Wide distribution large particle high nickel ternary precursor, preparation method and application thereof

Abstract

This invention relates to a wide-distribution, large-particle, high-nickel ternary precursor, its preparation method, and its application. The preparation method includes: adding a precipitant solution, a complexing agent solution, a dispersant, a seed slurry, and a growth substrate to a reaction vessel; adding a nickel-cobalt-manganese ternary salt mixture, the precipitant solution, and the complexing agent solution concurrently to the resulting reaction substrate for a first co-precipitation; after reaching a first particle size, adding the seed slurry for a second co-precipitation; after reaching a second particle size, adjusting the hourly feed volume of the seed slurry and connecting it to an overflow container to continue the second co-precipitation until a third particle size is reached and maintained; stopping the reaction when the maximum particle size reaches the cutoff particle size, and aging to obtain the wide-distribution, large-particle, high-nickel ternary precursor. This invention achieves wide particle size distribution control of the large-particle, high-nickel ternary precursor through dynamic feeding of the seed slurry, while also enabling continuous feeding and discharging, reducing material waste in intermittent processes and increasing the yield of precursors per batch.

Description

Technical Field

[0001] This invention relates to the field of precursor preparation technology for new energy battery materials, and in particular to a wide-distribution, large-particle, high-nickel ternary precursor, its preparation method, and its application. Background Technology

[0002] Lithium-ion batteries are widely used in various electronic fields due to their advantages such as high energy density, long cycle life, high output voltage, and zero pollution. As a crucial component of lithium-ion batteries, the performance of the positive electrode active material directly affects the battery's overall performance. With the increasing performance requirements of various electronic devices, the demand for energy density in lithium-ion batteries is also gradually increasing. Therefore, improving the capacity per unit volume of battery is currently a key research focus and a direction for development.

[0003] High-nickel cathode materials possess high energy density; as the nickel content increases, the specific capacity of the material significantly improves (reaching over 200 mAh / g). This allows the battery to store more energy within the same volume and weight, thereby increasing the battery's energy density and meeting the demands for long driving range in fields such as electric vehicles. However, compared to traditional cathode materials, high-nickel cathode materials are more prone to cracking or decomposition during the preparation, rolling, or cycling processes, and it is difficult to simultaneously achieve high sphericity and tap density.

[0004] Studies have shown that high-nickel ternary precursor materials with wide particle size distribution have advantages such as high compaction density, high tap density, and high volumetric energy density, leading to their widespread market application. Currently, the mainstream preparation method for high-nickel ternary precursors is the co-precipitation method, which uses nickel-cobalt-manganese metal salt solutions as raw materials, adds precipitants and complexing agents, and the three react in a reactor to obtain the final product.

[0005] CN115072794A discloses a method for preparing a ternary precursor with controllable particle size distribution. The method first prepares seed crystals, and then performs subsequent growth. By continuously adding seed crystals, the particle size distribution width of the product can be controlled. The specific process includes: adding seed crystal material to the growth vessel at a constant rate using a continuous feeding method; adding a mixed metal salt solution, sodium hydroxide solution, and ammonia water to the growth vessel in a parallel flow to carry out the reaction; controlling the reaction temperature, pH, and ammonia concentration; stopping the feeding when the D50 of the material in the growth vessel reaches 8.0-20.0 μm and the K90 reaches 0.7-1.6, and continuing to stir and age for 1-2 hours to obtain the desired ternary precursor product.

[0006] CN116216792A discloses a method for preparing a broad-distribution, fine-powder-free, spherical high-nickel ternary precursor material using a seed-controlled precipitation method. The method involves pumping a mixed salt solution, complexing agent solution, precipitant solution, and seed slurry into a reactor in parallel flow under protective gas conditions and with stirring on. Co-precipitation achieves the interaction of NH4-Ni-Co-Mn-OH. Complexation coupling is achieved through the combined effects of stirring, gas disturbance, and liquid flow in a constant temperature and pressure atmosphere. After post-treatment of the slurry at the reaction endpoint, a broad-distribution, fine-powder-free, spherical high-nickel precursor material is obtained.

[0007] As can be seen from the above-mentioned existing technologies, although they can all achieve the preparation of (high-nickel) ternary precursors with a wide particle size distribution, they generally suffer from the problem of low precursor quality per batch, making it impossible to achieve simultaneous feeding and discharging for continuous production. Consequently, if large-scale preparation of precursors is desired, the same process needs to be repeated multiple times (intermittent method), which leads to a large amount of material waste and increased preparation costs. In addition, maintaining a constant ratio of seed crystal to ternary liquid flow rate also makes it impossible to achieve precise control of particle size distribution.

[0008] Therefore, how to effectively increase the quality of high-nickel ternary precursors in single-batch production, achieve simultaneous feeding and discharging, and at the same time ensure precise control to prepare high-nickel ternary precursors with a wide particle size distribution has become an urgent problem to be solved. Summary of the Invention

[0009] To address the aforementioned technical problems, this invention provides a wide-distribution, large-particle, high-nickel ternary precursor, its preparation method, and its applications. This invention achieves precise control of the wide particle size distribution of the large-particle, high-nickel ternary precursor through dynamic feeding control of the seed slurry. Furthermore, by altering the feeding rate (volume per hour) of the seed slurry in the later stages of the reaction, the particle size of the high-nickel ternary precursor is kept constant within a certain range around the average particle size D50 of the target wide-distribution, large-particle, high-nickel ternary precursor during the reaction. This ensures continuous output while feeding, reducing material waste in batch processes and increasing the quality of a single batch of wide-distribution, large-particle, high-nickel ternary precursor.

[0010] To achieve this objective, the present invention adopts the following technical solution:

[0011] In a first aspect, the present invention provides a method for preparing a broadly distributed, large-particle, high-nickel ternary precursor, the method comprising the following steps:

[0012] (1) Add the precipitant solution, complexing agent solution, dispersant, seed slurry and growth base liquid to the reaction vessel for the first mixing to obtain the reaction base liquid. Then add the nickel-cobalt-manganese ternary salt mixture, precipitant solution and complexing agent solution in parallel to the reaction base liquid for the first coprecipitation reaction.

[0013] (2) After reaching the first particle size D501, seed slurry is added, and the nickel-cobalt-manganese ternary salt mixture, the precipitant solution and the complexing agent solution in step (1) are added in parallel to carry out the second co-precipitation reaction.

[0014] (3) After reaching the second particle size D502, adjust the hourly feed volume of the seed slurry described in step (2) and connect it to the overflow container to continue the second co-precipitation reaction, so as to reach and maintain the third particle size D503.

[0015] (4) At the maximum particle size D max When the cutoff particle size is reached, the reaction is stopped, and the slurry in the reaction vessel and the overflow vessel is aged to obtain a wide-distribution, large-particle, high-nickel ternary precursor.

[0016] This invention achieves precise control over the wide particle size distribution of large-particle high-nickel ternary precursors through dynamic feeding control of the seed slurry, while also improving the preparation quality of single batches of wide-distribution large-particle high-nickel ternary precursors. In the early stages of the reaction, both the seed slurry and reactants are added at a constant feed rate to promote particle growth and increase particle size. Once the particle size reaches a certain range, the hourly feed volume of the seed slurry is then adjusted in real-time to maintain the particle size consistently within a certain range around the average particle size D50 of the target wide-distribution large-particle high-nickel ternary precursor, preventing a continuous increase in precursor particle size. This ensures continuous feeding and output while simultaneously improving the preparation quality of single batches of wide-distribution large-particle high-nickel ternary precursors. The resulting wide-distribution large-particle high-nickel ternary precursor exhibits high tap density and compaction density, resulting in superior electrochemical performance of the high-nickel cathode material.

[0017] As a preferred technical solution of the present invention, the average particle size of the wide-distribution large-particle high-nickel ternary precursor is denoted as D50, and the first particle size D501 is 45% to 65% of D50, such as 45%, 48%, 50%, 52%, 55%, 58%, 60%, 62% or 65%, etc.

[0018] In this invention, after adjusting the first particle size D501 to 45% to 65% of the D50, the seed slurry is dynamically adjusted. If the first particle size D501 is too small relative to the average particle size D50 of the widely distributed large-particle high-nickel ternary precursor, it will result in a longer time required to reach the target particle size, thus affecting the preparation efficiency. If the first particle size D501 is too large relative to the average particle size D50 of the widely distributed large-particle high-nickel ternary precursor, it will result in more ultra-large particles, fewer medium-sized particles, and discontinuous particle size distribution.

[0019] Preferably, the average particle size of the wide-distribution, large-particle, high-nickel ternary precursor is denoted as D50, and the second particle size D502 is 75% to 95% of D50, such as 75%, 78%, 80%, 82%, 85%, 88%, 90%, 92%, or 95%.

[0020] Preferably, the average particle size of the wide-distribution, large-particle, high-nickel ternary precursor is denoted as D50, and the third particle size D503 is 80% to 120% of D50, such as 80%, 85%, 90%, 95%, 100%, 105%, 110%, 115%, or 120%.

[0021] Preferably, the average particle size of the wide-distribution, large-particle, high-nickel ternary precursor is denoted as D50, and the cutoff particle size is 3 times or more than D50, such as 3 times, 3.5 times, 4 times, 4.5 times, or 5 times.

[0022] In this invention, adjusting the cutoff particle size to 3 times or more of D50 allows sufficient time for overflow of enough product, ensuring maximum production output. If the cutoff particle size is too small, it will result in a short receiving time and a reduced single-batch precursor production output.

[0023] As a preferred technical solution of the present invention, the precipitant solution in step (1) includes any one or a combination of at least two of sodium hydroxide solution, sodium carbonate solution or ammonium carbonate solution.

[0024] Preferably, the mass concentration of the precipitant solution in step (1) is 200 g / L to 500 g / L, such as 200 g / L, 250 g / L, 300 g / L, 350 g / L, 400 g / L, 450 g / L or 500 g / L.

[0025] Preferably, the complexing agent solution in step (1) includes any one or a combination of at least two of ammonia water, oxalic acid solution, citric acid solution or ascorbic acid solution.

[0026] Preferably, the mass concentration of the complexing agent solution in step (1) is 9 mol / L to 15 mol / L, for example, 9 mol / L, 10 mol / L, 11 mol / L, 12 mol / L, 13 mol / L, 14 mol / L or 15 mol / L.

[0027] Preferably, the dispersant in step (1) comprises polyethylene glycol and / or hexadecyltrimethylammonium bromide.

[0028] Preferably, the amount of dispersant added in step (1) is 1 wt% to 10 wt% of the mass of the nickel-cobalt-manganese ternary salt mixture, for example, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, or 10 wt%.

[0029] As a preferred technical solution of the present invention, in the nickel-cobalt-manganese ternary salt mixture in step (1), the molar ratio of Ni:Co:Mn is x:y:z, x+y+z=1, 0.8≤x≤0.97, for example 0.8, 0.82, 0.85, 0.88, 0.9, 0.92, 0.95 or 0.97 etc.

[0030] Preferably, the total mass concentration of metal salts in the nickel-cobalt-manganese ternary salt mixture in step (1) is 80 g / L to 120 g / L, such as 80 g / L, 85 g / L, 90 g / L, 95 g / L, 100 g / L, 105 g / L, 110 g / L, 115 g / L or 120 g / L.

[0031] Preferably, in the nickel-cobalt-manganese ternary salt mixture, the compounds corresponding to the nickel source, cobalt source and manganese source include sulfates and / or nitrates.

[0032] Preferably, the hourly feed volume of the nickel-cobalt-manganese ternary salt mixture in step (1) is 2% to 5% of the volume of the reaction vessel, such as 2%, 2.5%, 3%, 3.5%, 4%, 4.5% or 5%.

[0033] As a preferred embodiment of the present invention, the molar ratio of Ni:Co:Mn in the seed slurry is the same as the molar ratio of Ni:Co:Mn in the nickel-cobalt-manganese ternary salt mixture.

[0034] Preferably, the concentration of the seed slurry is 20 g / L to 100 g / L, such as 20 g / L, 30 g / L, 40 g / L, 50 g / L, 60 g / L, 70 g / L, 80 g / L, 90 g / L, or 100 g / L.

[0035] Preferably, the average particle size of the wide-distribution, large-particle, high-nickel ternary precursor is denoted as D50, and the average particle size D504 of the seed slurry is 25% to 35% of D50, such as 25%, 28%, 30%, 32%, or 35%.

[0036] Preferably, the growth substrate in step (1) includes pure water.

[0037] Preferably, the volume of the growth substrate added in step (1) is 40% to 50% of the volume of the reaction vessel, such as 40%, 42%, 45%, 48% or 50%.

[0038] Preferably, the amount of seed slurry added in step (1) is 0.5wt% to 5wt% of the mass of the growth substrate, such as 0.5wt%, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt%, or 5wt%.

[0039] As a preferred technical solution of the present invention, the temperature of the first mixing in step (1) is 40℃~80℃, for example 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃ or 80℃, etc.

[0040] Preferably, the rotational speed of the first mixing in step (1) is 400 r / min to 700 r / min, for example, 400 r / min, 450 r / min, 500 r / min, 550 r / min, 600 r / min, 650 r / min or 700 r / min.

[0041] Preferably, the pH of the reaction substrate in step (1) is 9 to 12, such as 9, 9.5, 10, 10.5, 11, 11.5 or 12.

[0042] Preferably, when the complexing agent solution is ammonia water, the total ammonia concentration in the reaction substrate in step (1) is 3g / L to 8g / L, for example, 3g / L, 4g / L, 5g / L, 6g / L, 7g / L or 8g / L.

[0043] Preferably, the first coprecipitation reaction in step (1) is carried out under an inert atmosphere.

[0044] Preferably, the inert gas used in the inert atmosphere includes nitrogen and / or argon.

[0045] Preferably, the temperature of the first coprecipitation reaction in step (1) is 40℃~80℃, for example 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃ or 80℃.

[0046] Preferably, the rotation speed of the first coprecipitation reaction in step (1) is 400 r / min to 700 r / min, for example, 400 r / min, 450 r / min, 500 r / min, 550 r / min, 600 r / min, 650 r / min or 700 r / min.

[0047] Preferably, the pH of the first coprecipitation reaction in step (1) is 9 to 12, such as 9, 9.5, 10, 10.5, 11, 11.5 or 12.

[0048] Preferably, when the complexing agent solution is ammonia water, in the first coprecipitation reaction process of step (1), the total ammonia concentration in the reaction mixture is 3g / L to 8g / L, for example, 3g / L, 4g / L, 5g / L, 6g / L, 7g / L or 8g / L.

[0049] As a preferred technical solution of the present invention, the hourly feed volume of the seed slurry in step (2) is 1.2% to 6.5% of the volume of the reaction vessel, for example, 1.2%, 1.5%, 2%, 2.2%, 2.5%, 2.8%, 3%, 3.2%, 3.5%, 3.8%, 4%, 4.2%, 4.5%, 4.8%, 5%, 5.2%, 5.5%, 5.8%, 6%, 6.2%, or 6.5%, etc.

[0050] In this invention, the hourly feed volume of the seed slurry in step (2) is controlled to be 1.2% to 6.5% of the volume of the reaction vessel. If the hourly feed volume is too low, there will be more ultra-large particles and fewer medium particles, resulting in discontinuous particle size distribution. If the hourly feed volume is too high, the seed crystals will lower the average particle size, and the time required to reach the target particle size will be longer, thus affecting the preparation efficiency.

[0051] Preferably, the second coprecipitation reaction is carried out under an inert atmosphere.

[0052] Preferably, the inert gas used in the inert atmosphere includes nitrogen and / or argon.

[0053] Preferably, the temperature of the second coprecipitation reaction is 40℃ to 80℃, for example, 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃ or 80℃.

[0054] Preferably, the rotation speed of the second coprecipitation reaction is 300 r / min to 400 r / min, for example, 300 r / min, 320 r / min, 350 r / min, 380 r / min or 400 r / min.

[0055] Preferably, the pH of the second coprecipitation reaction is 9 to 12, such as 9, 9.5, 10, 10.5, 11, 11.5 or 12.

[0056] Preferably, the internal reaction temperature of the overflow container is 40℃~80℃, for example, 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃ or 80℃.

[0057] Preferably, the interior of the overflow container is inert.

[0058] Preferably, the inert gas used in the inert atmosphere includes nitrogen and / or argon.

[0059] Preferably, the internal reaction speed of the overflow container is 200 r / min to 500 r / min, such as 200 r / min, 250 r / min, 300 r / min, 350 r / min, 400 r / min, 450 r / min or 500 r / min.

[0060] Preferably, the aging temperature in step (4) is 40℃~80℃, for example 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃ or 80℃.

[0061] Preferably, the aging time in step (4) is 6h to 10h, for example, 6h, 7h, 8h, 9h or 10h.

[0062] Preferably, the pH of the aging process in step (4) is 10 to 12, such as 10, 10.2, 10.5, 10.8, 11, 11.2, 11.5, 11.8 or 12.

[0063] Preferably, the aging speed in step (4) is 200 r / min to 500 r / min, for example, 200 r / min, 250 r / min, 300 r / min, 350 r / min, 400 r / min, 450 r / min or 500 r / min.

[0064] Preferably, the concentration of total alkali in the slurry in step (4) is 10 g / L to 40 g / L, for example, 10 g / L, 15 g / L, 20 g / L, 25 g / L, 30 g / L, 35 g / L or 40 g / L.

[0065] Preferably, after the aging process described in step (4) is completed, the process further includes washing and drying in sequence.

[0066] Preferably, the washing includes an alkaline wash and a water wash performed sequentially.

[0067] Preferably, the drying temperature is 80℃~120℃, such as 80℃, 85℃, 90℃, 95℃, 100℃, 105℃, 110℃, 115℃ or 120℃.

[0068] As a preferred technical solution of the present invention, the preparation method includes the following steps:

[0069] (1) A precipitant solution with a mass concentration of 200 g / L to 500 g / L, a complexing agent solution with a mass concentration of 9 mol / L to 5 mol / L, a dispersant, a seed slurry, and a growth substrate are added to a reaction vessel. The mixture is first mixed at 40°C to 80°C and 400 r / min to 700 r / min to obtain a reaction substrate with a pH of 9 to 12. Under an inert atmosphere, a nickel-cobalt-manganese ternary salt mixture, a precipitant solution, and a complexing agent solution are added to the reaction substrate in parallel. The first coprecipitation reaction is carried out at 40°C to 80°C, 400 r / min to 700 r / min, and a pH of 9 to 12. When the complexing agent solution is ammonia, the mass concentration of total ammonia in the reaction mixture during the first coprecipitation reaction is 3 g / L to 8 g / L.

[0070] In the nickel-cobalt-manganese ternary salt mixture, the molar ratio of Ni:Co:Mn is x:y:z, x+y+z=1, and 0.8≤x≤0.97; the total mass concentration of the metal salts in the nickel-cobalt-manganese ternary salt mixture is 80g / L~120g / L; the hourly feed volume of the nickel-cobalt-manganese ternary salt mixture is 2%~5% of the volume of the reaction vessel; the added volume of the growth substrate is 40%~50% of the volume of the reaction vessel; the added amount of the seed slurry is 0.5wt%~5wt% of the mass of the growth substrate; when the complexing agent solution is ammonia water, the total ammonia mass concentration in the reaction substrate is 3g / L~8g / L; and the added amount of the dispersant is 1wt%~10wt% of the mass of the nickel-cobalt-manganese ternary salt mixture.

[0071] (2) After reaching the first particle size D501, maintain an inert atmosphere, add seed slurry, and continue to add the nickel-cobalt-manganese ternary salt mixture, the precipitant solution and the complexing agent solution in step (1) in parallel flow, and carry out the second coprecipitation reaction at 40℃~80℃, 300r / min~400r / min and pH 9~12.

[0072] The molar ratio of Ni:Co:Mn in the seed slurry is the same as that in the nickel-cobalt-manganese ternary salt mixture; the concentration of the seed slurry is 20 g / L to 100 g / L; the average particle size D504 of the seed slurry is 25% to 35% of the average particle size D50 of the widely distributed large-particle high-nickel ternary precursor; and the hourly feed volume of the seed slurry is 1.2% to 6.5% of the volume of the reaction vessel.

[0073] (3) After reaching the second particle size D502, maintain an inert atmosphere, adjust the hourly feed volume of the seed slurry described in step (2), and connect it to the overflow container to continue the second co-precipitation reaction, so as to reach and maintain the third particle size D503.

[0074] (4) At the maximum particle size D max When the cutoff particle size is reached, the reaction is stopped, and the slurry in the reaction vessel and the overflow vessel is aged for 6 to 10 hours at 40℃~80℃, 200r / min~500r / min, pH 10~12, and total alkali concentration of 10g / L~40g / L. After washing and drying at 80℃~120℃, a wide-distribution large-particle high-nickel ternary precursor is obtained.

[0075] The average particle size of the wide-distribution, large-particle, high-nickel ternary precursor is denoted as D50. The first particle size D501 is 45% to 65% of D50, the second particle size D502 is 75% to 95% of D50, the third particle size D503 is 80% to 120% of D50, and the cutoff particle size is 3 times or more of D50.

[0076] In a second aspect, the present invention also provides a wide-distribution large-particle high-nickel ternary precursor prepared according to the preparation method described in the first aspect, wherein the particle size distribution width of the wide-distribution large-particle high-nickel ternary precursor is 0.8 to 2.0, for example, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9 or 2.0.

[0077] In this invention, the particle size distribution width span = (D90 - D10) / D50.

[0078] Preferably, the average particle size D50 of the wide-distribution, large-particle, high-nickel ternary precursor is 7μm to 15μm, such as 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, or 15μm.

[0079] Thirdly, the present invention also provides an application of a wide-distribution, large-particle, high-nickel ternary precursor, wherein the wide-distribution, large-particle, high-nickel ternary precursor prepared by the preparation method described in the first aspect, or the wide-distribution, large-particle, high-nickel ternary precursor described in the second aspect, is applied to battery materials.

[0080] Compared with the prior art, the present invention has at least the following beneficial effects:

[0081] 1) This invention achieves precise control of the wide particle size distribution of large-particle high-nickel ternary precursors through dynamic feeding control of seed slurry. At the same time, it can also increase the preparation quality of wide-distribution large-particle high-nickel ternary precursors in a single batch, while taking into account both preparation efficiency and yield.

[0082] 2) The wide-distribution, large-particle, high-nickel ternary precursor obtained by this invention has a wide particle size distribution, and the precursor D50 is maintained at 7μm to 15μm, achieving a wide distribution control of span value from 0.8 to 2.0. It has high tap density and compaction density, thereby enabling the high-nickel cathode material to have better electrochemical performance. Attached Figure Description

[0083] Figure 1 This is a SEM image of the wide-distribution, large-particle, high-nickel ternary precursor provided in Embodiment 1 of the present invention.

[0084] Figure 2 This is a SEM image of the wide-distribution, large-particle, high-nickel ternary precursor provided in Embodiment 2 of the present invention.

[0085] Figure 3 This is a SEM image of the wide-distribution, large-particle, high-nickel ternary precursor provided in Embodiment 3 of the present invention.

[0086] Figure 4 This is a SEM image of the large-particle high-nickel ternary precursor provided in Comparative Example 1 of this invention. Detailed Implementation

[0087] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, the following examples are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

[0088] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0089] Example 1

[0090] This embodiment provides a method for preparing a broadly distributed, large-particle, high-nickel ternary precursor, the preparation method comprising the following steps:

[0091] (1) The average particle size D50 of the target wide-distribution, large-particle, high-nickel ternary precursor was determined to be 10.5 μm. A nickel-cobalt-manganese ternary salt mixture with a Ni:Co:Mn molar ratio of 0.93:0.05:0.02 was prepared, and the total mass concentration of the three metal salts, nickel sulfate, cobalt sulfate, and manganese sulfate, was 80 g / L. A sodium hydroxide solution with a mass concentration of 400 g / L and an ammonia solution with a mass concentration of 10 mol / L were prepared. A seed slurry with a Ni:Co:Mn molar ratio of 0.93:0.05:0.02 and a concentration of 20 g / L was prepared.

[0092] Sodium hydroxide solution, ammonia, polyethylene glycol and seed slurry were added to the reactor, and 50% pure water (by volume of the reactor) was added as the growth substrate. The mass of the seed slurry was 5 wt% of the mass of the pure water. The first mixing was carried out at 60℃ and 600 r / min to obtain a reaction substrate with a pH of 12 and a total ammonia concentration of 8 g / L.

[0093] Under a nitrogen atmosphere, a nickel-cobalt-manganese ternary salt mixture, sodium hydroxide solution, and ammonia water were added to the reaction base solution in parallel flow. The feed volume of the nickel-cobalt-manganese ternary salt mixture was 3% of the reactor volume per hour. The first coprecipitation reaction was carried out at 60℃, 600r / min, and pH 12. The total ammonia mass concentration in the reaction mixture was 8g / L.

[0094] (2) When the first particle size D501 of the particles in the reactor reaches 45% of the target D50, maintain the nitrogen atmosphere and add a seed slurry with a concentration of 20 g / L, a feed volume of 4% of the reactor volume per hour, and an average particle size D504 of 35% of the target D50 (the same seed slurry as in step (1)). The nickel-cobalt-manganese ternary salt mixture, precipitant solution and complexing agent solution from step (1) are added in parallel. The second coprecipitation reaction is carried out at 60°C, 400 r / min and pH 12.

[0095] (3) When the second particle size D502 of the particles in the reactor reaches 85% of the target D50, maintain the nitrogen atmosphere and dynamically adjust the hourly feed volume of the seed slurry in step (2) so that the particle size of the high nickel ternary precursor in the reactor reaches and is maintained at the third particle size D503, where D503 is 90% to 110% of the target D50. At this time, connect to the overflow vessel to collect the overflow slurry of the reactor. The reaction temperature in the overflow vessel is maintained at 60°C, the rotation speed is 300 r / min, and the interior is in a nitrogen atmosphere. When the overflow slurry is close to 85% of the overflow vessel volume, use a thickener to purify it, discharge part of the mother liquor, and increase the volume that can accommodate the overflow material.

[0096] (4) When the maximum particle size D max The reaction was stopped when the cutoff particle size was reached, which was 3.3 times the target average particle size D50. All slurries in the reactor and overflow vessel were aged for 8 hours at 60℃, pH 12, total alkali concentration of 40 g / L, and rotation speed of 500 r / min. After aging, the slurries were washed with alkali 4 times, washed with water 4 times, and dried at 120℃ to obtain a wide-distribution large-particle high-nickel ternary precursor with an average particle size D50 of 10.5 μm.

[0097] Figure 1 The image shows a SEM image of the wide-distribution, large-particle, high-nickel ternary precursor provided in Embodiment 1 of the present invention. As can be seen from the image, the particle size distribution is wide, with no micro-powder and no cracks.

[0098] The preparation methods of the wide-distribution, large-particle, high-nickel ternary precursors provided in Examples 2-5 are based on the preparation method in Example 1 with parameter changes. The specific parameters changed in Examples 2-5 are shown in Table 1.

[0099] The wide-distribution, large-particle, high-nickel ternary precursors provided in Examples 1-5 were subjected to D90 and D10 tests using a laser diffraction particle size analyzer (Malvin 3000). The particle size distribution width span = (D90-D10) / D50 was calculated, and the specific data are shown in Table 1.

[0100] Figure 2 The image shows an SEM image of the wide-distribution, large-particle, high-nickel ternary precursor provided in Embodiment 2 of the present invention. As can be seen from the image, the particle size distribution is wide, with no micro-powder and no cracks.

[0101] Figure 3 The image shows a SEM image of the wide-distribution, large-particle, high-nickel ternary precursor provided in Embodiment 3 of the present invention. As can be seen from the image, the particle size distribution is wide and there is no micron powder.

[0102] Table 1

[0103]

[0104] Comparative Example 1

[0105] This comparative example provides a method for preparing a large-particle high-nickel ternary precursor, the method comprising the following steps:

[0106] (1) The average particle size D50 of the target large-particle high-nickel ternary precursor was determined to be 10.5 μm. A nickel-cobalt-manganese ternary salt mixture with a Ni:Co:Mn molar ratio of 0.93:0.05:0.02 was prepared, and the total mass concentration of the three metal salts, nickel sulfate, cobalt sulfate and manganese sulfate, was 80 g / L. A sodium hydroxide solution with a mass concentration of 400 g / L and an ammonia solution with a mass concentration of 10 mol / L were also prepared.

[0107] Sodium hydroxide solution, ammonia water and polyethylene glycol were added to the reactor, and 50% of the reactor volume of pure water was added as the growth substrate. The first mixing was carried out at 60℃ and 600r / min to obtain the reaction substrate with a pH of 12 and a total ammonia mass concentration of 8g / L.

[0108] Under a nitrogen atmosphere, a nickel-cobalt-manganese ternary salt mixture, sodium hydroxide solution, and ammonia water were added concurrently to the reaction substrate. The feed volume of the nickel-cobalt-manganese ternary salt mixture was 3% of the reactor volume per hour. A co-precipitation reaction was carried out at 60℃, 600 r / min, and pH 12. The total ammonia concentration in the reaction mixture was 8 g / L. After the reaction, the slurry in the reactor was aged for 8 h at 60℃, pH 12, total alkali concentration of 40 g / L, and rotation speed of 500 r / min. After aging, the slurry was washed with alkali 4 times, washed with water 4 times, and dried at 120℃ to obtain a large-particle high-nickel ternary precursor with an average particle size D50 of 10.5 μm.

[0109] Figure 4 The SEM image of the large-particle high-nickel ternary precursor provided in Comparative Example 1 of the present invention is shown. As can be seen from the figure, cracks exist on the surface of the precursor, and the particle size is relatively uniform with a narrow particle size distribution, which does not achieve the effect of the target large particle size distribution of the present invention.

[0110] The large-particle high-nickel ternary precursor provided in Comparative Example 1 was subjected to D90 and D10 tests using a laser diffraction particle size analyzer (Malvin 3000), and the particle size distribution width span was calculated to be (D90-D10) / D50 = 0.6.

[0111] The test results show that:

[0112] (1) It can be seen from the span data of Examples 1-3 and Comparative Example 1 that the present invention can achieve precise control of the wide particle size distribution of large high-nickel ternary precursors through dynamic feeding control of seed slurry, and maintain the precursor D50 at 7μm to 15μm, thereby achieving wide distribution control of span value from 0.8 to 2.0.

[0113] In the later stages of the reaction, by changing the feed rate (feed volume per hour) of the seed slurry, the particle size of the high-nickel ternary precursor is kept constant within a certain range above and below the average particle size D50 of the target wide-distribution large-particle high-nickel ternary precursor. This ensures continuous output while feeding, reduces material waste in the batch process, shortens the reaction time, and balances preparation efficiency and yield.

[0114] In Comparative Example 1, without seed-guided growth, it is impossible to achieve a wide distribution control of span value from 0.8 to 2.0. The particle size is relatively uniform, the particle size distribution is narrow, and cracks are present on the surface of the precursor. In addition, without dynamic control of the seed crystal to maintain the particle size within a certain range above and below the target average particle size D50, it is also impossible to ensure continuous output while feeding, and the quality of the precursor prepared in a single batch is limited.

[0115] (2) As can be seen from Examples 4-5, the hourly feed volume of the seed slurry in step (2) of the present invention is 1.2% to 6.5% of the volume of the reaction vessel, which can ensure that the prepared large-particle high-nickel ternary precursor has a wide particle size distribution. If the hourly feed volume is too low, there will be more ultra-large particles and fewer medium particles, resulting in a discontinuous particle size distribution. If the hourly feed volume is too high, the seed will lower the average particle size, and the time required to reach the target particle size will be longer, thus affecting the preparation efficiency.

[0116] In summary, this invention achieves precise control of the wide particle size distribution of large-particle high-nickel ternary precursors through dynamic feeding control of the seed slurry. Furthermore, by changing the feeding rate (volume per hour) of the seed slurry in the later stages of the reaction, the particle size of the high-nickel ternary precursors is kept constant within a certain range above and below the average particle size D50 of the target wide-distribution large-particle high-nickel ternary precursors during the reaction. This ensures continuous output while feeding, reduces material waste in batch processes, and increases the preparation quality of wide-distribution large-particle high-nickel ternary precursors in a single batch.

[0117] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for preparing a broadly distributed, large-particle, high-nickel ternary precursor, characterized in that, The preparation method includes the following steps: (1) Add the precipitant solution, complexing agent solution, dispersant, seed slurry and growth substrate to the reaction vessel for the first mixing to obtain the reaction substrate. Then add the nickel-cobalt-manganese ternary salt mixture, precipitant solution and complexing agent solution in parallel to the reaction substrate to carry out the first coprecipitation reaction. (2) After reaching the first particle size D501, a seed slurry with a concentration of 20 g / L to 100 g / L is added. The nickel-cobalt-manganese ternary salt mixture, the precipitant solution, and the complexing agent solution from step (1) are added in parallel to carry out the second co-precipitation reaction. The hourly feed volume of the seed slurry is 1.2% to 6.5% of the volume of the reaction vessel. (3) After reaching the second particle size D502, adjust the hourly feed volume of the seed slurry described in step (2) and connect it to the overflow container to continue the second co-precipitation reaction, so as to reach and maintain the third particle size D503. (4) At the maximum particle size D max When the cutoff particle size is reached, the reaction is stopped, and the slurry in the reaction vessel and the overflow vessel is aged to obtain a wide-distribution, large-particle, high-nickel ternary precursor. The average particle size of the wide-distribution, large-particle, high-nickel ternary precursor is denoted as D50. The first particle size D501 is 45% to 65% of D50, the second particle size D502 is 75% to 95% of D50, the third particle size D503 is 80% to 120% of D50, the average particle size D504 of the seed slurry is 25% to 35% of D50, and the cutoff particle size is 3 times or more of D50. The particle size distribution width of the wide-distribution, large-particle, high-nickel ternary precursor is 0.8~2.

0. The average particle size D50 of the wide-distribution, large-particle, high-nickel ternary precursor is 7 μm to 15 μm.

2. The preparation method according to claim 1, characterized in that, The dispersant in step (1) includes polyethylene glycol and / or hexadecyltrimethylammonium bromide.

3. The preparation method according to claim 1, characterized in that, The amount of dispersant added in step (1) is 1 wt% to 10 wt% of the mass of the nickel-cobalt-manganese ternary salt mixture.

4. The preparation method according to claim 1, characterized in that, In step (1), the molar ratio of Ni:Co:Mn in the nickel-cobalt-manganese ternary salt mixture is x:y:z, where x+y+z=1 and 0.

8. x 0.

97.

5. The preparation method according to claim 1, characterized in that, The total mass concentration of metal salts in the nickel-cobalt-manganese ternary salt mixture in step (1) is 80 g / L to 120 g / L.

6. The preparation method according to claim 1, characterized in that, In step (1), the hourly feed volume of the nickel-cobalt-manganese ternary salt mixture is 2% to 5% of the volume of the reaction vessel.

7. The preparation method according to claim 1, characterized in that, The molar ratio of Ni:Co:Mn in the seed slurry is the same as the molar ratio of Ni:Co:Mn in the nickel-cobalt-manganese ternary salt mixture.

8. The preparation method according to claim 1, characterized in that, The volume of the growth substrate added in step (1) is 40% to 50% of the volume of the reaction vessel.

9. The preparation method according to claim 1, characterized in that, The amount of seed slurry added in step (1) is 0.5wt% to 5wt% of the mass of the growth substrate.

10. The preparation method according to claim 1, characterized in that, Step (1) The temperature of the first mixture is 40℃~80℃.

11. The preparation method according to claim 1, characterized in that, Step (1) The rotation speed of the first mixing is 400 r / min to 700 r / min.

12. The preparation method according to claim 1, characterized in that, The pH of the reaction substrate in step (1) is 9-12.

13. The preparation method according to claim 1, characterized in that, When the complexing agent solution is ammonia water, the total ammonia concentration in the reaction substrate of step (1) is 3g / L~8g / L.

14. The preparation method according to claim 1, characterized in that, Step (1) The first coprecipitation reaction is carried out under an inert atmosphere.

15. The preparation method according to claim 1, characterized in that, Step (1) The temperature of the first coprecipitation reaction is 40℃~80℃.

16. The preparation method according to claim 1, characterized in that, Step (1) The rotation speed of the first coprecipitation reaction is 400 r / min to 700 r / min.

17. The preparation method according to claim 1, characterized in that, In step (1), the pH of the first coprecipitation reaction is 9-12.

18. The preparation method according to claim 1, characterized in that, When the complexing agent solution is ammonia water, in the first coprecipitation reaction process of step (1), the total ammonia concentration in the reaction mixture is 3g / L~8g / L.

19. The preparation method according to claim 1, characterized in that, The second coprecipitation reaction was carried out under an inert atmosphere.

20. The preparation method according to claim 1, characterized in that, The temperature for the second coprecipitation reaction is 40℃~80℃.

21. The preparation method according to claim 1, characterized in that, The rotation speed of the second coprecipitation reaction is 300 r / min to 400 r / min.

22. The preparation method according to claim 1, characterized in that, The pH of the second coprecipitation reaction is 9-12.

23. The preparation method according to claim 1, characterized in that, The preparation method includes the following steps: (1) A precipitant solution with a mass concentration of 200 g / L to 500 g / L, a complexing agent solution with a mass concentration of 9 mol / L to 15 mol / L, a dispersant, a seed slurry, and a growth substrate are added to a reaction vessel. The first mixing is carried out at 40℃ to 80℃ and 400 r / min to 700 r / min to obtain a reaction substrate with a pH of 9 to 12. Under an inert atmosphere, a nickel-cobalt-manganese ternary salt mixture, a precipitant solution, and a complexing agent solution are added to the reaction substrate in parallel. The first coprecipitation reaction is carried out at 40℃ to 80℃, 400 r / min to 700 r / min, and a pH of 9 to 12. When the complexing agent solution is ammonia water, the mass concentration of total ammonia in the reaction mixture during the first coprecipitation reaction is 3 g / L to 8 g / L. In the nickel-cobalt-manganese ternary salt mixture, the molar ratio of Ni:Co:Mn is x:y:z, where x+y+z=1 and 0.

8. x 0.97; the total mass concentration of metal salts in the nickel-cobalt-manganese ternary salt mixture is 80 g / L to 120 g / L; the hourly feed volume of the nickel-cobalt-manganese ternary salt mixture is 2% to 5% of the volume of the reaction vessel; the added volume of the growth substrate is 40% to 50% of the volume of the reaction vessel; the added amount of the seed slurry is 0.5 wt% to 5 wt% of the mass of the growth substrate; when the complexing agent solution is ammonia, the total ammonia mass concentration in the reaction substrate is 3 g / L to 8 g / L; the added amount of the dispersant is 1 wt% to 10 wt% of the mass of the nickel-cobalt-manganese ternary salt mixture. (2) After reaching the first particle size D501, maintain an inert atmosphere, add seed slurry, and continue to add the nickel-cobalt-manganese ternary salt mixture, the precipitant solution and the complexing agent solution in step (1) in parallel flow, and carry out the second coprecipitation reaction at 40℃~80℃, 300r / min~400r / min and pH 9~12. The molar ratio of Ni:Co:Mn in the seed slurry is the same as that in the nickel-cobalt-manganese ternary salt mixture; the concentration of the seed slurry is 20 g / L to 100 g / L; the average particle size D504 of the seed slurry is 25% to 35% of the average particle size D50 of the widely distributed large-particle high-nickel ternary precursor; and the hourly feed volume of the seed slurry is 1.2% to 6.5% of the volume of the reaction vessel. (3) After reaching the second particle size D502, maintain an inert atmosphere, adjust the hourly feed volume of the seed slurry in step (2), and connect it to the overflow container to continue the second co-precipitation reaction, so as to reach and maintain the third particle size D503. (4) At the maximum particle size D max When the cutoff particle size is reached, the reaction is stopped, and the slurry in the reaction vessel and the overflow vessel is aged for 6 to 10 hours at 40℃~80℃, 200r / min~500r / min, pH 10~12, and total alkali concentration of 10g / L~40g / L. After washing and drying at 80℃~120℃, a wide-distribution large-particle high-nickel ternary precursor is obtained. The average particle size of the wide-distribution, large-particle, high-nickel ternary precursor is denoted as D50. The first particle size D501 is 45% to 65% of D50, the second particle size D502 is 75% to 95% of D50, the third particle size D503 is 80% to 120% of D50, and the cutoff particle size is 3 times or more of D50.

24. A widely distributed, large-particle, high-nickel ternary precursor prepared by the preparation method according to any one of claims 1-23, characterized in that, The particle size distribution width of the wide-distribution large-particle high-nickel ternary precursor is 0.8~2.0; the average particle size D50 of the wide-distribution large-particle high-nickel ternary precursor is 7μm~15μm.

25. An application of a widely distributed, large-particle, high-nickel ternary precursor, characterized in that, The wide-distribution, large-particle, high-nickel ternary precursor prepared by the preparation method according to any one of claims 1-23, or the wide-distribution, large-particle, high-nickel ternary precursor according to claim 24, is applied to battery materials.

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