Wide-distribution large-particle high-nickel ternary precursor as well as preparation method and application thereof

Abstract

The invention relates to a wide-distribution large-particle high-nickel ternary precursor as well as a preparation method and application thereof. The preparation method comprises the following steps: adding a precipitant solution, a complexing agent solution, a dispersing agent, seed crystal slurry and a growth base solution into a reaction container; adding a nickel-cobalt-manganese ternary salt mixed solution, a precipitant solution and a complexing agent solution into the obtained reaction base solution in a parallel flow manner, and carrying out first coprecipitation; after the first particle size is reached, adding the seed crystal slurry, and carrying out second coprecipitation; after the second particle size is reached, adjusting the feeding volume of the seed crystal slurry per hour, introducing the seed crystal slurry into an overflow container, continuously carrying out second coprecipitation, and reaching and maintaining the seed crystal slurry at a third particle size; and when the maximum particle size reaches the cut-off particle size, stopping the reaction, and aging to obtain the wide-distribution large-particle high-nickel ternary precursor. According to the invention, wide particle size distribution regulation and control of the large-particle high-nickel ternary precursor are realized through dynamic feeding of the seed crystal slurry, feeding and continuous discharging can be realized at the same time, material waste of an intermittent method is reduced, and the preparation yield of a single-batch precursor is increased.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy battery material precursor preparation, and in particular to a wide-distribution large-particle high-nickel ternary precursor, and a preparation method and application thereof. Background Art

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

[0003] High-nickel cathode materials have high energy density. As the nickel content increases, the specific capacity of the material increases significantly (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 demand for long driving range in areas 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 achieve both high sphericity and high tap density.

[0004] Research has shown that high-nickel ternary precursor materials with a wide particle size distribution have advantages such as high compacted 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 co-precipitation, which uses a nickel, cobalt, and manganese metal salt solution as the raw material, along with a precipitant and a complexing agent. The three react in a reactor to produce the final product.

[0005] CN115072794A discloses a preparation of a ternary precursor with controllable particle size distribution. The method first prepares seed crystals, then performs subsequent growth, and controls the particle size distribution width of the product by continuously adding seed crystals. The specific process includes: adding the seed crystal material to the growth kettle at a constant rate by continuous flow addition, adding a mixed metal salt solution, sodium hydroxide solution and ammonia water to the growth kettle in parallel for reaction, controlling the reaction temperature, pH and ammonia concentration, and stopping the feeding when it is detected that the D50 of the material in the growth kettle reaches 8.0 to 20.0 μm and the K90 reaches 0.7 to 1.6, and continuing stirring and aging for 1 to 2 hours to obtain the desired ternary precursor product.

[0006] CN116216792A discloses a method for preparing a spherical high-nickel ternary precursor material with wide distribution and no fine powder by a seed controlled precipitation method. A mixed salt solution, a complexing agent solution, a precipitant solution, and a seed slurry are pumped into a reactor in parallel under the conditions of protective gas and stirring. Co-precipitation realizes 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. The slurry that has reacted to the end point is post-treated to obtain a spherical high-nickel precursor material with wide distribution and no fine powder.

[0007] It can be seen from the above-mentioned existing technologies that although the preparation of (high nickel) ternary precursors with a wide particle size distribution can be achieved, there is a common problem of low quality of precursors produced in a single batch, and it is impossible to achieve simultaneous feeding and discharging, and continuous production. As a result, if large-scale preparation of precursors is to be achieved, the same process needs to be repeated many times (intermittent method), and a large amount of material will be wasted during the repetition, resulting in increased preparation costs; in addition, the ratio of seed crystals to ternary liquid flow rates is continuously kept constant, and precise control of particle size distribution cannot be achieved.

[0008] Therefore, how to effectively increase the mass of high-nickel ternary precursors produced in a single batch, realize simultaneous feeding and discharging, and at the same time take into account the precise control to prepare high-nickel ternary precursors with a wide particle size distribution has become a problem that needs to be solved urgently. Summary of the Invention

[0009] To solve the above technical problems, the present invention provides a wide-distribution large-particle high-nickel ternary precursor and its preparation method and application. The present invention realizes precise control of the wide particle size distribution of the large-particle high-nickel ternary precursor through dynamic feeding control of the seed slurry, and in the later stage of the reaction, by changing the feeding rate of the seed slurry (feed volume per hour), the particle size of the high-nickel ternary precursor during the reaction is constant within a certain range of the average particle size D50 of the target wide-distribution large-particle high-nickel ternary precursor, thereby ensuring continuous discharging while feeding, reducing the material waste problem of the intermittent method, and increasing the preparation quality of a single batch of wide-distribution large-particle high-nickel ternary precursor.

[0010] To achieve this object, the present invention adopts the following technical solutions:

[0011] In a first aspect, the present invention provides a method for preparing a ternary precursor with wide distribution, large particles and high nickel content, the preparation method comprising the following steps:

[0012] (1) adding a precipitant solution, a complexing agent solution, a dispersant, a seed slurry, and a growth base solution into a reaction vessel, performing a first mixing to obtain a reaction base solution, and then adding a nickel-cobalt-manganese ternary salt mixture, a precipitant solution, and a complexing agent solution concurrently into the reaction base solution to perform a first coprecipitation reaction;

[0013] (2) After the first particle size D501 is reached, the seed slurry is added, and the nickel-cobalt-manganese ternary salt mixed solution, the precipitant solution, and the complexing agent solution in step (1) are continuously added in parallel to perform a second coprecipitation reaction;

[0014] (3) After reaching the second particle size D502, the hourly feed volume of the seed slurry in step (2) is adjusted, and an overflow container is connected to continue the second coprecipitation reaction 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 container and the overflow container is aged to obtain a ternary precursor with wide distribution, large particles and high nickel content.

[0016] The present invention realizes precise regulation of the wide particle size distribution of large-particle high-nickel ternary precursors through dynamic feed control of seed slurry, and can also increase the preparation quality of single batch wide distribution large-particle high-nickel ternary precursors. In the early stage of the reaction, the seed slurry and the reaction raw materials are first added at a constant feed rate to promote the growth of particles and the increase of particle size. When the particle size increases to a certain range, the seed slurry feed volume per hour is then regulated in real time to maintain the particle size constant within a certain range above and below the average particle size D50 of the target wide distribution large-particle high-nickel ternary precursor, thereby avoiding the continuous increase of the precursor particle size, and thus ensuring continuous discharging while feeding, thereby increasing the preparation quality of single batch wide distribution large-particle high-nickel ternary precursors. The obtained wide distribution large-particle high-nickel ternary precursor has a higher tap density and compacted density, so that the high-nickel positive electrode material can have better electrochemical performance.

[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 recorded as D50, and the first particle size D501 is 45% to 65% of the D50, for example, 45%, 48%, 50%, 52%, 55%, 58%, 60%, 62% or 65%, etc.

[0018] In the present invention, after regulating 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 wide-distributed large-particle high-nickel ternary precursor, it will take a long time to reach the target particle size, thereby affecting the preparation efficiency; if the first particle size D501 is too large relative to the average particle size D50 of the wide-distributed large-particle high-nickel ternary precursor, it will result in more oversized particles, fewer medium particles, and discontinuous particle size distribution.

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

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

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

[0022] In the present invention, regulating the cutoff particle size to 3 times or more of the D50 can allow enough time to overflow sufficient product, thereby ensuring maximum production output; if the cutoff particle size is too small, it will lead to a short material connection time and a reduction in the single precursor production output.

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

[0024] Preferably, the mass concentration of the precipitant solution in step (1) is 200 g / L to 500 g / L, for example, 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) comprises any one of ammonia water, oxalic acid solution, citric acid solution or ascorbic acid solution, or a combination of at least two thereof.

[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 cetyltrimethylammonium bromide.

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

[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, for example, 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 types of compounds corresponding to the nickel source, cobalt source and manganese source include sulfate and / or nitrate.

[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 container, for example, 2%, 2.5%, 3%, 3.5%, 4%, 4.5% or 5%.

[0033] As a preferred technical solution 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, for example, 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 recorded as D50, and the average particle size D504 of the seed slurry is 25% to 35% of the D50, for example, 25%, 28%, 30%, 32% or 35%.

[0036] Preferably, the growth base liquid in step (1) comprises pure water.

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

[0038] Preferably, the amount of the seed slurry added in step (1) is 0.5wt% to 5wt% of the mass of the growth base solution, for example, 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°C to 80°C, for example, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C or 80°C.

[0040] Preferably, the rotation 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 base solution 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 aqueous ammonia, the mass concentration of total ammonia in the reaction base solution in step (1) is 3 g / L to 8 g / L, for example, 3 g / L, 4 g / L, 5 g / L, 6 g / L, 7 g / L or 8 g / 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°C to 80°C, for example, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C or 80°C.

[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, for example, 9, 9.5, 10, 10.5, 11, 11.5 or 12.

[0048] Preferably, when the complexing agent solution is aqueous ammonia, during the first coprecipitation reaction in step (1), the mass concentration of total ammonia in the reaction mixture is 3 g / L to 8 g / L, for example, 3 g / L, 4 g / L, 5 g / L, 6 g / L, 7 g / L or 8 g / 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 the present invention, the hourly feed volume of the seed slurry in step (2) is regulated to be 1.2% to 6.5% of the volume of the reaction vessel. If the hourly feed volume is too low, it will result in more oversized particles, fewer medium particles, and discontinuous particle size distribution; if the hourly feed volume is too high, it will cause the seed crystals to lower the average particle size, and it will take a long time to reach the target particle size, thereby 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°C to 80°C, for example, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C or 80°C.

[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 9-12, for example, 9, 9.5, 10, 10.5, 11, 11.5 or 12.

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

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

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

[0059] Preferably, the internal reaction rotation speed of the overflow container 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.

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

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

[0062] Preferably, the pH of the aging in step (4) is 10-12, for example, 10, 10.2, 10.5, 10.8, 11, 11.2, 11.5, 11.8 or 12.

[0063] Preferably, the aging rotation 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 in step (4) is completed, washing and drying are also performed in sequence.

[0066] Preferably, the washing comprises alkali washing and water washing performed sequentially.

[0067] Preferably, the drying temperature is 80°C to 120°C, for example, 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C or 120°C.

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

[0069] (1) adding 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 base solution into a reaction vessel, performing a first mixing at 40° C. to 80° C. and 400 r / min to 700 r / min to obtain a reaction base solution with a pH of 9 to 12, and then adding a nickel-cobalt-manganese ternary salt mixed solution, a precipitant solution and a complexing agent solution into the reaction base solution in parallel under an inert atmosphere, and performing a first coprecipitation reaction 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 water, the mass concentration of total ammonia in the reaction mixture during the first coprecipitation reaction is 3 g / L to 8 g / L;

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

[0071] (2) After reaching the first particle size D501, maintaining an inert atmosphere, adding a seed slurry, continuing to add the nickel-cobalt-manganese ternary salt mixed solution, the precipitant solution, and the complexing agent solution in step (1) in parallel, and performing a second coprecipitation reaction at 40° C. to 80° C., 300 rpm to 400 rpm, and a pH of 9 to 12;

[0072] 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; 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 wide-distribution large-particle high-nickel ternary precursor; 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, maintaining an inert atmosphere, adjusting the hourly feed volume of the seed slurry in step (2), connecting to an overflow container, and continuing the second coprecipitation reaction 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 container and the overflow container is aged for 6 hours to 10 hours at 40° C. to 80° C., 200 r / min to 500 r / min, a pH of 10 to 12, and a total alkali concentration of 10 g / L to 40 g / L, and then washed and dried at 80° C. to 120° C. to obtain a ternary precursor with wide distribution, large particles, and high nickel content;

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

[0076] In the 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 span 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, etc.

[0077] In the present 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 7 μm to 15 μm, for example, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm or 15 μm, etc.

[0079] In the third aspect, the present invention also provides an application of a wide-distribution, large-particle, high-nickel ternary precursor, and 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) The present invention realizes precise control of the wide particle size distribution of large-particle high-nickel ternary precursors through dynamic feeding control of seed slurry, while also increasing the preparation quality of a single batch of wide-distribution large-particle high-nickel ternary precursors, while taking into account both preparation efficiency and output.

[0082] 2) The wide-distribution large-particle high-nickel ternary precursor obtained in the present invention has a wide particle size distribution, and the precursor D50 is maintained at 7μm to 15μm, achieving wide distribution regulation of span value 0.8 to 2.0, and has a higher tap density and compaction density, so that the high-nickel positive electrode material can have better electrochemical performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] Figure 1 This is an SEM image of the widely distributed, large-particle, high-nickel ternary precursor provided in Example 1 of the present invention.

[0084] Figure 2 This is an SEM image of the widely distributed, large-particle, high-nickel ternary precursor provided in Example 2 of the present invention.

[0085] Figure 3 This is an SEM image of the widely distributed, large-particle, high-nickel ternary precursor provided in Example 3 of the present invention.

[0086] Figure 4 This is an SEM image of the large-particle high-nickel ternary precursor provided in Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0087] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through 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 shall be subject to the claims.

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

[0089] Example 1

[0090] This embodiment provides a method for preparing a ternary precursor with wide distribution, large particles and high nickel content, the preparation method comprising the following steps:

[0091] (1) Determine the target wide distribution large particle high nickel ternary precursor average particle size D50 is 10.5 μm, prepare nickel cobalt manganese ternary salt mixture with a molar ratio of Ni:Co:Mn of 0.93:0.05:0.02, and the total mass concentration of the three metal salts of nickel sulfate, cobalt sulfate and manganese sulfate is 80 g / L; prepare sodium hydroxide solution with a mass concentration of 400 g / L and ammonia water with a mass concentration of 10 mol / L; prepare seed slurry with a molar ratio of Ni:Co:Mn of 0.93:0.05:0.02, and the concentration of the seed slurry is 20 g / L;

[0092] Sodium hydroxide solution, ammonia water, polyethylene glycol, and seed slurry were added to a reactor, and pure water (50% by volume of the reactor) was added as a growth base solution. The mass of the seed slurry was 5 wt% of the mass of the pure water. The mixture was first mixed at 60° C. and 600 rpm to obtain a reaction base solution 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, a sodium hydroxide solution, and aqueous ammonia were added concurrently to the reaction bottom solution. The nickel-cobalt-manganese ternary salt mixture was fed at a rate of 3% of the reactor volume per hour. A first coprecipitation reaction was carried out at 60° C., 600 rpm, and a pH of 12. The total ammonia concentration in the reaction mixture was 8 g / L.

[0094] (2) When the first particle size D501 of the particles in the reactor reaches 45% of the target D50, a nitrogen atmosphere is maintained, and a seed slurry (the same seed slurry as in step (1)) 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 is added. The nickel-cobalt-manganese ternary salt mixed solution, the precipitant solution, and the complexing agent solution in step (1) are continued to be added in parallel, and a second coprecipitation reaction is carried out at 60° C., 400 r / min, and a pH of 12;

[0095] (3) When the second particle size D502 of the particles in the reactor reaches 85% of the target D50, the nitrogen atmosphere is maintained, and the hourly feed volume of the seed slurry in step (2) is dynamically and real-time adjusted so that the particle size of the high-nickel ternary precursor in the reactor reaches and is maintained at the third particle size D503, and D503 is 90% to 110% of the target D50. At this time, the overflow kettle is connected to collect the overflow slurry of the reactor. The reaction temperature in the overflow kettle is maintained at 60°C, the rotation speed is 300r / min, and the interior is in a nitrogen atmosphere. When the overflow slurry is close to 85% of the overflow kettle volume, it is purified with a concentrator, and part of the mother liquor is discharged to increase the volume of 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 the slurries in the reactor and overflow kettle were aged at 60°C, pH 12, total alkali concentration 40g / L, and rotation speed 500r / min for 8h. After the aging, they were washed with alkali 4 times, washed with water 4 times, and dried at 120°C to obtain a wide-distribution large-particle high-nickel ternary precursor with an average particle size D50 of 10.5μm.

[0097] Figure 1 The SEM image of the wide-distribution large-particle high-nickel ternary precursor provided by Example 1 of the present invention is shown. As can be seen from the figure, the particle size distribution of the particles is relatively wide, there is no fine powder, and no cracks.

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

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

[0100] Figure 2 The SEM image of the wide-distribution large-particle high-nickel ternary precursor provided by Example 2 of the present invention is shown. As can be seen from the figure, the particle size distribution of the particles is relatively wide, there is no fine powder, and no cracks.

[0101] Figure 3 The SEM image of the wide-distribution large-particle high-nickel ternary precursor provided by Example 3 of the present invention is shown. As can be seen from the figure, the particle size distribution of the particles is relatively wide and there is no fine 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, which comprises the following steps:

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

[0107] Sodium hydroxide solution, ammonia water, and polyethylene glycol were added to a reaction kettle, and pure water (50% of the volume of the reaction kettle) was added as a growth base solution. The mixture was first mixed at 60° C. and 600 rpm to obtain a reaction base solution with a pH of 12 and a total ammonia concentration of 8 g / L.

[0108] Under a nitrogen atmosphere, a nickel-cobalt-manganese ternary salt mixture, a sodium hydroxide solution and an ammonia solution are added to the reaction bottom liquid in parallel, the hourly feed volume of the nickel-cobalt-manganese ternary salt mixture is 3% of the volume of the reactor, and a coprecipitation reaction is carried out at 60°C, 600r / min and pH 12. The mass concentration of total ammonia in the reaction mixture is 8g / L; after the reaction, the slurry in the reactor is aged for 8h at 60°C, pH 12, a total alkali concentration of 40g / L and a rotation speed of 500r / min. After the aging, it is washed with alkali 4 times, washed with water 4 times, and dried at 120°C to obtain a large-particle high-nickel ternary precursor with an average particle size D50 of 10.5μm.

[0109] Figure 4 The SEM image of the large-particle high-nickel ternary precursor provided by Comparative Example 1 of the present invention is shown. It can be seen from the figure that cracks exist on the surface of the precursor, and the particle size of the particles is relatively uniform and the particle size distribution is narrow, which does not achieve the effect of large particles with a wide particle size distribution as the target 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 (Malvern 3000), and the particle size distribution width span = (D90-D10) / D50 = 0.6 was calculated.

[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-particle high-nickel ternary precursors through dynamic feeding control of the seed slurry, and the precursor D50 is maintained at 7μm to 15μm, achieving wide distribution control of span values of 0.8 to 2.0.

[0113] In the later stage of the reaction, by changing the feed rate of the seed slurry (feed volume per hour), 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 during the reaction, thereby ensuring continuous discharge while feeding, reducing intermittent material waste and shortening the reaction time, taking into account both preparation efficiency and output.

[0114] In Comparative Example 1, without using seed crystals to guide growth, wide distribution control of span values of 0.8 to 2.0 cannot be achieved, the particle size is relatively uniform, the particle size distribution is narrow, and cracks exist on the surface of the precursor. In addition, if the seed crystals are not dynamically controlled to maintain the particle size within a certain range above and below the target average particle size D50, it is impossible to ensure continuous discharge while feeding, and the quality of the precursor prepared in a single batch is limited.

[0115] (2) It can be seen from Examples 4-5 that the hourly feed volume of the seed slurry in the control 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, it will result in more oversized particles, fewer medium particles, and discontinuous particle size distribution; if the hourly feed volume is too high, it will cause the seed crystals to lower the average particle size, and it will take a long time to reach the target particle size, thereby affecting the preparation efficiency.

[0116] In summary, the present invention realizes precise control of the wide particle size distribution of large-particle high-nickel ternary precursor through dynamic feed control of seed slurry, and changes the feed rate of seed slurry (feed volume per hour) in the later stage of the reaction, so that the particle size of the high-nickel ternary precursor is constant within a certain range of the average particle size D50 of the target wide-distribution large-particle high-nickel ternary precursor during the reaction, thereby ensuring continuous discharge while feeding, reducing the material waste problem of the intermittent method, and increasing the preparation quality of a single batch of wide-distribution large-particle high-nickel ternary precursor.

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

Claims

1. A method for preparing a wide-distribution, large-particle, high-nickel ternary precursor, characterized in that: The preparation method comprises the following steps: (1) adding a precipitant solution, a complexing agent solution, a dispersant, a seed slurry, and a growth base solution into a reaction vessel, performing a first mixing to obtain a reaction base solution, and then adding a nickel-cobalt-manganese ternary salt mixture, a precipitant solution, and a complexing agent solution concurrently into the reaction base solution to perform a first coprecipitation reaction; (2) After the first particle size D501 is reached, the seed slurry is added, and the nickel-cobalt-manganese ternary salt mixed solution, the precipitant solution, and the complexing agent solution in step (1) are continuously added in parallel to perform a second coprecipitation reaction; (3) After reaching the second particle size D502, the hourly feed volume of the seed slurry in step (2) is adjusted, and an overflow container is connected to continue the second coprecipitation reaction 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 container and the overflow container is aged to obtain a ternary precursor with wide distribution, large particles and high nickel content.

2. The preparation method according to claim 1, characterized in that The average particle size of the wide-distribution large-particle high-nickel ternary precursor is recorded as D50, and the first particle size D501 is 45% to 65% of the D50; Preferably, the average particle size of the wide-distribution large-particle high-nickel ternary precursor is recorded as D50, and the second particle size D502 is 75% to 95% of the D50; Preferably, the average particle size of the wide-distribution large-particle high-nickel ternary precursor is recorded as D50, and the third particle size D503 is 80% to 120% of the D50; Preferably, the average particle size of the wide-distribution large-particle high-nickel ternary precursor is recorded as D50, and the cutoff particle size is 3 times or more of the D50.

3. The preparation method according to claim 1 or 2, characterized in that The dispersant in step (1) comprises polyethylene glycol and / or hexadecyltrimethylammonium bromide; Preferably, the amount of the 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 any one of claims 1 to 3, characterized in that In the nickel-cobalt-manganese ternary salt mixture of step (1), the molar ratio of Ni:Co:Mn is x:y:z, x+y+z=1, 0.8≤x≤0.97; Preferably, the total mass concentration of the metal salts in the nickel-cobalt-manganese ternary salt mixture in step (1) is 80 g / L to 120 g / L; 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 container.

5. The preparation method according to any one of claims 1 to 4, 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; Preferably, the concentration of the seed slurry is 20 g / L to 100 g / L; Preferably, the average particle size of the broadly distributed large-particle high-nickel ternary precursor is recorded as D50, and the average particle size D504 of the seed slurry is 25% to 35% of the D50; Preferably, the volume of the growth base solution added in step (1) is 40% to 50% of the volume of the reaction container; Preferably, the amount of the seed slurry added in step (1) is 0.5 wt% to 5 wt% of the mass of the growth base solution.

6. The preparation method according to any one of claims 1 to 5, characterized in that Step (1) the temperature of the first mixing is 40°C to 80°C; Preferably, the rotation speed of the first mixing in step (1) is 400 r / min to 700 r / min; Preferably, the pH of the reaction base solution in step (1) is 9 to 12; Preferably, when the complexing agent solution is ammonia water, the mass concentration of total ammonia in the reaction base solution in step (1) is 3 g / L to 8 g / L; Preferably, the first coprecipitation reaction in step (1) is carried out under an inert atmosphere; Preferably, the temperature of the first coprecipitation reaction in step (1) is 40° C. to 80° C.; Preferably, the rotation speed of the first coprecipitation reaction in step (1) is 400 r / min to 700 r / min; Preferably, the pH of the first coprecipitation reaction in step (1) is 9 to 12; Preferably, when the complexing agent solution is aqueous ammonia, during the first coprecipitation reaction in step (1), the mass concentration of total ammonia in the reaction mixture is 3 g / L to 8 g / L.

7. The preparation method according to any one of claims 1 to 6, characterized in that The hourly feed volume of the seed slurry in step (2) is 1.2% to 6.5% of the volume of the reaction vessel; Preferably, the second coprecipitation reaction is carried out under an inert atmosphere; Preferably, the temperature of the second coprecipitation reaction is 40°C to 80°C; Preferably, the rotation speed of the second coprecipitation reaction is 300 r / min to 400 r / min; Preferably, the pH of the second coprecipitation reaction is 9-12.

8. The preparation method according to claim 1, characterized in that The preparation method comprises the following steps: (1) adding 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 base solution into a reaction vessel, performing a first mixing at 40° C. to 80° C. and 400 r / min to 700 r / min to obtain a reaction base solution with a pH of 9 to 12, and then adding a nickel-cobalt-manganese ternary salt mixed solution, a precipitant solution and a complexing agent solution into the reaction base solution in parallel under an inert atmosphere, and performing a first coprecipitation reaction 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 water, the mass concentration of total ammonia in the reaction mixture during the first coprecipitation reaction is 3 g / L to 8 g / L; Wherein, in the nickel-cobalt-manganese ternary salt mixture, the molar ratio of Ni:Co:Mn is x:y:z, x+y+z=1, 0.8≤x≤0.97; the total mass concentration of metal salts in the nickel-cobalt-manganese ternary salt mixture is 80g / L to 120g / L; the hourly feed volume of the nickel-cobalt-manganese ternary salt mixture is 2% to 5% of the volume of the reaction container; the added volume of the growth base solution is 40% to 50% of the volume of the reaction container; the added amount of the seed slurry is 0.5wt% to 5wt% of the mass of the growth base solution; when the complexing agent solution is ammonia water, the mass concentration of total ammonia in the reaction base solution is 3g / L to 8g / L; the added amount of the dispersant is 1wt% to 10wt% of the mass of the nickel-cobalt-manganese ternary salt mixture; (2) After reaching the first particle size D501, maintaining an inert atmosphere, adding a seed slurry, continuing to add the nickel-cobalt-manganese ternary salt mixed solution, the precipitant solution, and the complexing agent solution in step (1) in parallel, and performing a second coprecipitation reaction at 40° C. to 80° C., 300 rpm to 400 rpm, and a pH of 9 to 12; 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; 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 wide-distribution large-particle high-nickel ternary precursor; 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, maintaining an inert atmosphere, adjusting the hourly feed volume of the seed slurry in step (2), connecting to an overflow container, and continuing the second coprecipitation reaction 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 container and the overflow container is aged for 6 hours to 10 hours at 40° C. to 80° C., 200 r / min to 500 r / min, a pH of 10 to 12, and a total alkali concentration of 10 g / L to 40 g / L, and then washed and dried at 80° C. to 120° C. to obtain a ternary precursor with wide distribution, large particles, and high nickel content; Among them, the average particle size of the wide-distribution large-particle high-nickel ternary precursor is recorded as D50, the first particle size D501 is 45% to 65% of the D50, the second particle size D502 is 75% to 95% of the D50, the third particle size D503 is 80% to 120% of the D50, and the cutoff particle size is 3 times or more of the D50.

9. A ternary precursor with wide distribution, large particles and high nickel content prepared by the preparation method according to any one of claims 1 to 8, characterized in that: The particle size distribution width span of the wide-distribution large-particle high-nickel ternary precursor is 0.8 to 2.0; Preferably, the average particle size D50 of the wide-distribution large-particle high-nickel ternary precursor is 7 μm to 15 μm.

10. Application of a wide-distribution 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 to 8, or the wide distribution large particle high nickel ternary precursor according to claim 9, is applied to battery materials.

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