Electrode active material and method for producing the same

Abstract

1. A method for producing a particulate lithiated transition metal oxide, comprising the steps of: (a) providing a particulate transition metal precursor comprising Ni; (b) mixing the precursor with at least one lithium compound and at least one processing additive selected from NaCl, KCl, CuCl2, BO, MoO3, Bi2O3, NaSO4 and KSO4 in an amount of 0.1 to 5% by weight based on the total mixture obtained in step (b); (c) In at least two stages: (c1) In an atmosphere containing oxygen, at 300 to 500°C, (c2) In an oxygen atmosphere, at 650 to 850°C, heat treating the mixture obtained according to step (b); Includes.

Description

[Technical Field]

[0001] The present invention involves the following steps: (a) A step of providing a particulate transition metal precursor containing Ni, (b) The precursor is (b1) at least one lithium compound, and (b2) Before or after step (c1), add 0.1 to 5% by mass, preferably 0.5 to 5% by mass, of at least one treatment additive selected from NaCl, KCl, CuCl2, B2O3, MoO3, Bi2O3, Na2SO4 and K2SO4, relative to the total amount of the precursor and lithium compound. The mixing process, (c) At least two stages: (c1) Under an atmosphere that can contain oxygen, at 300-500°C, (c2) Under an oxygen atmosphere, at 650-850°C, A step of heat-treating the mixture obtained according to step (b) and This invention relates to a method for producing particulate lithium-ionized transition metal oxides, including those mentioned above. [Background technology]

[0002] Lithium transition metal oxides are currently 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 that negatively impact the lifespan or applicability of lithium-ion batteries, such as reduced cycle life and capacity loss. Further efforts are being made to improve manufacturing methods.

[0003] In a typical method for producing cathode materials for lithium-ion batteries, a so-called precursor is first formed by coprecipitation of a transition metal as a carbonate, oxide, or preferably as a hydroxide, such as an oxyhydroxide, which may be basic or not. Next, this precursor is mixed with a lithium source, such as LiOH, Li2O, or Li2CO3 (but not limited to these), and calcined at a high temperature. The lithium salt(s) can be used as a hydrate(s) or in a dehydrated form. Calcination or calcination, often also called heat treatment or heating of the precursor, is usually carried out at temperatures in the range of 600 to 1,000°C. During the heat treatment, a solid-phase reaction occurs to form the electrode active material. The heat treatment is carried out in the heating zone of an oven or kiln.

[0004] Typical types of cathode active materials that provide high energy density contain a large amount of Ni (Ni-rich), such as at least 80 mol% Ni relative to the content of non-lithium metals. However, in this case, the cycle life is limited due to some instability issues of the cathode in the charged state. The main cause of degradation in batteries containing Ni-rich cathode materials is the mechanical breakdown of particles due to large volume changes during delithiation. The breakdown of primary and secondary particles in the battery can be effectively investigated in real time by acoustic emission, a highly sensitive technique that detects sound waves emitted from the broken particles. [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] Therefore, an object of the present invention is to provide a cathode active material having high cycle stability, which is detected to show no significant particle breakdown during cycling and is therefore a promising candidate for improved cycle stability. Furthermore, an object of the present invention was to provide a method for producing a cathode active material having high cycle stability. [Means for solving the problem]

[0006] Thus, the method defined at the beginning, also referred to below as the method of the present invention or the method according to the present invention, has been found. Hereinafter, the method of the present invention will be described in more detail.

Embodiments for Carrying out the Invention

[0007] The method of the present invention includes the following steps (a), (b) and (c), also referred to below as step (a), step (b) and step (c) respectively, or briefly as (a) or (b) or (c).

[0008] In step (a), a particulate precursor containing nickel is provided. The precursor containing nickel may be selected from carbonates, oxides, hydroxides and oxyhydroxides. Preferably, such a particulate precursor is a hydroxide or oxyhydroxide of TM, where at least 80 mol% of TM is nickel.

[0009] In one embodiment of the present invention, the particulate precursor contains nickel, at least one metal selected from Co and Mn, and optionally at least one further metal selected from Ti, Zr, Mo, W, Al, Mg, Nb and Ta. Preferably, at least 80 mol% of the metal content of the precursor is nickel.

[0010] The precursor may contain trace amounts of further metal ions, such as ubiquitous metals such as trace amounts of sodium, calcium or zinc, as impurities, but such trace amounts are not considered in the context of the present invention. Trace amounts in this context mean amounts of 0.05 mol% or less relative to the total metal content of the precursor.

[0011] In one embodiment of the present invention, the particulate transition metal precursor is selected from hydroxides, carbonates, oxyhydroxides and oxides of TM, where TM has the general formula (I), (Ni a Co b Mn c ) 1-d M d (I) (In the formula, a is in the range of 0.8 to 0.95, preferably in the range of 0.85 to 0.91) b is in the range of 0 to 0.1, preferably in the range of 0 to 0.05. c is in the range of zero to 0.1, preferably in the range of 0.02 to 0.05. d is in the range of zero to 0.1. M is selected from Mg, Al, Ti, Zr, Mo, W, Al, Nb, and Ta. At least one of variables b and c is greater than zero. (a + b + c = 1) It is a combination of metals.

[0012] The precursor is particulate. In one embodiment of the present invention, the average particle size (D50) of the precursor is in the range of 4 to 15 μm, preferably 6 to 15 μm, and more preferably 7 to 12 μm. In the context of the present invention, the average particle size (D50) refers to the average value of the volume-based particle size, which can be determined, for example, by light scattering, and refers to the particle size of secondary particles.

[0013] In one embodiment of the present invention, the particle shape of the precursor secondary particles deviates from an ideal spherical shape and is more similar to, for example, a potato. In one embodiment of the present invention, the aspect ratio of the secondary particles is in the range of 1.2 to 3.5, preferably 1.8 to 2.8.

[0014] In one embodiment of the present invention, the specific surface area (BET) of the precursor is determined by nitrogen adsorption according to DIN-ISO 9277:2003-05, and is 1 to 10 m 2 / g, preferably 2-10m 2 It is within the range of / g.

[0015] In one embodiment of the present invention, the precursor may have a particle size distribution span in the range of 0.5 to 0.9, which is defined as [(D90)-(D10)] divided by (D50), and is determined entirely by laser analysis. In another embodiment of the present invention, the precursor may have a particle size distribution span in the range of 1.1 to 1.8.

[0016] In step (b1), the obtained precursor is mixed with a lithium compound, which is also referred to below as the "lithium source".

[0017] Examples of lithium sources include Li2O, LiNO3, LiOH, Li2O2, Li2CO3, their anhydrous or hydrated forms, and, where applicable, LiOH·H2O. LiOH, Li2O, and Li2O2 are preferred. A more preferred lithium source is lithium hydroxide.

[0018] Such lithium sources are preferably in the form of parts, for example, having an average particle size (D50) in the range of 3 to 10 μm, preferably 5 to 9 μm.

[0019] In one embodiment of the present invention, the amount of lithium compound is selected such that the molar ratio of lithium to the molar metal content of the precursor is in the range of 1:1 to 1.1:1, preferably 1.02:1 to 1.05:1.

[0020] In step (b2), at least one treatment additive selected from NaCl, KCl, CuCl2, B2O3, MoO3, Bi2O3, Na2SO4, and K2SO4 is added in an amount of 0.1 to 5% by mass, preferably 0.5 to 5% by mass, relative to the total amount of the precursor and the lithium compound. MoO3, NaCl, KCl, and mixtures of at least two of them, such as a eutectic mixture of NaCl and KCl, are preferred.

[0021] In one embodiment of the present invention, the processing additive has an average particle size (D50) in the range of 1 to 50 μm, preferably 2 to 10 μm.

[0022] The order in which the precursor, lithium source, and processing additive are added is not important. In one embodiment of the present invention, the lithium compound and processing additive are first mixed, and then added to the precursor. In such an embodiment, steps (b1) and (b2) are performed simultaneously.

[0023] In another embodiment of the present invention, step (b1) is performed first, then step (b2), and then the resulting mixture is subjected to step (c1).

[0024] In another embodiment of the present invention, step (b2) is performed after step (c1).

[0025] In one embodiment of the present invention, the amount of the processing additive is in the range of 0.05 to 5% by mass, preferably 0.1 to 2.5% by mass, relative to the total amount of the precursor and the lithium compound.

[0026] Suitable examples of apparatus for carrying out process (b) include tumbler mixers, high-shear mixers, plow shear mixers, and free-fall mixers. On a laboratory scale, a mortar and pestle with a pestle and a ball mill can also be used.

[0027] In one embodiment of the present invention, the mixing in step (b) is carried out over a period of 1 minute to 10 hours, preferably 5 minutes to 1 hour.

[0028] In one embodiment of the present invention, the mixing in step (b) is carried out without external heating.

[0029] In one embodiment of the present invention, no dopant is added in step (b).

[0030] In a particular embodiment of the present invention, in step (b), an oxide, hydroxide, or oxyhydroxide of Mg, Al, Ti, Zr, Mo, W, Co, Mn, Al, Nb, and Ta, or a combination of at least two of the above, preferably Al, Ti, Zr, or W, is added, also referred to below as a dopant.

[0031] Such dopants are selected from oxides, hydroxides and oxyhydroxides of Mg, Ti, Zr, Mo, W, Co, Mn, Nb, and Ta, and especially Al. Lithium titanate is also a usable titanium source. Examples of dopants include TiO2 (preferably anatase) selected from rutile and anatase, further basic titania such as TiO2·aq and TiO(OH)2, and further Li4Ti5O 12 , basic zirconia such as ZrO2, Zr(OH)4, ZrO2·aq, Li2ZrO3, and ZrO(OH)2, and further CoO, Co3O4, Co(OH)2, MnO, Mn2O3, Mn3O4, MnO2, Mn(OH)2, MoO2, MoO3, MgO, Mg(OH)2, Mg(NO3)2, Ta2O5, Nb2O5, Nb2O3, and further WO3, Li2WO4, Al(OH)3, Al2O3, Al2O3·aq, and AlOOH. Al compounds such as Al(OH)3, α-Al2O3, γ-Al2O3, Al2O3·aq, and AlOOH are preferred. Even more preferred dopants are Al2O3 selected from α-Al2O3 and γ-Al2O3, with γ-Al2O3 being most preferred.

[0032] In one embodiment of the present invention, such dopants have a specific surface area (BET) in the range of 1 to 200 m 2 / g, preferably 50 to 150 m 2 / g. The specific surface area (BET) can be determined by nitrogen adsorption, for example, in accordance with DIN-ISO 9277:2003-05.

[0033] In one embodiment of the present invention, such dopants are nanocrystals. Preferably, the average crystallite diameter of the dopants is at most 100 nm, preferably at most 50 nm, and even more preferably at most 15 nm. The minimum diameter may be 4 nm.

[0034] In one embodiment of the present invention, such dopants (one or more) are particulate materials having an average particle size (D50) in the range of 1 to 10 μm, preferably 2 to 4 μm. The dopants (one or more) are usually in the form of aggregates. The particle size refers to the diameter of the aggregates.

[0035] In a preferred embodiment, the dopant(s)

[0036] In step (b), it is possible to add an organic solvent, such as glycerol or glycol, or water and mix it in a ball mill, but it is preferable to carry out step (b) in a dry state, i.e., without adding water or an organic solvent.

[0037] A mixture is obtained from step (b).

[0038] Step (c) is performed at at least two different temperatures. (c1) In an atmosphere that can contain oxygen, at 300-500°C, preferably 400-485°C, and (c2) Under an oxygen atmosphere, at 650-850°C, preferably 700-825°C, This includes subjecting the mixture from step (b) to heat treatment.

[0039] In a preferred embodiment of the present invention, step (c1) is carried out at a temperature in the range of 400°C to 485°C, and step (c2) is carried out at a temperature in the range of 725°C to 825°C.

[0040] The oxygen atmosphere in step (c2) may be pure oxygen, or a small amount of non-oxidizing gas, such as oxygen diluted with 5% by volume of nitrogen or argon, as determined under normal conditions.

[0041] The atmosphere in step (c1) may be oxidizing, for example, air, or a mixture of air and a non-oxidizing gas such as nitrogen or argon. The atmosphere in step (c1) is preferably oxidizing. More preferably, the atmosphere in step (c1) is pure oxygen.

[0042] Steps (c1) and (c2) may be carried out in different containers, but it is preferable to carry them out in the same container and change the temperature, preferably the atmosphere, when transitioning from step (c1) to step (c2).

[0043] In one embodiment of the present invention, step (c) is carried out in a roller hearth kiln, a pusher kiln, or a rotary kiln, or a combination of at least two of the above. The rotary kiln has the advantage of providing very good homogenization of the material produced therein. In roller hearth kilns and pusher kilns, different reaction conditions for different steps can be set very easily. In laboratory-scale experiments, box furnaces, tubular furnaces, and segmented tubular furnaces can also be used.

[0044] In one embodiment of the present invention, step (c) is carried out under a forced flow of a gas, such as air, oxygen, or oxygen-enriched air. Such a gas flow is sometimes called a forced gas flow. Such a gas flow is generally given by Li 1+x TM 1-x 0.5-15 m for electrode active material with O2 3 It can have a specific flow velocity in the range of / (h·kg). The volume is determined under normal conditions (298 Kelvin and 1 atmosphere). The forced flow of the gas is useful for removing gaseous decomposition products such as water.

[0045] In one embodiment of the present invention, step (c) has a duration ranging from 2 to 30 hours, preferably 10 to 24 hours. In this context, the cooling time is negligible.

[0046] In one embodiment of the present invention, step (c1) has a duration in the range of 1 to 15 hours. 3 to 10 hours is preferred.

[0047] In one embodiment of the present invention, step (c2) has a duration ranging from 1 to 15 hours, preferably 5 to 12 hours. In this context, the cooling time is negligible.

[0048] After heat treatment according to step (c), the electrode active material thus obtained is cooled before further processing. An additional (optional) step before further processing of the obtained electrode active material is a sieving and de-aggregation step.

[0049] The method of the present invention yields an electrode active material that has particularly excellent properties with respect to crack resistance and cycle stability.

[0050] In one embodiment of the present invention, after step (c), the electrode active material is washed with alcohol, such as ethanol or methanol, or with water, then filtered and dried. The washing may be supported by stirring or a ball mill.

[0051] Further aspects of the present invention relate to an electrode active material, also referred to below as the electrode active material or cathode active material of the present invention. The cathode active material of the present invention can be synthesized according to the method of the present invention. The electrode active material of the present invention will be described in more detail below.

[0052] The electrode active material of the present invention is in particulate form, and its general formula is Li 1+x TM 1-x Corresponding to O2, where TM is a combination of Ni and at least one transition metal selected from Co and Mn, and optionally at least one further metal selected from Ti, Zr, Mo, W, Al, Mg, Nb and Ta, x is in the range of 0 to 0.2, the average particle size (D50) of its primary particles is in the range of 2 to 15 μm, and the acoustic activity in the frequency range of 350 to 700 kHz is less than 150 cumulative hits / cycle during the first cycle. In this regard, an acoustic signal is considered a hit if at least two counts exceeding 27 dB are recorded.

[0053] The electrode active material of the present invention is particulate. In one embodiment of the present invention, the average particle size (D50) of the electrode active material of the present invention is in the range of 2 to 15 μm, preferably 5 to 10 μm. In the context of the present invention, the average particle size (D50) refers to the average value of the volume-based particle size, which can be determined, for example, by light scattering, and refers to the particle size of secondary particles.

[0054] In one embodiment of the present invention, the particle shape of the precursor secondary particles deviates from an ideal spherical shape and is more similar to, for example, a potato. In one embodiment of the present invention, the aspect ratio of the secondary particles is in the range of 1.2 to 3.5, preferably 1.8 to 2.8.

[0055] In one embodiment of the present invention, the specific surface area (BET) of the electrode active material of the present invention is determined by nitrogen adsorption, for example, according to DIN-ISO 9277:2003-05, and is 0.1 to 1.5 m². 2 It is within the range of / g.

[0056] In one embodiment of the present invention, the electrode active material of the present invention may have a particle size distribution span in the range of 0.5 to 0.9, which is defined as [(D90)-(D10)] divided by (D50), and is determined entirely by laser analysis. In another embodiment of the present invention, the electrode active material of the present invention may have a particle size distribution span in the range of 1.1 to 1.8.

[0057] In one embodiment of the present invention, the secondary particles of the electrode active material of the present invention consist of an average of 2 to 35 primary particles, as determined by evaluation using a scanning electron microscope (SEM).

[0058] Further aspects of the present invention relate to electrodes comprising at least one electrode active material of the present invention. These are particularly useful in lithium-ion batteries. Lithium-ion batteries comprising at least one electrode according to the present invention exhibit good cycle behavior / stability. Electrodes comprising at least one electrode active material of the present invention are hereinafter also referred to as cathodes of the present invention or cathodes according to the present invention.

[0059] In particular, the cathode of the present invention is (A) At least one electrode active material of the present invention, (B) Conductive carbon, (C) Binder material, also called binder or binder(C), and preferably (D) Current collector It contains.

[0060] In a preferred embodiment, the cathode of the present invention is based on the sum of (A), (B), and (C), (A) 80-98% by mass of the electrode active material of the present invention, (B) 1-17% by mass of carbon, (C) Binder material in 1-15% by mass It contains.

[0061] The cathode according to the present invention may include further components, which may include current collectors, such as aluminum foil (but not limited to this). They may further include conductive carbon and a binder.

[0062] The cathode according to the present invention contains conductively modified carbon, also abbreviated as carbon(B). Carbon(B) can be selected from soot, activated carbon, carbon nanotubes, graphene, graphite, and at least two combinations thereof.

[0063] A suitable binder (C) is preferably selected from organic (co)polymers. Suitable (co)polymers, i.e., homopolymers or copolymers, can be selected from (co)polymers that can be obtained by anionic (co)polymerization, catalytic (co)polymerization or free radical (co)polymerization, particularly from copolymers of polyethylene, polyacrylonitrile, polybutadiene, polystyrene, and at least two comonomers selected from ethylene, propylene, styrene, (meth)acrylonitrile, and 1,3-butadiene. Polypropylene is also suitable. Polyisoprene and polyacrylate are even more suitable. Polyacrylonitrile is particularly preferred.

[0064] 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. Polyacrylonitrile homopolymers are preferred.

[0065] In the context of the present invention, polyethylene means not only homopolyethylene but also at least 50 mol% copolymerized ethylene and 50 mol% or less of at least one further comonomer, such as α-olefins, such as propylene, butylene (1-butene), 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-pentene, and also isobutene, vinyl aromatics, such as styrene, and also (meth)acrylic acid, vinyl acetate, vinyl propionate, and C1-C of (meth)acrylic acid. 10 -Alkyl esters, particularly methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-butyl acrylate, 2-ethylhexyl acrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate, and copolymers of ethylene containing maleic acid, maleic anhydride, and itaconic anhydride. Polyethylene may be HDPE or LDPE.

[0066] In the context of the present invention, polypropylene is understood to mean not only homopolypropylene but also copolymers of propylene comprising at least 50 mol% copolymerized propylene and at least one further comonomer of 50 mol% or less, such as ethylene, and α-olefins, such as butylene, 1-hexene, 1-octene, 1-decene, 1-dodecene, and 1-pentene. Polypropylene is preferably isotactic polypropylene or essentially isotactic polypropylene.

[0067] In the context of the present invention, polystyrene refers not only to styrene homopolymers, but also to acrylonitrile, 1,3-butadiene, (meth)acrylic acid, and C1-C of (meth)acrylic acid.10 -It is understood to also refer to copolymers with alkyl esters, divinylbenzene, particularly 1,3-divinylbenzene, 1,2-diphenylethylene, and α-methylstyrene.

[0068] Another preferred binder (C) is polybutadiene.

[0069] Other suitable binders (C) are selected from polyethylene oxide (PEO), cellulose, carboxymethylcellulose, polyimide, and polyvinyl alcohol.

[0070] In one embodiment of the present invention, the binder (C) has an average molecular weight M in the range of 50,000 g / mol to 1,000,000 g / mol, preferably up to 500,000 g / mol. W Selected from (co)polymers having the following properties.

[0071] The binder (C) may be a crosslinked or uncrosslinked (co)polymer.

[0072] In particularly preferred embodiments of the present invention, the binder (C) is selected from halogenated (co)polymers, particularly fluorinated (co)polymers. Halogenated or fluorinated (co)polymers are understood to mean (co)polymers comprising 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.

[0073] Suitable binders (C) include polyvinyl alcohol and halogenated (co)polymers, such as polyvinyl chloride or polyvinylidene chloride, particularly fluorinated (co)polymers, such as polyvinyl fluoride and especially polyvinylidene fluoride, and polytetrafluoroethylene.

[0074] The cathode of the present invention may contain 1 to 15% by mass of a binder (one or more) relative to the electrode active material. In other embodiments, the cathode of the present invention may contain 0.1 to less than 1% by mass of a binder (one or more).

[0075] A further aspect of the present invention is a battery comprising at least one cathode containing the electrode active material of the present invention, carbon, and a binder, at least one anode, and at least one electrolyte.

[0076] Embodiments of the cathode of the present invention are as described in detail above.

[0077] The anode may contain at least one anode active material, such as carbon (graphite), TiO2, lithium titanium oxide, silicon, or tin. The anode may further contain a current collector, such as a metal foil, such as copper foil.

[0078] The electrolyte may include at least one non-aqueous solvent, at least one electrolyte salt, and optionally an additive.

[0079] The non-aqueous solvent for the electrolyte may 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.

[0080] Examples of suitable polymers include, in particular, polyalkylene glycols, preferably poly-C1-C4 alkylene glycols and polyethylene glycols. Here, polyethylene glycol may contain 20 mol% or less of one or more C1-C4 alkylene glycols. The polyalkylene glycol is preferably a polyalkylene glycol having two methyl or ethyl terminal caps.

[0081] A suitable polyalkylene glycol, particularly a polyethylene glycol, has a molecular weight M W It can be at least 400 g / mol.

[0082] A suitable polyalkylene glycol, particularly a polyethylene glycol, has a molecular weight M W This can be up to 5,000,000 g / mol, preferably up to 2,000,000 g / mol.

[0083] Examples of suitable acyclic ethers include, for example, diisopropyl ether, di-n-butyl ether, 1,2-dimethoxyethane, and 1,2-diethoxyethane, with 1,2-dimethoxyethane being preferred.

[0084] Suitable examples of cyclic ethers are tetrahydrofuran and 1,4-dioxane.

[0085] Suitable examples of acyclic acetals include, for example, dimethoxymethane, diethoxymethane, 1,1-dimethoxyethane, and 1,1-diethoxyethane.

[0086] Suitable examples of cyclic acetals are 1,3-dioxane and, in particular, 1,3-dioxolane.

[0087] Suitable examples of acyclic organic carbonates include dimethyl carbonate, ethyl methyl carbonate, and diethyl carbonate.

[0088] Suitable examples of cyclic organic carbonates are compounds of general formulas (II) and (III). [ka] (In the formula, R 1 , R 2 and R 3 These can be the same or different, and are selected from hydrogen and C1-C4 alkyl groups, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl and tert-butyl, preferably R 2 and R 3 (Neither of them can be tert-butyl.)

[0089] In a particularly preferred embodiment, R 1 is methyl, and R 2 and R 3 Each of them is either hydrogen or R 1 , R 2 and R 3 Each of these is hydrogen.

[0090] Another preferred cyclic organic carbonate is the vinylene carbonate of formula (IV). [ka]

[0091] Preferably, the solvent or a plurality of solvents are used in a water-free state, i.e., with a water content in the range of 1 ppm to 0.1% by mass, which can be determined, for example, by Karl Fischer titration.

[0092] The electrolyte (C) further comprises at least one electrolyte salt. Preferred electrolyte salts are lithium salts in particular. Examples of preferred lithium salts are LiPF6, LiBF4, LiClO4, LiAsF6, LiCF3SO3, and 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 in the range of 1 to 20), LiN(SO2F)2, Li2SiF6, LiSbF6, LiAlCl4, and the general formula (C n F 2n+1 SO2) t YLi salt (In the formula, when Y is selected from oxygen and sulfur, t=1, When Y is selected from nitrogen and phosphorus, t=2, (If Y is selected from carbon and silicon, then t=3)

[0093] Preferred electrolyte salts are selected from LiC(CF3SO2)3, LiN(CF3SO2)2, LiPF6, LiBF4, and LiClO4, with LiPF6 and LiN(CF3SO2)2 being particularly preferred.

[0094] In embodiments of the present invention, the battery according to the present invention includes one or more separators by which electrodes are mechanically separated. Preferred separators are polymer films that do not react with lithium metal, particularly porous polymer films. Particularly preferred materials for the separators are polyolefins, particularly porous polyethylene and porous polypropylene for film formation.

[0095] Separators made of polyolefins, particularly polyethylene or polypropylene, can have a porosity in the range of 35-45%. Suitable pore sizes are, for example, in the range of 30-500 nm.

[0096] In another embodiment of the present invention, the separator can be selected from a PET nonwoven fabric filled with inorganic particles. Such a separator may have a porosity in the range of 40-55%. A suitable pore size is, for example, in the range of 80-750 nm.

[0097] The battery according to the present invention further includes a housing which can have any shape, for example, a cube, or the shape of a cylindrical disk or a cylindrical can. In one modified embodiment, a metal foil configured as a pouch is used as the housing.

[0098] The battery according to the present invention exhibits good discharge behavior, and very good discharge and cycle behavior, for example, at low temperatures (below 0°C, even below -10°C).

[0099] The battery according to the present invention may include two or more electrochemical cells that are combined with each other, for example, connected in series or in parallel. 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 cell contains cathode according to the present invention. Even more preferably, in the battery according to the present invention, all electrochemical cells contain cathode according to the present invention.

[0100] The present invention further provides a method for using the battery according to the present invention in equipment, in particular mobile equipment. Examples of mobile equipment include vehicles, such as automobiles, bicycles, aircraft, or watercraft, such as boats or ships. Other examples of mobile equipment include manually operated devices, such as computers, in particular laptops, telephones, or power tools in the construction sector, such as drills, battery-powered screwdrivers, or battery-powered staplers.

[0101] The present invention will be further explained by the following embodiments. [Examples]

[0102] Overview: rpm: revolutions per minute I. Production of the electrode active material of the present invention I.1 Manufacturing process of precursor TM-OH.1 (a.1) An aqueous solution of ammonium sulfate at a concentration of 49 g per 1 kg of water was placed in a stirred tank reactor. The solution was heated to 55°C, and the pH was adjusted to 12 by adding an aqueous sodium hydroxide solution.

[0103] The coprecipitation reaction was initiated by simultaneously supplying aqueous solutions of transition metal sulfates and sodium hydroxide at a flow rate ratio of 1.8, with a total flow rate of 8 hours. The transition metal solution contained sulfates of Ni, Co, and Mn in a molar ratio of 8.3:1.2:0.5 and a total transition metal concentration of 1.65 mol / kg. The sodium hydroxide solution contained a 25% by mass sodium hydroxide solution and a 25% by mass ammonia solution at a mass ratio of 6. The pH value was maintained at 12 by supplying an additional sodium hydroxide solution. Starting from the initiation of all supplies, the mother liquor was continuously collected. After 33 hours, all supply flows were stopped. The resulting suspension was filtered, washed with distilled water, dried in air at 120°C, and sieved to obtain the mixed transition metal (TM) oxyhydroxide precursor TM-OH.1. Average particle size (D50): 10 μm.

[0104] I.2 Production of Cathode Active Material I.2.1 Preparation of mixtures, (b.1) Using a planetary mixer, the precursor TM-OH.1 was mixed with LiOH monohydrate at a Li / (Ni+Co+Mn) molar ratio of 1.02, and with a eutectic mixture of NaCl / KCl at 1% by mass relative to the total amount of lithium hydroxide and precursor (KCl / NaCl molar ratio of 1:1).

[0105] I.2.2 Firing In each case, the heating rate and cooling rate were 3°C / min.

[0106] Process (c1.1): The mixture obtained from I.2.1 was heated in a muffle furnace to 450°C over 6 hours in a dry air atmosphere. It was then cooled to ambient temperature. A pre-calcined mixture was obtained.

[0107] Process (c2.1): The pre-calcined mixture from process (c1.1) was heated in a muffle furnace to 750°C over 12 hours in a pure oxygen atmosphere. Cathode active material CAM.1 was obtained.

[0108] Next, CAM.1 was subjected to a ball mill at 60 rpm with ethanol (1 ml of ethanol per 1 g of CAM.1), and then filtered. It was dried in a vacuum at 100°C for 8 hours to obtain the finished CAM.1.

[0109] In the production of the comparative electrode active material C-CAM.2, the above procedure was repeated, but NaCl / KCl was not added.

[0110] II. Testing of Cathode Active Materials II.1 Electrode Manufacturing, General Procedure For the cathode, a PVDF binder (Solef® 5130) was dissolved in NMP (Merck) to prepare a 7.5% by mass solution. For electrode preparation, the binder solution (3% by mass) and carbon black (Super C65, 3% by mass) were suspended in NMP. After mixing using a planetary centrifugal mixer (ARE-250, Thinky Corp.; Japan), the CAM of the present invention (or comparative CAM) (94% by mass) was added, and the suspension was mixed again to obtain a lump-free slurry. The solid content of the slurry was adjusted to 61%. The slurry was coated onto Al foil using a KTF-S roll-to-roll coater (Mathis AG). Before use, all electrodes were calendered. The cathode material thickness was 100 μm, and the concentration was 6.5 mg / cm². 2 This was addressed. Before assembling the battery, all electrodes were dried at 105°C for 7 hours.

[0111] II.2 Electrolyte Preparation A base electrolyte composition (EL base 1) containing 1 M LiPF6 in ethylene carbonate and ethyl methyl carbonate in a mass ratio of 3:7 was prepared.

[0112] II.3 Manufacturing of Test Cells Coin-type half-cells (20 mm in diameter, 3.2 mm thick) containing the cathode prepared as described in II.1 and lithium metal as the working electrode and counter electrode were assembled and sealed in a glove box filled with Ar. Furthermore, half-coin cells were fabricated by stacking the cathode, anode, and separator in the order of cathode / / separator / / Li foil. Subsequently, 0.15 mL of EL base 1 as described in (II.2) above was introduced into these coin cells.

[0113] III. Evaluation of Cell Performance Evaluation of the performance of coin half-cells We evaluated the cell performance using the manufactured coin-type half-cell batteries. Battery performance was assessed by measuring the initial capacity and response resistance of the cells.

[0114] We recorded cycling data at 25°C using a battery cycler from MACCOR Inc. For the first 10 cycles, we used a 4.3V vs Li cell. + Charge to / Li with a constant current (galvanostatically), then perform constant potential charging for 15 minutes (or a shorter time if the charging current drops below C / 20), at a rate of C / 10 (1C = 225mA / g CAM ) 3.0V vs Li + The battery was discharged to / Li. For the following 100 cycles, the charge and discharge rates were set to C / 4 and C / 2 respectively, resulting in 4.3V vs Li. + The constant potential length at / Li was set to 10. The results are summarized in Table 1.

[0115] [Table 1]

[0116] Acoustic Emission Measurement Setup: The AE instrument consisted of a sensor, an inline preamplifier, and a data acquisition system (USB AE node, MISTRAS Group, Inc.). To detect characteristic AE events, a differential wideband sensor (MISTRAS Group, Inc.) with an operating frequency range of 125–1000 kHz was fixed to the cathode-side coin cell using silicone grease. To reduce background noise from the laboratory, the entire structure was placed in a high-density foam box. In all experiments, preamplifier gain, analog filter, a sampling rate of 40 dB, 20–1000 kHz, and 5 MSPS were used, respectively. AE was recorded when a hit exceeded a threshold of 27 dB. Furthermore, the peak definition time, hit definition time, and hit lockout time were set to 100, 200, and 200 μs, respectively. The recorded AE signals were processed using AEwin for USB software (MISTRAS Group, Inc.). Signals less than 2 counts or below 100 kHz were excluded. In calculating the hit rate, the accumulated (measured) time-dependent AE signal was interpolated to the acquisition time at 10-second intervals, differentiated, and smoothed using a quadratic polynomial and 20 points per window.

[0117] Measuring one electrochemical cycle of the CAM with the aforementioned setup, it was found that the acoustic activity in the frequency range of 350–700 kHz was 50 hits during the first cycle, i.e., it falls within the definition of a silent CAM.

Claims

1. The following steps: (a) providing a particulate transition metal precursor containing Ni, wherein the particulate precursor is a hydroxide or oxyhydroxide of TM and at least 80 mol% of TM is nickel; (b) the precursor is (b1) at least one lithium compound, and Before step (b2), at least one processing additive selected from NaCl, KCl, CuCl, B ２ O ３ , MoO ３ , Bi ２ O ３ , Na ２ SO ４ , K ２ SO ４ is added in an amount of 0.1 to 5% by mass based on the total of the precursor and the lithium compound. ２ , B ２ O ３ , MoO ３ , Bi ２ O ３ , Na ２ SO ４ and K ２ SO ４ is added to the mixture. mixing; (c) in at least two stages: (c1) at 300 to 500 °C in an atmosphere that is oxidizing and is air or a mixture of air and a non-oxidizing gas such as nitrogen or argon; (c2) at 650 to 850 °C in an atmosphere of pure oxygen or an atmosphere of oxygen diluted with up to 5 vol% of nitrogen or argon; heat-treating the mixture obtained according to step (b). A method for producing a particulate lithiated transition metal oxide, comprising:

2. wherein the lithium compound is Li ２ O, LiOH, Li ２ O ２ 、Li ２ CO ３ 、and LiHCO ３ selected from, the method according to claim 1.

3. The method according to claim 1 or 2, wherein the particulate mixed transition metal precursor contains nickel, at least one metal selected from Co and Mn, and optionally at least one further metal selected from Ti, Zr, Mo, W, Al, Mg, Nb and Ta.

4. The particulate transition metal precursor is selected from hydroxides, carbonates, oxyhydroxides and oxides of TM, and TM has the general formula (I), (Ni a Co b Mn c ) 1-d M d (I) (wherein a ranges from 0.8 to 0.95, b ranges from zero to 0.1, c ranges from zero to 0.1, d ranges from zero to 0.1, M is selected from Mg, Al, Ti, Zr, Mo, W, Al, Nb and Ta, at least one of the variables b and c is greater than zero, a + b + c = 1). The method according to any one of claims 1 to 3, which is a combination of metals according to

5. The method according to any one of claims 1 to 4, wherein step (c) is carried out in a roller hearth kiln, a rotary kiln, a pusher kiln, a vertical kiln or a pendulum kiln.

6. The method according to any one of claims 1 to 5, wherein the treatment additive has an average particle size (D50) in the range of 1 μm to 50 μm.

7. The method according to any one of claims 1 to 6, wherein the treatment additive in step (b) is added to the mixture during step (c2).

8. The method according to any one of claims 1 to 7, wherein step (c1) is carried out in air, oxygen-enriched air or an oxygen atmosphere.

9. General formula Li １＋ｘ TM １－ｘ O ２ (wherein, TM is a combination of Ni and at least one transition metal selected from Co and Mn, and optionally at least one further metal selected from Ti, Zr, Mo, W, Al, Mg, Nb and Ta, x ranges from zero to 0.2, and at least 80 mol of TM is nickel), a particulate electrode active material, wherein the average particle size (D50) of the primary particles ranges from 2 to 15 μm, and the acoustic activity in the frequency range of 350 to 700 kHz is 50 cumulative hits / cycle or more and less than 150 cumulative hits / cycle during the first cycle. A particulate electrode active material.

10. The particulate electrode active material according to claim 9, wherein the secondary particles are composed of an average of 2 to 35 primary particles.

11. The specific surface area (BET) is determined by nitrogen adsorption in accordance with DIN-ISO 9277:2003-05 and is in the range of 0.1 to 1.5 m ２ / g, for the particulate electrode active material according to claim 9 or 10.

12. (A) At least one cathode active material according to any one of Claims 9 to 11, (B) Carbon in a conductive state, (C) At least one binder A cathode comprising:

13. An electrochemical cell comprising the cathode according to Claim 12.