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

Abstract

The invention discloses a preparation method of a large-particle ternary precursor with high sphericity degree and low tap density, which comprises the following steps: S1, introducing N2 into a first reaction base solution, simultaneously introducing a ternary solution and a regulating solution, and carrying out first-stage reaction to obtain first slurry; s2, adjusting the introduction flow of the ternary solution and the adjusting solution, and carrying out a second-stage reaction to obtain a second slurry; s3, washing and dehydrating the second slurry to obtain a seed crystal; s4, introducing N2 into the second reaction base solution, then adding a seed crystal, heating and stirring to obtain a seed crystal mixture; s5, introducing the ternary solution and the adjusting solution into the seed crystal mixture, and carrying out a step-by-step stirring reaction to obtain slurry; s6, aging, washing, dehydrating and drying the slurry to obtain a large-particle ternary precursor with high sphericity degree and low tap density; according to the preparation method, the high-nickel ternary precursor with high sphericity, low tap density and no cracking is obtained through the steps of firstly synthesizing the seed crystal and then carrying out grain growth, and adjusting condition parameters of each stage.

Description

Technical Field

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

[0002] With the rapid development of new energy vehicles, the requirements of the lithium battery industry are getting higher and higher. There are two main types of lithium batteries: lithium iron phosphate and ternary lithium batteries. Ternary lithium batteries have many advantages due to their higher energy density, greater power and stronger adaptability. Traditional ternary lithium batteries mainly refer to nickel-cobalt-manganese ternary lithium batteries. Due to the inheritance of batteries, any indicator of ternary precursor materials will affect the performance of the battery. Among them, sphericity and tap density are two key indicators for evaluating precursors.

[0003] During the synthesis process of nickel-cobalt-manganese ternary hydroxide, as the particle size increases and the particle consistency increases, the tap density increases, and cracks often appear on the surface of the secondary particles, and even broken balls appear, which seriously affects the subsequent sintering process of Li + The precipitation of ions will eventually affect the performance of lithium batteries. Therefore, it is difficult for ternary precursors to achieve 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 the ternary precursor from cracking and breaking due to its high sphericity. Summary of the invention

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

[0006] In order to achieve the above technical objectives, this application adopts the following technical solutions: In a first aspect, the present application provides a method for preparing a large-particle ternary precursor with high sphericity and low tap density, comprising the following steps: S1. N2 was introduced into the first reaction bottom solution at a pH of 11.4-11.7, and then the ternary solution and the regulating solution were simultaneously introduced to carry out a reaction to obtain a first slurry having a pH of 9.8-10.0; S2. adjusting the flow rate of the ternary solution and the regulating solution and passing them into the first slurry, performing a two-stage reaction, and obtaining a second slurry having a pH value of 9.3-9.8 and containing crystalline particles having a particle size D50 of 3.5-4.0 μm; S3. washing and dehydrating the second slurry to obtain seed crystals; S4. N2 was introduced into the second reaction solution at a pH of 10.3-10.6, and then seed crystals were added, heated and stirred to obtain a seed mixture; S5. The ternary solution and the regulating solution are introduced into the seed mixture, and a stepwise stirring reaction is performed to obtain a slurry having a pH value of 10.0-10.5 and containing crystalline particles having a particle size D50 of 13.0-15.0 μm; S6. The slurry is aged, washed, dehydrated and dried to obtain a large-particle ternary precursor with high sphericity and low tap density.

[0007] Preferably, the ternary solution includes 80-120 g / L NiSO4 solution, 80-120 g / L CoSO4 solution and 80-120 g / L MnSO4 solution; the regulating solution includes 10-20 wt% ammonia water and 20-40 wt% NaOH solution.

[0008] Preferably, in step S1, the ammonia concentration of the first reaction bottom solution is 2.0-6.0 g / L, and the N2 introduction rate is 1.0-4.0 m³ / h.

[0009] Preferably, in step S1, the flow rate of the ternary solution is 200-300 L / h, the flow rate of the ammonia water is 60-90 L / h, and the flow rate of the liquid alkali is 5-15 L / h; the temperature of the first reaction is 40-60°C, 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.

[0010] Preferably, in step S2, the flow rate of the ternary solution is 400-600 L / h, the flow rate of the ammonia water is 120-180 L / h, and the flow rate of the liquid alkali is 10-30 L / h; the temperature of the second stage reaction is 40-60°C, and the stirring rate is 150-300 r / min; the ammonia concentration in the second slurry is 2.0-6.0 g / L.

[0011] Preferably, in step S3, the solution used for washing is NaOH solution and pure water, and the water content of the seed crystal is 20-25%.

[0012] Preferably, in step S4, the second reaction base liquid includes ammonia water and pure water, the ammonia concentration of the second reaction base liquid is 5-8 g / L, the N2 inlet flow rate is 1.0-4.0 m³ / h; the temperature of the heating and stirring reaction is 40-60°C, and the solid content of the seed mixture is 5-15 g / L.

[0013] Preferably, the specific operations of step S5 are as follows: S51. The ternary solution, aqueous ammonia, and liquid caustic soda 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 perform a first-order stirring reaction to obtain a first slurry; S52. The ternary solution, aqueous ammonia and liquid caustic soda are adjusted to 300-350 L / h, 100-125 L / h and 15-25 L / h, respectively, and introduced into the first slurry for a second-order stirring reaction to obtain a second slurry; S53. The ternary solution, ammonia water and liquid alkali are adjusted to 450-500 L / h, 150-180 L / h and 20-30 L / h respectively and introduced into the second slurry for a third-order stirring reaction to obtain a slurry having a pH value of 10.0-10.5 and containing crystalline particles with a particle size D50 of 13.0-15.0 μm.

[0014] Preferably, the temperature of the first-order stirring reaction is 40-60°C, the stirring speed is 180-250r / min, the reaction time is 20-20.5h, the pH value of the first slurry is 10.0-10.5, and the ammonia concentration is 5.0-8.0g / L; the temperature of the second-order stirring reaction is 40-60°C, the stirring speed is 180-250r / min, the reaction time is 20-20.5h, the pH value of the second slurry is 10.0-10.5, and the ammonia concentration is 5.0-7.0g / L; the temperature of the third-order stirring reaction is 40-60°C, the stirring speed is 180-250r / min, the pH value of the second slurry is 10.0-10.5, and the ammonia concentration is 5.0-6.0g / L.

[0015] In a second aspect, the present application provides a large-particle ternary precursor with high sphericity and low tap density.

[0016] The beneficial effects of the present application are as follows: The present application obtains a high-nickel ternary precursor with high sphericity, low tap density and no cracking by first synthesizing seed crystals, then performing the steps of grain growth, and adjusting the condition parameters of each stage. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is the SEM image of the ternary precursor material obtained in Example 1. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0019] The present application provides a method for preparing a large-particle ternary precursor with high sphericity and low tap density, comprising the following steps: S1. N2 was introduced into the first reaction bottom solution at a pH of 11.4-11.7, and then the ternary solution and the regulating solution were simultaneously introduced to carry out a reaction to obtain a first slurry having a pH of 9.8-10.0; S2. adjusting the flow rate of the ternary solution and the regulating solution and passing them into the first slurry, performing a two-stage reaction, and obtaining a second slurry having a pH value of 9.3-9.8 and containing crystalline particles having a particle size D50 of 3.5-4.0 μm; S3. washing and dehydrating the second slurry to obtain seed crystals; S4. N2 was introduced into the second reaction solution at a pH of 10.3-10.6, and then seed crystals were added, heated and stirred to obtain a seed mixture; S5. The ternary solution and the regulating solution are introduced into the seed mixture, and a stepwise stirring reaction is performed to obtain a slurry having a pH value of 10.0-10.5 and containing crystalline particles having a particle size D50 of 13.0-15.0 μm; S6. The slurry is aged, washed, dehydrated and dried to obtain a large-particle ternary precursor with high sphericity and low tap density.

[0020] Preferably, the ternary solution includes 80-120 g / L NiSO4 solution, 80-120 g / L CoSO4 solution and 80-120 g / L MnSO4 solution; the regulating solution includes 10-20 wt% ammonia water and 20-40 wt% NaOH solution.

[0021] Preferably, in step S1, the ammonia concentration of the first reaction bottom solution is 2.0-6.0 g / L, and the N2 introduction rate is 1.0-4.0 m³ / h.

[0022] Preferably, in step S1, the flow rate of the ternary solution is 200-300 L / h, the flow rate of the ammonia water is 60-90 L / h, and the flow rate of the liquid alkali is 5-15 L / h; the temperature of the first reaction is 40-60°C, 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.

[0023] The pH value in one reaction stage is high, and its purpose is to reduce the starting particle size to prevent the starting particle size from being too large and failing to meet the requirements of crystal seed morphology, sphericity and other indicators; the rotation speed in one reaction stage is high, and its purpose is to control the starting particle size and sphericity; the flow rate of the metal solution in one reaction stage is small, and its purpose is to reduce the number of starting particles, which is conducive to subsequent rapid growth, thereby avoiding the influence of the reaction time process on other indicators.

[0024] Preferably, in step S2, the flow rate of the ternary solution is 400-600 L / h, the flow rate of the ammonia water is 120-180 L / h, and the flow rate of the liquid alkali is 10-30 L / h; the temperature of the second stage reaction is 40-60°C, and the stirring rate is 150-300 r / min; the ammonia concentration in the second slurry is 2.0-6.0 g / L.

[0025] Controlling the ammonia concentration within the target range in the first-stage reaction and the second-stage reaction is conducive to obtaining particles with rich internal porosity and fine surface morphology, so as to reduce the tap density of the seed crystal and increase the capacity of the subsequent sintered positive electrode material.

[0026] During the second-stage reaction, controlling the pH value within the target range is beneficial to controlling the seed crystal morphology, growth rate and tap density. Within the target rotation speed, it has little effect on the tap density of the final product and is beneficial to improving the sphericity. Within the metal solution flow rate range specified in this application, it is beneficial to promote the growth of seed crystal particles.

[0027] Preferably, in step S3, the solution used for washing is NaOH solution and pure water, and the water content of the seed crystal is 20-25%.

[0028] In the present application, steps S1-S3 are the seed synthesis stage, and steps S4-S6 are the particle growth stage.

[0029] Preferably, in step S4, the second reaction base liquid includes ammonia water and pure water, the ammonia concentration of the second reaction base liquid is 5-8 g / L, the N2 inlet flow rate is 1.0-4.0 m³ / h; the temperature of the heating and stirring reaction is 40-60°C, and the solid content of the seed mixture is 5-15 g / L.

[0030] Preferably, the specific operations of step S5 are as follows: S51. The ternary solution, aqueous ammonia, and liquid caustic soda 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 perform a first-order stirring reaction to obtain a first slurry; S52. The ternary solution, aqueous ammonia and liquid caustic soda are adjusted to 300-350 L / h, 100-125 L / h and 15-25 L / h, respectively, and introduced into the first slurry for a second-order stirring reaction to obtain a second slurry; S53. The ternary solution, ammonia water and liquid alkali are adjusted to 450-500 L / h, 150-180 L / h and 20-30 L / h respectively and introduced into the second slurry for a third-order stirring reaction to obtain a slurry having a pH value of 10.0-10.5 and containing crystalline particles with a particle size D50 of 13.0-15.0 μm.

[0031] Preferably, the temperature of the first-order stirring reaction is 40-60°C, the stirring speed is 180-250r / min, the reaction time is 20-20.5h, the pH value of the first slurry is 10.0-10.5, and the ammonia concentration is 5.0-8.0g / L; the temperature of the second-order stirring reaction is 40-60°C, the stirring speed is 180-250r / min, the reaction time is 20-20.5h, the pH value of the second slurry is 10.0-10.5, and the ammonia concentration is 5.0-7.0g / L; the temperature of the third-order stirring reaction is 40-60°C, the stirring speed is 180-250r / min, the pH value of the second slurry is 10.0-10.5, and the ammonia concentration is 5.0-6.0g / L.

[0032] 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.

[0033] During steps S4-S6, the ammonia concentration of the first slurry is within a limited range to control the size of the start-up particle size; during the second-order stirring reaction and the third-order stirring reaction, as the flow rate of the metal solution increases, it will have a certain impact on the tap density, and the ammonia concentration is controlled to avoid the increase in the tap density and the change in surface morphology. During steps S4-S6, the adjustment of the ammonia concentration is conducive to obtaining particles with a slender morphology and many pores.

[0034] During steps S4-S6, the rotation speed of the first-order stirring reaction is within a limited range, which is beneficial to regulating the startup particle size and sphericity and preventing agglomeration; the rotation speed of the second-order stirring reaction and the third-order stirring reaction is controlled within a limited range, which is beneficial to controlling the sphericity, tap density and growth rate of the particles.

[0035] During steps S4-S6, in the first-order 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 newly started; in the second-order stirring reaction and the third-order stirring reaction, the flow rate of the ternary liquid is within a limited range, which is beneficial to increase the growth rate; in order to avoid sudden changes in the conditions of the stirring reaction and the impact on the sphericity, the present application increases the flow rate of the ternary liquid in stages (second-order stirring reaction, third-order stirring reaction).

[0036] The present application provides a large-particle ternary precursor with high sphericity and low tap density.

[0037] The present solution is further described below through specific embodiments.

[0038] Source of raw materials Ternary solution: includes 100g / L NiSO4 aqueous solution, 100g / L CoSO4 aqueous solution, and 100g / L MnSO4 aqueous solution.

[0039] Example 1 A method for preparing a large-particle ternary precursor with high sphericity and low tap density comprises the following steps: S1. To 12m 3 Add 6m 3 30wt% pure water, 30wt% NaOH solution and 16wt% ammonia water were added, stirred, heated to 55°C, and 2.0m³ / h of N2 were introduced to obtain a first reaction bottom liquid with a pH value of 11.6 and an ammonia concentration of 3.5g / L; within 0-10h, the ternary solution, ammonia water and liquid alkali were added into the kettle at a flow rate of 200L / h, 65L / h and 6L / h respectively, the rotation speed was controlled to 300r / min, the pH value was controlled to drop to 9.9 and the ammonia concentration was 4.0g / L, and the first reaction was completed to obtain a first slurry; S2. The ternary solution, ammonia water and liquid caustic soda were adjusted to 400 L / h, 125 L / h and 10 L / h, respectively, the pH value of the slurry in the reactor was controlled to drop to 9.5, the ammonia concentration was 4.0 g / L, the speed was controlled to 200 r / min, and the addition reaction was stopped after the crystal particles grew continuously until D50 was 4.0 μm, and the second stage reaction was completed to obtain the second slurry; S3. The second slurry was washed with NaOH solution and hot pure water and dehydrated to obtain a washed semi-finished product having a water content of 20%, which is the seed crystal; S4. at 12m 3 Pure water and ammonia solution are added to the reactor as the second reaction bottom liquid, the pH value of the second reaction bottom liquid is 10.5, and the ammonia concentration is 7.0 g / L, and then the seed crystal is put into the reactor, and the solid content of the slurry is adjusted to 10 g / L, the slurry in the reactor is heated to 55°C, and 3.0 m³ / h of N2 is introduced, and the rotation speed is set to 250 r / min to obtain a seed crystal mixture; S5. Within 0-20h, the ternary solution, ammonia water, and liquid caustic soda are introduced into the seed mixture at flow rates of 200L / h, 65L / h, and 15L / h, respectively, and the pH value of the slurry in the reactor is controlled to be reduced to 10.1, the ammonia concentration is reduced to 6.0g / L, and the rotation speed is reduced to 180r / min. Other conditions remain unchanged as in step S4. After the first-order stirring reaction is completed, a first slurry is obtained; within 20-40h, the ternary solution, ammonia water, and liquid caustic soda are adjusted to 350L / h, 122L / h, and 25L / h, respectively, and introduced into the first slurry, and the pH value of the slurry in the reactor is controlled to be 10.1, the ammonia concentration is 5.5g / L, the speed is controlled at 180r / min, and other conditions remain unchanged as in step S4. After the second-order stirring reaction is completed, a second slurry is obtained; the ternary solution, ammonia water, and liquid alkali are adjusted to 500L / h, 175L / h, and 25L / h respectively and introduced into the second slurry, the pH value of the slurry in the reactor is controlled to be 10.0, the ammonia concentration is 5.0g / L, and the speed is controlled at 160r / min. After the crystal particles continue to grow to a particle size D50 of 14.0μm, the feeding is stopped. After the third-order stirring reaction is completed, a slurry containing crystal particles is obtained; S6. The slurry is aged, washed, dehydrated and dried to obtain a large-particle ternary precursor with high sphericity and low tap density.

[0040] Example 2 A method for preparing a large-particle ternary precursor with high sphericity and low tap density comprises the following steps: S1. To 12m 3 Add 6m 3 30wt% pure water, 30wt% NaOH solution and 16wt% ammonia water were added, stirred, heated to 55°C, and 2.0m³ / h of N2 were introduced to obtain a first reaction bottom liquid with a pH value of 11.4 and an ammonia concentration of 6g / L; within 0-10h, the ternary solution, ammonia water and liquid alkali were added into the kettle at a flow rate of 300L / h, 90L / h and 15L / h respectively, the rotation speed was controlled to 250r / min, the pH value was controlled to drop to 9.8 and the ammonia concentration was 3.0g / L, and the first reaction was completed to obtain a first slurry; S2. The ternary solution, ammonia water and liquid caustic soda were adjusted to 600 L / h, 180 L / h and 30 L / h respectively, the pH value of the slurry in the reactor was controlled to be reduced to 9.3, the ammonia concentration was 3.0 g / L, the speed was controlled to be 200 r / min, and the addition reaction was stopped after the crystal particles grew continuously until the D50 was 4.0 μm, and the second stage reaction was completed to obtain the second slurry; S3. The second slurry was washed with NaOH solution and hot pure water and dehydrated to obtain a washed semi-finished product having a water content of 20%, which is the seed crystal; S4. at 12m 3Pure water and ammonia solution are added to the reactor as the second reaction bottom liquid, the pH value of the second reaction bottom liquid is 10.5, and the ammonia concentration is 8.0 g / L, and then the seed crystal is put into the reactor, and the solid content of the slurry is adjusted to 10 g / L, the slurry in the reactor is heated to 55°C, and 3.0 m³ / h of N2 is introduced to obtain a seed crystal mixture; S5. Within 0-20h, the ternary solution, ammonia water, and liquid caustic soda are introduced into the seed mixture at flow rates of 150L / h, 70L / h, and 10L / h, respectively, and the pH value of the slurry in the reactor is controlled to be reduced to 10.1, the ammonia concentration is reduced to 6.0g / L, and the rotation speed is reduced to 180r / min. Other conditions remain unchanged as in step S4. After the first-order stirring reaction is completed, a first slurry is obtained; within 20-40h, the ternary solution, ammonia water, and liquid caustic soda are adjusted to 300L / h, 100L / h, and 15L / h, respectively, and introduced into the first slurry, and the pH value of the slurry in the reactor is controlled to be 10.1, the ammonia concentration is 5.5g / L, the speed is controlled at 180r / min, and other conditions remain unchanged as in step S4. After the second-order stirring reaction is completed, a second slurry is obtained; the ternary solution, ammonia water, and liquid alkali are adjusted to 450L / h, 150L / h, and 30L / h respectively and introduced into the second slurry, the pH value of the slurry in the reactor is controlled to be 10.2, the ammonia concentration is 5.0g / L, and the speed is controlled at 160r / min. After the crystal particles continue to grow to a particle size D50 of 14.0μm, the feeding is stopped. After the third-order stirring reaction is completed, a slurry containing crystal particles is obtained; S6. The slurry is aged, washed, dehydrated and dried to obtain a large-particle ternary precursor with high sphericity and low tap density.

[0041] Comparative Example 1 A method for preparing a large-particle ternary precursor, the other contents of which are the same as those of Example 1, except that the flow rates of the ternary solution, ammonia water, and liquid alkali in step S5 remain unchanged.

[0042] Comparative Example 2 A method for preparing a ternary precursor comprises the following steps: S1. To 12m 3 Add 6m 3 30wt% pure water, 30wt% NaOH solution and 16wt% ammonia water were added, stirred, heated to 55℃, and 2.0m³ / h N 2 , obtaining a first reaction bottom liquid with a pH value of 11.7 and an ammonia concentration of 3.5 g / L; within 0-10 hours, adding the ternary solution, ammonia water and liquid alkali into the kettle at a flow rate of 200 L / h, 65 L / h and 6 L / h respectively, controlling the rotation speed to 250 r / min, controlling the pH value to 9.8 and the ammonia concentration to 6.0 g / L, completing the first reaction, obtaining a first slurry; S2. The ternary solution, ammonia water and liquid caustic soda were adjusted to 400 L / h, 125 L / h and 10 L / h, respectively, the pH value of the slurry in the reactor was controlled to drop to 9.3, the ammonia concentration was 3.0 g / L, the speed was controlled to 200 r / min, and the addition reaction was stopped after the crystal particles grew continuously until D50 was 4.0 μm, and the second stage reaction was completed to obtain the second slurry; S3. The ternary solution, ammonia water, and liquid caustic soda are introduced into the second slurry at flow rates of 200 L / h, 65 L / h, and 15 L / h, respectively, and the pH value of the slurry in the reactor is controlled to be reduced to 10.1, the ammonia concentration is reduced to 6.0 g / L, and the speed is reduced to 180 r / min. After the crystal particles continue to grow to a particle size D50 of 14.0 μm, the feeding is stopped. After the third-order stirring reaction is completed, a slurry containing crystal particles is obtained; S4. The slurry is aged, washed, dehydrated and dried to obtain a large-particle ternary precursor with high sphericity and low tap density.

[0043] Test and Evaluation The ternary precursor obtained in Example 1 was examined by electron microscopy at 5000 times magnification, and the results were as follows: Figure 1 As shown, it can be seen that the ternary precursor obtained in the present application has high sphericity, low tap density and no cracks.

[0044] The tap density of the ternary precursors obtained in Example 1-2 and Comparative Example 1-2 was tested, and the results are shown in Table 1.

[0045] Table 1 Tap density test results

[0046] The present application obtains a high-nickel ternary precursor with high sphericity, low tap density and no cracking by first synthesizing seed crystals, then performing the steps of grain growth, and adjusting the condition parameters of each stage.

[0047] The above are only preferred specific implementations of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope 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: The following steps are involved: S1. In the first reaction bottom liquid with a pH value of 11.4-11.7, N2 is introduced, and then the ternary solution and the regulating solution are simultaneously introduced to carry out a reaction to obtain a first slurry with a pH value of 9.8-10.0; S2. adjusting the flow rate of the ternary solution and the regulating solution and passing them into the first slurry to perform a two-stage reaction to obtain a second slurry having a pH value of 9.3-9.8 and containing crystalline particles with a particle size D50 of 3.5-4.0 μm; S3. washing and dehydrating the second slurry to obtain seed crystals; S4. N2 was introduced into the second reaction solution at a pH of 10.3-10.6, and then seed crystals were added, heated and stirred to obtain a seed mixture; S5. The ternary solution and the regulating solution are introduced into the seed mixture, and a stepwise stirring reaction is performed to obtain a slurry having a pH value of 10.0-10.5 and containing crystalline particles having 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.

2. The method for preparing a large-particle ternary precursor with high sphericity and low tap density according to claim 1, characterized in that: The ternary solution includes 80-120 g / L NiSO4 solution, 80-120 g / L CoSO4 solution and 80-120 g / L MnSO4 solution; the regulating solution includes 10-20 wt% ammonia water and 20-40 wt% NaOH solution.

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

4. The method for preparing a large-particle ternary precursor with high sphericity and low tap density according to claim 2, characterized in that: In step S1, the flow rate of the ternary solution is 200-300 L / h, the flow rate of the ammonia water is 60-90 L / h, and the flow rate of the liquid alkali is 5-15 L / h; the temperature of the first stage reaction is 40-60°C, 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.

5. The method for preparing a large-particle ternary precursor with high sphericity and low tap density according to claim 2, characterized in that: In step S2, the flow rate of the ternary solution is 400-600 L / h, the flow rate of the ammonia water is 120-180 L / h, and the flow rate of the liquid alkali is 10-30 L / h; the temperature of the second stage reaction is 40-60°C, and the stirring rate is 150-300 r / min; the ammonia concentration in the second slurry is 2.0-6.0 g / L.

6. The method for preparing a large-particle ternary precursor with high sphericity and low tap density according to claim 2, 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%.

7. The method for preparing a large-particle ternary precursor with high sphericity and low tap density according to claim 2, characterized in that: In step S4, the second reaction base liquid includes ammonia water and pure water, the ammonia concentration of the second reaction base liquid is 5-8g / L, the N2 introduction flow rate is 1.0-4.0m³ / h; the temperature of the heating and stirring reaction is 40-60°C, and the solid content of the seed mixture is 5-15g / L.

8. The method for preparing a large-particle ternary precursor with high sphericity and low tap density according to claim 2, characterized in that: The specific operations of step S5 are as follows: S51. The ternary solution, aqueous ammonia, and liquid caustic soda 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 perform a first-order stirring reaction to obtain a first slurry; S52. The ternary solution, ammonia water and liquid caustic soda are adjusted to 300-350 L / h, 100-125 L / h and 15-25 L / h, respectively, and introduced into the first slurry to perform a second-order stirring reaction to obtain a second slurry; S53. The ternary solution, ammonia water and liquid alkali are adjusted to 450-500 L / h, 150-180 L / h and 20-30 L / h respectively and introduced into the second slurry to carry out a third-order stirring reaction to obtain a slurry having a pH value of 10.0-10.5 and containing crystalline particles with a particle size D50 of 13.0-15.0 μm.

9. The method for preparing a large-particle ternary precursor with high sphericity and low tap density according to claim 8, characterized in that: The temperature of the first-order stirring reaction is 40-60°C, the stirring speed is 180-250r / min, the reaction time is 20-20.5h, the pH value of the first slurry is 10.0-10.5, and the ammonia concentration is 5.0-8.0g / L; the temperature of the second-order stirring reaction is 40-60°C, the stirring speed is 180-250r / min, the reaction time is 20-20.5h, the pH value of the second slurry is 10.0-10.5, and the ammonia concentration is 5.0-7.0g / L; the temperature of the third-order stirring reaction is 40-60°C, the stirring speed is 180-250r / min, the pH value of the second slurry is 10.0-10.5, and the ammonia concentration is 5.0-6.0g / L.

10. A large-particle ternary precursor with high sphericity and low tap density obtained by the preparation method according to any one of claims 1 to 9.

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