阅读说明：本技术 沉淀混合氢氧化物的方法和由该氢氧化物制备的阴极活性材料 (Method for precipitating mixed hydroxide and cathode active material prepared from the same ) 是由 T·拜尔令 S·施勒德勒 J·西奥斯 D·菲斯特尔 B·卡洛 C·埃尔克 B·龙 C· 于 2020-04-02 设计创作，主要内容包括：由过渡金属或Al或Mg的盐的水溶液沉淀TM的混合氢氧化物的方法,其中TM包含Co和Mn中的至少一种以及Ni和任选的Al、Mg、Zr或Ti,其中该方法在搅拌容器中进行,并且包括通过至少两个入口将碱金属氢氧化物水溶液和过渡金属盐水溶液引入所述搅拌容器中的步骤,其中TM的盐和碱金属氢氧化物的引入位置的距离等于或小于碱金属氢氧化物入口管尖端的水力直径的6倍。(A method for precipitating TM mixed hydroxides from an aqueous solution of a salt of a transition metal or Al or Mg, wherein TM comprises at least one of Co and Mn and Ni and optionally Al, Mg, Zr or Ti, wherein the method is performed in a stirred vessel and comprises the step of introducing an aqueous solution of an alkali metal hydroxide and an aqueous solution of a transition metal salt into said stirred vessel through at least two inlets, wherein the distance of the TM salt and the alkali metal hydroxide introduction positions is equal to or less than 6 times the hydraulic diameter of the alkali metal hydroxide inlet tube tip.)

1. A method of precipitating TM mixed hydroxides from an aqueous solution of a salt of a transition metal or Al or Mg, wherein TM comprises at least one of Co and Mn and Ni and optionally Al, Mg, Zr or Ti, wherein the method is performed in a stirred vessel and comprises the step of introducing an aqueous solution of an alkali metal hydroxide and an aqueous solution of a transition metal salt into the stirred vessel through at least two inlets, wherein the distance of the introduction positions of the TM salt and the alkali metal hydroxide is equal to or less than 6 times the hydraulic diameter of the inlet tip of the alkali metal hydroxide.

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

3. The process according to claim 1 or 2, wherein the aqueous solution of the metal salt and the alkali metal hydroxide is introduced at a position lower than the liquid level in the stirred vessel.

4. The process according to claim 1 or 2, wherein the aqueous solution of the metal salt and the alkali metal hydroxide is introduced at a position higher than the liquid level in the stirred vessel.

5. The process according to any one of claims 2 to 4, wherein the metal salt solution is introduced through the inner tube of the coaxial mixer and the solution of alkali metal hydroxide is introduced through the outer tube.

6. The method of any preceding claim, wherein the aqueous alkali metal hydroxide solution comprises ammonia.

7. The process of any one of the preceding claims, wherein the stirred vessel is a continuous stirred tank reactor.

8. The process according to any of the preceding claims, wherein at least two inlets are designed as coaxial mixers and wherein at certain intervals the coaxial mixers are flushed with water to physically remove transition metal hydroxide or oxyhydroxide encrustations.

9. The process according to any one of the preceding claims, wherein the rate of introduction of the aqueous alkali metal hydroxide solution and of the aqueous transition metal salt solution is from 0.01 to 10 m/s.

10. The method of any one of the preceding claims, wherein TM comprises a metal according to formula (I):

Ni_aM¹ _bMn_c (I)

wherein the variables are each defined as follows:

M¹is Co or a combination of Co and at least one metal selected from Ti, Zr, Al and Mg,

a is 0.15 to 0.95,

b is 0 to 0.35 of a,

c is 0 to 0.8, and

a + b + c is 1.0, and at least one of b and c is greater than 0.

11. A particulate transition metal hydroxide or oxyhydroxide according to the general formula (II):

Ni_aM¹ _bMn_cO_x(OH)_y(CO₃)_t (II)

wherein the variables are each defined as follows:

M¹is Co or a combination of Co and at least one metal selected from Ti, Zr, Al and Mg,

a is 0.15 to 0.95,

b is 0 to 0.35 of a,

c is 0 to 0.8 of a compound,

wherein a + b + c is 1.0 and at least one of b and c is greater than 0,

x is more than or equal to 0 and less than 1, y is more than 1 and less than or equal to 2.2, t is more than or equal to 0 and less than or equal to 0.3,

wherein at least 60% by volume of the secondary particles consist of agglomerated primary particles which are substantially radially oriented, and

wherein the particulate transition metal has a transition metal group having a transition metal group of N₂Adsorption was determined to be 0.033 to 0.1ml/g total pore/intrusion volume.

12. The particulate transition metal hydroxide or oxyhydroxide according to claim 11,

wherein:

a is 0.3 to 0.9,

b is 0 to 0.2 of a compound,

c is 0.05-0.7.

13. The particulate transition metal hydroxide or oxyhydroxide according to claim 11 or 12 having a BET of 2 to 70m²Specific surface area in g.

14. The particulate transition metal hydroxide or oxyhydroxide according to any one of claims 11 to 13, wherein the particle size distribution of [ (D90) - (D10) ] divided by (D50) is from 0.5 to 2.

15. The particulate transition metal hydroxide or oxyhydroxide according to any one of claims 11 to 14, wherein the nickel content at the core of the particle is higher than the nickel content at the outer surface of the secondary particle.

16. Use of the particulate transition metal hydroxide or oxyhydroxide according to any one of claims 11 to 15 in the preparation of a lithium ion battery cathode active material.

17. A method of preparing a lithium ion battery electrode active material, wherein the method comprises the steps of mixing the particulate transition metal hydroxide or oxyhydroxide according to any one of claims 11-15 with a lithium source and heat treating the mixture at a temperature of 600-.

18. According to the formula Li_1+xTM_1-xO₂Wherein x is-0.05 to 0.2, and wherein TM comprises a metal according to formula (I):

Ni_aM¹ _bMn_c (I)

wherein the variables are each defined as follows:

M¹is Co or a combination of Co and at least one metal selected from Ti, Zr, Al and Mg,

a is 0.15 to 0.95,

b is 0 to 0.35 of a,

c is 0 to 0.8, and

a + b + c is 1.0, and at least one of b and c is greater than 0,

and wherein the cathode active material comprises secondary particles, wherein the secondary particles are agglomerates formed from primary particles, and wherein at least 50 volume percent of the secondary particles consist of agglomerated primary particles that are substantially radially oriented.

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

20. The cathode active material according to claim 18 or 19, wherein greater than 50% of the primary particles exhibit an orientation that deviates at most 11 degrees from a perfect radial orientation and 80% of the primary particles exhibit an orientation that deviates at most 34 degrees from a perfect radial orientation.

21. The cathode active material according to any one of claims 18-20, wherein the primary particle size distribution has a span [ (D90) - (D10) ] of 0.5-1.1 divided by (D50).

22. The cathode active material according to any one of claims 18 to 21, wherein the median major axis ratio of the primary particles is greater than 1.5.

Brief description of the drawings. FIG. 1:

a: stirring container

B: stirrer

C: inner pipe wall of coaxial mixer

D: outer tube wall of coaxial mixer

E: baffle plate

F: engine of stirrer

Working examples are as follows:

general remarks:

the nickel concentration was analyzed by energy dispersive X-ray spectroscopy (EDS) using cross-sectional SEM images.

The proportion and degree of radial orientation of the primary particles are determined as follows:

from the SEM image of the cathode material cross-section, 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 are calculated, including primary particle size, primary particle axial ratio, and primary particle orientation, as defined below.

The distribution of each of these quantities over all the identified primary particles defines a distribution parameter for the respective quantity of material, such as the mean, median, standard deviation, percentile, etc.

The primary particle size is calculated as the diameter of a circle covering the same area of the image as the particle.

The primary particle axial ratio is calculated as the particle length divided by its width, where the length and width are defined by the long and short sides of the smallest bounding box (i.e., the smallest rectangle that encloses the primary particle) of the respective particle.

The assay method is also an aspect of the present invention.

Fig. 2 is a view showing a radial direction. Brief description of fig. 2, wherein the variables have the following meanings:

a: secondary particles

B: primary particles

C: center of secondary particle

D: center of primary particle

E: radial direction, defined as the direction from the center of the secondary particle to the center of the primary particle

F: primary particle orientation, defined as the orientation of the eigenvector with the largest eigenvalue of the covariance matrix calculated for the binary template of the primary particles

G: angle between primary particle orientation and ideal radial direction

For each primary particle, the smallest absolute angle (G) between the radial direction (E) and the direction of the major axis (F) of the primary particle is determined. Thus, an angle of 0 means that the primary particles are oriented towards the ideal radial orientation, and the larger the angle, the less ideal the radial orientation. The distribution of the angle G over the primary particles quantifies the degree to which the sample is radially oriented as a whole. For perfect radial orientation, the distribution will lie at 0, while for perfect random orientation, the angles will be evenly distributed between 0 and 90 degrees, with the median and average angles being 45 degrees.

Fig. 3A is an SEM analysis image showing the radial and primary particle directions on a cross section of the secondary particles of the cathode material cam.8 of the present invention. FIG. 3B is an SEM analysis image of comparative cathode material C-CAM.10.

I. Preparation of the precursor

(NH) used in working examples₄)₂SO₄The aqueous solution contained 26.5g (NH)₄)₂SO₄Per kg of solution.

Examples 1 to 4 were carried out in a 10L stirred vessel equipped with baffles and a cross-arm stirrer having a diameter of 0.14m and with a coaxial mixer, see fig. 1, also referred to as "vessel" in the context of the working example. The in-line mixer was located in the vessel such that the outlet of the in-line mixer was about 5cm below the liquid level. The coaxial mixer consists of two coaxially arranged stainless steel tubes. The inner diameter and the outer diameter of the inner circular tube are respectively 3mm and 6 mm. The inner diameter and the outer diameter of the outer circular tube are respectively 8mm and 12 mm.

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

to the vessel was added 8 liters of (NH) as described above₄)₂SO₄An aqueous solution. The pH of the solution was then adjusted to 11.5 with 25 wt% aqueous sodium hydroxide.

The temperature of the vessel was set to 45 ℃. The stirrer elements were started and operated constantly at 530rpm (average input 6W/l). Mixing NiSO₄、CoSO₄And MnSO₄Was introduced into a vessel simultaneously with an aqueous solution of sodium hydroxide (25% by weight NaOH) and an aqueous ammonia solution (25% by weight ammonia) in a molar ratio of 6:2:2, total metal concentration of 1.65mol/kg, through a coaxial mixer. The aqueous metal solution was introduced through the inner tube of the coaxial mixer, and the aqueous sodium hydroxide solution and the aqueous ammonia solution were introduced through the outer tube of the coaxial mixer. The distance between the outlets of the two coaxially arranged tubes is in the range of 5 mm.

The molar ratio of ammonia to metal was adjusted to 0.3. The sum of the volume flows was set to adjust the mean residence time to 6 hours. The flow rate of NaOH was adjusted through the pH adjustment loop to maintain the pH in the stirred vessel at a constant value of 11.5. The apparatus was operated continuously, keeping the liquid level in the vessel constant. The mixed hydroxides of Ni, Co and Mn were collected by free overflow from the vessel. The resulting slurry contained about 120g/l of mixed hydroxide of Ni, Co and Mn with an average particle size (D50) of 9.6 μm, TM-OH.1. The bulk density and BET surface area of the precursor TM-OH.1 of the present invention were 1.95g/l and 14.1m, respectively²(ii) in terms of/g. The total pore volume and average pore size being 0.056ml/g andat least 70% by volume of the secondary particles of the precursor of the invention consist of primary particles which are substantially radially oriented. The smaller the individual secondary particles, the lower their nickel content. In addition, the outer surface of the particles contained an average of 4.5% less nickel than the core of the particles. On the other hand, the outer surface of the particle is compared to the core of the particleThe manganese concentration in (a) is on average 5.9% higher, while the smaller secondary particles contain more manganese than the larger secondary particles (see fig. 4 and 5). The data was generated on SEM cross-sectional micrographs using EDS measurements.

TM-OH.1 is well suited as a precursor for a cathode active material for lithium ion batteries.

FIG. 4: manganese content of TM-OH.1 in the core and outer surface of the particles as a function of the diameter of the secondary particles. Manganese content was determined on SEM particle cross-sections by EDS measurement.

FIG. 5: the nickel content of TM-OH.1 in the core and outer surface of the particles as a function of the diameter of the secondary particles. Manganese content was determined on SEM particle cross-sections by EDS measurement.

I.2 preparation of the precursor TM-OH.2

To the vessel was added 8 liters of (NH) as described above₄)₂SO₄An aqueous solution. The pH of the solution was then adjusted to 12.05 with 25 wt% aqueous sodium hydroxide.

The temperature of the vessel was set to 45 ℃. The stirrer elements were started and operated constantly at 530rpm (average input 6W/l). Mixing NiSO₄、CoSO₄And MnSO₄Was introduced into a vessel simultaneously with an aqueous solution of sodium hydroxide (25% by weight NaOH) and an aqueous ammonia solution (25% by weight ammonia) in a molar ratio of 6:2:2, total metal concentration of 1.65mol/kg, through a coaxial mixer. The aqueous metal solution was introduced through the inner tube of the coaxial mixer, and the aqueous sodium hydroxide solution and the aqueous ammonia solution were introduced through the outer tube of the coaxial mixer. The distance between the outlets of the two coaxially arranged tubes is in the range of 7 mm.

The molar ratio of ammonia to metal was adjusted to 0.3. The sum of the volume flows was set to adjust the mean residence time to 6 hours. The flow rate of NaOH was adjusted through the pH adjustment loop to maintain the pH in the vessel at a constant value of 12.05. The apparatus was operated continuously, keeping the liquid level in the reaction vessel constant. The mixed hydroxides of Ni, Co and Mn were collected by free overflow from the vessel. The resulting slurry contained about 120g/l of mixed hydroxide of Ni, Co and Mn with an average particle size (D50) of 10.5 μm, TM-OH.2. The bulk density and BET surface area of the precursor TM-OH.2 were 2.07g/l and 12.48m, respectively²(ii) in terms of/g. The total pore volume and average pore size is 0.044ml/g andat least 70% by volume of the secondary particles of TM-OH.2 consist of primary particles which are substantially radially oriented. TM — oh.2 is well suited as a precursor for lithium ion battery cathode active materials.

I.3 preparation of the precursor TM-OH.3

To the vessel was added 8 liters of (NH) as described above₄)₂SO₄An aqueous solution. The pH of the solution was then adjusted to 12.05 with 25 wt% aqueous sodium hydroxide.

The temperature of the vessel was set at 45 ℃ and the stirrer elements were started and operated constantly at 530rpm (average input 6W/l). Mixing NiSO₄、CoSO₄And MnSO₄Was introduced into a stirred vessel simultaneously through a coaxial mixer with an aqueous solution of sodium hydroxide (25 wt% NaOH) and an aqueous ammonia solution (25 wt% ammonia) at a molar ratio of 6:2:2, total metal concentration of 1.65 mol/kg. The aqueous metal solution was introduced through the inner tube of the coaxial mixer, and the aqueous sodium hydroxide solution and the aqueous ammonia solution were introduced through the outer tube of the coaxial mixer. The distance between the outlets of the two coaxially arranged tubes is in the range of 7 mm.

The molar ratio of ammonia to metal was adjusted to 0.35. The sum of the volume flows was set to adjust the mean residence time to 6 hours. The flow rate of NaOH was adjusted through the pH adjustment loop to maintain the pH 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. The mixed hydroxides of Ni, Co and Mn were collected by free overflow from the vessel. The resulting slurry contained about 120g/l of mixed hydroxide of Ni, Co and Mn with an average particle size (D50) of 9.8 μm, TM-OH.3. The bulk density and BET surface area of TM-OH.3 were 2.0g/l and 11.3m, respectively²(ii) in terms of/g. The total pore volume and average pore size of TM-OH.3 was 0.037ml/g andat least 70% by volume of the secondary particles of TM-OH.3 consist of primary particles which are substantially radially oriented. TM-OH.3 is very suitableTo cooperate as a precursor for a cathode active material of a lithium ion battery.

I.4 preparation of the precursor TM-OH.4

To the vessel was added 8 liters of (NH) as described above₄)₂SO₄An aqueous solution. The pH of the solution was then adjusted to 11.5 with 25 wt% aqueous sodium hydroxide.

The temperature of the vessel was set to 55 ℃. The stirrer elements were started and operated constantly at 530rpm (average input 6W/l). Mixing NiSO₄、CoSO₄And MnSO₄Was introduced into a stirred vessel simultaneously through a coaxial mixer with an aqueous solution of sodium hydroxide (25% by weight NaOH) and an aqueous ammonia solution (25% by weight ammonia) at a molar ratio of 87:5:8 with a total metal concentration of 1.65 mol/kg. The aqueous metal solution was introduced through the inner tube of the coaxial mixer, and the aqueous sodium hydroxide solution and the aqueous ammonia solution were introduced through the outer tube of the coaxial mixer. The distance between the outlets of the two coaxially arranged tubes is in the range of 5 mm.

The molar ratio of ammonia to metal was adjusted to 0.2. The sum of the volume flows was set to adjust the mean residence time to 6 hours. The flow rate of NaOH was adjusted through the pH adjustment loop to maintain the pH in the vessel at a constant value of 11.5. The apparatus was operated continuously, keeping the liquid level in the vessel constant. The mixed hydroxides of Ni, Co and Mn were collected by free overflow from the vessel. The resulting slurry contained about 120g/l of mixed hydroxide of Ni, Co and Mn with an average particle size (D50) of 12.3 μm, TM-OH.4. The bulk density and BET surface area of TM-OH.4 were 1.91g/l and 17.94m, respectively²(ii) in terms of/g. The total pore volume and mean pore size of TM-OH.4 was 0.045ml/g andat least 70% by volume of the secondary particles of TM-OH.4 consist of primary particles which are substantially radially oriented.

In addition, the outer surface of the secondary particles contained on average 3.7% less nickel than the particle core. On the other hand, the manganese concentration in the particle surface was 4.9% higher on average than in the particle core, while the small secondary particles contained more manganese than the large secondary particles (see fig. 6 and 7). The data was generated on SEM cross-sectional micrographs using EDS measurements.

TM — oh.4 is well suited as a precursor for lithium ion battery cathode active materials.

I.5 preparation of the precursor TM-OH.5

To a 50L stirred vessel equipped with baffles and a 0.21m diameter cross arm stirrer and a coaxial mixer (see FIG. 1) was added 40 liters of the above (NH)₄)₂SO₄An aqueous solution. The pH of the solution was then adjusted to 11.6 with 25 wt% aqueous sodium hydroxide. The in-line mixer was located in the vessel such that the outlet of the in-line mixer was located about 10cm below the liquid level. The coaxial mixer consists of two coaxially arranged stainless steel tubes. The inner diameter and the outer diameter of the inner circular tube are respectively 1mm and 4 mm. The inner diameter and the outer diameter of the outer circular tube are respectively 2mm and 6 mm.

The temperature of the vessel was set to 55 ℃. The stirrer elements were started and operated constantly at 420rpm (average input 12.6W/l). Mixing NiSO₄、CoSO₄And MnSO₄Was introduced into a vessel simultaneously with an aqueous solution of sodium hydroxide (25% by weight NaOH) and an aqueous ammonia solution (25% by weight ammonia) through a coaxial mixer (molar ratio: 83:12:5, total metal concentration 1.65 mol/kg). The aqueous metal solution was introduced through the inner tube of the coaxial mixer, and the aqueous sodium hydroxide solution and the aqueous ammonia solution were introduced through the outer tube of the coaxial mixer. The distance between the outlets of the two coaxially arranged tubes is in the range of 15 mm.

The molar ratio of ammonia to metal was adjusted to 0.265. The sum of the volume flows was set to adjust the average residence time to 5 hours. The flow rate of NaOH was adjusted through the pH adjustment loop to maintain the pH in the vessel at a constant value of 11.58. The apparatus was operated continuously, keeping the liquid level in the vessel constant. The mixed hydroxides of Ni, Co and Mn were collected by free overflow from the vessel. The resulting product slurry contained about 120g/l of mixed hydroxides of Ni, Co and Mn, with an average particle size (D50) of 10.5 μm, TM-OH.5. The bulk density and BET surface area of TM-OH.5 were 1.95g/l and 23.1m, respectively²(ii) in terms of/g. The total pore volume and average pore size of TM-OH.5 was 0.074ml/g andat least 70% by volume of the secondary particles of TM-OH.5 consist of primary particles which are substantially radially oriented. TM-oh.5 is well suited as a precursor for lithium ion battery cathode active materials.

I.6 preparation of the precursor TM-OH.6

To a 50L stirred vessel equipped with baffles and a 0.21m diameter cross arm stirrer and a coaxial mixer (see FIG. 1) was added 40 liters of the above (NH)₄)₂SO₄An aqueous solution. The pH of the solution was then adjusted to 11.9 with 25 wt% aqueous sodium hydroxide. The in-line mixer was located in the vessel such that the outlet of the in-line mixer was located about 10cm below the liquid level. The coaxial mixer consists of two coaxially arranged stainless steel tubes. The inner diameter and the outer diameter of the inner circular tube are respectively 1mm and 4 mm. The inner diameter and the outer diameter of the outer circular tube are respectively 2mm and 6 mm.

The temperature of the vessel was set to 55 ℃. The stirrer elements were started and operated constantly at 420rpm (average input 12.6W/l). Mixing NiSO₄、CoSO₄And MnSO₄Was introduced into a vessel simultaneously with an aqueous solution of sodium hydroxide (25% by weight NaOH) and an aqueous ammonia solution (25% by weight ammonia) through a coaxial mixer (molar ratio: 83:12:5, total metal concentration 1.65 mol/kg). The aqueous metal solution was introduced through the inner tube of the coaxial mixer, and the aqueous sodium hydroxide solution and the aqueous ammonia solution were introduced through the outer tube of the coaxial mixer. The distance between the outlets of the two coaxially arranged tubes is in the range of 30 mm.

The molar ratio of ammonia to metal was adjusted to 0.265. The sum of the volume flows was set to adjust the average residence time to 5 hours. The flow rate of NaOH was adjusted through the pH adjustment loop to maintain the pH in the vessel at a constant value of 11.9. The apparatus was operated continuously, keeping the liquid level in the reaction vessel constant. The mixed hydroxides of Ni, Co and Mn were collected by free overflow from the vessel. The resulting slurry contained about 120g/l of mixed hydroxide of Ni, Co and Mn with an average particle size (D50) of 12.3 μm, TM-OH.6. The bulk density and BET surface area of TM-OH.6 were 1.93g/l and 20.91m, respectively²(ii) in terms of/g. The total pore volume and mean pore size of TM-OH.6 was 0.066ml/g andat least 70% by volume of the secondary particles of TM-OH.6 consist of primary particles which are substantially radially oriented. TM — oh.6 is well suited as a precursor for lithium ion battery cathode active materials.

I.7 preparation of the precursor TM-OH.7

To a 50L stirred vessel (see FIG. 1) equipped with baffles and a cross-arm stirrer and coaxial mixer having a diameter of 0.21m, 40 liters of the above (NH) were charged₄)₂SO₄An aqueous solution. The pH of the solution was then adjusted to 11.9 with 25 wt% aqueous sodium hydroxide. The in-line mixer was located in the vessel such that the outlet of the in-line mixer was located about 10cm below the liquid level. The coaxial mixer consists of two coaxially arranged tubes made of FEP. The inner diameter and the outer diameter of the inner circular tube are respectively 1.5mm and 3.2 mm. The inner diameter and the outer diameter of the outer circular tube are respectively 4mm and 6 mm.

The temperature of the vessel was set to 55 ℃. The stirrer elements were started and operated constantly at 420rpm (average input 12.6W/l). Mixing NiSO₄、CoSO₄And MnSO₄Was introduced into a vessel simultaneously with an aqueous solution of sodium hydroxide (25% by weight NaOH) and an aqueous ammonia solution (25% by weight ammonia) in a molar ratio of 83:12:5 at a total transition metal concentration of 1.65mol/kg through a coaxial mixer. The aqueous metal solution was introduced through the inner tube of the coaxial mixer, and the aqueous sodium hydroxide solution and the aqueous ammonia solution were introduced through the outer tube of the coaxial mixer. The distance between the outlets of the two coaxially arranged tubes is in the range of 30 mm.

The molar ratio of ammonia to metal was adjusted to 0.265. The sum of the volume flows was set to adjust the average residence time to 5 hours. The flow rate of NaOH was adjusted through the pH adjustment loop to maintain the pH in the vessel at a constant value of 11.9. The apparatus was operated continuously, keeping the liquid level in the reaction vessel constant. The mixed hydroxides of Ni, Co and Mn were collected by free overflow from the vessel. The resulting slurry contained about 120g/l of mixed hydroxide of Ni, Co and Mn with an average particle size (D50) of 12.3 μm, TM-OH.7. The bulk density and BET surface area of TM-OH.7 were 1.93g/l and 21.3m, respectively²(ii) in terms of/g. TM-OH.7 has a total pore volume and an average pore size of 0.066 ml-g andat least 70% by volume of the secondary particles of TM-OH.7 consist of primary particles which are substantially radially oriented. TM-OH.7 is well suited as a precursor for a cathode active material for lithium ion batteries.

I.8 preparation of the precursor TM-OH.8

To a 50L stirred vessel equipped with baffles and a 0.21m diameter cross arm stirrer and a coaxial mixer (see FIG. 1) was added 40 liters of the above (NH)₄)₂SO₄An aqueous solution. The pH of the solution was then adjusted to 11.88 with 25 wt% aqueous sodium hydroxide. The in-line mixer was located in the vessel such that the outlet of the in-line mixer was located about 10cm below the liquid level. The coaxial mixer consists of two coaxially arranged tubes made of FEP. The inner diameter and the outer diameter of the inner circular tube are respectively 1.5mm and 3.2 mm. The inner diameter and the outer diameter of the outer circular tube are respectively 4mm and 6 mm.

The temperature of the vessel was set to 55 ℃. The stirrer elements were started and operated constantly at 420rpm (average input 12.6W/l). Mixing NiSO₄、CoSO₄And MnSO₄Was introduced into a vessel simultaneously with an aqueous solution of sodium hydroxide (25% by weight NaOH) and an aqueous ammonia solution (25% by weight ammonia) through a coaxial mixer (molar ratio: 83:12:5, total metal concentration 1.65 mol/kg). The aqueous metal solution was introduced through the inner tube of the coaxial mixer, and the aqueous sodium hydroxide solution and the aqueous ammonia solution were introduced through the outer tube of the coaxial mixer. The distance between the outlets of the two coaxially arranged tubes is in the range of 30 mm.

The molar ratio of ammonia to metal was adjusted to 0.265. The sum of the volume flows was set to adjust the average residence time to 5 hours. The flow rate of NaOH was adjusted through the pH adjustment loop to maintain the pH in the vessel at a constant value of 11.9. The apparatus was operated continuously, keeping the liquid level in the reaction vessel constant. The mixed hydroxides of Ni, Co and Mn were collected by free overflow from the vessel. The resulting slurry contained about 120g/l of mixed hydroxide of Ni, Co and Mn with an average particle size (D50) of 12.0 μm, TM-OH.8. The bulk density and BET surface area of TM-OH.8 were 1.92g/l and 20.58m, respectively²(ii) in terms of/g. At least 70% by volume of the secondary particles of TM-OH.8 consist of primary particles which are substantially radially oriented. TM — oh.8 is well suited as a precursor for lithium ion battery cathode active materials.

I.9 comparative example-preparation of comparative precursor C-TM-OH.9

To a 50L stirred vessel (see FIG. 1) equipped with baffles and a cross-arm stirrer and coaxial mixer having a diameter of 0.21m, 40 liters of the above (NH) were charged₄)₂SO₄An aqueous solution. The pH of the solution was then adjusted to 11.4 with 25 wt% aqueous sodium hydroxide. In this experiment, the feed was not added through a coaxial mixer. In contrast, the transition metal feed was metered via a dip tube having an internal diameter of 4mm near the stirrer element, while the NaOH and ammonia were metered via separate dip tubes having an internal diameter of 4mm near the stirrer element. The distance between the outlets of the two tubes is greater than 10 times the internal hydraulic diameter of the base metering tube.

The temperature of the vessel was set to 55 ℃. The stirrer elements were started and operated constantly at 420rpm (average input 12.6W/l). Simultaneously introducing NiSO₄、CoSO₄And MnSO₄An aqueous solution of (1.65 mol/kg in total metal concentration, molar ratio: 83:12: 5), an aqueous sodium hydroxide solution (25 wt% NaOH) and an aqueous ammonia solution (25 wt% ammonia).

The molar ratio of ammonia to transition metal was adjusted to 0.115. The sum of the volume flows was set to adjust the average residence time to 5 hours. The flow rate of NaOH was adjusted through the pH adjustment loop to maintain the pH in the vessel at a constant value of 11.4. The apparatus was operated continuously, keeping the liquid level in the reaction vessel constant. The mixed hydroxides of Ni, Co and Mn were collected by free overflow from the vessel. The resulting slurry contained about 120g/l of 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 a precursor for the cathode active material of comparative lithium ion batteries. I.10 comparative example-preparation of comparative precursor C-TM-OH.10

To a 50L stirred vessel (see FIG. 1) equipped with baffles and a cross-arm stirrer and coaxial mixer having a diameter of 0.21m, 40 liters of the above (NH) were charged₄)₂SO₄An aqueous solution.The pH of the solution was then adjusted to 12.34 with 25 wt% aqueous sodium hydroxide. In this experiment, the feed was not metered in via a coaxial mixer. In contrast, the transition metal feed was metered via a dip tube having an internal diameter of 4mm near the stirrer element, while the NaOH and ammonia were metered via separate dip tubes having an internal diameter of 4mm near the stirrer element. The distance between the outlets of the two tubes is greater than 10 times the internal hydraulic diameter of the base metering tube.

The temperature of the vessel was set to 55 ℃. The stirrer elements were started and operated constantly at 420rpm (average input 12.6W/l). With the introduction of a catalyst containing NiSO₄、CoSO₄And MnSO₄(molar ratio 87:5:8, total metal concentration 1.65mol/kg), aqueous sodium hydroxide (25 wt% NaOH) and aqueous ammonia (25 wt% ammonia).

The molar ratio of ammonia to metal was adjusted to 0.4. The sum of the volume flows was set to adjust the average residence time to 5 hours. The flow rate of NaOH was adjusted through the pH adjustment loop to maintain the pH in the vessel at a constant value of 12.34. The apparatus was operated continuously, keeping the liquid level in the reaction vessel constant. The mixed hydroxides of Ni, Co and Mn were collected by free overflow from the vessel. The resulting slurry contained about 120g/l of 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 a precursor for the cathode active material of comparative lithium ion batteries. Preparation of cathode active Material of the present invention

II.1 preparation of the cathode Material CAM.1 according to the invention made of TM-OH.1

The precursor TM-OH.1 is mixed with LiOH monohydrate and crystalline Al₂O₃The mixture was mixed at a concentration of 0.3 mol% of Al relative to Ni + Co + Mn + Al and a molar ratio of Li/(Ni + Co + Mn + Al) of 1.02. The resulting mixture was heated to 820 ℃ and held in a forced oxygen flow for 8 hours. After natural cooling, the resulting calcined powder was deagglomerated and sieved through a 32 μm vibrating sieve. A cathode active material cam.1 was obtained.

The first 0.1C discharge of cam.1 measured in the half cell reached 187.0 mAh/g. The capacity after 100 cycles in the half-cell reached 99.8% respectively.

II.2 preparation of the cathode Material CAM.4 according to the invention made of TM-OH.4

The precursor TM-OH.4 is reacted with LiOH monohydrate and crystalline Al₂O₃The mixture was mixed at a concentration of 0.3 mol% of Al relative to Ni + Co + Mn + Al and a molar ratio of Li/(Ni + Co + Mn + Al) of 1.02. The resulting mixture was heated to 820 ℃ and held for 5 hours in a forced oxygen flow. After natural cooling, the resulting calcined powder was deagglomerated and sieved through a 32 μm vibrating sieve. The cathode active material cam.4 was obtained.

The first 0.1C discharge of cam.4 measured in the half cell reached 186.0 mAh/g. The capacity after 100 cycles in the half cell reached 98.5% respectively.

II.3 preparation of the cathode Material CAM.5 according to the invention made of TM-OH.5

The precursor TM-OH.5 was mixed with LiOH monohydrate in a molar ratio Li/(Ni + Co + Mn) of 1.02. The resulting mixture was heated to 760 ℃ and held in a forced oxygen flow for 6 hours. After natural cooling, the resulting calcined powder was deagglomerated and sieved through a 32 μm vibrating sieve. A cathode active material cam.5 was obtained.

The median primary particle diameter was 0.24 μm, the span was 0.92, and the median axial ratio was 1.88.

The primary particles of cam.5 have an orientation that deviates from the ideal radial orientation by 2.8 degrees or less for 20%, 10.5 degrees or less for 50%, and even 80% or less. Fig. 3B shows an exemplary micrograph of an SEM cross-section of cam.5 of the present invention.

The first 0.1C discharge of cam.5 measured in the half cell reached 205.8 mAh/g. After 50 and 100 1C cycles in the full cell, the capacity reached 97.9% and 90.6%, respectively.

II.4 preparation of the cathode material CAM.8 according to the invention made of TM-OH.8

The precursor TM-OH.8 is mixed with LiOH monohydrate and TiO₂And Zr (OH)₄Mixed at a concentration of 0.17 mol% Zr and 0.17 mol% Ti relative to Ni + Co + Mn + Zr + Ti and a molar ratio of Li/(Ni + Co + Mn + Zr + Ti) of 1.05. The mixture was heated to 780 ℃ and held in a forced oxygen flow for 6 hours. After natural cooling, the resulting calcined powder was deagglomerated and sieved through a 32 μm vibrating sieve. The cathode active material cam.8 was obtained.

The median primary particle diameter was 0.37 μm, the span was 1.10, and the median axial ratio was 1.56. 20% of the primary particles have an orientation that deviates from the ideal radial orientation by 4.3 degrees or less, 50% by 10.7 degrees or less, and even 80% by 31.0 degrees or less.

The first 0.1C discharge of cam.8 measured in the half cell reached 204.7 mAh/g. After 50 and 100 1C cycles in the full cell, the capacity reached 96.3% and 94.1%, respectively.

II.5 comparative example-preparation of cathode Material C-CAM.10 made of C-TM-OH.10

The precursor TM-OH.10 is mixed with LiOH monohydrate and TiO₂And Zr (OH)₄Were mixed at a concentration of 0.17 mol% Zr and 0.17 mol% Ti relative to Ni + Co + Mn + Zr + Ti and a molar ratio of Li/(Ni + Co + Mn + Zr + Ti) of 1.04. The resulting mixture was heated to 760 ℃ and held for 5 hours in a forced oxygen flow. After natural cooling, the resulting calcined powder was deagglomerated and sieved through a 32 μm vibrating sieve. The cathode active material C-cam.10 was obtained.

The median primary particle diameter was 0.27 μm, the span was 1.27, and the median axial ratio was 1.44. Fig. 3A shows an exemplary micrograph of an SEM cross section of comparative cathode active material C-cam.10.

20% of the primary particles have an orientation that deviates from the ideal radial orientation by 9.0 degrees or less, 50% by 20.3 degrees or less, and 80% by 45.0 degrees or less.

The first 0.1C discharge of C-CAM.10 measured in the half cell reached 203.7 mAh/g. After 50 and 100 1C cycles in the full cell, the capacity reached 94.2% and 86.5%, respectively.

Electrochemical testing

Percentages are by weight unless otherwise indicated. In the case of a cathode, the percentage refers to the entire cathode minus the current collector.

III.1 preparation of cathodes

Preparing an electrode: the electrode contained 93% of the corresponding cathode active material, 1.5% of carbon black (Super C65), 2.5% of graphite (SFG6L) and 3% of binder (polyvinylidene fluoride, Solef 5130). The slurry was mixed in N-methyl-2-pyrrolidone and cast onto aluminum foil by doctor blade. After drying the electrodes in vacuo at 105 ℃ for 6 hours, the round electrodes were punched, weighed and dried in vacuo at 120 ℃ overnight before entering an Ar-filled glove box.

III.2 electrolytes

Electrolyte 1: 1M LiPF in Ethylene Carbonate (EC): dimethyl carbonate (DMC) in a 1:1 weight ratio₆Used as an electrolyte.

Electrolyte 2: 1M LiPF in 1:1 weight ratio EC Ethylmethyl carbonate (EMC) containing 2 wt.% vinylene carbonate₆。

III.3 Anode

0.58mm thick lithium foil

III.3 preparation of half-cell button cell

A button-type electrochemical cell was assembled in an argon-filled glove box. The diameter of 14mm (the load is 11.0-0.4 mg cm)^-2) The positive electrode was separated from the anode by a glass fiber membrane (Whatman GF/D). The half cell used electrolyte 1 in an amount of 100. mu.L.

The test was performed using a Maccor 4000 system. The cell was cycled galvanostatically between 3-4.3V versus Li, then potentiostatically at 4.3V for 30 minutes or until the current was below 0.01C current. The cells were placed in a Binder climate chamber at a specified temperature of 25 ℃. The cell was cycled 129 times, first 2 cycles at a rate of 0.1C/0.1C (charge/discharge, hereinafter) to determine capacity; then 5 cycles at a rate of 0.1C/0.1C to make adjustments; then 6 cycles at a rate of 0.5C/0.1C, 0.5C/0.2C, 0.5C/0.5C, 0.5C/1C, 0.5C/2C, 0.5C/3C to determine discharge rate capability; then 2 cycles at a rate of 0.5C/0.1C to determine capacity; then 50 cycles were performed at a rate of 0.5C/0.1C to determine the cycling stability; then 2 cycles at a rate of 0.5C/0.1C to determine capacity; then 50 cycles were performed at a rate of 0.5C/0.1C to determine the cycling stability; then, the capacitance was measured by performing 2 cycles at a rate of 0.5C/0.1C, and finally, the cycle stability was measured by performing 10 cycles at a rate of 0.5C/0.1C.

III.4 preparation of full-cell button cell

Full cell electrochemical measurements: a button-type electrochemical cell was assembled in an argon-filled glove box. A positive electrode (supporting amount: 11.3. multidot.1.1 mg cm) having a diameter of 17.5mm was placed in the cell^-2) Separated from the 18.5mm graphite anode by a glass fiber membrane (Whatman GF/D). The amount of electrolyte 2 was 300. mu.l. The cells were cycled at constant current between 2.7-4.20V at 1C rate and 45 ℃ using a Maccor 4000 battery cycler with a potentiostatic charging step at 4.2V for 1 hour or until the current dropped below 0.02C.

During the resistance measurement (every 25 cycles at 25 ℃), the battery was charged in the same way as the cycles. Then, the battery was discharged at 1C for 30 minutes to reach a 50% state of charge. To balance the cell, a 30 second open circuit step was followed. Finally, a 2.5C discharge current was applied for 30 seconds to measure the resistance. At the end of the current pulse, the cell was again equilibrated in open circuit for 30 seconds and further discharged at 1C to 2.7V relative to the graphite.

To calculate the resistance, the voltage V0s before applying the 2.5C pulse current and the voltage V10s after applying the 10s 2.5C pulse current, and the 2.5C current value (I, in a) were taken. The resistance (S: electrode area, V: voltage, I: 2.5C pulse current) was calculated according to equation 1:

r ═ (V0S-V10S)/I × S (equation 1).