Production device and method of wide-distribution micro-powder-free ternary precursor

文档序号：26400 发布日期：2021-09-24 浏览：16次中文

阅读说明：本技术 宽分布无微粉三元前驱体的生产装置及方法 (Production device and method of wide-distribution micro-powder-free ternary precursor ) 是由陈万超刘京星李沛荣杨燮宁李振辉吴芳罗爱平于 2021-08-26 设计创作，主要内容包括：本发明公开了一种宽分布无微粉三元前驱体的生产装置及方法,结构简单,生效效率高,适合宽分布无微粉三元前驱体的连续生产。三元前驱体组成为Ni-xCo-yM-(1-x-y)(OH)-2,其中,0.70≤x≤0.98,0.02≤y≤0.2,x+y<1,M为Mn或Al,粒度分布满足以下特征：1.0μm＜Dmin＜4.0μm,4.0μm＜D10＜7.0μm,9μm＜D50＜12μm,17.0μm＜D90＜25.0μm。所获得的宽分布无微粉三元前驱体形态好,具有较好的性能,对于提升三元前驱体电池的综合性能具有十分重要的意义。(The invention discloses a production device and a production method of a wide-distribution micro-powder-free ternary precursor, which are simple in structure, high in effective efficiency and suitable for continuous production of the wide-distribution micro-powder-free ternary precursor. The composition of the ternary precursor is Ni x Co y M 1‑x‑y (OH) 2 Wherein x is more than or equal to 0.70 and less than or equal to 0.98, y is more than or equal to 0.02 and less than or equal to 0.2, and x + y<1, M is Mn or Al, and the particle size distribution meets the following characteristics: dmin is more than 1.0 mu m and less than 4.0 mu m, D10 is more than 4.0 mu m and less than 7.0 mu m, D50 is more than 9 mu m and less than 12 mu m, and D90 is more than 17.0 mu m and less than 25.0 mu m. The obtained wide-distribution micro-powder-free ternary precursor has good shape and better performanceThe method has very important significance for improving the comprehensive performance of the ternary precursor battery.)

1. Production facility of no miropowder ternary precursor of wide distribution, its characterized in that includes:

the device comprises a main reaction device (100), wherein a plurality of main feed inlets (101) and a plurality of overflow outlets (102) are formed in the main reaction device (100);

the main stirring device (103) is connected with the main reaction device (100) and is used for stirring in the main reaction device (100) during the reaction of the ternary precursor;

the first overflow device (200) is connected with the main reaction device (100) through a first overflow pipeline (300), a first overflow valve (301) is arranged on the first overflow pipeline (300), and the first overflow pipeline (300) is opened or closed to control the slurry in the main reaction device (100) to overflow to the first overflow device (200) through the first overflow pipeline (300);

the first stirring device (203) is connected with the first overflow device (200) and is used for stirring in the first overflow device (200) during the reaction of the ternary precursor;

the first overflow device (200) is also provided with a first discharge opening (202) and a plurality of first feed openings (201);

the second overflow device (210) is connected with the main reaction device (100) through a second overflow pipeline (310), a second overflow valve (311) is arranged on the second overflow pipeline (310), and the second overflow pipeline (310) is opened or closed to control the slurry in the main reaction device (100) to overflow to the second overflow device (210) through the second overflow pipeline (310);

the second stirring device (213) is connected with the second overflow device (210) and is used for stirring in the second overflow device (210) during the ternary precursor reaction;

the second overflow device (210) is also provided with a second discharge opening (212) and a plurality of second feed openings (211).

2. The production device of the wide-distribution micropowder-free ternary precursor according to claim 1, characterized in that: the two opposite ends of the first overflow pipeline (300) are arranged in a high-low mode, wherein the end, connected with the first overflow pipeline (300), of the main reaction device (100) is higher than the other end, connected with the first overflow pipeline (300), of the main reaction device (100) opposite to the first overflow device (200).

3. The production device of the wide-distribution micropowder-free ternary precursor according to claim 1, characterized in that: and a filtering device (400) is further arranged in the first overflow device (200) and the second overflow device (210) and is used for filtering the mother liquor in the first overflow device (200) and the second overflow device (210) and improving the reaction concentration of the slurry in the first overflow device (200) and the second overflow device (210).

4. The production device of the wide-distribution micropowder-free ternary precursor according to claim 1, characterized in that: the number of the main feed inlet (101), the first feed inlet (201) and the second feed inlet (211) is at least three.

5. The production device of the wide-distribution micropowder-free ternary precursor according to claim 3, characterized in that: the filtering device (400) is positioned at the upper part of the first overflow device (200) or/and the second overflow device (210) and is close to the inner side wall but not in contact with the inner side wall.

6. The production device of the wide-distribution micropowder-free ternary precursor according to claim 5, characterized in that: the filtering device (400) is also connected with a mother liquor collecting tank (403) through a mother liquor conveying pipeline (401).

7. The production device of the wide-distribution micropowder-free ternary precursor according to claim 6, characterized in that: an air-operated diaphragm pump (402) is further arranged between the mother liquor conveying pipeline (401) and the mother liquor collecting tank (403) to provide negative pressure so that the mother liquor in the first overflow device (200) or/and the second overflow device (210) is filtered out of the mother liquor conveying pipeline (401).

8. The production device of the wide-distribution micropowder-free ternary precursor according to claim 7, characterized in that: a pressure regulating valve (404) is also arranged between the pneumatic diaphragm pump (402) and the filter device (400).

9. The production device of the wide-distribution micropowder-free ternary precursor according to claim 8, characterized in that: the number of the overflow ports (102) is at least two.

10. A method for producing a broad distribution micropowder-free ternary precursor using the production apparatus for a broad distribution micropowder-free ternary precursor according to any one of claims 1 to 9, characterized by comprising the steps of:

(2) adding a proper amount of pure water and an ammonia water solution into the main reaction device (100) to serve as a base solution, enabling the concentration of ammonia radicals in the base solution to be 0.1-1.0 mol/L, stirring, and adding a ternary precursor seed crystal with the same composition as that of the metal elements in the solution A;

(3) sealing the main reaction device (100), introducing a first protective gas, simultaneously pumping the solution A, the solution B and the solution C into the main reaction device (100) in proportion, stirring, controlling the temperature to be 40-70 ℃ and the pH value to be 11.5-12.5, and when the liquid level of the main reaction device (100) is full, enabling the slurry in the main reaction device (100) to overflow to the first overflow device (200) communicated with the main reaction device;

(4) when the slurry overflows to a 75-80% volume liquid level of the first overflow device (200), sealing the first overflow device (200), introducing a protective gas II, simultaneously pumping the solution A, the solution B and the solution C into the first overflow device (200) in proportion, stirring, controlling the temperature at 40-70 ℃ and the pH value to be 1.0 less than the pH value of the main reaction device (100), filtering to discharge mother liquor when the liquid level of the first overflow device (200) is full, continuously remaining ternary precursor particles in the first overflow device (200) for growth until the particle size reaches the requirement, stopping feeding, completely transferring all materials in the first overflow device (200), entering a post-treatment stage, and emptying the first overflow device (200) for later use;

(5) closing the first overflow valve (301) and opening the second overflow valve (311) when the slurry overflows to the 75-80% volume liquid level of the first overflow device (200), wherein the slurry in the main reaction device (100) begins to overflow to the second overflow device (210) communicated with the main reaction device, and when the slurry overflows to the 75-80% volume liquid level of the second overflow device (210), the second overflow device (210) is produced according to the same method as the first overflow device (200) in the step (4);

(6) when the slurry overflows to the volume liquid level of 75-80% of the volume liquid level of the second overflow device (210), the slurry in the main reaction device (100) starts to overflow to other overflow devices communicated with the main reaction device or the first overflow device (200), and when the slurry overflows to the volume liquid level of 75-80% of the volume liquid level of other overflow devices or the first overflow device (200), the other overflow devices or the first overflow device (200) are produced according to the same method as the first overflow device (200) in the step (4), and the steps are repeated in a circulating mode.

Technical Field

The invention belongs to the field of new energy materials, and particularly relates to a production device of a wide-distribution micro-powder-free ternary precursor and a method for producing the wide-distribution micro-powder-free ternary precursor by using the production device.

Background

The lithium ion battery is rapidly developed in the application market of the electric automobile, the lithium ion battery with high specific energy density is developed, the cost of the power battery is reduced to improve the competitiveness of the new energy automobile on the fuel automobile, and the current urgent need is met. The ternary positive electrode material has higher reversible capacity and voltage platform than the lithium iron phosphate material, has more obvious cost advantage than the lithium cobaltate material, and becomes the main selection scheme of the current electric passenger vehicle.

The ternary precursor is a key material for producing the ternary cathode, the ternary precursor is mixed with a lithium source and then sintered to prepare the ternary cathode material, and the particle size distribution of the ternary precursor directly determines the particle size distribution of the ternary cathode material. The current research shows that the ternary precursor material with the granularity in wide distribution has the advantages of high compaction density, high volume energy density and the like, and can be widely applied to the market. However, due to the synthetic property of the material, a large amount of micro powder (particles with Dmin less than 1 μm) exists in the product, and the micro powder is easy to overcharge and overdischarge in the charging and discharging processes of the battery, so that the internal structure of the material is damaged, the electrochemical activity is lost, and the reversible capacity of the battery is reduced; on the other hand, the material with the damaged part of the structure is easy to generate side reaction with electrolyte, and releases heat, so that the thermal runaway of the battery is finally caused, and the potential safety hazard is brought. Therefore, the safety performance of the cathode material obtained by sintering the ternary precursor containing the micro powder is poor.

At present, in the prior art, a single-kettle or multi-kettle continuous production mode is mainly adopted for controlling a crystallization coprecipitation method in the preparation of a wide-distribution ternary precursor. According to the process flow, through the overflow design and the feeding design of a special reaction device, the generation of small crystal nuclei and the growth of large particles are simultaneously carried out in the same reaction system, the particle size distribution is wide, material particles are continuously overflowed out of the reaction device after being produced in the reaction device for a certain time, the feeding and the product discharging are synchronously carried out, and the overflow reaction of the small particles cannot be avoided. Or the overflow needs a longer time to grow the micro powder and avoid or reduce the generation of the micro powder.

Although this method can obtain a widely distributed ternary precursor material, it inevitably has a large amount of fine powder particles due to the limitations of the production method itself. Although a fraction of small particles can be removed by sieving after sintering, most of the small particles agglomerate or stick to large particles during sintering and cannot be removed by sieving at all. At the same time, this also results in increased downstream product production costs.

Therefore, the method for preparing the wide-distribution micro-powder-free ternary precursor has high production efficiency and an acceptable cost interval, and has very important significance for the whole ternary battery material industry and the improvement of the comprehensive performance of the ternary cathode material.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the related art. Therefore, the invention aims to provide a preparation method of a wide-distribution micropowder-free ternary precursor, which has proper production cost and higher production efficiency. The second purpose of the invention is to provide the wide-distribution micropowder-free ternary precursor obtained by the preparation method. The third purpose of the invention is to provide the reaction device for the wide-distribution micro-powder-free ternary precursor, which is suitable for the continuous production of the wide-distribution micro-powder-free ternary precursor.

The generation reason of the micro powder is complex and depends on comprehensive utilization of stirring speed, reaction temperature, reaction pH, feeding flow, material concentration, reaction time and the like during reaction, the wide-distribution micro powder-free ternary precursor is that the particle size distribution is relatively dispersed, and no (micro) powder particles with Dmin less than 1 mu m exist in the laser particle sizer test.

In the present invention, it should be understood by those skilled in the art that the numbers of steps (1) to (6) in the preparation method of the broad-distribution micropowder-free ternary precursor are used as labels only, and do not limit the preparation sequence of the present invention, and those skilled in the art can appropriately adjust the sequence as needed. For example, in the present invention, the solutions A, B and C are prepared in step (1) and the base solutions are prepared in step (2) sequentially or simultaneously.

The technical scheme adopted by the invention is as follows:

in a first aspect, the invention provides a preparation method of a wide-distribution micropowder-free ternary precursor, which comprises the following steps:

(1) preparing a mixed salt solution A to ensure that the total metal concentration in the solution A is 1.0-2.0 mol/L; preparing a solution B, wherein the concentration of hydroxyl in the solution B is 5.0-12.0 mol/L; preparing an ammonia water solution C with the ammonia radical concentration of 5.0-12.0 mol/L; the solution A is a sulfate, chloride or nitrate solution of nickel, cobalt and manganese, and certainly, when aluminum is used for replacing manganese to form a ternary precursor of NCA, the solution A can also be a sulfate, chloride or nitrate solution of nickel, cobalt and aluminum.

In some embodiments of the present invention, the molar ratio of the nickel ions, the cobalt ions, and the manganese (aluminum) ions in the solution a may be adjusted according to actual needs, which is not specifically limited by the present invention.

In some embodiments of the invention, the solution B is at least one of sodium hydroxide and potassium hydroxide

(2) Adding a proper amount of pure water and an ammonia water solution into a main reaction device to serve as a base solution, enabling the concentration of ammonia radicals in the base solution to be 0.1-1.0 mol/L, stirring, and adding a ternary precursor seed crystal with the same composition as that of a metal element in the solution A;

(3) sealing the main reaction device, introducing a protective gas I, simultaneously pumping the solution A, the solution B and the solution C into the main reaction device in proportion, stirring, controlling the temperature to be 40-70 ℃ and the pH value to be 11.5-12.5, and when the liquid level of the main reaction device is full, enabling the slurry in the main reaction device to overflow to a first overflow device communicated with the main reaction device;

(4) when the slurry overflows to a 75-80% volume liquid level of a first overflow device, sealing the first overflow device, introducing a second protective gas, simultaneously pumping the solution A, the solution B and the solution C into the first overflow device in proportion, stirring, controlling the temperature to be 40-70 ℃, controlling the pH value to be 1.0 less than that in a main reaction device, gradually growing ternary precursor particles in the first overflow device along with continuous entering of the solution A, the solution B and the solution C, discharging a mother liquid by using a filtering device when the liquid level of the first overflow device is full, continuously remaining the ternary precursor particles in the first overflow device for growing until the particle size meets the requirement, stopping feeding, completely transferring the materials in the first overflow device, entering a post-treatment stage, and emptying the first overflow device for later use;

(5) when the slurry overflows to the 75-80% volume liquid level of the first overflow device, closing the first overflow valve, and opening the second overflow valve, wherein the slurry in the main reaction device begins to overflow to a second overflow device communicated with the main reaction device, and when the slurry overflows to the 75-80% volume liquid level of the second overflow device, the second overflow device is produced according to the same method as the first overflow device in the step (4);

(6) and (3) when the slurry overflows to the 75-80% volume liquid level of the second overflow device, the slurry in the main reaction device begins to overflow to other overflow devices or the first overflow device communicated with the main reaction device, and when the slurry overflows to the 75-80% volume liquid level of the other overflow devices or the first overflow device, the other overflow devices or the first overflow device are produced according to the same method as the first overflow device in the step (4), and the steps are repeated in a circulating mode.

It should be understood that the number of overflow devices in the present invention is not to be construed as limiting the present invention. The number of overflow means in the present invention is not particularly limited. In fact, when the first overflow means and the second overflow means overflow, it is sufficient to realize the cyclic continuous production of the solution of the invention. In the present invention, other overflow devices are described, and only the description of the cyclic reciprocating continuous production is used, and those skilled in the art can increase or decrease the number of overflow devices according to the needs of the process.

In the invention, the pH value of the reaction in the step (4) is controlled to be lower than that in the step (3) by about 1.0, and the aim is to control the metal salt solution entering the first overflow device or other overflow devices to grow on the original seed crystal as far as possible, so that independent nucleation is not performed, ternary precursor micro powder particles are not generated, and the product quality is improved. If the pH value of the reaction in the step (4) is kept consistent with that of the reaction in the step (3), the ternary precursor particles are easy to nucleate independently again in the growth process of the ternary precursor particles in the step (4) under a high pH environment, and the effect of removing the ternary precursor micro powder particles cannot be achieved. Or the reaction needs a very long time to grow the independently nucleated ternary precursor micro-powder particles. And too long growth time can also lead to too wide particle size distribution of the final ternary precursor particle product, thereby causing performance degradation.

Different pH values have obvious influence on the nucleation speed and the growth speed of the crystal, and when the pH value is lower, the growth speed of the precursor particles is higher than the nucleation speed due to smaller supersaturation degree in the solution, so that the particles with better appearance are easy to obtain. Under the condition of high pH value, the supersaturation degree in a solution system is larger, the formation rate of crystal nucleus is very fast, and the growth rate of precursor particles is slower, so that a micro powder structure with smaller particles is easily formed. Therefore, in some embodiments of the present invention, it is suitable that the pH value of the reaction in the step (4) is controlled to be 10.5 to 11.5. In other embodiments of the present invention, the pH value of the reaction in the step (4) is controlled to be 10.5 to 11.2.

In some embodiments of the invention, the post-treatment stage in step (4) comprises: and carrying out solid-liquid separation, pure water washing and drying on the precursor solution in the first overflow device to obtain the wide-distribution micropowder-free ternary precursor. In some embodiments of the invention, the number of times of washing with pure water is 1-5, the drying temperature is 110-150 ℃, and the drying time is 1-10 hours. Particularly, in the invention, after the drying step, the post-treatment processes such as screening, demagnetizing and the like can be carried out, so that partial caking or introduced impurities caused in the preceding process steps such as drying and the like are reduced, and the product is packaged and put in storage.

In some embodiments of the invention, the ternary precursor seed crystal in step (2) is a ternary precursor particle with 9 μm < D50 < 12 μm, and the element composition of the ternary precursor seed crystal is the same as the metal element in solution a, if solution a is a solution of nickel cobalt manganese, the ternary precursor seed crystal is a ternary precursor particle of nickel cobalt manganese; and if the solution A is a nickel-cobalt-aluminum solution, the ternary precursor seed crystal is a nickel-cobalt-aluminum ternary precursor particle.

In some embodiments of the invention, the seed crystal is a ternary precursor particle of NCM (nickel cobalt manganese) or NCA (nickel cobalt aluminum) of 9 μm < D50 < 12 μm. In other embodiments of the present invention, the ternary precursor seed is a 9.5 μm D50 μm 11 μm NCM or NCA ternary precursor particle.

In some embodiments of the present invention, the shielding gas in step (3) is at least one of nitrogen, argon, helium; and (4) the second protective gas in the step (4) is at least one of nitrogen, argon and helium. In some embodiments of the present invention, the shielding gas one and the shielding gas two may be the same or different. In some embodiments of the invention, the first shielding gas and the second shielding gas are both nitrogen.

In some embodiments of the present invention, the stirring speed in the step (3) is controlled to be 150 to 300 rpm.

In some embodiments of the present invention, the stirring speed in the step (4) is controlled to be 80-150 rpm. And (3) controlling the stirring speed in the step (4) to be 80-150 rpm, and aiming at preventing the more complete particle sphere shape from being maintained and improving the comprehensive performance of the product in the process that the product gradually forms a sphere in the growth stage of the ternary precursor particles in the step (4). Because in the process of the growth of the ternary precursor, along with the continuous filtering of the mother liquor, the solid contents of the materials in the first overflow device and the second overflow device are gradually increased, if the stirring speed is not reduced, the collision frequency and the collision strength among the spherical particles of the ternary precursor can be gradually increased, and the spherical body is very easy to crack. In some embodiments of the invention, by reducing the stirring speed, the collision frequency and strength between ternary precursor sphere particles can be effectively reduced, and the generation of micro powder caused by the breakage of product spheres is avoided.

In some embodiments of the present invention, the continuous entering time of the solution A, the solution B and the solution C in the step (4) is 5-20 h. And (4) continuously introducing the solution A, the solution B and the solution C in the step (4) to continuously produce the ternary precursor crystal nucleus so as to achieve the target granularity and simultaneously remove the micro powder. The reaction time is not particularly limited, but in some embodiments of the present invention, the reaction growth in step (4) is carried out for 5 to 20 hours, and a wide-distribution, fine-powder-free ternary precursor as described below can be obtained.

A wide-distribution micro-powder-free ternary precursor with the composition of Ni_xCo_yM_1-x-y(OH)₂Wherein x is more than or equal to 0.70 and less than or equal to 0.98, y is more than or equal to 0.02 and less than or equal to 0.2, and x + y<1, M is a metal element Mn or Al, and the particle size distribution of the ternary precursor meets the following characteristics: dmin is more than 1.0 mu m and less than 4.0 mu m, D10 is more than 4.0 mu m and less than 7.0 mu m, D50 is more than 9 mu m and less than 12 mu m, and D90 is more than 17.0 mu m and less than 25.0 mu m.

In a second aspect, the present invention also provides a wide-distribution micropowder-free ternary precursor reaction apparatus, comprising:

the device comprises a main reaction device 100, wherein a plurality of main feed inlets 101 and a plurality of overflow outlets 102 are arranged on the main reaction device 100;

a main stirring device 103 connected to the main reaction device 100, for stirring in the main reaction device 100 during the ternary precursor reaction;

a first overflow device 200 connected to the main reactor 100 via a first overflow pipe 300, wherein the first overflow pipe 300 is provided with a first overflow valve 301, and the first overflow pipe 300 is opened or closed to control the slurry in the main reactor 100 to overflow to the first overflow device 200 via the first overflow pipe 300;

a first stirring device 203 connected with the first overflow device 200 and used for stirring in the first overflow device 200 during the ternary precursor reaction;

the first overflow device 200 is further provided with a first discharge port 202 and a plurality of first feed ports 201;

a second overflow device 210 connected to the main reactor 100 via a second overflow pipe 310, wherein the second overflow pipe 310 is provided with a second overflow valve 311, and the second overflow pipe 310 is opened or closed to control the slurry in the main reactor 100 to overflow to the second overflow device 210 via the second overflow pipe 310;

and a second stirring device 213 connected to the second overflow device 210, for stirring in the second overflow device 210 during the ternary precursor reaction.

The second overflow means 210 is further provided with a second discharge opening 212 and a plurality of second feed openings 211.

Further, the two ends of the first overflow pipe 300 are disposed at opposite positions, wherein one end of the main reaction device 100 connected to the first overflow pipe 300 is higher than the other end of the main reaction device 200 connected to the first overflow pipe 300. So that the slurry in the main reaction device 100 overflows into the first overflow device 200 through the first overflow conduit 300. Similarly, the second overflow pipe 310 is also disposed between the main reaction device 100 and the second overflow device at the high end and the low end. On one hand, the slurry in the main reaction device can overflow to the first overflow device or the second overflow device conveniently, and on the other hand, the slurry in the first overflow device or the second overflow device can be prevented from flowing back to the main reaction device as far as possible, and precursors with different particle sizes are introduced, so that the particle sizes are unstable.

Further, a filtering device 400 is further disposed in the first overflow device 200 and the second overflow device 210, and is used for filtering the mother liquor in the first overflow device 200 and the second overflow device 210, so as to increase the reaction concentration of the slurry in the first overflow device 200 and the second overflow device 210. Promoting the growth of the ternary precursor, inhibiting the nucleation of the ternary precursor under proper conditions and avoiding the existence of micro powder with the granularity less than 1 mu m in the final product.

Further, the number of the first feed openings 201 is at least three. In general, the number of the first feed ports is set to three in consideration of the fact that the material synthesized into the ternary system facilitates the transport of the raw material. Of course, the number of the first feed inlets may also be four or more, and the implementation of the technical scheme of the invention is not affected. It should also be mentioned that the number of the feed inlets in the present invention may be one, and at this time, the raw materials of the ternary system only need to be added through different pipelines through one feed inlet.

Further, the number of the second feed ports 211 is at least three. Here, considering that the material synthesized as a ternary system facilitates the transport of the raw material, the number of the second feed ports is set to three. Of course, the number of the second feed openings may also be four or more, or the number of the second feed openings may also be one, which does not affect the implementation of the technical solution of the present invention.

Further, the number of the main feed ports 101 is at least three. Here, considering that the material synthesized as a ternary system facilitates the transport of the raw material, the number of the main feed ports is set to three. Of course, the number of the main feed inlets may also be four or more, or the number of the main feed inlets may also be one, which does not affect the implementation of the technical solution of the present invention.

In the invention, the number of the main feed inlets, the number of the first feed inlets and the number of the second feed inlets may be the same or different.

Further, the filtering device 400 is located at a position close to but not in contact with the inner sidewall at the upper portion of the first overflow device 200 or/and the second overflow device 210.

Further, the filtering device 400 is also connected with a mother liquor collecting tank 403 through a mother liquor conveying pipeline 401. An air operated diaphragm pump 402 is further disposed between the mother liquor conveying pipeline 401 and the mother liquor collecting tank 403 to provide negative pressure, so that the mother liquor in the first overflow device 200 or/and the second overflow device 210 is filtered out from the mother liquor conveying pipeline 401.

Further, a pressure regulating valve 404 is disposed between the air operated diaphragm pump 402 and the filter device 400. The negative pressure in the filtering device is adjusted, and the filtering speed of the mother liquor in the first overflow device and/or the second overflow device is controlled.

The method for producing the wide-distribution micro-powder-free ternary precursor by using the production device of the wide-distribution micro-powder-free ternary precursor comprises the following steps:

(2) adding a proper amount of pure water and an ammonia water solution into the main reaction device 100 to serve as a base solution, enabling the concentration of ammonia radicals in the base solution to be 0.1-1.0 mol/L, stirring, and adding a ternary precursor seed crystal with the same composition as that of the metal elements in the solution A;

(3) sealing the main reaction device 100, introducing a first protective gas, simultaneously pumping the solution A, the solution B and the solution C into the main reaction device 100 in proportion, stirring, controlling the temperature at 40-70 ℃ and the pH value at 11.5-12.5, and when the liquid level of the main reaction device 100 is full, enabling the slurry in the main reaction device 100 to overflow to the first overflow device 200 communicated with the main reaction device 100;

(4) when slurry overflows to a liquid level of 75-80% of the volume of the first overflow device 200, sealing the first overflow device 200, introducing a protective gas II, simultaneously pumping the solution A, the solution B and the solution C into the first overflow device 200 in proportion, stirring, controlling the temperature to be 40-70 ℃, controlling the pH value to be 1.0 less than the pH value of the main reaction device 100, when the first overflow device 200 is full of liquid level, filtering to discharge mother liquid, continuously remaining ternary precursor particles in the first overflow device 200 for growth, stopping feeding until the particle size reaches the requirement, completely transferring all materials in the first overflow device 200, entering a post-treatment stage, and emptying the first overflow device 200 for later use;

(5) closing the first overflow valve 301 and opening the second overflow valve 311 while overflowing the slurry to 75-80% of the volume liquid level of the first overflow device 200, wherein the slurry in the main reaction device 100 begins to overflow to the second overflow device 210 communicated with the main reaction device, and when overflowing the slurry to 75-80% of the volume liquid level of the second overflow device 210, the second overflow device 210 is produced by the same method as the first overflow device 200 in the step (4);

(6) when the slurry overflows to the 75-80% volume liquid level of the second overflow device 210, the slurry in the main reaction device 100 starts to overflow to other overflow devices communicated with the main reaction device or the first overflow device 200, and when the slurry overflows to the 75-80% volume liquid level of other overflow devices or the first overflow device 200, the other overflow devices or the first overflow device 200 are produced according to the same method as the first overflow device 200 in the step (4), and the steps are repeated in a circulating mode.

The invention has at least one of the following beneficial effects:

(1) the wide-distribution micro-powder-free ternary precursor is wide in particle size distribution, free of micro powder, accurate and controllable in particle size and good in stability.

(2) The preparation method of the wide-distribution micropowder-free ternary precursor is simple to operate, good in continuity, stable in product and high in production efficiency, and the wide-distribution micropowder-free ternary precursor particles with target particle sizes can be obtained after reaction for 5-26 hours.

(3) The wide-distribution micro-powder-free ternary precursor reaction device is suitable for continuous production operation, high in production efficiency, high in productivity and low in production cost, can be used for preparing the wide-distribution micro-powder-free ternary precursor, has very important significance for improving the safety performance, the cycle performance, the service life and the like of a battery, and effectively solves the related problems of high cost, low production efficiency and the like of micro powder existing in ternary precursor particles or micro powder removal in the current preparation method.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a schematic flow diagram of a preparation method of a wide-distribution micropowder-free ternary precursor of the present invention.

FIG. 2 is a schematic structural diagram of a wide-distribution micropowder-free ternary precursor production device of the present invention.

Fig. 3 is a SEM schematic of a broad distribution micropowder-free ternary precursor in accordance with embodiments 1-4 of the present invention.

FIG. 4 is a SEM illustration of the broad distribution micropowder-free ternary precursors of comparative examples 1-4 of the present invention.

Fig. 5 is a SEM schematic of a broad distribution micropowder-free ternary precursor according to embodiments 6-9 of the present invention.

FIG. 6 is a SEM illustration of a broad distribution micropowder-free ternary precursor according to embodiments 10-12 of the present invention.

Fig. 7 is a SEM illustration of a broad distribution micropowder-free ternary precursor of embodiments 14/15 and 17/18 of the present invention.

Fig. 8 is a laser particle size test data plot of a broad distribution micropowder-free ternary precursor in accordance with embodiments 1-2 of the present invention.

FIG. 9 is a plot of laser particle size test data for the broad distribution, non-micropowder, ternary precursors of comparative examples 1-2 of the present invention.

FIG. 10 is a plot of laser particle size test data for comparative examples 3-4 of the present invention, broad distribution, non-micropowder, ternary precursors.

Wherein, in fig. 2, each reference numeral corresponds as follows:

a main reaction device-100, a main feeding hole-101, an overflow hole-102 and a main stirring device-103;

a first overflow device-200, a first stirring device-203, a first discharge opening-202 and a first feed opening-201;

a second overflow device 210, a second stirring device-213, a second discharge opening-212 and a second feed opening-211;

a first overflow pipeline-300, a first overflow valve-301, a second overflow pipeline-310 and a second overflow valve-311;

a filtering device-400, a mother liquor conveying pipeline-401, a pneumatic diaphragm pump-402, a mother liquor collecting tank-403 and a pressure regulating valve-404.

Detailed Description

The present invention will be described in detail with reference to the following embodiments. The following embodiments will assist those skilled in the art in further understanding the present invention, but are not intended to limit the invention in any way. It should be noted that variations and modifications can be made by persons skilled in the art without departing from the spirit of the invention. All falling within the scope of the present invention.

Embodiment 1:

(1) preparing a sulfate solution A of nickel, cobalt and aluminum according to a preset proportion to enable the total metal concentration in the solution A to be 1.6 mol/L; preparing a sodium hydroxide solution B with the hydroxide radical concentration of 10.0 mol/L; preparing an ammonia water solution C with the ammonia radical concentration of 9.0 mol/L;

(2) adding a proper amount of pure water and ammonia water solution into a main reaction device to serve as base solution, enabling the concentration of ammonia radicals in the base solution to be 0.8mol/L, stirring, and adding NCA ternary precursor crystal seeds with the D50 being 10.0 mu m;

(3) sealing the main reaction device, introducing argon as protective gas, simultaneously pumping the solution A, the solution B and the solution C into the main reaction device in proportion, controlling the stirring speed to be 200rpm, controlling the temperature to be 65 ℃ and the pH value to be 12.5, and when the liquid level of the main reaction device is full, enabling the slurry in the main reaction device to overflow to a first overflow device communicated with the main reaction device;

(4) when the slurry overflows to a liquid level of 75-80% of the volume of the first overflow device, sealing the first overflow device, introducing argon as a protective gas, simultaneously pumping the solution A, the solution B and the solution C into the first overflow device in proportion, controlling the stirring speed to be 100rpm, the temperature to be 70 ℃, and the pH value to be 11.5, gradually growing ternary precursor particles in the first overflow device along with the continuous entering of the solution A, the solution B and the solution C, discharging a mother liquid by using a filtering device when the liquid level of the first overflow device is full, continuously remaining the ternary precursor particles in the first overflow device for growing until the particle size meets the requirement, stopping feeding, completely transferring the materials in the first overflow device, entering a post-treatment stage, and emptying the first overflow device for later use; the total reaction time of the ternary precursor particles in the first overflow device was 10 hours.

(5) When the slurry overflows to the 75-80% volume liquid level of the first overflow device, closing the first overflow valve, opening the second overflow valve, and enabling the slurry in the main reaction device to overflow to a second overflow device communicated with the main reaction device;

(6) and (4) when the slurry overflows to the 75-80% volume liquid level of the second overflow device, the slurry in the main reaction device begins to overflow to the first overflow device communicated with the main reaction device, and when the slurry overflows to the 75-80% volume liquid level of the first overflow device, the production is carried out according to the same method as the step (4), and the steps are repeated in a circulating mode.

Embodiment 2:

(1) preparing a sulfate solution A of nickel, cobalt and aluminum according to a preset proportion to enable the total metal concentration in the solution A to be 1.5 mol/L; preparing a sodium hydroxide solution B with the hydroxide radical concentration of 6.0 mol/L; preparing an ammonia water solution C with the ammonia radical concentration of 7.0 mol/L;

(2) adding a proper amount of pure water and ammonia water solution into a main reaction device to serve as base solution, enabling the concentration of ammonia radicals in the base solution to be 0.5mol/L, stirring, and adding NCA ternary precursor crystal seeds with D50 being 9.0 mu m;

(3) sealing the main reaction device, introducing nitrogen as protective gas, simultaneously pumping the solution A, the solution B and the solution C into the main reaction device in proportion, controlling the stirring speed to be 300rpm, the temperature to be 55 ℃ and the pH value to be 11.5, and when the liquid level of the main reaction device is full, enabling the slurry in the main reaction device to overflow to a first overflow device communicated with the main reaction device;

(4) when the slurry overflows to a liquid level of 75-80% of the volume of the first overflow device, sealing the first overflow device, introducing nitrogen as protective gas, simultaneously pumping the solution A, the solution B and the solution C into the first overflow device in proportion, controlling the stirring speed to be 90rpm, the temperature to be 50 ℃, and the pH value to be 10.5, gradually growing ternary precursor particles in the first overflow device along with the continuous entering of the solution A, the solution B and the solution C, discharging mother liquor by using a filtering device when the liquid level of the first overflow device is full, continuously remaining the ternary precursor particles in the first overflow device for growing until the particle size meets the requirement, stopping feeding, completely transferring materials in the first overflow device, entering a post-treatment stage, and emptying the first overflow device for later use; the total reaction time of the ternary precursor particles in the first overflow device was 5 hours.

Embodiment 3:

(1) preparing a sulfate solution A of nickel, cobalt and aluminum according to a preset proportion to ensure that the total metal concentration in the solution A is 2.0 mol/L; preparing a sodium hydroxide solution B with the hydroxide radical concentration of 8.0 mol/L; preparing an ammonia water solution C with the ammonia radical concentration of 8.0 mol/L;

(2) adding a proper amount of pure water and ammonia water solution into a main reaction device to serve as base solution, enabling the concentration of ammonia radicals in the base solution to be 0.7mol/L, stirring, and adding NCA ternary precursor crystal seeds with the D50 being 10.0 mu m;

(3) sealing the main reaction device, introducing nitrogen as protective gas, simultaneously pumping the solution A, the solution B and the solution C into the main reaction device in proportion, controlling the stirring speed to be 300rpm, controlling the temperature to be 60 ℃, controlling the pH value to be 12.2, and enabling the slurry in the main reaction device to overflow to a first overflow device communicated with the main reaction device when the liquid level of the main reaction device is full;

(4) when the slurry overflows to a 75-80% volume liquid level of a first overflow device, sealing the first overflow device, introducing nitrogen as protective gas, simultaneously pumping the solution A, the solution B and the solution C into the first overflow device in proportion, controlling the stirring speed to be 110rpm, the temperature to be 55 ℃, and the pH value to be 11.2, gradually growing ternary precursor particles in the first overflow device along with the continuous entering of the solution A, the solution B and the solution C, discharging mother liquor by using a filtering device when the liquid level of the first overflow device is full, continuously remaining the ternary precursor particles in the first overflow device for growing until the particle size meets the requirement, stopping feeding, completely transferring materials in the first overflow device, entering a post-treatment stage, and emptying the first overflow device for later use; the total reaction time of the ternary precursor particles in the first overflow device was 7 hours.

Embodiment 4:

(1) preparing a sulfate solution A of nickel, cobalt and aluminum according to a preset proportion to enable the total metal concentration in the solution A to be 1.2 mol/L; preparing a sodium hydroxide solution B with the hydroxide radical concentration of 7.0 mol/L; preparing an ammonia water solution C with the ammonia radical concentration of 6.0 mol/L;

(2) adding a proper amount of pure water and ammonia water solution into a main reaction device to serve as base solution, enabling the concentration of ammonia radicals in the base solution to be 0.9mol/L, stirring, and adding NCA ternary precursor crystal seeds with the D50 being 10.5 mu m;

(3) sealing the main reaction device, introducing argon as protective gas, simultaneously pumping the solution A, the solution B and the solution C into the main reaction device in proportion, controlling the stirring speed to be 200rpm, controlling the temperature to be 60 ℃, controlling the pH value to be 12.3, and when the liquid level of the main reaction device is full, enabling the slurry in the main reaction device to overflow to a first overflow device communicated with the main reaction device;

(4) when the slurry overflows to a 75-80% volume liquid level of a first overflow device, sealing the first overflow device, introducing nitrogen as protective gas, simultaneously pumping the solution A, the solution B and the solution C into the first overflow device in proportion, controlling the stirring speed to be 80rpm, the temperature to be 65 ℃, and the pH value to be 11.3, gradually growing ternary precursor particles in the first overflow device along with the continuous entering of the solution A, the solution B and the solution C, discharging mother liquor by using a filtering device when the liquid level of the first overflow device is full, continuously remaining the ternary precursor particles in the first overflow device for growing until the particle size meets the requirement, stopping feeding, completely transferring materials in the first overflow device, entering a post-treatment stage, and emptying the first overflow device for later use; the total reaction time of the ternary precursor particles in the first overflow device was 8 hours.

Embodiment 5:

(1) preparing a sulfate solution A of nickel, cobalt and aluminum according to a preset proportion to enable the total metal concentration in the solution A to be 1.0 mol/L; preparing a sodium hydroxide solution B with the hydroxide radical concentration of 5.0 mol/L; preparing an ammonia water solution C with the ammonia radical concentration of 5.0 mol/L;

(2) adding a proper amount of pure water and ammonia water solution into a main reaction device to serve as base solution, enabling the concentration of ammonia radicals in the base solution to be 1.0mol/L, stirring, and adding NCA ternary precursor crystal seeds with D50 being 9.5 mu m;

(3) sealing the main reaction device, introducing nitrogen as protective gas, simultaneously pumping the solution A, the solution B and the solution C into the main reaction device in proportion, controlling the stirring speed to be 300rpm, controlling the temperature to be 50 ℃ and the pH value to be 12.5, and when the liquid level of the main reaction device is full, enabling the slurry in the main reaction device to overflow to a first overflow device communicated with the main reaction device;

(4) when the slurry overflows to a 75-80% volume liquid level of a first overflow device, sealing the first overflow device, introducing nitrogen as protective gas, simultaneously pumping the solution A, the solution B and the solution C into the first overflow device in proportion, controlling the stirring speed to be 80rpm, the temperature to be 40 ℃, and the pH value to be 11.5, gradually growing ternary precursor particles in the first overflow device along with the continuous entering of the solution A, the solution B and the solution C, discharging mother liquor by using a filtering device when the liquid level of the first overflow device is full, continuously remaining the ternary precursor particles in the first overflow device for growing until the particle size meets the requirement, stopping feeding, completely transferring materials in the first overflow device, entering a post-treatment stage, and emptying the first overflow device for later use; the total reaction time of the ternary precursor particles in the first overflow device was 12 hours.

(6) when the slurry overflows to the 75-80% volume liquid level of the second overflow device, the slurry in the main reaction device begins to overflow to other overflow devices communicated with the main reaction device, and when the slurry overflows to the 75-80% volume liquid level of other overflow devices, the other overflow devices are produced by the same method as the first overflow device in the step (4);

(7) when the other overflow devices are full of liquid, the slurry in the main reaction device begins to overflow to the first overflow device communicated with the main reaction device, and returns to the step (4) for production, and the steps are repeated in a circulating mode.

Embodiment 6:

(1) preparing a sulfate solution A of nickel, cobalt and aluminum according to a preset proportion to enable the total metal concentration in the solution A to be 1.8 mol/L; preparing a sodium hydroxide solution B with the hydroxide radical concentration of 12.0 mol/L; preparing an ammonia water solution C with the ammonia radical concentration of 10.0 mol/L;

(2) adding a proper amount of pure water and ammonia water solution into a main reaction device to serve as base solution, enabling the concentration of ammonia radicals in the base solution to be 0.3mol/L, stirring, and adding NCA ternary precursor crystal seeds with the D50 being 11.0 mu m;

(3) sealing the main reaction device, introducing nitrogen as protective gas, simultaneously pumping the solution A, the solution B and the solution C into the main reaction device in proportion, controlling the stirring speed to be 150rpm, controlling the temperature to be 70 ℃, controlling the pH value to be 11.5, and when the liquid level of the main reaction device is full, enabling the slurry in the main reaction device to overflow to a first overflow device communicated with the main reaction device;

(4) when the slurry overflows to a 75-80% volume liquid level of a first overflow device, sealing the first overflow device, introducing nitrogen as protective gas, simultaneously pumping the solution A, the solution B and the solution C into the first overflow device in proportion, controlling the stirring speed to be 120rpm, the temperature to be 60 ℃, and the pH value to be 10.5, gradually growing ternary precursor particles in the first overflow device along with the continuous entering of the solution A, the solution B and the solution C, discharging mother liquor by using a filtering device when the liquid level of the first overflow device is full, continuously remaining the ternary precursor particles in the first overflow device for growing until the particle size meets the requirement, stopping feeding, completely transferring materials in the first overflow device, entering a post-treatment stage, and emptying the first overflow device for later use; the total reaction time of the ternary precursor particles in the first overflow device was 12 hours.

After solid-liquid separation, the obtained ternary precursor slurry is washed by pure water for 5 times and dried for 10 hours at 110 ℃. Screening, demagnetizing, packaging and warehousing.

Embodiment 7:

(1) preparing a sulfate solution A of nickel, cobalt and aluminum according to a preset proportion to ensure that the total metal concentration in the solution A is 2.0 mol/L; preparing a sodium hydroxide solution B with the hydroxide radical concentration of 11.0 mol/L; preparing an ammonia water solution C with the ammonia radical concentration of 11.0 mol/L;

(2) adding a proper amount of pure water and ammonia water solution into a main reaction device to serve as base solution, enabling the concentration of ammonia radicals in the base solution to be 0.4mol/L, stirring, and adding NCA ternary precursor crystal seeds with the D50 being 11.0 mu m;

(3) sealing the main reaction device, introducing nitrogen as protective gas, simultaneously pumping the solution A, the solution B and the solution C into the main reaction device in proportion, controlling the stirring speed to be 250rpm, controlling the temperature to be 40 ℃ and controlling the pH value to be 11.7, and when the liquid level of the main reaction device is full, enabling the slurry in the main reaction device to overflow to a first overflow device communicated with the main reaction device;

(4) when the slurry overflows to a 75-80% volume liquid level of a first overflow device, sealing the first overflow device, introducing nitrogen as protective gas, simultaneously pumping the solution A, the solution B and the solution C into the first overflow device in proportion, controlling the stirring speed to be 140rpm, the temperature to be 40 ℃, and the pH value to be 10.7, gradually growing ternary precursor particles in the first overflow device along with the continuous entering of the solution A, the solution B and the solution C, discharging mother liquor by using a filtering device when the liquid level of the first overflow device is full, continuously remaining the ternary precursor particles in the first overflow device for growing until the particle size meets the requirement, stopping feeding, completely transferring materials in the first overflow device, entering a post-treatment stage, and emptying the first overflow device for later use; the total reaction time of the ternary precursor particles in the first overflow device was 15 hours.

Embodiment 8:

(1) preparing a sulfate solution A of nickel, cobalt and aluminum according to a preset proportion to ensure that the total metal concentration in the solution A is 2.0 mol/L; preparing a potassium hydroxide solution B with the hydroxide radical concentration of 10.0 mol/L; preparing an ammonia water solution C with the ammonia radical concentration of 12.0 mol/L;

(2) adding a proper amount of pure water and ammonia water solution into a main reaction device to serve as base solution, enabling the concentration of ammonia radicals in the base solution to be 0.1mol/L, stirring, and adding NCA ternary precursor crystal seeds with D50 being slightly smaller than 12.0 mu m;

(3) sealing the main reaction device, introducing nitrogen as protective gas, simultaneously pumping the solution A, the solution B and the solution C into the main reaction device in proportion, controlling the stirring speed to be 280rpm, controlling the temperature to be 45 ℃ and controlling the pH value to be 12.1, and when the liquid level of the main reaction device is full, enabling the slurry in the main reaction device to overflow to a first overflow device communicated with the main reaction device;

(4) when the slurry overflows to a 75-80% volume liquid level of a first overflow device, sealing the first overflow device, introducing nitrogen as protective gas, simultaneously pumping the solution A, the solution B and the solution C into the first overflow device in proportion, controlling the stirring speed to be 250rpm, the temperature to be 40 ℃, and the pH value to be 11.1, gradually growing ternary precursor particles in the first overflow device along with the continuous entering of the solution A, the solution B and the solution C, discharging mother liquor by using a filtering device when the liquid level of the first overflow device is full, continuously remaining the ternary precursor particles in the first overflow device for growing until the particle size meets the requirement, stopping feeding, completely transferring materials in the first overflow device, entering a post-treatment stage, and emptying the first overflow device for later use; the total reaction time of the ternary precursor particles in the first overflow device was 20 hours.

Embodiment 9:

(1) preparing a sulfate solution A of nickel, cobalt and aluminum according to a preset proportion to ensure that the total metal concentration in the solution A is 2.0 mol/L; preparing a potassium hydroxide solution B with the hydroxide radical concentration of 9.0 mol/L; preparing an ammonia water solution C with the ammonia radical concentration of 9.5 mol/L;

(2) adding a proper amount of pure water and ammonia water solution into a main reaction device to serve as base solution, enabling the concentration of ammonia radicals in the base solution to be 0.6mol/L, stirring, and adding NCA ternary precursor crystal seeds with the D50 being 11.5 mu m;

(3) sealing the main reaction device, introducing helium gas as protective gas, simultaneously pumping the solution A, the solution B and the solution C into the main reaction device in proportion, controlling the stirring speed to be 300rpm, the temperature to be 55 ℃, and the pH value to be 12.0, and when the liquid level of the main reaction device is full, enabling the slurry in the main reaction device to overflow to a first overflow device communicated with the main reaction device;

(4) when the slurry overflows to a liquid level of 75-80% of the volume of the first overflow device, sealing the first overflow device, introducing helium as a protective gas, simultaneously pumping the solution A, the solution B and the solution C into the first overflow device in proportion, controlling the stirring speed to be 130rpm, the temperature to be 50 ℃, and the pH value to be 11.0, gradually growing ternary precursor particles in the first overflow device along with the continuous entering of the solution A, the solution B and the solution C, discharging a mother liquor by using a filtering device when the liquid level of the first overflow device is full, continuously remaining the ternary precursor particles in the first overflow device for growing until the particle size meets the requirement, stopping feeding, completely transferring the materials in the first overflow device, entering a post-treatment stage, and emptying the first overflow device for later use; the total reaction time of the ternary precursor particles in the first overflow device was 9 hours.

Embodiment 10:

solution a is a nitrate solution, and the rest is the same as embodiment 1.

Embodiment 11:

the solution a is a chloride solution, and the rest is the same as embodiment 1.

Embodiment 12:

the metal ion in the solution a is NCM, the ternary precursor seed crystal is NCM, and the rest is the same as embodiment 1.

Embodiments 13 to 15:

repeat embodiment 1, 3 times.

Embodiments 16 to 18:

repeat embodiment 9, 3 times.

Comparative example 1:

the rotating speed in the step (4) is 180 rpm. The other conditions were the same as in embodiment 1.

Comparative example 2:

the pH in the step (4) is the same as that in the step (3), and the other conditions are the same as those in embodiment 1.

Comparative example 3:

the rotating speed in the step (4) is 180 rpm. The other conditions were the same as in embodiment 9.

Comparative example 4:

the pH in the step (4) is the same as that in the step (3), and the other conditions are the same as those in embodiment 9.

After the wide-distribution and micro-powder-free ternary precursor slurry obtained in the embodiments 1 to 9 and the comparative examples 1 to 4 was subjected to solid-liquid separation, pure water washing and drying, a sample was taken and subjected to SEM and laser particle size tests. Wherein Table 1 shows the results of the laser particle size tests of embodiments 1 to 9 and comparative examples 1 to 4;

wherein, the laser particle size testing instrument is MS3000, the testing medium is water, and the refractive index of the particles is 2.42.

The wide-distribution, fine powder-free ternary precursor obtained in embodiments 1 to 9, 10 to 12, and 13 to 18 has a good stability, a wide distribution, and no fine powder.

In the laser particle size test data of comparative example 1, the existence of fine particles is not observed, but the SEM electron micrograph shows that the occurrence of cracks can be obviously observed on the surface of the spherical precursor, which indicates that the rotation speed has a great influence on the synthesis of the precursor in the embodiment of the present invention, and in the present invention, the collision between precursor particles is aggravated due to the high rotation speed, so that spherical cracks occur.

The laser particle size test data in comparative example 2 shows obvious data peak values at 1 micron and below, which indicates that the precursor obtained by the method in comparative example 2 has a certain amount of micropowder particles. It is shown that, although the pH at the time of nucleation in the main reactor and the pH at the time of growth in the overflow apparatus (in this case, nucleation is suppressed) differ by only 1 in the embodiment of the present invention, the present invention has a great effect of suppressing the formation of the entire precursor fine powder.

In the laser particle size test data of comparative example 3, the presence of fine particles was not observed, but SEM electron micrographs thereof showed that the occurrence of cracks was clearly observed on the surface of the precursor.

The laser particle size test data in comparative example 4 shows a clear data peak value at 1 micron and below, which indicates that the precursor obtained by the method in comparative example 4 has a certain amount of micropowder particles.

As can be seen from the data of the embodiment, the comparative example and the attached drawings, the wide-distribution ternary precursor without the micro powder obtained by the method has no existence of the micro powder. The preparation method has the advantages of high production efficiency, short production time, acceptable cost interval, good product stability, good repeatability, wide particle size distribution, no micro powder and accurate and controllable particle size. The method is suitable for continuous production operation, high in production efficiency, high in productivity and low in production cost, can prepare the wide-distribution micro-powder-free ternary precursor, has very important significance for improving the safety performance, the cycle performance, the service life and the like of the battery, and effectively solves the related problems of high cost, low production efficiency and the like of micro powder removal or micro powder existing in ternary precursor particles in the current preparation method.

Reaction unit of no miropowder ternary precursor of wide distribution includes:

the device comprises a main reaction device 100, wherein three main feed inlets 101 and two overflow outlets 102 are arranged on the main reaction device 100;

a main stirring device 103 connected with the main reaction device 100 and used for stirring in the main reaction device 100 during the reaction of the ternary precursor;

a first overflow device 200 connected to the main reaction device 100 through a first overflow pipe 300, wherein the first overflow pipe 300 is provided with a first overflow valve 301, and the first overflow pipe 300 is opened or closed to control the slurry in the main reaction device 100 to overflow to the first overflow device 200 through the first overflow pipe 300;

the first stirring device 203 is connected with the first overflow device 200 and is used for stirring in the first overflow device 200 during the ternary precursor reaction;

the first overflow device 200 is further provided with a first discharge opening 202 and three first feed openings 201;

the second overflow device 210 is connected with the main reaction device 100 through a second overflow pipe 310, and a second overflow valve 311 is arranged on the second overflow pipe 310 and is opened or closed to control the slurry in the main reaction device 100 to overflow to the second overflow device 210 through the second overflow pipe 310;

and a second stirring device 213 connected to the second overflow device 210, for stirring in the second overflow device 210 during the ternary precursor reaction.

The second overflow means 210 is further provided with a second discharge opening 212 and three second feed openings 211.

In some embodiments of the present invention, the opposite positions of the two ends of the first overflow conduit 300 are arranged in a high-low manner, wherein one end of the main reaction device 100 connected with the first overflow conduit 300 is higher than the other end of the main reaction device 200 connected with the first overflow conduit 300. So that the slurry in the main reaction unit 100 overflows into the first overflow unit 200 through the first overflow line 300.

In some embodiments of the present invention, a filtering device 400 is further disposed in the first overflow device 200 and the second overflow device 210, and is used for filtering the mother liquor in the first overflow device 200 and the second overflow device 210, so as to increase the reaction concentration of the slurry in the first overflow device 200 and the second overflow device 210. Promoting the growth of the ternary precursor, inhibiting the nucleation of the ternary precursor under proper conditions and avoiding the existence of micro powder with the granularity less than 1 mu m in the final product.

In some embodiments of the present invention, the number of the first feed openings 201 is at least three. In general, the number of the first feed ports is set to three in consideration of the fact that the material synthesized into the ternary system facilitates the transport of the raw material.

Of course, in some embodiments of the present invention, the number of the first feeding holes may also be four or more, and does not affect the implementation of the technical solution of the present invention. It should also be mentioned that the number of the feed inlets in the present invention may be one, and at this time, the raw materials of the ternary system only need to be added through different pipelines through one feed inlet.

In some embodiments of the present invention, the number of the second feed ports 211 is at least three. Here, considering that the material synthesized as a ternary system facilitates the transport of the raw material, the number of the second feed ports is set to three. Of course, the number of the second feed openings may also be four or more, or the number of the second feed openings may also be one, which does not affect the implementation of the technical solution of the present invention.

In some embodiments of the invention, the number of main feed openings 101 is at least three. Here, considering that the material synthesized as a ternary system facilitates the transport of the raw material, the number of the main feed ports is set to three. Of course, the number of the main feed inlets may also be four or more, or the number of the main feed inlets may also be one, which does not affect the implementation of the technical solution of the present invention.

In some embodiments of the present invention, the number of the main feed openings, the number of the first feed openings, and the number of the second feed openings are the same.

In some embodiments of the present invention, the filtering device 400 is located at a position near, but not in contact with, the inner sidewall at an upper portion of the first overflow device 200 or/and the second overflow device 210.

In some embodiments of the invention, the filtration unit 400 is connected to a mother liquor collection tank 403 via a mother liquor transfer conduit 401. And, an air operated diaphragm pump 402 is further disposed between the mother liquor conveying pipeline 401 and the mother liquor collecting tank 403 to provide a negative pressure, so that the mother liquor in the first overflow device 200 or/and the second overflow device 210 is filtered out from the mother liquor conveying pipeline 401.

In some embodiments of the present invention, a pressure regulating valve 404 is also provided between the pneumatic diaphragm pump 402 and the filter apparatus 400. The negative pressure in the filtering device is adjusted, and the filtering speed of the mother liquor in the first overflow device and/or the second overflow device is controlled.

In some embodiments of the invention, a discharge port is further provided on the main reaction unit to facilitate cleaning of the main reaction unit when the main reaction unit is shut down and repaired or the process is changed greatly. In some embodiments of the present invention, the discharge opening is disposed at the bottom of the main reaction device, so as to prevent slurry from remaining in the main reaction device during the cleaning process.

(1) preparing a mixed salt solution A to ensure that the total metal concentration in the solution A is 1.0-2.0 mol/L; preparing a solution B to ensure that the concentration of hydroxyl in the solution B is 5.0-12.0 mol/L; preparing an ammonia water solution C with the ammonia radical concentration of 5.0-12.0 mol/L;

(3) sealing the main reaction device 100, introducing protective gas I, simultaneously pumping the solution A, the solution B and the solution C into the main reaction device 100 according to the proportion, stirring, controlling the temperature at 40-70 ℃ and the pH value at 11.5-12.5, and when the liquid level of the main reaction device 100 is full, enabling the slurry in the first overflow device 200 to begin to overflow to the first overflow device 200 communicated with the first overflow device 200;

(4) when the slurry overflows to a 75-80% volume liquid level of the first overflow device 200, sealing the first overflow device 200, introducing a second protective gas, simultaneously pumping the solution A, the solution B and the solution C into the first overflow device 200 in proportion, stirring, controlling the temperature to be 40-70 ℃, controlling the pH value to be 1.0 less than that of the main reaction device 100, discharging the mother liquid by using a filtering device 400 when the liquid level of the first overflow device 200 is full, continuously remaining the ternary precursor particles in the first overflow device 200 for growth until the particle size meets the requirement, stopping feeding, completely transferring the materials in the first overflow device 200, entering a post-treatment stage, and emptying the first overflow device 200 for later use;

(5) when the first overflow device 200 is full of liquid, closing the first overflow valve 301, and opening the second overflow valve 311, at this time, the slurry in the main reaction device 100 begins to overflow to the second overflow device 210 communicated with the main reaction device, and when the slurry overflows to the 75-80% volume liquid level of the second overflow device 210, the second overflow device 210 is produced according to the same method as the first overflow device 200 in the step (4);

(6) when the liquid level of the second overflow device 210 is full, the slurry in the main reaction device 100 begins to overflow to other overflow devices or the first overflow device 200 communicated with the main reaction device, and when the slurry overflows to 75-80% volume liquid level of the other overflow devices or the first overflow device 200, the other overflow devices or the first overflow device 200 are produced according to the same method as the first overflow device 200 in the step (4), and the steps are repeated in a circulating mode.

In the description of the present invention, it is to be understood that the terms "first", "second", and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicit indication of the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the feature. In the description of the present invention, unless otherwise explicitly specified or limited, the terms "connected" and the like are to be construed broadly, e.g., as fixed or removable connections or integral parts; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the description of the present specification, reference to the terms "one embodiment," "some embodiments," "an example," "a specific example" or "some examples" or the like means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the various embodiments or examples and features of the various embodiments or examples described in this specification can be combined and combined by those skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and not to be construed as limiting the present invention, and those skilled in the art can make changes, modifications, substitutions and alterations to the above embodiments within the scope of the present invention.

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Production device and method of wide-distribution micro-powder-free ternary precursor

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