Coated particulate electrode active material

Abstract

Composition Li 1+x TM 1-x O2 (where x is in the range of -0.02 to +0.05, and T M is at least 94 mol % nickel and up to 6 mol % of at least three metals M selected from Co, Mn, Cu, Mg, Fe, B, Al, Ce, Sn, Zr, Zn, Nb, Ta, Y, Mo, and W). 1 a particulate material comprising The metal M 1 is concentrated on the outer surface of the secondary particles of the particulate material, The particulate material has an average particle size (D50) in the range of 2 to 20 μm.

Description

[Technical Field]

[0001] The present invention relates to a compound having the composition Li 1+x TM 1-x O2 (where x is in the range of -0.02 to +0.05, and T M is at least 94 mol % nickel and up to 6 mol % of at least three metals M selected from Co, Mn, Cu, Mg, Fe, Ga, B, Al, Ce, Sn, Zr, Zn, Nb, Ta, Y, Mo, and W). 1 the particulate material is composed of secondary particles that are aggregates of primary particles, The metal M 1 is concentrated on the outer surface of the secondary particles of the particulate material, The particulate material has an average particle size (D50) in the range of 2 to 20 μm. [Background technology]

[0002] Currently, lithiated transition metal oxides are used as electrode active materials in lithium-ion batteries. Extensive research and development has been conducted over the past few years to improve not only properties such as charge density and specific energy, but also other properties such as reduced cycle life and capacity loss, which can adversely affect the life or applicability of lithium-ion batteries. Further efforts are being made to improve manufacturing methods.

[0003] Many of the electrode active materials currently under discussion are of the lithiated nickel-cobalt-manganese oxide ("NCM material") or lithiated nickel-cobalt-aluminum oxide ("NCA material") type.

[0004] In a typical process for preparing cathode materials for lithium-ion batteries, a transition metal is first co-precipitated as a carbonate, oxide, or preferably as a hydroxide, which may or may not be basic, to form a so-called precursor. The precursor is then mixed with a lithium salt, such as, but not limited to, LiOH, Li2O, or especially Li2CO3, and calcined at high temperatures. The lithium salt(s) can be used as hydrate(s) or in dehydrated form. The calcination or calcination, also commonly referred to as thermal or heat treatment of the precursor, is typically carried out at temperatures ranging from 600 to 1,000°C. During the heat treatment, a solid-state reaction occurs to form the electrode active material. When hydroxides or carbonates are used as precursors, water or carbon dioxide is removed after the solid-state reaction. The heat treatment is carried out in the heated zone of an oven or kiln. Summary of the Invention [Problem to be solved by the invention]

[0005] To improve the capacity of the cathode active material, it has been proposed to select a material with as high a nickel content as possible. However, with materials such as LiNiO2, a decrease in cycle life, significant gas evolution, and a strong increase in internal resistance during cycling have been observed, posing significant challenges for practical application. [Means for solving the problem]

[0006] Thus, a particulate material as defined at the outset has been found, which in the following is also referred to as the inventive material or material according to the invention.The inventive material will now be explained in more detail. DETAILED DESCRIPTION OF THE INVENTION

[0007] The material of the present invention has the formula Li 1+x TM 1-xO2 (where x is in the range of -0.02 to +0.05, and T M is at least 94 mol % nickel and up to 6 mol % of at least three metals M selected from Co, Mn, Cu, Mg, Fe, B, Al, Ce, Zr, Zn, Sn, Nb, Ta, Y, Mo, and W). 1 , preferably at least four metals M selected from Co, Mn, Mg, Fe, Ga, Al, Zr, Ta, Zn, Sn, Cu, Ce and Y 1 , more preferably at least four metals M including Co, Mn, Fe, Al and Y 1 and The metal M 1 is concentrated on the outer surface of the secondary particles of the particulate material, The material of the present invention has an average particle size (D50) in the range of 2 to 20 μm.

[0008] In one embodiment of the present invention, the material of the present invention is composed of spherical particles, i.e., particles having a spherical shape, including not only those that are exactly spherical, but also particles in which the maximum and minimum diameters of at least 90% (number average) of a representative sample differ by no more than 10%.

[0009] The material of the present invention has an average particle size (D50) in the range of 2 to 20 μm, preferably 5 to 16 μm. The average particle size can be determined, for example, by light scattering, laser diffraction, or electroacoustic spectroscopy. The particles are usually composed of agglomerates of primary particles, and the above particle size refers to the particle size of the secondary particles.

[0010] In one embodiment of the present invention, the material of the present invention is composed of secondary particles that are agglomerates of primary particles. Preferably, the material of the present invention is composed of spherical secondary particles that are agglomerates of primary particles. Even more preferably, the material of the present invention is composed of spherical secondary particles that are agglomerates of spherical primary particles or platelets.

[0011] In one embodiment of the present invention, the primary particles of the material of the present invention have an average diameter in the range of 1 to 3,000 nm, preferably 10 to 1,000 nm, and particularly preferably 50 to 500 nm. The average primary particle size can be determined, for example, by SEM or TEM. SEM is an abbreviation for scanning electron microscope, TEM is an abbreviation for transmission electron microscope, and XRD stands for X-ray diffraction.

[0012] In one embodiment of the present invention, the material of the present invention is 0.1 to 2.0 m 2 / g, the BET surface area can be determined by nitrogen adsorption after outgassing the sample at 200°C for 30 minutes or more and beyond, according to DIN ISO 9277:2010.

[0013] The TM is predominantly nickel, for example at least 94 mol %, preferably at least 95 mol %, with an upper limit of 99.5 mol % being preferred.

[0014] Although some metals are ubiquitous metals, such as sodium, calcium, or zinc, such trace amounts are not considered within the context of this invention. Trace amounts in this context mean amounts of 0.05 mole % or less relative to the total metal content of the TM.

[0015] In one embodiment of the present invention, TM is a compound of general formula (I) (Ni a M 1 1-a ) (I) (In the formula, M 1 is at least four metals M selected from Co, Mn, Mg, Fe, Ga, Al, Zr, Ta, Zn, Sn, Cu, Ce and Y 1 and more preferably at least five of the above metals M including Co, Mn, Fe, Al and Y. 1 It is a combination of a is in the range of 0.97 to 0.995) It is a combination of metals.

[0016] In one embodiment of the present invention, different metals M 1 The molar amounts of each metal M 1 The molar amounts of the most abundant metals M in the materials of the present invention are approximately the same. 1 The molar amount of the rarest metal M in each of the materials of the present invention is 1 and differs from each other by at most 25 mol %, preferably at most 10 mol %, and even more preferably at most 5 mol %.

[0017] In the material of the present invention, the metal M 1 is enriched at the surface, said enrichment being determined by scanning electron microscopy ("SEM") of cross-sectional particles combined with energy dispersive X-ray spectroscopy (EDX) along the particle diameter. Cross-sections can be obtained by ion milling of particles embedded in resin.

[0018] In certain embodiments of the present invention, the secondary particles of the material of the present invention are coated with a metal oxide, preferably a metal oxide that does not function as a cathode active material. Examples of suitable metal oxides include LiBO, BO, AlO, YO, LiAlO, TiO, ZrO, LiZrO, NbO, LiNbO, TaO, and LiTaO.

[0019] In one embodiment of the present invention, the materials of the present invention have an integrated peak width in the differential capacity plot (dQ) / (dV) between 4.1 and 4.25 V of at least 25 mV at the second charge cycle at a 0.2 C rate. Such materials of the present invention are particularly useful because they exhibit superior cycling stability and reduced resistance growth compared to materials with narrower peak widths.

[0020] The differential capacitance plot is typically calculated by differentiating the capacitance Q and voltage V according to Eq. 1: (dQ) / (dV) = (Q t - Q t -1) / (V t -V t - 1) (Eq. 1) (In the formula, V t , Q t are the voltage V and capacitance Q measured at time t, and V t-1 and Q t-1 are the corresponding voltage and capacitance measured at the previous time t-1). At typical C rates of 0.1-1C, data points are typically measured every 30-60 seconds or after a predefined voltage change (e.g., 5 mV). Data points can be additionally interpolated and smoothed by appropriate software to improve the quality of the (dQ) / (dV) plot.

[0021] The integrated peak width in the differential capacity (dQ) / (dV) for the second charge at a 0.2 C rate between 4.1 and 4.25 V is defined as the integral I of the corresponding (dQ) / (dV) plot for the second charge between 4.1 and 4.25 V divided by the maximum value m of the corresponding (dQ) / (dV) plot for the second charge between 4.1 and 4.25 V, as shown in Figure 1 and defined by Eq. 1. 第2充電 IPW 4.1V~4.25V =I / m (Eq. 2) The materials of the present invention are particularly suitable as cathode active materials in lithium-ion batteries, as they combine good cycling stability with high energy density.

[0022] In one embodiment of the present invention, the cathode active material of the present invention contains Li2CO3 in the range of 0.001 to 1% by mass, based on the material of the present invention, as determined by titration as Li2CO3.

[0023] Another aspect of the present invention relates to a method for producing the material of the present invention, hereinafter also referred to as the method of the present invention or the method according to the (present) invention. The method of the present invention comprises several steps, hereinafter also referred to as step (a), step (b), etc.

[0024] Steps (a) to (e) can be characterized as follows: (a) providing particulate lithium nickel oxide; (b) adding the lithium nickel oxide to M 1 or a solution of one or two of the compounds of M 1 a step of mixing the compound with a particulate oxide or hydroxide of the compound; (c) optionally removing the solvent from step (b); (d) heat treating the solid obtained from step (b) or (c), respectively.

[0025] Steps (a) to (c) will be explained in more detail below.

[0026] In step (a), particulate lithium nickelate (hereinafter also referred to in full as LiNiO) is provided. In the context of the present invention, the term lithium nickelate is not limited to stoichiometric LiNiO, but also includes compounds with slightly deviated stoichiometries, for example, an undercut of up to 5 mol % lithium relative to nickel or an excess of up to 7 mol % lithium, respectively.

[0027] The LiNiO2 provided in step (a) has an average particle size (D50) ranging from 2 to 20 μm, preferably from 4 to 16 μm. The average particle size can be determined, for example, by light scattering, laser diffraction, or electroacoustic spectroscopy. The particles are composed of agglomerates of primary particles, and the above particle size refers to the particle size of the secondary particles.

[0028] LiNiO2 can be synthesized by precipitating nickel hydroxide, adding a lithium source such as Li2O, LiOH, or Li2CO3, and firing at 600 to 800°C in the presence of oxygen, preferably in pure oxygen.

[0029] In step (b), the nickel oxide / hydroxide is 1 or a solution of one or two of the compounds of M 1 The preferred solvent is M 1 It depends on the type of compound.

[0030] M 1 Alkanolates of M are highly soluble in the corresponding alcohols. 1 Examples of water-soluble compounds include, but are not limited to, ammonium metatungstate (hydrate), ammonium orthomolybdate, ammonium heptamolybdate, ammonium dimolybdate, ammonium oxalate niobate, and ammonium zirconium (IV) carbonate, either as such or as hydrates.

[0031] Examples of suitable compounds of Fe are Fe(NO3)3 and acetonylacetonate of Fe. Examples of suitable compounds of Ce and Y include Ce(NO3)3, Ce(OH)3, Ce2O3, Y(NO3)3, Y(OH)3 and YO3.

[0032] M 1 Examples of suitable cation compounds are Al2(SO4)3, KAl(SO4)2, and Al(NO3)3, alkanolates of Al such as, but not limited to, Al(C2H5O)3, Al-tris-isopropoxide, Mg(NO3)2, Mg(SO4)2, MgC2O4, alkanolates of Mg such as, but not limited to, Mg(C2H5O)2, NaBO2, H3BO3, BO3, alkanolates of B such as, but not limited to, B-tris-isopropoxide, Ga(NO3)3, Ga2(SO4)3, alkanolates of Ga such as, but not limited to, Ga(CHO)3, Ga-tris-isopropoxide, or a mixed salt of at least two cations such as aluminum magnesium isopropoxide. A suitable solvent for Al2(SO4)3, KAl(SO4)2, Al(NO3)3, Mg(NO3)2, Mg(SO4)2, MgC2O4, NaBO2, H3BO3, B2O3, Ga(NO3)3 and Ga2(SO4)3 is water. 1 The alkanolates are highly soluble in the corresponding alcohols.

[0033] In one embodiment of the present invention, all M 1The counterions of M may be the same or similar, for example, two different alkanolate ions. In such an embodiment, the nickel oxide / hydroxide may be 1 The compound may be treated with one solution containing the compound of formula (I).

[0034] In another embodiment of the present invention, various M 1 The counter ions are different, for example, Al nitrate and all M other than Al 1 In such an embodiment, the nickel oxide / hydroxide is an alkoxide of the Al-containing solution and all M other than Al. 1 is subsequently treated with a solution containing

[0035] In one embodiment of step (b), the solution(s) used in step (b) contain 0.001 to 60% by weight of M 1 In another embodiment of step (b), the solution used in step (b) contains a total of 0.002 to 70% by mass of M 1 Contains the compound:

[0036] In one embodiment of the present invention, M 1 The solution or at least one solution containing the compound of further contains a compound of Ni, such as nickel nitrate or a nickel alkanolate.

[0037] In an alternative embodiment of the present invention, the lithium nickelate is M 1 Particulate oxides or hydroxides of, preferably M 1 The term "hydroxide" in this context is not limited to stoichiometric hydroxides, but also includes partially dehydrated hydroxides, which may be referred to as oxyhydroxides.

[0038] M 1Examples of oxides or hydroxides of include FeO, FeOOH, Fe(OH)3, Fe2O3, Ta2O5, Y2O3, CoO, Co2O3, Co3O4, MnO, MnO2, Mn2O3, Al2O3, AlOOH, Al(OH)3, ZnO, Zn(OH)2, SnO, SnO2, CuO, ZrO(OH)2, Zr(OH)4, ZrO2, ZrO2·aq, all of the above as is and with water of crystallization.

[0039] M 1 The average diameter (D50) of the oxide or hydroxide of M is preferably in the range of 10 nm to 100 μm, preferably 20 nm to 20 μm. For example, M may have an average diameter (D50) of 100 nm to 2 μm as measured by laser diffraction or dynamic light scattering ("DLS"). 1 The so-called nanoparticulate oxides or hydroxides of the formula (I) are preferred.

[0040] In one embodiment of the present invention, step (b) is carried out at a temperature in the range of 5 to 85°C, preferably 10 to 60°C.

[0041] In one embodiment of the invention, step (b) is carried out at atmospheric pressure. However, it is preferred to carry out step (b) under elevated pressure, for example at a pressure of 10 mbar to 10 bar above atmospheric pressure, or under vacuum, for example at a pressure of 50 to 250 mbar below atmospheric pressure, preferably at a pressure of 100 to 200 mbar below atmospheric pressure.

[0042] For example, step (b) can be carried out in a vessel that can be easily drained, e.g., located above a filter device. Such a vessel can be filled with lithium nickel oxide from step (c), followed by M 1 In other embodiments, such a container may contain a solution or solutions of the compound. 1 In another embodiment, the lithium nickelate and M 1 The solutions of the compounds are introduced simultaneously.

[0043] In one embodiment of the present invention, in step (b), lithium nickel oxide and M 1 The volume ratio of the compound to the solution(s) is in the range of 10:1 to 1:5, preferably 10:1 to 1:1, and even more preferably 10:1 to 5:1.

[0044] LiNiO2 1 Treatment with the solution(s) may be carried out for a period of from 1 minute to 3 hours, preferably from 5 minutes to 1 hour, and even more preferably from 5 to 30 minutes.

[0045] Lithium nickel oxide 1 Treatment with the oxide or hydroxide of can be carried out in a ball mill, in the absence or presence of water, or by spray drying the slurry.

[0046] Step (b) may be supported by a mixing operation, for example by shaking, or especially by stirring or shearing, see below.

[0047] In one embodiment of the present invention, steps (b) and (c) are combined. In one embodiment of the present invention, step (b) comprises oxidizing the LiNiO2 from step (a) with a portion of M 1 and then removing the solvent by solid-liquid separation or evaporation (step (c-1)), and then separating the residue into the remaining M 1 and removing the solvent by solid-liquid separation or evaporation (step (c-2)), followed by drying at a maximum temperature in the range of 50 to 450°C.

[0048] In optional step (c), the solvent(s) are removed. A preferred embodiment of the solvent removal is a solid-liquid separation method, such as decantation and filtration, for example on a band filter or in a filter press. A further example is evaporation of the solvent(s).

[0049] In one embodiment of step (c), the slurry obtained in step (b) is discharged directly into a centrifuge, such as a decanter centrifuge or a filter centrifuge, or into a filter device, such as a suction filter or a belt filter, preferably located directly below the vessel in which step (b) is carried out, after which filtration begins.

[0050] In a particularly preferred embodiment of the present invention, steps (b) and (c) are carried out in a stirred filter apparatus, such as a stirred pressure filter or a stirred suction filter. 1 After combining the solution(s), solvent removal is initiated by initiating filtration after up to 3 minutes, or even immediately thereafter. On a laboratory scale, steps (b) and (c) may be performed in a Büchner funnel, and steps (b) and (c) may be supported by manual stirring.

[0051] In a preferred embodiment, step (b) is carried out in a filter apparatus, such as an agitated filter apparatus, which allows for agitation of the slurry or filter cake in the filter. Step (c) is initiated a maximum of 3 minutes after the start of step (b) by initiating filtration, such as pressure filtration or suction filtration.

[0052] In one embodiment of the present invention, the removal of the solvent according to step (c) has a duration ranging from 1 minute to 1 hour.

[0053] In one embodiment of the present invention, stirring in step (b), and, where applicable, step (c), is carried out at a speed in the range of 1 to 50 revolutions per minute ("rpm"), with 5 to 20 rpm being preferred.

[0054] In one embodiment of the present invention, the filter media can be selected from ceramic, sintered glass, sintered metal, organic polymer film, nonwoven fabric, and woven fabric.

[0055] In one embodiment of the present invention, steps (b) and (c) are carried out in an atmosphere having a reduced CO2 and / or moisture content, for example, a carbon dioxide and / or moisture content in the range of 0.01 to 500 ppm by mass, with 0.1 to 50 ppm by mass being preferred. The CO2 and / or moisture content can be determined, for example, by an optical method using infrared light. It is even more preferred to carry out steps (b) and (c) in an atmosphere having a carbon dioxide and / or moisture content below the detection limit of, for example, an optical method based on infrared light.

[0056] In one embodiment of the invention, step (c) is carried out by evaporating the solvent, preferably under reduced pressure. Such an embodiment is preferred when the solvent(s) is / are an organic solvent, such as ethanol or isopropanol.

[0057] In one embodiment of the present invention, steps (b) and (c) are carried out in an atmosphere having a reduced CO content, for example, a carbon dioxide content in the range of 0.01 to 500 ppm by mass, with 0.1 to 50 ppm by mass being preferred. The CO content can be determined, for example, by an optical method using infrared light. It is even more preferred to carry out steps (b) and (c) in an atmosphere having a carbon dioxide content below the detection limit of, for example, an optical method based on infrared light.

[0058] In one embodiment of the present invention, step (c) is carried out by evaporating the solvent, preferably under reduced pressure, or by spray drying. Such an embodiment is preferred when the solvent(s) is / are an organic solvent, such as methanol or ethanol or isopropanol. Suitable temperatures for evaporation are between 80 and 150°C.

[0059] In embodiments where step (b) is carried out in the presence of a solvent, a powdery residue is obtained from step (c).

[0060] Step (d) comprises heat treating the solid obtained from step (b) or (c), respectively. If step (c) is not performed, step (d) starts with the solid obtained from step (b).

[0061] An example of step (e) is a heat treatment at a temperature in the range of 600-800° C., preferably 650-750° C. The terms “thermal treatment” and “heat treatment” and “thermal treatment” are used interchangeably in the context of the present invention.

[0062] In one embodiment of the present invention, the mixture obtained from step (d) is heated to 600-800°C at a heating rate of 0.1-10°C / min.

[0063] In one embodiment of the present invention, the temperature is increased before reaching a desired temperature of 600 to 800° C., preferably 650 to 750° C. For example, the mixture obtained from step (d) is first heated to 350 to 550° C., then kept constant for 10 minutes to 4 hours, then heated to 650 to 800° C., and then kept at 650 to 800° C. for 10 minutes to 10 hours.

[0064] In one embodiment of the present invention, step (d) is carried out in a roller hearth kiln, a pusher kiln, or a rotary kiln, or a combination of at least two of them. A rotary kiln has the advantage that the material produced therein is very homogenized. In roller hearth kilns and pusher kilns, different reaction conditions for different steps can be set very easily. In laboratory-scale experiments, box furnaces, tube furnaces, and split tube furnaces can also be used.

[0065] In one embodiment of the present invention, step (d) is carried out in an oxygen-containing atmosphere, such as a nitrogen-air mixture, a noble gas-oxygen mixture, air, oxygen, or oxygen-enriched air. In a preferred embodiment, the atmosphere in step (d) is selected from air, oxygen, and oxygen-enriched air. The oxygen-enriched air may be, for example, a 50:50 volume ratio mixture of air and oxygen. Other options include a 1:2 volume ratio mixture of air and oxygen, a 1:3 volume ratio mixture of air and oxygen, a 2:1 volume ratio mixture of air and oxygen, and a 3:1 volume ratio mixture of air and oxygen.

[0066] In one embodiment of the present invention, step (d) is carried out under a gas flow, such as air, oxygen, and oxygen-enriched air. Such a gas flow is also called a forced gas flow. Such a gas flow is represented by the general formula Li 1+x TM 1-x O2 per kg of material, 0.5-15 m 3 The gas flow can have a specific flow rate in the range of 1 / h. The volume is determined under normal conditions (298 Kelvin and 1 atmosphere). The gas flow is useful for removing gaseous decomposition products such as water and carbon dioxide.

[0067] The method of the present invention may include a further step following step (d), such as, but not limited to, a further calcination step at a temperature in the range of 650-800°C.

[0068] In one embodiment of the invention, step (d) has a duration ranging from 1 hour to 30 hours, preferably from 10 hours to 24 hours. The time at temperatures above 600°C counts heating and holding, but cooling time is ignored in this context.

[0069] The resulting material is highly suitable as a cathode active material for lithium ion batteries.

[0070] In one embodiment of the present invention, the material of the present invention can be treated with water and then dried. In another embodiment, particles of the material of the present invention can be at least partially coated, for example, by mixing with an oxide or hydroxide, such as aluminum hydroxide or alumina, or with boric acid, followed by heat treatment at 150-400°C. In another embodiment of the present invention, particles of the material of the present invention can be at least partially coated by atomic layer deposition, for example, by alternating treatment(s) with trimethylaluminum and water.

[0071] A further aspect of the present invention is an electrode comprising at least one material of the present invention. These are also called cathodes and are particularly useful in lithium-ion batteries. Lithium-ion batteries comprising at least one electrode according to the present invention exhibit very good discharge and cycling behavior, and they also exhibit good safety behavior.

[0072] In one embodiment of the present invention, the cathode of the present invention comprises: (A) at least one material of the present invention as described above; (B) carbon in a conductive state, and (C) binder, (D) Current collector Contains:

[0073] In a preferred embodiment of the present invention, the cathode of the present invention comprises, based on the sum of (A), (B), and (C): (A) 80 to 98% by mass of the material of the present invention; (B) 1 to 17 mass% carbon; (C) 1 to 10 mass % of a binder material Contains:

[0074] The cathode according to the present invention contains a conductively modified carbon, also referred to simply as carbon (B). Carbon (B) can be selected from soot, activated carbon, carbon nanotubes, graphene, and graphite. Carbon (B) can be added directly during the preparation of the electrode material according to the present invention.

[0075] The electrodes according to the present invention may contain further components, such as a current collector (D), for example (but not limited to) aluminum foil. They may further contain a binder material (C), also referred to as binder (C) hereinafter. The current collector (D) will not be further described here.

[0076] Suitable binders (C) are preferably selected from organic (co)polymers. Suitable (co)polymers, i.e., homopolymers or copolymers, can be selected, for example, from (co)polymers obtainable by anionic (co)polymerization, catalytic (co)polymerization, or free-radical (co)polymerization, in particular from polyethylene, polyacrylonitrile, polybutadiene, polystyrene, and copolymers of at least two comonomers selected from ethylene, propylene, styrene, (meth)acrylonitrile, and 1,3-butadiene. Polypropylene is also suitable. Polyisoprene and polyacrylates are furthermore suitable. Polyacrylonitrile is particularly preferred.

[0077] In the context of the present invention, polyacrylonitrile is understood to mean not only polyacrylonitrile homopolymers but also copolymers of acrylonitrile with 1,3-butadiene or styrene, with polyacrylonitrile homopolymers being preferred.

[0078] In the context of the present invention, polyethylene refers not only to homopolyethylenes but also to copolymerized ethylene at least 50 mol % and up to 50 mol % of at least one further comonomer, such as α-olefins, for example propylene, butylene (1-butene), 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-pentene, and also isobutene, vinyl aromatics, for example styrene, and also (meth)acrylic acid, vinyl acetate, vinyl propionate, C1-C2 copolymers of (meth)acrylic acid. 10-Alkyl esters, in particular methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-butyl acrylate, 2-ethylhexyl acrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate, and also copolymers of ethylene with maleic acid, maleic anhydride and itaconic anhydride. Polyethylene can be HDPE or LDPE.

[0079] In the context of the present invention, polypropylene is understood to mean not only homopolypropylene but also copolymers of propylene with at least 50 mol % copolymerized propylene and up to 50 mol % of at least one further comonomer, such as ethylene, and α-olefins, such as butylene, 1-hexene, 1-octene, 1-decene, 1-dodecene and 1-pentene. The polypropylene is preferably isotactic or essentially isotactic polypropylene.

[0080] In the context of the present invention, polystyrene is not only a homopolymer of styrene, but also a C1-C6 copolymer of acrylonitrile, 1,3-butadiene, (meth)acrylic acid, 10 -alkyl esters, divinylbenzene, in particular 1,3-divinylbenzene, copolymers with 1,2-diphenylethylene and α-methylstyrene are also understood to mean.

[0081] Another preferred binder (C) is polybutadiene.

[0082] Other suitable binders (C) are selected from polyethylene oxide (PEO), cellulose, carboxymethyl cellulose, polyimides and polyvinyl alcohol.

[0083] In one embodiment of the present invention, the binder (C) has an average molecular weight M ranging from 50,000 g / mol to 1,000,000 g / mol, preferably up to 500,000 g / mol. W The (co)polymers are selected from the group consisting of:

[0084] The binder (C) may be a crosslinked or non-crosslinked (co)polymer.

[0085] In a particularly preferred embodiment of the present invention, the binder (C) is selected from halogenated (co)polymers, in particular fluorinated (co)polymers.Halogenated or fluorinated (co)polymers are understood to mean (co)polymers that contain at least one (co)polymerized (co)monomer having at least one halogen atom or at least one fluorine atom per molecule, more preferably at least two halogen atoms or at least two fluorine atoms per molecule.Examples include polyvinyl chloride, polyvinylidene chloride, polytetrafluoroethylene, polyvinylidene fluoride (PVdF), tetrafluoroethylene-hexafluoropropylene copolymer, vinylidene fluoride-hexafluoropropylene copolymer (PVdF-HFP), vinylidene fluoride-tetrafluoroethylene copolymer, perfluoroalkyl vinyl ether copolymer, ethylene-tetrafluoroethylene copolymer, vinylidene fluoride-chlorotrifluoroethylene copolymer, and ethylene-chlorofluoroethylene copolymer.

[0086] Suitable binders (C) are especially polyvinyl alcohol and halogenated (co)polymers such as polyvinyl chloride or polyvinylidene chloride, especially fluorinated (co)polymers such as polyvinyl fluoride and especially polyvinylidene fluoride and polytetrafluoroethylene.

[0087] The electrode of the present invention may contain 3 to 10 mass % of binder(s) (d) based on the total mass of the component (a), the component (b) and the carbon (c).

[0088] A further aspect of the present invention is (A) at least one cathode comprising the cathode active material (A) of the present invention, carbon (B), and a binder (C); (B) at least one anode, and (C) at least one electrolyte It is a battery containing

[0089] The embodiment of the cathode (1) has already been described in detail above.

[0090] The anode (2) may contain at least one anode active material, such as carbon (graphite), TiO2, lithium titanium oxide, silicon, or tin. The anode (2) may further contain a current collector, such as a metal foil, such as copper foil.

[0091] The electrolyte (3) may include at least one non-aqueous solvent, at least one electrolyte salt, and optionally an additive.

[0092] The non-aqueous solvent for the electrolyte (3) can be liquid or solid at room temperature and is preferably selected from polymers, cyclic or acyclic ethers, cyclic and acyclic acetals, and cyclic or acyclic organic carbonates.

[0093] Examples of suitable polymers are, in particular, polyalkylene glycols, preferably poly-C1-C4-alkylene glycols, and especially polyethylene glycols, where the polyethylene glycols may contain up to 20 mol % of one or more C1-C4-alkylene glycols. The polyalkylene glycols are preferably polyalkylene glycols with two methyl or ethyl end caps.

[0094] The molecular weight M of suitable polyalkylene glycols, especially suitable polyethylene glycols, W may be at least 400 g / mol.

[0095] The molecular weight M of suitable polyalkylene glycols, especially suitable polyethylene glycols, W can be up to 5,000,000 g / mol, preferably up to 2,000,000 g / mol.

[0096] Examples of suitable acyclic ethers are, for example, diisopropyl ether, di-n-butyl ether, 1,2-dimethoxyethane, 1,2-diethoxyethane, with 1,2-dimethoxyethane being preferred.

[0097] Examples of suitable cyclic ethers are tetrahydrofuran and 1,4-dioxane.

[0098] Examples of suitable acyclic acetals are, for example, dimethoxymethane, diethoxymethane, 1,1-dimethoxyethane and 1,1-diethoxyethane.

[0099] An example of a suitable cyclic acetal is 1,3-dioxane, and especially 1,3-dioxolane.

[0100] Examples of suitable acyclic organic carbonates are dimethyl carbonate, ethyl methyl carbonate and diethyl carbonate.

[0101] Examples of suitable cyclic organic carbonates are compounds of the general formulae (II) and (III) [ka] (In the formula, R 1 , R 2 and R 3 can be the same or different and are selected from hydrogen and C1-C4-alkyl, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl and tert-butyl, preferably R 2 and R 3 (Both cannot be tert-butyl).

[0102] In a particularly preferred embodiment, R 1 is methyl and R 2 and R 3 are each hydrogen or R 1 , R 2 and R 3 are hydrogen atoms.

[0103] Another preferred cyclic organic carbonate is vinylene carbonate of formula (IV).

[0104] [ka]

[0105] Preferably, the solvent or solvents are used in an anhydrous state, ie with a water content in the range of 1 ppm to 0.1% by weight, which can be determined, for example, by Karl Fischer titration.

[0106] The electrolyte (3) further comprises at least one electrolyte salt. Suitable electrolyte salts are, in particular, lithium salts. Examples of suitable lithium salts are LiPF, LiBF, LiClO, LiAsF, LiCF, SO, LiC(C n F 2n+1 SO2)3, lithium imide, e.g., LiN(C n F 2n+1 SO2)2 (wherein n is an integer ranging from 1 to 20), LiN(SO2F)2, Li2SiF6, LiSbF6, LiAlCl4, and compounds of the general formula (C n F 2n+1 SO2) t YLi salt wherein t=1 when Y is selected from oxygen and sulfur; when Y is selected from nitrogen and phosphorus, t=2; When Y is selected from carbon and silicon, t=3).

[0107] Preferred electrolyte salts are selected from LiC(CF3SO2)3, LiN(CF3SO2)2, LiPF6, LiBF4, LiClO4, with LiPF6 and LiN(CF3SO2)2 being particularly preferred.

[0108] Preferably, the electrolyte (3) contains at least one flame retardant. Useful flame retardants may be selected from trialkyl phosphates (where the alkyls are different or the same), triaryl phosphates, alkyl dialkyl phosphonates, and halogenated trialkyl phosphates. Preferred are tri-C1-C4-alkyl phosphates (where the C1-C4-alkyls are different or the same), tribenzyl phosphate, triphenyl phosphate, C1-C4-alkyl di-C1-C4-alkyl phosphonates, and fluorinated tri-C1-C4-alkyl phosphates.

[0109] Preferably, the electrolyte (3) contains at least one flame retardant selected from trimethyl phosphate, CH3-P(O)(OCH3)2, triphenyl phosphate, and tris-(2,2,2-trifluoroethyl) phosphate.

[0110] The electrolyte (3) may contain 1 to 10 mass % of a flame retardant based on the total mass of the electrolyte.

[0111] In an embodiment of the present invention, the battery according to the present invention includes one or more separators (4) by which the electrodes are mechanically separated. Preferred separators (4) are polymer films, particularly porous polymer films, that are unreactive with metallic lithium. Particularly preferred materials for separators (4) are polyolefins, particularly film-forming porous polyethylene and film-forming porous polypropylene.

[0112] The separator (4) made of polyolefin, particularly polyethylene or polypropylene, can have a porosity in the range of 35 to 45%. The preferred pore size is, for example, in the range of 30 to 500 nm.

[0113] The separator (4) can be selected from PET nonwoven fabrics filled with inorganic particles. Such separators can have a porosity in the range of 40 to 55%. Suitable pore sizes are, for example, in the range of 80 to 750 nm.

[0114] The battery according to the invention may further comprise a housing which may have any shape, for example a cube or a cylindrical disk. In one variant, a metal foil configured as a pouch is used as the housing.

[0115] The cells according to the invention exhibit very good discharge and cycling behaviour, especially with regard to capacity loss, especially at high temperatures (above 45° C., for example up to 60° C.).

[0116] The battery according to the present invention may comprise two or more electrochemical cells that are combined with one another, for example, connected in series or in parallel. A series connection is preferred. In the battery according to the present invention, at least one electrochemical cell contains at least one cathode according to the present invention. Preferably, in the electrochemical cell according to the present invention, the majority of the electrochemical cells contain cathodes according to the present invention. Even more preferably, in the battery according to the present invention, all electrochemical cells contain cathodes according to the present invention.

[0117] The present invention further provides a method for using the battery according to the present invention in a device, in particular a mobile device. Examples of mobile devices are vehicles, such as automobiles, bicycles, aircraft, or water vehicles, such as boats or ships. Other examples of mobile devices are manually operated devices, such as computers, in particular laptops, telephones, or powered hand tools, for example in the construction sector, in particular drills, battery-powered screwdrivers, or battery-powered staplers.

[0118] The present invention is further illustrated by examples. [Example]

[0119] The average particle size (D50) was determined by dynamic light scattering ("DLS"). Percentages are by weight unless otherwise stated.

[0120] I. Preparation of base cathode active material LiNiO I.1 Precursor preparation Step (a.1): A spherical Ni(OH) precursor was obtained by combining an aqueous solution of nickel sulfate (1.65 mol / kg solution) with a 25 wt% NaOH solution, using ammonia as a complexing agent. The pH value was set to 12.6. The newly precipitated Ni(OH) was washed with water, sieved, and dried at 120 °C for 12 h. The newly precipitated Ni(OH) was then poured into an alumina crucible and dried in a furnace under oxygen atmosphere (10 exchanges / h) at 500 °C for 3 h, using a heating rate of 3 °C / min and a cooling rate of 10 °C / min, to obtain precursor p-CAM.1. The resulting p-CAM.1 was NiO with a D50 of 6 μm.

[0121] I.2 Preparation of LiNiO2 as a base cathode active material The dehydrated precursor p-CAM.1 was mixed with LiOH·H2O in a molar ratio of 1.01:1 Li:Ni, poured into an alumina crucible, and heated at 350 °C for 4 h and 700 °C for 6 h under an oxygen atmosphere (10 exchanges / h) using a heating rate of 3 °C / min. The resulting material was cooled to room temperature at a cooling rate of 10 °C / min and then sieved through a 30 μm mesh size to obtain LiNiO2 with a D50 of 6 μm (hereinafter also referred to as B-CAM.1) as the base cathode active material.

[0122] II. Preparation of the Cathode Active Material of the Present Invention II.1 Manufacturing of CAM.1 Step (b.1): 10 mmol each of Co(NO3)2, Mn(NO3)2, Ni(NO3)2, Mg(NO3)2, Fe(NO3)3, Ga(NO3)3, Al(NO3)3, Ce(NO3)3, and Y(NO3)3 were mixed in a beaker. Water was added until a clear solution was formed. A total of 2 mol% M, relative to Ni in B-CAM.1, was added. 1 The amount of solution corresponding to the above M was added dropwise to 20 g of B-CAM.1 over a period of 5 minutes at room temperature. 1 More water was added so that the mixture was completely impregnated with the solution containing

[0123] Step (c.1): Then, water was evaporated at normal pressure at 120°C for 1 hour.

[0124] Step (d.1): The powdered solid obtained from step (c.1) was then poured into an alumina crucible and heated at 500°C for 1 hour under an oxygen atmosphere (10 exchanges / h) using a heating rate of 3°C / min and a subsequent cooling rate of 10°C / min. The material thus obtained was then sieved using a mesh size of 32 μm to obtain the cathode active material CAM.1 of the present invention. SEM-EDX revealed that the metal M 1 It can be demonstrated that is concentrated on the outer surface of the secondary particles of CAM.1.

[0125] II.2 Manufacturing of CAM.2 The protocol of II.1 was followed, but step (d.2) was carried out at 700 °C instead of 500 °C. CAM.2 was obtained. SEM-EDX revealed that the metal M 1 It can be demonstrated that is concentrated on the outer surface of the secondary particles of CAM.2.

[0126] II.3 Manufacturing of CAM.3 Step (b.1): 10 mmol each of Co(NO3)2, Mn(NO3)2, Ni(NO3)2, Mg(NO3)2, Fe(NO3)3, Ga(NO3)3, Al(NO3)3, Ce(NO3)3, and Y(NO3)3 were mixed in a beaker. Methanol was added until a clear solution was formed. A total of 2 mol% M, relative to Ni in B-CAM.1, was added. 1 The amount of solution corresponding to the above M was added dropwise to 20 g of B-CAM.1 over a period of 5 minutes at room temperature. 1 More methanol was added to ensure complete impregnation with the solution containing

[0127] Step (c.3): Then, the methanol was evaporated at normal pressure at 120° C. for 1 hour.

[0128] Step (d.3): The powdered solid obtained from step (c.1) was then poured into an alumina crucible and heated at 500°C for 1 hour under an oxygen atmosphere (10 exchanges / h) using a heating rate of 3°C / min and a subsequent cooling rate of 10°C / min. The material thus obtained was then sieved using a mesh size of 30 μm to obtain the cathode active material CAM.3 of the present invention. SEM-EDX revealed that the metal M 1 It can be demonstrated that is concentrated on the outer surface of the secondary particles of CAM.3.

[0129] II.4 Manufacturing of CAM.4 The protocol of II.3 was followed, but step (d.4) was carried out at 700 °C instead of 500 °C. CAM.4 was obtained. SEM-EDX revealed that the metal M 1 It can be demonstrated that is concentrated on the outer surface of the secondary particles of CAM.4.

[0130] II.5 Manufacturing of CAM.5 Step (b.5): Equimolar amounts of the following nanoparticle oxides were mixed in a planetary mixer: Co3O4, Mn3O4, Y2O3, Al2O3, Ta2O5, ZnO, SnO2, CuO, Fe2O3, and Zr(OH)4. The duration of mixing was 5 minutes at 1000 revolutions per minute ("rpm"). Next, 5 g of the above mixture was added to 95 g of B-CAM.1 and mixed in a planetary mixer at 1000 rpm for 2 minutes.

[0131] Step (c) was not performed.

[0132] Step (d.5): The powdered solid obtained from step (b.5) was then poured into an alumina crucible and heated at 500°C for 1 hour under an oxygen atmosphere (10 exchanges / h) using a heating rate of 3°C / min and a subsequent cooling rate of 10°C / min. The material thus obtained was then sieved using a mesh size of 30 μm to obtain the cathode active material CAM.5 of the present invention. SEM-EDX revealed that the metal M 1 It can be demonstrated that is concentrated on the outer surface of the secondary particles of CAM.5.

[0133] II.6 Manufacturing of CAM.6 The protocol of II.5 was followed, but step (d.6) was carried out at 700 °C instead of 500 °C. CAM.6 was obtained. SEM-EDX revealed that the metal M 1 It can be demonstrated that is concentrated on the outer surface of the secondary particles of CAM.6.

[0134] III. Electrochemical Testing III.1 Cathode fabrication, general protocol: Electrode Fabrication: Electrodes contained 94% of each CAM or B-CAM.1, 3% carbon black (Super C65), and 3% binder (polyvinylidene fluoride, Solef 5130). A slurry with 61% total solids was mixed in N-methyl-2-pyrrolidone (planetary mixer, 2000 rpm, 24 minutes) and cast onto aluminum foil tape using a box coater. The electrode tape was dried in a vacuum at 120°C for 16 hours and calendered. After that, circular electrodes with a diameter of 14 mm were punched out, weighed, and dried in a vacuum at 120°C for 12 hours before being placed in an Ar-filled glove box. The average weight gain was 8 mg / cm. 2 and the electrode density is 3 g / cm 3 It was.

[0135] III.2 Coin Cell Manufacturing The coin-type electrochemical cell was assembled in an argon-filled glove box. The anode was a 0.58 mm thick Li foil, separated from the cathode by a glass fiber separator (Whatman GF / D). The electrolyte was 1 M LiPF6 in a 3:7 mass ratio of ethylene carbonate (EC):ethyl methyl carbonate (EMC), in a volume of 95 μl. After assembly, the cell was crimped closed using an automatic crimping machine. The cell was then transferred to a climate chamber and connected to a Batley cycler (Series 4000, MACCOR).

[0136] III.3 Coin Cell Testing All tests were performed at 25°C. Cells were galvanostatically cycled in a Maccor 4000 battery cycler at room temperature between 3.1 and 4.3 V by applying the following C rates until 70% of the initial discharge capacity was reached at the specified discharge step:

[0137] The test protocol consisted of an initial formation and rate test portion, which began with two cycles at C / 10. The voltage window was set to 3.0–4.3 V for all cycles. The initial 1 C rate was 200 mA g -1 In all subsequent cycles, charging was set to CCCV at C / 2 and 4.3 V for 30 minutes or until the current dropped below C / 100. The cells were discharged at C / 5 for 5 cycles, followed by stepwise increasing discharge rates (C / 10, C / 5, C / 2, 1 C, 2 C, 3 C). The 1 C rate was then adapted to the capacity of the 1 C discharge. After the rate test, the state-of-charge dependent cell resistance was determined by the DCIR method. After a short potential relaxation, a 400 mA g -1 Current pulses of 100 mA g were applied for 10 seconds. After each current pulse, the cell was discharged at C / 5 for 30 minutes, then cycled until the cell voltage dropped below 3 V. After this initial period, the cell was cycled alternately at C / 10 for 2 cycles and 1 C for 50 cycles. During each second C / 10 cycle, the cell potential was relaxed at 100%, 50%, and 25% SOC for 5 minutes, followed by a 100 mA g -1 A current pulse was applied for 30 seconds at 2.5 C, and the cell resistance was calculated using the DCIR method. A 2.5 C rate discharge pulse was applied for 30 minutes.

[0138] [Table 1]

Claims

1. Composition Li １＋ｘ TM １－ｘ O ２ where x is in the range of −0.02 to +0.05, and T M is at least 94 mol % nickel and up to 6 mol % of at least three metals M selected from Co, Mn, Cu, Mg, Fe, Ga, B, Al, Ce, Sn, Zr, Zn, Nb, Ta, Y, Mo, and W. １ a particulate material comprising the particulate material is composed of secondary particles that are aggregates of primary particles, The metal M １ is concentrated on the outer surface of the secondary particles of the particulate material, the particulate material has an average particle size (D50) in the range of 2 to 20 μm; The most abundant metal M in said particulate material １ is the molar amount of the rarest metal M １ The particulate material is characterized in that the molar amount of

2. TM is a compound represented by the general formula (I) (In a M 1 1-a ) (I) (In the formula, M １ is a combination of at least four of Co, Mn, Mg, Fe, Ga, Al, Ce, Zr, Ta, Zn, Sn, Cu, and Y; a is in the range of 0.97 to 0.995) 2. The particulate material of claim 1, wherein the metal combination is:

3. M １ 3. The particulate material of claim 1 or 2, wherein comprises a combination of Co, Mn, Fe, Al and Y.

4. the material has an integrated peak width in a differential capacity plot (dQ) / (dV) of at least 25 mV between 4.1 and 4.25 V at the second charge cycle at a 0.2 C rate; 第２充電 IPW ４．１Ｖ～４．２５Ｖ 4. The particulate material according to claim 1, having

5. 5. A method for producing a particulate material according to any one of claims 1 to 4, comprising the steps of: (a) providing a particulate lithium nickelate; (b) The obtained lithium nickel oxide is treated with M １ or a solution of one or two of the compounds of １ and mixing the resulting mixture with a particulate oxide or hydroxide of the formula (I). (c) removing the solvent from step (b), if applicable; (d) heat treating the solid obtained from step (b) or (c), respectively; A method comprising:

6. 6. The method of claim 5, wherein step (d) is carried out at a maximum temperature in the range of 500 to 750°C.

7. 7. The process of claim 5 or 6, wherein step (c) comprises removing the solvent by a solid-liquid separation process.

8. 8. The method according to claim 5, wherein at least one solution in step (b) further contains a compound of Ni.

9. The lithium nickel oxide is M １ 7. The method according to claim 5 or 6, wherein the nanoparticulate oxide or hydroxide of

10. 10. The method of claim 5, 6 or 9, wherein in step (b) nickel oxide or hydroxide, which may be in the form of nanoparticles, is added.

11. (A) at least one cathode active material according to claim 1 ; (B) carbon in a conductive state; (C) at least one binder; a cathode.

12. 12. An electrochemical cell comprising the cathode of claim 11.

13. (A) at least one cathode according to claim 11; (B) at least one anode; and (C) at least one electrolyte Including batteries.

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