Positive electrode active material precursor for lithium secondary battery and method for producing same

Abstract

The present invention relates to a positive electrode active material precursor comprising secondary particles formed by the aggregation of a plurality of primary particles, wherein the primary particles include particles having a polyhedral structure, the secondary particles have a spherical structure, and the primary particle factor represented by mathematical formula 1 is 11-15%.

Description

Precursor of positive electrode active material for lithium secondary battery and method for manufacturing same Cross-citation with related applications This application claims the benefit of priority to Korean Patent Application No. 10-2023-0121341, filed September 12, 2023, and Korean Patent Application No. 10-2024-0116034, filed August 28, 2024, the entire contents of which are incorporated herein by reference. Technology field The present invention relates to a positive electrode active material precursor for a lithium secondary battery and a method for producing the positive electrode active material precursor. Recently, with the advancement of technology such as electric vehicles, the demand for high-capacity secondary batteries is increasing, and accordingly, research on cathodes using high-nickel (High Ni) cathode active materials with excellent capacity characteristics is being actively conducted. Since the high-nickel cathode active material uses a co-precipitation method to manufacture it, the manufactured high-nickel cathode active material has the form of secondary particles in which primary particles are aggregated. However, the active material in the form of secondary particles has the disadvantage that microcracks occur in the secondary particles during long-term charge / discharge processes, causing side reactions. In addition, when the electrode density is increased to improve energy density, the secondary particles cause structural collapse, which reduces the active material and electrolyte, resulting in a decrease in energy density and a decrease in life characteristics. To address the issues inherent in high-nickel cathode active materials in the form of secondary particles, single-crystal high-nickel cathode active materials have recently been developed. Single-crystal high-nickel cathode active materials have the advantage of preventing particle collapse even when increasing electrode density to achieve high energy density. However, relatively high sintering temperatures and times are required to manufacture single-crystal high-nickel cathode active materials. However, increasing sintering temperatures and times increases impurities, and decreasing sintering temperatures and times to reduce impurities prevents proper particle formation. Therefore, there is a need for the development of a cathode active material precursor that is easy to single-particle while reducing the sintering temperature and sintering time, and a method for manufacturing the same. The problem to be solved by the present invention is to provide a positive electrode active material precursor that is easy to be single-particleized. Another problem to be solved by the present invention is to provide a method for manufacturing the positive electrode active material precursor. In order to solve the above problem, the present invention provides a positive electrode active material precursor and a method for producing the positive electrode active material precursor. [1] The present invention provides a positive electrode active material precursor which is a secondary particle formed by aggregating a plurality of primary particles, wherein the primary particles include particles having a polyhedral structure, the secondary particles are particles having a spherical structure, and the positive electrode active material precursor has a primary particle factor of 11% to 15%, as expressed by the following mathematical formula 1. [Mathematical Formula 1] Primary particle factor = perimeter of primary particle (㎛) / average particle diameter of secondary particle (D 50 )(㎛) Х 100(%) [2] In the present invention, in the above [1], the BET specific surface area of ​​the positive electrode active material precursor is 1.5 m 2 / g to 5.0 m 2 / g provides a positive electrode active material precursor. [3] In the present invention, in the above [1] or [2], the tap density of the positive electrode active material precursor is 1.4 g / cm 3 2.6 g / cm 3 A precursor for a positive electrode active material is provided. [4] The present invention relates to a method for producing a cathode active material precursor having a span value [(D] in any one of the above [1] to [3]. 90 -D 10 ) / D 50 ] provides a positive electrode active material precursor having a molecular weight of 0.4 to 0.8. [5] The present invention, in any one of the above [1] to [4], the positive electrode active material precursor is D 10 This provides a positive electrode active material precursor having a diameter of 2.2 μm to 4.2 μm. [6] The present invention, in any one of [1] to [5], wherein the positive electrode active material precursor has an average particle diameter (D 50 ) provides a positive electrode active material precursor having a diameter of 3.0 ㎛ to 5.5 ㎛. [7] The present invention, in any one of the above [1] to [6], the positive electrode active material precursor is D 90 This provides a positive electrode active material precursor having a diameter of 4.8 μm to 6.8 μm. [8] The present invention provides a positive electrode active material precursor according to any one of the above [1] to [7], wherein the positive electrode active material precursor contains nickel among transition metals at 60 mol% or more. [9] The present invention provides a positive electrode active material precursor represented by the following chemical formula 1 in any one of the above [1] to [8]: [Chemical Formula 1] [Ni x Co y M 1 z M 2 w ](OH)2 In the above chemical formula 1, 0.6≤x<1, 0 <y<0.4, 0<z<0.4, 0≤w<0.4이고, M 1 is at least one selected from the group consisting of Mn and Al, and M 2 is at least one selected from the group consisting of Zr, B, Ce, V, Fe, Zn, Si, Ga, Sn, Hf, W, Mo, Cr, Nb, Mg, Hf, Ta, La, Ti, Sr, Ba, F, P, S and Y.

[0010] The present invention provides a positive electrode active material precursor according to any one of the above [1] to [9], wherein the positive electrode active material precursor comprises particles having a polyhedral structure at 70% or more based on the total number of primary particles.

[0011] The present invention provides a method for producing a positive electrode active material precursor, comprising: (A) a step of introducing a reaction solution containing a transition metal-containing solution, an ammonium ion-containing solution, and a basic aqueous solution into a reactor having a filter installed therein; (B) a step of continuously introducing the transition metal-containing solution, the ammonium ion-containing solution, and the basic aqueous solution into the reactor while maintaining the pH of the reaction solution, thereby performing a cathode active material precursor particle growth reaction; and (C) a step of continuously performing the cathode active material precursor particle growth reaction while continuously discharging only the reaction waste solution to the outside of the reactor through a filter device inside the reactor when the reactor is full; wherein in step (B), the ammonium ion-containing solution is introduced so that the molar ratio of the transition metal and the ammonium ion is 1:0.1 or more and 1.0 or less, and the basic aqueous solution is introduced so that the molar ratio of the transition metal and the hydroxide ion is 1:1.5 or more and 2.5 or less.

[0012] The present invention provides a method for producing a positive electrode active material precursor, wherein the transition metal-containing solution in the above

[0011] contains nickel in an amount of 60 mol% or more among the transition metals.

[0013] The present invention provides a method for producing a positive electrode active material precursor in the above

[0011] or

[0012] , wherein the pH of the reaction solution of steps (A) and (B) is 11 to 13.

[0014] The present invention provides a method for manufacturing a positive electrode active material precursor, wherein in any one of the above

[0011] to

[0013] , in step (B), an ammonium ion-containing solution is added so that the molar ratio of the transition metal and the ammonium ion is 1:0.4 or more and 0.6 or less, and an alkaline aqueous solution is added so that the molar ratio of the transition metal and the hydroxide ion is 1:1.9 or more and 2.1 or less. When the positive electrode active material precursor of the present invention is reacted with lithium to manufacture a positive electrode active material, lithium desorption is suppressed, reducing the phenomenon of residual lithium remaining as an impurity and single particles are easily formed even at a low firing temperature. Therefore, the positive electrode active material precursor of the present invention and the method for manufacturing the same can be usefully used in the manufacture of a single-particle positive electrode active material. The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the contents of the invention described above, serve to further understand the technical idea of ​​the present invention, and therefore, the present invention should not be interpreted as being limited to matters described in such drawings. Figure 1 is an example of a reactor in which the method for manufacturing a positive electrode active material of the present invention can be performed. Figure 2 is an SEM photograph of the positive electrode active material precursor manufactured in Example 1. Figure 3 is an SEM photograph of the positive electrode active material precursor manufactured in Comparative Example 1. Figure 4 is an SEM photograph of the positive electrode active material precursor manufactured in Comparative Example 2. Figure 5 is a segmentation image of a primary particle obtained using an SEM image of a lithium transition metal oxide manufactured using the positive electrode active material precursor manufactured in Example 1. Figure 6 is an SEM photograph of a lithium transition metal oxide manufactured using the positive electrode active material precursor manufactured in Example 1. Figure 7 is an SEM photograph of a lithium transition metal oxide manufactured using the positive electrode active material precursor manufactured in Comparative Example 1. Figure 8 is an SEM photograph of a lithium transition metal oxide manufactured using the positive electrode active material precursor manufactured in Comparative Example 2. Hereinafter, the present invention will be described in more detail. Terms or words used in this specification and claims should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted as meanings and concepts that conform to the technical idea of ​​the present invention, based on the principle that the inventor can appropriately define the concept of the term to explain his or her own invention in the best way. In the present invention, the term 'primary particle' means the smallest particle unit that can be distinguished as a single lump when observing the cross-section of a positive electrode active material through a scanning electron microscope (SEM), and may be composed of multiple crystal grains. In the present invention, the term "secondary particle" refers to a secondary structure formed by the aggregation of multiple primary particles. The average particle diameter of the secondary particles can be measured using a particle size analyzer. In the present invention, the term 'single particle' may be used instead of the term 'single particle form' or 'single particle type', and means a form that is in contrast to a secondary particle form formed by agglomeration of hundreds of primary particles. In addition, in the present invention, the term 'single particle positive electrode active material' or 'lithium transition metal oxide in single particle form' means a positive electrode active material or lithium transition metal active material composed of 50 or fewer single crystal particles, in contrast to a positive electrode active material in the form of secondary particles formed by agglomeration of hundreds of primary particles. Typically, a single crystal particle refers to a particle whose entire sample consists of a single grain or grain region. The term "grain" or "grain region" refers to a region within the sample where atoms are continuously and periodically arranged in one direction. The grain can be analyzed using an electron backscatter diffraction (ESBD) analyzer. In the present invention, the term 'D 10 ', 'Average particle diameter (D 50 )' and 'D 90 ' means the particle size at 10%, 50% and 90% points of the volume cumulative distribution according to particle size, respectively. The above average particle size is calculated by dispersing the powder to be measured in a dispersion medium, introducing it into a commercially available laser diffraction particle size measuring device (e.g., S3500 from Microtrac), and measuring the difference in diffraction pattern according to particle size when the particles pass through the laser beam, and calculating the particle size at the points where the particle diameter is 10%, 50% and 90% of the volume cumulative distribution according to particle size in the measuring device, respectively, thereby obtaining D 10 , D 50 and D 90 can be measured. In the present invention, the term 'segmentation image' is an image segmented into individual particle units, and can be obtained by a method including a first step of obtaining an SEM image by analyzing a positive electrode active material powder using a scanning electron microscope, and a second step of removing the edges of individual particles from the SEM image using a computer image processing technique, then detecting seeds or contours of individual particles, and using the same to obtain an image segmented into individual particle units. The positive electrode active material precursor of the present invention is a positive electrode active material precursor that is a secondary particle formed by aggregating a plurality of primary particles, wherein the primary particles include particles having a polyhedral structure, the secondary particles are particles having a spherical structure, and the primary particle factor represented by the following mathematical formula 1 is 11% to 15%. [Mathematical Formula 1] Primary particle factor = perimeter of primary particle (㎛) / average particle diameter of secondary particle (D 50 )(㎛) Х 100(%) The positive electrode active material precursor of the present invention is a positive electrode active material precursor that is a secondary particle formed by aggregating a plurality of primary particles, wherein the primary particles include particles having a polyhedral structure, and the particles having a polyhedral structure are included in an amount of 70% or more based on the total number of the primary particles. In the present invention, the term "polyhedron" means, in addition to the dictionary definition of "a three-dimensional figure surrounded by planar polygons and not on a plane," a shape that is distinguished from a sphere, a sphere-like shape, an elliptical sphere, an elliptical sphere-like shape, a sheet shape, etc. The above primary particle may have a surface or cross-section of a primary particle that is polygonal as observed from a SEM image (magnification: 20,000 times) of the surface of a positive electrode active material particle, and a side surrounding the polygon may include a straight line and a line having a constant curvature, and the polygon may be a plane having an interior angle of 2 or more. The above primary particle may have, for example, a crystalline particle, an n-hedron shape or an n-hedron-like shape (n is an integer of 5 or more), a shape having a constant volume with one plane and the rest being curved planes, a shape having a constant volume with two or more planes and the rest being curved planes, etc., and is not particularly limited thereto as long as it is not a sphere, a sphere-like shape, or a planar shape in which only the z-axis direction has an extremely small value compared to the x-axis and y-axis directions in a coordinate system, which is typically recognized as a sheet shape. The particles having the above polyhedral structure may be included in an amount of 70% or more, 75% or more, 80% or more, 85% or more, 90% or more, 95% or more, 99% or more, or 100% based on the total number of the primary particles. Since the positive electrode active material precursor of the present invention includes particles having a polyhedral structure in the above ratio among the plurality of primary particles, when the primary particles are aggregated to form secondary particles, the interior of the secondary particles may have a high density and exhibit a low specific surface area value. The positive electrode active material precursor of the present invention is a high-density positive electrode active material precursor having a high density inside the secondary particles, and also has a characteristic of having a low specific surface area compared to conventional positive electrode active material precursors. As such, the positive electrode active material precursor of the present invention having a high density inside the secondary particles and a low specific surface area can suppress lithium desorption during the firing process when manufacturing a positive electrode active material using the same, thereby reducing lithium remaining on the surface of the positive electrode active material and becoming an impurity, and can easily be formed into single particles even at a low firing temperature. The positive electrode active material precursor of the present invention has a plurality of primary particles densely assembled to form secondary particles, so it can include a small gap between the primary particles, and thus has a gap of 1.5 m 2 / g to 5.0 m 2 / g can exhibit a low BET specific surface area value. In one embodiment of the present invention, the BET specific surface area of ​​the positive electrode active material precursor is specifically 1.5 m 2 / g or more, 1.6 m 2 / g or more, 1.7 m 2 / g or more, 1.8 m 2 / g or more, 1.9 m 2 / g or more, 2.0 m 2 / g or more, 2.1 m 2 / g or more, 2.2 m 2 / g or more, 2.3 m 2 / g or more, 2.4 m 2 / g or more, 2.5 m 2 / g may be greater than or equal to 5.0 m 2 / g or less, 4.98 m 2 / g or less, 4.96 m 2 / g or less, 4.94 m 2 / g or less, 4.92 m 2 / g or less, 4.9 m 2 / g or less, 4.88 m 2 / g or less. When the positive electrode active material precursor satisfies the BET specific surface area range, the density of the positive electrode active material precursor corresponds to a density that can be easily formed into single particles during firing for manufacturing the positive electrode active material, so that single particles can be formed more effectively, and the effect of suppressing lithium desorption during firing of the positive electrode active material precursor can be exerted, so that the residual amount of lithium impurities can be reduced as much as possible. The above specific surface area is measured by the BET (Brunauer-Emmett-Teller) method, and specifically, can be calculated from the nitrogen gas adsorption amount at liquid nitrogen temperature (77 K) using Belsorp-mini II of Bel Japan Inc. In the positive electrode active material precursor according to one embodiment of the present invention, the primary particles may have a primary particle factor represented by the following mathematical formula 1 of 11% to 15%, specifically 11% or more, 11.05% or more, or 11.1% or more, 15% or less, 14.8% or less, 14.6% or less, 14.5% or less, 14.4% or less, 14.3% or less, 14.2% or less, or 14.1% or less. [Mathematical Formula 1] Primary particle factor = perimeter of primary particle (㎛) / average particle diameter of secondary particle (D 50 )(㎛) Х 100(%) The circumference of the primary particle can be obtained by obtaining an SEM image of the primary particle and segmenting the SEM image using a DX program to obtain the outermost outer circumference of the primary particle, i.e., the circumference length of the outermost surface of the primary particle. The above primary particle factor is the average particle diameter (D) of the secondary particle, which is the positive electrode active material precursor, divided by the circumference of the primary particle. 50) is expressed as a % value, and when the primary particle factor of the primary particle satisfies the above value, when manufacturing a positive electrode active material using a positive electrode active material precursor including the same, single particles can be more effectively achieved, and the amount of lithium remaining on the surface of the positive electrode active material can be reduced. When the primary particle factor is smaller than the above value, the number of pores inside the positive electrode active material precursor may increase and the specific surface area may increase. When the number of pores inside the positive electrode active material precursor increases, the sintering temperature must be further increased in order to manufacture a single-particle positive electrode active material, and thus, the residual lithium as an impurity may increase. On the other hand, when the primary particle factor is larger than the above value, the density inside the positive electrode active material precursor may increase and the specific surface area may decrease. When the density inside the positive electrode active material precursor becomes excessively high, the reactivity with Li may be reduced. In addition, the positive electrode active material precursor of the present invention can exhibit a higher level of tap density than the existing positive electrode active material precursor, 1.4 g / cm 3 2.6 g / cm 3 , specifically 1.5 g / cm 3 2.5 g / cm 3 , 1.6 g / cm 3 2.4 g / cm 3 , 1.7 g / cm 3 2.3 g / cm 3 , or 1.8 g / cm 3 2.2 g / cm 3 The tap density can be expressed. The tap density refers to the apparent density of the powder obtained by vibrating the container under certain conditions when filling the powder, and can be measured using a conventional tap density measuring device, and specifically, can be measured using Seishin's KYT-5000. In one embodiment of the present invention, the positive electrode active material precursor may contain nickel in an amount of 60 mol% or more among transition metals, and when the positive electrode active material is manufactured using the precursor, a high nickel-based single particle positive electrode active material containing nickel in an amount of 60 mol% or more among transition metals can be manufactured. In one embodiment of the present invention, the positive electrode active material precursor may be represented by the following chemical formula 1: [Chemical Formula 1] [Ni x Co y M 1 z M 2 w ](OH)2 In the above chemical formula 1, 0.6≤x<1, 0 <y<0.4, 0<z<0.4, 0≤w<0.4이고, M 1 is at least one selected from the group consisting of Mn and Al, and M 2 is at least one selected from the group consisting of Zr, B, Ce, V, Fe, Zn, Si, Ga, Sn, Hf, W, Mo, Cr, Nb, Mg, Hf, Ta, La, Ti, Sr, Ba, F, P, S and Y. When the positive electrode active material precursor is fired, a certain size (critical size, r) c ) or more of the positive electrode active material precursor particles are combined with each other to form a single particle, and have a certain size (critical size, r) c ) The positive electrode active material precursor particles having a particle size less than a certain size (r c ) are diffused and dissolved and moved by particles with a diameter of more than a certain size (r). c ) The bonding between particles above is more favorable for particle growth as temperature increases compared to time increases, and grain boundary formation is easy to occur. In addition, a certain size (r c ) smaller particles of a certain size (rc ) particles, the particles grow over time, which is advantageous for forming a single crystal. Therefore, when manufacturing a single-particle positive electrode active material by calcining a positive electrode active material precursor particle, a particle of a certain size (r) is required. c ) When bonding occurs between the particles above, a single-particle positive electrode active material can be manufactured more effectively. In this way, the positive electrode active material precursor according to one embodiment of the present invention has a span value [(D 90 -D 10 ) / D 50 ] can satisfy 0.4 to 0.8, specifically 0.45 to 0.75, and more specifically 0.5 to 0.7. Since the positive electrode active material precursor according to one embodiment of the present invention satisfies the span value of the above range, the positive electrode active material precursor particles exhibit a uniform particle size distribution and can effectively grow into a single particle while combining with each other. According to one embodiment of the present invention, the positive electrode active material precursor has a particle size D when the volume cumulative distribution standard becomes 10% 10 This may be 2.2 ㎛ to 4.2 ㎛, specifically 2.5 ㎛ to 4 ㎛, and more specifically 2.8 ㎛ to 3.8 ㎛. In addition, the positive electrode active material precursor according to one embodiment of the present invention has an average particle diameter (D 50 ) may be 3.0 ㎛ to 5.5 ㎛, specifically 3.5 ㎛ to 5 ㎛, and more specifically 4 ㎛ to 5 ㎛. In addition, the positive electrode active material precursor according to one embodiment of the present invention has a particle size D when the volume cumulative distribution standard becomes 90%. 90 This may be 4.8 ㎛ to 6.8 ㎛, specifically 5 ㎛ to 6.8 ㎛, and more specifically 5.5 ㎛ to 6.5 ㎛. According to one embodiment of the present invention, the positive electrode active material precursor comprises the D 10 , average particle diameter (D 50 ) and D 90 It may be satisfied, and when the positive electrode active material precursor according to one embodiment of the present invention satisfies the above average particle diameter ranges, the single particle of the positive electrode active material manufactured while the particles grow well during firing can be more effectively achieved. The positive electrode active material precursor of the present invention may be a spherical secondary particle. The spherical shape of the secondary particle is in contrast to the polygonal structure of the primary particle, and means a sphere or a sphere-like shape. For example, the 'spherical shape' may mean that the shape of the secondary particle observed in an SEM image (magnification: 2,000 times) of the surface of the positive electrode active material particle has a sphere or a sphere-like shape, and the shape of the surface or cross-section of the positive electrode active material particle may be circular or circular-like. The aspect ratio (major axis of the secondary particle / minor axis of the secondary particle) of the above-mentioned positive electrode active material precursor may be 1.3 or less, and more specifically, 1.3 or less, 1.29 or less, 1.25 or less, 1.2 or less, or 1.15 or less. The closer the aspect ratio is to 1, the closer the positive electrode active material precursor can exhibit a spherical shape. Meanwhile, the present invention provides a method for manufacturing the positive electrode active material precursor. The positive electrode active material precursor of the present invention can be manufactured by a method for manufacturing a positive electrode active material precursor, comprising: (A) a step of introducing a reaction solution including a transition metal-containing solution, an ammonium ion-containing solution, and a basic aqueous solution into a reactor having a filter installed therein; (B) a step of continuously introducing the transition metal-containing solution, the ammonium ion-containing solution, and the basic aqueous solution into the reactor while maintaining the pH of the reaction solution, thereby performing a positive electrode active material precursor particle growth reaction; and (C) a step of continuously performing the positive electrode active material precursor particle growth reaction while continuously discharging only the reaction waste solution to the outside of the reactor through a filter device inside the reactor when the reactor is full; In step (B), the ammonium ion-containing solution is introduced so that the molar ratio of the transition metal and the ammonium ion is 1:0.1 or more and 1.0 or less, and the basic aqueous solution is introduced so that the molar ratio of the transition metal and the hydroxide ion is 1:1.5 or more and 2.5 or less. In step (A), a reaction solution including a transition metal cation-containing solution, an ammonium ion-containing solution, and a basic aqueous solution is introduced into a reactor equipped with a filter device inside. The reaction solution can be introduced up to a certain volume of the reactor and adjusted to a pH at which the reaction is performed. The transition metals included in the above transition metal-containing solution are nickel, cobalt, M 1 (Here, M 1 It may be at least one selected from the group consisting of Mn and Al), and wherein nickel is at least 60 mol% of the transition metal. Specifically, the transition metal-containing solution may include acetate, nitrate, sulfate, halide, sulfide, hydroxide, oxide or oxyhydroxide of the transition metal, and as long as it can be dissolved in water, it may be used without particular limitation. For example, the nickel (Ni) may be included in the transition metal-containing solution as Ni(OH)2, NiO, NiOOH, NiCO3·2Ni(OH)2·4H2O, NiC2O2·2H2O, Ni(NO3)2·6H2O, NiSO4, NiSO4·6H2O, fatty acid nickel salt, or nickel halide, and at least one or more of these may be used. In addition, the cobalt (Co) may be included in the transition metal-containing solution as Co(OH)2, CoOOH, Co(OCOCH3)2ㆍ4H2O, Co(NO3)2ㆍ6H2O or CoSO4ㆍ7H2O, and at least one of these may be used. Also, the above M 1 In this case, the manganese (Mn) may be included in the transition metal-containing solution as manganese oxides such as Mn2O3, MnO2, and Mn3O4; manganese salts such as MnCO3, Mn(NO3)2, MnSO4, manganese acetate, manganese dicarboxylic acid salt, manganese citrate, and manganese fatty acid salt; oxyhydroxides, and manganese chloride, and at least one or more of these may be used. In addition, the above transition metal containing solution contains nickel, cobalt and M 1 In addition, other metallic elements (M 2 ) may further be included. At this time, the metal element M 2 It may include at least one selected from the group consisting of Zr, B, Ce, V, Fe, Zn, Si, Ga, Sn, Hf, W, Mo, Cr, Nb, Mg, Hf, Ta, La, Ti, Sr, Ba, F, P, S and Y. The above transition metal containing solution is a metal element M 2 When including more, the metal element M is used in the preparation of the transition metal-containing solution. 2 Additional raw materials may be added. The above metal element M 2 The raw material contained is the metal element M.2 At least one selected from the group consisting of acetate, nitrate, sulfate, halide, sulfide, hydroxide, oxide or oxyhydroxide may be used. For example, the metal element M 2 If W, tungsten oxide, etc. can be used. The above ammonium ion-containing solution may include at least one selected from the group consisting of NH4OH, (NH4)2SO4, NH4NO3, NH4Cl, CH3COONH4, and (NH4)2CO3. At this time, water or a mixture of water and an organic solvent (specifically, alcohol, etc.) that can be uniformly mixed with water may be used as the solvent. The above basic aqueous solution may include at least one selected from the group consisting of NaOH, KOH, and Ca(OH)2, and as a solvent, water or a mixture of water and an organic solvent (specifically, alcohol, etc.) that can be uniformly mixed with water may be used. In step (B), a transition metal-containing solution, an ammonium ion-containing solution, and a basic aqueous solution are continuously introduced into the reactor while maintaining the pH of the reaction solution, thereby performing a cathode active material precursor particle growth reaction. When a solution containing a transition metal is injected into a reactor and a coprecipitation reaction is performed to generate particle nuclei, the pH value of the reaction solution in the reactor changes according to the generation of particle nuclei. Therefore, the pH of the reaction solution is maintained by simultaneously injecting the solution containing a transition metal, the solution containing ammonium ions, and the basic aqueous solution into the reactor. The pH of the reaction solution of steps (A) and (B) may be 11 to 13, and specifically, may be 12 to 13. The positive electrode active material precursor particles may be manufactured by a method of generating precursor particles by performing a co-precipitation reaction under conditions of pH 11 to 13 within a reactor, and then controlling the particle size by maintaining the pH within the reactor as it was initially after generating the precursor particles. In one embodiment of the present invention, the transition metal-containing solution may be injected into the reactor so that the injection rate of the transition metal is 5 mol / hr to 30 mol / hr, specifically 6 mol / hr to 25 mol / hr, 7 mol / hr to 25 mol / hr, 6 mol / hr to 20 mol / hr, 7 mol / hr to 20 mol / hr, or 8 mol / hr to 20 mol / hr. If the injection rate of the transition metal is lower than the above range, the production amount of the positive electrode active material precursor may decrease, and if it exceeds the above range, the particle size distribution of the positive electrode active material precursor may not be uniform. In addition, the transition metal-containing solution injected into the reactor is injected so that the injection rate of the transition metal is within a constant range throughout the primary particle formation step and the secondary particle formation step, thereby causing particle growth to occur slowly at a constant rate. In the above step (B), the ammonium ion-containing solution is added so that the molar ratio of the transition metal and ammonium ion is 1:0.1 or more and 1.0 or less, and the basic aqueous solution is added so that the molar ratio of the transition metal and hydroxide ion is 1:1.5 or more and 2.5 or less. Here, the transition metal refers to the transition metal included in the transition metal-containing solution added in the above step (B), and the ammonium ion and the hydroxide ion are included in the ammonium ion-containing solution and the basic solution, respectively. Specifically, the ammonium ion-containing solution may be added so that the molar ratio of the transition metal and ammonium ion is 1:0.1 or more, 0.2 or more, 0.3 or more, 0.4 or more, or 0.6 or less, 0.7 or less, 0.8 or less, 0.9 or less, 1.0 or less. Specifically, the basic aqueous solution may be added so that the molar ratio of the transition metal and the hydroxide ion is 1:1.5 or more, 1.6 or more, 1.7 or more, 1.8 or more, 1.9 or more, or 2.1 or less, 2.2 or less, 2.3 or less, 2.4 or less, or 2.5 or less. When the ammonium ion-containing solution and the basic aqueous solution satisfy the molar ratio, a densely structured positive electrode active material precursor particle can be manufactured, and accordingly, a low specific surface area range of 1.5 m is achieved compared to a conventional positive electrode active material precursor. 2 / g to 5 m 2 A positive electrode active material precursor having a BET specific surface area of ​​ / g can be manufactured. In addition, since particle growth occurs at a constant rate throughout the reaction, the particle size and shape of the final positive electrode active material precursor can be manufactured uniformly. If the basic aqueous solution is added in excess of the above range, the density of the positive electrode precursor particles manufactured may decrease, the specific surface area may increase, and the uniformity of the particle shape may deteriorate. Meanwhile, in one example of the present invention, a precursor having a transition metal composition having a concentration gradient within a particle may be manufactured by using a first transition metal-containing solution containing nickel cations as the transition metal-containing solution and a second transition metal-containing solution having a different concentration of transition metal cations from the first transition metal-containing solution. For example, a first transition metal-containing solution and a second transition metal-containing solution having different concentrations of transition metal cations can be mixed using a mixer and then introduced into a reactor. The above first and second transition metal-containing solutions may include at least one cation selected from the group consisting of nickel, manganese, and cobalt, for example. The first and second transition metal-containing solutions may have different concentrations of each transition metal cation, and for example, the first transition metal-containing solution may be a solution having a higher concentration of nickel cations than the second transition metal-containing solution. For example, the first transition metal-containing solution may have a molar ratio of the nickel (Ni) salt of 80% or more with respect to the entire transition metal salt, and the second transition metal-containing solution may have a molar ratio of the nickel (Ni) salt of 60% or less with respect to the entire transition metal salt. In addition, the first transition metal-containing solution may be a solution having a lower concentration of at least one transition metal cation among manganese (Mn) and cobalt (Co) than the second transition metal solution. For example, the first transition metal-containing solution may have a molar ratio of the manganese (Mn) and / or cobalt (Co) salt of 20% or less with respect to the entire transition metal salt, and the second transition metal-containing solution may have a molar ratio of the manganese (Mn) and / or cobalt (Co) salt of 30% or more with respect to the entire transition metal salt. In this way, by controlling the injection speeds of the first transition metal-containing solution and the second transition metal-containing solution having different concentrations of transition metal cations, a precursor having a transition metal composition concentration gradient within the particle can be formed. For example, the injection speed of the first transition metal-containing solution may be gradually reduced, and the injection speed of the second transition metal-containing solution may be complementarily gradually increased to form a concentration gradient. In step (C), after a certain period of time, when the reactor is full, a portion of the reaction solution inside the reactor is continuously discharged to the outside of the reactor using a filter device, thereby continuously performing the cathode active material precursor particle growth reaction. In step (C), as in step (B), a transition metal-containing solution, an ammonium ion-containing solution, and a basic aqueous solution are continuously introduced into the reactor, and a cathode active material precursor particle growth reaction is continuously performed, causing the particles to grow. The above reactor being full means that the volume of the injected reaction solutions occupies 90% to 100% of the total volume of the reactor. Specifically, by continuously discharging only the completed reaction solution outside the reactor using a filter device inside the reactor while simultaneously introducing a transition metal-containing solution, an ammonium ion-containing solution, and a basic aqueous solution into the reactor, the positive electrode active material precursor particles can be further grown. As the above-described positive electrode active material precursor particles grow, the solid concentration within the reactor increases at a constant rate, and as the solid concentration within the reactor increases, the growth rate of the positive electrode active material precursor particles slows down, thereby producing positive electrode active material precursor particles having a narrow particle size distribution and a dense structure. In addition, when the reaction solution in which the reaction is completed is discharged outside the reactor and the reaction solution is simultaneously introduced into the reactor, more particle growth can occur during the same reaction time, thereby significantly increasing the productivity of the precursor particles. The discharge flow rate of the reaction solution may be the same as the input flow rate of the reaction solution. For example, if the input flow rate of the reaction solution is faster than the output flow rate of the reaction solution, the water level in the reactor may increase, making continuous reaction impossible. If the input flow rate of the reaction solution is slower than the output flow rate of the reaction solution, the water level in the reactor may decrease, making continuous reaction impossible. The discharge of the above reaction solution may be such that only the reaction solution is discharged outside the reactor using a filtering device, and the positive electrode active material precursor particles are not discharged outside the reactor by the filtering device, and only the reaction solution is selectively and continuously discharged outside the reactor. At this time, the filtering device may include a filter made of a metal material, and specifically, may include at least one selected from the group consisting of stainless steel and carbon steel. The filter made of the metal material may include pores, and the size of the pores may be smaller than the size of the positive electrode active material precursor. When using a metal filter as described above, the flow rate per unit area passing through the filter device is high, allowing the reaction solution inside the reactor to be continuously discharged outside the reactor within a short period of time. Accordingly, the reaction solution can be discharged outside the reactor and simultaneously introduced into the reactor. For example, when a non-woven filter material is used as the above-mentioned filter device, the flow rate of the solution passing through the non-woven filter material is very small, so the discharge of the reaction solution and the introduction of the reaction solution cannot be performed simultaneously. In addition, the filtering device may be a pleated filter, in which case the specific surface area of ​​the filtering device increases, so that the filtration flow rate per unit area can be increased by more than five times compared to a case where the same flow rate of solution per unit area is injected into a simple filtering device of the same size. In addition, the method for manufacturing a positive electrode active material precursor according to one embodiment of the present invention can manufacture positive electrode active material precursor particles having a dense structure with a higher density by appropriately controlling the pH inside the reactor at each step as described above, so that only the generation of primary particles occurs in a relatively high pH range, and only the growth of the primary particles and the aggregation during the growth process of the primary particles occur in a relatively low pH range, thereby producing positive electrode active material precursor particles having a dense structure with a higher density, and thus, compared to conventional positive electrode active material precursors, the specific surface area range is lower than 1.5 m. 2 / g to 5 m 2 A positive electrode active material precursor having a BET specific surface area of ​​ / g can be manufactured. In addition, particle growth occurs at a constant rate throughout the reaction, so that the particle size and shape of the final positive electrode active material precursor can be manufactured uniformly. Meanwhile, in the manufacturing method of the present invention, the solid concentration in the reactor may increase at a constant rate, for example, 0.5 to 4.5% per hour, specifically 0.5 to 4%, 0.5 to 3.5%, 1 to 4.5%, 1 to 4%, 1 to 3.5%, or 1% to 3%. In addition, it is preferable that the manufacturing of the positive electrode active material precursor is continuously reacted for 2 to 15 days after the start of the reaction, and the reaction is terminated when the solid concentration in the reactor becomes 20 to 140%, preferably 80 to 120%. In this way, when the solid concentration within the reactor is increased at a constant rate and the reaction is terminated when the solid concentration within the reactor reaches 20% to 140%, the productivity of the precursor particles increases, and at the same time, positive electrode active material precursor particles having a narrow particle size distribution and a dense structure can be produced. Specifically, when the positive electrode active material precursor particles manufactured according to the present invention are manufactured, the precursor production amount is significantly increased compared to when the positive electrode active material precursor is manufactured using a conventional method without discharging or additionally adding the reaction solution using a batch reactor of the same size. In one embodiment of the present invention, the method for manufacturing the positive electrode active material can be performed using a reactor as illustrated in FIG. 1. A positive electrode active material precursor manufactured by the above manufacturing method can be mixed with a lithium-containing raw material and calcined to manufacture a positive electrode active material. The above lithium-containing raw material is not particularly limited as long as it is a compound containing a lithium source, but preferably, at least one selected from the group consisting of lithium carbonate (Li2CO3), lithium hydroxide (LiOH), LiNO3, CH3COOLi, and Li2(COO)2 can be used. The above positive electrode active material precursor and lithium-containing raw material may be mixed in a molar ratio of 1:1 to 1:1.15. If the lithium-containing raw material is mixed in an amount less than the above range, there is a concern that the capacity of the positive electrode active material produced may be reduced. If the lithium-containing raw material is mixed in an amount exceeding the above range, the particles may be sintered during the firing process, making it difficult to produce the positive electrode active material. In addition, a decrease in capacity and separation of positive electrode active material particles after firing (causing a positive electrode active material impregnation phenomenon) may occur. The above sintering can be performed at a temperature of 700°C to 1000°C. If the sintering temperature is lower than 700°C, the raw material may remain in the particles due to insufficient reaction, which may lower the high-temperature stability of the battery, and the bulk density and crystallinity may decrease, which may lower the structural stability. On the other hand, if the sintering temperature exceeds 1000°C, the particles may grow unevenly, and the particle size may become too large, reducing the amount of particles that can be contained per unit area, which may lower the volumetric capacity of the battery. On the other hand, when considering the particle size control, capacity, stability, and reduction of lithium-containing byproducts of the manufactured positive electrode active material, the sintering temperature may be more preferably 700°C to 950°C. The above calcination can be performed for 5 to 35 hours. If the calcination time is less than 5 hours, the reaction time may be too short, making it difficult to obtain a highly crystalline positive electrode active material. If the calcination time exceeds 35 hours, the particle size may become excessively large, and production efficiency may decrease. In addition, the present invention provides a positive electrode for a lithium secondary battery comprising a positive electrode active material manufactured by the above-described method. Specifically, the positive electrode for the secondary battery includes a positive electrode current collector and a positive electrode active material layer formed on the positive electrode current collector, and the positive electrode active material layer includes a positive electrode active material according to the present invention. At this time, since the positive electrode active material is the same as described above, a detailed description is omitted, and only the remaining components are specifically described below. The positive electrode current collector is not particularly limited as long as it is conductive and does not cause a chemical change in the battery, and for example, stainless steel, aluminum, nickel, titanium, calcined carbon, or aluminum or stainless steel surface-treated with carbon, nickel, titanium, silver, etc. may be used. In addition, the positive electrode current collector may typically have a thickness of 3 to 500 μm, and fine unevenness may be formed on the surface of the positive electrode current collector to increase the adhesive strength of the positive electrode active material. For example, the positive electrode current collector may be used in various forms such as a film, sheet, foil, net, porous body, foam, or non-woven fabric. The above positive electrode active material layer may include a conductive material and optionally a binder, together with the positive electrode active material. At this time, the positive electrode active material may be included in an amount of 80 to 99 wt%, more specifically 85 to 98.5 wt%, based on the total weight of the positive electrode active material layer. When included in the above content range, excellent capacity characteristics can be exhibited. The conductive material is used to provide conductivity to the electrode, and in the battery to be formed, as long as it does not cause a chemical change and has electronic conductivity, it can be used without any special restrictions. Specific examples include graphite such as natural graphite or artificial graphite; carbon-based materials such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, summer black, and carbon fiber; metal powder or metal fiber such as copper, nickel, aluminum, and silver; conductive whiskers such as zinc oxide or potassium titanate; conductive metal oxides such as titanium oxide; or conductive polymers such as polyphenylene derivatives, and the like. One of these may be used alone or a mixture of two or more may be used. The conductive material may be included in an amount of 0.1 to 15 wt% based on the total weight of the positive electrode active material layer. The binder improves adhesion between positive electrode active material particles and adhesion between the positive electrode active material and the current collector. Specific examples thereof include polyvinylidene fluoride (PVDF), vinylidene fluoride-hexafluoropropylene copolymer (PVDF-co-HFP), polyvinyl alcohol, polyacrylonitrile, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene polymer (EPDM), sulfonated-EPDM, styrene butadiene rubber (SBR), fluoroelastomer, or various copolymers thereof, and one of these may be used alone or a mixture of two or more thereof. The binder may be included in an amount of 0.1 to 15 wt% based on the total weight of the positive electrode active material layer. The above-mentioned positive electrode can be manufactured according to a conventional positive electrode manufacturing method, except that the above-mentioned positive electrode active material is used. Specifically, the positive electrode active material layer forming composition, which is manufactured by dissolving or dispersing the above-mentioned positive electrode active material and optionally a binder and a conductive agent in a solvent, is applied onto a positive electrode current collector, followed by drying and rolling. The solvent may be a solvent generally used in the relevant technical field, such as dimethyl sulfoxide (DMSO), isopropyl alcohol, N-methylpyrrolidone (NMP), acetone, or water. One of these may be used alone or a mixture of two or more thereof may be used. The amount of the solvent used is sufficient to dissolve or disperse the positive electrode active material, conductive material, and binder, taking into account the coating thickness and manufacturing yield of the slurry, and to have a viscosity that can exhibit excellent thickness uniformity when applied thereafter for manufacturing the positive electrode. Additionally, in another method, the positive electrode may be manufactured by casting the composition for forming the positive electrode active material layer on a separate support, and then laminating the resulting film on a positive electrode current collector by peeling it off from the support. In addition, the present invention can manufacture an electrochemical device including the positive electrode. The electrochemical device may be a battery, a capacitor, or the like, and more specifically, a lithium secondary battery. The lithium secondary battery specifically includes a positive electrode, a negative electrode positioned opposite the positive electrode, and a separator and electrolyte interposed between the positive electrode and the negative electrode. Since the positive electrode is the same as described above, a detailed description thereof will be omitted, and only the remaining components will be described in detail below. In addition, the lithium secondary battery may optionally further include a battery container that houses the electrode assembly of the positive electrode, the negative electrode, and the separator, and a sealing member that seals the battery container. In the above lithium secondary battery, the negative electrode includes a negative electrode current collector and a negative electrode active material layer positioned on the negative electrode current collector. The negative electrode current collector is not particularly limited as long as it has high conductivity without causing chemical changes in the battery, and for example, copper, stainless steel, aluminum, nickel, titanium, calcined carbon, copper or stainless steel surface-treated with carbon, nickel, titanium, silver, etc., aluminum-cadmium alloy, etc. can be used. In addition, the negative electrode current collector can typically have a thickness of 3 ㎛ to 500 ㎛, and like the positive electrode current collector, fine unevenness can be formed on the surface of the current collector to strengthen the bonding strength of the negative electrode active material. For example, it can be used in various forms such as a film, a sheet, a foil, a net, a porous body, a foam, a non-woven fabric, etc. The above negative electrode active material layer optionally includes a binder and a conductive material together with the negative electrode active material. As the negative electrode active material, a compound capable of reversible intercalation and deintercalation of lithium may be used. Specific examples include carbonaceous materials such as artificial graphite, natural graphite, graphitized carbon fiber, and amorphous carbon; metallic compounds capable of alloying with lithium such as Si, Al, Sn, Pb, Zn, Bi, In, Mg, Ga, Cd, Si alloy, Sn alloy, or Al alloy; SiO β(0<β<2), SnO2, vanadium oxide, lithium vanadium oxide, and other metal oxides capable of doping and dedoping lithium; or composites containing the above metallic compounds and carbonaceous materials, such as Si-C composites or Sn-C composites, and any one or a mixture of two or more of these may be used. In addition, a metallic lithium thin film may be used as the negative electrode active material. In addition, both low-crystalline carbon and high-crystalline carbon may be used as the carbonaceous material. Representative examples of low-crystalline carbon include soft carbon and hard carbon, and representative examples of high-crystalline carbon include natural graphite or artificial graphite in the form of amorphous, plate-like, flaky, spherical, or fiber-like forms, Kish graphite, pyrolytic carbon, mesophase pitch-based carbon fiber, meso-carbon microbeads, mesophase pitches, and high-temperature calcined carbon such as petroleum or coal tar pitch derived cokes. The above negative electrode active material may be included in an amount of 80 wt% to 99 wt% based on the total weight of the negative electrode active material layer. The above binder is a component that assists in bonding between the conductive material, the active material, and the current collector, and is typically added in an amount of 0.1 wt% to 10 wt% based on the total weight of the negative electrode active material layer. Examples of such binders include polyvinylidene fluoride (PVDF), polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinyl pyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene polymer (EPDM), sulfonated-EPDM, styrene-butadiene rubber, nitrile-butadiene rubber, fluororubber, and various copolymers thereof. The conductive agent is a component for further improving the conductivity of the negative electrode active material, and may be added in an amount of 10 wt% or less, preferably 5 wt% or less, based on the total weight of the negative electrode active material layer. The conductive agent is not particularly limited as long as it has conductivity and does not cause a chemical change in the battery, and examples thereof include graphite such as natural graphite or artificial graphite; carbon black such as acetylene black, Ketjen black, channel black, furnace black, lamp black, and thermal black; conductive fibers such as carbon fiber or metal fiber; metal powders such as fluorocarbon, aluminum, and nickel powder; conductive whiskers such as zinc oxide or potassium titanate; conductive metal oxides such as titanium oxide; and conductive materials such as polyphenylene derivatives. For example, the negative electrode active material layer can be manufactured by applying and drying a composition for forming a negative electrode active material layer prepared by dissolving or dispersing a negative electrode active material, and optionally a binder and a conductive material in a solvent, on a negative electrode current collector, or by casting the composition for forming a negative electrode active material layer on a separate support, and then laminating the film obtained by peeling it off from the support on a negative electrode current collector. The negative electrode active material layer may be manufactured by, for example, applying a composition for forming a negative electrode active material layer prepared by dissolving or dispersing a negative electrode active material, and optionally a binder and a conductive material in a solvent, onto a negative electrode current collector and drying the composition, or by casting the composition for forming a negative electrode active material layer onto a separate support and then laminating the film obtained by peeling it off from the support onto a negative electrode current collector. Meanwhile, in the lithium secondary battery, the separator separates the negative electrode and the positive electrode and provides a passage for lithium ions to move. Any separator commonly used in lithium secondary batteries can be used without special restrictions, and in particular, one having low resistance to ion movement of the electrolyte and excellent electrolyte moisture absorption capacity is preferable. Specifically, a porous polymer film, for example, a porous polymer film made of a polyolefin polymer such as an ethylene homopolymer, a propylene homopolymer, an ethylene / butene copolymer, an ethylene / hexene copolymer, and an ethylene / methacrylate copolymer, or a laminated structure of two or more layers thereof, may be used. In addition, a conventional porous nonwoven fabric, for example, a nonwoven fabric made of high-melting-point glass fiber, polyethylene terephthalate fiber, etc. may be used. In addition, a coated separator containing a ceramic component or a polymer material to secure heat resistance or mechanical strength may be used, and may optionally be used in a single-layer or multi-layer structure. In addition, examples of the electrolyte used in the present invention include, but are not limited to, organic liquid electrolytes, inorganic liquid electrolytes, solid polymer electrolytes, gel-type polymer electrolytes, solid inorganic electrolytes, and molten inorganic electrolytes that can be used in the manufacture of lithium secondary batteries. Specifically, the electrolyte may include an organic solvent and a lithium salt. As the organic solvent, any solvent that can serve as a medium through which ions involved in the electrochemical reaction of the battery can move may be used without particular limitation. Specifically, the organic solvent includes ester solvents such as methyl acetate, ethyl acetate, γ-butyrolactone, and ε-caprolactone; ether solvents such as dibutyl ether or tetrahydrofuran; ketone solvents such as cyclohexanone; aromatic hydrocarbon solvents such as benzene and fluorobenzene; carbonate solvents such as dimethylcarbonate (DMC), diethylcarbonate (DEC), ethylmethylcarbonate (EMC), ethylene carbonate (EC), and propylene carbonate (PC); Alcohol solvents such as ethyl alcohol, isopropyl alcohol, etc.; nitriles such as R-CN (R is a linear, branched, or cyclic hydrocarbon group having 2 to 20 carbon atoms and may include a double-bonded aromatic ring or an ether bond); amides such as dimethylformamide; dioxolanes such as 1,3-dioxolane; or sulfolanes, etc. can be used. Among these, carbonate solvents are preferable, and a mixture of a cyclic carbonate (e.g., ethylene carbonate or propylene carbonate) having high ionic conductivity and high dielectric constant that can improve the charge / discharge performance of a battery and a low-viscosity linear carbonate compound (e.g., ethyl methyl carbonate, dimethyl carbonate, or diethyl carbonate) is more preferable.In this case, the performance of the electrolyte may be improved when the cyclic carbonate and the chain carbonate are mixed and used in a volume ratio of about 1:1 to about 1:9. The above lithium salt can be used without any special limitation as long as it is a compound that can provide lithium ions used in a lithium secondary battery. Specifically, the above lithium salt is LiPF6, LiClO4, LiAsF6, LiBF4, LiSbF6, LiAl04, LiAlCl4, LiCF3SO3, LiC4F9SO3, LiN(C2F5SO3)2, LiN(C2F5SO2)2, LiN(CF3SO2) 2. LiCl, LiI, or LiB(C2O4)2 can be used. It is recommended that the concentration of the lithium salt be within the range of 0.1 to 2.0 M. When the concentration of the lithium salt is within the above range, the electrolyte can exhibit excellent electrolyte performance because it has appropriate conductivity and viscosity, and lithium ions can move effectively. In addition to the electrolyte components, the electrolyte may further include one or more additives, such as haloalkylene carbonate compounds such as difluoroethylene carbonate, pyridine, triethylphosphite, triethanolamine, cyclic ethers, ethylene diamine, n-glyme, hexaphosphoric acid triamide, nitrobenzene derivatives, sulfur, quinone imine dyes, N-substituted oxazolidinones, N,N-substituted imidazolidines, ethylene glycol dialkyl ethers, ammonium salts, pyrrole, 2-methoxyethanol, or aluminum trichloride, for the purpose of improving the life characteristics of the battery, suppressing battery capacity decrease, and improving the discharge capacity of the battery. At this time, the additives may be included in an amount of 0.1 to 5 wt% based on the total weight of the electrolyte. As described above, a lithium secondary battery including a cathode active material according to the present invention stably exhibits excellent discharge capacity, output characteristics, and lifespan characteristics, and is therefore useful in portable devices such as mobile phones, laptop computers, and digital cameras, and electric vehicles such as hybrid electric vehicles (HEVs). Accordingly, according to another embodiment of the present invention, a battery module including the lithium secondary battery as a unit cell and a battery pack including the same are provided. The above battery module or battery pack can be used as a power source for one or more medium- to large-sized devices, such as a power tool; an electric vehicle (EV), a hybrid electric vehicle, and a plug-in hybrid electric vehicle (PHEV); or a power storage system. There is no particular limitation on the external shape of the lithium secondary battery of the present invention, but it may be a cylindrical shape using a can, a square shape, a pouch shape, or a coin shape. The lithium secondary battery according to the present invention can be used not only as a battery cell used as a power source for a small device, but can also be preferably used as a unit battery in a medium- to large-sized battery module including a plurality of battery cells. Hereinafter, the present invention will be described in detail with reference to examples. However, the examples according to the present invention may be modified in various ways, and the scope of the present invention should not be construed as being limited to the examples described below. The examples of the present invention are provided to more fully explain the present invention to those of ordinary skill in the art. Example Example 1 A 2.4 M transition metal solution was prepared by mixing NiSO4, CoSO4, and MnSO4 in deionized water in an amount such that the molar ratio of nickel:cobalt:manganese was 89:3:8. After adding 0.15 L of a 7.92 M NaOH aqueous solution, 1.15 L of a 5.08 M NH4OH aqueous solution, and 28.7 L of deionized water to the reactor, nitrogen gas was purged into the reactor at a rate of 20 L / min to remove dissolved oxygen. The stirring speed was 600 rpm, the reaction temperature was 60°C, and the pH in the reactor was maintained at 12.4 to 12.5. Afterwards, the transition metal-containing solution was fed into the reactor at a rate of 8.7 mol / h, the NaOH aqueous solution at 17 to 18 mol / h, and the NH4OH aqueous solution at 4.4 mol / h, respectively, while maintaining the pH at 12.4 to 12.5. The reactor (80 L) was full after 7 hours, and only the reaction waste solution was continuously discharged outside the reactor through a filter device inside the reactor. The reaction was carried out for a total of 96 hours, and the resulting precursor was separated, washed with water, and dried in an oven at 120°C for 15 hours to obtain D 50 A precursor of 4.5 μm was prepared. Example 2 A 2.4 M transition metal solution was prepared by mixing NiSO4, CoSO4, and MnSO4 in deionized water in an amount such that the molar ratio of nickel:cobalt:manganese was 89:3:8. After adding 0.15 L of a 7.92 M NaOH aqueous solution, 1.15 L of a 5.08 M NH4OH aqueous solution, and 28.7 L of deionized water to the reactor, nitrogen gas was purged into the reactor at a rate of 20 L / min to remove dissolved oxygen. The stirring speed was 600 rpm, the reaction temperature was 50°C, and the pH in the reactor was maintained at 12.4 to 12.5. Afterwards, the transition metal-containing solution was fed into the reactor at a rate of 17.4 mol / h, the NaOH aqueous solution at 34 to 35 mol / h, and the NH4OH aqueous solution at 8.7 mol / h, respectively, while maintaining the pH at 12.4 to 12.5. The reactor (80 L) was full after 3.5 hours, and only the reaction waste solution was continuously discharged outside the reactor through a filter device inside the reactor. The reaction was carried out for a total of 32 hours, and the resulting precursor was separated, washed with water, and dried in an oven at 120°C for 15 hours to obtain D 50 A precursor of 4.6 μm was prepared. Comparative Example 1 A 2.4 M transition metal solution was prepared by mixing NiSO4, CoSO4, and MnSO4 in deionized water in an amount such that the molar ratio of nickel:cobalt:manganese was 89:3:8. After adding 0.17 L of a 7.92 M NaOH aqueous solution, 0.85 L of a 5.08 M NH4OH aqueous solution, and 28.98 L of deionized water to the reactor, nitrogen gas was purged into the reactor at a rate of 20 L / min to remove dissolved oxygen. The stirring speed was 600 rpm, the reaction temperature was 50°C, and the pH in the reactor was maintained at 12.4 to 12.5. Afterwards, the transition metal-containing solution was fed into the reactor at a rate of 17.9 mol / h, the NaOH aqueous solution at 35 to 36 mol / h, and the NH4OH aqueous solution at 7.2 mol / h, respectively, to maintain the pH at 12.4 to 12.5. The reactor (80 L) was filled with the solution after 3.5 hours, and only the reaction waste solution was continuously discharged outside the reactor through a filter device inside the reactor. The reaction was carried out for a total of 40 hours, and the resulting precursor was separated, washed with water, and dried in an oven at 120°C for 15 hours to obtain D 50 A precursor of 4.6 μm was prepared. Comparative Example 2 A 2.4 M transition metal solution was prepared by mixing NiSO4, CoSO4, and MnSO4 in deionized water in an amount such that the molar ratio of nickel:cobalt:manganese was 89:3:8. After adding 0.15 L of a 7.92 M NaOH aqueous solution, 1.15 L of a 5.08 M NH4OH aqueous solution, and 28.7 L of deionized water to the reactor, nitrogen gas was purged into the reactor at a rate of 20 L / min to remove dissolved oxygen. The stirring speed was 600 rpm, the reaction temperature was 50°C, and the pH in the reactor was maintained at 12.4 to 12.5. Afterwards, the transition metal-containing solution was fed into the reactor at a rate of 17.6 mol / h, the NaOH aqueous solution at 35 to 36 mol / h, and the NH4OH aqueous solution at 7.2 mol / h, respectively, to maintain the pH at 12.4 to 12.5. The reactor (80 L) was filled with the solution after 3.5 hours, and only the reaction waste solution was continuously discharged outside the reactor through a filter device inside the reactor. The reaction was carried out for a total of 33 hours, and the resulting precursor was separated, washed with water, and dried in an oven at 120°C for 15 hours to obtain D 50 A precursor of 4.2 μm was prepared. Comparative Example 3 A 2.4 M transition metal solution was prepared by mixing NiSO4, CoSO4, and MnSO4 in deionized water in an amount such that the molar ratio of nickel:cobalt:manganese was 89:3:8. After adding 0.15 L of a 7.92 M NaOH aqueous solution, 1.33 L of a 5.08 M NH4OH aqueous solution, and 28.52 L of deionized water to the reactor, nitrogen gas was purged into the reactor at a rate of 20 L / min to remove dissolved oxygen. The stirring speed was 600 rpm, the reaction temperature was 40°C, and the pH in the reactor was maintained at 12.4 to 12.5. Afterwards, the transition metal-containing solution was fed into the reactor at a rate of 18.36 mol / h, the NaOH aqueous solution at 35 to 37 mol / h, and the NH4OH aqueous solution at 5.5 mol / h, respectively, to maintain the pH at 11.6. The reactor (80 L) was filled with the solution after 3.5 hours, and only the reaction waste solution was continuously discharged outside the reactor through a filter device inside the reactor. The reaction was carried out for a total of 20 hours, and the resulting precursor was separated, washed with water, and dried in an oven at 120°C for 15 hours to obtain D 50 A precursor of 3.2 μm was prepared. Experimental Example 1: Evaluation of the morphology and particle size distribution of precursor particles The SEM images of the positive electrode active material precursors manufactured in Example 1 and Comparative Examples 1 and 2 are shown in FIGS. 2 to 4, respectively. In addition, in order to confirm the particle size distribution of the positive electrode active material precursor particles, the particle sizes of the positive electrode active material precursors manufactured in Examples 1 and 2 and Comparative Examples 1 to 3 were measured using Microtrac's S-3500, and the results are shown in Table 1 below. In addition, the aspect ratio (major axis of the secondary particle / minor axis of the secondary particle) of each positive electrode active material precursor was calculated and shown together in Table 1 below. D 50 (㎛)(D 90 -D 10 ) / D 50 D 10 (㎛)D 90 (㎛) Aspect ratio Example 14.5 0.5 9 3.25 9 1.14 Example 24.6 0.6 0 3.5 6.3 1.29 Comparative example 14.6 0.6 0 3.4 6.2 1.28 Comparative example 24.20 6 5 3.15 8 1.32 Comparative example 33.20 7 7 2.0 4.4 1.30 Referring to the left drawing of Fig. 2, it can be confirmed that the positive electrode active material precursor manufactured in Example 1 is a secondary particle of a spherical structure formed by the aggregation of primary particles of a polyhedral structure, and also referring to the right drawing, it can be confirmed that the sizes of each particle are similar without any particles being too small or too large. On the other hand, referring to the left drawing of FIG. 3, it can be confirmed that the positive electrode active material precursor manufactured in Comparative Example 1 is a secondary particle formed by aggregating primary particles in the shape of sheets, slices, or petals, and referring to the right drawing, it can be confirmed that significantly small particles and large particles formed by aggregating multiple particles are mixed, so that the uniformity of particle size is lower than that of Example 1, and that secondary particles whose outer shell shape deviates from a sphere and forms a polygon are included. In addition, referring to the left drawing of FIG. 4, it can be confirmed that the positive electrode active material manufactured in Comparative Example 2 is a secondary particle having a spherical structure formed by aggregating primary particles with a gentle outer shell structure, and referring to the right drawing, as in Comparative Example 1, it can be confirmed that significantly small particles and large particles formed by aggregating multiple particles are mixed, so that the uniformity of particle size is lower than that of Example 1, and that secondary particles whose outer shell shape deviates from a sphere and forms a polygon are included in a larger amount than that of Comparative Example 1. When comparing the aspect ratios of the positive electrode active material precursors manufactured in Examples 1 and 2 and Comparative Examples 1 to 3, the aspect ratios of the positive electrode active material precursors of Examples 1 and 2 are equal to or smaller than the aspect ratios of the positive electrode active material precursors of Comparative Examples 1 to 3, and show values ​​closer to 1, so it can be confirmed numerically that the positive electrode active material precursors of the examples are close to a spherical structure. In addition, as can be confirmed numerically in Table 1 above, it was confirmed that the positive electrode active material precursors of Examples 1 and 2 had a more uniform particle size compared to Comparative Examples 1 to 3. Experimental Example 2: Tap Density Evaluation Using a particle density meter (Seishin Corporation), 50 g of the positive electrode active material precursor particles manufactured in Examples 1 and 2 and Comparative Examples 1 to 3 were filled into a dedicated flask, and the final volume obtained by vibrating the flask up and down 3,000 times was measured to measure the apparent density. Experimental Example 3: Surface Area Evaluation The surface area of ​​3.5 g of the positive electrode active material precursor particles manufactured in Examples 1 and 2 and Comparative Examples 1 to 3 was measured using a BET 6-point method by nitrogen gas adsorption flow using a specific surface area analyzer (tristar, manufactured by Micromeritics). Tap density (g / cc) Specific surface area (m 2 / g) Example 12.002.59 Example 21.904.86 Comparative Example 12.018.16 Comparative Example 21.909.48 Comparative Example 31.736.37 As shown in Table 2 above, the positive electrode active material precursors of Examples 1 and 2 exhibited high tap density, and it was confirmed that the specific surface area was significantly smaller than that of the positive electrode active material precursors of Comparative Examples 1 to 3. Experimental Example 4: Measurement of Primary Particle Factor After taking SEM images of the positive electrode active material precursors manufactured in Examples 1 and 2 and Comparative Examples 1 to 3, the average particle diameter (D) of the positive electrode active material precursors was measured using a DX program. 50 ) and the perimeter (outermost perimeter) of the primary particles were obtained. Figure 5 shows a segmentation image of the primary particles obtained using the SEM image of the lithium transition metal oxide manufactured using the positive electrode active material precursor manufactured in Example 1. Using this, the first particle factor was calculated using the following mathematical formula 1. [Mathematical Formula 1] Primary particle factor = perimeter of primary particle (㎛) / average particle diameter of secondary particle (D 50 )(㎛) Х 100(%) Primary particle circumference (㎛) Average particle diameter (D) 50 ) (㎛) Primary particle factor Example 10.6 3 4.5 14.07 Example 20.5 2 4.6 11.11 Comparative example 10.5 0 4.6 10.80 Comparative example 20.4 1 4.2 9.83 Comparative example 30.3 7 3.2 11.82 Experimental Example 5: Single-Particle Evaluation The positive electrode active material precursors manufactured in Example 1 and Comparative Examples 1 and 2 and LiOH were mixed in a molar ratio of 1:1.05, and calcined at a temperature of 860°C for 12 hours in an oxygen atmosphere to manufacture each lithium transition metal oxide. SEM images of lithium transition metal oxides manufactured using the positive electrode active material precursors manufactured in Example 1 and Comparative Examples 1 and 2 are shown in FIGS. 6 to 8, respectively. Referring to Fig. 6, it can be confirmed that the cathode active material precursor manufactured in Example 1 is easily single-particleized, and thus single-particleization is well achieved when manufacturing a lithium transition metal oxide using it. In comparison, as can be seen in Fig. 7, when a lithium transition metal oxide was manufactured using the positive electrode active material precursor manufactured in Comparative Example 1, single particle formation was not achieved well, so that small-diameter particles that were not single particles remained, and multiple particles remained in an agglomerated state. In addition, referring to Fig. 8, when a lithium transition metal oxide was manufactured using the positive electrode active material precursor manufactured in Comparative Example 2, multiple particles were agglomerated together to form a large secondary particle or secondary structure. Experimental Example 6: Measurement of Residual Lithium Amount in Manufactured Positive Electrode Active Material For each lithium transition metal oxide manufactured in the above Experimental Example 5, the content of lithium byproduct was measured using the Warder titration method of titrating the amount of CO3 ions and the amount of OH ions using an 888 titrando device from Mettler Toledo, and the results are shown in Table 4 below. Li2CO3(wt%)LiOH(wt%)Total Li byproduct(wt%)Example 10.110.090.20Comparative Example 10.150.120.27Comparative Example 20.230.140.37 It was confirmed that the lithium transition metal oxide manufactured using the positive electrode active material precursor of Example 1 had a significantly lower content of lithium impurities, Li2CO3 and LiOH, compared to Comparative Examples 1 and 2.

Claims

1. A positive electrode active material precursor that is a secondary particle formed by the aggregation of multiple primary particles. The above primary particles include particles having a polyhedral structure, The above secondary particles are particles with a spherical structure, A positive electrode active material precursor having a primary particle factor of 11% to 15%, as expressed by the following mathematical formula 1. [Mathematical Formula 1] Primary particle factor = perimeter of primary particle (㎛) / average particle diameter of secondary particle (D 50 )(㎛) Х 100(%) 2. In paragraph 1, The BET specific surface area of ​​the above positive electrode active material precursor is 1.5 m 2 / g to 5.0 m 2 / g positive electrode active material precursor.

3. In paragraph 1, The tap density of the above positive electrode active material precursor is 1.4 g / cm 3 2.6 g / cm 3 A precursor for positive electrode active material.

4. In paragraph 1, The span value of the above positive electrode active material precursor [(D 90 -D 10 ) / D 50 ] is a positive electrode active material precursor having a value of 0.4 to 0.

8.

5. In paragraph 1, The above positive electrode active material precursor is D 10 A positive electrode active material precursor having a diameter of 2.2 μm to 4.2 μm.

6. In paragraph 1, The above positive electrode active material precursor has an average particle diameter (D 50 ) is a positive electrode active material precursor having a diameter of 3.0 ㎛ to 5.5 ㎛.

7. In paragraph 1, The above positive electrode active material precursor is D 90 A positive electrode active material precursor having a diameter of 4.8 μm to 6.8 μm.

8. In paragraph 1, The above positive electrode active material precursor is a positive electrode active material precursor containing 60 mol% or more of nickel among transition metals.

9. In paragraph 1, The above positive electrode active material precursor is a positive electrode active material precursor represented by the following chemical formula 1: [Chemical Formula 1] [Ni x Co y M 1 z M 2 w ](OH)2 In the above chemical formula 1, 0.6≤x<1, 0 <y<0.4, 0<z<0.4, 0≤w<0.4이고, M 1 is at least one selected from the group consisting of Mn and Al, M 2 is at least one selected from the group consisting of Zr, B, Ce, V, Fe, Zn, Si, Ga, Sn, Hf, W, Mo, Cr, Nb, Mg, Hf, Ta, La, Ti, Sr, Ba, F, P, S and Y.

10. In paragraph 1, The above positive electrode active material precursor is a positive electrode active material precursor containing particles having the above polyhedral structure at 70% or more based on the total number of primary particles. 11.(A) A step of introducing a reaction solution containing a transition metal-containing solution, an ammonium ion-containing solution, and a basic aqueous solution into a reactor having a filter device installed therein; (B) a step of continuously adding a transition metal-containing solution, an ammonium ion-containing solution, and a basic aqueous solution to the reactor while maintaining the pH of the reaction solution, and performing a cathode active material precursor particle growth reaction; and (C) a step of continuously performing a cathode active material precursor particle growth reaction while continuously discharging only the reaction waste liquid to the outside of the reactor through a filter device inside the reactor when the reactor is full; A method for manufacturing a positive electrode active material precursor, wherein in the above step (B), an ammonium ion-containing solution is added so that the molar ratio of the transition metal and ammonium ion is 1:0.1 or more and 1.0 or less, and an alkaline aqueous solution is added so that the molar ratio of the transition metal and hydroxide ion is 1:1.5 or more and 2.5 or less.

12. In paragraph 11, A method for producing a positive electrode active material precursor, wherein the above transition metal-containing solution contains nickel in an amount of 60 mol% or more among transition metals.

13. In paragraph 11, A method for producing a positive electrode active material precursor, wherein the pH of the reaction solution of steps (A) and (B) above is 11 to 13.

14. In paragraph 11, A method for manufacturing a positive electrode active material precursor, wherein in the above step (B), an ammonium ion-containing solution is added so that the molar ratio of the transition metal and ammonium ion is 1:0.4 or more and 0.6 or less, and an alkaline aqueous solution is added so that the molar ratio of the transition metal and hydroxide ion is 1:1.9 or more and 2.1 or less.

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