Preparation method of large-particle ternary precursor with high sphericity and low tap density

Abstract

The application discloses a preparation method of large-particle ternary precursors with high sphericity and low tap density, and comprises the following steps: S1, N2 is introduced into a first reaction bottom solution, then ternary solution and adjusting solution are introduced into the first reaction bottom solution at the same time, one-stage reaction is carried out, and a first slurry is obtained; S2, the flow rates of the ternary solution and the adjusting solution are adjusted, two-stage reaction is carried out, and a second slurry is obtained; S3, the second slurry is washed and dehydrated, and a crystal seed is obtained; S4, N2 is introduced into a second reaction bottom solution, then the crystal seed is added, and heating and stirring are carried out, so that a crystal seed mixture is obtained; S5, the ternary solution and the adjusting solution are introduced into the crystal seed mixture, and step-by-step stirring reaction is carried out, so that a slurry is obtained; and S6, the slurry is aged, washed, dehydrated and dried, so that the large-particle ternary precursors with high sphericity and low tap density are obtained.

Description

Technical Field

[0001] This invention relates to the field of new energy materials technology, and in particular to a method for preparing large-particle ternary precursors with high sphericity and low tap density. Background Technology

[0002] With the rapid development of new energy vehicles, the requirements for the lithium battery industry are becoming increasingly stringent. Common lithium batteries are mainly divided into two types: lithium iron phosphate and ternary lithium batteries. Ternary lithium batteries offer numerous advantages, including higher energy density, greater power output, and stronger adaptability. Traditional ternary lithium batteries primarily refer to nickel-cobalt-manganese ternary lithium batteries. Due to the inherent characteristics of the battery, any indicator of the ternary precursor material will affect the battery's performance. Among these, sphericity and tap density are two key indicators for evaluating precursors.

[0003] During the synthesis of nickel-cobalt-manganese ternary hydroxides, as the particle size increases and particle uniformity improves, the tap density increases. Secondary particles are prone to surface cracks and even fragmentation, severely impacting the subsequent sintering process for Li. + The deposition of ions ultimately affects the performance of lithium batteries. Therefore, it is difficult for ternary precursors to meet the requirements of high sphericity and low tap density.

[0004] Therefore, it is necessary to provide a large-particle ternary precursor with high sphericity and low tap density to prevent cracks and fragmentation of the ternary precursor due to its high sphericity. Summary of the Invention

[0005] In view of this, this application provides a method for preparing large-particle ternary precursors with high sphericity and low tap density, in order to solve the problem of how to obtain large-particle ternary precursors with high sphericity and low tap density.

[0006] To achieve the above technical objectives, this application adopts the following technical solution:

[0007] In a first aspect, this application provides a method for preparing a large-particle ternary precursor with high sphericity and low tap density, comprising the following steps:

[0008] S1. N2 is introduced into the first reaction substrate with a pH of 11.4-11.7, and then a ternary solution and an adjusting solution are introduced simultaneously to carry out a reaction to obtain a first slurry with a pH of 9.8-10.0;

[0009] S2. Adjust the flow rates of the ternary solution and the conditioning liquid and introduce them into the first slurry to carry out a two-stage reaction, obtaining a second slurry with a pH value of 9.3-9.8 and containing crystalline particles with a particle size D50 of 3.5-4.0μm;

[0010] S3. Wash and dehydrate the second slurry to obtain seed crystals;

[0011] S4. N2 is introduced into the second reaction substrate with a pH of 10.3-10.6, and then seed crystals are added. The mixture is heated and stirred to obtain a seed crystal mixture.

[0012] S5. The ternary solution and the conditioning solution are introduced into the seed mixture and stirred in stages to obtain a slurry with a pH of 10.0-10.5 and containing crystal particles with a particle size D50 of 13.0-15.0 μm;

[0013] S6. The slurry is aged, washed, dehydrated and dried to obtain a large-particle ternary precursor with high sphericity and low tap density.

[0014] Preferably, the ternary solution comprises 80-120 g / L NiSO4 solution, 80-120 g / L CoSO4 solution, and 80-120 g / L MnSO4 solution; the conditioning solution comprises 10-20 wt% ammonia water and 20-40 wt% NaOH solution.

[0015] Preferably, in step S1, the ammonia concentration of the first reaction substrate is 2.0-6.0 g / L, and the N2 introduction rate is 1.0-4.0 m³ / h.

[0016] Preferably, in step S1, the flow rate of the ternary solution is 200-300 L / h, the flow rate of ammonia is 60-90 L / h, and the flow rate of liquid alkali is 5-15 L / h; the temperature of the first-stage reaction is 40-60℃, the stirring rate is 300-350 r / min, and the reaction time is 10-10.5 h; the ammonia concentration in the first slurry is 2.0-6.0 g / L.

[0017] Preferably, in step S2, the flow rate of the ternary solution is 400-600 L / h, the flow rate of ammonia is 120-180 L / h, and the flow rate of liquid alkali is 10-30 L / h; the temperature of the second-stage reaction is 40-60℃, the stirring rate is 150-300 r / min, and the ammonia concentration in the second slurry is 2.0-6.0 g / L.

[0018] Preferably, in step S3, the washing solution is NaOH solution and pure water, and the water content of the seed crystals is 20-25%.

[0019] Preferably, in step S4, the second reaction substrate includes ammonia and pure water, the ammonia concentration of the second reaction substrate is 5-8 g / L, the N2 flow rate is 1.0-4.0 m³ / h, the heating and stirring temperature is 40-60℃, and the solid content of the seed mixture is 5-15 g / L.

[0020] Preferably, the specific operation of step S5 is as follows:

[0021] S51. The ternary solution, ammonia water, and liquid alkali are introduced into the seed mixture at flow rates of 150-200 L / h, 50-70 L / h, and 10-15 L / h, respectively, to carry out a first-order stirring reaction and obtain the first slurry.

[0022] S52. Adjust the ternary solution, ammonia water, and liquid alkali to 300-350L / h, 100-125L / h, and 15-25L / h respectively, and introduce them into the first slurry to carry out a second-stage stirring reaction to obtain the second slurry.

[0023] S53. Adjust the ternary solution, ammonia water, and liquid alkali to 450-500 L / h, 150-180 L / h, and 20-30 L / h respectively, and introduce them into the second slurry to carry out a three-stage stirring reaction, so as to obtain a slurry with a pH value of 10.0-10.5 and containing crystalline particles with a particle size D50 of 13.0-15.0 μm.

[0024] Preferably, the temperature of the first-stage stirring reaction is 40-60℃, the stirring speed is 180-250 r / min, the reaction time is 20-20.5 h, the pH value of the first slurry is 10.0-10.5, and the ammonia concentration is 5.0-8.0 g / L; the temperature of the second-stage stirring reaction is 40-60℃, the stirring speed is 180-250 r / min, the reaction time is 20-20.5 h, the pH value of the second slurry is 10.0-10.5, and the ammonia concentration is 5.0-7.0 g / L; the temperature of the third-stage stirring reaction is 40-60℃, the stirring speed is 180-250 r / min, the pH value of the second slurry is 10.0-10.5, and the ammonia concentration is 5.0-6.0 g / L.

[0025] Secondly, this application provides a large-particle ternary precursor with high sphericity and low tap density.

[0026] The beneficial effects of this application are as follows: This application obtains a high-nickel ternary precursor with high sphericity, low tap density, and no cracks by first synthesizing seed crystals and then growing grains, and by adjusting the condition parameters of each stage. Attached Figure Description

[0027] Figure 1 The image shows the SEM image of the ternary precursor material obtained in Example 1. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0029] This application provides a method for preparing a large-particle ternary precursor with high sphericity and low tap density, comprising the following steps:

[0030] S1. N2 is introduced into the first reaction substrate with a pH of 11.4-11.7, and then a ternary solution and an adjusting solution are introduced simultaneously to carry out a reaction to obtain a first slurry with a pH of 9.8-10.0;

[0031] S2. Adjust the flow rates of the ternary solution and the conditioning liquid and introduce them into the first slurry to carry out a two-stage reaction, obtaining a second slurry with a pH value of 9.3-9.8 and containing crystalline particles with a particle size D50 of 3.5-4.0μm;

[0032] S3. Wash and dehydrate the second slurry to obtain seed crystals;

[0033] S4. N2 is introduced into the second reaction substrate with a pH of 10.3-10.6, and then seed crystals are added. The mixture is heated and stirred to obtain a seed crystal mixture.

[0034] S5. The ternary solution and the conditioning solution are introduced into the seed mixture and stirred in stages to obtain a slurry with a pH of 10.0-10.5 and containing crystal particles with a particle size D50 of 13.0-15.0 μm;

[0035] S6. The slurry is aged, washed, dehydrated and dried to obtain a large-particle ternary precursor with high sphericity and low tap density.

[0036] Preferably, the ternary solution comprises 80-120 g / L NiSO4 solution, 80-120 g / L CoSO4 solution, and 80-120 g / L MnSO4 solution; the conditioning solution comprises 10-20 wt% ammonia water and 20-40 wt% NaOH solution.

[0037] Preferably, in step S1, the ammonia concentration of the first reaction substrate is 2.0-6.0 g / L, and the N2 introduction rate is 1.0-4.0 m³ / h.

[0038] Preferably, in step S1, the flow rate of the ternary solution is 200-300 L / h, the flow rate of ammonia is 60-90 L / h, and the flow rate of liquid alkali is 5-15 L / h; the temperature of the first-stage reaction is 40-60℃, the stirring rate is 300-350 r / min, and the reaction time is 10-10.5 h; the ammonia concentration in the first slurry is 2.0-6.0 g / L.

[0039] The purpose of a high pH in the first stage of the reaction is to reduce the starting particle size and prevent the starting particle size from being too large to meet the requirements of seed morphology, sphericity and other indicators; the purpose of a high rotation speed in the first stage of the reaction is to control the starting particle size and sphericity; the purpose of a low metal solution flow rate in the first stage of the reaction is to reduce the number of starting particles, which is conducive to rapid growth in the subsequent process and thus avoids the influence of the reaction time process on other indicators.

[0040] Preferably, in step S2, the flow rate of the ternary solution is 400-600 L / h, the flow rate of ammonia is 120-180 L / h, and the flow rate of liquid alkali is 10-30 L / h; the temperature of the second-stage reaction is 40-60℃, the stirring rate is 150-300 r / min, and the ammonia concentration in the second slurry is 2.0-6.0 g / L.

[0041] In both the first and second stage reactions, controlling the ammonia concentration within the target range is beneficial for obtaining particles with rich internal porosity and fine surface morphology, thereby reducing the tap density of the seed crystals and increasing the capacity of the subsequent sintered cathode material.

[0042] During the two-stage reaction, controlling the pH value within the target range is beneficial for controlling the seed morphology, growth rate, and tap density. Within the target rotation speed, the impact on the tap density of the final product is small, and it is beneficial for improving sphericity. Within the metal solution flow rate range specified in this application, it is beneficial for promoting the growth of seed particles.

[0043] Preferably, in step S3, the washing solution is NaOH solution and pure water, and the water content of the seed crystals is 20-25%.

[0044] In this application, steps S1-S3 are the seed crystal synthesis stage, and steps S4-S6 are the particle growth stage.

[0045] Preferably, in step S4, the second reaction substrate includes ammonia and pure water, the ammonia concentration of the second reaction substrate is 5-8 g / L, the N2 flow rate is 1.0-4.0 m³ / h, the heating and stirring temperature is 40-60℃, and the solid content of the seed mixture is 5-15 g / L.

[0046] Preferably, the specific operation of step S5 is as follows:

[0047] S51. The ternary solution, ammonia water, and liquid alkali are introduced into the seed mixture at flow rates of 150-200 L / h, 50-70 L / h, and 10-15 L / h, respectively, to carry out a first-order stirring reaction and obtain the first slurry.

[0048] S52. Adjust the ternary solution, ammonia water, and liquid alkali to 300-350L / h, 100-125L / h, and 15-25L / h respectively, and introduce them into the first slurry to carry out a second-stage stirring reaction to obtain the second slurry.

[0049] S53. Adjust the ternary solution, ammonia water, and liquid alkali to 450-500 L / h, 150-180 L / h, and 20-30 L / h respectively, and introduce them into the second slurry to carry out a three-stage stirring reaction, so as to obtain a slurry with a pH value of 10.0-10.5 and containing crystalline particles with a particle size D50 of 13.0-15.0 μm.

[0050] Preferably, the temperature of the first-stage stirring reaction is 40-60℃, the stirring speed is 180-250 r / min, the reaction time is 20-20.5 h, the pH value of the first slurry is 10.0-10.5, and the ammonia concentration is 5.0-8.0 g / L; the temperature of the second-stage stirring reaction is 40-60℃, the stirring speed is 180-250 r / min, the reaction time is 20-20.5 h, the pH value of the second slurry is 10.0-10.5, and the ammonia concentration is 5.0-7.0 g / L; the temperature of the third-stage stirring reaction is 40-60℃, the stirring speed is 180-250 r / min, the pH value of the second slurry is 10.0-10.5, and the ammonia concentration is 5.0-6.0 g / L.

[0051] During steps S4-S6, the pH values ​​of the first slurry, the second slurry, and the final slurry are all between 10.0 and 10.5, which is conducive to obtaining particles with slender surface morphology and low tap density and can meet the conditions for particle growth.

[0052] In steps S4-S6, the ammonia concentration of the first slurry is within a limited range to control the particle size at startup. During the second and third stirring reactions, the increase in the flow rate of the metal solution will have a certain impact on the tap density. Controlling the ammonia concentration avoids the tap density from increasing and the surface morphology from changing. Adjusting the ammonia concentration in steps S4-S6 is beneficial to obtaining particles with a slender morphology and many pores.

[0053] During steps S4-S6, the rotation speed of the first-stage stirring reaction is within a limited range, which helps to control the starting particle size and sphericity and prevent agglomeration; the rotation speed of the second-stage and third-stage stirring reactions is controlled within a limited range, which helps to control the sphericity, tap density and growth rate of the particles.

[0054] During steps S4-S6, in the first-stage stirring reaction, the flow rate of the ternary liquid is within a limited range to prevent the generation of new grains when the machine is first started; in the second-stage and third-stage stirring reactions, the flow rate of the ternary liquid is within a limited range, which is beneficial to improving the growth rate; in order to avoid the sudden change of stirring reaction conditions affecting the sphericity, this application increases the flow rate of the ternary liquid in stages (second-stage stirring reaction and third-stage stirring reaction).

[0055] This application provides a large-particle ternary precursor with high sphericity and low tap density.

[0056] The following specific embodiments further illustrate this solution.

[0057] Source of raw materials

[0058] Ternary solutions: including 100 g / L NiSO4 aqueous solution, 100 g / L CoSO4 aqueous solution, and 100 g / L MnSO4 aqueous solution.

[0059] Example 1

[0060] A method for preparing a large-particle ternary precursor with high sphericity and low tap density includes the following steps:

[0061] S1. Towards 12m 3 Add 6m to the reaction vessel 3 Pure water, 30wt% NaOH solution, and 16wt% ammonia solution were mixed, stirred, heated to 55℃, and N2 was introduced at a rate of 2.0 m³ / h to obtain the first reaction solution with a pH of 11.6 and an ammonia concentration of 3.5 g / L. Within 0-10 h, the ternary solution, ammonia solution, and liquid alkali were simultaneously added to the reactor at flow rates of 200 L / h, 65 L / h, and 6 L / h, respectively. The rotation speed was controlled at 300 r / min, and the pH value was controlled to drop to 9.9 and the ammonia concentration to 4.0 g / L. The first stage of reaction was completed, and the first slurry was obtained.

[0062] S2. Adjust the ternary solution, ammonia water, and liquid alkali to 400L / h, 125L / h, and 10L / h respectively, control the pH value of the slurry in the reactor to drop to 9.5, the ammonia concentration to 4.0g / L, and the rotation speed to 200r / min, so that the crystal particles continue to grow until the D50 is 4.0μm, then stop feeding and the reaction. The second stage reaction is completed, and the second slurry is obtained.

[0063] S3. The second slurry is washed with NaOH solution and hot pure water and dehydrated to obtain a washed semi-finished product with a water content of 20%, which is the seed crystal;

[0064] S4. At 12m 3 Pure water and ammonia solution were added to the reactor as the second reaction base liquid. The pH value of the second reaction base liquid was 10.5 and the ammonia concentration was 7.0 g / L. Then, seed crystals were added to the reactor and the solid content of the slurry was adjusted to 10 g / L. The slurry in the reactor was heated to 55°C and N2 was introduced at a rate of 3.0 m³ / h. The rotation speed was set to 250 r / min to obtain a seed crystal mixture.

[0065] S5. Within 0-20h, the ternary solution, ammonia, and liquid alkali are introduced into the seed crystal mixture at flow rates of 200L / h, 65L / h, and 15L / h, respectively. The pH of the slurry in the reactor is controlled to decrease to 10.1, the ammonia concentration to 6.0g / L, and the rotation speed to 180r / min. Other conditions remain unchanged as in step S4. After the first-stage stirring reaction is completed, the first slurry is obtained. Within 20-40h, the flow rates of the ternary solution, ammonia, and liquid alkali are adjusted to 350L / h, 122L / h, and 25L / h, respectively, and introduced into the first slurry. The pH of the slurry in the reactor is controlled to decrease. 10.1. With an ammonia concentration of 5.5 g / L and a rotation speed controlled at 180 r / min, and other conditions unchanged from step S4, after the second-stage stirring reaction, a second slurry is obtained. The ternary solution, ammonia water, and liquid alkali are adjusted to 500 L / h, 175 L / h, and 25 L / h respectively and introduced into the second slurry. The pH value of the slurry in the reactor is controlled at 10.0, the ammonia concentration at 5.0 g / L, and the rotation speed controlled at 160 r / min. The crystalline particles are allowed to grow until the particle size D50 is 14.0 μm, at which point the feeding is stopped. After the third-stage stirring reaction, a slurry containing crystalline particles is obtained.

[0066] S6. The slurry is aged, washed, dehydrated and dried to obtain a large-particle ternary precursor with high sphericity and low tap density.

[0067] Example 2

[0068] A method for preparing a large-particle ternary precursor with high sphericity and low tap density includes the following steps:

[0069] S1. Towards 12m 3 Add 6m to the reaction vessel 3 Pure water, 30wt% NaOH solution, and 16wt% ammonia solution were mixed, stirred, heated to 55℃, and N2 was introduced at a rate of 2.0 m³ / h to obtain the first reaction base solution with a pH of 11.4 and an ammonia concentration of 6 g / L. Within 0-10 h, the ternary solution, ammonia solution, and liquid alkali were simultaneously added to the reactor at flow rates of 300 L / h, 90 L / h, and 15 L / h, respectively. The rotation speed was controlled at 250 r / min, and the pH value was controlled to drop to 9.8 and the ammonia concentration to 3.0 g / L. The first stage of reaction was completed, and the first slurry was obtained.

[0070] S2. Adjust the ternary solution, ammonia water, and liquid alkali to 600L / h, 180L / h, and 30L / h respectively, control the pH value of the slurry in the reactor to drop to 9.3 and the ammonia concentration to 3.0g / L, control the rotation speed to 200r / min, and stop feeding the reaction after the crystal particles grow to D50 of 4.0μm. The second stage reaction is completed, and the second slurry is obtained.

[0071] S3. The second slurry is washed with NaOH solution and hot pure water and dehydrated to obtain a washed semi-finished product with a water content of 20%, which is the seed crystal;

[0072] S4. At 12m 3 Pure water and ammonia solution were added to the reactor as the second reaction base liquid. The pH value of the second reaction base liquid was 10.5 and the ammonia concentration was 8.0 g / L. Then, seed crystals were added to the reactor and the solid content of the slurry was adjusted to 10 g / L. The slurry in the reactor was heated to 55°C and N2 was introduced at a rate of 3.0 m³ / h to obtain a seed crystal mixture.

[0073] S5. Within 0-20h, the ternary solution, ammonia, and liquid alkali are introduced into the seed crystal mixture at flow rates of 150L / h, 70L / h, and 10L / h, respectively. The pH of the slurry in the reactor is controlled to decrease to 10.1, the ammonia concentration to 6.0g / L, and the rotation speed to 180r / min. Other conditions remain unchanged as in step S4. After the first-stage stirring reaction is completed, the first slurry is obtained. Within 20-40h, the flow rates of the ternary solution, ammonia, and liquid alkali are adjusted accordingly to 300L / h, 100L / h, and 15L / h, respectively, and introduced into the first slurry. The pH of the slurry in the reactor is controlled to decrease. 10.1. With an ammonia concentration of 5.5 g / L and a rotation speed controlled at 180 r / min, other conditions remain unchanged as in step S4. After the second-stage stirring reaction, a second slurry is obtained. The ternary solution, ammonia water, and liquid alkali are adjusted to 450 L / h, 150 L / h, and 30 L / h respectively and introduced into the second slurry. The pH value of the slurry in the reactor is controlled at 10.2, the ammonia concentration is 5.0 g / L, and the rotation speed is controlled at 160 r / min. The crystalline particles are allowed to grow until the particle size D50 is 14.0 μm, at which point the feeding is stopped. After the third-stage stirring reaction, a slurry containing crystalline particles is obtained.

[0074] S6. The slurry is aged, washed, dehydrated and dried to obtain a large-particle ternary precursor with high sphericity and low tap density.

[0075] Comparative Example 1

[0076] A method for preparing a large-particle ternary precursor is the same as in Example 1, except that the flow rates of the ternary solution, ammonia, and liquid alkali remain unchanged in step S5.

[0077] Comparative Example 2

[0078] A method for preparing a ternary precursor includes the following steps:

[0079] S1. Towards 12m 3 Add 6m to the reaction vessel 3 Add pure water, 30wt% NaOH solution, and 16wt% ammonia solution, stir, heat to 55℃, and purge with 2.0 m³ / h of N2. 2The first reaction solution with a pH of 11.7 and an ammonia concentration of 3.5 g / L was obtained. Within 0-10 h, the ternary solution, ammonia water, and liquid alkali were simultaneously added to the reactor at flow rates of 200 L / h, 65 L / h, and 6 L / h, respectively. The rotation speed was controlled at 250 r / min, and the pH value was controlled to drop to 9.8 and the ammonia concentration to 6.0 g / L. The first stage of reaction was completed, and the first slurry was obtained.

[0080] S2. Adjust the ternary solution, ammonia water, and liquid alkali to 400L / h, 125L / h, and 10L / h respectively, control the pH value of the slurry in the reactor to drop to 9.3 and the ammonia concentration to 3.0g / L, control the rotation speed to 200r / min, and stop feeding the reaction after the crystal particles grow to D50 of 4.0μm. The second stage reaction is completed, and the second slurry is obtained.

[0081] S3. The ternary solution, ammonia, and liquid alkali are fed into the second slurry at flow rates of 200 L / h, 65 L / h, and 15 L / h, respectively. The pH value of the slurry in the reactor is controlled to drop to 10.1, the ammonia concentration to drop to 6.0 g / L, and the rotation speed to drop to 180 r / min. The crystalline particles are allowed to grow until the particle size D50 is 14.0 μm, at which point the feeding is stopped. After the three-stage stirring reaction is completed, a slurry containing crystalline particles is obtained.

[0082] S4. The slurry is aged, washed, dehydrated and dried to obtain a large-particle ternary precursor with high sphericity and low tap density.

[0083] Testing and Evaluation

[0084] The ternary precursor obtained in Example 1 was examined by 5000x electron microscopy, and the results are as follows: Figure 1 As shown, the ternary precursor obtained in this application has high sphericity, low tap density, and no cracking.

[0085] The tap density of the ternary precursors obtained in Examples 1-2 and Comparative Examples 1-2 was tested, and the results are shown in Table 1.

[0086] Table 1. Results of tap density test

[0087]

[0088] This application obtains a high-nickel ternary precursor with high sphericity, low tap density, and no cracks by first synthesizing seed crystals and then growing grains, and by adjusting the condition parameters at each stage.

[0089] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a large-particle ternary precursor with high sphericity and low tap density, characterized in that, Includes the following steps: S1. N2 is introduced into the first reaction substrate with a pH of 11.4-11.7, and then a ternary solution and an adjusting solution are introduced simultaneously to carry out a reaction to obtain a first slurry with a pH of 9.8-10.0; S2. Adjust the flow rates of the ternary solution and the conditioning liquid and introduce them into the first slurry to carry out a two-stage reaction, thereby obtaining a second slurry with a pH value of 9.3-9.8 and containing crystalline particles with a particle size D50 of 3.5-4.0μm; S3. The second slurry is washed and dehydrated to obtain seed crystals; S4. N2 is introduced into the second reaction substrate with a pH of 10.3-10.6, and then seed crystals are added. The mixture is heated and stirred to obtain a seed crystal mixture. S5. The ternary solution and the conditioning liquid are introduced into the seed mixture and stirred in stages to obtain a slurry with a pH of 10.0-10.5 and containing crystalline particles with a particle size D50 of 13.0-15.0 μm; S6. The slurry is aged, washed, dehydrated and dried to obtain the large-particle ternary precursor with high sphericity and low tap density; The ternary solution comprises 80-120 g / L NiSO4 solution, 80-120 g / L CoSO4 solution, and 80-120 g / L MnSO4 solution; the conditioning solution comprises 10-20 wt% ammonia water and 20-40 wt% NaOH solution. The specific operation of step S5 is as follows: S51. The ternary solution, ammonia water, and liquid alkali are introduced into the seed mixture at flow rates of 150-200 L / h, 50-70 L / h, and 10-15 L / h, respectively, to carry out a first-order stirring reaction and obtain the first slurry. S52. Adjust the ternary solution, ammonia water, and liquid alkali to 300-350L / h, 100-125L / h, and 15-25L / h respectively, and introduce them into the first slurry to carry out a second-stage stirring reaction to obtain the second slurry; S53. Adjust the ternary solution, ammonia water, and liquid alkali to 450-500 L / h, 150-180 L / h, and 20-30 L / h respectively, and introduce them into the second slurry to carry out a three-stage stirring reaction, thereby obtaining a slurry with a pH value of 10.0-10.5 and containing crystalline particles with a particle size D50 of 13.0-15.0 μm.

2. The method for preparing large-particle ternary precursors with high sphericity and low tap density according to claim 1, characterized in that, In step S1, the ammonia concentration of the first reaction substrate is 2.0-6.0 g / L, and the N2 introduction rate is 1.0-4.0 m³ / h.

3. The method for preparing large-particle ternary precursors with high sphericity and low tap density according to claim 1, characterized in that, In step S1, the flow rate of the ternary solution is 200-300 L / h, the flow rate of ammonia is 60-90 L / h, and the flow rate of liquid alkali is 5-15 L / h; the temperature of the first-stage reaction is 40-60℃, the stirring rate is 300-350 r / min, and the reaction time is 10-10.5 h; the ammonia concentration in the first slurry is 2.0-6.0 g / L.

4. The method for preparing large-particle ternary precursors with high sphericity and low tap density according to claim 1, characterized in that, In step S2, the flow rate of the ternary solution is 400-600 L / h, the flow rate of ammonia is 120-180 L / h, and the flow rate of liquid alkali is 10-30 L / h; the temperature of the two-stage reaction is 40-60℃, and the stirring rate is 150-300 r / min; the ammonia concentration in the second slurry is 2.0-6.0 g / L.

5. The method for preparing large-particle ternary precursors with high sphericity and low tap density according to claim 1, characterized in that, In step S3, the washing solution is NaOH solution and pure water, and the water content of the seed crystal is 20-25%.

6. The method for preparing large-particle ternary precursors with high sphericity and low tap density according to claim 1, characterized in that, In step S4, the second reaction substrate includes ammonia and pure water, the ammonia concentration of the second reaction substrate is 5-8 g / L, the flow rate of N2 is 1.0-4.0 m³ / h, the temperature of the heating and stirring reaction is 40-60℃, and the solid content of the seed mixture is 5-15 g / L.

7. The method for preparing large-particle ternary precursors with high sphericity and low tap density according to claim 1, characterized in that, The first-stage stirring reaction is carried out at a temperature of 40-60℃, a stirring speed of 180-250 r / min, and a reaction time of 20-20.5 h. The pH value of the first slurry is 10.0-10.5, and the ammonia concentration is 5.0-8.0 g / L. The second-stage stirring reaction is carried out at a temperature of 40-60℃, a stirring speed of 180-250 r / min, and a reaction time of 20-20.5 h. The pH value of the second slurry is 10.0-10.5, and the ammonia concentration is 5.0-7.0 g / L. The third-stage stirring reaction is carried out at a temperature of 40-60℃, a stirring speed of 180-250 r / min, and the pH value of the second slurry is 10.0-10.5, and the ammonia concentration is 5.0-6.0 g / L.

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