Positive electrode active material precursor preparation device and preparation method

Abstract

The apparatus for preparing a positive electrode active material precursor according to an embodiment of the present invention may comprise: a reactor (100) in which reactants are accommodated and reacted; a supply unit (200) for supplying a reactant to the inside of the reactor (100); and a solution discharge unit (300) for continuously discharging, to the outside of the reactor (100), the solution among a precursor and a solution generated by the reaction of the reactant inside the reactor (100). Furthermore, the solution discharge part (300) comprises: a solution discharge pipe (310) communicating with the side wall (110) of the reactor (100) and extending to the outside; a metal filter unit (320) located in the solution discharge pipe (310) for separating the positive electrode active material precursor from the solution; the nitrogen purging unit (330) is used for purging nitrogen to the metal filter unit (320); the blocking unit (340) is positioned behind the nitrogen purging unit (330); and a decompression pump (350) located at the rear end of the blocking unit (340), the metal filter unit (320) may be located at one end of the solution discharge pipe (310) adjacent to the reactor (100).

Description

Technical Field

[0001] This embodiment relates to a device and method for preparing a cathode active material precursor, and more particularly to a device and method for preparing a cathode active material precursor by continuous concentration in a reactor. Background Art

[0002] Recently, with the explosive growth in demand for electric vehicles and the requirement for increased driving mileage, secondary batteries with high capacity and high energy density that meet the requirements are being actively developed worldwide.

[0003] As a positive electrode active material of a lithium secondary battery, a lithium composite transition metal oxide including a transition metal such as nickel, cobalt, manganese, aluminum, etc. is widely used.

[0004] The lithium composite transition metal oxide is prepared by the following method: a cathode active material precursor in the form of a transition metal hydroxide or oxyhydroxide is mixed with a lithium raw material and then fired. Specifically, the cathode active material can be prepared by the following method: a cathode active material precursor is prepared by a continuous reactor (CSTR) and then fired together with a lithium raw material; or a cathode active material precursor is prepared by a batch reactor and then fired together with a lithium raw material. The continuous reactor (CSTR) adopts a method of adding raw materials for co-precipitation and discharging the precursor formed into particles at the same time, while the batch reactor adopts a method of adding a predetermined amount of raw materials to the reactor within a certain period of time for reaction and discharging the precursor after the reaction is completed.

[0005] The batch method is a method in which the reactor is cleaned after the reaction is completed to readjust the initial conditions and repeat the positive electrode active material preparation reaction, which has the problem of low productivity.

[0006] For cathode active material precursors prepared using a continuous reactor (CSTR), the productivity of the cathode active material precursor can be improved by discharging the precursor while adding raw materials for co-precipitation. The continuous reactor (CSTR) has a structure in which raw materials are added and products are discharged continuously at the same time. Due to the complex system structure, there are problems such as increased system preparation costs and low system space utilization efficiency. In addition, the residence time and reaction time of the cathode active material precursor generated in the reactor may deviate, resulting in a problem of decreased size and particle size uniformity of the generated cathode active material precursor particles.

[0007] Therefore, it is necessary to develop a preparation device and preparation method that can improve production efficiency and improve the space utilization efficiency of equipment, so as to prepare high-quality positive electrode active material precursors. Summary of the Invention

[0008] Technical problems to be solved

[0009] In one embodiment of the present invention, an apparatus and method for preparing a cathode active material precursor by continuous concentration in one reactor are provided.

[0010] Technical Solution

[0011] According to one embodiment of the present invention, a positive electrode active material precursor preparation apparatus may include: a reactor 100 for containing reactants for reaction; a supply unit 200 for supplying reactants into the reactor 100; and a solution discharge unit 300 for continuously discharging the precursor and solution generated by the reaction of the reactants within the reactor 100 to the outside of the reactor 100. The solution discharge unit 300 may include: a solution discharge pipe 310 connected to the sidewall 110 of the reactor 100 and extending to the outside; a metal filter unit 320 located in the solution discharge pipe 310 for separating the positive electrode active material precursor from the solution; a nitrogen purge unit 330 for purging nitrogen into the metal filter unit 320; a blocking unit 340 located at the rear end of the nitrogen purge unit 330; and a pressure reduction pump 350 located at the rear end of the blocking unit 340. Furthermore, the metal filter unit 320 may be located at one end of the solution discharge pipe 310 adjacent to the reactor 100.

[0012] The nitrogen purge unit 330 may include a first nitrogen purge unit 331 and a second nitrogen purge unit 332 , which are respectively located on both sides of the metal filter unit 320 in the solution flow direction of the solution discharge pipe 310 .

[0013] The first nitrogen purge unit 331 may continuously spray nitrogen toward a side of the metal filter unit 320 facing the reactor 100 . The nitrogen spraying rate of the first nitrogen purge unit 331 may be in a range of 50 LPM to 100 LPM.

[0014] When the reactants contained in the reactor 100 exceed the maximum liquid level A1 of the reactor 100, the second nitrogen purge unit 332 can spray nitrogen to the other side of the side of the metal filter unit 320 facing the reactor 100 to desorb the precursor attached to the metal filter unit 320. The nitrogen injection rate of the second nitrogen purge unit 332 can be in the range of 250LPM to 500LPM.

[0015] Before the second nitrogen purge unit 332 sprays nitrogen, the blocking unit 340 may be turned off.

[0016] The maximum liquid level A1 of the reactor 100 may be located above the portion where the sidewall 110 of the reactor 100 is connected to the solution discharge pipe 310, and may be located below the upper 1 / 10 of the reactor 100. There are no particular limitations as long as the rising of the reactants does not affect the reaction in the reactor 100.

[0017] The solution discharge pipe 310 may be connected to the solution discharge pipe 310 at a position at or above the upper 2 / 5 of the entire height of the side wall 110 of the reactor 100 .

[0018] The metal filter unit 320 is fixed to the solution discharge pipe 310 via a detachable fixing component and is replaceable.

[0019] The metal filter unit 320 may be formed by stacking metal filters with pore sizes ranging from 0.2 μm to 0.8 μm.

[0020] A control unit 500 may be included to control the operations of the supply unit 200 , the nitrogen purge unit 300 , the blocking unit 340 , and the decompression pump 350 .

[0021] When the control unit 500 stops the operation of the decompression pump 350 , the blocking unit 340 may be turned off.

[0022] According to another embodiment of the present invention, a method for preparing a positive electrode active material precursor may include: continuously adding raw materials to a reactor for stirring and reacting to form reactants; discharging the separated solution in the reactor to the outside of the reactor through a metal filter unit located in a solution discharge pipe connected to the side wall of the reactor; and a nitrogen purge step of spraying nitrogen into the metal filter unit when the reactants in the reactor reach the maximum liquid level in the reactor. In the nitrogen purge step, nitrogen can be sprayed into the solution discharge pipe, and the sprayed nitrogen flows from the inside of the solution discharge pipe toward the inside of the reactor.

[0023] For the nitrogen purging step, after closing the blocking unit located at the rear end of the solution discharge pipe, the solution may be sprayed at a spray speed ranging from 250 LPM to 500 LPM.

[0024] In the nitrogen purging step, before closing the blocking unit, the operation of the pressure reducing pump located at the rear end of the blocking unit may be stopped first.

[0025] In the solution discharge step, when the reactants in the reactor reach above the lowermost end point of the connection portion between the reactor and the solution discharge pipe connected to the side wall of the reactor, the pressure reducing pump located in the solution discharge pipe can be started to discharge the solution.

[0026] In the solution discharging step, nitrogen gas may be continuously sprayed to a side of the metal filter unit facing the reactor, and the nitrogen gas may be sprayed at a range of 50 LPM to 100 LPM.

[0027] Beneficial effects

[0028] According to one embodiment of the present invention, since the positive electrode active material precursor can be prepared by continuous concentration in one reactor, it has the advantages of simplifying the device configuration and reducing the investment cost.

[0029] In addition, since the device configuration is simplified, there is an advantage of improving space utilization efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of the structure of a device for preparing a positive electrode active material precursor according to an embodiment of the present invention.

[0031] Figure 2 FIG. 4 is a schematic diagram of a metal filter unit located inside a solution discharge pipe according to an embodiment of the present invention.

[0032] Figure 3 The figure is a schematic diagram of a process of injecting nitrogen gas during operation of a nitrogen purge unit according to an embodiment of the present invention.

[0033] Figure 4 It is a structural schematic diagram of a positive electrode active material precursor preparation device including a control unit. DETAILED DESCRIPTION

[0034] In the description of the present invention, terms such as first, second, and third are used to describe various parts, components, regions, layers, and / or segments, but these parts, components, regions, layers, and / or segments should not be limited by these terms. These terms are only used to distinguish one part, component, region, layer, and / or segment from another part, component, region, layer, and / or segment. Therefore, without departing from the scope of the present invention, the first part, component, region, layer, and / or segment described below can also be described as the second part, component, region, layer, and / or segment.

[0035] The terms used herein are for the purpose of describing specific embodiments only and are not intended to limit the present invention. Unless the context clearly indicates otherwise, the singular forms used herein are intended to include the plural forms. As used in the specification, "comprising" may specifically refer to a certain characteristic, field, integer, step, action, element and / or component, but does not exclude the existence or addition of other characteristics, fields, integers, steps, actions, elements, components and / or groups.

[0036] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Dictionary-defined terms should be interpreted as having the same meaning as that in the relevant technical literature and disclosed herein, and should not be interpreted in an idealized or overly formal sense.

[0037] In the accompanying drawings, for the sake of convenience and clarity of description, the size of each component or a specific part constituting the component is exaggerated, omitted, or schematically shown. Therefore, the size of each component does not fully reflect the actual size. When it is considered that a detailed description of the relevant known function or structure may unnecessarily obscure the gist of the present invention, the detailed description will be omitted.

[0038] Modes for Carrying Out the Invention

[0039] Hereinafter, embodiments of the present invention will be described in detail. However, the following embodiments are merely examples, and the present invention is not limited to the following embodiments, but is defined only by the scope of the claims.

[0040] Figure 1 1 is a schematic structural diagram of a device for preparing a positive electrode active material precursor according to one embodiment of the present invention. Figure 2 FIG. 4 is a schematic diagram of a metal filter unit located inside a solution discharge pipe according to an embodiment of the present invention.

[0041] In the following, reference will be made to Figure 1 and Figure 2 A device for preparing a positive electrode active material precursor according to one embodiment of the present invention is described in detail.

[0042] According to one embodiment of the present invention, a positive electrode active material precursor preparation device may include: a reactor 100, for accommodating reactants inside for reaction; a supply part 200, for supplying reactants into the interior of the reactor 100; and a solution discharge part 300, for continuously discharging the precursor and the solution generated by the reaction of the reactants inside the reactor 100 to the outside of the reactor 100.

[0043] Reactor 100 may be formed with a space inside that can accommodate reactants, agitation components, and other necessary components. Specifically, it may include: a bottom (not shown); sidewalls 110 extending upward from the edge of the bottom and forming a receiving portion together with the bottom; and an upper cover 120 positioned facing the bottom (not shown) to prevent the reactants inside reactor 100 from being discharged to the outside. The bottom and sidewalls 110 may be connected by welding, and upper cover 120 may cover the upper end of sidewall 110 using additional fixing components.

[0044] The stirring portion 130 for mixing the reactants added to the inside can be located at the center of the reactor 100. The stirring portion 130 may include a stirring shaft 131 and a stirring blade 132. The stirring portion 130 can rotate under the drive of a driving portion (not shown) to stir the reactants contained in the reactor 100. The driving portion (not shown) is electrically connected to the control portion 500 described below, and can start driving or stop driving by the control portion 500, and the rotation speed can be adjusted. The stirring blade 132 can be equipped with more than one, and according to the size and needs of the reactor, a plurality of can be arranged at different heights, which is obvious.

[0045] Alternatively, a liquid level gauge (not shown) may be located within the reactor 100, capable of measuring a minimum liquid level A0 and a maximum liquid level A1 from the bottom upward, based on vertical height. The minimum liquid level A0 is based on the minimum amount of reactants added to initiate the positive electrode active material precursor preparation reaction, while the maximum liquid level A1 is based on whether the second nitrogen purge unit 332 described below is activated. This will be further described in the description of the solution discharge unit 300 below.

[0046] In addition, the reactor 100 may be equipped with a pH sensor 400 to adjust the reaction conditions.

[0047] The supply unit 200 can be located around the stirring unit 130. The first raw material supply unit 210 and the second raw material supply unit 220 are distinguished in the figure, but this is a distinction made for ease of description. The added substances can be supplied by one supply unit or additional supply units can be further positioned to supply various substances respectively. On the other hand, a nitrogen supply unit 230 can also be included to remove the dissolved oxygen in the reactants added to the reactor 100. Each supply unit 200 can adjust the supply start, stop and supply speed of each reactant by the following control unit 500. In addition, for the position of each supply unit, the relative position can be adjusted as needed for arrangement.

[0048] The solution discharge portion 300 may include: a solution discharge pipe 310, which is connected to the side wall 110 of the reactor 100 and extends to the outside; a metal filter unit 320, which is located in the solution discharge pipe 310 and is used to separate the positive electrode active material precursor and the solution; a nitrogen purge unit 330, which is used to purge nitrogen into the metal filter unit 320; a blocking unit 340, which is located behind the nitrogen purge unit 330; and a pressure reducing pump 350, which is located at the rear end of the blocking unit 340.

[0049] Furthermore, in the description of the present invention, “front end / front” or “rear end / rear” may be distinguished based on the flow direction of the solution discharged from the reactor to the outside.

[0050] The solution discharge pipe 310 may be in the form of a pipe and is not particularly limited as long as it can smoothly discharge the solution to the outside of the reactor 100 .

[0051] The solution discharge pipe 310 may be a structure that penetrates the sidewall 110 of the reactor 100 to connect the inner space of the reactor 100 with the inner space of the solution discharge pipe 310 .

[0052] The solution discharge pipe 310 may include a metal filter unit 320 located within the entire cross-section of the solution discharge pipe 310 that is connected to the sidewall 110 of the reactor 100. The metal filter unit 320 may be composed of a plurality of stacked metal filters. The pore size of the metal filter may be in the range of 0.1 μm to 1.0 μm, specifically in the range of 0.2 μm to 0.8 μm, and more specifically in the range of 0.4 μm to 0.6 μm. When the pore size of the metal filter is within the above range, it is beneficial to smoothly discharge the solution to the outside of the reactor and prevent the prepared positive electrode active material precursor from being lost to the outside.

[0053] The metal filter unit 320 can be fixed to the solution discharge pipe 310 by a detachable fixing component. In addition, if the metal filter unit 320 needs to be replaced, it can be replaced with a new metal filter unit 320 by removing the fixing component. The fixing component can be configured to include fixing holes located in the metal filter unit 320 and the solution discharge pipe 310, respectively, and a component embedded in the fixing hole, or it can be a locking fixing component. The fixing component fixes the metal filter unit 320 to the solution discharge pipe 310, and is not particularly limited as long as it can only allow the solution in the reactor 100 to be discharged to the outside through the solution discharge pipe 310, while the positive electrode active material precursor remains inside the reactor 100.

[0054] On the other hand, the metal filter unit 320 can be detachably fixed to the side wall 110 of the reactor 100. Specifically, the metal filter unit 320 can cover and be located on the entire connection portion between the reactor 100 and the solution discharge pipe 310. This facilitates separation of the solution in the reactor 100 and discharge to the outside through the solution discharge pipe 310.

[0055] Furthermore, although not shown in the figures, a liquid level gauge may also be located at the lowest point of the portion where the solution discharge pipe 310 connects to the sidewall 110 of the reactor 100. The liquid level gauge is electrically connected to the control unit 500 described below. Thus, when the level of the reactants loaded into the reactor 100 reaches the lowest point, the control unit 500 can control the pressure reducing pump 350 to start.

[0056] The nitrogen purge unit 330 can prevent the positive electrode active material precursor from adhering to the metal filter unit 320 or can play a role in desorbing the positive electrode active material precursor adhering to the metal filter unit 320. Specifically, the nitrogen purge unit 330 may include a first nitrogen purge unit 331 and a second nitrogen purge unit 332, which are respectively located on both sides of the metal filter unit 320 in the solution flow direction of the solution discharge pipe 310.

[0057] Reference Figure 3 (a) is a schematic diagram of the process of starting the first nitrogen purge unit 332 to spray nitrogen. The first nitrogen purge unit 331 can continuously spray nitrogen onto the side of the metal filter unit 320 facing the reactor 100 to disperse the positive electrode active material precursor and enter the solution discharge pipe 310 together with the solution, or to prevent the positive electrode active material precursor from adhering to the metal filter unit 320. The nitrogen injection rate of the first nitrogen purge unit 331 can be in the range of 50 LPM to 100 LPM. When the nitrogen injection rate is within the range, it has the following advantages: without affecting the reaction of the reactants in the reactor 100, the positive electrode active material precursor can be effectively dispersed, thereby preventing or hindering the positive electrode active material precursor from adhering to the metal filter unit 320.

[0058] At this time, the blocking unit 340 described below is kept in an open state, and the decompression pump 350 described below may be in an operating state.

[0059] Figure 1 1 and 2. The first nitrogen purge unit 331 is shown as penetrating the upper cover 120 of the reactor 100 and located above the portion where the sidewall 110 of the reactor 100 is connected to the solution discharge pipe 310. However, it can be positioned in front of the metal filter unit 320 through the solution discharge pipe 310 as needed. In addition, nitrogen can be directly injected into the metal filter unit 320. Nitrogen can be injected through the first nitrogen purge unit 331 to prevent or hinder the positive electrode active material precursor in the reactor 100 from adhering to the metal filter unit 320.

[0060] also, Figure 1 FIG. 3 shows that the first nitrogen purge unit 331 is vertically positioned, but may be tilted at a predetermined angle.

[0061] In addition, the nitrogen gas outlet at the end of the first nitrogen purge unit 331 may have multiple branch pipes, specifically, branch pipes positioned opposite to each other. This facilitates dispersing the positive electrode active material precursor contained in the solution entering the solution discharge pipe 310, thereby preventing the positive electrode active material precursor from adhering to the metal filter unit 320.

[0062] The second nitrogen purge unit 332 may be positioned through the solution discharge pipe 310 , specifically, may be located between the metal filter unit 320 and the blocking unit 340 described below, and may spray nitrogen into the solution discharge pipe 310 .

[0063] The second nitrogen purge unit 332 can spray nitrogen to the other side of the side of the metal filter unit 320 facing the reactor 100. Specifically, when the reactants contained in the reactor 100 exceed the highest liquid level A1 of the reactor 100, nitrogen can be sprayed to the other side of the side of the metal filter unit 320 facing the reactor 100, thereby desorbing the precursor attached to the metal filter unit 320. When the solution in the reactor 100 is discharged to the outside through the solution discharge pipe 310, the positive electrode active material precursor prepared in the reactor 100 may adhere to the metal filter unit 320. As the amount of the positive electrode active material precursor attached increases, the solution discharge speed slows down, and the reactants in the reactor 100 increase. When the reactants in the reactor 100 increase and reach the highest liquid level A1 of the reactor, the blocking unit 340 described below can be closed and the second nitrogen purge unit 332 can be started to spray nitrogen.

[0064] Reference Figure 3 (b) shows a schematic diagram of the process of starting the second nitrogen purge unit 332 to spray nitrogen. When the reactants in the reactor 100 increase to the reactor's maximum liquid level A1, the operation of the pressure reducing pump 350 described below can be stopped, the blocking unit 340 can be turned off, and then the second nitrogen purge unit 332 can be started to spray nitrogen. The nitrogen sprayed from the second nitrogen purge unit 332 moves into the interior of the reactor 100, thereby detaching the positive electrode active material precursor attached to the metal filter unit 320.

[0065] At this time, the nitrogen injection rate of the second nitrogen purge unit 332 can be in the range of 100 LPM to 1000 LPM, specifically in the range of 250 LPM to 500 LPM, and the injection time can be in the range of 0.1 second to 1 second. When the nitrogen injection rate and injection time are within the above ranges, the positive electrode active material precursor attached to the metal filter unit 320 can be effectively detached while minimizing the impact on the positive electrode active material precursor preparation process.

[0066] The reactor 100 and the solution discharge pipe 310 can be connected and communicated at a position on the sidewall 110 of the reactor 100 that is lower than the highest liquid level A1 of the reactor 100. Alternatively, the reactor 100 and the solution discharge pipe 310 can be connected and communicated at a position that is at least at the upper 2 / 5 of the total height of the sidewall 110 of the reactor 100. This helps improve the productivity of the entire preparation apparatus.

[0067] On the other hand, the solution discharge pipe 310 can be positioned downwardly tilted from the reactor 100 toward the outside of the reactor 100 on a horizontal basis. This facilitates the solution inside the reactor 100 to be discharged to the outside of the reactor 100 through the solution discharge pipe 310 after passing through the metal filter unit 320.

[0068] In addition, the solution discharge pipe 310 may be positioned horizontally, or may be positioned according to space and other needs.

[0069] The decompression pump 350 may be located in the solution discharge pipe 310, specifically, behind the blocking unit 340. The driving of the decompression pump 350 facilitates separation of the solution in the reactor 100 and discharge to the outside.

[0070] The solution that passes through the metal filter unit 320 and is discharged to the outside through the solution discharge pipe 310 may be stored in a separate storage tank or may directly flow into a wastewater treatment plant.

[0071] Figure 4 It is a structural schematic diagram of a positive electrode active material precursor preparation device including a control unit.

[0072] Reference Figure 4 The positive electrode active material precursor preparation apparatus according to one embodiment of the present invention may include a control unit 500. The control unit 500 may be electrically connected to the supply unit 200, the nitrogen purge unit 300, the blocking unit 340, the pressure reducing pump 350, and the liquid level meter (not shown).

[0073] When the reactants in the reactor 100 reach the maximum liquid level A1, the control unit 500 can stop the operation of the pressure reducing pump 350 and / or turn off the blocking unit 340 through the electrical connection of the liquid level gauge (not shown) located at the maximum liquid level A1, and then start the second nitrogen purge unit 332 to inject nitrogen. At this time, the injection rate and injection time of the nitrogen have been described above and are omitted here.

[0074] In another embodiment of the present invention, a method for preparing a positive electrode active material precursor may be provided. Specifically, a method for preparing a positive electrode active material precursor using the aforementioned positive electrode active material precursor preparation apparatus may be provided.

[0075] The method for preparing a positive electrode active material precursor according to the present invention may include: a step of continuously adding raw materials into a reactor for stirring and reacting to form reactants; a solution discharge step of discharging the solution in the reactor separated by a metal filter unit located in a solution discharge pipe connected to the side wall of the reactor to the outside of the reactor; and a nitrogen purge step of spraying nitrogen into the metal filter unit when the reactants in the reactor reach the highest liquid level of the reactor. For the nitrogen purge step, nitrogen can be sprayed into the solution discharge pipe, and the sprayed nitrogen flows from the inside of the solution discharge pipe toward the inside of the reactor.

[0076] First, the method for preparing a positive electrode active material precursor may include the steps of continuously adding raw materials into a reactor for stirring and reacting to form reactants.

[0077] The raw materials for preparing the positive electrode active material precursor according to the present invention can mainly include metal element-containing raw materials, ammonia-containing raw materials and caustic soda, and can include additional raw materials as needed. In the drawings of the present invention, the supply unit for preparing the raw materials is only divided into a first raw material supply unit and a second raw material supply unit, and there is no specific distinction. The raw materials for preparing can be supplied separately by any supply unit, or can be supplied simultaneously by one supply unit. In addition, although not shown in the figure, it is obvious that an additional supply unit can be further provided as needed to supply the raw materials for preparation separately.

[0078] The metal element-containing raw material can be one or more selected from metal oxides, metal salts, or metal hydroxides, and is not particularly limited as long as it can be used as a positive electrode active material precursor for lithium secondary batteries. The metal element-containing raw material can be supplied at a rate of 300 to 2500 kg / h, maintaining a constant rate or varying the supply rate in each section, without particular limitation, as long as the positive electrode active material precursor required by the present invention can be effectively prepared.

[0079] The supply rate of the ammonia-containing raw material can be 10 to 200 kg / h. The ammonia-containing raw material can be an NH4OH solution, which is not particularly limited as long as it can effectively prepare the positive electrode active material precursor required by the present invention.

[0080] On the other hand, the supply rate of the caustic soda (NaOH) solution may be 100 to 2000 kg / h.

[0081] The ammonia-containing raw material and caustic soda may be supplied at a certain rate within the supply rate range, or the supply rates in each section may be changed, without particular limitation as long as the positive electrode active material precursor required by the present invention can be effectively prepared.

[0082] In the present invention, the raw material solution is preferably added to the reactor to reach above the reactor's minimum liquid level A0 to prepare the positive electrode active material precursor. When the reactor's minimum liquid level A0 is reached or above, it is beneficial to prepare a positive electrode active material precursor with uniform quality.

[0083] Alternatively, the raw material solution may be added to the reactor while the stirring unit is activated to stir the added raw material solution. The stirring speed may be in the range of 10 to 2000 rpm, specifically 50 to 300 rpm. The stirring speed is not particularly limited as long as the positive electrode active material precursor required by the present invention can be prepared by smooth stirring.

[0084] At this time, nitrogen gas may be purged at a rate of 80 to 150 LPM through the nitrogen gas supply part 230 to remove dissolved oxygen in the raw material solution.

[0085] When the raw material solution starts to be added to the reactor 100 , the blocking unit 340 located in the solution discharge pipe 310 connected to the reactor 100 may be kept in an open state.

[0086] On the other hand, when the height of the reactants inside the reactor 100 rises to above the lowest end point of the portion where the side wall 110 of the reactor 100 is connected to the solution discharge pipe 310, nitrogen can be purged at a spray rate in the range of 50 LPM to 100 LPM toward the front side of the metal filter unit 320 (based on the direction in which the solution flows from the reactor to the outside) through the first nitrogen purge unit. In addition, nitrogen can be purged directly from the upper side to the metal filter unit 320. In this way, the positive electrode active material precursor can be dispersed, thereby preventing or hindering adhesion to the metal filter unit 320, and only the solution in the reactor 100 is effectively discharged to the outside, which has the advantage of concentrating the positive electrode active material precursor and continuously preparing it.

[0087] Furthermore, when the level of the reactants in the reactor 100 rises above the lowest point where the sidewall 110 of the reactor 100 is connected to the solution discharge pipe 310, the pressure-reducing pump 350 can be activated. At this point, an electrical signal is transmitted to the control unit 500 via the liquid level gauge at the lowest point, thereby controlling the pressure-reducing pump 350 to be activated.

[0088] When the height of the reactants in the reactor 100 reaches the highest liquid level A1 of the reactor 100, the control unit 500 can stop the operation of the pressure reducing pump 350 through the electrical signal of the liquid level gauge (not shown in the figure), turn off the blocking unit 340, and then start the second nitrogen purge unit 332 to spray nitrogen. At this time, the nitrogen injection rate of the second nitrogen purge unit 332 can be in the range of 100 LPM to 1000 LPM, specifically in the range of 250 LPM to 500 LPM, and the injection time can be in the range of 0.1 seconds to 1 second. The nitrogen injected from the second nitrogen purge unit 332 moves to the interior of the reactor 100, which can detach the positive electrode active material precursor attached to the metal filter unit 320. The operation of injecting nitrogen from the second nitrogen purge unit 332 can be performed continuously more than once and is not particularly limited. Here, the height of the reactants in the reactor 100 reaches the highest liquid level A1 of the reactor 100. The reason is believed to be that the positive electrode active material precursor is attached to the metal filter unit 320, causing the solution to be unable to be discharged smoothly to the outside. Therefore, as described above, after the blocking unit 340 is closed, the second nitrogen purge unit 332 is activated to spray nitrogen. The sprayed nitrogen passes through the metal filter unit 320 and enters the interior of the reactor 100, thereby detaching the positive electrode active material precursor attached to the metal filter unit 320. The advantages of the nitrogen injection rate and injection time range are as described above and are omitted here.

[0089] After the nitrogen is ejected from the second nitrogen purge unit 332 , the blocking unit 340 may be opened and the pressure reducing pump 350 may be started.

[0090] In the present invention, when the mass of the solids is in the range of 5% to 65% relative to the total mass of the reactants in the reactor 100, the reaction is terminated, and a positive electrode active material precursor can be prepared by solid-liquid separation and subsequent treatment.

[0091] Although the positive electrode active material precursor preparation device according to the present invention has been described with reference to the accompanying drawings, the present invention is not limited to the embodiments and drawings described above and can be implemented in various different ways. Ordinary technicians in the technical field to which the present invention belongs can understand that it can be implemented in other specific ways without changing the technical ideas or necessary features of the present invention.

[0092] Description of Reference Numerals

[0093] 1: Positive electrode active material precursor preparation device

[0094] 100: Reactor

[0095] 110: Sidewall

[0096] 120: Upper cover

[0097] 130: Mixing section

[0098] 131: stirring shaft

[0099] 132: Mixing blade

[0100] 200: Supply Department

[0101] 210: First Raw Materials Supply Department

[0102] 220: Second Raw Material Supply Department

[0103] 230: Nitrogen Supply Department

[0104] 300: Solution discharge part

[0105] 310: Solution discharge pipe

[0106] 320: Metal filter unit

[0107] 330: Nitrogen purge unit

[0108] 331: First nitrogen purge unit

[0109] 332: Second nitrogen purge unit

[0110] 340: Blocking Unit

[0111] 350: Pressure reducing pump

[0112] 400: pH sensor unit

[0113] A0: minimum liquid level

[0114] A1: Maximum liquid level

Claims

1. A device for preparing a positive electrode active material precursor, comprising: A reactor (100) for containing reactants therein for reaction; a supply unit (200), configured to supply reactants into the reactor (100); as well as A solution discharge portion (300) is used to continuously discharge the precursor and the solution generated by the reaction of the reactants inside the reactor (100) to the outside of the reactor (100). The solution discharge part (300) comprises: a solution discharge pipe (310) communicating with the side wall (110) of the reactor (100) and extending to the outside; a metal filter unit (320), located in the solution discharge pipe (310), for separating the positive electrode active material precursor from the solution; a nitrogen purge unit (330), configured to purge nitrogen toward the metal filter unit (320); a blocking unit (340) located at the rear end of the nitrogen purge unit (330); and A pressure reducing pump (350) is located at the rear end of the blocking unit (340). The metal filter unit (320) is located at one end of the solution discharge pipe (310) adjacent to the reactor (100).

2. The positive electrode active material precursor preparation device according to claim 1, wherein: The nitrogen purge unit (330) comprises: A first nitrogen purge unit (331) and a second nitrogen purge unit (332) are respectively located on both sides of the metal filter unit (320) in the solution flow direction of the solution discharge pipe (310).

3. The positive electrode active material precursor preparation device according to claim 2, wherein: The first nitrogen purge unit (331) continuously sprays nitrogen onto a side of the metal filter unit (320) facing the reactor (100).

4. The positive electrode active material precursor preparation device according to claim 2, wherein: The nitrogen injection speed of the first nitrogen purge unit (331) is in the range of 50 LPM to 100 LPM.

5. The positive electrode active material precursor preparation device according to claim 2, wherein: When the reactants contained in the reactor (100) exceed the maximum liquid level (A1) of the reactor (100), The second nitrogen purge unit (332) sprays nitrogen to the other side of the metal filter unit (320) facing the reactor (100) to desorb the precursor attached to the metal filter unit (320).

6. The positive electrode active material precursor preparation device according to claim 5, wherein: The nitrogen injection speed of the second nitrogen purge unit (332) is in the range of 250 LPM to 500 LPM.

7. The positive electrode active material precursor preparation device according to claim 5, wherein: Before the second nitrogen purge unit (332) sprays nitrogen, First, the blocking unit (340) is closed.

8. The positive electrode active material precursor preparation device according to claim 5, wherein: The highest liquid level (A1) of the reactor (100) is located at a position higher than a portion where the side wall (110) of the reactor (100) is connected to the solution discharge pipe (310).

9. The positive electrode active material precursor preparation device according to claim 1, wherein: The solution discharge pipe (310) is connected to the solution discharge pipe (310) at a position above the upper 2 / 5 of the entire height of the side wall (110) of the reactor (100).

10. The positive electrode active material precursor preparation device according to claim 1, wherein: The metal filter unit (320) is fixed to the solution discharge pipe (310) via a detachable fixing component and is replaceable.

11. The positive electrode active material precursor preparation device according to claim 1, wherein: The metal filter unit (320) is formed by stacking metal filters with pore sizes ranging from 0.2 μm to 0.8 μm.

12. The positive electrode active material precursor preparation device according to claim 1, comprising: The control unit (500) is used to control the operation of the supply unit (200), the nitrogen purge unit (300), the blocking unit (340) and the pressure reducing pump (350).

13. The positive electrode active material precursor preparation device according to claim 12, wherein: When the control unit (500) stops the operation of the pressure reducing pump (350), the blocking unit (340) is closed.

14. A method for preparing a positive electrode active material precursor, comprising: The step of continuously adding raw materials into the reactor for stirring and reacting to form reactants; a solution discharge step of discharging the solution in the reactor separated by a metal filter unit located in a solution discharge pipe communicating with a side wall of the reactor to the outside of the reactor; and When the reactants in the reactor reach the highest liquid level in the reactor, nitrogen is sprayed into the nitrogen purge step of the metal filter unit. In the nitrogen purging step, nitrogen is sprayed into the solution discharge pipe, and the sprayed nitrogen flows from the inside of the solution discharge pipe toward the inside of the reactor.

15. The method for preparing a cathode active material precursor according to claim 14, wherein: For the nitrogen purge step, After closing the blocking unit at the rear end of the solution discharge pipe, The spraying is performed at a spraying rate ranging from 250 LPM to 500 LPM.

16. The method for preparing a cathode active material precursor according to claim 15, wherein: In the nitrogen purging step, Before closing the blocking unit, the operation of the pressure reducing pump located at the rear end of the blocking unit is stopped first.

17. The method for preparing a cathode active material precursor according to claim 14, wherein: In the solution discharging step, When the reactants in the reactor reach above the lowermost end point of the connection portion between the reactor and the solution discharge pipe connected to the reactor side wall, the pressure reducing pump located in the solution discharge pipe is started to discharge the solution.

18. The method for preparing a cathode active material precursor according to claim 14, wherein: In the solution discharging step, Nitrogen gas was continuously sprayed onto the side of the metal filter unit facing the reactor.

19. The method for preparing a cathode active material precursor according to claim 18, wherein: The nitrogen gas was injected in the range of 50 LPM to 100 LPM.

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