PROCESS FOR PRECIPITATING A MIXED HYDROXIDE, AND CATHODE ACTIVE MATERIALS MADE FROM SUCH HYDROXIDE

Abstract

Process for precipitating a mixed hydroxide of TM wherein TM comprises Ni and at least one of Co and Mn and, optionally, Al, Mg, Zr or Ti, from an aqueous solution of salts of such transition metals or of Al or of Mg, wherein such process is carried out in a stirred vessel and comprises the step of introducing an aqueous solution of alkali metal hydroxide and an aqueous solution of transition metal salts through at least two inlets into said stirred vessel wherein the distance of the locations of introduction of salts of TM and of alkali metal hydroxide is equal or less than 6 times the hydraulic diameter of the tip of the inlet pipe of the alkali metal hydroxide.

Claims

1. A process for precipitating a mixed hydroxide of TM, wherein TM comprises Ni and at least one of Co and Mn and, optionally, Al, Mg, Zr or Ti, from an aqueous solution of salts of such transition metals or of Al or of Mg, wherein such process is carried out in a stirred vessel and comprises: introducing an aqueous solution of alkali metal hydroxide and an aqueous solution of transition metal salts through at least two inlets into the stirred vessel, wherein a distance of the locations of introducing the salts of TM and of alkali metal hydroxide is equal or less than 6 times a hydraulic diameter of a tip of the inlet of the alkali metal hydroxide.

2. The process according to claim 1, wherein the at least two inlets are designed as a coaxial mixer and the coaxial mixer comprises two coaxially arranged pipes through which an aqueous solution of alkali metal hydroxide and an aqueous solution of salts of TM are introduced into the stirred vessel.

3. The process according to claim 1, wherein the locations of introducing the aqueous solutions of metal salts and of alkali metal hydroxide are below the level of liquid in the stirred vessel.

4. The process according to claim 1, wherein the locations of introducing the aqueous solutions of metal salts and of alkali metal hydroxide are above the level of liquid in the stirred vessel.

5. The process according to any of claim 2, wherein the solution of metal salts is introduced through an inner pipe of the coaxial mixer and the solution of alkali metal hydroxide is introduced through an outer pipe.

6. The process according to claim 1, wherein the aqueous solution of alkali metal hydroxide contains comprises ammonia.

7. The process according to claim 1, wherein the stirred vessel is a continuous stirred tank reactor.

8. The process according to claim 1, wherein the at least two inlets are designed as a coaxial mixer and wherein in an interval, the coaxial mixer is flushed with water to remove transition metal (oxy)hydroxide incrustations.

9. The process according to claim 1, wherein a velocity for introducing aqueous solution of alkali metal hydroxide and aqueous solution of transition metal salts ranges from 0.01 to 10 m/s.

10. The process according to claim 1, wherein TM comprises metals according to formula (I)
Ni.sub.aM.sup.1.sub.bMn.sub.c  (I) wherein M.sup.1 is Co or a combination of Co and at least one metal chosen from Ti, Zr, Al and Mg, a ranges from 0.15 to 0.95, b ranges from zero to 0.35, c ranges from zero to 0.8, and a+b+c=1.0 and at least one of b and c is greater than zero.

11. A particulate transition metal (oxy)hydroxide according to general formula (II)
Ni.sub.aM.sup.1.sub.bMn.sub.cO.sub.x(OH).sub.y(CO.sub.3).sub.t  (II) wherein M.sup.1 is Co or a combination of Co and at least one metal chosen from Ti, Zr, Al and Mg, a ranges from 0.15 to 0.95, b ranges from zero to 0.35, c ranges from zero to 0.8, where a+b+c=1.0 and at least one of b and c is greater than zero, 0≤x<1, 1<y≤2.2, and 0≤t≤0.3, wherein at least 60 vol.-% of secondary particles consist of agglomerated primary particles that are radially oriented or deviated to a perfectly radial orientation of at most 11 degrees in an SEM analysis, and wherein the particulate transition metal has a total pore/intrusion volume ranging from 0.033 ml/g to 0.1 ml/g, determined by N.sub.2 adsorption.

12. The particulate transition metal (oxy)hydroxide according to claim 11, wherein a ranges from 0.3 to 0.9, b ranges from zero to 0.2, and c ranges from 0.05 to 0.7.

13. The particulate transition metal (oxy)hydroxide according to claim 11, wherein the particulate transitional metal (oxy)hydroxide has having a specific surface according to BET ranging from 2 m.sup.2/g to 70 m.sup.2/g.

14. The particulate transition metal (oxy)hydroxide according to claim 11, wherein the particle size distribution [(D90)−(D10)] divided by (D50) ranges from 0.5 to 2.

15. The particulate transition metal (oxy)hydroxide according to 11 wherein the nickel content at the core of the particles is higher than at the outer surface of the secondary particles.

16. (canceled)

17. A process for manufacture of an electrode active material for lithium ion batteries, wherein the process comprises: mixing a particulate transition metal (oxy)hydroxides according to claim 11 with a source of lithium and thermally treating the mixture at a temperature ranging from 600° C. to 1000° C.

18. A cathode active material according to general formula Li.sub.1+xTM.sub.1−xO.sub.2, wherein x ranges from −0.05 to 0.2 and wherein TM comprises metals according to formula (I)
Ni.sub.aM.sup.1.sub.bMn.sub.c  (I) wherein M.sup.1 is Co or a combination of Co and at least one metal chosen from Ti, Zr, Al and Mg, a ranges from 0.15 to 0.95, b ranges from zero to 0.35, c ranges from zero to 0.8, and a+b+c=1.0 and at least one of b and c is greater than zero, and wherein such cathode active material is composed from secondary particles wherein the secondary particles are agglomerates from primary particles and wherein at least 50 vol.-% of the secondary particles consist of agglomerated primary particles radially oriented or deviated to a perfectly radial orientation of at most 11 degrees in an SEM analysis.

19. The cathode active material according to claim 18, wherein the nickel content at the core of the particles is higher than at the outer surface of the secondary particles.

20. The cathode active material according to claim 18, wherein more than 50% of the primary particles exhibit an orientation deviating at most 11 degrees from the perfectly radial orientation, and 80% of primary particle exhibit an orientation deviating at most 34 degrees from a perfectly radial orientation.

21. The cathode active material according to any of claim 18, wherein the primary particle size distribution has a span [(D90)−(D10)] divided by (D50), ranging from 0.5 to 1.1.

22. The cathode active material according to claim 18, wherein the primary particles have a median primary axis ratio of more than 1.5.

Description

WORKING EXAMPLES

General Remarks:

[0141] The nickel concentrations were analyzed via energy-dispersive X-Ray spectroscopy (EDS) using cross section SEM images.

[0142] The determination of the share of and extent to which primary particles are oriented radially was performed as follows:

[0143] From the SEM images of cathode material cross sections, all identified primary particles were segmented for further analysis (outlined in FIG. 3) unless their surface could not be clearly identified for technical reasons. From the segmented primary particles, descriptive parameters for each particle were calculated, including primary particle size, primary particle axis ratio and primary particle orientation, as defined below.

[0144] The distributions of each of these quantities over all identified primary particles define the distribution parameters, like mean, median, standard deviation, percentiles, etc. of the respective quantity for the material.

[0145] The primary particle size was calculated as the diameter of a circle covering the identical area in the image as the particle.

[0146] The primary particle axis ratio was calculated as the particle length divided by its width, where the length and width are defined by the long and short side of the minimum bounding box of the respective particles, that is the smallest rectangle that encloses the primary particle.

[0147] Said determination method is an aspect of the present invention as well.

[0148] FIG. 2 is a diagram illustrating the radial direction. Brief description of FIG. 2 wherein the variables have the following meaning:

A: Secondary particle
B: Primary particle
C: Center of secondary particle
D: Center of primary particle
E: Radial direction, defined as the direction from secondary particle center to primary particle center
F: Primary particle orientation, defined as the orientation of the eigenvector with the largest eigenvalue of the covariance matrix calculated for the binary mask of the primary particle
G: Angle between primary particle orientation and ideal radial direction

[0149] For each primary particle, the minimum absolute angle (G) between the radial direction (E) and the direction of the primary particle major axis (F) is determined. Therefore, an angle of 0 means the primary particle is oriented towards ideal radial direction, and the larger the angle, the less ideally radially orientated. The distribution of angles G over the primary particles quantifies the extent to which the sample as a whole is radially oriented. For perfect radial orientation, the distribution will be located at zero, while for a perfect random orientation the angles will be distributed uniformly between 0 and 90 degrees with median and mean angles of 45 degrees.

[0150] FIG. 3A is an SEM analysis image illustrating radial direction and primary particle direction on a cross-section of a secondary particle of inventive cathode material CAM.8. FIG. 3B is an SEM analysis image of comparative cathode material C-CAM.10.

I. Manufacture of Precursors

[0151] The aqueous solution of (NH.sub.4).sub.2SO.sub.4 used in the working examples contained 26.5 g (NH.sub.4).sub.2SO.sub.4 per kg solution.

[0152] Examples 1 to 4 were carried out in a 10 L stirred vessel equipped with baffles and a cross-arm stirrer with a diameter of 0.14 m and with a coaxial mixer, see FIG. 1, in the context of said working examples also referred to as “the vessel”. The coaxial mixer was located in the vessel so that the outlet of the coaxial mixer was approximately 5 cm below the liquid level. The coaxial mixer consisted of two coaxially arranged pipes made of stainless steel. The inner and outer diameter of the inner circular pipe was 3 mm and 6 mm, respectively. The inner and outer diameter of the outer circular pipe was 8 mm and 12 mm, respectively.

I.1 Manufacture of precursor TM-OH.1:

[0153] The vessel was charged with 8 liters of the above aqueous solution of (NH.sub.4).sub.2SO.sub.4. Then, the pH of the solution was adjusted to 11.5 using an 25% by weight aqueous solution of sodium hydroxide.

[0154] The temperature of the vessel was set to 45° C. The stirrer element was activated and constantly operated at 530 rpm (average input ˜6 W/l). An aqueous solution of NiSO.sub.4, CoSO.sub.4 and MnSO.sub.4 (molar ratio 6:2:2, total metal concentration: 1.65 mol/kg), aqueous sodium hydroxide (25 wt % NaOH) and aqueous ammonia solution (25 wt % ammonia) were simultaneously introduced through the coaxial mixer into the vessel. The aqueous metal solution was introduced via the inner pipe of the coaxial mixer while the aqueous sodium hydroxide and aqueous ammonia solution were introduced via the outer pipe of the coaxial mixer. The distance between the outlets of the two coaxially arranged pipes was in the range of 5 mm.

[0155] The molar ratio between ammonia and metal was adjusted to 0.3. The sum of volume flows was set to adjust the mean residence time to 6 hours. The flow rate of the NaOH was adjusted by a pH regulation circuit to keep the pH value in the stirred vessel at a constant value of 11.5. The apparatus was operated continuously keeping the liquid level in the vessel constant. A mixed hydroxide of Ni, Co and Mn was collected via free overflow from the vessel. The resulting slurry contained about 120 g/l mixed hydroxide of Ni, Co and Mn with an average particle size (D50) of 9.6 μm, TM-OH.1. The tap density and BET surface area of the inventive precursor TM-OH.1 was 1.95 g/l and 14.1 m.sup.2/g, respectively. The total pore volume and average pore size was 0.056 ml/g and 161.6 Å. At least 70% of the secondary particle volume of the inventive precursor consisted of primary particles which were essentially radially oriented. The smaller the respective secondary particles, the lower was their nickel content. Furthermore, the outer particle surfaces contained in average 4.5% less nickel than the particles cores. On the other hand, the manganese concentration was in average 5.9% higher in the outer particle surface compared to particle cores while smaller secondary particles contained more manganese than large secondary particles (see FIGS. 4 and 5). This data was generated using EDS measurements at SEM cross section micrographs.

[0156] TM-OH.1 was excellently suited as precursor for a lithium ion battery cathode active material.

[0157] FIG. 4: Manganese content of TM-OH.1 in particle core and outer surface as function of secondary particle diameter. Manganese content was determined by EDS measurement at SEM particle cross sections

[0158] FIG. 5: Nickel content of TM-OH.1 in particle core and particle outer surface as function of secondary particle diameter. Manganese content was determined by EDS measurement at SEM particle cross sections.

I.2 Manufacture of Precursor TM-OH.2

[0159] The vessel was charged with 8 liters of the above aqueous solution of (NH.sub.4).sub.2SO.sub.4. Then, the pH of the solution was adjusted to 12.05 using an 25% by weight aqueous solution of sodium hydroxide. The temperature of the vessel was set to 45° C. The stirrer element was activated and constantly operated at 530 rpm (average input ˜6 W/l). An aqueous solution of NiSO.sub.4, CoSO.sub.4 and MnSO.sub.4 (molar ratio 6:2:2, total metal concentration: 1.65 mol/kg), aqueous sodium hydroxide (25 wt % NaOH) and aqueous ammonia solution (25 wt % ammonia) were simultaneously introduced through the coaxial mixer into the vessel. The aqueous metal solution was introduced via the inner pipe of the coaxial mixer while the aqueous sodium hydroxide and aqueous ammonia solution were introduced via the outer pipe of the coaxial mixer. The distance between the outlets of the two coaxially arranged pipes was in the range of 7 mm.

[0160] The molar ratio between ammonia and metal was adjusted to 0.3. The sum of volume flows was set to adjust the mean residence time to 6 hours. The flow rate of the NaOH was adjusted by a pH regulation circuit to keep the pH value in the vessel at a constant value of 12.05. The apparatus was operated continuously keeping the liquid level in the reaction vessel constant. A mixed hydroxide of Ni, Co and Mn was collected via free overflow from the vessel. The resulting slurry contained about 120 g/l mixed hydroxide of Ni, Co and Mn with an average particle size (D50) of 10.5 μm, TM-OH.2. Tap density and BET surface area of precursor TM-OH.2 was 2.07 g/l and 12.48 m.sup.2/g, respectively. The total pore volume and average pore size was 0.044 ml/g and 141.5 Å. At least 70% of the secondary particle volume of TM-OH.2 consisted of primary particles which were essentially radially oriented. TM-OH.2 was excellently suited as precursor for a lithium ion battery cathode active material.

I.3 Manufacture of Precursor TM-OH.3

[0161] The vessel was charged with 8 liters of the above aqueous solution of (NH.sub.4).sub.2SO.sub.4. Then, the pH of the solution was adjusted to 12.05 using an 25% by weight aqueous solution of sodium hydroxide.

[0162] The temperature of the vessel was set to 45° C. The stirrer element was activated and constantly operated at 530 rpm (average input ˜6 W/l). An aqueous solution of NiSO.sub.4, CoSO.sub.4 and MnSO.sub.4 (molar ratio 6:2:2, total metal concentration: 1.65 mol/kg), aqueous sodium hydroxide (25 wt % NaOH) and aqueous ammonia solution (25 wt % ammonia) were simultaneously introduced through the coaxial mixer into the stirred vessel. The aqueous metal solution was introduced via the inner pipe of the coaxial mixer while the aqueous sodium hydroxide and aqueous ammonia solution were introduced via the outer pipe of the coaxial mixer. The distance between the outlets of the two coaxially arranged pipes was in the range of 7 mm.

[0163] The molar ratio between ammonia and metal was adjusted to 0.35. The sum of volume flows was set to adjust the mean residence time to 6 hours. The flow rate of the NaOH was adjusted by a pH regulation circuit to keep the pH value in the stirred vessel at a constant value of 12.05. The apparatus was operated continuously keeping the liquid level in the reaction vessel constant. A mixed hydroxide of Ni, Co and Mn was collected via free overflow from the vessel. The resulting slurry contained about 120 g/l mixed hydroxide of Ni, Co and Mn with an average particle size (D50) of 9.8 μm, TM-OH.3. The tap density and BET surface area of TM-OH.3 was 2.0 g/l and 11.3 m.sup.2/g, respectively. The total pore volume and average pore size of TM-OH.3 was 0.037 ml/g and 132.0 Å. At least 70% of the secondary particle volume of TM-OH.3 consisted of primary particles which were essentially radially oriented. TM-OH.3 was excellently suited as precursor for a lithium ion battery cathode active material.

I.4 Manufacture of Precursor TM-OH.4

[0164] The vessel was charged with 8 liters of the above aqueous solution of (NH.sub.4).sub.2SO.sub.4. Then, the pH of the solution was adjusted to 11.5 using an 25% by weight aqueous solution of sodium hydroxide.

[0165] The temperature of the vessel was set to 55° C. The stirrer element was activated and constantly operated at 530 rpm (average input ˜6 W/l). An aqueous solution of NiSO.sub.4, CoSO.sub.4 and MnSO.sub.4 (molar ratio 87:5:8, total metal concentration: 1.65 mol/kg), aqueous sodium hydroxide (25 wt % NaOH) and aqueous ammonia solution (25 wt % ammonia) were simultaneously introduced through the coaxial mixer into the stirred vessel. The aqueous metal solution was introduced via the inner pipe of the coaxial mixer while the aqueous sodium hydroxide and aqueous ammonia solution were introduced via the outer pipe of the coaxial mixer. The distance between the outlets of the two coaxially arranged pipes was in the range of 5 mm.

[0166] The molar ratio between ammonia and metal was adjusted to 0.2. The sum of volume flows was set to adjust the mean residence time to 6 hours. The flow rate of the NaOH was adjusted by a pH regulation circuit to keep the pH value in the vessel at a constant value of 11.5. The apparatus was operated continuously keeping the liquid level in the vessel constant. A mixed hydroxide of Ni, Co and Mn was collected via free overflow from the vessel. The resulting slurry contained about 120 g/l mixed hydroxide of Ni, Co and Mn with an average particle size (D50) of 12.3 μm, TM-OH.4. The tap density and BET surface area of TM-OH.4 was 1.91 g/l and 17.94 m.sup.2/g, respectively. The total pore volume and average pore size of TM-OH.4 was 0.045 ml/g and 106.3 Å. At least 70% of the secondary particle volume of TM-OH.4 consisted of primary particles which were essentially radially oriented.

[0167] Furthermore, the outer particle surfaces of the secondary particles contained in average 3.7% less nickel than the particles cores. On the other hand, the manganese concentration was in average 4.9% higher in particle surfaces compared to particle cores while small secondary particles contained more manganese than large secondary particles (see FIGS. 6 and 7). This data was generated using EDS measurements at SEM cross section micrographs.

[0168] TM-OH.4 was excellently suited as precursor for a lithium ion battery cathode active material.

I.5 Manufacture of Precursor TM-OH.5

[0169] A 50 L stirred vessel equipped with baffles and a cross-arm stirrer with a diameter of 0.21 m and a coaxial mixer, see FIG. 1, was charged with 40 liters of the above aqueous solution of (NH.sub.4).sub.2SO.sub.4. Then, the pH of the solution was adjusted to 11.6 using an 25% by weight aqueous solution of sodium hydroxide. The coaxial mixer was located in the vessel so that the outlet of the coaxial mixer was approximately 10 cm below the liquid level. The coaxial mixer consisted of two coaxially arranged pipes made of stainless steel. The inner and outer diameter of the inner circular pipe was 1 mm and 4 mm, respectively. The inner and outer diameter of the outer circular pipe was 2 mm and 6 mm, respectively.

[0170] The temperature of the vessel was set to 55° C. The stirrer element was activated and constantly operated at 420 rpm (average input ˜12.6 W/l). An aqueous solution of NiSO.sub.4, CoSO.sub.4 and MnSO.sub.4 (molar ratio 83:12:5, total metal concentration: 1.65 mol/kg), aqueous sodium hydroxide (25 wt % NaOH) and aqueous ammonia solution (25 wt % ammonia) were simultaneously introduced through the coaxial mixer into the vessel. The aqueous metal solution was introduced via the inner pipe of the coaxial mixer while the aqueous sodium hydroxide and aqueous ammonia solution were introduced via the outer pipe of the coaxial mixer. The distance between the outlets of the two coaxially arranged pipes was in the range of 15 mm.

[0171] The molar ratio between ammonia and metal was adjusted to 0.265. The sum of volume flows was set to adjust the mean residence time to 5 hours. The flow rate of the NaOH was adjusted by a pH regulation circuit to keep the pH value in the vessel at a constant value of 11.58. The apparatus was operated continuously keeping the liquid level in the vessel constant. A mixed hydroxide of Ni, Co and Mn was collected via free overflow from the vessel. The resulting product slurry contained about 120 g/l mixed hydroxide of Ni, Co and Mn with an average particle size (D50) of 10.5 μm, TM-OH.5. The tap density and BET surface area of TM-OH.5 were 1.95 g/l and 23.1 m.sup.2/g, respectively. The total pore volume and average pore size of TM-OH.5 were 0.074 ml/g and 127.7 Å. At least 70% of the secondary particle volume TM-OH.5 consisted of primary particles which were essentially radially oriented. TM-OH.5 was excellently suited as precursor for a lithium ion battery cathode active material.

I.6 Manufacture of Precursor TM-OH.6

[0172] A 50 L stirred vessel equipped with baffles and a cross-arm stirrer with a diameter of 0.21 m and a coaxial mixer, see FIG. 1, was charged with 40 liters of the above aqueous solution of (NH.sub.4).sub.2SO.sub.4. Then, the pH of the solution was adjusted to 11.9 using an 25% by weight aqueous solution of sodium hydroxide. The coaxial mixer was located in the vessel so that the outlet of the coaxial mixer was approximately 10 cm below the liquid level. The coaxial mixer consisted of two coaxially arranged pipes made of stainless steel. The inner and outer diameter of the inner circular pipe was 1 mm and 4 mm, respectively. The inner and outer diameter of the outer circular pipe was 2 mm and 6 mm, respectively.

[0173] The temperature of the vessel was set to 55° C. The stirrer element was activated and constantly operated at 420 rpm (average input ˜12.6 W/l). An aqueous solution of NiSO.sub.4, CoSO.sub.4 and MnSO.sub.4 (molar ratio 83:12:5, total metal concentration: 1.65 mol/kg), aqueous sodium hydroxide (25 wt % NaOH) and aqueous ammonia solution (25 wt % ammonia) were simultaneously introduced through the coaxial mixer into the vessel. The aqueous metal solution was introduced via the inner pipe of the coaxial mixer while the aqueous sodium hydroxide and aqueous ammonia solution were introduced via the outer pipe of the coaxial mixer. The distance between the outlets of the two coaxially arranged pipes was in the range of 30 mm.

[0174] The molar ratio between ammonia and metal was adjusted to 0.265. The sum of volume flows was set to adjust the mean residence time to 5 hours. The flow rate of the NaOH was adjusted by a pH regulation circuit to keep the pH value in the vessel at a constant value of 11.9. The apparatus was operated continuously keeping the liquid level in the reaction vessel constant. A mixed hydroxide of Ni, Co and Mn was collected via free overflow from the vessel. The resulting slurry contained about 120 g/l mixed hydroxide of Ni, Co and Mn with an average particle size (D50) of 12.3 μm, TM-OH.6. The tap density and BET surface area of TM-OH.6 were 1.93 g/l and 20.91 m.sup.2/g, respectively. The total pore volume and average pore size of TM-OH.6 were 0.066 ml/g and 126.2 Å. At least 70% of the secondary particle volume of TM-OH.6 consisted of primary particles which were essentially radially oriented. TM-OH.6 was excellently suited as precursor for a lithium ion battery cathode active material.

I.7 Manufacture of Precursor TM-OH.7

[0175] A 50 L stirred vessel equipped with baffles and a cross-arm stirrer with a diameter of 0.21 m and a coaxial mixer, see FIG. 1, was charged with 40 liters of the above aqueous solution of (NH.sub.4).sub.2SO.sub.4. Then, the pH of the solution was adjusted to 11.9 using an 25% by weight aqueous solution of sodium hydroxide. The coaxial mixer was located in the vessel so that the outlet of the coaxial mixer was approximately 10 cm below the liquid level. The coaxial mixer consisted of two coaxially arranged pipes made from FEP. The inner and outer diameter of the inner circular pipe was 1.5 mm and 3.2 mm, respectively. The inner and outer diameter of the outer circular pipe was 4 mm and 6 mm, respectively.

[0176] The temperature of the vessel was set to 55° C. The stirrer element was activated and constantly operated at 420 rpm (average input 12.6 W/l). An aqueous solution of NiSO.sub.4, CoSO.sub.4 and MnSO.sub.4 (molar ratio 83:12:5, total transition metal concentration: 1.65 mol/kg), aqueous sodium hydroxide (25 wt % NaOH) and aqueous ammonia solution (25 wt % ammonia) were simultaneously introduced through the coaxial mixer into the vessel. The aqueous metal solution was introduced via the inner pipe of the coaxial mixer while the aqueous sodium hydroxide and aqueous ammonia solution were introduced via the outer pipe of the coaxial mixer. The distance between the outlets of the two coaxially arranged pipes was in the range of 30 mm.

[0177] The molar ratio between ammonia and metal was adjusted to 0.265. The sum of volume flows was set to adjust the mean residence time to 5 hours. The flow rate of the NaOH was adjusted by a pH regulation circuit to keep the pH value in the vessel at a constant value of 11.9. The apparatus was operated continuously keeping the liquid level in the reaction vessel constant. A mixed hydroxide of Ni, Co and Mn was collected via free overflow from the vessel. The resulting slurry contained about 120 g/l mixed hydroxide of Ni, Co and Mn with an average particle size (D50) of 12.3 μm, TM-OH.7. The tap density and BET surface area of TM-OH.7 were 1.93 g/l and 21.3 m.sup.2/g, respectively. The total pore volume and average pore size of TM-OH.7 were 0.066 ml/g and 126.2 Å. At least 70% of the secondary particle volume of TM-OH.7 consisted of primary particles which were essentially radially oriented. TM-OH.7 was excellently suited as precursor for a lithium ion battery cathode active material.

I.8 Manufacture of Precursor TM-OH.8

[0178] A 50 L stirred vessel equipped with baffles and a cross-arm stirrer with a diameter of 0.21 m and a coaxial mixer, see FIG. 1, was charged with 40 liters of the above aqueous solution of (NH.sub.4).sub.2SO.sub.4. Then, the pH of the solution was adjusted to 11.88 using an 25% by weight aqueous solution of sodium hydroxide. The coaxial mixer was located in the vessel so that the outlet of the coaxial mixer was approximately 10 cm below the liquid level. The coaxial mixer consisted of two coaxially arranged pipes made of FEP. The inner and outer diameter of the inner circular pipe was 1.5 mm and 3.2 mm, respectively. The inner and outer diameter of the outer circular pipe was 4 mm and 6 mm, respectively.

[0179] The temperature of the vessel was set to 55° C. The stirrer element was activated and constantly operated at 420 rpm (average input ˜12.6 W/l). An aqueous solution of NiSO.sub.4, CoSO.sub.4 and MnSO.sub.4 (molar ratio 83:12:5, total metal concentration: 1.65 mol/kg), aqueous sodium hydroxide (25 wt % NaOH) and aqueous ammonia solution (25 wt % ammonia) were simultaneously introduced through the coaxial mixer into the vessel. The aqueous metal solution was introduced via the inner pipe of the coaxial mixer while the aqueous sodium hydroxide and aqueous ammonia solution were introduced via the outer pipe of the coaxial mixer. The distance between the outlets of the two coaxially arranged pipes was in the range of 30 mm.

[0180] The molar ratio between ammonia and metal was adjusted to 0.265. The sum of volume flows was set to adjust the mean residence time to 5 hours. The flow rate of the NaOH was adjusted by a pH regulation circuit to keep the pH value in the vessel at a constant value of 11.9. The apparatus was operated continuously keeping the liquid level in the reaction vessel constant. A mixed hydroxide of Ni, Co and Mn was collected via free overflow from the vessel. The resulting slurry contained about 120 g/l mixed hydroxide of Ni, Co and Mn with an average particle size (D50) of 12.0 μm, TM-OH.8. The tap density and BET surface area of TM-OH.8 were 1.92 g/l and 20.58 m.sup.2/g, respectively. At least 70% of the secondary particle volume of TM-OH.8 consisted of primary particles which were essentially radially oriented. TM-OH.8 was excellently suited as precursor for a lithium ion battery cathode active material.

I.9 Comparative Example—Manufacture of a Comparative Precursor C-TM-OH.9

[0181] A 50 L stirred vessel equipped with baffles and a cross-arm stirrer with a diameter of 0.21 m and a coaxial mixer, see FIG. 1, was charged with 40 liters of the above aqueous solution of (NH.sub.4).sub.2SO.sub.4. Then, the pH value of the solution was adjusted to 11.4 using an 25% by weight aqueous solution of sodium hydroxide. In this experiment, feeds were not added through a coaxial mixer. Instead, the transition metal feed was dosed via a dipped pipe with inner diameter of 4 mm close to stirrer element while NaOH and ammonia were dosed via a separate dipped pipe with inner diameter of 4 mm close to the stirrer element. The outlets of both pipes had a distance larger than 10 times of the inner hydraulic diameter of alkali dosing pipe.

[0182] The temperature of the vessel was set to 55° C. The stirrer element was activated and constantly operated at 420 rpm (average input 12.6 W/l). An aqueous solution of NiSO.sub.4, CoSO.sub.4 and MnSO.sub.4 (molar ratio 83:12:5, total metal concentration: 1.65 mol/kg), aqueous sodium hydroxide (25 wt % NaOH) and aqueous ammonia solution (25 wt % ammonia) were introduced simultaneously.

[0183] The molar ratio between ammonia and transition metal was adjusted to 0.115. The sum of volume flows was set to adjust the mean residence time to 5 hours. The flow rate of the NaOH was adjusted by a pH regulation circuit to keep the pH value in the vessel at a constant value of 11.4. The apparatus was operated continuously keeping the liquid level in the reaction vessel constant. A mixed hydroxide of Ni, Co and Mn was collected via free overflow from the vessel. The resulting slurry contained about 120 g/l mixed hydroxide of Ni, Co and Mn with an average particle size (D50) of 10.2 μm, C-TM-OH.9. C-TM-OH.9 was used as precursor for a comparative lithium ion battery cathode active material.

I.10 Comparative Example—Manufacture of a Comparative Precursor C-TM-OH.10

[0184] A 50 L stirred vessel equipped with baffles and a cross-arm stirrer with a diameter of 0.21 m and a coaxial mixer, see FIG. 1, was charged with 40 liters of the above aqueous solution of (NH.sub.4).sub.2SO.sub.4. Then, the pH of the solution was adjusted to 12.34 using an 25% by weight aqueous solution of sodium hydroxide. In this experiment, feeds were not dosed by coaxial mixer. Instead, the transition metal feed was dosed via a dipped pipe with inner diameter of 4 mm close to stirrer element while NaOH and ammonia were dosed via a separate dipped pipe with inner diameter of 4 mm close to stirrer element. The outlets of both pipes had a distance larger than 10 times of the inner hydraulic diameter of alkali dosing pipe.

[0185] The temperature of the vessel was set to 55° C. The stirrer element was activated and constantly operated at 420 rpm (average input ˜12.6 W/l). An aqueous metal solution containing NiSO.sub.4, CoSO.sub.4 and MnSO.sub.4 (molar ratio 87:5:8, total metal concentration: 1.65 mol/kg), aqueous sodium hydroxide (25 wt % NaOH) and aqueous ammonia solution (25 wt % ammonia) were introduced simultaneously.

[0186] The molar ratio between ammonia and metal was adjusted to 0.4. The sum of volume flows was set to adjust the mean residence time to 5 hours. The flow rate of the NaOH was adjusted by a pH regulation circuit to keep the pH value in the vessel at a constant value of 12.34. The apparatus was operated continuously keeping the liquid level in the reaction vessel constant. A mixed hydroxide of Ni, Co and Mn was collected via free overflow from the vessel. The resulting slurry contained about 120 g/l mixed hydroxide of Ni, Co and Mn with an average particle size (D50) of 13.0 μm, C-TM-OH.10. C-TM-OH.10 was used as precursor for a comparative lithium ion battery cathode active material.

II. Manufacture of Inventive Cathode Active Materials

[0187] II.1 Manufacture of Inventive Cathode Material CAM.1 Made from TM-OH.1

[0188] The precursor TM-OH.1 was mixed with LiOH monohydrate and crystalline Al.sub.2O.sub.3 in a concentration of 0.3 mole-% Al relative to Ni+Co+Mn+Al and a Li/(Ni+Co+Mn+Al) molar ratio of 1.02. The resultant mixture was heated to 820° C. and kept for 8 h in a forced flow of oxygen. After natural cooling the obtained calcined powder was de-agglomerated and sieved through a 32 μm vibrational screen. Cathode active material CAM.1 was obtained.

[0189] The 0.1C first discharge of CAM.1, measured in half-cell, amounted 187.0 mAh/g. The capacity after 100 cycles in half-cell amounted 99.8%, respectively.

[0190] 11.2 Manufacture of inventive cathode material CAM.4 made from TM-OH.4 The precursor TM-OH.4 was mixed with LiOH monohydrate and crystalline Al.sub.2O.sub.3 in a concentration of 0.3 mole-% Al relative to Ni+Co+Mn+Al and a Li/(Ni+Co+Mn+Al) molar ratio of 1.02. The resultant mixture was heated to 820° C. and kept for 5 h in a forced flow of oxygen. After natural cooling the obtained calcined powder was de-agglomerated and sieved through a 32 μm vibrational screen. Cathode active material CAM.4 was obtained.

[0191] The 0.1C first discharge of CAM.4, measured in half-cell, amounted 186.0 mAh/g. The capacity after 100 cycles in half-cell amounted 98.5%, respectively.

II.3 Manufacture of Inventive Cathode Material CAM.5 Made from TM-OH.5

[0192] The precursor TM-OH.5 was mixed with LiOH monohydrate in a Li/(Ni+Co+Mn) molar ratio of 1.02. The resultant mixture was heated to 760° C. and kept for 6 h in a forced flow of oxygen. After natural cooling the obtained calcined powder was deagglomerated and sieved through a 32 μm vibrational screen. Cathode active material CAM.5 was obtained.

[0193] The median primary particle diameter is 0.24 μm with a span of 0.92 and a median axis ratio of 1.88.

[0194] The orientation of 20% of the primary particles of CAM.5 deviated 2.8 degrees or less from the ideal radial orientation, 50% deviated 10.5 degrees or less, and even 80% deviated or less. An exemplary micrograph of SEM cross section of inventive CAM.5 is shown in FIG. 3B.

[0195] The 0.1C first discharge of CAM.5, measured in half-cell, amounted to 205.8 mAh/g. The capacity after 50 and 100 1C cycles in full-cell amounted to 97.9% and 90.6%, respectively.

II.4 Manufacture of Inventive Cathode Material CAM.8 Made from TM-OH.8

[0196] The precursor TM-OH.8 was mixed with LiOH monohydrate as well as with TiO.sub.2 and Zr(OH).sub.4 with concentrations of 0.17 mole-% Zr and 0.17 mole % Ti relative to Ni+Co+Mn+Zr+Ti and a Li/(Ni+Co+Mn+Zr+Ti) molar ratio of 1.05. The mixture was heated to 780° C. and kept for 6 h in a forced flow of oxygen. After natural cooling the obtained calcined powder was deagglomerated and sieved through a 32 μm vibrational screen. Cathode active material CAM.8 was obtained.

[0197] The median primary particle diameter was 0.37 μm with a span of 1.10 and a median axis ratio of 1.56. The orientation of 20% of primary particles deviated 4.3 degrees or less from the ideal radial orientation, 50% deviated 10.7 degrees or less, and even 80% deviated 31.0 degrees or less.

[0198] The 0.1C first discharge of CAM.8, measured in half-cell, amounted 204.7 mAh/g. The capacity after 50 and 100 1C cycles in full-cell amounted 96.3% and 94.1%, respectively.

II.5 Comparative Example—Manufacture of Cathode Material C-CAM.10 Made from C-TMOH.10

[0199] The precursor TM-OH.10 was mixed with LiOH monohydrate as well as with TiO.sub.2 and a Zr(OH).sub.4 with concentrations of 0.17 mole-% Zr and 0.17 mole % Ti relative to Ni+Co+Mn+Zr+Ti and a Li/(Ni+Co+Mn+Zr+Ti) molar ratio of 1.04. The resultant mixture was heated to 760° C. and kept for 5 h in a forced flow of oxygen. After natural cooling the obtained calcined powder was deagglomerated and sieved through a 32 μm vibrational screen. Cathode active material C-CAM.10 was obtained.

[0200] The median primary particle diameter was 0.27 μm with a span of 1.27 and a median axis ratio of 1.44. An exemplified micrograph of SEM cross section of comparative cathode active material C-CAM.10 is shown in FIG. 3A.

[0201] The orientation of 20% of primary particles deviated 9.0 degrees or less from the ideal radial orientation, 50% deviated 20.3 degrees or less, and 80% deviate 45.0 degrees or less. The 0.1C first discharge of C-CAM.10, measured in half-cell, amounted to 203.7 mAh/g. The capacity after 50 and 100 1C cycles in full-cell amounted to 94.2% and 86.5%, respectively.

III. Electrochemical Tests

[0202] Percentages are—unless specified otherwise—weight percent. In case of cathodes, the percentages refer to the entire cathode minus the current collector.

III.1 Cathode Manufacture

[0203] Electrode manufacture: Electrodes contained 93% of the respective cathode active material, 1.5% carbon black (Super C65), 2.5% graphite (SFG6 L) and 3% binder (polyvinylidene fluoride, Solef 5130). Slurries were mixed in N-methyl-2-pyrrolidone and cast onto aluminum foil by doctor blade. After drying of the electrodes 6 h at 105° C. in vacuo, circular electrodes were punched, weighed and dried at 120° C. under vacuum overnight before entering in an Ar filled glove box.

III.2 Electrolyte

[0204] Electrolyte 1: 1 M LiPF.sub.6 in ethylene carbonate (EC): dimethyl carbonate (DMC), 1:1 by weight, was used as the electrolyte.

[0205] Electrolyte 2: 1 M LiPF.sub.6 in EC: ethyl methyl carbonate (EMC), 1:1 by weight, containing 2 wt-% vinylene carbonate

III.3 Anode

[0206] A 0.58 mm thick Li foil

III.3 Manufacture of Half-Cell Type Coin Cells

[0207] Coin-type electrochemical cells were assembled in an argon-filled glovebox. The positive 14 mm diameter (loading 11.0.Math.0.4 mg cm.sup.−2) electrode was separated from the anode by a glass fiber separator (Whatman GF/D). An amount of 100 μl of electrolyte 1 was used for the half cells.

[0208] A Maccor 4000 system was used for testing. The cells were galvanostaticylly cycled between 3 and 4.3V vs Li and then potentiostatically at 4.3V for 30 min or until the current was below the 0.01C current. The cells were placed in the Binder climate chambers at a defined temperature of 25° C. The cell were cycled for 129 cycles, first at the 0.1C/0.1C (charge/discharge, hereafter) rate for 2 cycles for the capacity determination; then at the 0.1C/0.1C rate for 5 cycles for conditioning; then at the 0.5C/0.1C, 0.5C/0.2C, 0.5C/0.5C, 0.5C/1C, 0.5C/2C, 0.5C/3C, rate for 6 cycles for the discharge rate capability determination; then at the 0.5C/0.1C rate for 2 cycles for the capacity determination; then at the 0.5C/0.1C rate for 50 cycles for the cycling stability determination; then at the 0.5C/0.1C rate for 2 cycles for the capacity determination; then at the 0.5C/0.1C rate for 50 cycles for the cycling stability determination; then at the 0.5C/0.1C rate for 2 cycles for the capacity determination and finally at the 0.5C/0.1C rate for 10 cycles for the cycling stability determination.

III.4 Manufacture of Full-Cell Type Coin Cells

[0209] Full-Cell Electrochemical Measurements: Coin-type electrochemical cells were assembled in an argon-filled glovebox. The positive 17.5 mm diameter (loading: 11.3.1.1 mg cm.sup.−2) electrode was separated from the 18.5 mm graphite anode by a glass fiber separator (Whatman GF/D). An amount of 300 μl of was electrolyte 2. Cells were galvanostatically cycled be-tween 2.7 and 4.20 V at a the 1C rate and 45° C. with a potentiostatic charge step at 4.2 V for 1 h or until the current drops below 0.02C using a Maccor 4000 battery cycler.

[0210] During the resistance measurement (conducted every 25 cycles at 25° C.), the cell was charged in the same manner as for cycling. Then, the cell was discharged for 30 min at 1 C to reach 50% state of charge. To equilibrate the cell, a 30 s open circuit step followed. Finally, a 2.5 C discharge current was applied for 30 s to measure the resistance. At the end of the current pulse, the cell was again equilibrated for 30 s in open circuit and further discharged at 1 C to 2.7 V vs. graphite.

[0211] To calculate the resistance, the voltage before applying the 2.5 C pulse current, VOs, and after 10 s of 2.5 C pulse current, V10 s, as well as the 2.5 C current value, (I in A), were taken. The resistance was calculated according to Eq. 1 (S: electrode area, V: voltage, I: 2.5C pulse current).

R=(V0s−V10s)/I*S  (Eq. 1)