Method for producing an aqueous slurry and method for producing a hydroxide powder from the aqueous slurry

Abstract

Generally, the present invention relates to metal hydroxides that can be used as precursors for cathode active materials for secondary batteries and methods for making the same. In particular, the present invention relates to, but is not limited to, a method for making an aqueous slurry containing a hydroxide or oxyhydroxide of at least one metal element, a method for making hydroxide or oxyhydroxide powders from the aqueous slurry, and the use of the aqueous slurry or hydroxide or oxyhydroxide powders to make cathode active materials for secondary batteries.

Description

[Technical Field]

[0001] Generally, the present invention relates to metal hydroxides that can be used as precursors of cathode active materials for secondary batteries and methods for making the same. In particular, the present invention relates to, but is not limited to, a method for making an aqueous slurry containing a hydroxide or oxyhydroxide of at least one metal element, a method for making hydroxide or oxyhydroxide powders therefrom, and the use of the aqueous slurry or hydroxide or oxyhydroxide powders to make cathode active materials for secondary batteries. [Background technology]

[0002] Lithium-ion secondary batteries typically include a negative electrode (anode), an electrolyte, and a positive electrode (cathode) containing a lithium transition metal oxide as an active material capable of intercalating and deintercalating lithium. Generally, lithium transition metal oxides are prepared from transition metal hydroxides, oxides, or oxyhydroxides by a co-precipitation process, which involves mixing a metal salt solution with an alkaline solution in the presence of a complexing agent.

[0003] Automotive applications are expected to become increasingly mainstream in the lithium-ion battery market in the future. To be competitive, batteries for automotive applications must be manufactured at the lowest possible cost. The majority of the cost comes from the active materials, and the cost of precursors is reflected in the cost of the active materials. Providing these precursors through more efficient and / or cheaper processes, ideally without compromising their quality, can help reduce costs and promote market acceptance of lithium-ion secondary batteries.

[0004] In view of the above, there is a constant need for further improvements in the precursor manufacturing process. Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention aims to provide an improved method for making materials that can then be used directly / indirectly as precursors to lithium transition metal cathode materials for positive electrodes. [Means for solving the problem]

[0006] Viewed from a first aspect, the present invention can provide a method for producing an aqueous slurry containing hydroxide or oxyhydroxide particles of one or more elements, where the one or more elements include at least one of Ni, Co, and Mn. The hydroxide or oxyhydroxide particles can be used as a source of seed particles in a precipitation process of a second hydroxide or oxyhydroxide, which can ultimately be used as a lithium transition metal cathode material for a positive electrode or a precursor to a lithium transition metal cathode active material for a positive electrode. Such a method according to the present invention includes: Providing a volume of seed slurry V(1) in a reactor vessel having an effective volume V(2), the seed slurry including seeds having a median particle size d50=D1, the seed slurry having seeds SG(1) having a solids content expressed as weight of seeds per volume of seed slurry; and then providing a stream of an aqueous metal salt solution containing the one or more elements to a reaction vessel for a period of time; during said period, mixing said aqueous metal salt solution with an aqueous solution containing one or more alkali hydroxides, thereby precipitating said hydroxides or oxyhydroxides of said one or more elements to form said aqueous slurry containing particles of said hydroxides or oxyhydroxides of said one or more elements; Including, The step of providing the amount of the seed slurry comprises reacting the amount of the seed slurry with the amount of the seed slurry in accordance with Equation 1:

[0007]

number

[0008] The hydroxide or oxyhydroxide particles of one or more elements according to the present invention have a composition that can be represented by the following general formula: Me-O x (OH) 2-x , where 0≦X≦2, and Me includes at least one of Ni, Co, and Mn, and may optionally include at least one other element such as an impurity such as Na or S.

[0009] The effective volume of the reaction vessel herein refers to the maximum volume of reaction mixture, i.e., aqueous slurry, that can be charged into the reaction vessel during the precipitation reaction / process.

[0010] A period may be shown as T1-T2, which refers to the progression of time, beginning at time T1 (ie, the beginning of the period) and ending at time T2 (ie, the end of the period).

[0011] According to the method of the present invention, the process is better controlled and predictable, and can be easily adjusted according to actual needs, for example, the desired median particle size of hydroxide or oxyhydroxide particles. Also, according to the method, further nucleation is avoided. Further nucleation is undesirable because it may lead to the formation of small particles that tend to agglomerate, which results in changes in production quality. Furthermore, the hydroxide or oxyhydroxide particles produced by the method have a uniformly distributed desired particle size.

[0012] Furthermore, the present invention allows the same seed slurry source to be used regardless of the desired target median size of the precipitated hydroxide or oxyhydroxide particles. This further allows for better control and scalability of the precipitation process compared to known methods, which may require various trial and error efforts to achieve a working process of hydroxide or oxyhydroxide particles of the desired size. An additional advantage over known methods is that it improves the efficiency per reactor of a plant producing metal hydroxides for cathode active materials, since splitting the reaction mixture into various reactors is not necessary to achieve particles of the desired size within a reasonable time.

[0013] Thus, the present invention provides an improved method for the precipitation process of metal hydroxides used as precursors of cathode active materials. The precipitation process may typically involve feeding an aqueous metal salt solution, a neutralizing agent such as an alkali hydroxide, and a complexing agent such as an ammonium ion donor to a reaction vessel with stirring, and carrying out a crystallization reaction.

[0014] Following the concept of the first aspect of the present invention, there is also provided a second aspect of the present invention, which is a method for producing hydroxide or oxyhydroxide powder of one or more elements, the method comprising the steps of: I) providing an aqueous slurry according to the first aspect of the present invention; II) separating the hydroxide or oxyhydroxide particles from a liquid fraction of the aqueous slurry; and III) drying the separated hydroxide or oxyhydroxide particles.

[0015] There is further provided a third aspect of the present invention, which is the use of an aqueous slurry according to the first aspect of the present invention, or a hydroxide or oxyhydroxide powder according to the second aspect of the present invention, for producing a positive electrode active material for a secondary battery.

[0016] There is further provided a fourth aspect of the present invention, which is a method for producing a cathode active material using hydroxide or oxyhydroxide particles produced according to the first and second aspects of the present invention.

[0017] Various embodiments according to the present invention are disclosed in the claims and in this specification. The embodiments and examples described in the claims and this specification are mutually combinable unless expressly stated otherwise. Throughout this specification, when any numerical range is provided, the range also includes the endpoints unless expressly stated otherwise.

[0018] For reference, figures are attached to provide a better understanding of the teachings of the present invention. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 shows scanning electron microscope (SEM) images of the particles obtained from Example 1 and Example 1.2. DETAILED DESCRIPTION OF THE INVENTION

[0020] In the following detailed description, preferred embodiments are described in detail to enable the practice of the invention. Although the invention is described with reference to these specific preferred embodiments, it will be understood that the invention is not limited to these preferred embodiments. On the contrary, the invention includes numerous alternatives, modifications, and equivalents that will become apparent in light of the following detailed description and the accompanying drawings.

[0021] When used in the present specification and claims, the term "comprising" should not be interpreted as being limited to the means listed thereafter, nor does it exclude other elements or steps. It should be interpreted as specifying the presence of the stated structures, integers, steps, or components referred to, but does not preclude the presence or addition of one or more other structures, integers, steps, or components, or groups thereof. Thus, the scope of the expression "a composition comprising components A and B" is not limited to a composition consisting only of components A and B. This means that, in the context of the present invention, the only components relevant to the composition are A and B. Thus, the terms "comprising" and "including" encompass the more restrictive terms "consisting essentially of" and "comprising."

[0022] The term "positive electrode active material" (also known as cathode active material) as used herein and in the claims is defined as a material that is electrochemically active within a positive electrode or cathode. An active material should be understood to be a material that can capture and release Li-ions when subjected to a voltage change over a period of time.

[0023] As used in this disclosure, the term "cathode" is defined as a material that includes a cathode active material in addition to other components that are not electrochemically active, particularly a conductive agent such as carbon black or a binder such as PVDF.

[0024] As used in this disclosure, "NH 3(aq) "Concentration of" and like terms refer to the concentration of ammonia in an aqueous solution.

[0025] In a first aspect, the present invention provides a method for producing an aqueous slurry comprising hydroxide or oxyhydroxide particles of one or more elements, the one or more elements comprising at least one of Ni, Co, and Mn. The hydroxide or oxyhydroxide particles may be used as a source of seed particles in a second hydroxide or oxyhydroxide precipitation process, which may ultimately serve as a precursor to a lithium transition metal cathode material for a positive electrode, or may be used as a precursor to a lithium transition metal cathode active material for a positive electrode. Such a method according to the present invention includes providing a volume of seed slurry V(1) in a reaction vessel having an effective volume V(2), the seed slurry comprising seeds having a median particle size d50=D1, the seed slurry having a solids content of seeds SG(1), expressed as the weight of seeds per volume of seed slurry; and then: During a period of time T1-T2, supplying a stream of an aqueous metal salt solution containing the one or more elements to the reaction vessel; during the period T1-T2, mixing the aqueous metal salt solution with an aqueous solution containing one or more alkali hydroxides, thereby precipitating the hydroxides of the one or more elements and forming the aqueous slurry containing particles of the hydroxide or oxyhydroxide of the one or more elements; Including, providing the amount of seed slurry according to Equation 1:

[0026]

number

[0027] According to the method of the present invention, the precipitation process is better controlled and easier to scale, more predictable, and can be easily adjusted according to actual needs.

[0028] During the course of the manufacturing process, the precipitated hydroxides may be partially oxidized depending on the manufacturing process atmosphere. Therefore, the aqueous slurry may contain oxyhydroxides. Note that atmospheric conditions are not necessary to achieve the claimed invention.

[0029] In some embodiments, the pH of the aqueous slurry in the reaction vessel ranges from 11.5 to 12.2, more preferably from 11.6 to 12.1, as measured on a sample of the aqueous slurry at 20°C. In some embodiments, the pH is within the range of 10.5 to 12.0, preferably from 11.0 to 12.0, which can prevent the nucleation process of new nuclei while ensuring the growth of existing precipitate particles in the reaction vessel. As will be understood by those skilled in the art, the pH can be measured using a pH meter, such as a 780 Metrohm meter.

[0030] In some embodiments of the method according to the present invention, NH 3 is added to the reaction vessel during the period T1-T2. 3(aq) The term "establishing or maintaining" further includes establishing or maintaining a concentration of at least 1.0 g / L, preferably up to 13.0 g / L. 3(aq) ) may be provided in the reaction vessel as a starting solution before the start of the period T1, and additionally or alternatively, an aqueous ammonia solution (NH 3(aq) ) may be supplied to the reaction vessel during the period T1-T2. 3(aq) A concentration lower than 1.0 g / l may result in nucleation. If the particle size of the precipitated hydroxide in the reactor is relatively small, e.g., less than 4 μm or less than 3 μm, a higher NH 3(aq) If the concentration is higher than, for example, 13.0 g / l, it may result in aggregation, and therefore, under these circumstances, NH 3(aq)The concentration of NH is preferably at least 1.5 g / L and up to 7 g / L, more preferably at least 1.5 g / L and up to 6 g / L, and most preferably at least 2 g / L and up to 4 g / L. On the other hand, if the particle size of the precipitated hydroxide in the reactor is relatively large, for example, 4 μm or more, NH 3(aq) The concentration of NH may be controlled to be at the higher end of the range of 1.0 g / L to 13.0 g / L. To allow for slower growth in particle size (i.e., slower precipitation) leading to a denser structure of particles, e.g., NH 3(aq) The concentration of NH(aq) may be at least 7 g / L and up to 13.0 g / L, preferably at least 10 g / L and up to 12.0 g / L. As will be appreciated by those skilled in the art, NH(aq) concentration can be measured by using commercially available titration equipment, for example, a Metrom 848 Titrino Plus.

[0031] In some embodiments of the method according to the present invention, during the period T1-T2, the aqueous slurry in the reaction vessel has a temperature of at least 45°C, preferably at least 75°C, and more preferably at least 85°C. Temperatures below 45°C may increase the porosity of the precipitated hydroxide structure. In some embodiments, the temperature is up to 99°C, preferably up to 95°C, and more preferably up to 90°C. Temperatures above 95°C may result in greater processability difficulties. When the temperature is at least 75°C, preferably at least 80°C or 80°C, and more preferably at least 85°C or 85°C, undesirable cracking of the hydroxide or oxyhydroxide particles can be prevented.

[0032] In some embodiments of the method according to the present invention, the aqueous slurry comprising hydroxide or oxyhydroxide particles of one or more elements has a liquid fraction and a solid fraction, and a portion of the liquid fraction is removed from the reaction vessel during that period, and the solid fraction is retained in the reaction vessel for a period T1-T2.

[0033] Narrow size distribution refers to the span value of the hydroxide or oxyhydroxide, expressed as (D90-D10) / D50, which is typically in the range of <0.8.

[0034] The means for removing a portion of the liquid fraction (i.e., mother liquor) of the aqueous slurry is not particularly limited. However, for example, the removal of a portion of the liquid fraction may be carried out by using a commercially available concentrator, which can selectively remove the liquid fraction from the reaction vessel and may be connected to the reaction vessel.

[0035] In some embodiments, after the end of the period (T2), the aqueous slurry containing hydroxide or oxyhydroxide particles of one or more elements in the reaction vessel has a solids content of at least 600 g / L, preferably at least 750 g / L, of hydroxide or oxyhydroxide particles of one or more elements, preferably the solids content is the target solids content SG(2). By selecting an optimal maximum target solids content, it may be possible to optimize the reaction throughput. As will be appreciated by those skilled in the art, the target solids content may be selected to take into account limitations imposed by the reactor and mixing setup used.

[0036] In some embodiments of the method according to the invention, the mixing comprises mixing 1 ml of the aqueous slurry. 3 Maximum 40 kW per m3 of aqueous slurry, preferably 3 The maximum mixing power required is 35 kW per 1 m. 3 At stirring power requirements of more than 40 kW per m of aqueous slurry, the hydroxide or oxyhydroxide particles may break down into smaller pieces. 3 At least 5 kW per m of aqueous slurry, preferably 3 The stirring power requirements disclosed contribute to obtaining a homogeneous reaction mixture and to avoiding particle agglomeration.

[0037] In some embodiments, the seed median particle size d50, D1, ranges from at least 0.7 μm to a maximum of 2.5 μm, and the target median particle size D50, D2, ranges from at least 3.0 μm to a maximum of 20 μm, preferably D2 is a maximum of 10 μm, and more preferably D2 is a maximum of 7 μm.

[0038] In some embodiments, the seed median particle size d50, D1, ranges from at least 3.0 μm to a maximum of 5 μm, and the target median particle size D50, D2, ranges from at least 5.5 μm to a maximum of 20 μm, preferably D2 is a maximum of 15 μm, and more preferably D2 is a maximum of 13 μm.

[0039] These disclosed seed median particle sizes and target median particle sizes contribute to obtaining excellent sphericity of the precipitated hydroxide or oxyhydroxide particles, maximizing reaction throughput.

[0040] In some embodiments of the method according to the present invention, the seeds are particles of hydroxide or oxyhydroxide of at least one metal element, preferably, said at least one metal element comprises at least Ni. According to the present invention, the metal element for the seed particles and the metal element for the hydroxide or oxyhydroxide particles may be different, which provides further flexibility for carrying out the method according to the present invention.

[0041] In some embodiments of the method according to the present invention, the one or more elements in the hydroxide or oxyhydroxide particles are Ni with a content x, where 5.0 mol%≦x≦99 mol%; Co with a content y of 0≦y≦30.0 mol%; Mn with a content z in which 0≦z≦85.0 mol%; Al with a content q of 0≦q≦10.0 mol%, one or more additional elements with a content r where 0≦r≦5.0 mol%, the additional elements being elements from the list B, Ba, Ca, Cr, Fe, Mg, Mo, Nb, Si, Sr, Ti, Y, V, W, Zn, Na, S, and Zr; and Including, x, y, z, q, and r are the contents, expressed in mol%, of one or more elements in the hydroxide or oxyhydroxide particles relative to the total molar content, where x + y + z + q + r = 100 mol%, preferably x ≥ 60.0 mol%, z ≤ 30.0 mol%, and (y + z) ≥ 1.0 mol%, more preferably x ≥ 70.0 mol%, preferably x ≥ 80.0 mol%, or z ≥ 50.0 mol%, preferably r ≤ 3.0 mol%, and / or z ≥ 60.0 mol%, and / or z ≤ 90.0 mol%, preferably z ≤ 85.0 mol%. The values ​​x, y, z, q, and r are measured by inductively coupled plasma (ICP) techniques. It is understood that the formula ≥ 0 also includes the absence of an element.

[0042] According to the present invention, there is also provided a method for producing hydroxide or oxyhydroxide powder of one or more elements, the method comprising the steps of: I) providing an aqueous slurry according to the method of the present invention described above; II) separating the hydroxide or oxyhydroxide particles from the liquid fraction of the aqueous slurry; and III) drying the separated hydroxide or oxyhydroxide particles.

[0043] During the manufacturing process, the hydroxide or oxyhydroxide particles from the aqueous slurry may be further partially oxidized.

[0044] For example, a precursor containing Ni, Co, and Mn in a molar ratio of x:y:z can be prepared in a mixed form by a precipitation reaction using the following steps: (1) preparing a seed slurry (which may be performed by continuous precipitation), followed by batch precipitation of the mixed hydroxide in a reactor with NaOH and mixed metal salts under a controlled pH as described; (2) removing the precursor suspension and filtering; and (3) drying the filtered wet cake. In step (1), the mixed salts may be mixed sulfates, and the pH may typically be 11-12. Effective precursor drying is typically performed above 100°C for a specific time to remove most of the moisture. The typical water content after drying is less than 1 wt%, which can be measured by the well-known Karl Fischer titration method (ASTM D6869) at 250°C. Before drying, the precursor has a pure or ideal hydroxide crystal structure (with space groups P-3m1).

[0045] In the method according to the invention, the drying of the hydroxide precursor can be carefully carried out under well-defined conditions such as temperature, gas atmosphere and time, which are conditions that can interact such that, for example, a higher drying temperature means that less time is required to obtain the desired product, especially on a mass production scale.

[0046] The dry hydroxide or oxyhydroxide particles according to the present invention, i.e., hydroxide or oxyhydroxide powder, can be used to prepare a positive electrode active material. The hydroxide or oxyhydroxide powder may be mixed with a lithium source to obtain a mixture. The mixture is sintered at a temperature of 650°C to 1000°C. Optionally, a heat treatment at a temperature of 105°C to 750°C may be performed before mixing.

[0047] The present invention therefore also relates to the use of an aqueous slurry comprising hydroxide or oxyhydroxide particles obtainable by the method according to the first aspect of the present invention, and to the use of a hydroxide or oxyhydroxide powder obtainable by the second aspect of the present invention for the manufacture of a positive electrode active material for a secondary battery. [Example]

[0048] pH analysis The pH values ​​of the samples were measured by a 780 Metrohm meter calibrated with standards pH 7 and pH 13. The pH was measured from the samples by cooling them to 20°C, lowering a pH electrode into the sample, and waiting until the pH reading was uniform. NH 3(aq) Concentration analysis NH 3(aq) Concentrations were measured from reactor samples by endpoint titration using a Metrom 848 Titrino Plus instrument. One milliliter of sample solution was added to the titration vessel. 30-40 ml of deionized water and 1 ml of 1 M NaOH were added. The sample was titrated to the endpoint with 0.1 M HCl.

[0049] Solids content analysis To measure the solids content of the precipitated hydroxide in the aqueous slurry, a sample taken from the aqueous slurry (reaction mixture in the examples) was mixed thoroughly, and 10-30 ml of the mixed sample was pipetted onto a filter paper, which was then washed and further filtered on a weighed 0.8 μm membrane. The filtered membrane was rinsed with DI water and then dried, and the weight of the dried membrane was measured, from which the solids content, expressed as the weight of dry hydroxide per liter of aqueous slurry in g / L, was calculated.

[0050] Particle Size Distribution (PSD) Analysis PSD was measured using a Malvern Mastersizer 3000 with a Hydro MV wetting and dispersion unit after dispersing sample particles in aqueous media. Sufficient ultrasonic irradiation and agitation were applied to improve dispersion of the metal hydroxide powder, and appropriate surfactants were added. The percentile values ​​D10, D50, and D90 are the particle diameter values ​​at 10%, 50%, and 90%, respectively, of the cumulative distribution. The span value for hydroxide is (D90-D10) / D50.

[0051] Example 1 Example 1.1 An initiating solution was prepared by charging 6 L of DI water, 55 mL of 220 g / L NH3(aq), and 1.56 L of a 130 g / L seed slurry containing NiOH2 seeds with a D50 of 1.2 μm into a reaction vessel with a working volume of 8.75 L, adjusting the temperature inside the reaction vessel to 85°C, and maintaining this temperature throughout the process. The volume of the seed slurry was calculated using Equation 1 below. The target solids content was 800 g / L, and the target median particle size D50 was 3.9 μm.

[0052] Formula 1:

number

[0053] Next, 120 g / L of a metal sulfate solution containing Ni, Mn, and Co (stoichiometric molar ratio of Ni:Mn:Co=65:15:20), 220 g / L of NH3(aq), and 230 g / L of NaOH solution were added, and the reaction temperature was approximately 30 kW / m for the first 30 hours. 3 The stirring power requirement is about 20 kW / m for the rest of the process. 3 The precipitation reaction was carried out while mixing at a required stirring power of 10 ... 3(aq)The feed rate of 1000 g / L was adjusted. Reactor samples of the reaction mixture were taken every 2 hours, and the D50 was measured therefrom. The process was stopped when the D50 of the reactor sample reached the target value of 3.9 μm. The duration of the process was 36 hours. A portion of the liquid fraction of the reaction mixture was pumped out of the reactor during the process by using a concentrator. The solids content of the reaction mixture, which was an aqueous slurry containing hydroxide particles in the reaction vessel, was approximately the target solids content of 800 g / L at the end of the process.

[0054] The reaction mixture from Example 1.1 can be carried to dryness or can serve as a seed source for further precipitation, for example as described in Example 1.2.

[0055] Example 1.2 The starting solution was prepared by dissolving 6 L of DI water, 350 mL of 220 g / L NH3(aq), and Ni with a D50 of 4.0 μm in a reaction vessel with a working volume of 8.75 L. 65 Mn 15 Co 20 The seed slurry was prepared by charging 515 mL of an 800 g / L seed slurry containing (OH)2 seed particles, adjusting the temperature in the reactor to 85°C, and maintaining this temperature throughout the process. The volume of the seed slurry was calculated using Equation 1 above. The target solids content was 780 g / L, and the target median particle size D50 was 10.2 μm.

[0056] Next, 120 g / L of a metal sulfate solution containing Ni, Mn, and Co (stoichiometric molar ratio of Ni:Mn:Co=65:15:20), 220 g / L of NH3(aq), and 230 g / L of NaOH solution were added, and the reaction was continued for the first 6 hours at approximately 30 kW / m 3 The stirring power requirement is about 20 kW / m for the rest of the process. 3 The precipitation reaction was carried out with stirring at a required stirring power of 0.4 μm / h. The feed rate of the metal sulfate solution was 600 mL / h at the beginning and was continuously increased according to the following equation 2 to reach 3700 mL / h at the end of the process in order to maintain a constant particle growth rate of 0.4 μm / h.

[0057] Formula 2:

number

[0058] where m1 is the mass (grams) of seed particles provided in the reaction vessel, G(t) is the growth rate of hydroxide particles at instant t, where the value of G(t) is not zero, Δt is the period T1-T2, D'50 is the median particle size of the seed particles in μm, and M Me is the molar mass of the one or more elements (grams / mol), and c Me is the concentration of the one or more elements (grams / L), and M Me(OH)2 is the molecular weight (grams / mol) of the hydroxide of one or more elements.

[0059] During the reaction, the supply rate of the NaOH solution was adjusted to stably maintain the pH value of the reaction mixture in the reaction vessel at 11.8±0.1, and the NH 3(aq) The feed rate of NH3(aq) was adjusted to maintain a stable NH3(aq) concentration in the reaction mixture at 12.0±1 g / L. Reactor samples of the reaction mixture were taken every 2 hours, and the D50 was measured therefrom. The process was stopped when the D50 of the reactor sample reached the target value of approximately 10.2 μm. The duration of the process was 15 hours. A portion of the liquid fraction of the reaction mixture was pumped out of the reactor during the process by using a concentrator. The solids content of the reaction mixture, which was an aqueous slurry containing hydroxide particles in the reaction vessel, was approximately 780 g / L of the target solids content at the end of the process.

[0060] Example 2 Example 2.1 The starting solution was prepared by charging 6 L of DI water, 55 mL of 220 g / L NH3(aq), and 410 mL of a 130 g / L aqueous slurry containing NiOH2 seed particles with a D50 of 1.2 μm into a reaction vessel with a working volume of 8.75 L, adjusting the temperature in the reactor to 85°C, and maintaining this temperature throughout the process. The volume of the seed slurry was calculated using Equation 1 above. The target solids content was 440 g / L, and the target median particle size D50 was 5.0 μm.

[0061] Next, 120 g / L of a metal sulfate solution containing Ni, Mn, and Co (stoichiometric molar ratio of Ni:Mn:Co=94:03:03), 220 g / L of NH3(aq), and 230 g / L of NaOH solution were added, and the reaction temperature was approximately 33 kW / m for the first 30 hours. 3 The stirring power requirement is approximately 30 kW / m for the remainder of the process. 3 The precipitation reaction was carried out while mixing at a required stirring power of 10 ... 3(aq) The feed rate of the reaction mixture was adjusted. Reactor samples of the reaction mixture were taken every 2 hours, and the D50 was measured therefrom. The process was stopped when the D50 of the reactor sample reached the target value of 5.0 μm. The duration of the process was 48 hours. A portion of the liquid fraction of the reaction mixture was pumped out of the reactor during the process. The solids content of the reaction mixture, which was an aqueous slurry containing hydroxide particles in the reaction vessel, was approximately the target solids content of 440 g / L at the end of the process.

[0062] The reaction mixture from Example 2.1 can be carried to dryness or can serve as a seed source for further precipitation, for example as described in Example 2.2.

[0063] Example 2.2 The starting solution was prepared by dissolving 6 L of DI water, 350 mL of 220 g / L NH3(aq), and Ni with a D50 of 5.0 μm in a reaction vessel with a working volume of 8.75 L. 94 The seed slurry was prepared by charging 447 mL of a 440 g / L aqueous slurry containing MnO3CoO3(OH)2 seed particles, adjusting the temperature in the reactor to 85°C, and maintaining this temperature throughout the process. The volume of the seed slurry was calculated using Equation 1 above. The target solids content was 180 g / L, and the target median particle size, D50, was 10.0 μm.

[0064] Next, 120 g / L of a metal sulfate solution containing Ni, Mn, and Co (stoichiometric molar ratio of Ni:Mn:Co=94:03:03), 220 g / L of NH3(aq), and 230 g / L of NaOH solution were added, and the reaction was continued for the first 6 hours at approximately 30 kW / m 3 The stirring power requirement is about 20 kW / m for the rest of the process. 3 The precipitation reaction was carried out while mixing at a required stirring power of 10 ... 3(aq) The feed rate of 10.0 g / L was adjusted. Reactor samples of the reaction mixture were taken every 2 hours and the D50 was measured therefrom. The process was stopped when the D50 of the reactor sample reached the target value of approximately 10.0 μm. The duration of the process was 11 hours. A portion of the liquid fraction of the reaction mixture was pumped out of the reactor during the process. The solids content of the reaction mixture in the reaction vessel was the target solids content of approximately 180 g / L at the end of the process.

Claims

1. 1. A method for producing an aqueous slurry containing particles of hydroxides or oxyhydroxides of one or more elements, comprising: the one or more elements include at least one of Ni, Co, and Mn; The method comprises: providing a seed slurry of a volume V(1) into a reactor vessel having an effective volume V(2), the seed slurry having a median particle size d50=D １ providing a seed slurry comprising seeds having a solids content SG(1) expressed as weight of seeds per volume of the seed slurry; after that, - during a period (T1-T2) supplying a flow of aqueous metal salt solution containing said one or more elements to said reaction vessel; - during said period (T1-T2), mixing said aqueous metal salt solution with an aqueous solution containing one or more alkali hydroxides, thereby forming said aqueous slurry containing particles of said hydroxide or oxyhydroxide of said one or more elements; Including, The seed slurry is fed according to Equation 1: [Equation 1] where SG(2) is the target solids content of the aqueous slurry expressed as weight of hydroxide or oxyhydroxide particles per volume of aqueous slurry, and D ２ is the target median particle size D50 of the hydroxide or oxyhydroxide particles expressed in μm.

2. 2. The method of claim 1, wherein the pH value of the aqueous slurry in the reaction vessel ranges from 11.5 to 12.2, more preferably from 11.6 to 12.1, wherein the pH of the aqueous slurry is the pH measured on a sample of the aqueous slurry at 20°C.

3. Aqueous solution of ammonia (i.e., aqueous ammonia (NH ３（ａｑ） ) into the reaction vessel, and ３（ａｑ） 3. The method according to claim 1, wherein the concentration of is at least 1.0 g / l and preferably up to 13.0 g / l.

4. 4. The method according to any one of claims 1 to 3, wherein during said period (T1-T2), the aqueous slurry comprising the hydroxide or oxyhydroxide particles of the one or more elements in the reaction vessel has a temperature of at least 45°C, preferably at least 75°C, more preferably at least 85°C or higher, and up to 99°C, preferably up to 95°C, more preferably up to 90°C.

5. 5. The method of claim 1, wherein the aqueous slurry containing the hydroxide or oxyhydroxide particles of the one or more elements has a liquid fraction and a solid fraction, and a portion of the liquid fraction is removed from the reaction vessel during the period (T1 to T2), and the solid fraction is retained in the reaction vessel during the period (T1 to T2).

6. 6. The method according to any one of claims 1 to 5, wherein, after the end of the period (T2), the aqueous slurry comprising the hydroxide or oxyhydroxide particles of the one or more elements in the reaction vessel has a solids content of the hydroxide or oxyhydroxide particles of the one or more elements of at least 600 g / l, preferably at least 750 g / l, preferably at the target solids content SG(2).

7. The mixing is carried out by adding 1 m ３ Up to 40 kW per m of said aqueous solution, preferably ３ 7. The method according to claim 1, wherein the method is carried out at a stirring power requirement of up to 35 kW per minute.

8. The median particle size d50 of the seeds is D １ is in the range of at least 0.7 μm to a maximum of 2.5 μm; The target particle size median D50 is D ２ is at least 3.0 μm and up to 20 μm, and preferably D ２ is up to 10 μm, and more preferably, D ２ The method according to any one of claims 1 to 7, wherein the thickness is up to 7 µm.

9. The median particle size d50 of the seeds is D １ is in the range of at least 3.0 μm to a maximum of 5 μm; The target particle size median D50 is D ２ is at least 5.5 μm and up to 20 μm, and preferably D ２ is up to 15 μm, and more preferably, D ２ The method according to any one of claims 1 to 7, wherein the thickness of the film is up to 13 µm.

10. The method according to any one of claims 1 to 9, wherein the seeds are particles of hydroxide or oxyhydroxide of at least one metallic element, preferably the at least one metallic element comprises at least Ni.

11. The one or more elements in the hydroxide or oxyhydroxide particles are Ni with a content x, where 5.0 mol%≦x≦99 mol%; Co with a content y of 0≦y≦30.0 mol%; Mn with a content z in the range of 0≦z≦85.0 mol%, , Al with a content q of 0≦q≦10.0 mol%; one or more additional elements with a content r where 0≦r≦5.0 mol%, said additional elements being from the list B, Ba, Ca, Ce, Cr, Fe, La, Mg, Mo, Nb, Si, Sr, Ti, Y, V, W, Zn, Na, S and Zr; Including, 11. The method according to any one of claims 1 to 10, wherein x, y, z, q, and r are contents expressed in mol % relative to the total molar content of one or more elements in the hydroxide or oxyhydroxide particles, such that x+y+z+q+r=100 mol %.

12. 1. A method for producing a hydroxide or oxyhydroxide powder of one or more elements, comprising: I) carrying out a method for producing an aqueous slurry comprising particles of hydroxides or oxyhydroxides of one or more elements according to any one of claims 1 to 11; II) separating the hydroxide or oxyhydroxide particles from the liquid fraction of the aqueous slurry; III) drying the separated hydroxide or oxyhydroxide particles; A method comprising:

13. A method for producing a positive electrode active material, comprising: 1) producing a powder of hydroxide or oxyhydroxide of one or more elements by the method of claim 12; 2) mixing the hydroxide or oxyhydroxide powder with a lithium source to obtain a mixture; 3) sintering the mixture at a temperature between 650°C and 1000°C; A method comprising:

14. Use of an aqueous slurry containing particles of hydroxides or oxyhydroxides of one or more elements obtained by the method according to any one of claims 1 to 11, or a powder of hydroxides or oxyhydroxides of one or more metal elements obtained by the method according to claim 12, for producing a positive electrode active material for a secondary battery.

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