, Co, and Zr, with a Ni:Mn:Co:Zr ratio of 0.62:0.22:0.16:0.004 by ICP-OES. CEX3 has a D50 of 6 μm.

[0104] Example 3 A single crystalline positive electrode active material labeled EX3 was prepared according to the following steps. Step 1) Preparation of Zr solution: 0.46 mol% Zr from Zr propoxide (70 wt% Zr-propoxide in n-propanol solution) was dissolved in 3 grams of ethanol. Step 2) Slurry preparation: 70 grams of the intermediate product obtained from step 7) in the preparation of CEX3 was mixed with 0.92 mol % LiOH and 2.3 mol % water, both relative to M', and 26 grams of ethanol to form a slurry. Step 3) Mixing: The Zr solution prepared from step 1) and the slurry prepared from step 2) were mixed and stirred at room temperature for 15 hours, followed by filtration and drying in vacuum at 80°C for 6 hours. Step 4) Heating: The dried powder from step 3) was heated at 350°C for 6 hours under oxygen atmosphere to give EX3, which has M' containing Ni, Mn, Co, and Zr with Ni:Mn:Co:Zr ratio of 0.62:0.22:0.16:0.004 by ICP-OES. EX2.1 has a D50 of 6 μm.

[0105] Comparative Example 4 A polycrystalline positive electrode active material labeled CEX4 was prepared according to the following steps. Step 1) Preparation of transition metal oxide hydroxide precursor: Metal composition Ni 0.83 Mn 0.12 Co 0.05 A nickel-based transition metal oxide hydroxide powder (TMH4) with SiO2 was prepared by a co-precipitation process in a large-scale continuous stirred tank reactor (CSTR) containing mixed nickel manganese cobalt sulfate, sodium hydroxide, and ammonia. Step 2) First Mixing: The TMH4 prepared in step 1) was mixed with LiOH in an industrial blender to obtain a first mixture with a lithium to metal ratio of 0.96. Step 3) First heating: The first mixture from step 2) was heated at 765°C for 10 hours under an oxidizing atmosphere to obtain a first heating product, which was then crushed and sieved. Step 4) Second mixing: The first heating product from step 3) and LiOH as a lithium source were homogeneously mixed in an industrial blending device with a lithium to metal M′ (Li / M′) ratio of 1.02 to obtain a second mixture. Step 5) Second heating: The second mixture from step 4) was heated at 780° C. for 12 hours under an oxygen atmosphere to obtain an intermediate product. Step 6) Wet mixing: Zr was introduced into the positive electrode active material by applying the following steps 6a) to 6c). Step 6a) Preparation of Zr solution: 0.63 mol% Zr from Zr propoxide (70 wt% Zr propoxide in n-propanol solution), 1.26 mol% Li from Li ethoxide powder, and ethanol solvent were mixed to form a solution, based on the total molar contents of Ni, Mn, and Co in the intermediate product, respectively. The amount of ethanol solvent was 55 wt% of the total weight of the designated intermediate product to be mixed in Step 6b). Step 6b) Mixing: The intermediate product obtained from step 5) was mixed with the Zr solution prepared in step 6a) in a heatable reactor for 20 minutes. Step 6c) Heating: Heat of 70°C was applied to the reactor of step 6b) while the reactor was connected to a vacuum pump to evaporate the volatile phase. A dry powder was obtained from this step. Step 7) Third Heating: The dried powder from step 6c) was heated at 350°C for 6 hours under oxygen atmosphere to obtain CEX4 with M' containing Ni, Mn, Co, and Zr, with a Ni:Mn:Co:Zr ratio of 0.82:0.12:0.05:0.006 as determined by ICP-OES. CEX4 has a D50 of 6 μm.

[0106] Example 4 A polycrystalline positive electrode active material labeled EX4 was prepared according to the following steps. Step 1) Preparation of Zr solution: 0.63 mol% Zr from Zr propoxide (70 wt% Zr-propoxide in n-propanol solution) was dissolved in 3 grams of ethanol. Step 2) Slurry preparation: 70 grams of the intermediate product obtained from step 5) in the preparation of CEX4 was mixed with 1.26 mol % LiOH and 3.15 mol % water, both relative to M', and 26 grams of ethanol to form a slurry. Step 3) Mixing: The Zr solution prepared from step 1) and the slurry prepared from step 2) were mixed and stirred at room temperature for 15 hours, followed by filtration and drying in vacuum at 80°C for 6 hours. Step 4) Heating: The dried powder from step 3) was heated at 350°C for 6 hours under oxygen atmosphere to give EX3 with M' containing Ni, Mn, Co, and Zr with Ni:Mn:Co:Zr ratio of 0.83:0.120:0.050:0.006 as determined by ICP-OES. EX4 has a D50 of 6 μm.

[0107] Comparative Example 5 A polycrystalline positive electrode active material labeled CEX5 was prepared according to the following steps. Step 1) Preparation of transition metal oxide hydroxide precursor: Metal composition Ni 0.625 Mn 0.175 Co 0.200 A nickel-based transition metal oxide hydroxide powder (TMH5) with SiO2 was prepared by a co-precipitation process in a large-scale continuous stirred tank reactor (CSTR) containing mixed nickel manganese cobalt sulfate, sodium hydroxide, and ammonia. Step 2) First Mixing: The transition metal-based oxide hydroxide precursor and LiOH as the lithium source were homogeneously mixed in an industrial blending device at a lithium to metal M′ (Li / M′) ratio of 1.03 to obtain a first mixture. Step 3) First heating: The first mixture from step 2) was heated at 830°C for 10 hours under an oxygen atmosphere. The heated product was crushed, classified and sieved to obtain an intermediate product. Step 4) Wet mixing: Zr was introduced into the positive electrode active material by applying the following steps 4a) to 4c). Step 4a) Preparation of Zr solution: 0.25 mol% Zr from Zr propoxide (70 wt% Zr propoxide in n-propanol solution), 0.5 mol% Li from Li ethoxide powder, and ethanol solvent were mixed to form a solution, based on the total molar contents of Ni, Mn, and Co in the intermediate product, respectively. The amount of ethanol solvent was 55 wt% of the total weight of the designated intermediate product to be mixed in Step 4b). Step 4b) Mixing: The intermediate product obtained from step 3) was mixed with the Zr solution prepared in step 4a) in a heatable reactor for 20 minutes. Step 4c) Heating: Heat of 70°C was applied to the reactor of step 4b) while the reactor was connected to a vacuum pump to evaporate the volatile phase. A dry powder was obtained from this step. 5) Second heating: The dried powder from step 4c) was heated at 350°C for 6 hours under oxygen atmosphere to give CEX5 with M' containing Ni, Mn, Co, and Zr with Ni:Mn:Co:Zr ratio of 0.62:0.17:0.20:0.002 by ICP-OES. CEX3.2 has a D50 of 10 μm.

[0108] Example 5 A polycrystalline positive electrode active material labeled EX5 was prepared according to the following steps. Step 1) Preparation of Zr solution: 0.25 mol% Zr from Zr propoxide (70 wt% Zr-propoxide in n-propanol solution) was dissolved in 3 grams of ethanol. Step 2) Slurry preparation: 70 grams of the intermediate product obtained from step 3) in the preparation of CEX5 was mixed with 0.5 mol % LiOH and 1.25 mol % water, both relative to M', and 26 grams of ethanol to form a slurry. Step 3) Mixing: The Zr solution prepared from step 1) and the slurry prepared from step 2) were mixed and stirred at room temperature for 15 hours, followed by filtration and drying in vacuum at 80°C for 6 hours. Step 4) Heating: The dried powder from step 3) was heated at 350°C for 6 hours under oxygen atmosphere to give EX3 with M' containing Ni, Mn, Co, and Zr with Ni:Mn:Co:Zr ratio of 0.62:0.17:0.20:0.002 as determined by ICP-OES. EX5 has a D50 of 10 μm.

[0109] [Table 4] * For the molar contents of Ni, Mn, Co and Zr

[0110] Table 3 summarizes the composition, surface area, and corresponding electrochemical properties of the examples and comparative examples. x indicates the atomic ratio (molar ratio) of Zr to the total atomic fraction of Ni, Mn, Co, and Zr. Zr greater than 0 x indicates that Zr is present on the surface of the positive electrode active material in conjunction with XPS measurements where the signal is acquired from the top of the sample, i.e., the first few nanometers (e.g., 1 nm to 10 nm) of the surface layer.

[0111] CEX1 and EX1 are single-crystal positive electrode active materials with a Ni content of approximately 78.4 mol% and a Zr content of approximately 0.72 mol%. Due to differences in the Zr incorporation process, EX1 has a lower carbon content and a higher Zr content than CEX1. x Higher Zr x It is further observed that the C ratio is related to improved efficiency of solid state batteries.

[0112] CEX2 and EX2.1 are single crystal positive electrode active materials having a Ni content of approximately 83.6 mol% and a Zr content of approximately 0.67 mol%. EX2.1 prepared according to the method of the present invention has a higher Zr content compared to CEX2. x EX2.2 and EX2.3 contain Zr in amounts of 0.56 mol % and 0.40 mol %, respectively. Both Examples / Comparative Examples contain the same Zr as EX2.1.x and C to achieve improved battery efficiency.

[0113] The present invention was further illustrated by comparing CEX3 with EX3, CEX4 with EX4, and CEX5 with EX5. CEX3 and EX3 are single-crystal cathode active materials having a Ni content of approximately 61.7 mol% and a Zr content of approximately 0.41 mol%. CEX4 and EX4 are polycrystalline cathode active materials having a Ni content of approximately 82.5 mol% and a Zr content of approximately 0.57 mol%. Finally, CEX5 and EX5 are polycrystalline cathode active materials having a Ni content of approximately 62.4 mol% and a Zr content of approximately 0.25 mol%. All of these examples have a higher Zr content than the comparative examples. x The results show improved efficiency related to the ratio of Ni to C. The present invention works with both single crystal and polycrystalline materials, with Ni ranging from 55.0 mol % to 95.0 mol %.

Claims

1. A cathode active material for a solid-state battery, the cathode active material comprising Li, M′, and oxygen, wherein M′ is Ni with a content x, where 55.0 mol%≦x≦95.0 mol%, Mn with a content y of 0.0 mol%≦y≦40.0 mol%; Co with a content z of 0.0 mol%≦z≦40.0 mol%; D having a content a of 0.0 mol%≦a≦2.0 mol%, where D is at least one element other than Li, Ni, Mn, Co, and O; Zr having a content b of 0.01 mol%≦b≦5.0 mol%, x, y, z, a, and b are measured by ICP-OES; x+y+z+a+b is 100.0 mol%, The positive electrode active material has a Zr content of Zr ｘ and Zr ｘ is determined by XPS analysis, Zr ｘ is expressed as a mole fraction compared to the sum of the mole fractions of Co, Mn, Ni, and Zr as determined by XPS analysis; the positive electrode active material contains carbon in an amount C measured by a carbon analyzer, where C is in wt% based on the total weight of the positive electrode active material; Zr ｘ The ratio of C to SiO2 is 52-0.413 x to 42-0.413 x (wt%). －１ This is the positive electrode active material.

2. 2. The positive electrode active material according to claim 1, wherein D is at least one element other than Li, Ni, Mn, Co, Zr, and O.

3. 2. The positive electrode active material of claim 1, wherein D comprises at least one element selected from the group consisting of Al, B, Ba, Ca, Cr, Fe, Mg, Mo, Nb, S, Si, Sr, Ti, Y, V, W, and Zn, or at least one element selected from the group consisting of Al, B, Cr, Nb, S, Si, Ti, Y, and W.

4. Zr ｘ and C ratio is 50-0.413 x to 43-0.413 x (wt%) －１ The positive electrode active material according to claim 1 ,

5. 2. The positive electrode active material of claim 1, wherein C≦0.15 wt %, based on the total weight of the positive electrode active material.

6. It has a surface area SA determined by BET measurement, and the ratio of C to SA is at most 0.25 wt.% (g / m ２ 2. The positive electrode active material according to claim 1, wherein

7. The positive electrode active material according to claim 1 , wherein 60.0 mol %≦x≦90.0 mol %.

8. The positive electrode active material according to claim 1 , wherein 0.05 mol %≦b≦2.5 mol %.

9. The positive electrode active material according to claim 1 , wherein the positive electrode active material is a polycrystalline powder.

10. 9. The cathode active material of claim 8, wherein the secondary particle median diameter D50 is at least 2.0 μm and at most 15.0 μm, as determined by laser diffraction particle size analysis.

11. A method for producing the positive electrode active material according to claim 1, comprising: Preparing a slurry of a lithium transition metal-based oxide compound, Li, water, and alcohol; mixing the slurry with a Zr source; and heating the mixture at a temperature of 250° C. to 500° C. in an oxidizing atmosphere in a furnace for a time period of 1 hour to 20 hours to obtain the positive electrode active material.

12. 12. The method of claim 11, comprising the further step of filtering and drying the mixture before heating the mixture.

13. The method of claim 11, wherein the Zr source is Zr-propoxide.

14. 12. The method of claim 11, wherein the amount of water in the slurry is 0.5 mol % to 25.0 mol % relative to the metal content in the lithium transition metal oxide compound.

15. The method according to any one of claims 11 to 14, wherein the positive electrode active material is the positive electrode active material according to any one of claims 1 to 10.

16. A solid-state battery comprising the positive electrode active material according to any one of claims 1 to 10.

17. 17. The solid-state battery of claim 16, comprising a sulfide-based solid electrolyte comprising Li, P, and S.

18. 17. Use of the battery of claim 16 in any one of a portable computer, a tablet, a mobile phone, an energy storage system, an electric vehicle, or a hybrid electric vehicle.

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