Process for making a particulate (OXY)hydroxide or oxide, particulate (OXY)hydroxide or oxide and use

Abstract

Process for making a particulate (oxy)hydroxide or oxide of TM wherein TM represents metals, wherein said process is performed in a cascade of at least two stirred tank reactors.

Description

[0001] Process for making a particulate (oxy) hydroxi de or oxide, particulate (oxy) hydroxi de or oxide and use

[0002] The present invention is directed towards a process for making a particulate (oxy)hydroxide or oxide of TM wherein TM represents metals, wherein TM comprises nickel and at least one metal selected from cobalt and manganese and wherein the nickel content of TM corresponds to formula (I), wherein said process is performed in a cascade of at least two stirred tank reactors and comprises the steps of:

[0003] (a) providing an aqueous solution (a1) containing a water-soluble salt of Ni and of at least one metal selected from Co and Mn, and an aqueous solution (pi) containing an alkali metal hydroxide and, optionally, an aqueous solution (y1) containing a complexing agent selected from ammonia, glycine, tartrate, citrate, and oxalate,

[0004] (b) combining, in a continuous stirred tank reactor, solution (cd) and solution (pi) and, if applicable, solution (y1), at a pH value in the range of from 11.0 to 13.5, thereby creating slurried solid particles of a hydroxide of TM with an average diameter (D50) in the range of from 1 to 2 pm,

[0005] (c) transferring particles from step (b) as a slurry into a second stirred tank reactor that is operated in the batch mode,

[0006] (d) providing an aqueous solution (a2) containing a water-soluble salt of Ni and of at least one metal selected from Co and Mn and, optionally, at least one transition metal other than nickel, and an aqueous solution (P2) containing an alkali metal hydroxide and, optionally, an aqueous solution (y2) containing a complexing agent selected from ammonia, glycine, tartrate, citrate, and oxalate,

[0007] (e) combining solution (a2) and solution (P2) and, if applicable, solution (y2), in said second stirred tank reactor at a pH value in the range of from 10.5 to 12.0 and with an average specific energy input in the range of from 140 to 600 W / kg, thereby growing the solid particles of a hydroxide of TM.

[0008] Lithiated transition metal oxides are currently being used as electrode active materials for lithium-ion batteries. Extensive research and developmental work have been performed in the past years to improve properties like charge density, specific energy, but also other properties like the reduced cycle life and capacity loss that may adversely affect the lifetime or applicability of a lithium-ion battery. Additional effort has been made to improve manufacturing methods. In a typical process for making cathode materials for lithium-ion batteries, first a so-called precursor is being formed by co-precipitating the transition metals preferably as hydroxides that may or may not be basic, for example oxyhydroxides. Hydroxides may be pre-calcined and turned into oxides or oxyhydroxides, or they are directly mixed with a source of lithium such as, but not limited to LiOH, U2O, U2O2 or U2CO3 and calcined (fired) at high temperatures. The source of lithium can be employed as hydrate(s) or in dehydrated form. The calcination - or firing - often also referred to as thermal treatment or heat treatment of the precursor - is usually carried out at temperatures in the range of from 600 to 1 ,000 °C. During the thermal treatment a solid-state reaction takes place, and the electrode active material is formed. The thermal treatment is performed in the heating zone of an oven or kiln.

[0009] A typical class of cathode active materials delivering high energy density contains a high amount of Ni (Ni-rich), for example at least 80 mol-%, referring to the content of non-lithium metals. However, the energy density still needs improvement.

[0010] To a major extent, properties of the precursor translate into properties of the respective electrode active material, such as particle size distribution, content of the respective transition metals and more. It is therefore possible to influence the properties of electrode active materials by steering the properties of the precursor.

[0011] It has been found desirable to make precursors with a narrow particle size distribution, see, e.g., EP 2 720 305 A. It is furthermore desired to provide precursors of high sphericity. In addition, fines formation in cathode active materials is not desired. Among others, the handling of solids with a high share of fines is more difficult.

[0012] In CN 112591807 A, a multi-stage co-precipitation process is disclosed that yields high-density precursors. In WO 2023 / 135055 and EP 4 149 889 B1 , further methods to manufacture precursors are disclosed.

[0013] It was an objective of the present invention to provide a process by which precursors of cathode active materials with a high porosity, a narrow particle size distribution, a low tendency of agglomerate formation and a high reactor efficiency can be made. It was further an objective to provide a precursor for cathode active materials that has a low tendency of fines formation and a low tendency of agglomerate formation. For cathode active materials with a smaller particle size, a broad particle size distribution is acceptable. It has been found that precursors that serve as a starting material for cathode active materials with a high volumetric energy density can be obtained by avoiding particle agglomeration during the start-up of seeding batch growth stages. Without wishing to be bound by any theory, we assume that a high solids content helps to efficiently avoid unwanted agglomeration. A conventional two-stage process does not allow to start with sufficiently high solids contents because in this case the final batch solids content would be unfavorably high.

[0014] Accordingly, the process as set out at the outset was found, hereinafter also referred to as inventive process. The inventive process is a process for making a particulate oxyhydroxide or oxide of TM. Said particulate oxyhydroxide or oxide then serves as a precursor for electrode active materials, and it may therefore also be referred to as precursor. The inventive process comprises the following steps (a) and (b) and (c) and (d) and (e) and (f) and (g), hereinafter also referred to as step (a) and step (b) and step (c) and step (d) and step (e) and step (f) and step (g), or briefly as (a) or (b) or (c) or (d) or (e) or (f) or (g), respectively. The inventive process will be described in more detail below.

[0015] The resultant (oxy) hydroxi de or oxide of TM is in particulate form. The particles size distribution may be determined by light scattering or LASER diffraction or electroacoustic spectroscopy, LASER diffraction being preferred. The particle size distribution may be characterized by the scan, (D90 - D10) divided by D50, D50 being the median value. Preferably, the span of the resultant (oxy)hydroxide is below 0.95, more preferably from 0.50 to 0.80, even more preferably 0.55 to 0.80. D10 and D90 are the respective percentiles.

[0016] In one embodiment of the present invention, the particle shape of the secondary particles of the resultant precursors is spheroidal, that are particles that have a spherical shape. Spherical spheroidal shall include not just those which are exactly spherical but also those particles in which the maximum and minimum diameter of at least 90% (number average) of a representative sample differ by not more than 10%.

[0017] In one embodiment of the present invention, the resultant precursors are comprised of secondary particles that are agglomerates of primary particles.

[0018] In one embodiment of the present invention the specific surface (BET) of the resultant precursors is in the range of from 2 to 120 m2 / g, determined by nitrogen adsorption, for example in accordance with to DIN-ISO 9277:2003-05. The precursor is an (oxy) hydroxi de of TM wherein TM is a combination of metals according to general formula (I), see below. Preferably, the precursor comprises nickel and cobalt and manganese.

[0019] Oxides of TM may contain residual hydroxyl groups or carbonate groups, for example in the range of from 100 to 1,000 ppm (by mass), determined by differential thermogravimetric methods (“DSC”) as weight loss at a temperature in the range of from 180 to 450°C.

[0020] In one embodiment of the present invention, TM is a combination of metals according to general formula (I)

[0021] (NiaCobMnc)i-dMd(I) with a being in the range of from 0.80 to 0.97, preferably from 0.83 to 0.95, b being zero or in the range of from 0.025 to 0.2, preferably from 0.025 to 0.15, c being in the range of from zero to 0.2, preferably from zero to 0.15, or from 0.01 to 0.15, and d being in the range of from zero to 0.1, preferably from zero to 0.05,

[0022] M is selected from Ti, Zr, Mo, W, Al, Mg, Nb, Sb, and Ta, a + b + c = 1 , and b + c > zero.

[0023] Preferably, d = zero.

[0024] TM may contain traces of further metal ions, for example traces of ubiquitous metals such as sodium, calcium or zinc, as impurities but such traces will not be taken into account in the description of the present invention. Traces in this context will mean amounts of 0.05 mol-% or less, referring to the total metal content of TM.

[0025] Step (a) includes providing an aqueous solution (a1) containing water-soluble salts of Ni and of at least one metal selected from Co and Mn, and, optionally, at least one further metal selected from Ti, Zr, Mo, W, Al, Mg, Nb, Sb, and Ta, and an aqueous solution (pi) containing an alkali metal hydroxide and, optionally, an aqueous solution (y1) containing a complexing agent selected from ammonia, glycine, tartrate, citrate, and oxalate.

[0026] The term “water-soluble salts” refers to salts that exhibit a solubility in distilled water at 25°C of 25 g / l or more, the amount of salt being determined under omission of crystal water and of water stemming from aquo complexes. Water-soluble salts of nickel and cobalt and manganese may preferably be the respective water-soluble salts of Ni2+and Co2+and Mn2+. Examples of water-soluble salts of nickel and cobalt and manganese are the sulfates, the nitrates, the acetates and the halides, especially the chlorides. Preferred are nitrates and sulfates, of which the sulfates are more preferred.

[0027] Said aqueous solution (a1) preferably contains Ni and further metal(s) in the relative concentration that is intended as TM of the precursor, or in one of the fractions of the precursor. Preferably, solution (cd) contains salts of nickel and cobalt and manganese.

[0028] Said aqueous solution (cd) preferably contains Ni and, optionally, further metal(s) in a total concentration of from 0.5 to 2.2 mol / l.

[0029] Solution (cd) may have a pH value in the range of from 2 to 5. In embodiments wherein higher pH values are desired, ammonia may be added to solution (cd). In other embodiments, no ammonia is added to solution (cd).

[0030] The inventive process is carried out in a cascade of at least two stirred tank reactors, for example 2 or 3 stirred tank reactors.

[0031] In step (a), in addition an aqueous solution of alkali metal hydroxide is provided, hereinafter also referred to as solution (pi). An example of an alkali metal hydroxides is caesium hydroxide, preferred is potassium hydroxide and a combination of sodium and potassium hydroxide, and even more preferred is sodium hydroxide.

[0032] In embodiments wherein solution (pi) contains alkali metal hydroxide, said solution (pi) may additionally contain some amount of carbonate, e.g., 0.1 to 2 % by weight, referring to the respective amount of alkali metal hydroxide, added deliberately or by aging of the solution or the respective alkali metal hydroxide.

[0033] Solution (pi) may have a concentration of alkali metal hydroxide in the range from 0.1 to 12 mol / l, preferably 6 to 10 mol / l.

[0034] The pH value of solution (P1) is preferably 13 or higher, for example 14.5. In the context of the present invention, pH values are determined at 23°C unless specifically noted otherwise.

[0035] In the inventive process, it is preferred to use ammonia. Solution (y1) - if applicable - contains a complexing agent selected from ammonia, glycine, tartrate, citrate, and oxalate. In the context of the present invention, the term glycine includes the compound glycine and its alkali metal salts, for example the potassium or preferably the sodium salt. The terms tartrate and oxalate include the respective free acids and the mono- and dialkali metal salts, for example the mono- or di-potassium salts or the mono- or disodium salts or mixed sodium and potassium salts. The term “citrate” includes citric acid and its alkali metal salts, for example the mono- or di- or trisodium salts and the mono-, di- and tripotassium salts.

[0036] In one embodiment of the present invention, solution (y1) has an ammonia concentration in the range of from 1 to 30% by weight.

[0037] In one embodiment of the present invention, solution (y1) contains in the range of from 0.05 to 1.0 mol-%, referring to TM, of a complexing agent selected from glycine, tartrate, citrate, and oxalate, or their respective alkali metal salts.

[0038] Step (b) includes combining solution (a1) and solution (pi) and, if applicable, solution (y1), at a pH value in the range of from 11.0 to 13.5, preferably 11.2 to 12.5, thereby creating particles of a hydroxide of TM with an average diameter (D50) in the range of from 1 to 2 pm, determined by light scattering. Said particles are slurried in an aqueous medium. Again, pH values are determined at 23°C unless specifically noted otherwise.

[0039] In one embodiment of the present invention, step (b) is performed at a temperature in the range from 10 to 85°C, preferably at temperatures in the range from 40 to 65°C.

[0040] In one embodiment of the present invention, step (b) is performed at a pressure in the range of from 500 mbar to 10 bar, preferably at ambient pressure.

[0041] In one embodiment of the present invention, an average specific energy of from 500 to 600 W / kg, preferably from 530 to 560 W / kg is introduced into the slurry in step (b), for example with a pitch-blade turbine, preferably with a Rushton turbine or with a combination of a pitch-blade turbine and a Rushton turbine. Stirrers may be one-stage or two-stage or multiple stage, for example three-stage or four-stage, two-stage and three-stage being preferred.

[0042] The energy introduction may be held constant during step (b) or be varied.

[0043] Step (b) is performed in a continuous stirred tank reactor (“CSTR”). A CSTR is usually equipped with an overflow. After step (b), preferably a slurry with particles with an average diameter (D50) in the range of from 1 to 2 pm is removed and fed to a second stirred tank reactor. Performing step (b) in a batch reactor is preferred. In one embodiment of the present invention, the stirred tank reactor in which step (b) is performed is equipped with a means of removing liquid phase, so-called mother liquor but leaving the solids in the stirred tank reactor. Examples are candle filters and clarifiers, for example lamella clarifiers.

[0044] In on embodiment of the present invention, the solids content of slurry removed from step (b) is in the range of from 100 to 200 g / l. The solids content is determined by dissolving the precipitate in sulfuric acid and determining the metal content by IC (Inductively Coupled Plasma).

[0045] In one embodiment of the present invention, step (b) is performed in a continuous stirred tank reactor operated with an average residence time in the range of from 5 to 15 hours, preferably from 7 hours to 12 hours. In embodiments wherein step (b) is performed in a batch reactor, a average residence time of 15 to 60 hours is preferred. In embodiments of step (b) with varying flow rates due to, e.g., varying feed rates of solution(s) (a2) and solution (P2) and, if applicable, solution (y2), a temporary residence time may be calculated. Usually, in embodiments with strongly varying flow rates of at least one of solution(s) (a2) and solution (P2) and, if applicable, solution (y2), the average residence time corresponds neither to the maximum nor the minimum residence time.

[0046] In step (c), the particles from step (b) are transferred as a slurry into a second stirred tank reactor. The second stirred tank reactor is operated as a batch reactor. In order to deal with a continuous supply of slurry from step (b) it is preferred to have to or more tank reactors for step (e) that may be operated in parallel.

[0047] Said transfer may be performed intermittently or continuously.

[0048] In the context of step (c), “the particles from step (b)” means that essentially all particles generated in step (b) are transferred. The losses are preferably less than 5% by weight.

[0049] Step (d) includes providing aqueous solution (a2) containing water-soluble salts of Ni and of at least one transition metal selected from Co and Mn, and, optionally, at least one further metal selected from Ti, Zr, Mo, W, Al, Mg, Nb, Sb, and Ta, and an aqueous solution (P2) containing an alkali metal hydroxide and, optionally, an aqueous solution (y2) containing ammonia.

[0050] In the context of the present invention, the term “a solution contains a metal” shall mean that such solution contains a salt of said metal. Said aqueous solution (a2) preferably contains Ni and further metal(s) in the relative concentration that is intended as TM of the precursor, or in one of the fractions of the precursor.

[0051] Solution (a2) may have the same composition as solution (a1) or a different one.

[0052] Said aqueous solution (a2) preferably contains Ni and, optionally, further metal(s) in a total concentration of from 0.1 to 12 mol / l, preferably 6 to 10 mol / l.

[0053] Solution (a2) may have a pH value in the range of from 2 to 5. In embodiments wherein higher pH values are desired, ammonia may be added to solution (a2).

[0054] Said aqueous solution (a2) preferably contains Ni and, optionally, further metal(s) in a total concentration of from 0.5 to 2.2 mol / l.

[0055] In step (a), in addition an aqueous solution of alkali metal hydroxide is provided, hereinafter also referred to as solution (P2). Solution (P2) may have a concentration of alkali metal hydroxide in the range from 0.1 to 12 mol / l, preferably 6 to 10 mol / l.

[0056] The pH value of solution (P2) is preferably 13 or higher, for example 14.5.

[0057] In the inventive process, it is possible to use ammonia but to feed it separately as solution (y2) or in solution (P2) or in solution (a2).

[0058] Solution (P2) may have the same composition as solution (pi) or a different one, preferably the same.

[0059] Solution (y2) may have the same composition as solution (y1) or a different one, preferably the same.

[0060] In one embodiment of the present invention, solution (y2) has an ammonia concentration in the range of from 1 to 30% by weight.

[0061] In one embodiment of the present invention, solution (y2) contains in the range of from 0.05 to 1.0 mol-%, referring to TM, of a complexing agent selected from glycine, tartrate, citrate, and oxalate, or their respective alkali metal salts. Step (e) includes combining solution (a2) and solution (P2) and, if applicable, solution (y2), at a pH value in the range of from 10.5 to 13.0, preferably at a pH value lower than in step (b), for example by at least 0.5 units, preferably 11 to 12.5, thereby growing particles of a hydroxide of TM. Said particles are slurried in aqueous medium.

[0062] In one embodiment of the present invention, step (e) is performed at a temperature in the range from 10 to 85°C, preferably from 40 to 65°C. Steps (b) and (e) may be performed at different temperatures or preferably at the same.

[0063] In one embodiment of the present invention, step (e) is performed at a pressure in the range of from 500 mbar to 10 bar, preferably at ambient pressure.

[0064] In step (e), an average specific energy input of from 140 to 600 W / kg, preferably from 165 to 600 and more preferably from 165 to 560 W / kg is introduced into the slurry in step (e), for example with a stirrer as used in step (b). The average specific energy input may be constant over the time of step (e) or variable. In case the average specific energy input is not constant, the above value refers to the average value.

[0065] In one embodiment of the present invention, the average particle diameter (d50) of (oxy)hydroxide made in step (e) is in the range of from 3.5 to 6.0 pm but in any case bigger than at the end of step (b) and in step (c). The average diameter is volume based and preferably determined by dynamic light scattering.

[0066] In one embodiment of the present invention, the solids content at the end of step (e) is in the range of from 200 to 800 g / l.

[0067] In one embodiment of the present invention, step (e) has a duration in the range of from 7 to 45, preferably 15 to 40 hours.

[0068] One or more feed rates of solutions (a2), (P2), and (y2) in step (e) may be constant or vary, they may, for example, increase or decrease or oscillate. In case the feed rates are constant, the average residence time is identical to the residence time.

[0069] In embodiments of step (e) with varying flow rates due to, e.g., varying feed rates of solution(s) (a2) and solution (P2) and, if applicable, solution (y2), a temporary residence time may be calculated. Usually, in embodiments with strongly varying flow rates of at least one of solution(s) (a2) and solution (P2) and, if applicable, solution (y2), the average residence time corresponds neither to the maximum nor the minimum residence time. In one embodiment of the present invention, step (g) is performed at a temperature in the range from 10 to 85°C, preferably from 40 to 65°C. Steps (g) and (e) may be performed at different temperatures or preferably at the same.

[0070] In one embodiment of the present invention, step (g) is performed at a pressure in the range of from 500 mbar to 10 bar, preferably at ambient pressure.

[0071] In one embodiment of the present invention, in steps (b) and (e), mother liquor is withdrawn from the reactors, for example by means of a clarifier, for example a lamellar clarifier, a candle filter or a thickener. Said mother liquor may contain solid particles of precursor, for example from 2 mg / l to 20 g / l, or may be free from solid particles for the naked eye.

[0072] In one embodiment of the present invention, slurry from steps (b) and (e) are transferred into a buffer vessel before subjecting them to the next co-precipitation steps.

[0073] In one embodiment of the present invention, the inventive process comprises the additional step (f) of separating particulate (oxy) hydroxi de by a solid-liquid separation method and subsequent drying.

[0074] By performing the inventive process, an aqueous slurry is formed. From said aqueous slurry, a particulate mixed hydroxide may be obtained by performing one or more solid-liquid separation steps, for example filtering or centrifuge. Additional work-up measures may be taken such as washing, e.g., with water or ammonia or NaOH solution, dehydration, drying under inert gas or air, or the like. If dried under air, a partial oxidation may take place, and a mixed oxyhydroxide of TM is obtained. Drying may be performed at a temperature in the range of from 100 to 150°C.

[0075] In one embodiment of the present invention, the inventive process comprises a heating step (g) at a temperature in the range of from 400 to 550°C in the absence of a lithium compound. By step (i), the precursor is converted into an oxide of TM. Step (g) may be performed in a rotary kiln, in a fluidized bed, or in a roller hearth kiln.

[0076] In one embodiment of the present invention, step (g) is performed under an atmosphere of air, of oxygen-enriched air, or of pure oxygen.

[0077] In one embodiment of the present invention, step (g) has a duration in the range of from 1 hour to 12 hours. Precursors obtained according to the inventive process are excellent starting materials for cathode active materials which are suitable for producing batteries with a high volumetric energy density. The volumetric density is dependent of the press density and the discharge capacity of a given cathode active material.

[0078] A further aspect of the present invention is related to precursors, hereinafter also referred to as inventive precursors. In one embodiment of the present invention, inventive precursors are particulate (oxy)hydroxides of TM with a span of the particle diameter distribution (D90- D10) / D50 below 0.95, preferably from 0.50 to 0.80, even more preferably 0.55 to 0.80, wherein TM comprises nickel and at least one metal selected from cobalt and manganese, and wherein the secondary particles of inventive precursors are composed of primary particles.

[0079] Another embodiment of inventive precursors are particulate oxides of TM with a span of the particle diameter distribution (D90-D10) / D50 below 0.95, preferably from 0.50 to 0.80, more preferably 0.55 to 0.80, wherein TM comprises nickel and at least one metal selected from cobalt and manganese, and wherein the particles are composed of primary particles.

[0080] The span in each case refers to the secondary particles. The secondary particles are agglomerated from primary particles that are essentially radially oriented.

[0081] The span of inventive precursors is below 0.95, for example in the range of from 0.50 to 0.80, more preferably 0.55 to 0.80. The percentiles of D10, D90 and the median value are preferably determined by light scattering or LASER diffraction or electroacoustic spectroscopy, LASER diffraction being preferred.

[0082] TM is defined as outlined above.

[0083] Inventive particulate (oxy)hydroxide of TM has a ratio of the FWHM values of the following reflections determined by XRD analysis, Mo Ka radiation: (001) / (101) is in the range from 0.75 to 0.90 A (Angstrom) and (001) / (100) is in the range from 1.95 to 2.25 A. Furthermore, inventive particulate particles have an absolute crystallite sizes according to the Debye Scherrer equation in the range of 90 to 105 A for the (001) reflection, 195 to 220 A for the (100) reflection and 70 to 85 A for the (101) reflection.

[0084] In one embodiment of the present invention, inventive particulate transition metal (oxy) hydroxi de has an average secondary particle diameter D50 in the range of from 3.0 to 5.0 pm, preferably 3.5 to 4.5 pm and more preferably 3.7 to 4.2 pm. In one embodiment of the present invention, TM is a combination of metals according to general formula (I)

[0085] (NiaCobMnc)i-dMd(I) with a being in the range of from 0.80 to 0.97, preferably from 0.83 to 0.95, b being zero or in the range of from 0.025 to 0.2, preferably from 0.025 to 0.15, c being in the range of from zero to 0.2, preferably from zero to 0.15, or from 0.01 to 0.15, and d being in the range of from zero to 0.1, preferably from zero to 0.05,

[0086] M is selected from Ti, Zr, Mo, W, Al, Mg, Nb, Sb, and Ta, a + b + c = 1.

[0087] TM may contain traces of further metal ions, for example traces of ubiquitous metals such as sodium, calcium or zinc, as impurities but such traces will not be taken into account in the description of the present invention. Traces in this context will mean amounts of 0.05 mol-% or less, referring to the total metal content of TM.

[0088] Inventive precursors may contain some carbonate. Carbonate may have been incorporated inadvertently, for example from carbonate of alkali metal hydroxide, or by absorption of CO2 when exposed to air. Inventive precursors may as well contain some counterion from a water- soluble salt that has served as source of, e.g., nickel during the precursor manufacture. Such counterion is preferably sulfate. The amounts of impurities such as carbonate and counterion from the source of nickel and further metal(s) preferably does not exceed 1 % by weight of the inventive precursors.

[0089] In one embodiment of the present invention, inventive precursors have a specific surface according to BET (hereinafter also “BET-Surface”) in the range of from 2 to 120 m2 / g, preferably from 4 to 50m2 / g. The BET surface may be determined by nitrogen adsorption after outgassing of the sample at 200°C for 30 minutes or more and beyond this accordance with DIN ISO 9277:2010.

[0090] As outlined before, the secondary particles are agglomerated from primary particles that are essentially radially oriented. Furthermore, at least 60% of the secondary particle volume is filled with radially oriented primary particles. Preferably, only a minor inner part, for example at most 40%, preferably at most 20%, of the volume of those particles is filled with non-radially oriented primary particles, for example, in random orientation.

[0091] Inventive oxide precursors have a total pore / intrusion volume in the range of from 0.1 to 0.5 ml / g, preferably 0.12 to 0.3 ml / cm3in the pore size range from 20 to 600 A, determined by N2 adsorption, determined in accordance with DIN 66134 (1998), when the sample preparation for the N2 adsorption measurement is done by degassing at 120°C for 60 minutes.

[0092] In a preferred embodiment, the average pore size of inventive oxide precursors is in the range of from 30 to 500 A, preferably 50 to 200 A, determined by N2 adsorption.

[0093] In one embodiment of the present invention, inventive oxide precursor has an average secondary particle diameter D50 in the range of from 3.0 to 5.0 pm, preferably 3.5 to 4.5 pm and more preferably 3.7 to 4.2 pm.

[0094] In one embodiment of the present invention, in inventive (oxy) hydroxi de of TM at least 60 vol.-% of the secondary particles consist of primary particles that are radially oriented or display a maximum deviation to a perfectly radial orientation of 11 degrees, and wherein said particulate precursor has a total pore / intrusion volume in the range of from 0.033 to 0.1 ml / g, determined by N2 adsorption.

[0095] In one embodiment of the present invention, in inventive oxide of TM, at least 60 vol.-% of the secondary particles consist of primary particles that are radially oriented or display a maximum deviation to a perfectly radial orientation of 11 degrees.

[0096] Inventive precursors have an excellent spherical shape. They are almost perfectly spherical, the average form factor being 0.90 or more. The (average) form factor is determined as follows:

[0097] The form factor of individual particles is calculated from the perimeter and area determined from top view SEM images:

[0098] Form factor = (4TT area) / (perimeter)2

[0099] While a perfect sphere would possess a form factor of 1.0, any deviation from perfect sphericity leads to form factors < 1.0. To determine the average form factor, the form factor is first determined for at least 50 individual particles of a representative sample and then averaged. This is why it may be referred to as average form factor as well.

[0100] In one embodiment of the present invention, inventive precursors have a specific surface according to BET in the range of from 2 to 120 m2 / g, determined in accordance with DIN after heating to 120°C.

[0101] Precursors obtained according to the inventive process are excellent starting materials for cathode active materials which are suitable for producing batteries with a high volumetric energy density and excellent cycling stability. Such cathode active materials are made by mixing with a source of lithium, e.g., U2O or LiOH or U2CO3, each water-free or as hydrates, and calcination, for example at a temperature in the range of from 600 to 1000°C. A further aspect of the present invention is thus the use of inventive precursors for the manufacture of cathode active materials for lithium-ion batteries, and another aspect of the present invention is a process for the manufacture of cathode active material for lithium-ion batteries - hereinafter also referred to as inventive calcination - wherein said process comprises the steps of mixing an inventive precursor with a source of lithium and thermally treating said mixture at a temperature in the range of from 600 to 1000°C. Preferably, the ratio of inventive precursor and source of lithium in such process is selected that the molar ratio of Li and TM is in the range of from 0.95:1 to 1.2:1.

[0102] Said precursors lead to cathode active materials with a very good volumetric energy density. Without wishing to be bound by any theory, it may be assumed that the orientation of the primary crystals and the high sphericity leads to such advantageous properties.

[0103] Examples of inventive calcinations include heat treatment according to a two-temperature profile. The first temperature is in the range from 350 to 550°C and the second in the range of from 750-900°C, preferably 780 to 850°C. The terms “treating thermally” and “heat treatment” are used interchangeably in the context of the present invention.

[0104] In one embodiment of the present invention, the mixture obtained for the inventive calcination is heated to a temperature up to 900 °C with a heating rate of 0.1 to 10 °C / min.

[0105] In one embodiment of the present invention, the duration of the calcination is in the range of from 9 to 20 hours. The duration refers to the duration at the maximum temperature. In one embodiment of the present invention, the temperature is ramped up before reaching the desired temperature of from 750 to 900°C, preferably 780 to 850°C. Such temperature refers to the maximum temperature. For example, first the mixture obtained from step (d) is heated to a temperature to 350 to 550°C and then held constant for a time of 10 min to 4 hours, and then it is raised to 750°C up to 900°C and then held at 750 to 900°C for 10 minutes to 14 hours.

[0106] In one embodiment of the present invention, the inventive calcination is performed in a roller hearth kiln, a pusher kiln or a rotary kiln or a combination of at least two of the foregoing. Rotary kilns have the advantage of a very good homogenization of the material made therein. In roller hearth kilns and in pusher kilns, different reaction conditions with respect to different steps may be set quite easily. In lab scale trials, box-type and tubular furnaces and split tube furnaces are feasible as well.

[0107] In one embodiment of the present invention, the inventive calcination is performed in an oxygen-containing atmosphere, for example in a nitrogen-air mixture, in a rare gas-oxygen mixture, in air, in oxygen or in oxygen-enriched air. In a preferred embodiment, the atmosphere in step (d) is selected from air, oxygen and oxygen-enriched air. Oxygen-enriched air may be, for example, a 50:50 by volume mix of air and oxygen. Other options are 1 :2 by volume mixtures of air and oxygen, 1 :3 by volume mixtures of air and oxygen, 2:1 by volume mixtures of air and oxygen, and 3:1 by volume mixtures of air and oxygen.

[0108] In one embodiment of the present invention, the inventive calcination is performed under a stream of gas, for example pure oxygen and oxygen-enriched air, for example in the range of from 3:1 to 10:1 oxygen : air by volume, determined at ambient temperature and ambient pressure. Such stream of gas may be termed a forced gas flow. Such stream of gas may have a specific flow rate in the range of from 0.5 to 15 m3 / h kg material according to general formula Lii+xTMi-xO2. The volume is determined under normal conditions: 298 Kelvin and 1 atmosphere. Said stream of gas is useful for removal of gaseous cleavage products such as water and carbon dioxide.

[0109] In one embodiment of the present invention, the inventive calcination has a duration in the range of from one hour to 30 hours. Preferred are 10 to 24 hours. The time at a temperature above 600°C is counted, heating and holding but the cooling time is neglected in this context.

[0110] A further aspect of the present invention relates to cathode active materials, hereinafter also referred to as inventive cathode active materials. Inventive cathode active materials may best be manufactured from inventive precursors. Inventive cathode active materials have the general formula Lii+XTM i.xC>2 with x being in the range of from -0.01 to + 0.07, preferably +0.01 to 0.04, and with a span of the particle diameter distribution (D90-D10) / D50, for example in the range of from 0.7 to 1.5. wherein TM comprises at least 80 mol-% nickel and at least one metal selected from cobalt and manganese, and wherein the particles are monolithic.

[0111] In this context, monolithic means that the crystallites of inventive cathode active materials are bigger than in cathode active materials that are agglomerates of primary particles. In one embodiment of the present invention, such crystallites have a diameter (D50) of 550 nm or more, e.g., 550 nm up to 5 pm when determined by SEM imaging. In such embodiments, the diameter may also be called “dimension”. Dimensions determined by SEM imaging usually adopt higher values than crystallite dimensions determined by X-ray diffraction.

[0112] In one embodiment of the present invention, the average diameter Dn50 as determined by light scattering (number based particle size distribution) is in the range of from 2.5 to 5.5 pm.

[0113] Monolithic particles are preferably irregular in shape. They may also be referred to as single crystalline.

[0114] In one embodiment of the present invention, inventive cathode material have an - outer - shell comprising at least one oxide compound of W or B or Co, for example, B2O3, Li BO2, U2WO4, WO3, CoO, CO3O4, or LiCoCh or the like. The second - outer - shell may be continuous or have an island structure. The amount of nickel then refers to the core, thus, without the shell. In other embodiments, inventive cathode active materials do not bear an outer shell comprising at least one oxide compound of W or B or Co.

[0115] In one embodiment of the present invention, inventive cathode active materials exhibit a disorder in the lithium layer in the range of from1.1 to 1.4%. Such disorder refers to nickel ions in the lithium layer and may be determined by Rietveld refinement. In a preferred embodiment, inventive cathode active materials do not bear an outer shell comprising at least one oxide compound of W or B or Co but do exhibit a disorder in the lithium layer in the range of froml .1 to 1.4%.

[0116] The span of inventive cathode active materials is above 0.60, for example in the range of from 0.7 to 1.5. The percentiles of D10, D90 and the median value are preferably determined by light scattering or LASER diffraction or electroacoustic spectroscopy, light scattering being preferred. In one embodiment of the present invention, inventive cathode active material has an average secondary particle diameter D50 in the range of from 2 to 8 pm, preferably 2 to 6 pm and even more preferably 2.5 to 5.5 pm.

[0117] In one embodiment of the present invention, TM is a combination of metals according to general formula (I)

[0118] (NiaCobMnc)i-dMd(I) with a being in the range of from 0.80 to 0.97, preferably from 0.83 to 0.95, b being zero or in the range of from 0.025 to 0.2, preferably from 0.025 to 0.15, c being in the range of from zero to 0.2, preferably from zero to 0.15, or from 0.01 to 0.15, and d being in the range of from zero to 0.1, preferably from 0.03 to 0.05,

[0119] M is selected from Ti, Zr, Mo, W, Al, Mg, Nb, Sb, and Ta, a + b + c = 1 , and b + c > zero.

[0120] Inventive cathode active materials are well suited for making lithium-ion batteries and especially cathodes for lithium-ion batteries.

[0121] A further aspect of the present invention refers to electrodes and specifically to cathodes, hereinafter also referred to as inventive cathodes. Inventive cathodes comprise

[0122] (A) at least one inventive cathode active material,

[0123] (B) carbon in electrically conductive form,

[0124] (C) at least one binder.

[0125] In a preferred embodiment of the present invention, inventive cathodes contain

[0126] (A) 80 to 99 % by weight inventive cathode active material,

[0127] (B) 0.5 to 19.5 % by weight of carbon,

[0128] (C) 0.5 to 9.5 % by weight of binder polymer, percentages referring to the sum of (A), (B) and (C).

[0129] Cathodes according to the present invention contain carbon in electrically conductive modification, in brief also referred to as carbon (B). Carbon (B) can be selected from soot, active carbon, carbon nanotubes, graphene, and graphite. Carbon (B) can be added as such during preparation of electrode materials according to the invention. Electrodes according to the present invention can comprise further components. They can comprise a current collector (D), such as, but not limited to, an aluminum foil. They further comprise a binder polymer (C), hereinafter also referred to as binder (C). Current collector (D) is not further described here.

[0130] 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, catalytic or free-radical (co)polymerization, especially 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 additionally suitable. Particular preference is given to polyacrylonitrile.

[0131] 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. Preference is given to polyacrylonitrile homopolymers.

[0132] In the context of the present invention, polyethylene is not only understood to mean homopolyethylene, but also copolymers of ethylene which comprise at least 50 mol% of copolymerized ethylene and up to 50 mol% of at least one further comonomer, for example a-olefins such as propylene, butylene (1 -butene), 1 -hexene, 1 -octene, 1 -decene, 1 -dodecene, 1 -pentene, and also isobutene, vinylaromatics, for example styrene, and also (meth)acrylic acid, vinyl acetate, vinyl propionate, Ci-C -alkyl esters of (meth)acrylic acid, especially methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-butyl acrylate, 2-ethylhexyl acrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate, and also maleic acid, maleic anhydride and itaconic anhydride. Polyethylene may be HDPE or LDPE.

[0133] In the context of the present invention, polypropylene is not only understood to mean homopolypropylene, but also copolymers of propylene which comprise at least 50 mol% of copolymerized propylene and up to 50 mol% of at least one further comonomer, for example ethylene and a- olefins such as butylene, 1 -hexene, 1 -octene, 1 -decene, 1 -dodecene and 1 -pentene. Polypropylene is preferably isotactic or essentially isotactic polypropylene.

[0134] In the context of the present invention, polystyrene is not only understood to mean homopolymers of styrene, but also copolymers with acrylonitrile, 1 ,3-butadiene, (meth)acrylic acid, Ci-Cw-alkyl esters of (meth)acrylic acid, divinylbenzene, especially 1 ,3-divinylbenzene, 1 ,2-diphenylethylene and a-methylstyrene. Another preferred binder (C) is polybutadiene.

[0135] Other suitable binders (C) are selected from polyethylene oxide (PEO), cellulose, carboxymethylcellulose, polyimides and polyvinyl alcohol.

[0136] In one embodiment of the present invention, binder (C) is selected from those (co)polymers which have an average molecular weight Mwin the range from 50,000 to 1,000,000 g / mol, preferably to 500,000 g / mol.

[0137] Binder (C) may be cross-linked or non-cross-linked (co)polymers.

[0138] In a particularly preferred embodiment of the present invention, binder (C) is selected from halogenated (co)polymers, especially from fluorinated (co)polymers. Halogenated or fluorinated (co)polymers are understood to mean those (co)polymers which comprise at least one (co)polymerized (co)monomer which has 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 are polyvinyl chloride, polyvinylidene chloride, polytetrafluoroethylene, polyvinylidene fluoride (PVdF), tetrafluoroethylene-hexafluoropropylene copolymers, vinylidene fluoride-hexafluoropropylene copolymers (PVdF-HFP), vinylidene fluoride-tetrafluoroethylene copolymers, perfluoroalkyl vinyl ether copolymers, ethylene-tetrafluoroethylene copolymers, vinylidene fluoride-chlorotrifluoroethylene copolymers and ethylene-chlorofluoroethylene copolymers.

[0139] Suitable binders (C) are especially polyvinyl alcohol and halogenated (co)polymers, for example polyvinyl chloride or polyvinylidene chloride, especially fluorinated (co)polymers such as polyvinyl fluoride and especially polyvinylidene fluoride and polytetrafluoroethylene.

[0140] A further aspect of the present invention is an electrochemical cell, containing

[0141] (A) a cathode comprising inventive cathode active material (A), carbon (B), and binder (C),

[0142] (B) an anode, and

[0143] (C) at least one electrolyte.

[0144] Embodiments of cathode (1) have been described above in detail.

[0145] Anode (2) may contain at least one anode active material, such as carbon (graphite), TiC>2, lithium titanium oxide, silicon or tin. Anode (2) may additionally contain a current collector, for example a metal foil such as a copper foil. Electrolyte (3) may comprise at least one non-aqueous solvent, at least one electrolyte salt and, optionally, additives.

[0146] Non-aqueous solvents for electrolyte (3) can be liquid or solid at room temperature and is preferably selected from among polymers, cyclic or acyclic ethers, cyclic and acyclic acetals and cyclic or acyclic organic carbonates.

[0147] Examples of suitable polymers are, in particular, polyalkylene glycols, preferably poly-Ci-C4- alkylene glycols and in particular polyethylene glycols. Polyethylene glycols can here comprise up to 20 mol% of one or more Ci-C4-alkylene glycols. Polyalkylene glycols are preferably polyalkylene glycols having two methyl or ethyl end caps.

[0148] The molecular weight Mwof suitable polyalkylene glycols and in particular suitable polyethylene glycols can be at least 400 g / mol.

[0149] The molecular weight Mwof suitable polyalkylene glycols and in particular suitable polyethylene glycols can be up to 5,000,000 g / mol, preferably up to 2,000,000 g / mol.

[0150] Examples of suitable acyclic ethers are, for example, diisopropyl ether, di-n-butyl ether, 1 ,2-dimethoxyethane, 1,2-diethoxyethane, with preference being given to 1,2-dimethoxyethane.

[0151] Examples of suitable cyclic ethers are tetrahydrofuran and 1,4-dioxane.

[0152] Examples of suitable acyclic acetals are, for example, dimethoxymethane, diethoxymethane, 1 ,1 -dimethoxyethane and 1,1 -diethoxyethane.

[0153] Examples of suitable cyclic acetals are 1,3-dioxane and, in particular, 1,3-dioxolane.

[0154] Examples of suitable acyclic organic carbonates are dimethyl carbonate, ethyl methyl carbonate and diethyl carbonate.

[0155] Examples of suitable cyclic organic carbonates are compounds of the general formulae (II) and (HI) where R1, R2and R3can be identical or different and are selected from among hydrogen and Ci-C4-alkyl, for example methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl and tertbutyl, with R2and R3preferably not both being tert-butyl.

[0156] In particularly preferred embodiments, R1is methyl and R2and R3are each hydrogen, or R1, R2and R3are each hydrogen.

[0157] Another preferred cyclic organic carbonate is vinylene carbonate, formula (IV).

[0158] The solvent or solvents is / are preferably used in the water-free state, i.e. with a water content in the range from 1 ppm to 0.1 % by weight, which can be determined, for example, by Karl-Fischer titration.

[0159] Electrolyte (3) further comprises at least one electrolyte salt. Suitable electrolyte salts are, in particular, lithium salts. Examples of suitable lithium salts are LiPFe, UBF4, l_iCIC>4, LiAsFe, UCF3SO3, LiC(CnF2n+iSO2)3, lithium imides such as LiN(CnF2n+iSO2)2, where n is an integer in the range from 1 to 20, LiN(SC>2F)2, Li2SiFe, LiSbFe, LiAICL and salts of the general formula (CnF2n+iSO2)tYLi, where m is defined as follows: t = 1 , when Y is selected from among oxygen and sulfur, t = 2, when Y is selected from among nitrogen and phosphorus, and t = 3, when Y is selected from among carbon and silicon.

[0160] Preferred electrolyte salts are selected from among LiC(CF3SO2)3, LiN(CF3SC>2)2, LiPFe, UBF4, LiCICL, with particular preference being given to LiPFe and LiN(CF3SC>2)2. In a preferred embodiment of the present invention, electrolyte (3) contains at least one flame retardant. Useful flame retardants may be selected from trialkyl phosphates, said alkyl being different or identical, triaryl phosphates, alkyl dialkyl phosphonates, and halogenated trialkyl phosphates. Preferred are tri-Ci-C4-alkyl phosphates, said Ci-C4-alkyls being different or identical, tribenzyl phosphate, triphenyl phosphate, Ci-C4-alkyl di- Ci-C4-alkyl phosphonates, and fluorinated tri-Ci-C4-alkyl phosphates,

[0161] In a preferred embodiment, electrolyte (3) comprises at least one flame retardant selected from trimethyl phosphate, CH3- (O)(OCH3)2, triphenylphosphate, and tris-(2,2,2-trifluoroethyl)- phosphate.

[0162] Electrolyte (3) may contain 1 to 10% by weight of flame retardant, based on the total amount of electrolyte.

[0163] In an embodiment of the present invention, batteries according to the invention comprise one or more separators (4) by means of which the electrodes are mechanically separated. Suitable separators (4) are polymer films, in particular porous polymer films, which are unreactive toward metallic lithium. Particularly suitable materials for separators (4) are polyolefins, in particular film-forming porous polyethylene and film-forming porous polypropylene.

[0164] Separators (4) composed of polyolefin, in particular polyethylene or polypropylene, can have a porosity in the range from 35 to 50%. Suitable pore diameters are, for example, in the range from 30 to 500 nm.

[0165] In another embodiment of the present invention, separators (4) can be selected from among PET nonwovens filled with inorganic particles. Such separators can have a porosity in the range from 40 to 55%. Suitable pore diameters are, for example, in the range from 80 to 750 nm.

[0166] Batteries according to the invention can further comprise a housing which can have any shape, for example cuboidal or the shape of a cylindrical disk. In one variant, a metal foil configured as a pouch is used as housing.

[0167] Batteries according to the invention provide a very good discharge and cycling behavior, in particular at high temperatures (45 °C or higher, for example up to 60°C) in particular with respect to the capacity loss.

[0168] Batteries according to the invention can comprise two or more electrochemical cells that combined with one another, for example can be connected in series or connected in parallel. Connection in series is preferred. In batteries according to the present invention, at least one of the electrochemical cells contains at least one electrode according to the invention. Preferably, in electrochemical cells according to the present invention, the majority of the electrochemical cells contain an electrode according to the present invention. Even more preferably, in batteries according to the present invention all the electrochemical cells contain electrodes according to the present invention.

[0169] The present invention further provides for the use of batteries according to the invention in appliances, in particular in mobile appliances. Examples of mobile appliances are vehicles, for example automobiles, bicycles, aircraft or water vehicles such as boats or ships. Other examples of mobile appliances are those which move manually, for example computers, especially laptops, telephones or electric hand tools, for example in the building sector, especially drills, battery-powered screwdrivers or battery-powered staplers.

[0170] The invention is further illustrated by working examples and drawings.

[0171] General remarks:

[0172] A cascade of two 3.2-liter stirred tank reactors made of glass and each equipped with baffles and a two-stage stirrer, each comprising one four-bladed pitch-blade turbine (45° angle, diameter: 0.08 m) and a Rushton turbine, diameter 0.08 m, was used for the experimental examples. Each stirred tank reactor was furthermore equipped with a settling device via which mother liquor was withdrawn from the reactors, and an overflow.

[0173] All pH values were determined at 23°C. rpm: revolutions per minute

[0174] Total solids contents were determined by H2SO4 dissolution of an aliquot of the respective suspension and subsequent ICP analysis of Ni, Co, Mn

[0175] Figure 1: cascade of two stirred tank reactors, each equipped with overflow systems, clarifiers, baffles, and with two buffer tanks

[0176] Figure 2: cascade of two stirred tank reactors, each equipped with overflow systems, baffles, and with two buffer tanks. The second stirred tank reactor is equipped with a clarifier, the first is not.

[0177] I. Manufacture of precursors

[0178] 1.1 Manufacture of inventive (oxy) hydroxide P-CAM.1 and of dehydrated Oxy-P-CAM.1

[0179] Step (a.1):

[0180] The following aqueous solutions were provided: Solution (a1.1): NiSCU, CoSO4 and MnSC>4 dissolved in deionized water, molar ratio 93.5:4.5:2.0, total transition metal concentration: 1.45 mol / kg

[0181] Solution (pi .1): 25wt% NaOH dissolved in deionized water Solution (y1.1): 25wt% ammonia in deionized water

[0182] Percentages refer to % by weight unless expressly noted otherwise.

[0183] Prior to step (b.1)

[0184] The first stirred tank reactor of the cascade was charged with 2.7 liters of deionized water and heated to 45°C under stirring with 500 rpm (average specific energy input: 400 W / kg).

[0185] Step (b.1):

[0186] Subsequently, the stirrer speed was adjusted to 1200 rpm (560 W / kg) and the simultaneous feeding of solutions (a1.1), ( 1.1) and (y1.1) was started. The stirrer speed was kept constant during step (b.1). The total flow rate was adjusted in a way that the ratio between reactor volume (3.2 I) and total volume flow amounted to 10 hours (residence time equivalent). The temperature was remained constant at 45°C. The molar feed ratio between ammonia and TM was set to 0.25 and was kept constant during step (b.1). The pH value was adjusted to 11.5.

[0187] When the reactor had reached the steady state the overflow was collected in a suspension buffer tank. The suspension contained slurried particles with an average particle size (d50) of 1 to 2 pm and with a span of 1.26.

[0188] Step (c.1 )

[0189] The second reactor of the cascade was charged with 1.2 I of the suspension made in step (b.1) heated to 45°C under stirring (1200 rpm, specific energy input: 560 W / kg). The solids content at the beginning of step (e.1 ) equals that of the suspension collected in (b.1).

[0190] Step (d.1):

[0191] The following aqueous solutions were provided:

[0192] Solution (a2.1): NiSCU, COSO4 and MnSC>4 dissolved in deionized water, molar ratio 93.5:4.5:2.0, total transition metal concentration: 1.45 mol / kg

[0193] Solution (p2.1 ): 25wt% NaOH dissolved in deionized water Solution (y2.1 ): 25wt% ammonia in deionized water

[0194] Step (e.1 ) Subsequently, the simultaneous feeding of solutions (a2.1), (p2.1), and (y2.1) was started. The molar feed ratio between ammonia and TM was set to 0.12 and was kept constant. The temperature was remained constant at 45°C during step (e). The pH value was adjusted to 12.0 and then maintained constant at this value until the end of step (e.1). The ratio between reactor volume (3.2 liter) and total volume flow of the feeds (residence time equivalent) was kept constant within 5 hours. The rotation speed of the stirrer was stepwise decreased during the batch to a final stirrer speed of 800 rpm (165 W / kg). Mother liquor was continuously withdrawn from the tank reactor to increase the solids content. The complete duration of step (e.1) was 25 hours and resulted in a slurry with a total solids content in the reactor of 304 g / l. After completion of the batch all feed flows were stopped and the resultant suspension from reactor and clarifier were discharged to a stirred suspension buffer vessel. The particles in said suspension had an average particle size (d50) of 3.3 pm and a span of 0.91.

[0195] Work-up:

[0196] The slurry from step (e.1) was filtered. The resulting filter cake was washed with deionized water and then with an aqueous solution of sodium hydroxide (1 kg of 25 wt% aqueous sodium hydroxide solution per kg of solid hydroxide).

[0197] The filter cake was dried at 120°C over a period of 12 hours in a cabinet dryer to obtain mixed metal (oxy)hydroxide P-CAM.1. P-CAM.1 was an (oxy) hydroxi de of TM, with a: 0.935, b = 0.045, c = 0.02, d = zero, an average particle diameter (D50) of 3.3 pm, a span of 0.91 , and a BET surface area of 6.5 m2 / g. The average form factor amounted to 0.991.

[0198] 1.2 Manufacture of a comparative (oxy)hydroxide C-P-CAM.1

[0199] Steps (a.1) as well as the step prior to (b1.) was repeated.

[0200] Step C-(b.2) Subsequently, the simultaneous feeding of solutions (a2.1), (p2.1), and (y2.1) was started. The molar feed ratio between ammonia and TM was set to 0.25 and was kept constant. The temperature was remained constant at 55°C during step C-(b.2). The pH value was adjusted to 12.5 and after two minutes reduced to 12.0 and then kept constant through the end of step C- (b.2). The stirring speed was adjusted to 1200 rpm (560 W / kg). The ratio between reactor volume (3.2 liter) and total volume flow of the feeds (residence time equivalent) corresponded to a residence time equivalent of 15 hours. The rotation speed of the stirrer was stepwise decreased during the batch to a final stirrer speed of 800 rpm (165 W / kg). Mother liquor was continuously withdrawn from the tank reactor to increase the solids content. The complete duration of step C-(b.2) was 40 hours and resulted in a slurry with a total solids content in the reactor of 400 g / l. After completion of the batch all feed flows were stopped and the final suspension from reactor and clarifier was discharged to a stirred suspension buffer vessel. The particles in the suspension had an average particle size (D50) of 3.3 pm with a span of 0.74.

[0201] Neither step (f) nor (g) was performed.

[0202] Work-up:

[0203] The slurry from step C-(b.2) was filtered. The resulting filter cake was washed with deionized water and then with an aqueous solution of sodium hydroxide (1 kg of 25 wt% aqueous sodium hydroxide solution per kg of solid hydroxide).

[0204] The filter cake was dried at 120°C over a period of 12 hours in a cabinet dryer to obtain mixed metal (oxy)hydroxide C-P-CAM.2. C-P-CAM.2 had an average particle diameter (D50) of 3.7 pm, a span of 0.74, and a BET surface area of 9.2 m2 / g. The average form factor amounted to 0.89.

[0205] Table 1 summarizes the properties of the inventive and of the comparative precursors.

[0206] Table 1 : Inventive and comparative precursors

[0207] Table 1 (continued): XRD properties of the inventive and comparative precursors

[0208] II. Manufacture of inventive and comparative cathode material

[0209] 11.1 Calcination and post-treatments of an inventive precursor

[0210] 30 g of P-CAM.1 was mixed with LiOH monohydrate (molar ratio Li / metal = 1.05) and 153 mg ZrC>2 in an acoustic mixer. A saggar was charged with the resultant mixture and transferred into a Linn oven. The calcination was performed in oxygen atmosphere and using a two-temperature calcination profile. At a heating rate of 3 C / min the first step at 500 °C was held constant for 3 hours and the second step at 800°C for 12 hours, and the calcined material was subsequently allowed to naturally cool under flowing oxygen. The resultant powder was then deagglomerated in a ball mill. 20 g of the resultant powder were mixed with 35 g of 10 mm agate balls and 10 mL of water in an 80 mL agate ball mill container and milled for 60 min at 300 rpm. The resulting dispersion was dried under vacuum overnight and calcined at 700°C for 2h. After sieving using a 32 pm mesh, CAM.1 was obtained. When assessed through SEM imaging, the particles of CAM.1 were monolithic and had a low tendency of fines formation. The composition corresponded to the formula Lii.o(Nio.932Coo.o44Mno.o2oZro.oo4)02.

[0211] I I.2 Manufacture of a comparative cathode active material

[0212] The comparative C-P-CAM.2 was treated in the same way and C-CAM.2 was obtained. The share of fines was higher than in the case of the inventive cathode active material CAM.1.

[0213] III. T esting of Cathode Active Material

[0214] 111.1 Electrolyte Manufacture

[0215] Positive electrode tape: PVDF binder (polyvinylidene difluoride, Solef® 5130) was dissolved in NMP (Merck) to produce a 7.5 wt.% solution. For electrode preparation, binder solution (3 wt.%) and carbon black (Super C65, 3 wt.-%) were suspended in NMP. After mixing using an acoustic mixer (LabRAM II, Resodyn Corp., USA), either inventive CAM.1 or C-CAM.2 (94 wt.%) was added and the suspension was mixed again to obtain a lump-free slurry. The solids content of the slurry was adjusted to 55%. The slurry was coated onto Al foil using a film applicator Model 510 Basic-G (ERICHSEN GmbH & Co. KG, Germany). Prior to use, all electrodes were calendared. The thickness of cathode material was 50 pm, corresponding to 16 mg / cm2.

[0216] 111.2 Electrolyte Manufacture

[0217] A base electrolyte composition was prepared containing 11.8 wt% of LiPFe, 44.1 wt% of ethylene carbonate (EC), and 44.1 wt% of dimethyl carbonate (DMC) (EL base 1), based on the total weight of EL base 1.

[0218] 111.3 Test cell Manufacture - coin type half cells

[0219] Coin-type half cells (20 mm in diameter and 3.2 mm in thickness) comprising a cathode prepared as described under 11.1.1 and lithium metal as working and counter electrode, respectively, were assembled and sealed in an Ar-filled glove box. In addition, the cathode and anode and a separator were superposed in order of cathode / / separator / / Li foil to produce a half coin cell. Thereafter, 0.15 mL of the EL base 1 which is described above (111.2) were introduced into the coin cell. 111.4 Evaluation of cell performance

[0220] The initial performance, C-rate performance and cycling performance were measured as follows: Coin half cells according to 11.3 were tested in a voltage range between 4.3 V to 2.7 V at 25 °C. For the initial cycles, the initial delithiation of CAM was conducted in the CC-CV mode, i.e. , a constant current (CC) of 0.05 C was applied until reaching 4.3V, followed by the CV step until the current dropped to 0.02 C. After 5 min resting time, discharge was carried out at constant current of 0.05 C to 2.7 V. For the C-rate test charge and discharge rates were adjusted accordingly. For the cycling test, the constant current was chosen to be 1 / 3 C until 56 cycles were reached. The results are summarized in Table 2.

[0221] Table 2: Physical data of cathode active materials

[0222] Electrochemical cells containing CAM.1 are more stable with respect to cycling in comparison to analogous cells containing C-CAM.2.

Claims

Patent Claims1. Process for making a particulate (oxy)hydroxide or oxide of TM wherein TM is a combination of metals according to general formula (I)(NiaCobMnc)i-dMd(I) with a being in the range of from 0.80 to 0.97, b being zero or in the range of from 0.025 to 0.2, c being in the range of from zero to 0.2, and d being in the range of from zero to 0.1 ,M is selected from Mg, Al, Ti, Zr, Mo, W, Nb, Sb, and Ta, a + b + c = 1 , and b + c > zero, wherein said process is performed in a cascade of at least two stirred tank reactors and comprises the steps of:(a) providing an aqueous solution (a1) containing a water-soluble salt of Ni and, optionally, at least one metal selected from cobalt and manganese, and an aqueous solution (pi) containing an alkali metal hydroxide and, optionally, an aqueous solution (y1) containing a complexing agent selected from ammonia, glycine, tartrate, citrate, and oxalate,(b) combining, in a continuous stirred tank reactor, solution (cd) and solution (pi) and, if applicable, solution (y1), at a pH value in the range of from 11.0 to 13.5, thereby creating slurried solid particles of a hydroxide of TM with an average diameter (D50) in the range of from 1 to 2 pm,(c) transferring the particles from step (b) as a slurry into a second stirred tank reactor that is operated as a batch reactor,(d) providing an aqueous solution (a2) containing a water-soluble salt of Ni and of at least one metal selected from cobalt and manganese, and an aqueous solution (P2) containing an alkali metal hydroxide and, optionally, an aqueous solution (y2) containing a complexing agent selected from ammonia, glycine, tartrate, citrate, and oxalate,(e) combining solution (a2) and solution (P2) and, if applicable, solution (y2), in said second stirred tank reactor at a pH value in the range of from 10.5 to 13.0 and with an average specific energy input in the range of from 140 to 600 W / kg, thereby growing the solid particles of a hydroxide of TM.

2. Process according to claim 1 wherein the initial solids content at stage start increases from step (b) to step (e).

3. Process according to claim 1 or 2 wherein in steps (b) and (e), mother liquor is withdrawn from the tank reactors.

4. Process according to any of the preceding claims comprising an additional step (f) of separating particulate (oxy)hydroxide by a solid-liquid separation method and subsequent drying.

5. Process according to claim 4 wherein said process comprises a subsequent heating step (g) at a temperature in the range of from 400 to 550°C in the absence of a lithium compound.

6. Particulate (oxy)hydroxide of TM with a span of the particle diameter distribution (D90- D10) / D50 from 0.55 to 0.95, determined by light scattering, wherein TM is a combination of metals according to general formula (I)(NiaCobMnc)i-dMd(I) with a being in the range of from 0.80 to 0.97, b being zero or in the range of from 0.025 to 0.2, c being in the range of from zero to 0.2, and d being in the range of from zero to 0.1 ,M is selected from Mg, Al, Ti, Zr, Mo, W, Nb, Sb, and Ta, a + b + c = 1 , and b + c > zero, and wherein the particles are composed of primary particles and have a core and shell and a concentric layer between core and shell wherein the density of the concentric layer is higher than the density of the core and of the shell.

7. Particulate (oxy)hydroxide of TO according to claim 6 wherein its particles are composed of primary particles, and wherein said particulate oxide has a ratio of the FWHM values of the following reflections determined by XRD analysis: (001 ) / (101 ) is from 0.75 to 0.90 A and (001) / (100) is from 1.95 to 2.25, and having an absolute crystallite sizes according to the Debye Scherrer equation in the range of 90 to 105 A for the (001) reflection, 195 to 220 A for the (100) reflection and 70 to 85 A for the (101) reflection.

8. Particulate oxide of TM with a span of the particle diameter distribution (D90-D10) / D50 of 0.55 to 0.95, determined by light scattering, wherein TM is a combination of metals according to general formula (I)(NiaCobMnc)i-dMd(I) with a being in the range of from 0.80 to 0.97, b being zero or in the range of from 0.025 to 0.2, c being in the range of from zero to 0.2, and d being in the range of from zero to 0.1 ,M is selected from Mg, Al, Ti, Zr, Mo, W, Nb, Sb, and Ta, a + b + c = 1 , and b + c > zero, and wherein the particles are composed of primary particles, and wherein said particulate oxide has a ratio of the FWHM values of the following reflections determined by XRD analysis: (001) / (101) is from 0.75 to 0.90 A and (001) / (100) is from 1.95 to 2.25, and having an absolute crystallite sizes according to the Debye Scherrer equation in the range of 90 to 105 A for the (001) reflection, 195 to 220 A for the (100) reflection and 70 to 85 A for the (101) reflection.

9. Particulate (ox)hydroxide according to claim 6 or 7 or oxide according to claim 8 having a specific surface according to BET in the range of from 2 to 120 m2 / g.

10. Particulate (ox)hydroxide or oxide according to any of claims 6 to 9 having an average form factor of 0.90 or more.

11. Process for the manufacture of cathode active materials for lithium-ion batteries comprising the steps of mixing a particulate (ox)hydroxide or oxide according to any of theclaims 8 to 10 with a source of lithium and, optionally, a dopant selected from an oxide or (oxy)hydroxide of Nb, Ti, Ta, Zr, Al, Mg, or W, and calcining the resultant mixture at a temperature in the range of from 750 to 900°C.

12. Cathode active material of the general formula Lii+xTMi-xO2 with x being in the range of from -0.01 to + 0.05 and a span of the particle diameter distribution (D90-D10) / D50 from 0.7 to 1.5, wherein TM is a combination of metals according to general formula (I) ,(NiaCobMnc)i-dMd(I) with a being in the range of from 0.80 to 0.97, b being zero or in the range of from 0.025 to 0.2, c being in the range of from zero to 0.2, and d being in the range of from zero to 0.1 ,M is selected from Mg, Al, Ti, Zr, Mo, W, Nb, Sb, and Ta, a + b + c = 1 , and b + c > zero, and wherein the particles are monolithic, and wherein such cathode active materials exhibit a disorder in the lithium layer in the range of from 1.1 to 1.4%, as determined by Rietveld refinement.

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