WO2026008399A1

WO2026008399A1 - Process for making a particulate (oxy)hydroxide or oxide, particulate (oxy)hydroxide and use

Info

Publication number: WO2026008399A1
Application number: PCT/EP2025/067803
Authority: WO
Inventors: Joop Enno FRERICHS; Maike WIRTZ; Balazs Barnabas BERKES; Kathrin Michel; Rafael Benjamin BERK
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 2024-07-01
Filing date: 2025-06-24
Publication date: 2026-01-08
Anticipated expiration: 2027-01-01

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 two stirred tank reactors.

Description

PROCESS FOR MAKING A PARTICULATE (OXY)HYDROXIDE OR OXIDE, PARTICULATE (OXY)HYDROXIDE AND USE

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 is at least 80 mol-%, wherein said process is performed in a cascade of two stirred tank reactors and comprises the steps of:

(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,

(b) combining, in a continuous stirred tank reactor, solution (a1) 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 2 to 4 pm,

(c) transferring particles from step (b) as a slurry into a second stirred tank reactor that is operated in the batch mode and adjusting the solids content to 25 to 35 g/l,

(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,

(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, thereby growing the solid particles of a hydroxide of TM, with a growth rate of 0.40 pm/h or less. Step (e) may be performed once or repeatedly.

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.

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.

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.

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 CN 112591807 A, a multi-stage co-precipitation process is disclosed that yields high-density precursors.

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 narrow particle size distribution and a low tendency of agglomerate formation.

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.

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), hereinafter also referred to as step (a) and step (b) and step (c) and step (d) and step (e), or briefly as (a) or (b) or (c) or (d) or (e), respectively. The inventive process will be described in more detail below.

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, light scattering eing 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.

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%.

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

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)hydroxide of TM wherein TM comprises Ni and, optionally, 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, wherein the nickel content of TM is at least 80 mol- %. Preferably, the precursor comprises nickel and at least one metal selected from Co and Mn, more preferably, said precursor comprise nickel and cobalt and manganese. 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.

TM is a combination of metals according to general formula (I)

(Ni_aCo_bMn_c)i-_dM_d (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,

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

Preferably, d = zero.

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.

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.

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.

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.

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.

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).

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.

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.

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.

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.

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.

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

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.

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 2 to 4 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.

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.

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.

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.

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

Step (b) is performed in a continuous stirred tank reactor (“CSTR”). A CSTR is usually equipped with an overflow. In step (b), preferably a slurry with particles with an average diameter (D50) in the range of from 3 to 5 pm are 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.

In on embodiment of the present invention, the solids content of slurry removed from step (b) is in the range of from 200 to 400 g/l. The solids content is determined by dissolving the precipitate in sulfuric acid and determining the metal content by IC (Inductively Coupled Plasma).

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, an average residence time of 10 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.

In step (c), the particles from step (b) are transferred as a slurry into a second stirred tank reactor, and the solids content in the second stirred tank reactor is adjusted to 25 to 35 g/l. 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, and the solids content refers to the specific stirred tank reactor.

Said transfer may be performed intermittently or continuously.

The solids content of to 25 to 35 g/l refers to the end of step (c) and to the beginning of step (e).

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.

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. 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.

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

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.

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).

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.

In step (d), 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.

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

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).

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

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

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

The growth rate in step (e) is 0.40 pm/h or less. This means that essentially at each time of step (e), the diameter of the precipitated particles grows by 0.40 pm/h or less, preferably by 0.3 pm/h or less. Unintended peaks above 0.4 pm/h that last for 5 minutes or less are not prejudicial if the average growth rate is below 0.40 pm/h. Preferably, the minimum growth rate is 0.1 pm/h.

In one embodiment of the present invention, the average particle diameter (D50) of (oxy)hydroxide obtained at the end of step (e) is in the range of from 13 to 20 pm, determined by light scattering and referring to the volume-based average.

The growth rate may be steered by the speed of addition of aqueous solution (a2) and solution (P2) and, if applicable, solution (y2).

In the course of step (e), the rate (speed) of addition of aqueous solution (a2) and solution (P2) and, if applicable, solution (y2) increases, preferably exponentially.

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.

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.

In one embodiment of step (e), an average specific energy input of from 5 to 300 W/kg is introduced, 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. In one embodiment of the present invention, the average particle diameter of (oxy)hydroxide made in step (e) is in the range of from 13 to 20 pm but in any case bigger than at the end of step (b) and of step (c).

In one embodiment of the present invention, the solids content at the end of step (e) is in the range of from 600 to 1200 g/l.

In one embodiment of the present invention, step (e) has a duration in the range of from 25 to 50, preferably 35 to 46 hours.

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.

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, 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.

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.

Step (e) may be performed once or repeatedly.

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

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.

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.

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

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.

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 0.40, preferably from 0.20 to 0.35, more preferably 0.20 to 0.30, 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.

Another embodiment of inventive precursors are particulate oxides of TM with a span of the particle diameter distribution (D90-D10)/D50 below 0.40, preferably from 0.20 to 0.35, more preferably 0.20 to 0.30, wherein TM comprises nickel and at least one metal selected from cobalt and manganese, and wherein the particles are composed of primary particles.

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

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, light scattering being preferred.

In SEM imaging analyses of cross-sections of inventive precursors, essentially no amorphous regions may be detected. The term “essentially no amorphous regions” refers to a share of less than 5 parts of the cross-sections of 10 randomly picked particles. Preferably, no amorphous shells or rings or other concentric amorphous layers that may encapsule the core may be detected. More preferably, no amorphous regions may be detected at all.

TM is defined as outlined above.

Inventive particulate (oxy)hydroxide of TM may exhibit FWHM values of the following reflections determined by XRD analysis: (001) in the range from 0.25 to 0.37 when determined with Mo-Ka radiation.

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 13.0 to 20 pm, preferably 13.0 to 14.0 pm and more preferably 14.0 to 15.0 pm.

TM is a combination of metals according to general formula (I)

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

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. 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.

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.

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 at least 80% and even more preferably the entire volume. 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. Even more preferably, virtually no random oriented primary particles may be detected.

In one embodiment of the present invention, inventive oxide precursor has an average secondary particle diameter D50 in the range of from 12.0 to 20.0 pm, preferably 14.0 to 15.0 pm. The values refer to the volume-based average and are preferably determined by light scattering.

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.

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. Preferably, the entirety of the secondary particles consists of primary particles that are radially oriented or display a maximum deviation to a perfectly radial orientation of 11 degrees

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

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

Form factor = (4TT area)/(perimeter)²

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 for the 90% of the most spherical particles. This is why it may be referred to as average form factor as well.

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.

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. 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.

Examples of inventive calcinations include heat treatment at a temperature in the range of from 600 to 900°C, preferably 650 to 850°C. The terms “treating thermally” and “heat treatment” are used interchangeably in the context of the present invention.

In one embodiment of the present invention, the mixture obtained for the inventive calcination is heated to 600 to 900 °C with a heating rate of 0.1 to 10 °C/min.

In one embodiment of the present invention, the temperature is ramped up before reaching the desired temperature of from 600 to 900°C, preferably 650 to 800°C. 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 650°C up to 800°C and then held at 650 to 800 for 10 minutes to 10 hours.

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.

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.

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.

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.

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._xO2 with x being in the range of from -0.01 to + 0.05, preferably +0.01 to 0.04, and with a span of the particle diameter distribution (D90-D10)/D50 being 0.30 or less, for example in the range of from 0.20 to 0.30, wherein TM comprises at least 80 mol-% nickel and at least one metal selected from cobalt and manganese.

In one embodiment of the present invention, inventive cathode material have a- 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.

The span of inventive cathode active materials is below 0.30, for example in the range of from 0.20 to 0.30. 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 13.0 to 20.0 pm, preferably 13.0 to 14.0 pm and even more preferably 14.0 to 15.0 pm.

TM is a combination of metals according to general formula (I)

(Ni_aCo_bMn_c)i-_dM_d (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,

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

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

(A) at least one inventive cathode active material,

(B) carbon in electrically conductive form,

(C) at least one binder.

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

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

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

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

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.

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.

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.

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.

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.

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.

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

In one embodiment of the present invention, binder (C) is selected from those (co)polymers which have an average molecular weight M_w in the range from 50,000 to 1 ,000,000 g/mol, preferably to 500,000 g/mol. Binder (C) may be cross-linked or non-cross-linked (co)polymers.

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.

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.

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

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

(B) an anode, and

(C) at least one electrolyte.

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

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.

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. 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.

The molecular weight M_w of suitable polyalkylene glycols and in particular suitable polyethylene glycols can be at least 400 g/mol.

The molecular weight M_w of 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.

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.

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

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

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

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

Examples of suitable cyclic organic carbonates are compounds of the general formulae (II) and (HI) where R¹, R² and R³ can 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 R² and R³ preferably not both being tert-butyl. In particularly preferred embodiments, R¹ is methyl and R² and R³ are each hydrogen, or R¹, R² and R³ are each hydrogen.

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

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.

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(C_nF2n+iSO2)3, lithium imides such as LiN(C_nF2n+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 (C_nF2n+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.

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,

In a preferred embodiment, electrolyte (3) comprises at least one flame retardant selected from trimethyl phosphate, CH3-P(O)(OCH3)2, triphenylphosphate, and tris-(2,2,2-trifluoroethyl)- phosphate. Electrolyte (3) may contain 1 to 10% by weight of flame retardant, based on the total amount of electrolyte.

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.

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.

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.

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.

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.

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.

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.

The invention is further illustrated by working examples and drawings.

General remarks:

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.

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

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

I. Manufacture of precursors

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

Step (a.1):

The following aqueous solutions were provided:

Solution (a1.1): NiSCU, COSO4 and MnSC>4 dissolved in deionized water, molar ratio 91.0 : 4.5 : 4.5, total transition metal concentration: 1.45 mol/kg

Solution (pi .1): 25wt% NaOH dissolved in deionized water

Solution (y1 .1): 25wt% ammonia in deionized water

Percentages refer to % by weight unless expressly noted otherwise.

Prior to step (b.1)

The first stirred tank reactor of the cascade was charged with 3.2 liters of deionized water and heated to 45°C under stirring with 500 rpm (average specific energy input: 40 W/kg).

Step (b.1):

Subsequently, the stirrer speed was adjusted to 1200 rpm (560 W/kg) and the simultaneous feeding of solutions (a1.1), (P1.1) 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 of NH3 was set to account in 0.50 wt% in the particle free mother liquor, during step (b.1). After a time of 2 min at pH value of 12.5 the pH value was adjusted to 11.4 for rest of step (b.1). Over the course of the reaction the stirring energy input was adjusted in a stepwise manner to 800 rpm (165 w/kg) and the precipitation was stopped when the particle diameter (D50) had reached 4.0 pm.

Step (c.1 )

The second reactor of the cascade was charged with 2.6 I of de-ionized water before ( 1.1) and (y1.1) were added accordingly to adjust the precipitation conditions. Then, the suspension made in step (b.1) was added and the reactor content was heated to 65°C under stirring (950 rpm, specific energy input: 280 W/kg). The solids content in step (c.1) - which corresponds to the beginning of step (e.1) - was adjusted to equal 25.5 g/l. Over the course of the reaction the stirring energy was adjusted accordingly.

Step (d.1):

The following aqueous solutions were provided:

Solution (a2.1): NiSO4, COSO4 and MnSO4 dissolved in deionized water, molar ratio 93.5:4.5:2.0, total transition metal concentration: 1.45 mol/kg

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

Step (e.1 ) Subsequently, the simultaneous feeding of solutions (a2.1), (p2.1), and (y2.1) was started. The molar feed was set to account for 0.50 wt% in the particle free mother liquor. The temperature was kept constant at 65°C during step (e.1 ) . The pH value was adjusted to 11.4 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 250 rpm (21 W/kg). Mother liquor was continuously withdrawn from the tank reactor to increase the solids content. The complete duration of step (e.1 ) was 46 hours and resulted in a slurry with a total solids content in the reactor of 1140 g/l. The growth rate was 0.23 pm/h. 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. Work-up:

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).

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 had an average particle diameter (D50) of 14.5 pm, a span of 0.25, and a BET surface area of 8.6 m²/g. The average form factor (percentile 90) amounted to 0.9921.

Oxy-P-CAM.1

Inventive P-CAM.1 was heated in a Linn oven for 2 hours at 450°C under flowing air to obtain mixed metal oxide oxy-P-CAM.1. The inventive Oxy-P-CAM.1 had an average particle diameter (D50) of 14.3 pm, a span of 0.23 and BET surface area of 97.6 m²/g.

1.2 Manufacture of a comparative (oxy)hydroxide C-P-CAM.1 and of comparative dehydrated oxy-C-P-CAM.1

Steps (a.1), (b.1 , (c.1 and (d.1) were repeated.

Step C-(e.2)

Subsequently, the simultaneous feeding of solutions (a2.1), (p2.1), and (y2.1) was started. The molar feeds were set to account for 0.50 wt% in the particle free mother liquor. The temperature was remained constant at 65°C during step C-(e.2). The pH value was adjusted to 11.5 and then maintained constant at this value until the end of step C-(e.2). 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 250 rpm (21 W/kg). Mother liquor was continuously withdrawn from the tank reactor to increase the solids content. The complete duration of step C-(e.2) was 17 hours and resulted in a slurry with a total solids content in the reactor of 400 g/l. The growth rate was 0.69 pm/h. 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. Work-up:

The slurry from step C-(e.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).

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 13.7 pm, a span of 0.33, and a BET surface area of 10.2 m²/g. The average form factor (percentile 90) amounted to 0.9916.

Oxy-C-P-CAM.2

C-P-CAM.2 was heated in a Linn oven for 2 hours at 450°C under flowing air to obtain mixed metal oxide Oxy-P-CAM.2. The comparative precursor Oxy-P-CAM.2 was obtained.

Table 1 summarizes the properties of the inventive and of the comparative precursors. SEM images are summarized under Figure 1.

Table 1 : inventive and comparative precursors

Diameters were obtained by light scattering.

Table 1 (continued): XRD properties of inventive and comparative precursors (Mo-Ka radiation)

II. Manufacture of inventive and comparative cathode material

11.1 Calcination and post-treatments of an inventive precursor

80 g of oxy-P-CAM.1 was mixed with LiOH monohydrate (molar ratio Li/TM = 1.04), 489 mg AI((OH)3 and 406 mg ZrC>2 for 15 minutes in a grinding mill. A saggar was charged with the resultant mixture and transferred into a Linn oven. The temperature was raised at rate of 2 C/min to 765 °C under flowing oxygen and then held constant at 765 °C for 8 hours and subsequently allowed to naturally cool under flowing oxygen. The resultant powder was then deagglomerated in a grinding mill and sieved.

80 g powder was then added to 40 ml deionized water, stirred for 2 minutes and then immediately filtered on a Buchner funnel to remove water. The wet filter cake was then dried under an N2 atmosphere with reduced pressure at 120 °C for 10 hours.

The resultant powder was then dry coated with boric acid by mixing 80 g powder, mixing media and 80 mg boric acid for 40 minutes at low speed on a roller mill. A saggar was charged with the dried powder and heat treated in Linn oven. The Linn oven was heated to 300 °C for 3 hours under oxygen atmosphere and allowed to cool naturally. Inventive CAM.1 was obtained.

I I.2 Manufacture of a comparative cathode active material

The comparative oxide Oxy-C-P-CAM.2 was treated in the same way and C-CAM.2 was obtained with a (D50) of 14.0 pm, a span of 0.34 and an average form factor of 0.975.

III. T esting of Cathode Active Material

111.1 Electrolyte Manufacture

Positive electrode: 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.%), graphite (SFG6L, 2 wt.%), and carbon black (Super C65, 1 wt.-%) were suspended in NMP. After mixing using a planetary centrifugal mixer (ARE-250, Thinky Corp., Japan), either inventive CAM.1 or C-CAM.2 (94 wt.%) was added and the suspension was stirred again to obtain a lump-free slurry. The solids content of the slurry was adjusted to 65%. The slurry was coated onto Al foil using a KTF-S roll-to-roll coater (Mathis AG). Prior to use, all electrodes were calendared. The thickness of cathode material was 70 pm, corresponding to 15 mg/cm². All electrodes were dried at 105°C for 7 hours before battery assembly.

111.2 Electrolyte Manufacture

A base electrolyte composition was prepared containing 12.7 wt% of LiPFe, 26.2 wt% of ethylene carbonate (EC), and 61.1 wt% of ethyl methyl carbonate (EMC) (EL base 1), based on the total weight of EL base 1. To this base electrolyte formulation 2wt.% of vinylene carbonate (VC) was added (EL base 2). III.3 Test cell Manufacture - coin type half cells

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

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 2.8 V at room temperature. For the initial cycles, the initial lithiation was conducted in the CC-CV mode, i.e. , a constant current (CC) of 0.1 C was applied until reaching 4.3V, followed by the CV step until the current dropped to 0.01 C. After 10 min resting time, reductive lithiation was carried out at constant current of 0.1 C up to 2.8 V. For the C-rate test charge and discharge rates were adjusted accordingly. For the cycling test, the constant current was chosen to be 1C until 100 cycles were reached.

Electrochemical cells based on CAM.1 were superior over those based on C-CAM.2.

Claims

Patent Claims

1. Process for making a particulate (oxy)hydroxide or oxide of TM wherein TM is a combination of metals according to general formula (I)

(Ni_aCo_bMn_c)i-_dM_d (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 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 2 to 4 pm,

(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, thereby growing the solid particles of a hydroxide of TM, with a growth rate of 0.40 pm/h or less.

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 step (b) and (e), mother liquor is withdrawn from the 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 6 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. Process according to any of the preceding claims wherein step (e) is divided into two substeps.

7. Particulate (oxy)hydroxide of TM with a core-shell structure with an average particle diameter (D50) in the range of from 13 to 20 pm, determined by light scattering, and a span of the particle diameter distribution (D90-D10)/D50 from 0.20 to 0.30, wherein TM is a combination of metals according to general formula (I)

(Ni_aCo_bMn_c)i-_dM_d (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 that are radially aligned, and wherein SEM images of cross-sections said particulate (oxy)hydroxide essentially does not show any amorphous regions.

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

9. Particulate (ox)hydroxide or oxide according to any of claims 7 to 8 having an average form factor of 0.90 or more.

10. 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 the claims 7 to 9with 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 600 o 1000°C.

11. Cathode active material of the general formula Lii_+xTMi-_xO2 with x being in the range of from -0.01 to + 0.05, with an average particle diameter (D50) in the range of from 13.0 to 20.0 pm, determined by light scattering and referring to the volume-based average, and a span of the particle diameter distribution (D90-D10)/D50 from 0.20 to 0.30, wherein the particles of said cathode active material have a core-shell structure and wherein TM is a combination of metals according to general formula (I)

(Ni_aCo_bMn_c)i-_dM_d (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 the formula Lii_+xTMi-_xO2 refers to the core, and the shell comprises an oxide compound of at least one of cobalt, tungsten and boron.