Method for manufacturing electrode active material

Abstract

1. A method for producing an electrode active material, the method comprising the steps of: (a) providing an (oxy)hydroxide or oxide of TM, wherein TM is a combination of metals, TM containing Ni and at least one of Mn and Co; (b) reacting the oxide or (oxy)hydroxide from step (a) with M 2 with a non-aqueous or aqueous solution of a compound of M 2 is selected from Ti, Zr, Nb or Ta; (c) removing the solvent(s), thereby obtaining a solid residue; (d) mixing the solid residue from step (c) with a lithium source, and optionally at least one compound of Ti, Al or Zr; (e) heat treating the mixture obtained from step (d) at a temperature in the range of 550 to 900°C; Includes.

Description

[Technical Field]

[0001] The present invention involves the following steps: (a) A step of providing an (oxy)hydroxide or oxide of TM, wherein TM is nickel or a combination of metals, and TM contains Ni and at least one of Mn and Co. (b) The oxide or (oxy) hydroxide from step (a) is M 2 A step of treating with a non-aqueous solution or aqueous solution of the compound, M 2 A process in which the material is selected from Ti, Zr, Nb, or Ta, (c) A step of removing the solvent(s) to obtain a solid residue, (d) A step of mixing the solid residue from step (c) with a lithium source and optionally at least one compound of Ti, Al, or Zr, (e) A step of heat-treating the mixture obtained from step (d) at a temperature in the range of 550 to 900°C, The present invention relates to a method for producing an electrode active material, which includes [a specific component]. [Background technology]

[0002] Lithium-ion rechargeable batteries are state-of-the-art devices for energy storage. Many applications have been considered, from small devices such as mobile phones and laptop computers to car batteries and other e-mobility batteries. Various battery components, such as electrolytes, electrode materials, and separators, play crucial roles in battery performance. Cathode materials, in particular, have received attention. Several materials have been proposed, such as lithium iron phosphate, lithium cobalt oxide, and lithium nickel cobalt manganese oxide. While extensive research has been conducted, the solutions found so far still have room for improvement.

[0003] The electrode material is extremely important for the characteristics of lithium-ion batteries. Lithium-containing mixed transition metal oxides, such as spinel or layered mixed oxides, particularly lithium-containing mixed oxides of nickel, manganese, and cobalt, are of particular importance (see, for example, EP 1 189 296). However, not only the stoichiometry of the electrode material, but also other characteristics such as morphology and surface properties are important.

[0004] In a typical manufacturing method of a cathode material for a lithium-ion battery, first, a so-called precursor is formed by co-precipitating a transition metal as a carbonate, oxide, or preferably a hydroxide, which may or may not be basic, such as an oxyhydroxide. Next, this precursor is mixed with a lithium salt, such as LiOH, Li2O, or Li2CO3 (not limited thereto), and fired (calcined) at a high temperature. The lithium salt(s) can be used as a hydrate(s) or in a dehydrated form. The firing or calcination, often also called the heat treatment or thermal treatment of the precursor, is usually carried out at a temperature in the range of from 600 to 1000 °C. During the heat treatment, a solid-state reaction occurs to form the electrode active material. The heat treatment is carried out in the heating zone of an oven or a kiln.

[0005] Existing lithium-ion batteries have room for improvement, particularly with regard to energy density and cycle stability. The low cycle stability is often due to side reactions on the surface of the cathode active material (CAM), but coatings that can reduce the side reactions have been found to be resistant to Li + cations. Therefore, an object of the present invention was to provide a cathode active material that overcomes the above drawbacks, and a method for manufacturing the same. + A typical type of cathode active material that realizes a high energy density contains a large amount of Ni, for example, at least 80 mol% with respect to the content of non-lithium metals (Ni-rich). However, the energy density still needs to be improved.

[0006]

Prior Art Documents

Patent Documents

[0007] [Patent Document 1] EP 1 189 296 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] Therefore, the object of the present invention was to provide a precursor for an electrode active material having a high energy density and a simple method for producing the same. [Means for solving the problem]

[0009] Therefore, the method defined at the beginning, also referred to below as "the method of the present invention," was found. The method of the present invention consists of the following steps: (a) A step of providing an (oxy)hydroxide or oxide of TM, wherein TM is nickel or a combination of metals, and TM contains Ni and at least one of Mn and Co. (b) The oxide or (oxy) hydroxide from step (a) is M 2 A step of treating with a non-aqueous solution or aqueous solution of the compound, M 2 A process in which the material is selected from Ti, Zr, Nb, or Ta, (c) A step of removing the solvent(s) to obtain a solid residue, (d) A step of mixing the solid residue from step (c) with a lithium source and optionally at least one compound of Ti, Al, or Zr, (e) A step of heat-treating the mixture obtained from step (d) at a temperature in the range of 550 to 900°C, Includes. [Brief explanation of the drawing]

[0010] [Figure 1]Figure 1 shows CAM.2. Left image: High-angle annular dark-field imaging (HAADF-STEM) of CAM.2. The arrow points to the crystallite surface. Right image: The arrow points to the layer of Nb oxide compound (bright color) concentrated on the crystallite surface (TEM-EDXS mapping). [Figure 2] Figure 2 shows CAM.3. Left image: High-angle annular dark-field imaging (HAADF-STEM) of CAM.3. The arrow points to the crystallite surface. Right image: The arrow points to the layer of concentrated Ta oxide compound (bright color) on the crystallite surface (TEM-EDXS mapping). [Figure 3] Figure 3 shows CAM.4. Left image: High-angle annular dark-field imaging (HAADF-STEM) of CAM.4. The arrow points to the crystallite surface. Right image: The arrow points to the layer of Nb oxide compound (bright color) concentrated on the crystallite surface (TEM-EDXS mapping). [Modes for carrying out the invention]

[0011] The method of the present invention comprises five steps (a), (b), (c), (d), and (e), which are also referred to as steps (a), (b), (c), (d), and (e) in the context of the present invention, respectively. Optionally, the method of the present invention further comprises step (e) or (f), or both, as described below. Steps (a) through (d), and any steps (e) and (f) are described in more detail below.

[0012] The method of the present invention starts with an (oxy)hydroxide or oxide of TM. In such an (oxy)hydroxide or oxide of TM, TM is a combination of at least two metals, containing Ni and at least one of Mn and Co. Preferably, TM contains Ni and both Co and Mn.

[0013] In one embodiment of the present invention, TM is of general formula (I) (Ni a Co b Mnc ) 1-d M d (I) (where a ranges from 0.6 to 0.99, b ranges from 0 or 0.01 to 0.2, c ranges from 0 to 0.2, d ranges from 0 to 0.1, M is at least one of Al, Mg, Ti, Mo, and W, b + c > 0, a + b + c = 1) is a combination of metals according to

[0014] The (oxy)hydroxide or oxide of the TM provided in step (a) preferably consists of spherical particles having a spherical shape. The spherical particles include not only particles that are exactly spherical but also particles in which the difference between the maximum diameter and the minimum diameter of at least 90% (number average) of a representative sample is 10% or less.

[0015] In one embodiment of the present invention, the (oxy)hydroxide or oxide of the TM provided in step (a) is composed of secondary particles that are aggregates of primary particles. Preferably, the (oxy)hydroxide or oxide of the TM provided in step (a) is composed of spherical secondary particles that are aggregates of primary particles. Even more preferably, the (oxy)hydroxide or oxide of the TM provided in step (a) is composed of spherical secondary particles that are aggregates of spherical primary particles or platelets.

[0016] In one embodiment of the present invention, the (oxy)hydroxide or oxide of the TM provided in step (a) has an average particle size (D50) in the range of 3 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 usually consist of aggregates from primary particles, and the above particle size refers to the particle size of the secondary particles.

[0017] Some elements are ubiquitous. In the context of this invention, trace amounts of ubiquitous metals such as sodium, calcium, iron, or zinc as impurities are not considered in the specification of this invention. In this context, "trace amount" means an amount of 0.02 mol% or less of the total metal content of TM.

[0018] The (oxy)hydroxide or oxide of TM provided in step (a) may contain trace amounts of anions other than oxides and hydroxides, such as carbonates and sulfates. In particular, when the (oxy)hydroxide or oxide of TM is produced from the sulfate of TM, some residual sulfate may remain in the precipitate. Carbonates may be included by using aged alkaline hydroxyls or by exposing newly precipitated TM(OH)2 to CO2-containing air.

[0019] The (oxy)hydroxide or oxide of TM provided in step (a) may be produced by coprecipitation of Ni, at least one of Co and Mn, and optionally further metals as the hydroxide of TM from an aqueous solution of nickel sulfate combined with an alkali metal hydroxide, which is a compound of cobalt or manganese sulfate or both, and optionally one or more metals selected from Al, Ti, Zr, V, Co, Zn, or Ba, followed by filtration and drying.

[0020] The (oxy)hydroxide of TM provided in step (a) can be produced by heating such hydroxide, for example, under vacuum or air, at a temperature in the range of 80 to 150°C, thereby removing water. The oxyhydroxide of TM means that it contains water chemically bonded as hydroxide, or a non-stoichiometric oxyhydroxide having a residual water content. In one embodiment of the present invention, the oxyhydroxide of TM has a water content in the range of 50 to 2000 ppm by mass. In this case, the water content includes chemically and physically bonded water and can be determined by Karl Fischer titration.

[0021] The (oxy)hydroxide or oxide of TM provided in step (a) is dried at a temperature in the range of 100 to 500°C to obtain an oxide or oxyhydroxide of TM having a water content in the range of 50 to 2000 ppm. In particular, if TM contains a large amount of manganese, partial oxidation of TM, especially manganese, occurs, and the oxide is not strictly a stoichiometric TMO.

[0022] The residual water content can be determined, for example, by Karl Fischer titration.

[0023] In step (b), the oxide or (oxy)hydroxide from step (a) is M 2 The compound is treated with a non-aqueous solution or aqueous solution, where M 2 is selected from Ti, Zr, Nb, or Ta, preferably M 2 is Nb or Ta, and more preferably M 2 This is Nb. Combinations of two or more of the above types are also usable.

[0024] This kind of M 2 The compound is M 2 From nitrates, sulfates, oxalates, such as Zr(SO4)2, ZrOSO4, ZrO(NO3)2, NH4)Nb(C2O4)3, (NH4)Ta(C2O4)3, (NH4)NbO(C2O4)2, (NH4)TaO(C2O4)2, or the corresponding hydrates, preferably M 2 C1-C4 alkanolates, such as metanolate, ethanolate, isopropanolate, n-propanolate, n-butanolate, isobutanolate, sec.-butanolate, tert-butanolate, and M 2 A mixture of C1-C4 alkanolates may be selected. Non-limiting examples include Ti(OC2H5)4, Zr(OC2H5)4, Ti(O-isoC3H7)4, Zr(O-isoC3H7)4, Nb(OC2H5)5, Ta(OC2H5)5, Nb(O-isoC3H7)5, Ta(O-isoC3H7)5, Nb(O-nC4H9)5, and Ta(O-nC4H9)5. A combination of at least two of the above compounds is also usable.

[0025] This kind of M 2 Suitable solvents for the compound are water and non-aqueous solvents such as alcohols and ethers, selected from diethyl ether, di-n-butyl ether, di-isopropyl ether, 1,4-dioxane, tetrahydrofuran (THF), methanol, ethanol, iso-propanol, n-butanol, and mixtures of at least two of the above. Water and C1-C4 alkanolates are preferred. 2 The preferred solvent for the C1-C4 alkanolates is the corresponding alcohol.

[0026] Step (b) involves adding the (oxy) hydroxide or oxide of TM to the M 2 By combining it with a solution of the compound, for example, the M 2 This may be done by adding a solution of the compound to the (oxy)hydroxide or oxide of TM, or vice versa.

[0027] In one embodiment of the present invention, M 2 The molar ratio of TM is in the range of 1:100 to 1:1000.

[0028] In one embodiment of the present invention, the M 2 The volume ratio of the solution to the (oxy) hydroxide or oxide of TM is in the range of 1:20 to 10:1.

[0029] Step (b) may be supported by a mixing operation, such as stirring or shaking.

[0030] In one embodiment of the present invention, step (b) is carried out at a temperature in the range of 5°C to 100°C, preferably 10 to 40°C, and more preferably at room temperature.

[0031] In one embodiment of the present invention, step (b) is carried out in air or in an atmosphere of nitrogen or a noble gas.

[0032] In one embodiment of the present invention, step (b) is initiated with a solvent selected from C1-C4 alkanolates, and water is added during step (b), for example by carrying out step (b) in a humid air or humid nitrogen atmosphere, or by adding liquid water.

[0033] In one embodiment of the present invention, step (b) is carried out under a pressure of 0.1 bar to 100 bar, preferably 0.5 bar to 10 bar.

[0034] In one embodiment of the present invention, step (b) has a duration of 1 minute to 2 hours, preferably 2 minutes to 30 minutes.

[0035] In step (c), the solvent(s)

[0036] In one embodiment of the present invention, the removal is preferred with respect to the organic solvent(s) used in step (b), and more preferably the complete or near-complete removal of such solvent. In this context, “nearly complete” means at least 95% by volume, preferably at least 98% by volume, of the organic solvent(s) used in step (b). More preferably, 98.5 to 99.9% by volume of the organic solvent(s) used in step (b) is removed.

[0037] In embodiments where water is the solvent or multiple solvents, it is preferable to remove at least 50%, preferably at least 75%, of the water, if applicable.

[0038] In one embodiment of the present invention, step (c) is carried out by evaporation at a temperature in the range of 10 to 150°C.

[0039] In one embodiment of the present invention, step (c) is carried out by evaporation at a pressure in the range of 10 to 500 millibars.

[0040] In one embodiment of the present invention, step (c) is carried out, for example, by filtering with a band filter or filter press at room temperature.

[0041] By performing step (c), a solid residue is obtained.

[0042] Step (d) includes mixing the solid residue from step (c) with a lithium source and optionally at least one compound of Ti, Al, or Zr.

[0043] Examples of lithium sources include inorganic lithium compounds such as LiNO3, Li2O, LiOH, Li2CO3, and combinations of at least two of the above, with Li2O, LiOH, and Li2CO3 being preferred, crystallizing water being negligible in the context of lithium sources, and LiOH being even more preferred.

[0044] In one embodiment of the present invention, the lithium source has an average particle size (D50) in the range of 1 to 5 μm.

[0045] Suitable aluminum compounds include, for example, Al(NO3)3, Al2O3, Al(OH)3, AlOOH, and Al2O3·aq, with AlOOH and Al2O3, particularly γ-Al2O3, being preferred. The aluminum source can be added as an aqueous solution, an aqueous slurry, or in particulate form, with particulate form being preferred.

[0046] In one embodiment of the present invention, the Al compound is particulate and has an average crystallite size determined by X-ray diffraction in the range of 2 nm to 20 nm, preferably 5 nm to 15 nm. The average particle size (D50) determined by dynamic laser scattering (DLS) is in the range of 1 to 10 μm, preferably 1 to 3 μm.

[0047] Suitable Ti compounds are TiO(OH)2, TiO(OH)4, TiO2, and TiO2·aq, with TiO2 being preferred.

[0048] In one embodiment of the present invention, the Ti compound is particulate and has an average crystallite size determined by X-ray diffraction in the range of 2 nm to 20 nm, preferably 5 nm to 15 nm. The average particle size (D50) determined by dynamic laser scattering (DLS) is in the range of 1 to 10 μm, preferably 1 to 3 μm.

[0049] Suitable Zr compounds are Li2ZrO3, ZrO(OH)2, Zr(OH)4, ZrO2, and ZrO2·aq, with Zr(OH)4, ZrO2, and ZrO2·aq being preferred, and Zr(OH)4 being even more preferred.

[0050] In one embodiment of the present invention, the Zr compound is particulate and has an average crystallite size determined by X-ray diffraction in the range of 2 nm to 20 nm, preferably 5 nm to 15 nm. The average particle size (D50) determined by dynamic laser scattering (DLS) is in the range of 1 to 10 μm, preferably 1 to 3 μm.

[0051] In one embodiment of the present invention, the molar ratio of the lithium source to (TM+Ti+Zr+Al) added in step (c) is in the range of 1.05:1 to 1.0:1.

[0052] In process (b), M 2 In embodiments in which Ti or Zr is selected, it is preferable not to add a Ti or Zr compound in step (d), respectively.

[0053] In one embodiment of the present invention, the molar amount of Al added in step (d) is in the range of 0.2 to 3 mol% relative to TM. In another embodiment, as described above, no Al compound is added in step (d).

[0054] In one embodiment of the present invention, the molar amount of Ti added in step (d) is in the range of 0.05 to 1 mol% relative to TM. In another embodiment, as described above, no Ti compound is added in step (d).

[0055] In one embodiment of the present invention, the molar amount of Zr added in step (d) is in the range of 0.05 to 1 mol% relative to TM. In another embodiment, as described above, no Zr compound is added in step (d).

[0056] Step (d) may be carried out as a single operation, but it is preferable that step (d) includes a sub-step of mixing the residue from step (c) with the lithium source, and then a sub-step of adding a solution of the magnesium source. The sub-steps are described in more detail below. However, it is preferable that step (d) be carried out in one step, or that the lithium source is first mixed with a magnesium or aluminum compound and a Ti or Zr compound (sub-step (d1)), and then the resulting mixture is combined with an oxide or oxyhydroxide of TM (sub-step (d2)). In other embodiments, the oxide or oxyhydroxide of TM is mixed with the lithium source, the magnesium or aluminum compound and the Ti or Zr compound in a single step.

[0057] Examples of suitable apparatus for carrying out process (d) include high-shear mixers, tumbler mixers, plow shear mixers, and free-fall mixers.

[0058] Step (d) may be carried out at a temperature in the range of 0 to 100°C, with room temperature being preferred.

[0059] In one embodiment of the present invention, step (d) has a duration of 10 minutes to 2 hours. Depending on whether additional mixing is performed in step (d), thorough mixing must be achieved in step (d).

[0060] In step (d), it is possible to add an organic solvent, such as glycerol or glycol, or water, but it is preferable to carry out step (d) in a dry state, i.e., without adding water or an organic solvent.

[0061] A mixture is obtained from step (d).

[0062] Step (e) includes heat-treating the mixture obtained from step (d) at a temperature in the range of 550 to 900°C.

[0063] Step (e) includes subjecting the mixture to heat treatment at a temperature in the range of, for example, 550 to 900°C, preferably 600 to 850°C, and more preferably 650 to 825°C.

[0064] In one embodiment of the present invention, the mixture from step (e) is heated to 650 to 850°C at a heating rate of 0.1 to 10°C / min.

[0065] In one embodiment of the present invention, the temperature is raised before reaching a desired temperature of 650 to 850°C, preferably 650 to 825°C. For example, the mixture from step (d) is first heated to 350 to 550°C, then held at a constant temperature for 10 minutes to 4 hours, and then raised to 650 to 850°C.

[0066] In embodiments in which at least one solvent is used in step (d), such solvent(s) are removed, either as part of or separately from step (d), before starting step (e), by, for example, filtration, evaporation, or distillation of such solvent(s). Evaporation and distillation are preferred.

[0067] In one embodiment of the present invention, step (e) 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.

[0068] In one embodiment of the present invention, step (e) is carried out in an oxygen-containing atmosphere, for example in pure oxygen or oxygen-enriched air, for example in a mixture of air and oxygen in a volume ratio of 1:3 to 1:10, with pure oxygen being preferred.

[0069] By performing the method of the present invention, a cathode active material exhibiting excellent stability, such as low capacity loss and high cycle stability, can be produced.

[0070] Further aspects of the present invention relate to a cathode active material, also referred to below as the cathode active material of the present invention.

[0071] General formula Li 1+x (M 2 y TM 1-y ) (1-x) The particulate cathode active material with O2 contains secondary particles which are aggregates of primary particles, where TM is nickel, or TM contains Ni and at least one of Mn and Co, x is in the range of 0 to 0.2, y is in the range of 0.001 to 0.01, and M 2 However, selected from Nb and Ta, they are concentrated on the crystallite surface of the primary particles, or otherwise uniformly distributed within such cathode active materials.

[0072] The aforementioned phrase, "otherwise...distributed uniformly," is M 2 This means that the cathode active material of the present invention is not concentrated on the outer surface of the secondary particles.

[0073] In one embodiment of the present invention, M 2 The compound concentrates on the crystallite surface of primary particles in the form of a layer with an average thickness of 2-30 nm. This compound may contain multiple compounds. Such M concentrates on the crystallite surface of primary particles. 2 The compounds (singular or plural) are Nb2O5, Ta2O5, ZrO2, TiO2, LiNbO3, LiTaO3, Li2ZrO3, Li4Ti5O 12 Selected from Li2TiO3. Nb2O5 and Ta2O5 are preferred.

[0074] In one embodiment of the present invention, TM is of general formula (I) (Ni a Co b Mn c) 1-d M 1 d (I) (In the formula, a is in the range of 0.6 to 0.99, b is 0 or in the range of 0.01 to 0.2. c is in the range of 0 to 0.2. d is in the range of 0 to 0.1. M 1 is at least one of Al, Mg, Ti, Mo, and W. (a + b + c = 1) This is a combination of metals. Preferably, b+c>0. Some elements are ubiquitous. In the context of this invention, trace amounts of ubiquitous metals such as sodium, calcium, iron, or zinc as impurities are not considered in the specification of this invention. In this context, "trace amount" means an amount of 0.02 mol% or less of the total metal content of TM.

[0075] In one embodiment of the present invention, the electrode active material of the present invention has an average particle size (D50) in the range of 3 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 aggregates of primary particles, and the above particle size refers to the particle size of the secondary particles.

[0076] In one embodiment of the present invention, the electrode active material of the present invention has a particle size distribution span defined by span = ((D90)-D(10)) / D(50) in the range of 0.3 to 1.5, preferably 0.3 to 0.5 or 0.8 to 1.2. The particle size distribution can be determined, for example, by light scattering, laser diffraction, or electroacoustic spectroscopy. The particles are usually composed of aggregates of primary particles, and the above particle size refers to the particle size of secondary particles.

[0077] In one embodiment of the present invention, the precursor of the present invention is 2 to 200 m 2 / g, preferably 2-50m 2It has a specific surface area (BET) determined by nitrogen adsorption in the range of / g, for example, in accordance with DIN-ISO 9277:2003-05.

[0078] A further aspect of the present invention relates to a cathode, which is also hereinafter referred to as the cathode of the present invention.

[0079] In particular, the cathode of the present invention (A) at least one electrode active material of the present invention, (B) carbon in a conductive state, (C) a binder or a binder material, also referred to as binder (C), and preferably (D) a current collector contains.

[0080] In a preferred embodiment, the cathode of the present invention is based on the total of (A), (B) and (C) (A) 80 to 98% by mass of the electrode active material of the present invention, (B) 1 to 17% by mass of carbon, (C) 1 to 15% by mass of the binder material contains.

[0081] The cathode according to the present invention can include further components. They can include a current collector, such as, but not limited to, an aluminum foil. They can further include conductive carbon and a binder.

[0082] The cathode according to the present invention contains carbon (B), which is also simply referred to as carbon, for conductive modification. Carbon (B) can be selected from soot, activated carbon, carbon nanotubes, graphene, and graphite, and combinations of at least two of the above.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] Another preferred binder (C) is polybutadiene.

[0089] Other suitable binders (C) are selected from polyethylene oxide (PEO), cellulose, carboxymethylcellulose, polyimide, and polyvinyl alcohol.

[0090] 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.

[0091] The binder (C) may be a crosslinked or uncrosslinked (co)polymer.

[0092] 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.

[0093] Suitable binders (C) include, in particular, polyvinyl alcohol and halogenated (co)polymers, such as polyvinyl chloride or polyvinylidene chloride, and especially fluorinated (co)polymers, such as polyvinyl fluoride and especially polyvinylidene fluoride and polytetrafluoroethylene.

[0094] 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 another embodiment, the cathode of the present invention may contain 0.1 to less than 1% by mass of a binder (one or more).

[0095] A further aspect of the present invention is a battery comprising at least one cathode, at least one anode, and at least one electrolyte, each comprising the electrode active material, carbon, and binder of the present invention.

[0096] Embodiments of the cathode of the present invention have already been described in detail above.

[0097] 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.

[0098] The electrolyte may include at least one non-aqueous solvent, at least one electrolyte salt, and optionally an additive.

[0099] 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.

[0100] Examples of suitable polymers include, in particular, polyalkylene glycols, preferably poly-C1-C4 alkylene glycols, and especially 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.

[0101] A suitable polyalkylene glycol, particularly a polyethylene glycol, has a molecular weight M W It can be at least 400 g / mol.

[0102] 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.

[0103] 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.

[0104] Suitable examples of cyclic ethers are tetrahydrofuran and 1,4-dioxane.

[0105] Suitable examples of acyclic acetals include, for example, dimethoxymethane, diethoxymethane, 1,1-dimethoxyethane, and 1,1-diethoxyethane.

[0106] Suitable examples of cyclic acetals are 1,3-dioxane and, in particular, 1,3-dioxolane.

[0107] Suitable examples of acyclic organic carbonates include dimethyl carbonate, ethyl methyl carbonate, and diethyl carbonate.

[0108] 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.)

[0109] In a particularly preferred embodiment, R 1 is methyl, and R 2 and R 3 Each is either hydrogen or R 1 , R 2 and R 3 Each of these is hydrogen.

[0110] Another preferred cyclic organic carbonate is the vinylene carbonate of formula (IV).

[0111] [ka]

[0112] 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.

[0113] 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)

[0114] 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.

[0115] In one embodiment 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 metallic lithium, particularly porous polymer films. Particularly preferred materials for the separators are polyolefins, particularly film-forming porous polyethylene and film-forming porous polypropylene.

[0116] 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.

[0117] 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.

[0118] The battery according to the present invention may further include a housing that can have any shape, for example, a cube, or the shape of a cylindrical disk or cylindrical can. In one modified embodiment, a metal foil configured as a pouch is used as the housing.

[0119] The battery according to the present invention exhibits good discharge behavior, very good discharge and cycle behavior, for example, at low temperatures (0°C or below, for example, -10°C or lower).

[0120] 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.

[0121] 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.

[0122] The present invention will be further explained by the following embodiments. [Examples]

[0123] The average particle size (D50) was determined by dynamic light scattering ("DLS"). Percentages are expressed in mass percent unless otherwise specified.

[0124] TEM analysis: Sample material Epofix resin (Struers, Copenhagen, The samples were embedded in Denmark. Ultrathin samples (~100 nm) for transmission electron microscopy (TEM) were prepared by ultrafine fabrication and transferred to a TEM sample carrier grid. The samples were imaged by TEM using Tecnai Osiris and Themis Z3.1 instruments (Thermo-Fisher, Waltham, USA) operated at 200 / 300 keV under HAADF-STEM conditions. Chemical composition maps were obtained by energy-dispersive X-ray spectroscopy (EDXS) using a SuperX G2 detector. Images and elemental maps were evaluated using Velox (Thermo-Fisher) and Esprit (Bruker, Billerica, USA) software packages.

[0125] Ultrafine machining typically slices secondary particles along the grain boundaries of primary particles, rather than creating a cross-section of the primary particles. EDS determines the integrated chemical composition across the entire thickness of the sample. The signals of coating elements in the inner region of the primary crystal are due to the surface coatings on the top and bottom of the particles.

[0126] Step (a.1): Using ammonia as a complexing agent, a 1.65 mol / kg solution of nickel sulfate was combined with a 25% by mass solution of NaOH to obtain spherical Ni(OH)2 precursors. The pH value was set to 12.6. The newly precipitated Ni(OH)2 was washed with water, sieved, and dried at 120°C for 12 hours. Then, the newly precipitated Ni(OH)2 was poured into an alumina crucible and dried in an oxygen atmosphere (10 exchanges / h) at 500°C in a furnace at a heating rate of 3°C / min and a cooling rate of 10°C / min for 3 hours to obtain precursor p-CAM.1 having a D50 of 6 μm.

[0127] Manufacturing of comparative cathode active material C-CAM.1: The dehydrated precursor p-CAM.1 was mixed with LiOH·H2O in a Li:Ni molar ratio of 1.01:1, poured into an alumina crucible, and heated at 350°C for 4 hours and then at 700°C for 6 hours under an oxygen atmosphere (10 changes / h) at 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 using a 30 μm mesh size to obtain a comparative material C-CAM.1 having a D50 of 6 μm.

[0128] Manufacturing of the material CAM.2 of the present invention: Step (b.2): Under a nitrogen atmosphere, 40 g of precursor p-CAM.1 was placed in a beaker. 2.84 g of niobium(V) ethoxide was dissolved in 10 ml of dry ethanol. The resulting solution was added dropwise to the beaker through a dropping funnel over 5 minutes at room temperature until the precursor was submerged in the liquid. No visible liquid film formed on the precursor. The resulting slurry was stirred in the beaker for 30 minutes. The individual amounts of Nb and Ni were set so that the Ni:Nb molar ratio was 0.98:0.02.

[0129] Step (c.2): The slurry was then heated at 120°C and a pressure of 10 millibars for 6 hours to remove the ethanol and obtain p-CAM.2.

[0130] Steps (d.2) and (e.2): The precursor p-CAM.2 was mixed with LiOH·H2O in a molar ratio of 1.01:1 Li:(Ni+Nb), poured into an alumina crucible, and heated at 350°C for 4 hours and 700°C for 6 hours under an oxygen atmosphere (10 changes / h) with a heating rate of 3°C / min and a 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.2 of the present invention.

[0131] Manufacturing of the material CAM.3 of the present invention: Step (b.3): Under a nitrogen atmosphere, 40 g of precursor p-CAM.1 was placed in a beaker. 3.67 g of tantalum(V) ethoxide was dissolved in 10 ml of dry ethanol. The resulting solution was added dropwise to the beaker through a dropping funnel over 5 minutes at room temperature until the precursor was submerged in the liquid. No visible liquid film formed on the precursor. The resulting slurry was stirred in the beaker for 30 minutes. The individual amounts of Ta and Ni were set so that the Ni:Ta molar ratio was 0.98:0.02.

[0132] Step (c.3): The slurry was then heated at 120°C and a pressure of 10 millibars for 6 hours to remove the ethanol and obtain p-CAM.3.

[0133] Steps (d.3) and (e.3): The precursor p-CAM.3 was mixed with LiOH·H2O in a molar ratio of 1.01:1 Li:(Ni+Ta), poured into an alumina crucible, and heated at 350°C for 4 hours and 700°C for 6 hours under an oxygen atmosphere (10 changes / h) with a heating rate of 3°C / min and a cooling rate of 10°C / min. The material thus obtained was then sieved using a 30 μm mesh size to obtain the cathode active material CAM.3 of the present invention.

[0134] Step (a.4): Using ammonia as a complexing agent, spherical precursors with a molar composition of Ni:Co:Mn = 91:4.5:4.5 were obtained by combining aqueous sulfate solutions of each transition metal in the corresponding ratio (1.65 mol / kg solution) with a 25 mass% NaOH aqueous solution. The pH value was set to 11.7. The newly precipitated material was washed with water, sieved, and dried at 120°C for 12 hours. Then, the material was poured into an alumina crucible and dried in an oxygen atmosphere (10 exchanges / h) at 500°C in a furnace at a heating rate of 3°C / min and a cooling rate of 10°C / min for 3 hours to obtain precursor p-CAM.4 having a D50 of 11 μm.

[0135] Manufacturing of the material CAM.4 of the present invention: Step (b.4): Under a nitrogen atmosphere, 50 g of precursor p-CAM.4 was placed in a beaker. 3.42 g of niobium(V) ethoxide was dissolved in 10 g of dry ethanol. The resulting solution was added dropwise to the beaker through a dropping funnel over 5 minutes at room temperature until the precursor was submerged in the liquid. No visible liquid film formed on the precursor. The resulting slurry was stirred in the beaker for 1-2 minutes. The individual amounts of Nb and (Ni:Co:Mn) were set so that the (Ni:Co:Mn):Nb molar ratio was 0.98:0.02.

[0136] Step (c.4): The slurry was then heated at room temperature and under vacuum for 24 hours, and then the ethanol was removed by heating at 60°C and a pressure of 10 millibars for 72 hours to obtain p-CAM.5.

[0137] Steps (d.4) and (e.4): Precursor p-CAM.5 was mixed with LiOH·H2O, Al2O3, ZrO2, and TiO2 in a molar ratio of 1.04:1 for Li:(Ni+Co+Mn+Nb) and a (Ni+Co+Mn+Nb):Al:Zr:Ti ratio of 0.974:0.02:0.003:0.003. The mixture was poured into an alumina crucible and heated at 750°C for 6 hours under an oxygen atmosphere (10 changes / h) with a heating rate of 3°C / min and a cooling rate of 10°C / min. The material thus obtained was then sieved using a 32 μm mesh size to obtain the cathode active material CAM.4.

[0138] As shown by HAADF and EDS mapping, in CAM.2 and CAM.4, niobium oxide was found to be concentrated on the crystallite surface of the primary particles, or otherwise uniformly distributed within such cathode active material. As shown by HAADF and EDS mapping, in CAM.3, tantalum oxide was found to be concentrated on the crystallite surface of the primary particles, or otherwise uniformly distributed within such cathode active material.

[0139] Manufacturing of comparative material C-CAM.5: Steps (d.5) and (e.5): Precursor p-CAM.4 was mixed with LiOH·H2O, Al2O3, ZrO2, and TiO2 in a Li:(Ni+Co+Mn) molar ratio of 1.04:1 and a (Ni+Co+Mn):Al:Zr:Ti ratio of 0.974:0.02:0.003:0.003. The mixture was poured into an alumina crucible and heated at 750°C for 6 hours under an oxygen atmosphere (10 changes / h) with a heating rate of 3°C / min and a cooling rate of 10°C / min. The material thus obtained was then sieved using a 32 μm mesh size to obtain the cathode active material C-CAM.5.

[0140] Electrode Manufacturing: The electrodes contained 94% of each CAM or C-CAM, 3% carbon black (Super C65), and 3% binder (polyvinylidene fluoride, Solef 5130). The slurry was mixed in N-methyl-2-pyrrolidone and cast onto aluminum foil with a doctor blade. After drying in vacuum at 105°C for 6 hours, circular electrodes were punched out, weighed, and dried in vacuum at 120°C for 12 hours before being placed in a glove box filled with Ar.

[0141] Half-cell electrochemical measurement: A coin-type electrochemical cell ("coin half-cell") was assembled in an argon-filled glove box. A 14 mm diameter positive electrode (with a load of 8.0 ± 0.5 mg cm²) was used. -2The electrodes were separated from the 0.58mm thick Li foil by a glass fiber separator (Whatman GF / D). 95 μl of 1 M LiPF6 in ethylene carbonate (EC):ethyl methyl carbonate (EMC) in a mass ratio of 3:7 was used as the electrolyte. The cells were cycled at constant current between 3.1 and 4.3 V at room temperature using a Maccor 4000 battery cycler until 70% of the initial discharge capacity was reached in a given discharge step by applying the following C rates.

[0142] [Table 1]

[0143] After charging at the above C rate, all charging steps except the first charging step are replaced with a constant voltage step (CV). * The test was terminated after 1 hour, or until the current reached 0.02C.

[0144] During cycling, data points were collected every minute, or after a voltage change of at least 5 mV occurred. For each material, four electrochemical cells were assembled, and the corresponding cycle profiles, capacitance, and resistance were obtained by averaging the four cells.

[0145] During the resistance measurement (performed every 25 cycles at 25°C), the cell was charged at 0.2C until it reached 50% of its previous discharge capacity. A 30-minute open-circuit step followed to balance the cell. Finally, a discharge current of 2.5C was applied for 30 seconds, and the resistance was measured. After the current pulse ended, the cell was again balanced in an open circuit for 30 minutes and then discharged further at 0.2C to 3.0V.

[0146] To calculate the resistance, we obtained the voltage V0s before applying the 2.5C pulse current, the voltage V30s after applying the 2.5C pulse current for 30 seconds, and the 2.5C current value (j, expressed in A). The resistance was calculated according to Equation 3 (V: voltage, j: 2.5C pulse current).

[0147] R=(V0s-V30s) / j (formula 1)

[0148] [Table 2]

[0149] CAM.4 exhibits superior electrochemical properties compared to C-CAM.5.

Claims

1. The following steps: (a) A step of providing an (oxy) hydroxide or oxide of TM, wherein TM is Ni or a combination of metals containing Ni and at least one of Mn and Co, (b) The oxide or (oxy) hydroxide from step (a) is M ２ A step of treating with a non-aqueous solution or aqueous solution of the compound, M ２ The process involves selecting from Ti, Zr, Nb, or Ta, and selecting the compound of M2 from C1-C4-alkanolates. (c) A step of removing the solvent(s) to obtain a solid residue, (d) A step of mixing the solid residue from step (c) with a lithium source and optionally at least one compound of Ti, Al, or Zr, (e) A step of heat-treating the mixture obtained from step (d) at a temperature in the range of 550 to 900°C, A method for producing an electrode active material containing [the specified element].

2. TM is general formula (I) (N ａ Co ｂ Mn ｃ ) １－ｄ M ｄ (I) (In the formula, a is in the range of 0.6 to 0.99, b is 0 or in the range of 0.01 to 0.

2. c is in the range of 0 to 0.

2. d is in the range of 0 to 0.

1. M is at least one of Al, Mg, Ti, Mo, and W. b + c > 0, a + b + c = 1) The method according to claim 1, wherein the combination of metals is as follows.

3. The method according to claim 1 or 2, wherein the (oxy)hydroxide provided in step (a) has a water content in the range of 50 to 2000 ppm by mass.

4. M ２ The method according to any one of claims 1 to 3, wherein is selected from Nb and Ta.

5. The method according to any one of claims 1 to 4, wherein step (c) is carried out by evaporation of one or more solvents.

6. The solvent in step (b) is selected from water and C １ ~C ４ -alkanols, and the method according to any one of claims 1 to 5.

7. M ２ The method according to any one of claims 1 to 6, wherein the molar ratio of to TM is in the range of 1:100 to 1:1000.

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