High-nickel large-particle ternary precursor and its preparation method

Abstract

This invention provides a high-nickel large-particle ternary precursor and its preparation method. It comprises multiple secondary particles, each composed of multiple primary particles, with multiple pores existing between the primary particles. The chemical formula of the high-nickel large-particle ternary precursor is Ni. x Co y Mn z (OH)2, where x+y+z=1, and 0.9≤x≤1.0, 0≤y≤0.1, 0≤z≤0.1; the D50 particle size of the high-nickel large-particle ternary precursor is 10~16 μm; the equivalent circle diameter of the pores between primary particles is A, the thickness of the primary particles is B, A / (A+B)>0.45, and the average value of the equivalent circle diameter corresponding to each pore is the equivalent circle diameter of the pores between primary particles. The above technical solution solves the problem of easy cracking in the existing high-nickel large-particle ternary precursor.

Description

Technical Field

[0001] This invention belongs to the field of preparation technology of large ternary precursor particles, specifically, it relates to a high-nickel large-particle ternary precursor and its preparation method. Background Technology

[0002] In the preparation of large ternary precursor particles, cracking intensifies with increasing nickel content and particle size. This not only affects product yield but also reduces production efficiency, becoming a major industry challenge hindering the development of high-nickel large particles. Currently, the industry primarily employs the following two methods to address this issue:

[0003] (1) Aging and Restoration Method

[0004] After the particle size meets the standard and the machine is shut down, an aging process is carried out by adding alkali and raising the temperature. The aging time is usually 10 to 40 hours. Although this method can repair surface cracks, deep cracks may still exist, and it will significantly reduce production efficiency.

[0005] (2) Additive method

[0006] Additives are added during the synthesis process to reduce particle collisions, thereby lowering the risk of cracking. However, this method increases production costs because the use of additives increases the input of raw materials.

[0007] In summary, current methods still have limitations in preventing or repairing cracking in high-nickel large-particle ternary precursors. Further research and development of more efficient and low-cost solutions are needed to address the cracking problem at its root and promote the widespread application of high-nickel large-particle ternary precursors. Summary of the Invention

[0008] The main objective of this invention is to provide a high-nickel large-particle ternary precursor and its preparation method, so as to solve the problem that existing high-nickel large-particle ternary precursors are prone to cracking.

[0009] To achieve the above objectives, in one aspect, the present invention provides a high-nickel large-particle ternary precursor, comprising multiple secondary particles, wherein the secondary particles are composed of multiple primary particles, and multiple pores exist between the primary particles. The chemical formula of the high-nickel large-particle ternary precursor is Ni. x Co y Mn z (OH)2, where x+y+z=1, and 0.9≤x≤1.0, 0≤y≤0.1, 0≤z≤0.1; the D50 particle size of the high-nickel large-particle ternary precursor is 10~16 μm; the equivalent circle diameter of the pores between primary particles is A, the thickness of the primary particles is B, A / (A+B)>0.45, and the average value of the equivalent circle diameter corresponding to each pore is the equivalent circle diameter of the pores between primary particles.

[0010] Furthermore, A / (A+B) is 0.46~0.55.

[0011] In another aspect, the present invention provides a method for preparing the aforementioned high-nickel large-particle ternary precursor, the method comprising: step S1, preparing a metal liquid by mixing soluble nickel salt, soluble cobalt salt, soluble manganese salt, and pure water according to the proportions of each element in the chemical formula of the high-nickel large-particle ternary precursor; step S2, mixing raw materials including a first precipitant solution, a first complexing agent solution, ammonia water, and water under a nitrogen atmosphere to obtain a reaction base liquid; and step S3, passing the metal liquid, a second precipitant solution, and a second complexing agent solution into the reaction base liquid under a nitrogen atmosphere to perform a co-precipitation reaction to obtain secondary precursor particles, wherein the D50 particle size of the secondary precursor particles grows to 10~16. When the particle size reaches μm, the feeding is stopped to obtain a crude high-nickel large-particle ternary precursor; in step S4, the crude high-nickel large-particle ternary precursor is washed, dried, sieved, and iron removed in sequence to obtain a high-nickel large-particle ternary precursor; wherein, the primary particles in the secondary particles of the precursor satisfy A / (A+B)>0.45.

[0012] Furthermore, in step S1 above, the total molar concentration of metal ions in the metal liquid is 1~2.5 mol / L.

[0013] Furthermore, in step S2 above, the pH value of the reaction substrate is 10.7~11.7, and the molar concentration of ammonia in the reaction substrate is 0.06~0.2950 mol / L.

[0014] Furthermore, in step S2, the stirring speed is 100~500 r / min; and / or the volume of water is 70~150L; and / or the temperature of the reaction substrate is 50~75℃.

[0015] Furthermore, in step S3, the flow rates of the molten metal, the second precipitant solution, and the second complexing agent solution gradually increase with the increase of reaction time; and / or the flow rate of the molten metal is 8.5~26 L / h.

[0016] Furthermore, in step S3, the coprecipitation reaction is stirred, and the stirring speed gradually decreases as the reaction time increases. The initial stirring speed is 400~550 rpm. When the D50 particle size of the precursor secondary particles grows to 3~5 μm, the stirring speed gradually decreases in the range of 450~120 rpm.

[0017] Furthermore, in step S4, the drying temperature is 120~130℃, and the drying time is 1~8h.

[0018] Furthermore, in step S4, the water content of the washed high-nickel large-particle ternary precursor crude product is <5000 ppm.

[0019] Applying the technical solution of this application, in the structural design of the high-nickel large-particle ternary precursor, the ratio of the equivalent circle diameter of the pores between primary particles to the thickness of the primary particles is controlled at A / (A+B) > 0.45. This technical feature plays a key role in the overall technical solution. By controlling the pores between primary particles, stress concentration during crystal growth caused by high nickel content and large particle size can be effectively dispersed and alleviated. This design principle effectively solves the technical problem of easy cracking in the synthesis of high-nickel large-particle ternary precursors in the prior art. Due to the existence of pores, the stress between particles is effectively released, and secondary particles will not crack as the particle size gradually increases, fundamentally solving the problem limiting the development of high-nickel large particles. Even under conditions of high nickel content and large particle size, crack generation can be avoided, thereby improving the product qualification rate and production efficiency, and enhancing the stability of the material structure. In summary, the technical solution created by this invention not only solves the cracking problem of high-nickel large-particle ternary precursors, but also improves production efficiency and economic benefits, which is of great significance for promoting the widespread application of high-nickel cathode materials. Attached Figure Description

[0020] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0021] Figure 1 Images (a) and (b) in this paper show scanning electron microscope (SEM) images of the high-nickel large-particle ternary precursor in Example 1 of this application at different magnifications.

[0022] Figure 2 Images (a) and (b) in this paper show scanning electron microscope (SEM) images of the high-nickel large-particle ternary precursor in Example 2 of this application at different magnifications.

[0023] Figure 3 (a) and (b) in the figure show scanning electron microscope images of the high-nickel large-particle ternary precursor in Comparative Example 1 of this application at different magnifications. Detailed Implementation

[0024] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the embodiments.

[0025] As described in the background section, existing high-nickel large-particle ternary precursors are prone to cracking. To address this problem, this application provides a high-nickel large-particle ternary precursor comprising multiple secondary particles, each composed of multiple primary particles, with multiple pores existing between the primary particles. The chemical formula of the high-nickel large-particle ternary precursor is Ni. x Co y Mn z (OH)2, where x+y+z=1, and 0.9≤x≤1.0, 0≤y≤0.1, 0≤z≤0.1; the D50 particle size of the high-nickel large-particle ternary precursor is 10~16 μm; the equivalent circle diameter of the pores between primary particles is A, the thickness of the primary particles is B, A / (A+B)>0.45, and the average value of the equivalent circle diameter corresponding to each pore is the equivalent circle diameter of the pores between primary particles.

[0026] In the structural design of the high-nickel large-particle ternary precursor, this application controls the ratio of the equivalent circle diameter of the pores between primary particles to the thickness of the primary particles to be A / (A+B) > 0.45. This technical feature plays a crucial role in the overall technical solution. By controlling the porosity between primary particles, stress concentration during crystal growth caused by high nickel content and large particle size can be effectively dispersed and alleviated. This design principle effectively solves the technical problem of easy cracking in the synthesis of high-nickel large-particle ternary precursors in the prior art. Due to the existence of pores, the stress between particles is effectively released, and secondary particles will not crack as the particle size gradually increases. This fundamentally solves the problem limiting the development of high-nickel large particles. Even under conditions of high nickel content and large particle size, crack generation can be avoided, thereby improving the product qualification rate and production efficiency, and enhancing the stability of the material structure. In summary, the technical solution created by this invention not only solves the cracking problem of high-nickel large-particle ternary precursors but also improves production efficiency and economic benefits, which is of great significance for promoting the widespread application of high-nickel cathode materials.

[0027] In this application, the test method for the equivalent circle diameter A of the pores is as follows: using FIJI ImageJ software, the pore regions formed between primary particles are identified and their equivalent circle areas are measured; the calculation method is as follows: based on the geometric relationship, the equivalent circle area is converted from the measured area, i.e., A=2×(equivalent circle area / π)^(1 / 2), and then the statistical average of multiple equivalent circle diameters A is used as the final result.

[0028] The thickness B of a primary particle refers to the shortest distance between all its tangent parallel lines. The test method is to measure the thickness of the selected primary particle in the microscopic image using FIJI ImageJ software. The calculation method is to directly read the linear distance value measured by the software and then use the statistical average of the thickness B of multiple particles as the final result.

[0029] In some embodiments, A / (A+B) is 0.46 to 0.55.

[0030] By precisely controlling A / (A+B) within the above range, it is beneficial to manage the internal stress of secondary particles formed by primary particle stacking, reducing the risk of cracking under conditions of high nickel content and large particle size. This structural optimization allows the balance between primary particles and pores to reach a new level during the growth process, improving the integrity and consistency of the material.

[0031] In another typical embodiment of this application, a method for preparing the aforementioned high-nickel large-particle ternary precursor is provided. This method includes: Step S1, preparing a metal liquid by mixing soluble nickel salt, soluble cobalt salt, soluble manganese salt, and pure water according to the proportions of the elements in the chemical formula of the high-nickel large-particle ternary precursor; Step S2, stirring and mixing raw materials including a first precipitant solution, a first complexing agent solution, ammonia water, and water in a nitrogen atmosphere to obtain a reaction base liquid; Step S3, mixing the metal liquid in a nitrogen atmosphere... A second precipitant solution and a second complexing agent solution are introduced into the reaction substrate to carry out a co-precipitation reaction, thereby obtaining secondary precursor particles. When the D50 particle size of the secondary precursor particles grows to 10~16μm, the feeding is stopped, and a crude high-nickel large-particle ternary precursor is obtained. In step S4, the crude high-nickel large-particle ternary precursor is washed, dried, sieved, and iron removed sequentially to obtain the high-nickel large-particle ternary precursor. The primary particles in the secondary precursor particles satisfy A / (A+B)>0.45.

[0032] The core of the above preparation method lies in controlling the equivalent circle diameter A of the pores between primary particles and the thickness B of the primary particles to satisfy A / (A+B) > 0.45. This fundamentally avoids the problem of secondary particle cracking during the preparation of ternary precursors with a particle size distribution D50 of 10~16 μm. Specifically, by precisely controlling key parameters such as pH, ammonia value, molten metal flow rate, and stirring rate, the orderly growth of the primary particles in the precursor is promoted, effectively releasing the stress between particles and preventing cracking. This eliminates the need for subsequent time-consuming aging processes to repair cracks, reduces the uncertainty of alkali addition, improves production efficiency, and lowers costs. More importantly, this method uses zero additives throughout the process, reducing not only raw material input costs but also the mother liquor purification steps, which is conducive to clean production and environmental protection. The resulting high-nickel, large-particle ternary precursor has a high production qualification rate and better structural stability, meeting the economic requirements of high production capacity and low cost, and significantly enhancing the company's core competitiveness in the global high-nickel cathode material field.

[0033] It should be noted that the first precipitant solution and the second precipitant solution may be the same or different, preferably the same, and more preferably, both the first precipitant solution and the second precipitant solution are sodium hydroxide precipitant solutions. The first complexing agent solution and the second complexing agent solution may be introduced into the reaction in the same or different ways, preferably the same, and more preferably, both the first complexing agent solution and the second complexing agent solution are ammonia complexing agent solutions.

[0034] In some embodiments, in step S1, the total molar concentration of metal ions in the molten metal is 1~2.5 mol / L.

[0035] By controlling the total molar concentration of metal ions in the molten metal within the above range, the uniformity and stability of the initial stage of particle formation are improved, the risk of abnormal crystallization caused by local oversaturation is reduced, thereby reducing the excessive accumulation of internal stress and cracking risk of particles, and improving the product qualification rate and production efficiency.

[0036] In some embodiments, in step S2, the pH value of the reaction substrate is 10.7~11.7, and the molar concentration of ammonia in the reaction substrate is 0.06~0.2950 mol / L.

[0037] By precisely controlling the pH value and ammonia molar concentration of the reaction substrate within the above range, the suitability of the synthesis environment was improved, promoting the uniform growth of primary particles and reducing the formation of cracks inside and on the surface of the particles.

[0038] In some embodiments, in step S2, the stirring speed is 100~500 r / min; and / or the volume of water is 70~150 L; and / or the temperature of the reaction substrate is 50~75°C.

[0039] By controlling the temperature of the reaction substrate, the stirring speed, and the volume of water within the above ranges, the reaction kinetics were effectively managed, ensuring that the equivalent circle diameter of the pores between primary particles and the thickness of the primary particles satisfied A / (A+B)>0.45.

[0040] In some embodiments, in step S3, the flow rates of the molten metal, the second precipitant solution, and the second complexing agent solution gradually increase with increasing reaction time; and / or the flow rate of the molten metal is 8.5~26 L / h.

[0041] The preferred flow rates of the molten metal, the second precipitant solution, and the second complexing agent solution gradually increase with increasing reaction time. This strategy provides appropriate material input rates for different stages of cathode material precursor growth, reduces the risk of rapid crystallization caused by local supersaturation, reduces internal stress, and thus reduces the risk of cracking. Optimizing the molten metal flow rate within the above range helps to balance reaction rate and efficiency.

[0042] In some embodiments, during step S3, the coprecipitation reaction is stirred, and the stirring speed gradually decreases as the reaction time increases. The initial stirring speed is 400~550 rpm, and when the D50 particle size of the precursor secondary particles grows to 3~5 μm, the stirring speed gradually decreases in the range of 450~120 rpm.

[0043] In step S3, the initial stirring speed is set within the aforementioned range, and the stirring speed is gradually reduced as the reaction time increases. This strategy involves adjusting the stirring speed within the range of 450–120 rpm when the D50 particle size of the primary particles in the current driving medium grows to 3–5 μm. Gradually reducing the stirring speed helps control the formation of pores between primary particles, thereby optimizing the particle structure.

[0044] In some embodiments, in step S4, the drying temperature is preferably controlled at 120~130°C, and the drying time is 1~8 hours. This helps to control the residual moisture content within a controllable range.

[0045] In some embodiments, in step S4, it is preferable to control the moisture content of the crude high-nickel large-particle ternary precursor after washing to be <5000 ppm, which helps to further reduce the risk of thermal stress cracking in subsequent processing caused by residual moisture.

[0046] The present application will be further described in detail below with reference to specific embodiments, which should not be construed as limiting the scope of protection claimed in the present application.

[0047] Example 1

[0048] Ni with a particle size distribution D50 of 12 μm was prepared. 0.91 Co0.045 Mn 0.045 The (OH)2 ternary material precursor has an equivalent circle diameter of pores between primary particles of A and a thickness of primary particles of B, with A / (A+B)=0.46.

[0049] S1: A ternary mixed salt aqueous solution with a total metal ion concentration of 2.3 mol / L was prepared by mixing soluble salts of nickel, cobalt, and manganese with pure water at a target molar ratio. The chemical formula of the precursor material is: Ni 0.91 Co 0.045 Mn 0.045 (OH)2; Prepare a sodium hydroxide precipitant solution with a concentration of 8 mol / L and an ammonia complexing agent solution with a concentration of 5.1 mol / L;

[0050] S2: Add pure water, complexing agent solution, and precipitant solution to the reactor, and purge with nitrogen for protection. The amount of pure water added is 60 L, and a reaction base solution with a pH of 11.85 and an ammonia content of 0.18 mol / L is prepared. The reactor temperature is 55℃, and the reactor stirring speed is 480 r / min.

[0051] S3: The molten metal, precipitant, and complexing agent from S1 are introduced into the bottom liquid of step S2 for co-precipitation reaction, and nitrogen gas is continuously introduced for protection. The flow rate of molten metal is 2 L / h. After 4 h of synthesis, the flow rate of molten metal is increased to 22 L / h (rate 2.5 L / h). After 0.33 h of nucleation, the pH drops from 11.85 to 11.40. When the particle size D50 reaches 5 μm, the feed is stopped and the sample is transferred to the seed tank.

[0052] S4: Add pure water, complexing agent solution, and precipitant solution to the reactor, and purge with nitrogen for protection. The amount of pure water added is 140 L, and a reaction base solution with a pH of 11.40 and an ammonia content of 0.25 mol / L is prepared. The reactor temperature is 55℃, and the reactor stirring speed is 400 r / min.

[0053] S5: Transfer the seed crystals prepared in S3, with a dry weight of 4.0 kg, into the bottom solution of S4;

[0054] S6: The molten metal, precipitant and complexing agent from S1 are introduced into the bottom liquid of step S5 for co-precipitation reaction, and nitrogen gas is continuously introduced for protection. The molten metal flow rate is 5 L / h. After 1 h of synthesis, the molten metal flow rate is increased to 20 L / h (rate 0.75 L / h). The rotation speed is set in the range of 400~120 rpm and gradually decreased (rate 14 rpm / h).

[0055] S7: According to S6, when the particle size grows to 12 μm, stop feeding and the particles will not crack.

[0056] S8: According to S7, the slurry from the shutdown process is rinsed and dehydrated with pure water at 75℃. The washed material obtained after dehydration is dried in an oven at 120℃ until H2O < 5000 ppm, then cooled to room temperature. The dried material is then sieved through a 325-mesh vibrating screen to remove iron and packaged to obtain nickel-cobalt-manganese ternary precursors with a particle size of 12 μm. Scanning electron microscope images at different magnifications are shown below. Figure 1 As shown, from Figure 1 It can be seen that it does not crack.

[0057] Example 2

[0058] Ni with a particle size distribution D50 of 14.0 μm was prepared. 0.90 Co 0.05 Mn 0.05 The (OH)2 ternary material precursor has an equivalent circle diameter of pores between primary particles of A and a thickness of primary particles of B, with A / (A+B)=0.51.

[0059] S1: A ternary mixed salt aqueous solution with a total metal ion concentration of 2.3 mol / L was prepared by mixing soluble salts of nickel, cobalt, and manganese with pure water at a target molar ratio. The chemical formula of the precursor material is: Ni 0.90 Co 0.05 Mn 0.05 (OH)2; Prepare a sodium hydroxide precipitant solution with a concentration of 8 mol / L and an ammonia complexing agent solution with a concentration of 5.1 mol / L;

[0060] S2: Add pure water, complexing agent solution, and precipitant solution to the reactor, and purge with nitrogen for protection. The amount of pure water added is 100 L, and a reaction base solution with a pH of 12.25 and an ammonia content of 0.12 mol / L is prepared. The reactor temperature is 50℃, and the stirring speed is 450 r / min.

[0061] S3: The molten metal, precipitant, and complexing agent from S1 are introduced into the bottom solution from step S2 for co-precipitation reaction, with continuous nitrogen protection. Nucleation occurs for 1.5 h, the pH decreases from 12.25 to 11.15, the molten metal flow rate is 8.5~26 L / h (15 h ramp), and after the particle size D50 reaches 5 μm, feeding is stopped and the crystals are transferred to a seed tank. Then, 10 kg of seed crystals are added to the bottom solution of 120 L of pure water, the ammonia molar concentration is 0.18 mol / L, and the pH is 10.80 for growth. The molten metal flow rate is 4~23 L / h, the ramp is 25 h, and the rotation speed is gradually decreased within the range of 400~120 rpm (20 h ramp). When the particle size reaches 11 μm, feeding is stopped.

[0062] S4: According to S3, when the particle size grows to 11.0 μm, stop feeding and the particles will not crack.

[0063] S5: According to S4, the slurry from the shutdown process is rinsed and dehydrated with pure water at 75℃. The washed material obtained after dehydration is dried in an oven at 120℃ until H2O < 5000 ppm, then cooled to room temperature. The dried material is then sieved through a 325-mesh vibrating screen to remove iron and packaged to obtain a nickel-cobalt-manganese ternary precursor with a particle size of 14.0 μm. Scanning electron microscope images at different magnifications are shown below. Figure 2 As shown, from Figure 2 It can be seen that it does not crack.

[0064] Example 3

[0065] The difference from Example 1 is that Ni with a D50 particle size of 14 μm was prepared. 0.96 Co 0.03 Mn 0.01 The (OH)2 ternary material precursor has an equivalent circle diameter of pores between primary particles of A and a thickness of primary particles of B, with A / (A+B)=0.55.

[0066] In S1, the total concentration of metal ions was adjusted to 2.0 mol / L, the concentration of the precipitant solution was 8 mol / L, and the concentration of the complexing agent solution was 5 mol / L.

[0067] In S2, the amount of pure water added was adjusted to 65 L, the pH of the reaction substrate was 12.3, the ammonia content was 0.20 mol / L, the reactor temperature was set to 60℃, the stirring speed was 480 r / min, the metal liquid flow rate was set to 1.8 L / h, and after 4 h of synthesis, the metal liquid flow rate was increased to 20 L / h (rate 2.25 L / h).

[0068] In S3, seed crystals are transferred when the particle size D50 reaches 4 μm.

[0069] In step S4, the amount of pure water added was adjusted to 160 L, the pH was set to 11.6, the ammonia content was 0.28 mol / L, and the stirring speed was 400 r / min. In step S6, the metal liquid flow rate was 6 L / h, increased to 25 L / h (rate 1.5 L / h) after 1 h of synthesis, and the stirring speed was reduced from 400 rpm to 150 rpm (rate 10 rpm / h). The remaining steps were the same as in Example 1, yielding a nickel-cobalt-manganese ternary precursor with similar scanning electron microscope (SEM) images. Figure 1 It won't crack.

[0070] Example 4

[0071] The difference from Example 1 is that Ni with a D50 particle size of 16 μm was prepared. 0.97 Co 0.02 Mn 0.01The (OH)2 ternary material precursor has an equivalent circle diameter of pores between primary particles of A and a thickness of primary particles of B, with A / (A+B)=0.60.

[0072] In S1, the total concentration of metal ions was adjusted to 2.5 mol / L, the concentration of the precipitant solution was 8.5 mol / L, and the concentration of the complexing agent solution was 5.5 mol / L.

[0073] In S2, the amount of pure water added was adjusted to 70 L, the pH of the reaction substrate was 12.5, the ammonia content was 0.20 mol / L, the reactor temperature was set to 65℃, the stirring speed was 450 r / min, the metal liquid flow rate was set to 2 L / h, and after 4 h of synthesis, the metal liquid flow rate was increased to 24 L / h (rate 2.5 L / h).

[0074] In S3, seed crystals are transferred when the particle size D50 reaches 4 μm.

[0075] In S4, the amount of pure water added was adjusted to 180 L, the pH was 11.7, the ammonia content was 0.30 mol / L, and the stirring speed was 350 r / min.

[0076] In step S6, the flow rate of the molten metal was 6.5 L / h, which was increased to 28 L / h (rate 2.15 L / h) after 1 h of synthesis, and the stirring speed was reduced from 350 rpm to 130 rpm (rate 12 rpm / h). The remaining steps were the same as in Example 1, yielding a nickel-cobalt-manganese ternary precursor with similar scanning electron microscope (SEM) images. Figure 1 It won't crack.

[0077] Comparative Example 1:

[0078] Ni with a particle size distribution D50 of 12 μm was prepared. 0.97 Co 0.01 Mn 0.02 The (OH)2 ternary material precursor has an equivalent circle diameter of pores between primary particles of A and a thickness of primary particles of B, with A / (A+B)=0.44.

[0079] S1: A ternary mixed salt aqueous solution with a total metal ion concentration of 2.3 mol / L was prepared by mixing soluble salts of nickel, cobalt, and manganese with pure water at a target molar ratio. The chemical formula of the precursor material is: Ni 0.97 Co 0.01 Mn 0.02 (OH)2; Prepare a sodium hydroxide precipitant solution with a concentration of 8 mol / L and an ammonia complexing agent solution with a concentration of 5.1 mol / L;

[0080] S2: Add pure water, complexing solution, and precipitant solution to the reactor, and purge with nitrogen for protection. The amount of pure water added is 70 L, and a reaction base solution with a pH of 12.50 and an ammonia content of 0.12 mol / L is prepared. The reactor temperature is 60℃, and the stirring speed is 500 r / min.

[0081] S3: The molten metal, precipitant, and complexing agent from S1 are introduced into the bottom liquid of step S2 for co-precipitation reaction, and nitrogen gas is continuously introduced for protection. The flow rate of molten metal is 3 L / h. After 8 h of synthesis, the flow rate of molten metal is increased to 20 L / h (rate 2.13 L / h). After 1.0 h of nucleation, the pH drops from 12.50 to 11.20. When the particle size D50 reaches 4 μm, the feeding is stopped and the sample is transferred to the seed tank.

[0082] S4: Add pure water, complexing solution, and precipitant solution to the reactor, and purge with nitrogen for protection. The amount of pure water added is 100 L, and a reaction base solution with a pH of 11.10 and an ammonia content of 0.18 mol / L is prepared. The reactor temperature is 63℃, and the reactor stirring speed is 420 r / min.

[0083] S5: Transfer the seed crystals prepared in S3 to the bottom solution of S4 at a dry weight of 5.8 kg;

[0084] S6: The molten metal, precipitant, and complexing agent from S1 are introduced into the bottom solution of step S5 for co-precipitation reaction, and nitrogen gas is continuously introduced for protection. The molten metal flow rate is 9 L / h. After 1 h of synthesis, the molten metal flow rate is increased to 16 L / h (rate 0.7 L / h), and the rotation speed is set to 400~120 rpm (rate 14 rpm / h).

[0085] S7: According to S6, when the particle size grows to 12 μm, stop feeding and the particles will crack.

[0086] S8: According to S7, the slurry from the shutdown process is rinsed and dehydrated with pure water at 75℃. The washed material obtained after dehydration is dried in an oven at 120℃ until H2O < 5000 ppm, then cooled to room temperature. The dried material is then sieved through a 325-mesh vibrating screen to remove iron and packaged to obtain nickel-cobalt-manganese ternary precursors with a particle size of 12 μm. Scanning electron microscope images at different magnifications are shown below. Figure 3 As shown, cracks have formed.

[0087] Comparative Example 2:

[0088] Ni with a particle size distribution D50 of 10.5 μm was prepared. 0.96 Co 0.02 Mn 0.02 The (OH)2 ternary material precursor has an equivalent circle diameter of pores between primary particles of A and a thickness of primary particles of B, with A / (A+B)=0.32.

[0089] S1: A ternary mixed salt aqueous solution with a total metal ion concentration of 2.3 mol / L was prepared by mixing soluble salts of nickel, cobalt, and manganese with pure water at a target molar ratio. The chemical formula of the precursor material is: Ni 0.96 Co 0.02 Mn 0.02 (OH)2; Prepare a sodium hydroxide precipitant solution with a concentration of 8 mol / L and an ammonia complexing agent solution with a concentration of 5.1 mol / L;

[0090] S2: Add pure water, complexing solution, and precipitant solution to the reactor, and purge with nitrogen for protection. The amount of pure water added is 80 L, and a reaction base solution with a pH of 12.60 and an ammonia content of 0.18 mol / L is prepared. The reactor temperature is 60℃, and the stirring speed is 480 r / min.

[0091] S3: The molten metal, precipitant, and complexing agent from S1 are introduced into the bottom liquid of step S2 for co-precipitation reaction, and nitrogen gas is continuously introduced for protection. The flow rate of molten metal is 2 L / h. After 3 h of synthesis, the flow rate of molten metal is increased to 20 L / h (rate 1.13 L / h). After 1.0 h of nucleation, the pH drops from 12.60 to 11.45. When the particle size D50 reaches 4.2 μm, the feed is stopped and the mixture is transferred to the seed tank.

[0092] S4: Add pure water, complexing solution, and precipitant solution to the reactor, and purge with nitrogen for protection. The amount of pure water added is 120 L, and a reaction base solution with a pH of 11.45 and an ammonia content of 0.18 mol / L is prepared. The reactor temperature is 65℃, and the stirring speed is 400 r / min.

[0093] S5: Transfer the seed crystals prepared in S3 to the bottom solution of S4 at a dry weight of 4.5 kg;

[0094] S6: The molten metal, precipitant, and complexing agent from S1 are introduced into the bottom solution from step S5 for co-precipitation reaction, and nitrogen gas is continuously introduced for protection. The molten metal flow rate is 4 L / h. After 1 h of synthesis, the molten metal flow rate is increased to 20 L / h (rate 0.8 L / h), and the rotation speed is set to 400~120 rpm (rate 14 rpm / h).

[0095] S7: According to S6, when the particle size grows to 10.5 μm, stop feeding, and the particles will crack.

[0096] S8: According to S7, the slurry from the shutdown process is rinsed and dehydrated with pure water at 75℃. The washed material obtained after dehydration is dried in an oven at 120℃ until H2O < 5000 ppm, then cooled to room temperature. The dried material is then sieved through a 325-mesh vibrating screen to remove iron and packaged to obtain nickel-cobalt-manganese ternary precursors with a particle size of 10.5 μm. The scanning electron microscope images at different magnifications are similar. Figure 3 , cracked.

[0097] Comparative Example 3

[0098] Ni with a particle size distribution D50 of 11.60 μm was prepared. 0.96 Co 0.02 Mn 0.02 The (OH)2 ternary material precursor has an equivalent circle diameter of pores between primary particles of A and a thickness of primary particles of B, with A / (A+B)=0.30.

[0099] S1: A ternary mixed salt aqueous solution with a total metal ion concentration of 2.3 mol / L is prepared by mixing soluble salts of nickel, cobalt, and manganese with pure water at a target molar ratio. The chemical formula of the precursor material is: Ni 0.96 Co 0.02 Mn 0.02 (OH)2; Prepare a sodium hydroxide precipitant solution with a concentration of 8 mol / L and an ammonia complexing agent solution with a concentration of 5.1 mol / L;

[0100] S2: Add pure water, complexing solution, and precipitant solution to the reactor, and purge with nitrogen for protection. The amount of pure water added is 150 L, to prepare a reaction base solution with a pH of 12.70 and an ammonia content of 0.17 mol / L. The reactor temperature is 55℃, and the stirring speed is 400 r / min.

[0101] S3: The molten metal, precipitant, and complexing agent from S1 are introduced into the bottom liquid of S2 for co-precipitation reaction, and nitrogen gas is continuously introduced for protection. The flow rate of molten metal is 3 L / h. After 16 h of synthesis, the flow rate of molten metal is increased to 22 L / h (rate 1.18 L / h). After 1.0 h of nucleation, the pH drops from 12.70 to 11.30. When the particle size D50 reaches 4 μm, the feed is stopped and the sample is transferred to the seed tank.

[0102] S4: Add pure water, complexing solution, and precipitant solution to the reactor, and purge with nitrogen for protection. The amount of pure water added is 110 L, and a reaction base solution with a pH of 11.30 and an ammonia content of 0.12 mol / L is prepared. The reactor temperature is 60℃, and the stirring speed is 400 r / min.

[0103] S5: Transfer the seed crystals prepared in S3 to the bottom solution of S4 at a dry weight of 11.28 kg;

[0104] S6: The molten metal, precipitant, and complexing agent from S1 are introduced into the bottom liquid of S5 for co-precipitation reaction, and nitrogen gas is continuously introduced for protection. The molten metal flow rate is 17 L / h. After 1 h of synthesis, the molten metal flow rate is increased to 27 L / h (rate 1 L / h). The rotation speed is set in the range of 450~120 rpm and gradually decreased (rate 14 rpm / h).

[0105] S7: According to S6, when the particle size grows to 11.60 μm, stop feeding, and the particles will crack.

[0106] S8: According to S7, the slurry from the shutdown process is washed and dehydrated with pure water at 75℃. The washed material obtained after dehydration is dried in an oven at 120℃ until H2O < 5000 ppm, then cooled to room temperature. The dried material is then sieved through a 325-mesh vibrating screen to remove iron and packaged to obtain a nickel-cobalt-manganese ternary precursor with a particle size of 11.60 μm. Its scanning electron microscope images at different magnifications are similar. Figure 3 , cracked.

[0107] It should be noted that the terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of this application described herein can be implemented, for example, in a sequence other than those described herein.

[0108] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A high-nickel, large-particle ternary precursor, comprising multiple secondary particles, wherein the secondary particles are composed of multiple primary particles, and multiple pores exist between the multiple primary particles, characterized in that... The chemical formula of the high-nickel large-particle ternary precursor is Ni x Co y Mn z (OH)2, wherein x+y+z=1, and 0.9≤x≤1.0, 0≤y≤0.1, 0≤z≤0.1; the D50 particle size of the high-nickel large-particle ternary precursor is 10~16 μm; The equivalent circle diameter of the pores between the primary particles is A, the thickness of the primary particles is B, A / (A+B)>0.45, and the average value of the equivalent circle diameter corresponding to each pore is the equivalent circle diameter of the pores between the primary particles.

2. The high-nickel large-particle ternary precursor according to claim 1, characterized in that, A / (A+B) is 0.46~0.

55.

3. A method for preparing the high-nickel large-particle ternary precursor as described in claim 1 or 2, characterized in that, The preparation method includes: Step S1: Prepare a metal liquid by mixing soluble nickel salt, soluble cobalt salt, soluble manganese salt and pure water according to the proportion of each element in the chemical formula of the high-nickel large-particle ternary precursor. Step S2: In a nitrogen atmosphere, the raw materials including the first precipitant solution, the first complexing agent solution, ammonia water and water are stirred and mixed to obtain the reaction base liquid; Step S3: In a nitrogen atmosphere, the molten metal, the second precipitant solution, and the second complexing agent solution are passed into the reaction substrate to carry out a co-precipitation reaction to obtain precursor secondary particles. When the D50 particle size of the precursor secondary particles grows to 10~16 μm, the feeding is stopped to obtain a high-nickel large-particle ternary precursor crude product. Step S4: The crude high-nickel large-particle ternary precursor is washed, dried, sieved, and iron removed sequentially to obtain the high-nickel large-particle ternary precursor. Wherein, the primary particles in the secondary particles of the precursor satisfy A / (A+B)>0.

45.

4. The method for preparing the high-nickel large-particle ternary precursor according to claim 3, characterized in that, In step S1, the total molar concentration of metal ions in the molten metal is 1~2.5 mol / L.

5. The method for preparing the high-nickel large-particle ternary precursor according to claim 3, characterized in that, In step S2, the pH value of the reaction substrate is 10.7~11.7, and the molar concentration of ammonia in the reaction substrate is 0.06~0.2950 mol / L.

6. The method for preparing the high-nickel large-particle ternary precursor according to any one of claims 3 to 5, characterized in that, In step S2, the stirring speed is 100~500 r / min; and / or the volume of water is 70~150 L; and / or the temperature of the reaction base liquid is 50~75℃.

7. The method for preparing the high-nickel large-particle ternary precursor according to any one of claims 3 to 5, characterized in that, In step S3, the flow rates of the molten metal, the second precipitant solution, and the second complexing agent solution gradually increase with the increase of reaction time; and / or the flow rate of the molten metal is 8.5~26 L / h.

8. The method for preparing the high-nickel large-particle ternary precursor according to any one of claims 3 to 5, characterized in that, In step S3, the coprecipitation reaction is stirred, and the stirring speed gradually decreases as the reaction time increases. The initial stirring speed is 400~550 rpm, and when the D50 particle size of the precursor secondary particles grows to 3~5 μm, the stirring speed gradually decreases in the range of 450~120 rpm.

9. The method for preparing the high-nickel large-particle ternary precursor according to any one of claims 3 to 5, characterized in that, In step S4, the drying temperature is 120~130℃ and the drying time is 1~8h.

10. The method for preparing the high-nickel large-particle ternary precursor according to any one of claims 3 to 5, characterized in that, In step S4, the water content of the washed high-nickel large-particle ternary precursor crude product is <5000 ppm.

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