Continuous production process and system for battery material precursors with controllable particle distribution

Abstract

The present invention discloses a continuous production process and system of battery material precursors capable of controlling particle distribution, the system comprising N reactors connected in series in sequence, each reaction chamber being connected to a nucleation reactor, and each nucleation reactor and each reactor body being provided with a stirring device. The present invention proposes a new continuous production mode, in which a smaller reactor is used to continuously synthesize precursor nuclei, and then the precursor nuclei are continuously injected into a series of larger reactors connected in series; the precursor nuclei crystallize and grow on the surface of the precursor particles in the reactor, so that the precursor particles gradually grow in the series growth reactors; this scheme has a continuous operation process, a high degree of automation, low equipment investment, low operating cost, a narrow distribution of precursor particle size, and stable product quality, which meets the needs of large-scale chemical production, and has great advantages in the large-scale production process of battery positive electrode material precursors.

Description

Technical Field

[0001] The present invention relates to the technical field of battery material preparation, and in particular to a continuous production process and system for a battery positive electrode material precursor capable of controlling particle size distribution. Background Art

[0002] The NCA / NCM / NCMA ternary precursor of the positive electrode material of lithium-ion batteries refers to a co-precipitated compound of nickel, cobalt, and aluminum (manganese) hydroxide, which is the main raw material for the production of nickel cobalt, aluminum (manganese) acid ternary or quaternary positive electrode materials. The preparation of positive electrode materials usually involves first synthesizing the precursor, then mixing the precursor with a lithium salt (lithium carbonate or lithium hydroxide), and calcining it multiple times at high temperature to obtain the positive electrode material for lithium-ion batteries. The value of the ternary or quaternary precursor can account for more than 50% of the value of the positive electrode material, and the proportion of the positive electrode material in the cost of lithium battery materials is as high as about 40%. The performance of the ternary positive electrode material is directly related to the physicochemical properties of the precursor, so it is crucial to achieve controllable preparation of the ternary precursor.

[0003] In recent years, single crystal and high nickel content have become the main development direction of positive electrode materials. Different battery material factories have different requirements for the composition and physical and chemical properties of materials. From this perspective, developing a continuous synthesis process that can produce precursors of different compositions and precisely control the morphology of the precursors is the future development direction.

[0004] At present, the mainstream ternary precursor production process adopts intermittent synthesis. The advantage of intermittent synthesis is that it has a mature amplification path, simple operation, and has been widely used. However, the disadvantages of intermittent synthesis are unstable product quality, difficulty in achieving automatic control, low production efficiency (high equipment investment and labor costs), high energy consumption, resulting in high final product costs. Continuous synthesis, which corresponds to intermittent synthesis, is easy to achieve automatic control, has stable product quality and output, high production efficiency (low equipment investment, labor costs and energy consumption), and low product cost. It is the mainstream chemical production method. Therefore, if a continuous synthesis process for ternary precursors can be developed, the drawbacks of existing intermittent synthesis can be avoided, and stable and efficient production of high-quality precursors can be achieved, while significantly reducing product costs, which is extremely economical.

[0005] The chemical formula of the cathode material precursor can be Ni x Co y Mn z Al w (OH) 2x+2y+2z+3wIndicates. When the value of x is greater than 0.6, we call it a high-nickel material. Typically, when x=0.8, y=0.1 and z=0.1, it is called a high-nickel NCM811 material. The preparation process of the positive electrode material precursor usually includes the following steps: three feeds are mixed in a stirred tank reactor, and one feed contains salts of the above-mentioned metals (nickel, cobalt, manganese, aluminum), such as sulfates, nitrates, etc. A typical mixed solution is nickel sulfate, cobalt sulfate, manganese sulfate or aluminum sulfate, and its proportion can be formulated according to the composition of the target positive electrode material. One feed contains an alkaline precipitant, usually sodium hydroxide or sodium carbonate, or a mixture thereof; the third is ammonia water as a complexing agent. The three feeds are simultaneously input into the stirred tank reactor to form a precipitate, and a ternary precursor is obtained after filtration, washing and drying. The ternary precursor usually presents a spherical morphology (secondary sphere) formed by a combination of lamellar crystals (primary particles).

[0006] In a typical precursor preparation process, at the beginning of the reaction, the precipitate formed immediately after the three streams of materials are mixed can be called a "crystal nucleus", which is usually nanometer-sized. After the crystal nucleus is formed, the three streams of materials added subsequently will precipitate on the surface of the existing crystal nucleus, causing the crystal nucleus to gradually grow. This step is what is called the crystal growth step in crystallography. With the continuous addition of fresh raw materials, the tiny crystal nucleus gradually grows into spherical precursor particles. By controlling the formula and synthesis conditions, the sphericity, particle size, tap density and other indicators of the precursor particles can be controlled.

[0007] According to the requirements of downstream, the particle size, particle size distribution and morphology of the precursor are the most important control indicators. Compared with other irregular morphologies, spherical particles have a higher tap density and can obtain a higher energy density. Generally speaking, the particle size distribution of particles obtained by intermittent precipitation is relatively narrow, while the particle distribution obtained by continuous precipitation is relatively wide. Usually, the particle size of the precursor particles can be controlled between 1-15 microns. Small-particle positive electrode materials have faster charge and discharge rates and are suitable for power batteries; while large-particle positive electrode materials are suitable for energy batteries due to their higher tap density (i.e. battery capacity density). When the diameter of the precursor particles is small, the subsequent reaction with lithium carbonate or lithium hydroxide is faster, and the required roasting time is shorter; when the diameter of the precursor particles is larger, a longer roasting time is required. If the particle size distribution of the precursor is wide, it may cause small particles to be overburned, while large particles have not yet reached the degree of complete conversion, thus reducing the performance of the battery material.

[0008] The preparation of battery positive electrode material precursors by precipitation is the current mainstream industrial synthesis method. China currently accounts for about 90% of the battery positive electrode precursor market, but its production process has not yet been continuous, and the quality of the product depends on the experience of the operator, or there is a large fluctuation between batches. The reason is that the co-precipitation process is relatively long, there are many parameters that need to be controlled, the control is relatively difficult, and the control accuracy requirements are relatively high. In addition, since there are three or more metal salts that need to be precipitated together, such as nickel-cobalt-manganese, including nickel-cobalt-aluminum. Due to the large difference in the concentration product constants of manganese and nickel-cobalt, aluminum and nickel-cobalt, during the co-precipitation process, some components may precipitate first, resulting in uneven distribution of active components, thereby affecting the quality of the ternary precursor material. Since precipitants and complexing agents need to be introduced during the precipitation process, a large amount of high-salt and ammonia-containing wastewater will be generated, so the stability of the precipitation process, the reliability of the process, and the circulation of ammonia are all expected to have a continuous industrial production process to correspond.

[0009] Although the current production capacity of battery cathode materials and precursors has reached the level of millions of tons, there is no process that can produce precursors continuously, stably and efficiently. The production capacity, quality, stability and efficiency of precursors have always been challenges in the industry. Summary of the invention

[0010] The technical problem to be solved by the present invention is to provide a continuous production process and system for battery material precursors with controllable particle size distribution in view of the deficiencies in the above-mentioned prior art.

[0011] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows: In a first aspect of the present invention, a continuous production system of a battery positive electrode material precursor capable of controlling particle size distribution is provided, comprising N reaction chambers connected in series in sequence, each reaction chamber is connected to a nucleation kettle, and each reaction chamber and each reactor is provided with a stirring device;

[0012] Wherein, N is an integer greater than 6.

[0013] Preferably, the ratio of the volume of the reaction chamber to the volume of the nucleation reactor is 5-1000.

[0014] Preferably, except for the first reaction chamber, the feed of each of the remaining reaction chambers includes at least two streams: at least one stream comes from the discharge of the previous reaction chamber, and at least one stream comes from the discharge of the correspondingly connected nucleation reactor.

[0015] Preferably, each reaction chamber is independently connected to a nucleation kettle, or a plurality of adjacent reaction chambers are connected in parallel to a nucleation kettle.

[0016] Preferably, the N reaction chambers are formed by N growth kettles connected in series, and a stirring device is provided in each reaction kettle.

[0017] Preferably, N reaction chambers are placed in a tubular reactor, that is, the tubular reactor is partitioned by partitions to form N reaction chambers separated in sequence and arranged in sequence along the axial direction of the reactor, and the material can flow in sequence along the N series-connected reaction chambers, and N stirring devices are placed in the N reaction chambers and share a stirring shaft.

[0018] In a second aspect of the present invention, a continuous production process of a battery positive electrode material precursor capable of controlling particle distribution is provided, wherein the system as described above is used to produce the battery positive electrode material precursor, and the process is:

[0019] Raw materials for preparing battery material precursors are added into each nucleation reactor, and a suspension of precursor crystal nuclei is formed by heating and stirring;

[0020] Each nucleation reactor transports the suspension of the precursor nuclei to the corresponding connected reaction chamber, reacts under heating and stirring, and the output in each reaction chamber is transported to the adjacent next-level reaction chamber along the connection sequence.

[0021] Preferably, the reaction conditions in the nucleation reactor are: pH 11-12, reaction temperature 20-80°C;

[0022] The reaction conditions in the reaction chamber are: pH 11-12, and reaction temperature 20-80°C.

[0023] Preferably, each reaction chamber is independently connected to a nucleation kettle, the volume of the nucleation kettle is 1-10L, and the volume of the reaction chamber is 5-10000L.

[0024] Preferably, the raw materials for preparing the battery material precursor include a mixed salt prepared according to the proportion of the battery material precursor and an alkali used as a precipitant, and the mixed salt includes a salt containing nickel, cobalt and manganese;

[0025] The molar concentration of the mixed salt in the raw materials added to the nucleation reactor is 1-4 mol / L; the molar concentration of the alkali is 2-8 mol / L, and the molar ratio of the alkali to the mixed salt is 0.5-2:3-12.

[0026] The beneficial effects of the present invention are:

[0027] The present invention provides a continuous production process and system for battery material precursors capable of controlling particle size distribution. The present invention completely separates the nucleation process and the growth process in the precursor process, and continuously provides precursor crystal nuclei through a relatively small nucleation reactor; then the crystal nucleus suspension prepared by the nucleation reactor is continuously added into a series of growth reactors connected in series, and the crystal nuclei of the precursor crystal grow on the surface of the precursor particles in the growth reactor, so that the precursor particles gradually grow in the series-connected growth reactors, and finally the controllable synthesis of precursor particles with a narrow particle size distribution can be achieved.

[0028] The present invention proposes a new continuous production mode, which adopts a smaller reactor (nucleation kettle) to continuously synthesize precursor crystal nuclei, and then continuously injects the precursor crystal nuclei into a larger reactor (growth kettle) connected in series; these precursor crystal nuclei grow and crystallize on the surface of precursor particles in the growth kettle, which promotes the growth of precursor particles; this scheme has a continuous operation process, a high degree of automation, less equipment investment, low operating cost, and stable product quality, which meets the needs of large-scale chemical production, and has great advantages in the production process of large-scale precursors. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of a continuous production system of a battery material precursor capable of controlling particle distribution according to the present invention;

[0030] Figure 2 It is a schematic structural diagram of another continuous production system of battery material precursors capable of controlling particle distribution according to the present invention;

[0031] Figure 3 It is a schematic structural diagram of another continuous production system of battery material precursors capable of controlling particle distribution according to the present invention;

[0032] Figure 4 It is a schematic structural diagram of another continuous production system of battery material precursors capable of controlling particle distribution according to the present invention;

[0033] Figure 5 It is a schematic structural diagram of another continuous production system of battery material precursors capable of controlling particle distribution according to the present invention;

[0034] Figure 6 This is a morphology diagram of the precursor product prepared in Example 1;

[0035] Figure 7 This is a morphology diagram of the precursor product prepared in Example 2. DETAILED DESCRIPTION

[0036] The present invention is further described in detail below in conjunction with embodiments so that those skilled in the art can implement the invention with reference to the description.

[0037] It should be understood that the terms such as “having”, “including” and “comprising” used herein do not exclude the existence or addition of one or more other elements or combinations thereof.

[0038] The test methods used in the following examples are conventional methods unless otherwise specified. The materials and reagents used in the following examples are all commercially available unless otherwise specified. In the following examples, if no specific conditions are specified, the experiments were carried out under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used, if the manufacturer is not specified, are all conventional products that can be purchased commercially.

[0039] The present invention provides a continuous production system of battery material precursors capable of controlling particle distribution, comprising N reactors connected in series, each reactor being connected to a nucleation reactor, and each nucleation reactor and each reactor being provided with a stirring device;

[0040] Wherein, N is an integer greater than 6.

[0041] In a preferred embodiment, the ratio of the volume of the reaction kettle to the volume of the nucleation kettle is 5 to 1000.

[0042] In a preferred embodiment, except for the first reactor, the feed of each of the remaining reaction chambers includes at least two streams: at least one stream comes from the discharge of the previous reactor, and at least one stream comes from the discharge of the correspondingly connected nucleation reactor.

[0043] In a preferred embodiment, each reactor is independently connected to a nucleation reactor, or a plurality of adjacent reactors are connected in parallel to a nucleation reactor.

[0044] In a preferred embodiment, N reaction chambers are formed by N growth kettles connected in series, and a stirring device is provided in each reaction kettle.

[0045] In a preferred embodiment, N reaction chambers can be placed in a tubular reactor, that is, the tubular reactor is partitioned by partitions to form N reaction chambers separated in sequence and arranged in sequence along the axial direction of the reactor, and the material can flow in sequence along the N series-connected reaction chambers, and N stirring devices are placed in the N reaction chambers and share a stirring shaft.

[0046] In a preferred embodiment, a membrane filtration unit is disposed at the outlet of the last reactor to remove the solvent in the reactor and increase the solid content, thereby improving the productivity of the reactor.

[0047] The present invention also provides a continuous production process of a battery positive electrode material precursor capable of controlling particle size distribution, which uses the above system to produce the battery material precursor, and the process is:

[0048] Raw materials for preparing battery material precursors are added into each nucleation reactor, and a suspension of precursor crystal nuclei is formed by heating and stirring;

[0049] Each nucleation reactor transports the suspension of the precursor nuclei to the corresponding connected reactor for reaction under heating and stirring, and the output from each reactor is transported to the adjacent next-stage reactor in the connection sequence.

[0050] In a preferred embodiment, the reaction conditions in the nucleation reactor are: pH 11-12, and reaction temperature 30-70°C.

[0051] In a preferred embodiment, the reaction conditions in the reactor are: pH 11-12, and reaction temperature 40-60°C.

[0052] In a preferred embodiment, each reactor is independently connected to a nucleation reactor, the volume of the nucleation reactor is 1-10L, and the volume of the reactor is 5-10000L.

[0053] In a preferred embodiment, the raw materials for preparing the battery material precursor include a mixed salt prepared according to the battery material precursor in a proportion and an alkali used as a precipitant, and the mixed salt includes a salt containing nickel, cobalt, and manganese;

[0054] The molar concentration of the mixed salt in the raw materials added to the nucleation reactor is 1-4 mol / L; the molar concentration of the alkali is 2-8 mol / L, and the molar ratio of the alkali to the mixed salt is 0.5-2:3-12.

[0055] In a preferred embodiment, the present invention is mainly used for a continuous production process of a mixed salt containing nickel, cobalt, manganese, aluminum or one or more of the following elements (Ti, Zr, Nb, W, B, P) and a precipitant (hydroxide, carbonate, etc.) to form a hydroxide or carbonate precipitation process. This precipitation product can be used as a precursor of a positive electrode material for a lithium ion battery or a sodium ion battery. More specifically, the present invention provides a method for the continuous production of a battery positive electrode material precursor. The method is carried out in the following order: raw materials (salts and precipitants, etc.) are added to one or more relatively small continuous reaction kettles (referred to as nucleation kettles), and a suspension of precursor crystal nuclei (which can be hydroxides or carbonates) is formed in the nucleation kettle under vigorous stirring. The crystal nucleus suspension is continuously added to one or several fully mixed kettles in series (referred to as growth kettles), and the crystal nuclei of the precursor crystals grow on the surface of the precursor particles in the growth kettle, so that the precursor particles gradually grow in the series of growth kettles. The number of fully mixed kettles used as precursor growth is greater than or equal to 6. After a certain period of growth, precursor particles (hydroxide or carbonate) that meet the technical requirements can be obtained. The present invention completely separates the nucleation process and the growth process in the precursor process, and continuously provides precursor nuclei through a smaller nucleation reactor; then the nucleus suspension prepared by the nucleation reactor is continuously added to a series of growth reactors connected in series, and the precursor particles are gradually grown in the growth reactor, and finally the controllable synthesis of precursor particles with a narrow particle size distribution is achieved. Its principle is as follows: Figure 1 In addition, a membrane filtration unit can be arranged at the outlet of the growth reactor to remove the solvent in the growth reactor, increase the solid content, and thus improve the productivity of the growth reactor.

[0056] Generally speaking, in order to obtain particles with a single (narrow) particle size distribution, it is necessary to strictly control the growth time of the particles during the precipitation process, that is, the same growth time is easy to obtain particle products with a narrow particle size distribution. For the precipitation process of forming a ternary precursor, there are generally three types. One is to place a precipitant (alkali or carbonate, etc.) or salt in a reactor as a base material, and then gradually add the corresponding salt or alkali to form a precipitate. This synthesis method causes the growth time of the first precipitated particles and the subsequent precipitated particles in the reactor to be different, resulting in a wider product particle size distribution, that is, the first formed precipitate has the longest growth time and the largest particle size; while the precipitate formed by the last added raw material has the shortest growth time and the smallest particle size. The second method is to add salt and the corresponding precipitant to the precipitation kettle at the same time (co-precipitation method), so that the growth time of the first formed precipitate particles during the precipitation process is longer than that of the subsequent formed precipitate particles, which will also form a wider particle size distribution, that is, the particle size of the first formed precipitate particles will be larger. The above two syntheses are intermittent syntheses. The last form is continuous precipitation, that is, the salt and precipitant are continuously added to the reactor (growth reactor) at a fixed feed rate to form precipitation, and at the same time, the materials in the reactor leave the reactor at the same discharge rate (overflow reactor). The residence time of the materials leaving the reactor in the reactor is not the same, but there is a wide distribution, which also leads to a wide distribution of product particle size.

[0057] In view of the problem of wide particle size distribution of ternary precursors at present, the present invention adopts a method of completely separating nucleation and crystal growth to achieve precise control of product particle size. That is, salt and precipitant are added simultaneously in the nucleation kettle, and the precipitation reaction is completed in a relatively short time to form a large number of nanoscale crystal nuclei (or precipitation precursors). The reaction time of the nucleation process must be very short to avoid the growth of the crystal nuclei, thereby obtaining crystal nuclei with narrow particle size distribution. Then the crystal nuclei are added to a series of crystal growth kettles in series, so that the crystal nuclei are crystallized and grown on the surface of the precursor particles in the growth kettle, so that the particles of the precursor gradually grow into precursor particles in the series growth kettle. To obtain precursor particles with narrow particle size distribution, an effective strategy is to use multiple reactors in series to obtain a narrower particle size distribution. In the case of multiple reactors in series (n>6), the reaction process is close to a tubular reactor (plug flow), and the obtained particle distribution is relatively narrow, which meets the subsequent use requirements. In large-scale production processes, as the volume of the reactor increases, the stirring power in the reactor increases significantly, and it is difficult to enlarge the reactor. Therefore, the present invention adopts a small reactor (nucleation reactor) to prepare the nanocrystalline nuclei required for the reaction; then the nanocrystalline nuclei are injected into a series of growth reactors connected in series, thus avoiding the use of large reactors, saving stirring power, and effectively controlling the growth of precursor particles to obtain a precursor with a narrow particle size distribution.

[0058] In the current growth process, either an intermittent reactor is used to obtain hydroxide or carbonate precursor particles with a narrow particle distribution, or a large continuous stirred tank is used for precipitation and then aging. Industrial-scale synthesis can often only achieve the purpose of increasing production by increasing the number of reactors and operating multiple lines in parallel. This production method is inefficient, has high equipment and operating costs, and is difficult to control product quality, which does not meet the needs of large-scale industrial production.

[0059] Compared to these amplification methods by simply increasing the number of reactors, the present invention proposes a new continuous production mode, which uses a smaller reactor (nucleation reactor) to continuously synthesize the precursor nuclei, and then continuously injects the precursor nuclei into a larger reactor (growth reactor) in series. The nuclei of these precursors grow and crystallize on the surface of the precursor particles in the growth reactor, which promotes the growth of the precursor particles. This operation method is continuous, highly automated, requires less equipment investment, has low operating costs, and has stable product quality. It meets the needs of large-scale chemical production and has great advantages, especially in the production process of large-scale precursors.

[0060] The present invention provides a process for continuously producing battery material precursors. In the present invention, the precipitation process of the precursor is decomposed, a smaller reactor (nucleation reactor) is used to prepare nanocrystalline nuclei, and a larger reactor (growth reactor) connected in series is used to grow precursor particles. Figure 1 As shown, RN1-RN8 are nucleation reactors, and R1-R8 are growth reactors connected in series.

[0061] The number of growth reactor units used for the growth of precursor particles is greater than 6 (arranged in series), and each growth reactor unit is a fully mixed flow continuous reactor, and its inlet materials have at least two streams, at least one of which comes from the outlet of the previous fully mixed flow continuous growth reactor (providing precursor particles), and at least one of which comes from the nucleation reactor (providing crystal nuclei). In the growth reactor, the crystal nuclei grow on the surface of the precursor particles, making the precursor particles grow, such as Figure 1 shown. Figure 1 8 growth kettles are shown in the figure, and the particle size of the precursor particles in the kettles gradually increases. By increasing the number of growth kettles, the difference in the particle size of the precursor particles in adjacent growth kettles (the n+1th kettle and the nth kettle) can be reduced, so that an extremely narrow precursor particle size distribution can be obtained.

[0062] The number of nucleation reactors can be one or more. The nuclei continuously prepared by the nucleation reactors can be allocated according to the needs of a series of growth reactors, for example, Figure 2 As shown, in one embodiment, the growth reactors R2-R4 are connected in parallel to form the nucleation reactor RN2, and the growth reactors R5-R8 are connected in parallel to form the nucleation reactor RN3.

[0063] Figure 2 The N independent series-connected growth reactors shown in the figure can also be replaced by a tubular reactor. N separated chambers are arranged in the tubular reactor. Each chamber has a stirring paddle (vertical stirring paddle). The material flows from left to right, that is, from the Nth chamber to the N+1th chamber. Each chamber needs to continuously add crystal nuclei, such as Figure 3 shown. Figure 3 The principle and Figure 2 The same, that is Figure 2 The N independent growth reactors are equivalent to Figure 3 There are N cavities in it. Figure 3 The E-25 in the figure indicates the motor driving the stirring device.

[0064] In a preferred embodiment, in a continuous production process, one or more filtering units may be provided to filter the liquid-solid mixture in the growth reactor to remove the solvent (water) to increase the concentration of the precursor particles, and then the concentrated precursor suspension is added to the next stage growth reactor, such as Figure 4 As shown. This can significantly improve the production efficiency of the growth reactor. Figure 4 There is one filtration unit (F1) and 18 continuous stirred tanks.

[0065] The nucleation reactor can be fed with liquid or solid-liquid materials simultaneously.

[0066] During the preparation of the precursor, some solid feed (S1) can be added from a storage tank or container (V1) after the filtration unit, such as Figure 4 As shown (in the figure, P1 represents a delivery pump).

[0067] Figure 4 The system shown can be stacked by using two horizontal tubular continuous stirred reactors, and part of the reaction chamber shares a nucleation reactor, such as Figure 5 shown.

[0068] The above is the overall concept of the present invention, and detailed embodiments and comparative examples are provided below on the basis of the overall concept of the present invention to further illustrate the present invention.

[0069] The following examples are Figure 1 The system shown carries out continuous production of battery material precursors, and the system includes 8 growth kettles (R1-R8) connected in series, each of which is independently connected to a nucleation kettle (RN1-RN8), and each nucleation kettle and each growth kettle are provided with a stirring device.

[0070] Example 1

[0071] To prepare Ni 0.8 Co 0.1 Mn 0.1Taking the nickel-cobalt-manganese precursor of (OH)2 as an example, Figure 1 The system shown in the figure was prepared with the following specific reaction conditions:

[0072] The reaction conditions of the nucleation reactor are as follows: pH 11-12, reaction temperature 20-80°C (the target temperature controlled in this example is 45°C);

[0073] The reaction conditions of the growth reactor are: pH 11-12, reaction temperature 20-80°C (the target temperature controlled in this example is 45°C).

[0074] The raw materials used to prepare the battery material precursor include a mixed salt prepared according to the battery material precursor and an alkali used as a precipitant. Specifically, the mixed salt is a corresponding mixed sulfate, and the molar concentration of the mixed salt is 2 mol / L (the sum of the molar concentrations of all sulfates); the alkali is ammonia water, and the concentration is 4 mol / L. The ratio of the amount of ammonia water and the amount of sulfate added is 1:6.

[0075] The flow rate of the mixed salt added to the nucleation reactor RN-1 was 2 L / min, the flow rate of the alkali was 4.10 L / min, and the volume of the nucleation reactor was 5 liters;

[0076] The flow rate of the mixed salt added to the nucleation reactors RN-2 to RN-8 is 2 L / min, the flow rate of the alkali is 4.04 L / min, and the volume of the nucleation reactor is 5 liters.

[0077] The volume of the growing kettles R1-R8 is 100 liters.

[0078] After continuous reaction, a sample is taken at the outlet of R8, and the obtained solid is filtered, washed, and dried to obtain a precursor product, whose morphology is as follows: Figure 6 shown.

[0079] Example 2

[0080] To prepare Ni 0.8 Co 0.1 Al 0.1 (OH) 2.1 Taking the nickel-cobalt-aluminum precursor as an example, Figure 1 For the preparation of the system shown, suitable reaction conditions are as follows:

[0081] The reaction conditions of the nucleation reactor are as follows: pH 11-12, reaction temperature 20-80°C (the target temperature controlled in this example is 70°C);

[0082] The reaction conditions of the growth reactor are: pH 11-12, reaction temperature 20-80°C (the target temperature controlled in this example is 60°C).

[0083] The raw materials used to prepare the battery material precursor include a mixed salt prepared according to the battery material precursor and an alkali used as a precipitant. Specifically, the mixed salt is a corresponding mixed sulfate, and the molar concentration of the mixed salt is 2 mol / L; the alkali is ammonia water, and the concentration is 4 mol / L. The ratio of the amount of ammonia water and the amount of sulfate added is 1:6.

[0084] The flow rate of the mixed salt added to the nucleation reactor RN-1 was 2 L / min, the flow rate of the alkali was 4.10 L / min, and the volume of the nucleation reactor was 5 liters;

[0085] The flow rate of the mixed salt added to the nucleation reactors RN-2 to RN-8 is 2 L / min, the flow rate of the alkali is 4.04 L / min, and the volume of the nucleation reactor is 5 liters.

[0086] The volume of the growing kettles R1-R8 is 500 liters.

[0087] After continuous reaction, a sample is taken at the outlet of R8, and the obtained solid is filtered, washed, and dried to obtain a precursor product, whose morphology is as follows: Figure 7 shown.

[0088] Example 3

[0089] To prepare Ni 0.8 Co 0.1 Mn 0.1 Taking the nickel-cobalt-manganese precursor of (OH)2 as an example, Figure 1 The system shown in the figure was prepared with the following specific reaction conditions:

[0090] The reaction conditions of the nucleation reactor are as follows: pH 11-12, reaction temperature 20-80°C (the target temperature controlled in this example is 30°C);

[0091] The reaction conditions of the growth reactor are: pH 11-12, reaction temperature 20-80°C (the target temperature controlled in this example is 40°C).

[0092] The raw materials used to prepare the battery material precursor include a mixed salt prepared according to the battery material precursor and an alkali used as a precipitant. Specifically, the mixed salt is a corresponding mixed sulfate, and the molar concentration of the mixed salt is 2 mol / L; the alkali is ammonia water, and the concentration is 4 mol / L. The ratio of the amount of ammonia water and the amount of sulfate added is 1:6.

[0093] The flow rate of the mixed salt added to the nucleation reactor RN-1 was 2 L / min, the flow rate of the alkali was 4.10 L / min, and the volume of the nucleation reactor was 5 liters;

[0094] The flow rate of the mixed salt added to the nucleation reactors RN-2 to RN-8 is 2 L / min, the flow rate of the alkali is 4.04 L / min, and the volume of the nucleation reactor is 5 liters.

[0095] The volume of the growing kettles R1-R8 is 250 liters.

[0096] After continuous reaction, samples were taken from the growth reactors R1-R8, and their particle size parameters (D10, D50, D90) were measured. The corresponding particle distribution change results are shown in Table 1 (particle size unit is μm). The smaller the P value, the narrower the particle size distribution.

[0097] Table 1 Here

[0098]

[0099] It can be seen from the test results that, by adopting the method of the present invention, the particle size gradually increases, the particle size difference gradually decreases, and the distribution becomes narrower, which is a favorable result.

[0100] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to specific details.

Claims

1. A continuous production system for a battery positive electrode material precursor capable of controlling particle size distribution, characterized in that: It comprises N reaction chambers connected in series, each reaction chamber is connected to a nucleation kettle, and each reaction chamber and each reaction kettle is provided with a stirring device; Wherein, N is an integer greater than 6.

2. The continuous production system of battery positive electrode material precursor with controllable particle size distribution according to claim 1, characterized in that: The ratio of the volume of the reaction chamber to the volume of the nucleation reactor is 5 to 1000.

3. The continuous production system of battery positive electrode material precursor with controllable particle size distribution according to claim 2, characterized in that: Except for the first reaction chamber, the feed of each of the other reaction chambers includes at least two streams: at least one stream comes from the discharge of the previous reaction chamber, and at least one stream comes from the discharge of the correspondingly connected nucleation reactor.

4. The continuous production system of battery positive electrode material precursor with controllable particle size distribution according to claim 3, characterized in that: Each reaction chamber is independently connected to a nucleation kettle, or a plurality of adjacent reaction chambers are connected in parallel to a nucleation kettle.

5. The continuous production system of battery material precursors with controllable particle distribution according to claim 4, characterized in that: N reaction chambers are formed by N growth kettles connected in series, and each reaction kettle is provided with a stirring device.

6. The continuous production system of battery material precursors with controllable particle distribution according to claim 4, characterized in that: N reaction chambers are placed in a tubular reactor, that is, the tubular reactor is partitioned by partitions to form N reaction chambers separated in sequence and arranged in sequence along the axial direction of the reactor, and the material can flow in sequence along the N series-connected reaction chambers, and N stirring devices are placed in the N reaction chambers and share a stirring shaft.

7. A continuous production process of a battery positive electrode material precursor capable of controlling particle size distribution, characterized in that: The system according to any one of claims 1 to 6 is used to produce battery material precursors, and the process is: Raw materials for preparing battery positive electrode material precursors are added into each nucleation reactor, and a suspension of precursor crystal nuclei is formed by heating and stirring; Each nucleation reactor transports the suspension of the precursor crystal nuclei to the corresponding connected reactor for reaction under heating and stirring, and the output from each reactor is transported to the adjacent next-stage reactor.

8. The continuous production process of battery material precursor with controllable particle distribution according to claim 7, characterized in that: The reaction conditions in the nucleation reactor are: pH 11-12, reaction temperature 20-80°C; The reaction conditions in the reactor are: pH 11-12, and reaction temperature 20-80°C.

9. The continuous production process of battery material precursor with controllable particle distribution according to claim 8, characterized in that: in, Each reactor is independently connected to a nucleation reactor.

10. The continuous production process of battery material precursor with controllable particle distribution according to claim 9, characterized in that: The raw materials used to prepare the battery material precursor include a mixed salt prepared according to the proportion of the battery positive electrode material precursor and an alkali used as a precipitant, and the mixed salt includes a salt containing nickel, cobalt and manganese; The molar concentration of the mixed salt in the raw materials added to the nucleation reactor is 1.0-4.0 mol / L; the molar concentration of the alkali is 2.0-8.0 mol / L, and the molar ratio of the alkali to the mixed salt is (0.5-3.0):1.

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