PROCESS FOR MAKING A PARTICULATE (OXY)HYDROXIDE OR OXIDE

Abstract

Disclosed herein is a process for making a particulate (oxy)hydroxide, carbonate, or oxide of TM which includes nickel and at least one metal selected from the group consisting of cobalt, manganese, and aluminum. The process includes providing an aqueous solution (?1) containing a water-soluble salt of Ni, one of an aqueous solution (?2) containing a water-soluble salt of Co, an aqueous solution (?3) containing a water-soluble salt of Mn, or an aqueous solution (?4) containing a water-soluble compound of Al, an aqueous solution (?) containing an alkali metal hydroxide or carbonate and, optionally, an aqueous solution (?) containing ammonia or an organic acid or its alkali metal salt, combining solution (?1) and solution (?) and at least one of solutions (?2), (?3), (?4), and, if applicable, solution (?), in different locations of a continuous reactor, and removing the particles from the liquid by a solid-liquid separation method.

Claims

1. A process for making a particulate (oxy)hydroxide or carbonate or oxide of TM, wherein TM comprises nickel and at least one metal selected from the group consisting of cobalt and manganese and aluminum, the process comprising: (a) providing an aqueous solution (?1) containing a water-soluble salt of Ni and an aqueous solution (?2) containing a water-soluble salt of Co or an aqueous solution (?3) containing a water-soluble salt of Mn or an aqueous solution (?4) containing a water-soluble compound of Al, and an aqueous solution (?) containing an alkali metal hydroxide or carbonate and, optionally, an aqueous solution (?) containing ammonia or an organic acid or its alkali metal salt, (b) combining solution (?1) and solution (?) and at least one of solutions (?2) or (?3) or (?4), and, if applicable, solution (?), in a continuous reactor, thereby creating solid particles of a hydroxide or carbonate of TM, wherein such solutions are introduced into said continuous reactor in different locations, and (c) separating the particles from step (b) from the liquid phase by a solid-liquid separation method, and wherein the distances between the locations of introduction of solutions (?1) and (?2) or (?3) or (?4) are equal or larger than six times the hydraulic diameter of the tip of the inlet of solution (?1).

2. The process according to claim 1 wherein step (b) is performed in a continuous stirred tank reactor.

3. The process according to claim 1 wherein the particulate mixed transition metal precursor is selected from the group consisting of (oxy)hydroxides, carbonates, and oxides of TM, wherein TM is a combination of metals according to general formula (I)
(Ni.sub.aCo.sub.bMn.sub.c).sub.1-dM.sub.d(I) wherein a is in the range of from 0.5 to 0.95, b is zero or in the range of from 0.025 to 0.5, c is in the range of from zero to 0.2, and d is in the range of from zero to 0.1, M is selected from the group consisting of Mg, Al, Ti, Zr, Mo, W, and Nb, and a+b+c=1, and b+c>zero or M includes Al and d>zero.

4. The process according to claim 1 wherein the distance between the outlet of the tank reactor and the tip of the inlet of solution (?2) or (?3) or (?4) is at most fifteen times the hydraulic diameter of the tip of the respective inlet while the distance between the outlet of the reactor and the tip of the inlet of solution (?1) is at least fifteen times the hydraulic diameter of the tip of the inlet of solution (?1).

5. The process according to claim 1 wherein in step (b), the velocities of addition of solutions (?1) and (?2) or (?3) or (?4) are independently from each other varied in the range from 0.1 to 10 m/s.

6. The process according to claim 1 wherein in step (b) a water-soluble compound of a metal M selected from the group consisting of Mg, Ti, Zr, Mo, W, and Nb, is added as an aqueous solution (?).

7. The process according to claim 1 wherein the organic acid in solution (?) is selected from the group consisting of tartaric acid, citric acid, and glycine.

8. The process according to claim 1 wherein said process includes the additional step (d) of thermally treating the solid residue from step (c) in a rotary kiln or a flash calciner.

9. A particulate (oxy)hydroxide of TM comprising a brucite structure, wherein TM contains nickel and at least one metal selected from the group consisting of cobalt, manganese and aluminum, and wherein such particulate (oxy)hydroxide has a core-shell structure, in which at least one component selected from the group consisting of cobalt, manganese, and aluminum is enriched in the shell, and wherein said brucite structure display C19 stacking faults leading to local CdCl.sub.2 structural areas that are induced by molecules or ions intercalated into the crystal lattice selected from the group consisting of water, carbonate, sulfate, and counterions of organic acids selected from the group consisting of tartaric acid, citric acid, and glycine, with a transition probability for an intercalation layer in the range of from 2 to 10%, and wherein said (oxy)hydroxide has a particle diameter distribution with a span defined as [(D90)?(D10)]/(D50) in the range of from 0.9 to 2.0.

10. The particulate (oxy)hydroxide according to claim 9 wherein TM is a combination of metals according to general formula (I)
(Ni.sub.aCo.sub.bMn.sub.c).sub.1-dM.sub.d(I) wherein a is in the range of from 0.5 to 0.95, b is zero or in the range of from 0.025 to 0.5, c is in the range of from zero to 0.2, and d is in the range of from zero to 0.1, M is selected from the group consisting of Mg, Al, Ti, Zr, Mo, W, and Nb, and a+b+c=1, and b+c>zero or M includes Al and d>zero.

11. The particulate (oxy)hydroxide according to claim 9, wherein the at least one component selected from the group consisting of cobalt, manganese, and aluminum is enriched in the shell of the secondary particle by at least 5 mol-%, referring to the sum of nickel, cobalt, manganese and aluminum and compared to the core.

12. The particulate (oxy)hydroxide according to claim 9 wherein at least 60 vol.-% of the secondary particles consist of primary particles that are essentially radially oriented, wherein primary particles that are essentially radially oriented are selected from the group consisting of radially oriented primary particles and primary particles that show a deviation to a perfectly radial orientation of at most 11 degrees in an SEM analysis.

13. The particulate (oxy)hydroxide according to claim 9 having a moisture content in the range of from 100 to 5,000 ppm, determined by Karl-Fischer titration.

14. A particulate oxide of TM wherein TM contains nickel and at least one metal selected from the group consisting of cobalt, manganese, and aluminum and wherein such particulate oxide has a core-shell structure, in which at least one component selected from the group consisting of cobalt, manganese, and aluminum is enriched in the shell, has a particle diameter distribution with a span defined as [(D90)?(D10)]/(D50) in the range of from 0.9 to 2.0, a specific surface (BET) in the range of from 20 to 200 m.sup.2/g and an average crystallite size in the range of from 100 to 300 ?.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0120] A: reaction vessel [0121] B: stirrer blades [0122] C: feed inlet for aqueous solution (?1.1) [0123] D: ammonia feed inlet [0124] E: sodium hydroxide feed inlet, solution (?.1) [0125] F: aqueous cobalt sulfate solution feed inlet, solution (?2.1) [0126] G: baffle

WORKING EXAMPLE

[0127] Percentages refer to % by weight unless expressly noted otherwise. All pH values were determined at 23? C.

[0128] The co-precipitation reactions were performed in a 250-ml stirred tank reactor (Reactor 1), see FIG. 1, equipped with an overflow system and four dosing inlets as well as a pH value regulation circuit (not shown in the drawing). The four dosing inlets were arranged in a circuit around the stirrer. Feed inlet C had the closest proximity to the overflow. Both inlet pipes C and F were arranged in a distance of 100 times the hydraulic diameter measured from the inlet pipes.

[0129] For determination of the element distribution over the particle diameter, inventive precursor was embedded in Epofix resin (Struers, Copenhagen, Denmark). Ultra-thin samples (?100 nm) for Transmission Electron Microscopy (TEM) were prepared by ultramicrotomy and transferred to TEM sample carrier grids. The samples were imaged by TEM using Tecnai Osiris and Themis Z3.1 machines (Thermo-Fisher, Waltham, USA) operated at 200/300 keV under HAADF-STEM conditions. Chemical composition maps were acquired by energy-dispersive x-ray spectroscopy (EDXS) using a SuperX G2 detector. Images and elemental maps were evaluated using the Velox (Thermo-Fisher) as well as the Esprit (Bruker, Billerica, USA) software packages.

[0130] Step (a.1): The following aqueous solutions were provided by dissolving the respective compound in water: [0131] Solution (?1.1): NiSO.sub.4, 1.65 ml/kg in water [0132] Solution (?1.2): CoSO.sub.4, 1.65 ml/kg in water [0133] Solution (?.1): 25% by weight NaOH in water [0134] Solution (?.1): 25% by weight NH 3 in water

[0135] Step (b.1):

[0136] Reactor 1 was charged with 6 mL of solution (?.1). Then, the pH value of the solution was adjusted to 12.10 (if measured at 23? C.) using solution (?.1). Then, the temperature of the Reactor 1 was set to 55? C. The stirrer was constantly operated at 700 rpm. Simultaneously, solution (?1.1) was introduced through inlet C and solution containing (?2.1) through inlet F, solution (?.1) through inlet E and solution (?.1) through inlet D. The molar ratio between nickel and cobalt was adjusted to 55:45.

[0137] The molar ratio between ammonia and the sum of nickel and cobalt was adjusted to 0.25. The sum of volume flows was set to adjust the mean residence time to 2.5 hours. The flow rate of (?.1) was adjusted by a pH regulation circuit to keep the pH value in the vessel at a constant value of 12.10. Reactor 1 was operated continuously keeping the liquid level in the vessel constant. A mixed hydroxide of Ni and Co, TM-OH.1, was collected via overflow from the vessel. The resulting product slurry contained about 120 g/l mixed hydroxide TM-OH.1 with an average particle size (D50) of 8.14 ?m and a span of 1.26.

[0138] Due to the addition of the Co closer to the overflow, Co is enriched in the outer part of the particles of TM-OH.1 but not in the shell.

[0139] Step (c.1): TM-OH.1 particles were collected, filtered, washed with deionized water, dried and sieved using a mesh size of 30 ?m. The residual Sulphur content of the dried TM-OH.1 was 0.21 wt %, and TM-OH.1 exhibited a specific surface (BET) of 4.41 m.sup.2/g. Further, the particles of TM-OH.1 exhibited a Ni-rich core, followed by a Co enriched transition shell and again a Ni-rich terminating shell which was enriched by approximately 5-7 mol % more Ni compared Nickel content in the Co enriched transition shell as verified by TEM-EDX (see FIGS. 2 and 3). By application of stacking fault modeling on measured XRD diffraction patterns the average crystallite size was determined to 177 ?. The transition probability p.sub.car, for the occurrence of a C19 stacking fault by an intercalation layer between the brucite-type layers consisting of sulphate ions was determined to p.sub.car=6.2% based on the corresponding X-ray diffraction pattern in FIG. 4. The stacking faults lead to local CdCl.sub.2 structural areas.

[0140] For conversion to a dehydrated precursor, TM-OH.1 was subjected to thermal treatment at 500? C. in a Linn oven in the absence of any lithium source to yield mixed oxide particles, TMO.1. The specific surface (BET) of TMO.1 was 46.19 m.sup.2/g. TMO.1 exhibited an average crystallite size of 152 ? which was extracted from the XRD pattern in FIG. 5. The previously mentioned concentration gradient within the secondary particles of TMO.1 was retained despite heat treatment. TMO.1 exhibited a Ni-rich core, followed by a Co-rich transition shell and again a Ni-rich shell as verified by TEM-EDX (see FIGS. 6 and 7).