Method for producing (oxy)hydroxide, and (oxy)hydroxide

Abstract

1. A method for producing an (oxy)hydroxide of TM, wherein TM refers to a metal that is at least 97 mol % transition metal, wherein TM comprises manganese and nickel, and wherein at least 50 mol % of TM is manganese, said method comprising the steps of: (a) providing an aqueous solution (α) of at least one water-soluble salt of said metal, and an aqueous solution (β) comprising an alkali metal hydroxide selected from NaOH and KOH; (b) combining solutions (α) and (β) at a pH value in the range of 9.5 to 10.3 to precipitate TM (oxy)hydroxides, wherein step (b) is carried out using at least one coaxial mixer comprising two coaxially oriented pipes, by means of which the aqueous solutions (β) and (α) are introduced into a stirred vessel; (c) recovering and drying the TM (oxy)hydroxide; Includes.

Description

[Technical Field]

[0001] The present invention relates to a method for producing an (oxy)hydroxide of TM, wherein TM refers to a metal of which at least 97 mol % is a transition metal, TM includes manganese and nickel, and at least 50 mol % of TM is manganese, said method comprising the steps of: (a) providing an aqueous solution (α) of at least one water-soluble salt of such a metal, and an aqueous solution (β) comprising an alkali metal hydroxide selected from NaOH and KOH; (b) combining solutions (α) and (β) at a pH value in the range of 9.5 to 10.3 to precipitate TM (oxy)hydroxides, wherein step (b) is carried out using at least one coaxial mixer comprising two coaxially oriented pipes, by means of which the aqueous solutions (β) and (α) are introduced into a stirred vessel; (c) recovering and drying the TM (oxy)hydroxide; Includes. [Background technology]

[0002] Lithiated transition metal oxides are currently used as electrode active materials in lithium-ion batteries. Extensive research and development has been conducted over the past several years to improve properties such as charge density and specific energy, as well as other properties such as cycle life degradation and capacity loss that 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 hydroxide to form a so-called precursor. This precursor is then mixed with a lithium compound, such as, but not limited to, LiOH, Li2O, or especially Li2CO3, and calcined at high temperatures. The lithium compound(s) can be used as hydrate(s) or in dehydrated form. Calcination or calcination, also commonly referred to as thermal treatment or heat treatment of the precursor, is typically carried out at temperatures ranging from 600 to 1000°C. When hydroxides or carbonates are used as precursors, removal of water or carbon dioxide occurs first, followed by the lithiation reaction. Heat treatment is carried out in the heated zone of an oven or kiln.

[0005] Extensive research has been conducted to improve various properties of cathode active materials, such as energy density and charge / discharge performance, including capacity loss. However, many cathode active materials suffer from limited cycle life and voltage loss. This is especially true for many Mn-rich cathode active materials.

[0006] EP 3 486 980 discloses certain high manganese materials with high energy density retention, however the disclosed cathode active materials suffer from limited energy density by themselves.

[0007] However, high manganese materials have been observed to have low volumetric energy densities. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] EP 3 486 980 Summary of the Invention [Problem to be solved by the invention]

[0009] Therefore, it was an object of the present invention to provide an electrochemical cell having a high volumetric energy density. It was also an object of the present invention to provide a method for producing an electrode active material for an electrochemical cell having a high volumetric energy density. [Means for solving the problem]

[0010] It has been found that the volumetric energy density can be improved with spherical particles due to their superior packing characteristics compared to irregularly shaped particles.

[0011] It has been found that the precursor of the cathode active material plays an important role, and therefore a method for producing the (oxy)hydroxide defined at the outset has been found, hereinafter also referred to as "the method of the invention" and "the method according to the (present) invention". The method of the invention comprises steps (a), (b) and (c), hereinafter also referred to as step (a) or simply (a), step (b) or simply (b), and step (c) or simply (c). Steps (a) to (c) are described in more detail below. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 shows top-view SEM images, photographs (a) and (b), of the comparative precursor C-TM-OH.3, and top-view SEM images, photographs (c) and (d), of the inventive precursor TM-OH.1, and top-view SEM images, photographs (e) and (f), of TM-OH.2. [Figure 2] FIG. 2 shows cross-sectional SEM images of inventive precursors TM-OH.1(a) and TM-OH.2(b), and comparative precursor C-TM-OH.3(c). [Figure 3] FIG. 3 shows a cross-sectional SEM image of an exemplary inventive CAM.1. DETAILED DESCRIPTION OF THE INVENTION

[0013] The method of the present invention is a method for precipitating TM (oxy)hydroxides, where TM refers to a metal that is at least 97 mol % transition metal, including manganese and nickel, and where at least 50 mol %, preferably 60-85 mol %, of the TM is manganese. The TM may also include a non-transition metal, such as aluminum or magnesium. More preferably, the TM is a combination of manganese and nickel.

[0014] The (oxy)hydroxides may be stoichiometrically pure hydroxides or hydroxides with anions other than hydroxide, such as carbonates or oxides. Manganese, in particular, is easily oxidized in the presence of an oxidizing agent. Carbonates, in particular, are produced by adsorption of carbon dioxide by, for example, alkali metal hydroxides or their aqueous solutions.

[0015] In one embodiment of the present invention, TM corresponds to general formula (I): Ni a M 1 b Mn c (I) (In the formula, M 1 is at least one metal selected from Co, Ti, Zr, Nb, Ta, W, Sb, Sr, Al and Mg, a is a number in the range of 0.20 to 0.50, preferably 0.30 to 0.40, b is a number ranging from 0 to 0.05, preferably 0 or 0.02 to 0.04, c is a value in the range of 0.50 to 0.80, preferably 0.60 to 0.70, a+b+c=1.0).

[0016] In one embodiment of the present invention, the TM contains only Mn and Ni.

[0017] The TM may contain trace amounts of additional metal ions as impurities, such as trace amounts of ubiquitous metals such as sodium, iron, calcium, or zinc, but such trace amounts are not considered within 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 TM.

[0018] In one embodiment of the present invention, the resulting TM (oxy)hydroxide is particulate and has a unimodal particle size distribution. The particle size distribution can be determined by light scattering, laser diffraction, or electroacoustic spectroscopy, with laser diffraction being preferred. The average particle size (D50) is preferably in the range of 2 to 15 μm, e.g., 2 to 12 μm, and in a preferred embodiment, the average particle size D50 is in the range of 3 to 8 μm.

[0019] In step (a), an aqueous solution (α) of at least one water-soluble salt of such a metal and an aqueous solution (β) containing an alkali metal hydroxide selected from NaOH and KOH are provided. It is possible to provide two or more aqueous solutions (α), each containing one water-soluble salt. However, it is preferred to provide only one aqueous solution (α).

[0020] The term water-soluble salts of nickel or manganese, or of metals other than nickel and manganese, refers to salts that have a solubility in distilled water at 25°C of 25 g / l or more, the amount of salt being determined omitting water of crystallization and water resulting from aquo complexes. The water-soluble salts of nickel and manganese are preferably Ni 2+ and Mn 2+ Examples of water-soluble salts of nickel and manganese include sulfates, nitrates, acetates, and halides, particularly chlorides. Nitrates and sulfates are preferred, and sulfates are more preferred.

[0021] Said aqueous solution (α) preferably comprises the relative concentrations of Ni and Mn, and optionally further metal(s), intended as TM of the precursor. The solution(s) (α) can have a pH value ranging from 2 to 5. In embodiments where a higher pH value is desired, ammonia can be added to solution (α). However, it is preferred not to add ammonia to solution (α). In one embodiment of the invention, one solution (α) is provided that contains all the metals to be precipitated.

[0022] In step (a), an aqueous solution of an alkali metal hydroxide, hereinafter also referred to as solution (β), is further provided. Examples of alkali metal hydroxides are lithium hydroxide, preferably potassium hydroxide, and a combination of sodium hydroxide and potassium hydroxide, and even more preferably sodium hydroxide.

[0023] Solution (β) may contain small amounts of carbonate, for example 0.1 to 2% by mass relative to the amount of the respective alkali metal hydroxide, either added intentionally or by aging of the solution or the respective alkali metal hydroxide.

[0024] Solution (β) can have a hydroxide concentration ranging from 0.1 to 12 mol / l, preferably from 6 to 10 mol / l.

[0025] The pH value of the solution (β) is preferably 13 or higher, for example 14.5.

[0026] In the process of the present invention, ammonia is used, but is preferably fed separately as solution (γ) or solution (β), but not as solution (α).

[0027] Optionally, at least one complexing agent selected from ammonia, glycine, citrate and oxalate may be provided. Glycine, citrate and oxalate are preferably provided as sodium salts. The complexing agent may be contained in the aqueous solution (β) or in a separate aqueous solution (γ). However, it is more preferred to carry out the process of the present invention without the use of a complexing agent. The aqueous solution (γ) can contain ammonia in the range of 1 to 25% by mass.

[0028] The aqueous solution (γ) may contain glycine, citrate or oxalate as a salt, for example as a sodium salt, in the range of 0.1 to 5% by weight, the percentages in these cases being relative to the free acid.

[0029] In step (b) of the method of the present invention, aqueous solutions (α) and (β) are combined at a pH value in the range of 9.5 to 10.3, preferably 9.5 to 10.0, wherein step (b) is carried out using at least one coaxial mixer comprising two coaxially oriented pipes, through which aqueous solutions (β) and (α) are introduced into a stirred vessel. The pH values ​​refer to values ​​measured at 23°C.

[0030] During step (b), care is taken to ensure that a minimum pH value of 9.5 is achieved. Furthermore, care is taken to ensure that the pH value does not exceed 10.3 during step (b). Preferably, the pH value is kept constant in the range of 10.0 to 10.3, ±0.01. In the context of the present invention, a coaxial mixer comprises two coaxially arranged pipes through which the aqueous solutions (β) and (α) are introduced into a stirred vessel. In one embodiment of the present invention, the introducing step is carried out by using two or more coaxial mixers through which the aqueous solutions (β) and (α) are introduced into said stirred vessel. In another embodiment of the present invention, the introducing step is carried out by using exactly one system of coaxially arranged pipes through which the aqueous solutions (β) and (α) are introduced into said stirred vessel. In a preferred embodiment of the present invention, the aqueous solution (α) is introduced through the inner pipe of the coaxial mixer, and the aqueous solution (β) is introduced through the outer pipe, which minimizes the occurrence of deposits.

[0031] In one embodiment of the present invention, the inner tube of the coaxial mixer has an inner diameter in the range of 1 mm to 120 mm, preferably in the range of 5 mm to 50 mm, depending on the container size. The larger the container, the larger the diameter of the inlet tip.

[0032] In one embodiment of the present invention, the outer pipe of such a coaxial mixer has an inner diameter in the range of 1.5 to 10 times, preferably 1.5 to 6 times, the inner diameter of the inner pipe. The pipe preferably has a circular profile.

[0033] In one embodiment of the invention, the wall of the pipe has a thickness in the range of 1 to 10 mm. The pipe may be made from steel, stainless steel or steel coated with PTFE (polytetrafluoroethylene), FEP (fluorinated ethylene-propylene copolymer), PFA (perfluoroalkoxy polymer), with stainless steel being preferred.

[0034] In one embodiment of the present invention, the pipes of the coaxial mixer are bent. In a preferred embodiment of the present invention, the pipes of the coaxial mixer are not bent.

[0035] The coaxial mixer may function as a coaxial nozzle.

[0036] In one embodiment of the present invention, the aqueous solutions (α) and (β) are introduced at positions, for example, 3 to 50 cm above the liquid level. In a preferred embodiment of the present invention, the aqueous solution of a transition metal salt and the aqueous solution of an alkali metal hydroxide are introduced at positions, for example, 5 to 250 cm, preferably more than 10 cm to 200 cm below the liquid level.

[0037] If an aqueous solution (γ) is also introduced, such aqueous solution (γ) is also preferably introduced by means of a coaxial mixer.

[0038] In one embodiment of the present invention, step (b) is carried out at a temperature in the range of 5 to 75°C, preferably 35 to 70°C.

[0039] The pressure conditions for step (b) are generally not critical: step (b) may be carried out at atmospheric pressure or at a pressure slightly above atmospheric pressure, for example in the range of 5 mbar to 5 bar above atmospheric pressure. In one embodiment of the present invention, the residence time in step (b) ranges from 10 minutes to 12 hours.

[0040] Step (b) may be carried out continuously or as a batch process, hi one embodiment, step (b) is carried out as a batch process, and the mother liquor is removed (withdrawn) through a solid-liquid separation device, for example a clarifier, such as a lamellar clarifier.

[0041] In one embodiment of the invention, the vessel is a continuous stirred tank reactor, said continuous stirred tank reactor being advantageously equipped with devices for controlling the temperature and devices such as baffles, guide vanes, etc.

[0042] Step (b) is preferably carried out in the absence of an oxidizing agent such as oxygen, and therefore step (b) may be carried out under an inert atmosphere, for example under nitrogen or a noble gas such as argon.

[0043] Preferably, step (b) is carried out under mixing, for example stirring, hi one embodiment, a stirring energy input in the range of 2.0 to 25.0 W / l is introduced.

[0044] During step (b), a slurry of TM (oxy)hydroxide is formed. To increase the volume of the stirred reactor, mother liquor can be removed during step (b), for example, through a clarifier. Mother liquor in this context refers, for example, to water containing the respective alkali metal salt of the counterion of TM, if applicable, a complexing agent, and traces of alkali metal hydroxide.

[0045] After step (b), step (c) is carried out. (c) recovering and drying the TM (oxy)hydroxides.

[0046] Step (c) preferably comprises a solid-liquid separation step, for example using a centrifuge, or filtration, for example using a belt filter or filter press, by which a liquid phase ("mother liquor") is removed and particulate hydroxide is recovered.

[0047] The filtration step preferably includes one or more washing steps. The filter cake can be washed with water or an aqueous solution of NaOH or KOH, such as a diluted solution (β). A solid residue is obtained, and a mother liquor, such as a filtrate, is obtained.

[0048] After recovery of the TM (oxo)hydroxide, the resulting solid residue can be dried, for example, at a temperature ranging from 80 to 120°C. The drying can be carried out in vacuum, under an inert gas such as nitrogen, or in air. In embodiments in which the residue is dried under air, at least partial oxidation of the manganese can occur, converting some of the hydroxide to the oxide. Preferably, the majority of the manganese is converted to the +IV oxidation state. In one embodiment of the present invention, after step (b), sub-step (b+) is carried out, in which the slurry from step (b) is transferred to a second stirred vessel, in which it is combined with solutions (α) and (β) at a pH value in the range of 9.5 to 11.0 measured at 23°C, and step (b+) is carried out in a continuous process or a batch process or a semi-continuous process, thereby further growing the TM (oxy)hydroxide particles.

[0049] The temperature conditions and general definitions of solutions (α) and (β) are the same as in step (b) above.

[0050] In one embodiment of the present invention, step (b+) has a duration ranging from 1 hour to 10 hours.

[0051] Particulate hydroxides are obtained that are excellent precursors to cathode active materials. The precursors can be mixed with a lithium compound, e.g., LiOH, Li2CO3, or Li2O2, and optionally one or more additives such as Al2O3, TiO2, ZrO2, Zr(OH)4, or oxyhydroxides of Al, Ti, or Zr, and then heat-treated at temperatures ranging from 800 to 1000°C. The molar ratio Li:TM is preferably in the range of 1.05:1 to 1.5:1, preferably 1.25 to 1.4.

[0052] Another aspect of the present invention is directed to a precursor of a cathode active material for a lithium-ion battery, hereinafter also referred to as a precursor of the present invention or an (oxy)hydroxide of the present invention. The precursor of the present invention is in the form of a particulate (oxy)hydroxide of TM, wherein TM refers to a metal of which at least 97 mol % is a transition metal, TM includes manganese and nickel, and at least 50 mol % of TM is manganese; 0≦x<1, 1 <y≦2、0≦t≦0.1、 wherein the particulate transition metal (oxy)hydroxide has an average secondary particle size D50 in the range of 2 to 15 μm, preferably 3 to 8 μm; Such secondary particles are essentially agglomerates of radially oriented primary particles.

[0053] "Essentially radially oriented" does not require perfect radial orientation, but includes a maximum deviation of 5 degrees from perfect radial orientation upon SEM analysis.

[0054] Furthermore, at least 60% of the volume of the secondary particles is filled with radially oriented primary particles, and preferably only a small inner portion of the volume of the particles, e.g., at most 40%, preferably at most 20%, is filled with, e.g., randomly oriented, radially oriented primary particles.

[0055] Preferably, the precursor of the present invention exhibits reflections at 8.6-9.0 (a), 16.00-18.00 (b), and 21.40-22.00° 2θ (c) in an X-ray diffraction analysis recorded with Cu-Kα radiation.

[0056] Particulate metal (oxy)hydroxides according to general formula (II) are preferred. TMO x (OH) y (CO3) t (II) Preferably, TM corresponds to formula (I) Ni a M 1 b Mn c (I) (In the formula, M1 is at least one metal selected from Co, Ti, Zr, Nb, Ta, W, Sb, Sr, Al and Mg, a is a number in the range of 0.20 to 0.50, preferably 0.30 to 0.40, b is a number ranging from 0 to 0.05, preferably 0 or 0.02 to 0.04, c is a value in the range of 0.50 to 0.80, preferably 0.60 to 0.70, a+b+c=1.0).

[0057] In one embodiment of the present invention, the TM contains only Mn and Ni.

[0058] In one embodiment of the present invention, the (oxy)hydroxide of the present invention is 2 to 50 m 2 / g, which is determined, for example, by nitrogen adsorption according to DIN-ISO 9277:2003-05 after outgassing at 120° C. for 1 hour.

[0059] In one embodiment of the present invention, the particle size distribution ([(D90)-(D10)] divided by (D50)) of the (oxy)hydroxide of the present invention is in the range of 0.3 to 2, preferably 0.5 to 1.0.

[0060] In one embodiment of the present invention, the average shape factor of the secondary particles of the (oxy)hydroxide of the present invention, as determined by scanning electron microscopy ("SEM") imaging at 1000x magnification, is greater than 0.80, preferably at least 0.85. The upper limit is 1.0, or at least a maximum of 0.98. The imaging involves analyzing a representative sample of 100 particles. The shape factor of each particle was calculated from the perimeter and area determined from the top-view SEM image.

[0061] Shape factor = (4π - area) / (perimeter) 2

[0062] A perfect sphere has a shape factor of 1.0, but anything that deviates from a perfect sphere has a shape factor less than 1.0.

[0063] Therefore, the average shape factor is determined by averaging at least 30 particles, for example 30 to 40 particles.

[0064] A further aspect of the present invention relates to a method of using the precursor of the present invention for the manufacture of a cathode active material for a lithium ion battery. A further aspect of the present invention relates to a method of manufacturing a cathode active material for a lithium ion battery, said method comprising the steps of: (1) mixing at least one precursor of the present invention with at least one compound of lithium selected from lithium hydroxide, lithium carbonate and lithium peroxide, and optionally with at least one oxide or (oxy)hydroxide or sulfate of Mg, Al, Ti, Zr, Nb, Ta, W or Mo; (2) A step of heating the mixture obtained from step (1) to 800 to 1000°C, preferably 850 to 970°C. Includes.

[0065] Examples of suitable oxides or (oxy)hydroxides or sulfates of Mg, Al, Ti, Zr, Nb, Ta, W or Mo include MgO, Mg(OH)2, MgSO4, AlOOH, Al(OH)3, Al2O3, Al2(SO4)3, TiO(OH)2, TiO2, TiOSO4, Ti(OH)4, TiO2·aq, Zr(OH)4, ZrO(OH)2, ZrO2, ZrOSO4, ZrO2·aq, Nb2O5, niobic acid, Ta2O5, WO3, MoO3, and combinations of at least two of the foregoing.

[0066] The stoichiometric ratio of lithium to TM is preferably in excess of metal from TM.

[0067] The heating in step (2) can be carried out in a kiln, such as a rotary kiln, a roller hearth kiln, or a pusher kiln. The duration of step (2) is in the range of 3 to 24 hours, preferably 4 to 12 hours.

[0068] In one embodiment of the present invention, the temperature is increased before reaching a desired temperature of 800° C. to 1000° C., preferably 850° C. to 970° C. For example, the mixture of step (1) is first heated to 250 to 350° C., then kept constant for 10 minutes to 4 hours, then increased to 400 to 550° C., kept constant for 10 minutes to 4 hours, and then increased to 800 to 1000° C., preferably 850 to 970° C.

[0069] In one embodiment of the present invention, the heating rate in step (2) is in the range of 0.1 to 10° C. / min.

[0070] In one embodiment of the present invention, step (2) is followed by a post-treatment, hereinafter referred to as step (3), using, for example, water, an aqueous solution of aluminum sulfate, magnesium sulfate, titanium sulfate, or zirconium sulfate, or sulfuric acid, or a combination of sulfuric acid and aluminum sulfate, titanium sulfate, or magnesium sulfate. Such a treatment is preferably followed by another heat treatment at, for example, 300 to 600°C.

[0071] In one embodiment of the invention, the treatment is carried out with a solution of a compound of Mg, Al, Ti or Zr in a mineral acid, for example a solution of Al2(SO4)3 in aqueous H2SO4.

[0072] The treatment in step (3) can be carried out by adding a solution of a mineral acid or a compound of Mg, Al, Ti, or Zr to the cathode active material of step (2) and then allowing the resulting mixture to interact, which can be enhanced by stirring.

[0073] In one embodiment of the present invention, step (3) is carried out at a temperature in the range of 5 to 85° C., preferably 10 to 60° C. Ambient temperature is particularly preferred.

[0074] In one embodiment of the present invention, step (3) is carried out at atmospheric pressure. However, it is preferred to carry out step (3) at 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.

[0075] In one embodiment of the present invention, step (3) is carried out in an agitated filter apparatus, such as an agitated pressure filter or an agitated suction filter. The duration of treatment of the material obtained from step (2) with a compound of Mg, Nb, W, Al, Ti or Zr may range from 2 to 60 minutes, preferably from 10 to 45 minutes.

[0076] In one embodiment of the present invention, the volume ratio of the material obtained from step (2) to the solution of a mineral acid or a compound of Mg, Nb, W, Al, Ti or Zr is in the range of 1:1 to 1:10, preferably 1:1 to 1:5, respectively.

[0077] In one embodiment of the present invention, step (3) is repeated, for example, 1 to 10 times. In a preferred embodiment, step (3) is performed only once.

[0078] A further aspect of the present invention relates to a cathode active material, hereinafter also referred to as the cathode active material of the present invention. The cathode active material of the present invention has the general formula Li 1+k TM 1-k O2, wherein k is in the range of 0.1 to 0.3, and TM refers to a combination of metals of which at least 97 mol % is a transition metal, wherein TM includes manganese and nickel, and at least 50 mol % of TM is manganese; wherein the particulate cathode active material has an average secondary particle size D50 in the range of 2 to 15 μm, preferably 3 to 8 μm; Such secondary particles are aggregated from essentially radially oriented primary particles, and the secondary particles have an average shape factor of greater than 0.80, preferably at least 0.85, as determined by SEM imaging at 1000x magnification.

[0079] "Essentially radially oriented" does not require perfect radial orientation, but includes a maximum deviation of 5 degrees from perfect radial orientation upon SEM analysis.

[0080] Furthermore, at least 60% of the volume of the secondary particles is filled with radially oriented primary particles, and preferably only a small inner portion of the volume of the particles, e.g., at most 40%, preferably at most 20%, is filled with, e.g., randomly oriented, radially oriented primary particles.

[0081] In one embodiment of the present invention, TM corresponds to general formula (I) Ni a M 1 b Mn c (I) (In the formula, M 1 is at least one metal selected from Co, Ti, Zr, Nb, Ta, W, Sb, Sr, Al and Mg, a is a number in the range of 0.20 to 0.50, preferably 0.30 to 0.40, b is a number ranging from 0 to 0.05, preferably 0 or 0.02 to 0.04, c is a value in the range of 0.50 to 0.80, preferably 0.60 to 0.70, a+b+c=1.0).

[0082] In one embodiment of the present invention, the TM contains only Mn and Ni.

[0083] In one embodiment of the present invention, the cathode active material of the present invention is a tantalum oxide of the general formula Li coated with at least one oxide compound of Nb, W, Ti or Zr, preferably Nb, Ti or Zr. 1+k TM 1-k It contains secondary particles including primary particles of O2.

[0084] A further aspect of the present invention relates to electrodes comprising at least one electrode active material according to the present invention. These are particularly useful for lithium-ion batteries. Lithium-ion batteries comprising at least one electrode according to the present invention exhibit good discharge behavior. An electrode comprising at least one electrode active material according to the present invention is also referred to below as a cathode according to the present invention or a cathode according to the present invention.

[0085] In particular, the cathode of the present invention comprises: (A) at least one cathode active material of the present invention; (B) Carbon in a conductive state, (C) a binder polymer, also called binder or binder (C), and preferably (D) Current collector Contains:

[0086] In a preferred embodiment, the cathode of the present invention comprises, based on the sum of (A), (B), and (C): (A) 80 to 98% by weight of the cathode active material of the present invention; (B) 1 to 17 mass% carbon; (C) 1 to 15 mass % of a binder polymer Contains:

[0087] The cathode according to the present invention may contain additional components, such as, but not limited to, a current collector, such as aluminum foil, and may further contain conductive carbon and a binder.

[0088] The cathode according to the present invention contains a conductively modified carbon, also referred to simply as carbon (B), which can be selected from soot, activated carbon, carbon nanotubes, graphene, graphite, and a combination of at least two of the foregoing.

[0089] 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.

[0090] 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.

[0091] 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 may be HDPE or LDPE.

[0092] 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.

[0093] 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, 1,2-diphenylethylene and copolymers with α-methylstyrene are also understood to mean.

[0094] Another preferred binder (C) is polybutadiene.

[0095] Other suitable binders (C) are selected from polyethylene oxide (PEO), cellulose, carboxymethyl cellulose, polyimides and polyvinyl alcohol.

[0096] 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:

[0097] The binder (C) may be a crosslinked or non-crosslinked (co)polymer.

[0098] 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.

[0099] 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.

[0100] The cathode of the present invention may contain 1 to 15% by weight of binder(s) relative to the electrode active material. In other embodiments, the cathode of the present invention may contain 0.1 to less than 1% by weight of binder(s).

[0101] A further aspect of the invention is a battery containing at least one cathode comprising the electrode active material of the invention, carbon and a binder, at least one anode, and at least one electrolyte.

[0102] The cathode embodiment of the present invention has already been described in detail above.

[0103] The anode may contain at least one anode active material such as carbon (graphite), TiO, lithium titanium oxide, silicon, or tin. The anode may further contain a current collector, for example, a metal foil such as copper foil.

[0104] The electrolyte may include at least one non-aqueous solvent, at least one electrolyte salt, and optionally, additives.

[0105] The non-aqueous solvent for the electrolyte 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.

[0106] 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.

[0107] The molecular weight M of suitable polyalkylene glycols, especially suitable polyethylene glycols, W may be at least 400 g / mol.

[0108] 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.

[0109] 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.

[0110] Examples of suitable cyclic ethers are tetrahydrofuran and 1,4-dioxane.

[0111] Examples of suitable acyclic acetals are, for example, dimethoxymethane, diethoxymethane, 1,1-dimethoxyethane and 1,1-diethoxyethane.

[0112] An example of a suitable cyclic acetal is 1,3-dioxane, and especially 1,3-dioxolane.

[0113] Examples of suitable acyclic organic carbonates are dimethyl carbonate, ethyl methyl carbonate and diethyl carbonate.

[0114] Examples of suitable cyclic organic carbonates are compounds according to general formulas (III) and (IV):

[0115] [ka]

[0116] (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).

[0117] 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 each hydrogen. In another embodiment, R 1 is fluorine and R 2 and R 3 are hydrogen atoms.

[0118] Another preferred cyclic organic carbonate is vinylene carbonate of formula (V):

[0119] [ka]

[0120] 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.

[0121] The electrolyte further comprises at least one electrolyte salt. Suitable electrolyte salts are, in particular, lithium salts. Examples of suitable lithium salts include 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).

[0122] Preferred electrolyte salts are selected from LiC(CF3SO2)3, LiN(CF3SO2)2, LiPF6, LiBF4, LiClO4, with LiPF6 and LiN(CF3SO2)2 being particularly preferred.

[0123] In one embodiment of the present invention, the battery according to the present invention includes one or more separators by which the electrodes are mechanically separated. Suitable separators are polymer films, particularly porous polymer films, that are unreactive with metallic lithium. Particularly suitable materials for the separator are polyolefins, particularly film-forming porous polyethylene and film-forming porous polypropylene.

[0124] A separator made of polyolefin, particularly polyethylene or polypropylene, can have a porosity in the range of 35 to 45%. Suitable pore sizes are, for example, in the range of 30 to 500 nm.

[0125] In another embodiment of the present invention, the separator can be selected from a PET nonwoven fabric filled with inorganic particles. Such a separator 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.

[0126] The battery according to the invention further comprises a housing which may have any shape, for example a cube, or the shape of a cylindrical disk or can. In one variant, a metal foil configured as a pouch is used as the housing.

[0127] The battery according to the present invention exhibits good discharge behavior, for example very good discharge and cycling behavior at low temperatures (below 0° C., for example −10° C. or less).

[0128] 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.

[0129] 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. [Example]

[0130] The present invention is further illustrated by examples.

[0131] Brief description of the diagram / drawing: Figure 1 shows top-view SEM images of the inventive precursors TM-OH.1 (a, b) and TM-OH.2 (c, d). Top-view SEM images of the comparative precursor C-TM-OH.3 are shown in panels (e) and (f).

[0132] Particle size measurements were performed using a Mastersizer 3000 from Malvern Panalytical GmbH. Samples were filled into the instrument until a light blocking ratio between 4.0 and 14.0% was achieved. The volume-based particle size distribution (PSD) of each was determined by laser diffraction based on Mie scattering theory. H2O, with a refractive index of 1.33, was selected as the dispersant, and a solid phase with a refractive index of 2.19 was selected.

[0133] I. Preparation of precursor TM-OH Manufacturing example, general description: During all precipitation experiments, the stirred vessel had a constant nitrogen overflow. pH values ​​were measured at 23°C.

[0134] Aqueous solution (α.1): NiSO4 and MnSO4 (molar ratio 1:2), total TM concentration 1.65 mol / kg Aqueous solution (β.1): NaOH aqueous solution (25% by mass) I.1 Preparation of the precursor TM-OH.1 of the invention The inventive precursor TM-OH.1 was prepared in a 2.4 L stirred vessel equipped with a dosing unit containing a coaxial mixer. Additionally, the stirred vessel contained an overflow system and a clarifier. The agitator consisted of a stirring shaft equipped with two four-bladed pitch-blade turbines. The stirred vessel was filled with 2 L of deionized water and continuously stirred. The temperature was set at 55°C, and the energy absorption (ε 平均 ~6.3W / L).

[0135] Aqueous solutions (α.1) and (β.1) were introduced into a stirred vessel using a coaxial mixer. The formation of a slurry was observed. The total volumetric flow rate of solutions (α.1) and (β.1) was adjusted so that the average residence time was 5 hours. During the reaction, the pH was set to 10.0 and kept constant by adjusting the volumetric flow rate of solution (β.1). The precipitation reaction was carried out in continuous mode, with a mother liquor withdrawal rate of 35% (through the clarifier, relative to the total volumetric flow rate). The resulting slurry was recovered by overflow. The recovered slurry contained approximately 400 g / L of TM-OH.1. TM-OH.1 was recovered by filtration, washing with solution (β.1) (1 kg of solution (β.1) per 1 kg of solid TM-OH.1), and deionized water. TM-OH.1 was then dried at 120 °C for 14 hours.

[0136] I.2 Preparation of the precursor TM-OH.2 of the invention Example I.1 was repeated, except that the mother liquor was not removed through a clarifier and the agitation energy input was set at approximately 5.4 W / L. The slurry removed through the overflow system contained 120 g / L of solids. TM-OH.2 was obtained.

[0137] I.3 Preparation of comparative precursor C-TM-OH.3 The production of C-TM-OH.3 was carried out in a 30 L stirred vessel without a coaxial mixer. The agitator consisted of a stirring shaft equipped with two four-blade pitch-blade turbines. The aqueous solutions (α.1) and (β.1) were introduced into the stirred vessel through separate dosing pipes. The formation of a slurry was observed. The total volumetric flow of the aqueous solutions (α.1) and (β.1) was adjusted to give an average residence time of 12 hours. The pH value was set to 11.5 and kept constant by a pH control circuit that adjusted the volumetric flow of the aqueous solution (β.1).

[0138] The slurry removed by the overflow system contained 120 g / L of solids. C-TM-OH.3 was recovered by filtration, washing with solution (β.1) (1 kg of solution (β.1) per kg of solid C-TM-OH.3), and deionized water. C-TM-OH.3 was then dried at 120 °C for 14 hours.

[0139] SEM images of the resulting precursors TM-OH.1, TM-OH.2, and C-TM-OH.3 are shown in FIG. 1, and cross-sectional views are shown in FIG.

[0140] [Table 1]

[0141] II. Synthesis of Cathode Active Materials from Precursors of the Invention and Comparative Precursors II.1 Synthesis of cathode active materials CAM.1 and CAM.2 from TM-OH.1 and TM-OH.2 Each cathode active material was synthesized from the inventive precursor TM-OH.1 or TM-OH.2 by mixing the dried precursor with Li2CO3 and 0.1 mol% Zr(OH)4 and TiO2, each based on the total of Mn and Ni, in a molar ratio of 1.36:1 Li:(Ni + Mn + Ti + Zr). The resulting mixture was loaded into a crucible, heated to 950 °C at 1.5 °C / min, and held at this temperature for 5 hours. The resulting cathode active material was then cooled to room temperature and sieved through a 32 μm sieve before post-treatment. The calcined product was obtained.

[0142] For post-treatment purposes, each calcined material was treated with a mixture of aqueous H2SO4 and Al2(SO4)3. 100 g of water, 200 g of 0.4 M H2SO4, and 37 μmol of Al2(SO4)3 were added to 100 g of calcined material, respectively, and stirred for 30 minutes. After filtration, the CAM was washed with a washing medium (4:1 water:calcined material), filtered, and dried under vacuum. Finally, the thus-treated material was re-annealed at 400 °C for 5 hours at a heating rate of 3 °C / min, yielding CAM.1 or CAM.2, respectively. A cross-sectional SEM image of CAM.1 is shown in Figure 3.

[0143] II.2. Synthesis of Comparative Cathode Material from Comparative Precursor C-TM-OH.3 Comparative cathode active material C-CAM.3 was synthesized from the inventive precursor C-TM-OH.3 by mixing the dried precursor with Li2CO3, and 0.1 mol% Zr(OH)4 and TiO2, each based on the total of Mn and Ni, in a molar ratio of 1.36:1 Li:(Ni + Mn + Ti + Zr). The resulting mixture was charged into a crucible, heated at 1.5 °C / min to 950 °C, and held at this temperature for 6 hours. The resulting calcined material was then cooled to room temperature and sieved through a 32 μm sieve before further processing.

[0144] For post-treatment purposes, the calcined material was treated with a mixture of aqueous H2SO4 and Al2(SO4)3. 100 g of water, 200 g of 0.4 M H2SO4, and 37 μmol of Al2(SO4)3 were added to 100 g of the comparative calcined material and stirred for 30 minutes. After filtration, the CAM was washed with a washing medium (4:1 water:calcined material), filtered, and dried under vacuum. Finally, the thus-treated material was re-annealed at 400 °C for 5 hours at a heating rate of 3 °C / min to obtain the comparative cathode active material C-CAM.3.

[0145] [Table 2]

[0146] The compacted density was determined at a pressure of 250 MPa.

[0147] III. Electrode, Electrolyte Preparation, and Electrochemical Evaluation of the Cathode Active Materials of the Invention and Comparative Cathode Active Materials III.1 Electrode preparation Electrodes with a composition of 94% cathode active material (CAM), 3% conductive agent (Super C65), and 3% polymer binder (polyvinylidene fluoride (PVDF), Solef 5130) were prepared by dissolving the binder in N-methyl-2-pyrrolidone and adding the conductive agent. The resulting slurry was dispersed using a planetary centrifugal mixer (ARE-250, Thinky Corp.; Japan), after which each CAM was added. The resulting mixture was dispersed again using the same equipment as above to obtain a homogeneous slurry. The slurry was then cast onto aluminum foil using a doctor blade method. After drying, circular electrodes with a diameter of 1.4 cm were punched out and 10 -3 It was dried at 120°C under reduced pressure at mbar for 12 hours. The mass gain was 15 mg / cm 2 It was adjusted to be.

[0148] III.2 Preparation of electrolyte A base electrolyte composition (EL Base 1) containing 12.7 wt. % LiPF, 26.2 wt. % ethylene carbonate (EC), and 61.1 wt. % ethyl methyl carbonate (EMC) was prepared (based on the total weight of EL Base 1), and 2 wt. % vinylene carbonate (VC) was added to this base electrolyte composition to obtain the final composition, EL Base 2, which was used in the electrochemical evaluation of electrodes based on the inventive and comparative CAMs.

[0149] III.3 Cell preparation and electrochemical evaluation A coin-shaped half-cell (20 mm diameter, 3.2 mm thick) containing the cathode prepared in Section III.1 as the working electrode and a lithium metal counter electrode was assembled and sealed in an Ar-filled glove box. The cathode, anode, and separator were stacked in the order cathode / / separator / / Li foil to form a half-coin cell. Then, 0.15 ml of the EL base 2 described above (Section III.2) was introduced into the coin cell.

[0150] Electrochemical testing of the aforementioned coin cells was performed using a Maccor 4000 battery cycler with lower and upper cutoff voltages of 3.0 V and 4.7 V (4.8 V for the activation cycle (first cycle)), respectively. After activation in the first cycle, a C-rate test was performed to reveal the rate capability of the CAM in the range of 0.2–3 C. After the C-rate test, the electrodes were cycled at 0.5 C in constant current–constant voltage (CCCV) mode. Table 3 provides a detailed overview of the different C-rates in the test protocol.

[0151] [Table 3]

[0152] The termination criteria for the constant voltage step in CCXCV mode was a CV step of 1 hour or a total current of 0.02C.

[0153] [Table 4]

Claims

1. A method for producing an (oxy)hydroxide of TM, wherein TM refers to a metal that is at least 97 mol % a transition metal, TM comprises manganese and nickel, and at least 50 mol % of TM is manganese, said method comprising the steps of: (a) providing an aqueous solution (α) of at least one water-soluble salt of said metal, and an aqueous solution (β) comprising an alkali metal hydroxide selected from NaOH and KOH; (b) combining solutions (α) and (β) at a pH value ranging from 9.5 to 10.3 to precipitate TM (oxy)hydroxides, wherein step (b) is carried out using at least one coaxial mixer comprising two coaxially oriented pipes, by means of which the aqueous solutions (β) and (α) are introduced into a stirred vessel; (c) recovering and drying the TM (oxy)hydroxide; A method comprising:

2. 10. The method of claim 1, wherein the outlet of the pipe of the coaxial mixer is below the level of the liquid.

3. 3. The method according to claim 1 or 2, wherein the aqueous solution (α) is introduced through an inner pipe of the mixer and the aqueous solution (β) is introduced through an outer pipe.

4. 4. The method according to any one of claims 1 to 3, wherein between steps (b) and (c), a sub-step (b+) is carried out, which comprises transferring the slurry from step (b) to a second stirred vessel and combining it therein with solutions (α) and (β) at a pH value ranging from 9.5 to 11.0 measured at 23°C, and step (c) is carried out in a continuous or semi-continuous mode, thereby further growing the (oxy)hydroxide of TM.

5. 5. The method according to any one of claims 1 to 4, wherein the drying in step (c) is carried out at a temperature in the range of 80 to 120°C.

6. 6. The method of claim 1, wherein the water-soluble salts of manganese and nickel in step (a) are sulfates.

7. 7. The method of any one of claims 1 to 6, wherein at regular intervals the nozzle is flushed with water to physically remove deposits of transition metal (oxy)hydroxides.

8. TM contains a metal according to formula (I), Ni a M 1 b Mn c (AND) (In the formula, M １ is at least one metal selected from Co, Ti, Zr, Nb, Ta, W, Sb, Sr, Al, and Mg; a is a number ranging from 0.20 to 0.50; b is a number ranging from 0 to 0.05; c is a number ranging from 0.50 to 0.80; 8. The method of claim 1, wherein a+b+c=1.

0.

9. Particulate metal (oxy)hydroxides according to general formula (II), TMO ｘ (OH) ｙ (CO ３ ) ｔ (II) wherein T M refers to a combination of metals at least 97 mol % of which are transition metals, T M comprises manganese and nickel, and at least 50 mol % of T M is manganese; 0≦x<1, 1<y≦2, and 0≦t≦0.1) the particulate transition metal (oxy)hydroxide has an average secondary particle size D50 in the range of 2 to 15 μm; A particulate metal (oxy)hydroxide in which such secondary particles are agglomerates from essentially radially oriented primary particles.

10. TM is Ni a M 1 b Mn c Corresponding to metals by (In the formula, M １ is at least one metal selected from Co, Ti, Zr, Nb, Ta, W, Sb, Sr, Al, and Mg; a is a number ranging from 0.20 to 0.50; b is a number ranging from 0 to 0.05; c is a number ranging from 0.50 to 0.80; The particulate metal (oxy)hydroxide according to claim 9, wherein a+b+c=1.

0.

11. 11. The particulate metal (oxy)hydroxide according to claim 9 or 10, which exhibits reflections at 8.6 to 9.0 (a), 16.00 to 18.00 (b), and 21.40 to 22.00 ° 2θ (c) in an X-ray diffraction analysis recorded with Cu-Kα radiation.

12. 2 to 50 m ２ 12. The particulate metal (oxy)hydroxide according to claim 9, having a BET specific surface area in the range of 1 / g.

13. The particulate metal (oxy)hydroxide according to any one of claims 9 to 12, wherein the particle size distribution calculated by dividing [(D90) - (D10)] by (D50) is in the range of 0.5 to 2.

14. 14. A particulate metal (oxy)hydroxide according to any one of claims 9 to 13, wherein the average shape factor of the secondary particles, as determined by SEM imaging at 1000x magnification, is greater than 0.

80.

15. 15. Use of the particulate metal (oxy)hydroxide according to any one of claims 9 to 14 for the manufacture of a cathode active material for a lithium ion battery.

16. The following process: (1) mixing at least one metal (oxy)hydroxide according to any one of claims 9 to 14 with at least one compound of lithium selected from lithium hydroxide, lithium carbonate and lithium peroxide, and optionally with at least one oxide or (oxy)hydroxide or sulfate of Mg, Al, Ti, Zr, Nb, Ta, W or Mo; and (2) Heating the mixture obtained from step (1) to 800-1000°C 1. A method for making a cathode active material for a lithium ion battery, comprising:

17. General formula Li １＋ｋ TM １－ｋ O ２ wherein k is in the range of 0.1 to 0.3, and T M refers to a combination of metals at least 97 mol % of which are transition metals, T M comprising manganese and nickel, and at least 50 mol % of T M is manganese; the particulate cathode active material has an average secondary particle size D50 in the range of 2 to 15 μm; A particulate cathode active material, wherein such secondary particles are aggregates of essentially radially oriented primary particles, and wherein the secondary particles have an average shape factor, as determined by SEM imaging at 1000x magnification, of greater than 0.80.

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