Apparatus and method for producing a positive electrode active material precursor for lithium secondary batteries

Abstract

The present invention relates to an apparatus and method for manufacturing a positive electrode active material precursor for a lithium secondary battery, and the apparatus for manufacturing a positive electrode active material precursor for a lithium secondary battery includes a reactor into which reaction raw materials are introduced and a reaction product is produced, an agitator that agitates the reaction raw materials, a solid-liquid separation member that is disposed between a side wall of the reactor and the agitator and performs solid-liquid separation in the reaction product, and a filtrate discharge port that is disposed above the solid-liquid separation member and separates and discharges a filtrate outside the reactor.

Description

[Technical Field]

[0001] The present embodiment relates to a lithium secondary battery, and more particularly to an apparatus and method for producing a positive electrode active material precursor for a lithium secondary battery. [Background technology]

[0002] As social concern grows over the depletion of fossil fuels and environmental pollution caused by their use, environmentally friendly energy sources are gaining attention as a solution to these problems. Among these environmentally friendly energy sources, electrical energy has been gaining increasing attention, and lithium secondary batteries in particular have been attracting attention.

[0003] Lithium secondary batteries are finding wider applications in not only small electronic devices and portable IT devices, but also electric vehicles and energy storage systems. As the range of applications for lithium secondary batteries expands, the development of new materials for higher capacity and power output is becoming increasingly important. The cathode active material for lithium secondary batteries is manufactured from precursors made from metal oxides of various components, such as nickel, cobalt, and manganese.

[0004] Although various methods have been proposed for preparing the positive electrode active material, the co-precipitation method using multi-component metal salts such as nickel, cobalt, manganese, aluminum, or zirconium as starting materials is the most economical and practical method.

[0005] There is also a batch-type device that produces precursors using the coprecipitation method. This batch-type device typically requires 1RT, which is the time it takes to fill the reaction volume with input sources to control particle growth and shape, of about 20 hours, and can produce precursors at a level of about 10% of the reaction weight based on 1RT.

[0006] As described above, the conventional batch-type apparatus uses only 70 to 80% of the internal volume of the reactor as the reaction volume, and only about 10% of the reactants are produced as precursors, resulting in a relatively low precursor productivity per unit batch.

[0007] In addition, conventional batch-type devices have problems such as increased influence of the synthesized precursor due to changes in the flow phenomenon inside the reactor as the volume between reactions changes continuously, relatively poor productivity due to batch-by-batch production, reproducibility issues due to batch division, and increased management costs, which are uneconomical. Summary of the Invention [Problem to be solved by the invention]

[0008] The technical problem to be solved by the present invention is to provide an economical apparatus for manufacturing a cathode active material precursor for a lithium secondary battery, which increases precursor productivity, minimizes the influence of changes in internal flow phenomena in a reactor on the precursor being synthesized, increases relative productivity in batch-by-batch production, and solves the problem of reproducibility due to batch fragmentation.

[0009] Another technical problem to be solved by the present invention is to provide a method for preparing a positive electrode active material precursor for a lithium secondary battery having the above-mentioned advantages. [Means for solving the problem]

[0010] An apparatus for producing a cathode active material precursor for a lithium secondary battery according to one embodiment of the present invention may include a reactor into which reactant materials are introduced and a reaction product is produced, an agitator for agitating the reactant materials, a solid-liquid separator disposed between a sidewall of the reactor and the agitator and performing solid-liquid separation in the reaction product, and a filtrate outlet disposed above the solid-liquid separator and separating and discharging a filtrate to the outside of the reactor. In one embodiment, the solid-liquid separator may include a lower portion, a middle portion, and an upper portion, and a cross-sectional area of ​​the lower portion may gradually decrease from top to bottom.

[0011] In one embodiment, the solid-liquid separation device may include a plurality of solid-liquid separation members. In one embodiment, the plurality of solid-liquid separation members may be arranged facing each other. In one embodiment, the device may include a filtrate discharge assisting portion that assists the filtrate provided from the plurality of solid-liquid separation members to move to the filtrate discharge portion.

[0012] In one embodiment, a plurality of the reactors may be connected in parallel. In one embodiment, the filtrate outlet may be arranged to be inclined downward as it becomes farther from the reactor.

[0013] In one embodiment, an apparatus for producing a cathode active material precursor for a lithium secondary battery includes a plurality of reactors including a first reactor and a second reactor, and may include: a first agitator into which reaction raw materials are introduced and which agitates the reaction raw materials and an outlet through which a portion of the reactants of the reaction raw materials are discharged; a second agitator which agitates the reactants flowing into the second reactor from the first reactor; a solid-liquid separator which is disposed between a sidewall of the first reactor and the second agitator and performs solid-liquid separation in the reaction product; and a filtrate outlet which is disposed above the solid-liquid separator and separates and discharges a filtrate to the outside of the reactor; and a second reactor which is disposed on a side of the first reactor and at a lower position than the first reactor.

[0014] In one embodiment, the second reactor may include a recovery member connected in a direction from the second reactor to the first reactor and configured to recover a portion of the filtrate. In one embodiment, a plurality of the second reactors may be connected in parallel. In one embodiment, the solid-liquid separation member may include a lower portion, a middle portion, and an upper portion, and the cross-sectional area of ​​the lower portion may gradually decrease from top to bottom.

[0015] In one embodiment, the solid-liquid separation element may be multiple. In one embodiment, the solid-liquid separation element may include a filtrate discharge auxiliary portion that assists the filtrate provided from the multiple solid-liquid separation elements to move to the filtrate discharge portion. In one embodiment, the solid-liquid separation element may include an initiation volume region and a reaction volume region, and the reaction volume region may be 70 to 90% of the internal volume of the reactor. In one embodiment, the internal volume of the solid-liquid separation element may be 20% or less of the entire reaction volume region.

[0016] In another embodiment of the present invention, a method for producing a cathode active material precursor for a lithium secondary battery may include the steps of: introducing reaction raw materials including a mixed metal salt solution and an alkaline solution into a reactor and stirring the mixture with an agitator to produce a reaction product including precursor particles; separating the reaction product into solid and liquid using a device disposed between the reactor and the agitator during the process of producing the reaction product; and discharging a residual filtrate during the solid-liquid separation. In one embodiment, the solid-liquid separation device disposed between the reactor and the agitator during the process of producing the reaction product may be performed using a plurality of solid-liquid separators.

[0017] In one embodiment, the process of producing the reaction product may include a step of producing the reaction materials in an additional reactor disposed between the reactor and the agitator prior to the step of separating solids and liquids in the reaction product. In one embodiment, the process of producing the reaction product may further include a step of performing the step of separating solids and liquids in the reaction product in parallel in a plurality of reactors disposed between the reactor and the agitator. [Effects of the Invention]

[0018] According to one embodiment of the present invention, a piping-type structure having a solid-liquid separation function is provided within a reactor, thereby increasing precursor productivity through inter-reaction solid-liquid separation and filtrate separation and discharge, minimizing the influence of changes in internal flow phenomena on the synthesized precursor, increasing relative productivity through batch-by-batch production, and solving the problem of reproducibility due to batch fragmentation, thereby providing an economical apparatus for producing a cathode active material precursor for a lithium secondary battery.

[0019] According to another embodiment of the present invention, there is provided a method for preparing a cathode active material precursor for a lithium secondary battery having the above-mentioned advantages. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 shows an apparatus for producing a positive electrode active material precursor for a lithium secondary battery according to one embodiment of the present invention. [Figure 2a] FIG. 2a shows cross-sectional views of FIG. 1 taken along lines AA', BB', and CC'. [Figure 2b] FIG. 2b shows cross-sectional views of FIG. 1 taken along lines AA', BB', and CC'. [Figure 2c] FIG. 2c shows cross-sectional views of FIG. 1 taken along lines AA', BB', and CC'. [Figure 3] FIG. 3 shows an apparatus for producing a precursor of a positive electrode active material for a lithium secondary battery according to another embodiment of the present invention. [Figure 4] FIG. 4 shows an apparatus for producing a precursor of a positive electrode active material for a lithium secondary battery according to another embodiment of the present invention. [Figure 5] FIG. 5 shows an apparatus for producing a positive electrode active material precursor for a lithium secondary battery according to another embodiment of the present invention. [Figure 6a] FIG. 6a shows a cross section of a cathode material utilizing precursors produced according to the examples and comparative examples of the present invention. [Figure 6b] FIG. 6b shows a cross section of a cathode material utilizing precursors produced according to the examples and comparative examples of the present invention. [Figure 6c]FIG. 6c shows a cross section of a cathode material utilizing precursors produced according to the examples and comparative examples of the present invention. [Figure 7a] FIG. 7a shows photographs of the results of precursor synthesis produced according to examples of the present invention and comparative examples. [Figure 7b] FIG. 7b shows photographs of the results of precursor synthesis produced according to examples of the present invention and comparative examples. DETAILED DESCRIPTION OF THE INVENTION

[0021] Terms such as first, second, and third are used to describe various parts, components, regions, layers, and / or sections, but are not limited thereto. These terms are used only to distinguish one part, component, region, layer, or section from another part, component, region, layer, or section. Therefore, a first part, component, region, layer, or section described below may be referred to as a second part, component, region, layer, or section without departing from the scope of the present invention.

[0022] The terminology used herein is merely for the purpose of referring to particular embodiments and is not intended to limit the present invention. As used herein, the singular forms "a," "an," and "the" include the plural forms unless the context clearly dictates otherwise. As used in the specification, the term "comprising" refers to the inclusion of certain properties, regions, integers, steps, operations, elements, and / or components, and does not exclude the presence or addition of other properties, regions, integers, steps, operations, elements, and / or components.

[0023] When we say that a part is "on" another part, it may be that it is immediately on top of the other part, or that there may be other parts in between. In contrast, when we say that a part is "directly on top" of another part, there are no other parts in between.

[0024] Unless otherwise defined, all terms, including technical and scientific terms, used herein have the same meaning as commonly understood by a person of ordinary skill in the art to which the present invention pertains. Terms defined in commonly used dictionaries are additionally interpreted to have a meaning consistent with the relevant technical literature and the presently disclosed content, and are not interpreted in an ideal or very formal sense unless otherwise defined.

[0025] Hereinafter, embodiments of the present invention will be described in detail, but they are presented by way of example only and are not intended to limit the present invention, which is defined only by the scope of the claims set forth below.

[0026] FIG. 1 shows an apparatus 10 for producing a positive electrode active material precursor for a lithium secondary battery according to one embodiment of the present invention.

[0027] Referring to FIG. 1, an apparatus 10 for manufacturing a positive electrode active material precursor for a lithium secondary battery according to one embodiment of the present invention includes a reactor RA into which reaction raw materials are introduced and a reaction product is produced, an agitator 12 for agitating the reaction raw materials, a solid-liquid separator 13 disposed between a side wall of the reactor RA and the agitator 12 and for performing solid-liquid separation in the reaction product, and a filtrate outlet 14 disposed above the solid-liquid separator 13 for separating and discharging the filtrate to the outside of the reactor RA.

[0028] The reactive raw materials are materials for preparing a cathode active material precursor, and may include materials such as a metal salt solution, a pH control agent, and a chelating agent. The metal salt solution is an aqueous raw material containing a transition metal for a lithium secondary battery cathode active material, and may be a metal salt material such as sulfate, nitrate, or acetate. Specifically, the metal salt solution may be, but is not limited to, an aqueous sulfate solution containing a cobalt-based, nickel-based, or manganese-based metal.

[0029] The pH control agent may be, for example, NaOH, KOH, or a mixture thereof, and the chelating agent may be, for example, an aqueous ammonia solution, an aqueous ammonium sulfate solution, or a mixture thereof.

[0030] The reaction raw materials, i.e., the metal salt solution, the pH control agent, and the chelating agent, may be introduced into the reactor RA through inlets, which are composed of a first inlet 11a, a second inlet 11b, and a third inlet 11c, respectively. In one embodiment, at least one of the first inlet 11a, the second inlet 11b, and the third inlet 11c may be shared, and an inert gas may be introduced to carry out the reaction. The inert gas may be, for example, nitrogen gas, argon gas, or a mixture thereof, as a non-limiting example.

[0031] The reactor RA may contain the metal salt solution and the pH control agent, which react and consume to generate primary particles. The chelating agent may aggregate the primary particles to generate secondary particles. The reactor RA may be controlled to distribute the reactants uniformly within the reactor RA.

[0032] The agitator 12 disposed within the reactor RA can agitate the reactants. Specifically, the agitator 12 is a component that generates a fluid flow and increases the degree of mixing of the reactants. The agitated reactants react with each other, react, and consume, producing precursor particles and a reaction filtrate that exist as a homogeneous phase within the reactor RA. Specifically, the reactants, such as metal salts and pH control agents, can react with each other and consume within the reactor. For example, a metal salt, such as a metal sulfate, and a pH control agent, such as sodium hydroxide, can be mixed, and the metal hydroxide and sodium sulfate can react with each other and consume.

[0033] In one embodiment, the reactor RA may include at least one baffle (not shown) that induces a vortex flow inside the reactor RA. Specifically, the baffle may be a member that acts as a baffle against the fluid flow inside the reactor RA, forming a vortex flow to facilitate mixing of reactants with each other and to help the secondary precursor particles to be uniformly distributed in the reactants.

[0034] In one embodiment, the reactor RA may include an initiation volume region (between the bottom of the RA and line BB') and a reaction volume region (between the bottom of the RA and line AA'). The initiation volume region refers to a volume that can exhibit a fluid flow effect during the reaction. After the reactor RA is filled with raw materials, the raw materials begin to react due to a vortex induced by a device such as an agitator 12. The reaction volume region refers to a region where the reaction occurs from the initiation volume region, and the reactants increase and are discharged. This region is accompanied by a volume change as the raw materials react, affecting the growth of the precursor due to the change in flow inside the reactor RA. A higher ratio of the reaction volume region can increase precursor production.

[0035] In one embodiment, the reaction volume region may be 70 to 90% of the internal volume of the reactor. Specifically, the reaction volume region may be 80 to 90% of the internal volume of the reactor. By ensuring the reaction volume region, there is an advantage that the precursor production amount per reaction is significantly increased.

[0036] The solid-liquid separation member 13 is disposed between the side wall of the reactor RA and the agitator 12, and separates the solid and liquid of the reaction product. Specifically, the solid-liquid separation member 13 may be disposed along the circumferential direction of the side wall of the reactor RA. The solid and liquid separated by the solid-liquid separation member 13 may be precursor particles and filtrate, respectively, of the reaction product obtained through a coprecipitation reaction.

[0037] In one embodiment, the solid-liquid separating member 13 may be arranged in place of the baffles described above. For example, in the case of a conventional device, four baffles may be arranged facing each other, but in the present invention, at least one of the baffles may be replaced by the solid-liquid separating member 13.

[0038] The solid-liquid separator 13 is disposed within the reactor RA and can suppress the flow of reactants produced by the reaction of the raw materials, enabling continuous solid-liquid separation during the coprecipitation reaction, significantly increasing the productivity of the reactants, such as precursors, per unit area. Specifically, the solid-liquid separator 13 suppresses fluid flow within the structure to induce solid-liquid separation, and outside the structure, it acts as a vortex generator in the fluid flow generated by the agitator 12, promoting homogenization. More specifically, after abundant particle nuclei are generated in the initial volume of the reactor RA at the beginning of the reaction, solid-liquid separation occurs within the solid-liquid separator 13 as they reach the reaction volume, and a filtrate corresponding to each phase can be discharged.

[0039] By disposing the solid-liquid separator 13 within the reactor RA, the reactants produced within the reactor RA can be separated into solid and liquid in real time using the solid-liquid separator 13, and the separated reaction filtrate can be removed, thereby securing additional reaction volume. This process can be repeated in real time, increasing the solid-liquid ratio of the total particles produced within the reactor RA. Specifically, by disposing the solid-liquid separator 13 within the reactor RA, additional reaction volume can be secured, thereby increasing the productivity of the reaction product, e.g., the cathode active material precursor, improving the sphericity of the cathode active material precursor, and ensuring the crystal orientation of the cathode active material precursor. This allows for the formation of an oriented crystalline phase during the conversion of the cathode active material precursor into a cathode active material, resulting in the production of a high-performance cathode active material.

[0040] A filtrate discharge port 14 that separates and discharges the filtrate to the outside of the reactor RA may be disposed on the solid-liquid separation member 13. The filtrate discharge port 14 is disposed on the solid-liquid separation member 13, and can discharge a liquid filtrate that is the reactants separated by the solid-liquid separation member 13 and from which solid precursor particles have been removed. Specifically, the flow of the reactants generated in the reactor RA is suppressed within the solid-liquid separation member 13, so that the solid precursor particles, which have a high specific gravity in the reactants, move downward in the solid-liquid separation member 13, and the relatively light reaction filtrate is concentrated at the upper part of the solid-liquid separation member 13.

[0041] At this time, the filtrate is removed in real time through the filtrate outlet 14 and discharged to the outside, ensuring a reaction volume in a corresponding area and inducing continuous growth of precursor particles, ultimately significantly increasing the precursor production amount per reaction. Specifically, after the filtrate reaches the effective reaction volume in which the target precursor particles are formed, an amount corresponding to the volume generated by the input raw materials may overflow the solid-liquid separator 13 and be discharged through the filtrate outlet 14.

[0042] In one embodiment, the filtrate discharge port 14 may be disposed so as to incline downward as it becomes farther from the reactor RA. By disposing the filtrate discharge port 14 at a predetermined angle, the remaining filtrate can be easily discharged to the outside. In one embodiment, the filtrate discharge port 14 may be angled at an angle of 0 to 90°, specifically 15 to 90°, more specifically 45 to 90°, based on the extension direction of the sidewall of the reactor RA and a direction perpendicular to the extension direction. By satisfying this range, the filtrate can be easily discharged.

[0043] In one embodiment, the filtrate outlet 14 may be connected to a filtrate reservoir (not shown) for storing the filtrate. The filtrate is stored in the filtrate reservoir, and the stored filtrate can be reused, thereby providing an economical apparatus for manufacturing a cathode active material precursor for a lithium secondary battery.

[0044] 2a to 2c are front views of FIG. 1 cut along lines AA', BB', and CC', respectively.

[0045] Referring to Figures 2a to 2c, Figure 2a shows a front view of the solid-liquid separation member cut along line AA' in Figure 1, specifically, a member including the upper portion 13T of the solid-liquid separation member and the filtrate discharge port 14; Figure 2b shows a front view of the solid-liquid separation member cut along line BB' in Figure 1, specifically, a lower portion 13B of the solid-liquid separation member; and Figure 2c shows a front view of the solid-liquid separation member cut along line CC' in Figure 1, specifically, a middle portion 13M of the solid-liquid separation member.

[0046] The solid-liquid separator 13 includes an upper portion 13T, a middle portion 13M, and a lower portion 13B, and the cross-sectional area of ​​the lower portion 13B may gradually decrease from top to bottom. The solid-liquid separator 13 serves to prevent the flow of reactants generated by the agitator 12 from being transmitted to the interior of the solid-liquid separator. Since the cross-sectional area of ​​the lower portion 13B of the solid-liquid separator gradually decreases from top to bottom, the influence of the flow generated by the agitator 12 can be effectively suppressed. Specifically, the cross-sectional area of ​​the lower portion 13B of the solid-liquid separator gradually decreases from top to bottom, creating a weak negative pressure in the lower portion 13B of the solid-liquid separator. This draws the precursors precipitated inside the solid-liquid separator 13 into the reactor RA, inducing further reactions and improving the productivity of the synthesized precursors.

[0047] In one embodiment, the internal volume of the solid-liquid separator 13 may be 25% or less of the reaction volume region. Specifically, the internal volume of the solid-liquid separator 13 may satisfy 20% or less of the total reaction volume region. The internal volume ratio of the solid-liquid separator 13 described above is a value calculated based on a reaction design with a reaction time RT of 5 to 20 hours. For example, the internal volume of the solid-liquid separator 13 may be 15 to 25% based on a reaction time RT of 5 hours, or may be 5 to 15% based on a reaction time RT of 10 hours. Thus, the shorter the reaction time RT in a coprecipitation reaction, the higher the productivity. Therefore, the internal volume of the solid-liquid separator may be 20% or less of the total reactor volume when the reaction time RT is set to a short reaction time RT of 5 hours.

[0048] When the internal volume of solid-liquid separator 13 satisfies the above range, the proportion of the reaction volume region can be efficiently increased, thereby maximizing the production amount of the cathode active material precursor. If the internal volume of solid-liquid separator 13 is outside the above range, the effect of increasing the proportion of the reaction volume region can be insufficient, and the function of preventing the flow of the formed reactants from being transmitted inside the solid-liquid separator can be impaired.

[0049] FIG. 3 shows an apparatus for producing a precursor of a positive electrode active material for a lithium secondary battery according to another embodiment of the present invention.

[0050] 3, in one embodiment, a plurality of solid-liquid separation members 13 may be included. By including a plurality of solid-liquid separation members 13, the ratio of the reaction volume region may be increased, thereby increasing the productivity of precursor particles.

[0051] In one embodiment, the plurality of solid-liquid separation members 13 may be arranged facing each other. The plurality of solid-liquid separation members 13 may also be arranged in pairs facing each other. For example, the plurality of solid-liquid separation members 13 may be arranged in four regions facing each other, replacing baffles. By arranging the plurality of solid-liquid separation members 13 in pairs facing each other, a stable reaction region can be secured, solid-liquid separation efficiency can be increased in real time, and additional reaction volume regions can be easily secured, thereby increasing precursor productivity.

[0052] In one embodiment, when a plurality of solid-liquid separation members 13 are disposed, a filtrate discharge auxiliary unit 14H may be further included. Specifically, the filtrate discharge auxiliary unit 14H may be disposed above the solid-liquid separation members 13 and connected to the filtrate discharge unit 14. More specifically, the filtrate discharge auxiliary unit 14H may be configured to be connected to the filtrate discharge unit 14 and may be a member that helps to facilitate the movement of the filtrate provided from the plurality of solid-liquid separation members 13 to the filtrate discharge unit 14.

[0053] In one embodiment, the filtrate discharge auxiliary unit 14H may be horizontally connected to the upper ends of the solid-liquid separators 13 and may function as a pipe. Specifically, the filtrate discharge auxiliary unit 14H is a pipe that transfers the solid-liquid separated filtrate from the upper ends of the plurality of solid-liquid separators 13 to the filtrate discharge unit 14. In one embodiment, the filtrate discharge auxiliary unit 14H may have a sealed structure in an area other than a portion that contacts the upper ends of the solid-liquid separators 13. Specifically, the filtrate discharge auxiliary unit 14H may have a sealed structure in an area other than the upper ends of the solid-liquid separators 13 to prevent the flow of reactants.

[0054] In one embodiment, the filtrate discharge auxiliary unit 14H may have a circular or rectangular pipe shape. It may have a donut shape connected along the outer wall of the reactor, connected to each solid-liquid separation member 13 and filtrate discharge port 14, and the remaining area may be sealed. Specifically, the edge of the filtrate discharge auxiliary unit 14H may be a member corresponding to the upper portion 13T of the solid-liquid separation member 13. The inclusion of the filtrate discharge auxiliary unit 14H eliminates the need for additional components requiring separate power and serves as a pipe for discharging the filtrate, resulting in economical advantages.

[0055] FIG. 4 shows an apparatus 10'' for producing a positive electrode active material precursor for a lithium secondary battery according to another embodiment of the present invention.

[0056] 4, the apparatus 10″ for producing a cathode active material precursor for a lithium secondary battery may be configured with a plurality of reactors. In one embodiment, the apparatus 10″ for producing a cathode active material precursor for a lithium secondary battery, including a first reactor RA1 and a second reactor RA2, may include the first reactor RA1 being a typical batch coprecipitation reactor that does not include a solid-liquid separator 13, and the second reactor RA2 including at least one solid-liquid separator 13 and a filtrate outlet 14′.

[0057] The second reactor RA2 may include a solid-liquid separator 13 disposed between the sidewall of the second reactor RA2 and the agitator 12′ to separate the reactant provided from the first reactor RA1 through the outlet 14 into solid and liquid in the reaction product, and a filtrate discharger 14′ disposed above the solid-liquid separator 13 to separate and discharge the filtrate outside the second reactor RA2.

[0058] In one embodiment, the first reactor RA1 may include a first agitator 12 that receives and agitates reactant materials and an outlet 14 that transfers reactants generated from the reactant materials to the second reactor RA2. The second reactor RA2 may include a second agitator 12' that agitates the reactants flowing from the first reactor into the second reactor RA2, a solid-liquid separator 13 that is disposed between the sidewall of the second reactor RA2 and the second agitator 12' and performs solid-liquid separation in the reaction product, and a filtrate outlet 14 that is disposed above the solid-liquid separator 13 and separates and discharges the filtrate to the outside of the second reactor RA2. Detailed descriptions of each component may be found in the above-described descriptions of the components of the apparatus 10 for preparing a cathode active material precursor for a lithium secondary battery to the extent that they do not contradict each other.

[0059] Specifically, the apparatus 10″ for producing a positive electrode active material precursor for a lithium secondary battery includes two reactors. A reaction may be primarily carried out in the first reactor RA1, and then an additional reaction including solid-liquid separation may be carried out in the second reactor RA2. By including an additional reaction including solid-liquid separation in the second reactor RA2, the solid content can be advantageously increased.

[0060] In one embodiment, the first reactor RA1 may be disposed at a higher position than the second reactor RA2. By disposing the first reactor RA1 at a higher position than the second reactor RA2, the reactants produced in the first reactor RA1 can be easily transferred to the second reactor RA2.

[0061] In one embodiment, the apparatus 10″ for producing a cathode active material precursor for a lithium secondary battery can maintain a state in which the volume of the raw materials input into the reactor and the volume of the reaction filtrate are equal to each other from the middle of the reaction onward. Specifically, when the reaction volumes of the first reactor RA1 and the second reactor RA2 have both reached their respective limits, the total volume of the reaction filtrate discharged from the solid-liquid separator 13 and the filtrate outlet 14 may be equal to the total volume of the raw materials input into the first reactor RA1. In this way, the apparatus 10″ for producing a cathode active material precursor for a lithium secondary battery has the advantage of being unconstrained by a limited reaction volume and capable of sustaining the reaction while increasing the solid-liquid ratio for a desired reaction time.

[0062] In one embodiment, a recovery member 15 may be included that is connected from the second reactor RA1 to the first reactor RA2 and recovers concentrated reactants with an increased solid-liquid ratio. Specifically, the first reactor RA1 is the main reaction zone where reactants form or grow particles through coprecipitation, and the recovery member 15 circulates the reactants, the solid-liquid ratio of which has been increased through solid-liquid separation in the second reactor RA2, to the first reactor to induce additional growth reactions.

[0063] FIG. 5 shows an apparatus 10''' for producing a precursor of a positive electrode active material for a lithium secondary battery according to another embodiment of the present invention.

[0064] Referring to FIG. 5 , a plurality of apparatuses 10′″ for preparing a cathode active material precursor for a lithium secondary battery, each including the second reactor RA2 described above, may be connected in parallel. In one embodiment, the apparatus 10′″ for preparing a cathode active material precursor for a lithium secondary battery may include a reactor RA, for example, the second reactor RA2 described above, into which reactant materials are introduced and a reaction product is produced; an agitator 12 for agitating the reactant materials; a solid-liquid separator 13 disposed between the sidewall of the reactor RA and the agitator 12 and performing solid-liquid separation in the reaction product; and a filtrate outlet 14 disposed above the solid-liquid separator 13 and for separating and discharging the filtrate to the outside of the reactor RA. In one embodiment, the apparatus 10′″ for preparing a cathode active material precursor for a lithium secondary battery may include an auxiliary filtrate discharge unit 14H. The detailed description of the configuration of the above-described reactors is the same as that of FIGS. 1 to 4 to the extent not inconsistent.

[0065] In one embodiment, a plurality of second reactors RA2 are connected in parallel on the same line, and each second reactor RA2 circulates reactants with an increased solid-liquid ratio through solid-liquid separation using recovery members 15, 15', and 15'' to induce an additional growth reaction. At this time, filtrate outlets 14, 14', and 14'' disposed at the upper ends of solid-liquid separation members 13, 13', and 13'' can independently discharge the reaction filtrate to the outside. By arranging a plurality of second reactors RA2 in parallel, the reactants in the plurality of reactors can be homogenized by passing through the other reactors, thereby increasing productivity. In one embodiment, the apparatus 10''' for preparing a cathode active material precursor for a lithium secondary battery may further include a first reactor RA1 disposed at a higher position than the plurality of second reactors RA2. The detailed description of the first reactor RA1 is the same as that of FIG. 4, as long as it is not inconsistent with the description of FIG. 4.

[0066] According to another embodiment of the present invention, a method for preparing a positive electrode active material precursor for a lithium secondary battery may include the steps of: introducing reaction raw materials including a mixed metal salt solution and an alkaline solution into a reactor and stirring the raw materials with an agitator to generate a reaction product including precursor particles; separating solid and liquid in the reaction product using a device disposed between the reactor and the agitator during the process of generating the reaction product; and discharging a remaining filtrate after the solid-liquid separation.

[0067] The step of adding reactant materials including a metal solution and an alkaline solution to a reactor and stirring them with an agitator to produce a reaction product including precursor particles may be the same as the step of adding reactant materials including a metal solution, an alkaline solution, and a substance such as a chelating agent to a reactor and stirring them with an agitator to produce a reaction product including precursor particles. Detailed descriptions of the reactant materials, the reactor, the agitator, and the reaction product are the same as those of the apparatus for producing a cathode active material precursor for a lithium secondary battery described above to the extent not inconsistent.

[0068] During the process of producing the reaction product, a step of separating solid and liquid in the reaction product, which is arranged between the reactor and the agitator, can separate precursor particles and filtrate in the reaction product through a solid-liquid separating element arranged in the reactor.

[0069] In one embodiment, in the process of producing the reaction product, a step of separating solid and liquid in the reaction product may be performed by a plurality of solid-liquid separators disposed between the reactor and the agitator. A plurality of solid-liquid separators may be disposed within the reactor. By disposing a plurality of solid-liquid separators, the reaction volume ratio can be increased, thereby increasing precursor productivity. For a detailed description of the operation principle of the solid-liquid separator, reference may be made to the above-described solid-liquid separator to the extent that it does not contradict.

[0070] In the step of performing solid-liquid separation, the remaining filtrate is discharged by restricting the flow of the reactants generated in the reactor through the solid-liquid separator within the solid-liquid separator, so that solid precursor particles with a high specific gravity in the reactants move toward the bottom of the solid-liquid separator, and the relatively light reaction filtrate is concentrated at the top of the solid-liquid separator.

[0071] At this time, the filtrate is removed in real time through a filtrate outlet and discharged to the outside, ensuring a reaction volume in a corresponding area and inducing continuous growth of precursor particles, ultimately significantly increasing the precursor production amount per reaction. Specifically, after the filtrate reaches the effective reaction volume in which the target precursor particles are formed, an amount corresponding to the volume generated by the input raw material may be discharged by overflowing through a solid-liquid separator via the filtrate outlet. A detailed description of this is the same as that of the filtrate outlet described above to the extent that it does not contradict.

[0072] In one embodiment, the process of producing the reaction product may include a step of producing a reactant from the raw materials in an additional reactor disposed between the reactor and the agitator and prior to the step of separating the solid and liquid in the reaction product. The additional reactor refers to the first reactor RA1 in the apparatus for producing a cathode active material precursor for a lithium secondary battery described above, and the description of the first reactor RA1 may be referenced to the extent not inconsistent. By including a step of producing a reactant in the additional reactor, the reactant is produced in the additional reactor, and then solid-liquid separation is performed in the reactor, thereby concentrating the solid-liquid mixture and increasing precursor productivity.

[0073] In one embodiment, during the process of producing the reaction product, the step of separating the solid and liquid in the reaction product, which is disposed between the reactor and the agitator, may further include a step of performing the solid-liquid separation in a plurality of reactors in parallel. By disposing a plurality of reactors including the solid-liquid separation step and performing the reaction in the plurality of reactors in parallel, the productivity of the synthesized precursor can be improved. [Example]

[0074] The following examples are merely one embodiment of the present invention, and the present invention is not limited to the following embodiments.

[0075] <Experimental Example>

[0076] <Creating cathode material through growth of precursor particles> 6a to 6c show particle photographs of cross sections of the precursors produced in the examples and comparative examples of the present invention as cathode materials.

[0077] Referring to FIGS. 6a to 6c, FIG. 6a is a comparative example of the present invention and shows a conventional batch-type apparatus, FIG. 6b shows a circulating process according to one embodiment of the present invention, and FIG. 6c shows a cross-sectional SEM image of a cathode material obtained by converting a precursor produced by using a circulating concentration process according to one embodiment of the present invention.

[0078] The product shape and cross section in Figure 6a show that the sphericity and orientation are relatively lower than those in Figures 6b and 6c. The products in Figures 6b and 6c demonstrate that it is possible to manufacture high-performance cathode active materials with excellent sphericity and crystal orientation.

[0079] <Results of precursor synthesis> Table 1 below shows the results of precursor synthesis according to the configurations of examples and comparative examples of the present invention. The comparative example in Table 1 below is a conventional apparatus for producing a cathode active material precursor that does not include a separate solid-liquid separator or filtrate outlet, Example 1 is an apparatus for producing a cathode active material precursor for a lithium secondary battery that includes a solid-liquid separator and a filtrate outlet, and Example 2 is an apparatus for producing a cathode active material precursor for a lithium secondary battery that includes a first reactor that does not include a solid-liquid separator or filtrate outlet and a second reactor that includes a solid-liquid separator and a filtrate outlet.

[0080] [Table 1]

[0081] 7a and 7b show photographs of the synthesis results of precursors produced in an example and a comparative example of the present invention. Fig. 7a shows a photograph of the synthesis results of the precursor of the comparative example, and Fig. 7b shows a photograph of the synthesis results of the precursor of Example 2. Referring to Table 1 and Figs. 7a and 7b, it can be seen that the physical properties of the product, such as particle size distribution, fine particle state, and sphericity, were improved.

[0082] The present invention is not limited to the above-described embodiments, and can be manufactured in various different forms, and a person skilled in the art to which the present invention pertains should understand that the present invention can be embodied in other specific forms without changing the technical concept or essential characteristics of the present invention. Therefore, the above-described embodiments should be understood to be illustrative in all respects and not limiting.

Claims

1. a reactor into which reaction raw materials are introduced and a reaction product is produced; a stirrer for stirring the reaction raw materials; a solid-liquid separating member disposed between the side wall of the reactor and the agitator, for performing solid-liquid separation in the reaction product; and the solid-liquid separation member is disposed above the reactor, and the filtrate outlet is configured to separate and discharge the filtrate to the outside of the reactor.

2. 2. The apparatus for manufacturing a positive electrode active material precursor for a lithium secondary battery according to claim 1, wherein the solid-liquid separation member includes a lower portion, a middle portion, and an upper portion, and a cross-sectional area of ​​the lower portion gradually decreases from top to bottom.

3. The apparatus for producing a positive electrode active material precursor for a lithium secondary battery according to claim 1 , wherein the solid-liquid separation member includes a plurality of solid-liquid separation members.

4. The apparatus for producing a positive electrode active material precursor for a lithium secondary battery according to claim 3 , wherein the plurality of solid-liquid separation members are arranged facing each other.

5. 2. The apparatus for preparing a positive electrode active material precursor for a lithium secondary battery according to claim 1, further comprising a filtrate discharge assisting unit for assisting the filtrate provided from the plurality of solid-liquid separators to move to a filtrate discharge unit.

6. The apparatus for preparing a positive electrode active material precursor for a lithium secondary battery according to claim 1 , wherein a plurality of the reactors are connected in parallel.

7. The apparatus for preparing a positive electrode active material precursor for a lithium secondary battery according to claim 1 , wherein the filtrate outlet is disposed so as to be inclined downward as it becomes farther from the reactor.

8. The present invention relates to an apparatus for producing a positive electrode active material precursor for a lithium secondary battery, which is configured with a plurality of reactors including a first reactor and a second reactor, The first reactor is charged with reaction raw materials, and includes a first agitator for agitating the reaction raw materials and an outlet for discharging a part of the reactants of the reaction raw materials, a second agitator that agitates the reactants flowing into the second reactor from the first reactor; a solid-liquid separator that is disposed between a sidewall of the first reactor and the second agitator and performs solid-liquid separation in the reaction product; and a filtrate outlet that is disposed above the solid-liquid separator and separates and discharges a filtrate to the outside of the reactor, An apparatus for producing a positive electrode active material precursor for a lithium secondary battery, comprising: the second reactor, which is disposed on a side of the first reactor and at a lower position than the first reactor.

9. 9. The apparatus for producing a positive electrode active material precursor for a lithium secondary battery according to claim 8, further comprising a recovery member connected from the second reactor to the first reactor, the recovery member recovering a portion of the filtrate.

10. The apparatus for preparing a positive electrode active material precursor for a lithium secondary battery according to claim 8 , wherein a plurality of the second reactors are connected in parallel.

11. 9. The apparatus for manufacturing a positive electrode active material precursor for a lithium secondary battery according to claim 8, wherein the solid-liquid separation member includes a lower portion, a middle portion, and an upper portion, and a cross-sectional area of ​​the lower portion gradually decreases from top to bottom.

12. The apparatus for producing a positive electrode active material precursor for a lithium secondary battery according to claim 11 , wherein the solid-liquid separation member includes a plurality of solid-liquid separation members.

13. 13. The apparatus for preparing a positive electrode active material precursor for a lithium secondary battery according to claim 12, further comprising a filtrate discharge assisting unit for assisting the filtrate provided from the plurality of solid-liquid separators to move to a filtrate discharge unit.

14. the solid-liquid separation member includes an initiation volume region and a reaction volume region; 12. The apparatus for preparing a positive electrode active material precursor for a lithium secondary battery according to claim 11, wherein the reaction volume region is 70 to 90% of the internal volume of the reactor.

15. 12. The apparatus for producing a positive electrode active material precursor for a lithium secondary battery according to claim 11, wherein the internal volume of the solid-liquid separation member is 20% or less of the entire reaction volume area.

16. charging reaction raw materials including a mixed metal salt solution and an alkaline solution into a reactor and stirring them with a stirrer to generate a reaction product including precursor particles; A step of separating solids and liquids in the reaction product, the step being disposed between the reactor and the agitator during the process of generating the reaction product; and The method for producing a positive electrode active material precursor for a lithium secondary battery includes a step of discharging a residual filtrate in the step of performing solid-liquid separation.

17. 17. The method for producing a positive electrode active material precursor for a lithium secondary battery according to claim 16, wherein, in the process of producing the reaction product, in the step of separating solid and liquid in the reaction product, the step of separating solid and liquid is performed by a plurality of solid-liquid separation members disposed between the reactor and the agitator.

18. In the process of producing the reaction product, a step of separating solids and liquids in the reaction product is performed by disposing a separator between the reactor and the agitator, The method for producing a positive electrode active material precursor for a lithium secondary battery according to claim 16, comprising the step of producing a reactant from the reaction raw materials in an additional reactor.

19. 20. The method for producing a positive electrode active material precursor for a lithium secondary battery according to claim 18, further comprising: a step of separating a solid from a liquid in the reaction product, the step being performed in parallel in a plurality of reactors disposed between the reactor and the agitator during the process of producing the reaction product.

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